Effect of stone coverage on soil erosion

NASA Astrophysics Data System (ADS)

Jomaa, S.; Barry, D. A.; Heng, B. P.; Brovelli, A.; Sander, G. C.; Parlange, J.

2010-12-01

Soil surface coverage has a significant impact on water infiltration, runoff and soil erosion yields. In particular, surface stones protect the soils from raindrop detachment, they retard the overland flow therefore decreasing its sediment transport capacity, and they prevent surface sealing. Several physical and environmental factors control to what extent stones on the soil surface modify the erosion rates and the related hydrological response. Among the most important factors are the moisture content of the topsoil, stone size, emplacement, coverage density and soil texture. Owing to the different inter-related processes, there is ambiguity concerning the quantitative effect of stones, and process-based understanding is limited. Experiments were performed (i) to quantify how stone features affect sediment yields, (ii) to understand the local effect of isolated surface stones, that is, the changes of the soil particle size distribution in the vicinity of a stone and (iii) to determine how stones attenuate the development of surface sealing and in turn how this affects the local infiltration rate. A series of experiments using the EPFL 6-m × 2-m erosion flume were conducted at different rainfall intensities (28 and 74 mm h-1) and stone coverage (20 and 40%). The total sediment concentration, the concentration of the individual size classes and the flow discharge were measured. In order to analyze the measurements, the Hairsine and Rose (HR) erosion model was adapted to account for the shielding effect of the stone cover. This was done by suitably adjusting the parameters based on the area not covered by stones. It was found that the modified HR model predictions agreed well with the measured sediment concentrations especially for the long time behavior. Changes in the bulk density of the topsoil due to raindrop-induced compaction with and without stone protection revealed that the stones protect the upper soil surface against the structural seals resulting in negligible changes in the bulk density during the erosion event. Since the main process contributing to surface sealing development is the compaction due to the raindrop kinetic energy and associated physico-chemical changes, the protection provided by the stone cover is consistent with the area-averaging approach used in applying the HR model.

Phase composition and morphological characterization of human kidney stones using IR spectroscopy, scanning electron microscopy and X-ray Rietveld analysis.

PubMed

Chatterjee, Paramita; Chakraborty, Arup; Mukherjee, Alok K

2018-07-05

Pathological calcification in human urinary tract (kidney stones) is a common problem affecting an increasing number of people around the world. Analysis of such minerals or compounds is of fundamental importance for understanding their etiology and for the development of prophylactic measures. In the present study, structural characterization, phase quantification and morphological behaviour of thirty three (33) human kidney stones from eastern India have been carried out using IR spectroscopy (FT-IR), powder X-ray diffraction (PXRD) and scanning electron microscopy (SEM). Quantitative phase composition of kidney stones has been analyzed following the Rietveld method. Based on the quantitative estimates of constituent phases, the calculi samples have been classified into oxalate (OX), uric acid (UA), phosphate (PH) and mixed (MX) groups. Rietveld analysis of PXRD patterns showed that twelve (36%) of the renal calculi were composed exclusively of whewellite (calcium oxalate monohydrate, COM). The remaining twenty one (64%) stones were mixture of phases with oxalate as the major constituent in fourteen (67%) of these stones. The average crystallite size of whewellite in oxalate stones, as determined from the PXRD analysis, varies between 93 (1) nm and 202 (3) nm, whereas the corresponding sizes for the uric acid and struvite crystallites in UA and PH stones are 79 (1)-155 (4) nm and 69 (1)-123(1) nm, respectively. The size of hydroxyapatite crystallites, 10 (1)-21 (1) nm, is smaller by about one order of magnitude compared to other minerals in the kidney stones. A statistical analysis using fifty (50) kidney stones (33 calculi from the present study and 17 calculi reported earlier from our laboratory) revealed that the oxalate group (whewellite, weddellite or mixture of whewellite and weddellite as the major constituent) is the most prevalent (82%) kidney stone type in eastern India. Copyright © 2018 Elsevier B.V. All rights reserved.

Management of calyceal diverticular calculi: a comparison of percutaneous nephrolithotomy and flexible ureterorenoscopy.

PubMed

Bas, Okan; Ozyuvali, Ekrem; Aydogmus, Yasin; Sener, Nevzat Can; Dede, Onur; Ozgun, Serhat; Hizli, Fatih; Senocak, Cagri; Bozkurt, Omer Faruk; Basar, Halil; Imamoglu, Abdurrahim

2015-04-01

To compare the outcomes in patients who have been treated with flexible ureterorenoscopy (f-URS) and percutaneous nephrolithotomy (PNL) in managing stone-bearing caliceal diverticula. Between April 2007 and October 2013, we performed a retrospective analysis of 54 evaluable patients (28 women and 26 men) with symptomatic stone-bearing caliceal diverticula, who underwent PNL (n = 29) or F-URS (n = 25) in four referral hospitals in Turkey. The groups were compared with respect to demographics, stone location/size, success rate, stone-free status, symptom-free status, complication rates, and hospital stay. The average stone burden preoperatively was significantly larger in patients who were treated with PNL, with the average size for f-URS being 154 ± 77 mm(2) and that for PNL being 211 ± 97 mm(2) (p = 0.023). Symptom-free rates, success rates, stone-free rates and clinically insignificant residual fragments were similar between the groups (p = 0.880 vs. p = 0.537 vs. p = 0.539, and p = 0.877, respectively). There was no statistical difference between the groups for minor complications (p = 0.521) but no major complication (Clavien III-V) occured in the f-URS group; although there were three major complications (10.3 %) (Clavien III) in the PNL group (p < 0.001). Hospitalization time per patient was 1.04 ± 0.20 days in the f-URS group, while it was 3.86 ± 1.94 days in the PNL group (p < 0.001). Even though this study clearly shows that both techniques have high overall success and symptom-free rates with similar complication rates for stone-bearing calyceal diverticulum, major complication rates may suggest consideration of the invasiveness of PNL. The f-URS procedure is advantageous with respect to a shorter hospital stay and absence of major complications. Therefore, it should be emphasized that the location of the stone and diverticula is an important factor for the selection of the procedure.

In-vitro Comminution of Model Renal Calculi using Histotripsy

PubMed Central

Duryea, Alexander P.; Maxwell, Adam D.; Roberts, William W.; Xu, Zhen; Hall, Timothy L.; Cain, Charles A.

2013-01-01

Shock wave lithotripsy (SWL) suffers from the fact that it can produce residual stone fragments of significant size (>2 mm). Mechanistically, cavitation has been shown to play an important role in the reduction of such fragments to smaller debris. In this study we assessed the feasibility of using cavitationally-based pulsed ultrasound therapy (histotripsy) to erode kidney stones. Previous work has shown that histotripsy is capable of mechanically fractionating soft tissue into fine, acellular debris. Here, we investigated the potential for translating this technology to renal calculi through the use of a commonly accepted stone model, Ultracal-30 cement. Stones were sonicated using a 1-MHz focused transducer, with 5-cycle pulses delivered at a rate of 1 kHz. Pulses having peak negative pressures ranging from 3–21 MPa were tested. Results indicate that histotripsy is capable of effectively eroding the Ultracal-30 model, achieving an average stone erosion rate of 26 mg/min at maximum treatment pressure; substantial stone erosion was only observed in the presence of a dense cavitational bubble cloud. Sequential sieving of residual stone fragments indicated that debris produced by histotripsy was smaller than 100 μm in size, and treatment monitoring showed that both the cavitational bubble cloud and model stone appear as hyperechoic regions on B-mode imaging. These preliminary results indicate that histotripsy shows promise in its use for stone comminution, and an optimized erosion process may provide a potential adjunct to conventional SWL procedures. PMID:21622053

Extracorporeal shock wave lithotripsy as first line treatment for urinary tract stones in children: outcome of 500 cases.

PubMed

Badawy, Abdelbasset A; Saleem, Mohamed D; Abolyosr, Ahmad; Aldahshoury, Mohamed; Elbadry, Mohamed S B; Abdalla, Medhat A; Abuzeid, Abdelmoneim M

2012-06-01

The continued evolution of stone treatment modalities, such as endourologic procedures, open surgery and shock wave lithotripsy, makes the assessment of continuous outcomes are essential. Pediatric urolithiasis are an important health problem allover the world, especially in Middle East region. We evaluate the safety, efficacy and factors affecting success rate and clearance of stones in children treated with shock wave lithotripsy. Between 2005 and 2010, a total of 500 children with stones in the upper urinary tract at different locations were treated by Extracorporeal shock wave lithotripsy (ESWL) in our department, Sohag University, Egypt. We have used the Siemn's Lithostar Modularis machine, Germany. A total of 371 boys and 129 girls with the average age of 8.63 ± 5 years, and a range from 9 months to 17 years were included in this study. Diagnosis of their urinary calculi was established either by the use of abdominal ultrasound, plain X-ray, intravenous urography, or CT scan. The stones were located in the kidney in 450 (90%) patients; 298 (66%) pelvic, 26 (5.7%) upper calices, 57 (12.6%) mid calices, and lower calices in 69 (15.3%) patients. The average of their stone sizes was 12.5 ± 7.2 mm. The other 50 children their stone were located in the proximal ureteral stones in 35 patients (70%); middle third in 5 (10%) patients and in the distal ureter in 10 (20%) patients. The average ureteral stone size was 7.5 ± 3.2 mm. All children were treated under general anesthesia with adequate lung and testes shielding using air foam. We treated the distal ureteral stones of young children in the supine position through greater sciatic foramen and lesser sciatic foramen as the path of shockwave instead of prone position, which is not a comfortable or natural position and could adversely affect cardiopulmonary function especially under general anesthesia. Localization was mainly done by ultrasound, and X-ray was only used to localize ureteral calculi. For follow-up, we have used abdominal ultrasound, plain X-ray, and CT scan if needed to confirm stone disintegration and clearance. The overall success rate for renal and ureteral calculi was 83.4 and 58.46%, respectively. The re-treatment rate was 4% in renal group and 28% for the ureteral group. No serious complications were recorded in our patients. Minor complications occurred in 15% of our patients; renal colic was reported in 10% of our treated patients, and repeated vomiting was reported in 5% that respond to antiemetics. In the renal group; children with history of pervious urologic surgical procedures had low success rate of stone clearance after ESWL. In the ureteral group stone burden, stone location, had a significant impact on stone clearance outcome. This study showed that SWL in pediatric age group for both renal and ureteral stone is cost effective, safe with an acceptable re-treatment rate; however children with large stone burden or previous urologic surgery have low success rate.

Natural History of Conservatively Managed Ureteral Stones: Analysis of 6600 Patients.

PubMed

Yallappa, Sachin; Amer, Tarik; Jones, Patrick; Greco, Francesco; Tailly, Thomas; Somani, Bhaskar K; Umez-Eronini, Nkem; Aboumarzouk, Omar M

2018-05-01

Ureteral colic has a lifetime prevalence of 10%-15% and is one of the most common emergency urologic presentations. Current European Association of Urology recommends conservative management for "small" (<6 mm) ureteral stones if active removal is not indicated. It is important to understand the natural history of ureteral stone disease to help counsel patients with regard to their likelihood of stone passage and anticipated time frame with which they could be safely observed. We aimed to conduct a systematic review to better establish the natural history of stone expulsion. Literature search was performed using Cochrane and PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines. Outcome measures were patient and stone demographics, expulsion rates, expulsion times, and side effect of the medication. A cumulative analysis, with subgroup analysis, was performed on stone location and size. The results were depicted as percentages and an intention-to-treat basis was used. The literature search identified 70 studies and a total of 6642 patients, with a median age of 46 and range of 18-74 years. Overall, 64% of patients successfully passed their stones spontaneously. About 49% of upper ureteral stones, 58% of midureteral stones, and 68% of distal ureteral stones passed spontaneously. Almost 75% of stones <5 mm and 62% of stones ≥5 mm passed spontaneously. The average time to stone expulsion was about 17 days (range 6-29 days). Nearly 5% of participants required rehospitalization due to a deterioration of their condition and only about 1% of patients experienced side effects from analgesia provided. We believe this current review is the largest study for the evaluation of natural history of ureteral stones. The evidence suggests that ureteral stones will pass without intervention in 64% of patients, however, this varies from nearly 50%-75% depending on the size and location, in the span of 1-4 weeks.

Distribution of organic matrix in calcium oxalate renal calculi.

PubMed

Warpehoski, M A; Buscemi, P J; Osborn, D C; Finlayson, B; Goldberg, E P

1981-01-01

The quantity of protein and carbohydrate comprising the matrix of calcium oxalate monohydrate (COM) renal stones was found to decrease with distance from the surface of the stone. The average organic concentration of stones 3 to 30 mm in diameter ranged from 5.7% at the surface to 2.7% at the core. This concentration gradient suggests matrix involvement in a "growth front" on stone surfaces with migration of organic material from the "older" interior. The matrix distribution was not readily correlated with density variations or with the presence of hydroxyapatite or calcium oxalate dihydrate. Surface matrix concentrations were greater than amounts predicted by physical adsorption. Electron microscopy confirmed the presence of the organic-rich surface layer and also suggested that increase in stone size occurs predominantly by crystal growth with microcrystal aggregates as growth centers.

Diagnostic utility of attenuation measurement (Hounsfield units) in computed tomography stonogram in predicting the radio-opacity of urinary calculi in plain abdominal radiographs.

PubMed

Chua, Michael E; Gatchalian, Glenn T; Corsino, Michael Vincent; Reyes, Buenaventura B

2012-10-01

(1) To determine the best cut-off level of Hounsfield units (HU) in the CT stonogram that would predict the appearance of a urinary calculi in plain KUB X-ray; (2) to estimate the sensitivity and specificity of the best cut-off HU; and (3) to determine whether stone size and location affect the in vivo predictability. A prospective cross-sectional study of patients aged 18-85 diagnosed with urolithiases on CT stonogram with concurrent plain KUB radiograph was conducted. Appearance of stones was recorded, and significant difference between radiolucent and radio-opaque CT attenuation level was determined using ANOVA. Receiver operating characteristics (ROC) curve determined the best HU cut-off value. Stone size and location were used for factor variability analysis. A total of 184 cases were included in this study, and the average urolithiasis size on CT stonogram was 0.84 cm (0.3-4.9 cm). On KUB X-ray, 34.2 % of the urolithiases were radiolucent and 65.8 % were radio-opaque. Mean value of CT Hounsfield unit for radiolucent stones was 358.25 (±156), and that for radio-opaque stones was 816.51 (±274). ROC curve determined the best cut-off value of HU at 498.5, with the sensitivity of 89.3 % and specificity of 87.3 %. For >4 mm stones, the sensitivity was 91.3 % and the specificity was 81.8 %. On the other hand, for =<4 mm stones, the sensitivity was 60 % and the specificity was 89.5 %. Based on the constructed ROC curve, a threshold value of 498.5 HU in CT stonogram was established as cut-off in determining whether a calculus is radio-opaque or radiolucent. The determined overall sensitivity and specificity of the set cut-off HU value are optimal. Stone size but not location affects the sensitivity and specificity.

Effect of different milling methods on glycaemic response of foods made with finger millet (Eucenea coracana) flour.

PubMed

Jayasinghe, M A; Ekanayake, S; Nugegoda, D B

2013-12-01

Compare glycaemic response of foods prepared with finger millet flour, using traditional stone grinding and industrial milling. Crossover study. Healthy volunteers (n=11) consisting of five males and six females), aged between 20 and 30 years, with a body mass index of 18.5-23.5 Kgm-2. Blood glucose concentration was measured at fasting and 30, 45, 60, 90, 120 minutes after ingestion of roti and pittu made with stone ground or industrially milled finger millet flour, containing 50 g of available carbohydrates. Glycaemic Index (GI) values were expressed as the average value of the 11 subjects. Significant differences (p<0.05) in GI between similar food types made of flour milled using different methods were observed. GI for roti made of stone ground flour was 44±5 and that of roti made of industrially milled flour was 59±7. Pittu made of stone ground flour had a GI of 67±5 and GI of pittu made of industrially milled flour was 79±5. Microscopic analysis of flour samples and a sieving process using different sieve sizes showed larger particle size distribution in stone ground flour compared to industrially milled flour. Larger particle sizes in the stone ground flour compared with industrially milled flour was established as the only factor affecting the difference in GI of same type of food prepared with flour milled using different methods. There were no significant differences (p>0.05) in proximate compositions of the different foods or raw flours. Foods prepared with finger millet (kurakkan) flour with a larger particle size distribution resulted in a lower glycaemic response.

Contribution of stone size to chronic kidney disease in kidney stone formers.

PubMed

Ahmadi, Farrokhlagha; Etemadi, Samira Motedayen; Lessan-Pezeshki, Mahbob; Mahdavi-Mazdeh, Mitra; Ayati, Mohsen; Mir, Alireza; Yazdi, Hadi Rokni

2015-01-01

To determine whether stone burden correlates with the degree of chronic kidney disease in kidney stone formers. A total of 97 extracorporeal shockwave lithotripsy candidates aged 18 years and older were included. Size, number and location of the kidney stones, along with cumulative stone size, defined as the sum of diameters of all stones) were determined. Estimated glomerular filtration rate was determined using the Chronic Kidney Disease Epidemiology Collaboration cystatin C/creatinine equation, and chronic kidney disease was defined as estimated glomerular filtration rate <60 mL/min/1.73 m(2). In individuals with cumulative stone size <20 mm, estimated glomerular filtration rate significantly decreased when moving from the first (estimated glomerular filtration rate 75.5 ± 17.8 mL/min/1.73 m(2)) to the fourth (estimated glomerular filtration rate 56.4 ± 20.44 mL/min/1.73 m(2) ) quartile (P = 0.004). When patients with a cumulative stone size ≥ 20 mm were included, the observed association was rendered non-significant. In individuals with a cumulative stone size < 20 mm, each 1-mm increase in cumulative stone size was associated with a 20% increased risk of having chronic kidney disease. The relationship persisted even after adjustment for age, sex, body mass index, C-reactive protein, fasting plasma glucose, thyroid stimulating hormone, presence of microalbuminuria, history of renal calculi, history of extracorporeal shockwave lithotripsy, number and location of the stones (odds ratio 1.24, 95% confidence interval 1.02-1.52). The same was not observed for individuals with a cumulative stone size ≥ 20 mm. In kidney stone formers with a cumulative stone size up to 20 mm, estimated glomerular filtration rate linearly declines with increasing cumulative stone size. Additionally, cumulative stone size is an independent predictor of chronic kidney disease in this group of patients. © 2014 The Japanese Urological Association.

Flexible Ureterorenoscopy for Treatment of Kidney Stones: Establishment as Primary Standard Therapy in a Tertiary Stone Center.

PubMed

Ising, Stephan; Labenski, Heike; Baltes, Stefan; Khaffaf, Aso; Thomas, Christian; Wiesner, Christoph

2015-01-01

To analyze the primary stone free rate (pSFR) of flexible ureterorenoscopy (fURS) in the treatment of renal stones and to identify clinical predictors for the primary freedom from renal stones. Two hundred and seventy five patients, who underwent fURS for kidney stones were analyzed. Index stone size was 6 mm. The stone was located in the lower calyx in 48%. Ureteral access sheath was used in 97%. Operation time was 35 min and primary stone clearance was 83%. pSFR increased from 74% in 2012 to 83% in 2013 and 90% in 2014 (p = 0.001). Preoperative stenting, index stone size, cumulative stone size, lithotripsy, ureteral access sheath and operation time were significantly correlated with the pSFR by univariate analysis. Multivariate regression analysis showed index stone size, cumulative stone size, ureteral access sheath and operation time as independent parameters for pSFR. fURS for kidney stones is safe with a high pSFR. Clinical parameters for pSFR are stone size, use of ureteral access sheath and operation time. In future, the effective use of fURS for the removal of kidney stones needs to be checked by prospective randomized trials. © 2015 S. Karger AG, Basel.

Laparoscopic management of CBD stones: an Indian experience.

PubMed

Chander, Jagdish; Vindal, Anubhav; Lal, Pawanindra; Gupta, Nikhil; Ramteke, Vinod Kumar

2011-01-01

Common bile duct stones (CBDS) that are seen in the Asian population are very different from those seen in the west. It is not infrequent to see multiple, large, and impacted stones and a hugely dilated CBD. Many of these patients have been managed by open CBD exploration (OCBDE), even after the advent of laparoscopic cholecystectomy (LC), because these large stones pose significant challenges for extraction by endoscopic retrograde cholangiopancreatography. This series presents the largest experience of managing CBDS using a laparoscopic approach from Indian subcontinent. Between 2003 and 2009, 150 patients with documented CBDS were treated laparoscopically at a tertiary care hospital in New Delhi. Of these, 4 patients were managed through transcystic route and 140 through the transcholedochal route. There were 34 men and 116 women patients with age ranging from 15 to 72 years. The mean size of the CBD on ultrasound was 11.7 ± 3.7 mm and on MRCP 13.8 ± 4.7 mm. The number of stones extracted varied from 1 to 70 and the size of the extracted stones from 5 to 30 mm. The average duration of surgery was 139.9 ± 26.3 min and the mean intraoperative blood loss was 103.4 ± 85.9 ml. There were 6 conversions to open procedures, 1 postoperative death (0.7%), and 23 patients (15%) had nonfatal postoperative complications. Three patients had retained stones (2%) and one developed recurrent stone (0.7%). Even in patients with multiple, large, and impacted CBDS, there is scope for a minimally invasive procedure with its attendant benefits in the form of laparoscopic CBD exploration (LCBDE).

Stone Attenuation Values Measured by Average Hounsfield Units and Stone Volume as Predictors of Total Laser Energy Required During Ureteroscopic Lithotripsy Using Holmium:Yttrium-Aluminum-Garnet Lasers.

PubMed

Ofude, Mitsuo; Shima, Takashi; Yotsuyanagi, Satoshi; Ikeda, Daisuke

2017-04-01

To evaluate the predictors of the total laser energy (TLE) required during ureteroscopic lithotripsy (URS) using the holmium:yttrium-aluminum-garnet (Ho:YAG) laser for a single ureteral stone. We retrospectively analyzed the data of 93 URS procedures performed for a single ureteral stone in our institution from November 2011 to September 2015. We evaluated the association between TLE and preoperative clinical data, such as age, sex, body mass index, and noncontrast computed tomographic findings, including stone laterality, location, maximum diameter, volume, stone attenuation values measured using average Hounsfield units (HUs), and presence of secondary signs (severe hydronephrosis, tissue rim sign, and perinephric stranding). The mean maximum stone diameter, volume, and average HUs were 9.2 ± 3.8 mm, 283.2 ± 341.4 mm 3 , and 863 ± 297, respectively. The mean TLE and operative time were 2.93 ± 3.27 kJ and 59.1 ± 28.1 minutes, respectively. Maximum stone diameter, volume, average HUs, severe hydronephrosis, and tissue rim sign were significantly correlated with TLE (Spearman's rho analysis). Stepwise multiple linear regression analysis defining stone volume, average HUs, severe hydronephrosis, and tissue rim sign as explanatory variables showed that stone volume and average HUs were significant predictors of TLE (standardized coefficients of 0.565 and 0.320, respectively; adjusted R 2  = 0.55, F = 54.7, P <.001). Stone attenuation values measured by average HUs and stone volume were strong predictors of TLE during URS using Ho:YAG laser procedures. Copyright © 2016 Elsevier Inc. All rights reserved.

The comparison of minimally invasive percutaneous nephrolithotomy and retrograde intrarenal surgery for stones larger than 2 cm in patients with a solitary kidney: a matched-pair analysis.

PubMed

Zeng, Guohua; Zhu, Wei; Li, Jiasheng; Zhao, Zhijian; Zeng, Tao; Liu, Chenli; Liu, Yang; Yuan, Jian; Wan, Shaw P

2015-08-01

To compare the treatment outcomes between retrograde intrarenal surgery (RIRS) and minimally invasive percutaneous nephrolithotomy (MPCNL) for the management of stones larger than 2 cm in patients with solitary kidney. Between December 2012 and March 2014, 53 patients with a solitary kidney suffering from urinary stones larger than 2 cm were treated with RIRS. The outcomes of these patients were compared to a cohort of similar solitary kidney stone patients who underwent MPCNL using a matched-pair analysis (1:1 scenario). Cases were matched sequentially using the following criteria: size, number and location of stones, age, BMI, gender and previous ipsilateral open surgery. A stone-free rate (SFR) of 43.4 % was achieved after a single procedure in patients treated with RIRS and a SFR of 71.70 % in patients treated with MPCNL (p = 0.003). The operative time for RIRS was longer (p = 0.002), but the median hospital stay was shorter (p < 0.001). Average drop in hemoglobin level was comparable in both groups (9.30 vs. 10.85 g/L, p = 0.35). The transfusion rate as well as the incidence of postoperative complications such as fever and urosepsis was not statistically different between these two groups. Major complications (Clavien score 3a-4a) occurred in 3.77 and 1.89 %, RIRS and MPCNL, respectively (p = 1.000). Patients with a solitary kidney suffering from stones larger than 2 cm in size who undergo MPCNL had a higher SFR than RIRS. The complications were comparable in both groups. Even though RIRS patients spent less time in hospital, this procedure might not be an effective treatment as MPCNL in solitary kidneys with larger and multiple stones.

Risk Factors for Stone Recurrence after Percutaneous Nephrolithotomy

NASA Astrophysics Data System (ADS)

Krambeck, Amy E.; Rangel, Laureano J.; LeRoy, Andrew J.; Patterson, David E.; Gettman, Matthew T.

2008-09-01

Recent studies have demonstrated more than 30% of percutaneous nephrolithotomy (PCNL) patients will experience a stone recurrence over a 20 year period. The goal of our study was to identify risk factors for stone recurrence after PCNL. Chart review identified 754 patients treated with PCNL for urolithiasis from March of 1983 to July 1984 at our institution. Of this cohort, 87 patients continued to receive medical care at our clinic and had been evaluated within the last 5 years. Of the 87 patients, 80 had recent radiographic imaging. Average follow-up was 19.2 years and 32 (40.0%) experienced at least 1 stone recurrence. There was no difference in preoperative BMI (p = 0.453) or change in BMI (p = 0.964) between patients that did and did not have a stone recurrence. Renal stone location (p = 0.605) and stone size (p = 0.238) were not predictive of recurrence. Patients with calcium oxalate monohydrate stones were less likely to recur (38.7% vs. 41.6%, p = 0.004) and those with calcium oxalate dihydrate (COD) were more likely to recur (31.1% vs. 19.6%, p = 0.006) compared to other compositions. Diabetes mellitus was not associated with recurrent stones (p = 0.810). Those patients with residual stones or fragments <3 mm were more likely to recur and to recur earlier than patients rendered entirely stone free at time of PCNL (p = 0.015). Stone recurrences were associated with the late development of renal insufficiency (25% vs. 2.1%, p = 0.002). In conclusion, stone composition, as well as the presence of residual fragments was associated with recurrent symptomatic stone events after PCNL. Recurrent stone events were significantly associated with the risk of developing renal insufficiency, further stressing the need for complete stone clearance at time of PCNL.

Effect of size and site on the outcome of extracorporeal shock wave lithotripsy of proximal urinary stones in children.

PubMed

Habib, Enmar I; Morsi, Hany A; Elsheemy, Mohammed S; Aboulela, Waseem; Eissa, Mohamed A

2013-06-01

To determine the effect of location and size of stones on the outcome of extracorporeal shock wave lithotripsy (ESWL) in children. In 2008-2010, 150 children (median age 6.6 years) with radio-opaque ureteric and renal stones measuring ≤4 cm were treated. Exclusion criteria were coagulation disorders, pyelonephritis, distal obstruction, non-functioning kidney and hypertension. ESWL was performed under general anesthesia. Follow up period was 5-22 months. 186 stones were treated: 76 calyceal, 92 pelvic and 18 proximal ureteral. Mean stone size was 1.3 cm. A total of 312 sessions were performed (mean per stone = 1.67 sessions). The mean number of shock waves per session was 2423.68. Overall stone-free rate was 89.24%. Having a calyceal location did not significantly affect the stone-free rate (p = 0.133). The failure rate was significantly higher (66.7%) in stones >3 cm in size (p < 0.001). Complications were encountered in 18 patients; 2 underwent auxillary ureteroscopy and 4 uretrolithotomy for treatment of steinstrasse. ESWL is a safe and effective method for treatment of stones up to 2 cm in children. Rate of auxillary procedures increases in stones >2 cm in size. About 80% of failures were associated with stone size >1.35 cm while 52.3% of completely cleared stones were associated with size <1.35 cm. Copyright © 2012 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

Endoscopic Stone Measurement During Ureteroscopy.

PubMed

Ludwig, Wesley W; Lim, Sunghwan; Stoianovici, Dan; Matlaga, Brian R

2018-01-01

Currently, stone size cannot be accurately measured while performing flexible ureteroscopy (URS). We developed novel software for ureteroscopic, stone size measurement, and then evaluated its performance. A novel application capable of measuring stone fragment size, based on the known distance of the basket tip in the ureteroscope's visual field, was designed and calibrated in a laboratory setting. Complete URS procedures were recorded and 30 stone fragments were extracted and measured using digital calipers. The novel software program was applied to the recorded URS footage to obtain ureteroscope-derived stone size measurements. These ureteroscope-derived measurements were then compared with the actual-measured fragment size. The median longitudinal and transversal errors were 0.14 mm (95% confidence interval [CI] 0.1, 0.18) and 0.09 mm (95% CI 0.02, 0.15), respectively. The overall software accuracy and precision were 0.17 and 0.15 mm, respectively. The longitudinal and transversal measurements obtained by the software and digital calipers were highly correlated (r = 0.97 and 0.93). Neither stone size nor stone type was correlated with error measurements. This novel method and software reliably measured stone fragment size during URS. The software ultimately has the potential to make URS safer and more efficient.

Can Ureteral Jet Flow Measurement Predict Spontaneous Passage of Distal Ureteral Stones?

PubMed

Ongun, Sakir; Teken, Abdurrazak; Yılmaz, Orkun; Süleyman, Sakir

2018-06-27

The study aimed to investigate the relationship between the spontaneous passage of distal ureteral stones and ureteral jet flow measurement. The study included 74 patients with acute renal colic between June 2015 and June 2016, and distal ureteral stones of 10 mm or less in a non-contrast CT were comprised in a prospective study. The ureteral jet was measured by Doppler ultrasonography. At the fourth week follow-up, kidney-ureter-bladder radiography was taken and the patients who no longer had a stone were considered to have spontaneously passed it. The average stone size of the patients was 5.6 ± 2.0 mm. After 4 weeks of follow-up, 55 patients (74.3%) had passed the stone spontaneously whereas 19 (25.6%) had not. The patients in the former group were found to have a higher peak flow velocity of ureteral jet on the stone side than those in the latter group. In regression analysis ureteral jet on the stone side was independently associated with spontaneous passage (p = 0.027). For the spontaneous passage, a ureteral jet flow peak velocity above 15.25 cm/s had an 85.4% sensitivity and 63.1% specificity. Measurement of the ureteral jet flow peak velocity can be beneficial in predicting the potential spontaneous passage of distal ureteral stones. © 2018 S. Karger AG, Basel.

[NEW OPTIONS OF ENDOSCOPIC TREATMENT FOR KIDNEY AND URETER STONES IN OBESE PATIENTS].

PubMed

Martov, A G; Dutov, S V; Andronov, A S; Kil'chukov, Z I; Tahaev, R A

2015-01-01

Effective urolithiasis treatment, especially in overweight patients has a considerable medical and social implication. Extracorporeal shock wave lithotripsy (ESWL) and percutaneous nephrolithotripsy (PCNL) in prone position of the patient are standard treatment options for kidney and ureter stones. These interventions are not always effective in patients with concomitant obesity and are associated with technical difficulties and an increased risk of complications. The study included 175 patients with obesity. The first group consisted of 96 (54.8%) patients treated with transurethral contact lithotripsy. The 2nd group consisted of 54 (30.9%) patients who underwent PCNL in the supine position. The third group comprised 25 (14.3%) patients with multiple stones of kidney and ureter, who underwent combined transurethral and percutaneous intervention in the supine position. The 1st and 3rd group had a higher prevalence of patients with II degree of obesity, in the 2nd group--with I degree of obesity. The mean duration of surgery in 1st group was 43.4 min, in the 2nd--70.3 min and in the third--84.6 min. Method of kidney drainage depended mainly on the presence, location and size of residual stone fragments. The average duration of the kidney drainage stent in patients of the 1st group was 39 days (ureteral catheter--1.3 days). In all patients of the 2nd and 3rd groups, at the final stage of the operation a nephrostomy tube was placed for an average of 2.7 days. The average postoperative hospital stay was 2.9 days in the 1st group, 4.1 days in the 2nd group and 4.5 days in the third group. In the 1st group, the stone-free status was achieved in 81 (84.4%) patients. Another 10 (10.4%) patients later needed ESWL for the complete disposal of the stones. In the 2nd group, the complete clearance of kidney stones was achieved in 49 (90.7%) patients. Another 3 (5.6%) patients required added ESWL to achieve the stone-free status. In the third group of patients stone free status was reached in 22 (88%) cases. In the remaining patients residual stone fragments were not clinically important. The most prevalent postoperative complication in all groups was postoperative pyelonephritis. Taking into account high efficiency of transurethral lithotripsy and PCNL in the supine position, as well as their combinations we can recommend these interventions to treat patients with kidney and ureteral stones and concomitant obesity.

[Factors affecting residual stones after percutaneous nephrolithotomy in patients with renal calculus].

PubMed

Qiao, Mingzhou; Zhang, Haifang; Zhou, Chenlong

2015-11-24

To explore the factors affecting the residual stones after percutaneous nephrolithotomy (PCNL) in patients with renal calculus. A retrospective analysis was performed for 1 200 patients who were affected by renal calculus and treated with PCNL between Jan 2008 and May 2014 in People's Hospital of Anyang City. Among those patients, 16 were diagnosed as bilateral renal stone and had two successive operations. The size, location and number of stones, previous history of surgery, the degree of hydronephrosis, urinary infection were included in the univariate analysis. Significant factors in univariate analysis were included in the multivariate analysis to determine factors affecting stone residual. A total of 385 cases developed stone residual after surgery. The overall residual rate was 31.7%. In univariate analysis, renal pelvis combined with caliceal calculus (P=0.006), stone size larger than 4 cm (P=0.005), stone number more than 4 (P=0.002), the amount of bleeding more than 200 ml (P=0.025), operation time longer than 120 minutes (P=0.028) were associated with an increased rate of stone residual. When subjected to the Cox multivariate analysis, the independent risk factors for residual stones were renal pelvis combined with caliceal calculus (P=0.049), stone size larger than 4 cm (P=0.038) and stone number more than 4 (P=0.018). Factors affecting the incidence of residual stones after PCNL are the size, location and number of stones. Larger size stone and the presence of renal pelvis combined with caliceal calculus are significantly associated with residual stones. Nevertheless, stone number less than 4 indicates an increased stone clearance rate.

Proof of principle in vitro study of a prototype ultrasound technology to size stone fragments during ureteroscopy.

PubMed

Sorensen, Mathew D; Teichman, Joel M H; Bailey, Michael R

2009-07-01

Proof-of-principle in vitro experiments evaluated a prototype ultrasound technology to size kidney stone fragments. Nineteen human stones were measured using manual calipers. A 10-MHz, 1/8'' (10F) ultrasound transducer probe pinged each stone on a kidney tissue phantom submerged in water using two methods. In Method 1, the instrument was aligned such that the ultrasound pulse traveled through the stone. In Method 2, the instrument was aligned partially over the stone such that the ultrasound pulse traveled through water. For Method 1, the correlation between caliper- and ultrasound-determined stone size was r(2) = 0.71 (P < 0.0001). All but two stone measurements were accurate and precise to within 1 mm. For Method 2, the correlation was r(2) = 0.99 (P < 0.0001), and measurements were accurate and precise to within 0.25 mm. The prototype technology and either method measured stone size with good accuracy and precision. This technology may be possible to incorporate into ureteroscopy.

[Large calculi of the common bile duct. Value of lithotripsy].

PubMed

Lefebvre, J F; Molkhou, J M; Bonnel, D; Dazza, F; Liguory, C

1994-01-01

Certain stones need to be fragmented before being extracted via endoscopic sphincterotomy (ES). From April 1988 to December 1991, extracorporeal lithotripsy was used in this indication in 28 patients (22 females, 6 males) with a mean age of 77 +/- 20 years, using an ultrasound-guided electrohydraulic lithotriptor. Stone detection was performed after perfusion of the nasogastric tube and was easy in 20 cases (71%), difficult in 6 cases (22%) and impossible in 2 cases (7%), which could not be treated by this method. The patients had an average of 1.4 +/- 0.9 stones measuring 19.6 +/- 8 mm and received an average of 2.480 +/- 580 shock waves in a single session for 24 patients and in two sessions for 2 patients. Radiologically obvious fragmentation was achieved in 11 out of 26 cases (42%) and was found to be effective at a further extraction attempt in 4 other cases. Complete clearance of the common bile duct was achieved in 15 cases (57.7%). The size of the stones (> or < 20 mm) and the solitary or multiple nature of the stones did not significantly influence the fragmentation results. No complication related to the technique was observed apart from the constant development of cutaneous petechiae. An improvement in the power of the generator and the use of fluoroscopic rather than ultrasonographic guidance should allow an improvement of these results in the future. Because of its safety, this lithotripsy method can be proposed following failure of mechanical lithotripsy.

Sensitivity of Noncontrast Computed Tomography for Small Renal Calculi With Endoscopy as the Gold Standard.

PubMed

Bhojani, Naeem; Paonessa, Jessica E; El Tayeb, Marawan M; Williams, James C; Hameed, Tariq A; Lingeman, James E

2018-04-03

To compare the sensitivity of noncontrast computed tomography (CT) with endoscopy for detection of renal calculi. Imaging modalities for detection of nephrolithiasis have centered on abdominal x-ray, ultrasound, and noncontrast CT. Sensitivities of 58%-62% (abdominal x-ray), 45% (ultrasound), and 95%-100% (CT) have been previously reported. However, these results have never been correlated with endoscopic findings. Idiopathic calcium oxalate stone formers with symptomatic calculi requiring ureteroscopy were studied. At the time of surgery, the number and the location of all calculi within the kidney were recorded followed by basket retrieval. Each calculus was measured and sent for micro-CT and infrared spectrophotometry. All CT scans were reviewed by the same genitourinary radiologist who was blinded to the endoscopic findings. The radiologist reported on the number, location, and size of each calculus. Eighteen renal units were studied in 11 patients. Average time from CT scan to ureteroscopy was 28.6 days. The mean number of calculi identified per kidney was 9.2 ± 6.1 for endoscopy and 5.9 ± 4.1 for CT (P <.004). The mean size of total renal calculi (sum of the longest stone diameters) per kidney was 22.4 ± 17.1 mm and 18.2 ± 13.2 mm for endoscopy and CT, respectively (P = .06). CT scan underreports the number of renal calculi, probably missing some small stones and being unable to distinguish those lying in close proximity to one another. However, the total stone burden seen by CT is, on average, accurate when compared with that found on endoscopic examination. Copyright © 2018 Elsevier Inc. All rights reserved.

Association of serum electrolytes and smoking with salivary gland stone formation.

PubMed

Yiu, A J; Kalejaiye, A; Amdur, R L; Todd Hesham, H N; Bandyopadhyay, B C

2016-06-01

To further define potential factors that may contribute to stone formation in salivary glands (sialolithiasis), a retrospective chart review was performed of patients diagnosed with sialolithiasis between March 1, 1998 and February 29, 2012. Information on salivary gland stone number, location and size, medical history, medications, and serum electrolyte levels were collected. Associations between electrolyte levels and stone characteristics (such as stone number and size) were examined. Fifty-nine patients were identified; their median age was 58 years (range 25-89 years) and most were male (95%). Salivary stones were most commonly located in the submandibular glands (83%). Thirty-five patients (59%) had a smoking history, with 16 (27%) reported as current smokers. There was a significant association between current smoker status and stone size (mean largest stone size 12.4±8.8mm vs. 7.5±4.8mm in current smokers vs. non-smokers; P=0.03). Serum sodium levels (r=0.32, P=0.014) and serum potassium levels (r=0.31, P=0.017) showed significant positive correlations with stone size. While the aetiology of sialolithiasis remains unclear, smoking (which can contribute to reduced saliva flow) and higher serum sodium levels (which can reflect volume depletion) are associated with larger salivary stones. Published by Elsevier Ltd.

Association of serum electrolytes and smoking with salivary gland stone formation

PubMed Central

Yiu, A. J.; Kalejaiye, A.; Amdur, R. L.; Hesham, H. N. Todd; Bandyopadhyay, B. C.

2016-01-01

To further define potential factors that may contribute to stone formation in salivary glands (sialolithiasis), a retrospective chart review was performed of patients diagnosed with sialolithiasis between March 1, 1998 and February 29, 2012. Information on salivary gland stone number, location, and size, medical history, medications, and serum electrolyte levels were collected. Associations between electrolyte levels and stone characteristics (such as stone number and size) were examined. Fifty-nine patients were identified; their median age was 58 years (range 25–89 years) and most were male (95%). Salivary stones were most commonly located in the submandibular glands (83%). Thirty-five patients (59%) had a smoking history, with 16 (27%) reported as current smokers. There was a significant association between current smoker status and stone size (mean largest stone size 12.4 ± 8.8 mm vs. 7.5 ± 4.8 mm in current smokers vs. non-smokers; P = 0.03). Serum sodium levels (r = 0.32, P = 0.014) and serum potassium levels (r = 0.31, P = 0.017) showed significant positive correlations with stone size. While the etiology of sialolithiasis remains unclear, smoking (which can contribute to reduced saliva flow) and higher serum sodium levels (which can reflect volume depletion) are associated with larger salivary stones. PMID:26969301

Percutaneous nephrolithotomy versus extracorporeal shock wave lithotripsy for moderate sized kidney stones.

PubMed

Deem, Samuel; Defade, Brian; Modak, Asmita; Emmett, Mary; Martinez, Fred; Davalos, Julio

2011-10-01

To compare the outcomes of percutaneous nephrolithotomy (PNL) and extracorporeal shock wave lithotripsy (ESWL) for moderate sized (1-2 cm) upper and middle pole renal calculi in regards to stone clearance rate, morbidity, and quality of life. All patients diagnosed with moderate sized upper and middle pole kidney stones by computed tomography (CT) were offered enrollment. They were randomized to receive either ESWL or PNL. The SF-8 quality of life survey was administered preoperatively and at 1 week and 3 months postoperatively. Abdominal radiograph at 1 week and CT scan at 3 months were used to determine stone-free status. All complications and outcomes were recorded. PNL established a stone-free status of 95% and 85% at 1 week and 3 months, respectively, whereas ESWL established a stone-free status of 17% and 33% at 1 week and 3 months, respectively. Retreatment in ESWL was required in 67% of cases, with 0% retreatment in PNL. Stone location, stone density, and skin-to-stone distance had no impact on stone-free rates at both visits, irrespective of procedure. Patient-reported outcomes, including overall physical and mental health status, favored a better quality of life for patients who had PNL performed. PNL more often establishes stone-free status, has a more similar complication profile, and has similar reported quality of life at 3 months when compared with ESWL for moderate-sized kidney stones. PNL should be offered as a treatment option to all patients with moderate-sized kidney stones in centers with experienced endourologists. Copyright © 2011 Elsevier Inc. All rights reserved.

Coupled CFD-PBE Predictions of Renal Stone Size Distributions in the Nephron in Microgravity

NASA Technical Reports Server (NTRS)

Kassemi, Mohammad; Griffin, Elise; Thompson, David

2016-01-01

In this paper, a deterministic model is developed to assess the risk of critical renal stone formation for astronauts during space travel. A Population Balance Equation (PBE) model is used to compute the size distribution of a population of nucleating, growing and agglomerating renal calculi as they are transported through different sections of the nephron. The PBE model is coupled to a Computational Fluid Dynamics (CFD) model that solves for steady state flow of urine and transport of renal calculi along with the concentrations of ionic species, calcium and oxalate, in the nephron using an Eulerian two-phase mathematical framework. Parametric simulation are performed to study stone size enhancement and steady state volume fraction distributions in the four main sections of the nephron under weightlessness conditions. Contribution of agglomeration to the stone size distribution and effect of wall friction on the stone volume fraction distributions are carefully examined. Case studies using measured astronaut urinary calcium and oxalate concentrations in microgravity as input indicate that under nominal conditions the largest stone sizes developed in Space will be still considerably below the critical range for problematic stone development. However, results also indicate that the highest stone volume fraction occurs next to the tubule and duct walls. This suggests that there is an increased potential for wall adhesion with the possibility of evolution towards critical stone sizes.

Risk factors for recurrent symptomatic pigmented biliary stones after percutaneous transhepatic biliary extraction.

PubMed

Kim, Dong Won; Lee, Sang Yun; Cho, Jin-Han; Kang, Myong Jin; Noh, Myung Hwan; Park, Byeong-Ho

2010-07-01

To evaluate risk factors for the recurrence of biliary stones after a percutaneous transhepatic biliary stone extraction. The procedures were performed on 339 patients between July 2004 and December 2008 (54 months). Medical records and images were retrospectively reviewed for 135 patients (mean age, 66.4 years; 83 men and 52 women) who had undergone follow-up for a mean of 13.2 months (range, 3-37 months). To evaluate risk factors for the recurrence of biliary stones, variables were evaluated with univariate and multivariate analyses. Variables included sex, age, stone location, number of stones, stone size, presence of a peripapillary diverticulum, application of antegrade sphincteroplasty, presence of a biliary stricture, largest biliary diameter before the procedure, and gallbladder status. Thirty-three of the 135 patients (24%) had recurrent symptomatic biliary stones and underwent an additional extraction. The mean time to recurrence was 17.2 months +/- 8.7. Univariate analysis of risk factors for recurrence of biliary stones demonstrated that location, number of stones, stone size, application of antegrade sphincteroplasty, presence of a biliary stricture, and biliary diameter were significant factors (P < .05). With use of multivariate analysis, the number of stones (> or =6; relative risk, 64.8; 95% confidence interval: 5.8, 717.6) and stone size (> or =14 mm; relative risk, 3.8; 95% confidence interval: 1.138, 13.231) were determined to be significant risk factors. The independent risk factors for recurrence of symptomatic biliary stones after percutaneous transhepatic biliary stone extraction were a stone size of at least 14 mm and the presence of at least six stones. Copyright 2010 SIR. Published by Elsevier Inc. All rights reserved.

Analysis of Changes in the Glomerular Filtration Rate as Measured by the Cockroft-Gault Formula in the Early Period after Percutaneous Nephrolithotomy

PubMed Central

Seckiner, Ilker; Erturhan, Sakip M.; Mizrak, Sedat; Erbagci, Ahmet

2012-01-01

Purpose We aimed to analyze the changes in kidney function during the postoperative early period caused by the application of percutaneous nephrolithotomy (PNL), which is commonly used in kidney stone surgery. Materials and Methods PNL was performed in 80 patients (48 men, 32 women) with kidney stones. The mean age of the patients was 43.71 years (range, 18 to 71 years). Preoperative and postoperative values for stone size, glomerular filtration rate (GFR), serum creatinine, urea, electrolytes (Na, K, Cl), and Hb were compared in 80 patients in whom PNL surgery was performed. The formula of Cockroft-Gault was used to calculate the GFR during the early postoperative period (72 to 96 hours). Results Statistically significant decreases after PNL were observed in average stone size (preoperative, 627.75±375.10 mm2; postoperative, 81.70±16.15 mm2), serum urea (preoperative, 38.40±17.26 mg/dl; postoperative, 33.28±16.98 mg/dl), and creatinine (preoperative, 1.03±0.53 mg/dl; postoperative, 0.97±0.55 mg/dl) and an increase was observed in GFR (preoperative, 104.30±37.30 ml/min; postoperative, 112.38±40.1 ml/min). No changes were detected in the serum electrolyte values (Na, K, Cl). Multiple access, operation time, and type of lithotripter did not have any significant effects on the change in the GFR. Conclusions In light of our results, PNL for kidney stone operations appears to be a reliable and efficient method that provides recovery of kidney functions in the early post-operative period by increasing the GFR and with high stone-free rates. PMID:22950000

Size and Location of Defects at the Coupling Interface Affect Lithotripter Performance

PubMed Central

Li, Guangyan; Williams, James C.; Pishchalnikov, Yuri A.; Liu, Ziyue; McAteer, James A.

2012-01-01

OBJECTIVE To determine how the size and location of coupling defects caught between the therapy head of a lithotripter and the skin of a surrogate patient (acoustic window of a test chamber) affect the features of shock waves responsible for stone breakage. METHODS Model defects were placed in the coupling gel between the therapy head of a Dornier Compact-S electromagnetic lithotripter and the Mylar window of a water-filled coupling test system. A fiber-optic hydrophone was used to measure acoustic pressures and map the lateral dimensions of the focal zone of the lithotripter. The effect of coupling conditions on stone breakage was assessed using Gypsum model stones. RESULTS Stone breakage decreased in proportion to the area of the coupling defect; a centrally located defect blocking only 18% of the transmission area reduced stone breakage by an average of almost 30%. The effect on stone breakage was greater for defects located on-axis and decreased as the defect was moved laterally; an 18% defect located near the periphery of the coupling window (2.0 cm off-axis) reduced stone breakage by only ~15% compared to when coupling was completely unobstructed. Defects centered within the coupling window acted to narrow the focal width of the lithotripter; an 8.2% defect reduced the focal width ~30% compared to no obstruction (4.4 mm versus 6.5 mm). Coupling defects located slightly off center disrupted the symmetry of the acoustic field; an 18% defect positioned 1.0 cm off-axis shifted the focus of maximum positive pressure ~1.0 mm laterally. Defects on and off-axis imposed a significant reduction in the energy density of shock waves across the focal zone. CONCLUSIONS In addition to blocking the transmission of shock wave energy, coupling defects also disrupt the properties of shock waves that play a role in stone breakage, including the focal width of the lithotripter and the symmetry of the acoustic field; the effect is dependent on the size and location of defects, with defects near the center of the coupling window having the greatest effect. These data emphasize the importance of eliminating air pockets from the coupling interface, particularly defects located near the center of the coupling window. PMID:22938566

A Comparison of Retrograde Intrarenal Surgery and Percutaneous Nephrolithotomy for Management of Renal Stones ?2 CM.

PubMed

Sari, Sercan; Ozok, Hakki Ugur; Cakici, Mehmet Caglar; Ozdemir, Harun; Bas, Okan; Karakoyunlu, Nihat; Sagnak, Levent; Senturk, Aykut Bugra; Ersoy, Hamit

2017-01-18

In this retrospective study, we aimed to compare the outcomes in patients who have been treated withpercutaneous nephrolithotomy (PNL) and retrograde intrarenal surgery (RIRS) on renal stones ≥ 2 cm size. We evaluated patients who underwent PNL or RIRS for renal stones ≥ 2 cm size betweenNovember 2011 and November 2014. Stone size, operation, fluoroscopy and hospitalization time, success rates,stone-free rates and complication rates were compared in both groups. Patients were followed for three months. 254 patients were in the PNL Group. 185 patients were in the RIRS Group. The mean age was 46.88 and48.04 years in PNL and RIRS groups, respectively.The patient and stone characteristics (age, gender, Body Mass Index, kidney anomaly, SWL history and stoneradioopacity) were similar between two groups.The mean stone size preoperatively was significantly larger in patients who were treated with PNL (26.33mm.vs24.04mm.; P = .006). In the RIRS group, the mean stone number was significantly higher than PNL group (P <.001).The mean operative, fluoroscopy and hospitalization time were significantly higher in PNL group (P < .001). Thestone-free rate was 93.3% for the PNL group and 73.5% for the RIRS group after first procedure (P < .001). Nomajor complication (Clavien III-V) occurred in the RIRS group. Although the primary treatment method for renal stones ≥ 2cm size is PNL, serious complicationscan be seen. Therefore, RIRS can be an alternative treatment option in the management of renal stones ≥2 cm size.

Stone Comminution Correlates with the Average Peak Pressure Incident on a Stone during Shock Wave Lithotripsy

PubMed Central

Smith, N.; Zhong, P.

2012-01-01

To investigate the roles of lithotripter shock wave (LSW) parameters and cavitation in stone comminution, a series of in vitro fragmentation experiments have been conducted in water and 1,3-butanediol (a cavitation-suppressive fluid) at a variety of acoustic field positions of an electromagnetic shock wave lithotripter. Using field mapping data and integrated parameters averaged over a circular stone holder area (Rh = 7 mm), close logarithmic correlations between the average peak pressure (P+(avg)) incident on the stone (D = 10 mm BegoStone) and comminution efficiency after 500 and 1,000 shocks have been identified. Moreover, the correlations have demonstrated distinctive thresholds in P+(avg) (5.3 MPa and 7.6 MPa for soft and hard stones, respectively), that are required to initiate stone fragmentation independent of surrounding fluid medium and LSW dose. These observations, should they be confirmed using other shock wave lithotripters, may provide an important field parameter (i.e., P+(avg)) to guide appropriate application of SWL in clinics, and facilitate device comparison and design improvements in future lithotripters. PMID:22935690

Stone comminution correlates with the average peak pressure incident on a stone during shock wave lithotripsy.

PubMed

Smith, N; Zhong, P

2012-10-11

To investigate the roles of lithotripter shock wave (LSW) parameters and cavitation in stone comminution, a series of in vitro fragmentation experiments have been conducted in water and 1,3-butanediol (a cavitation-suppressive fluid) at a variety of acoustic field positions of an electromagnetic shock wave lithotripter. Using field mapping data and integrated parameters averaged over a circular stone holder area (R(h)=7 mm), close logarithmic correlations between the average peak pressure (P(+(avg))) incident on the stone (D=10 mm BegoStone) and comminution efficiency after 500 and 1000 shocks have been identified. Moreover, the correlations have demonstrated distinctive thresholds in P(+(avg)) (5.3 MPa and 7.6 MPa for soft and hard stones, respectively), that are required to initiate stone fragmentation independent of surrounding fluid medium and LSW dose. These observations, should they be confirmed using other shock wave lithotripters, may provide an important field parameter (i.e., P(+(avg))) to guide appropriate application of SWL in clinics, and facilitate device comparison and design improvements in future lithotripters. Copyright © 2012 Elsevier Ltd. All rights reserved.

Multichannel impedance monitoring for evaluation of alpha-adrenoblocker effect on the ureteral function in patients with stone disease

NASA Astrophysics Data System (ADS)

Apolikhin, O. I.; Khodyreva, L. A.; Mudraya, I. S.; Kirpatovsky, V. I.; Serdyuk, A. A.

2010-04-01

The study of distal ureter function was carried out on patients with stones in the upper urinary tract, who underwent ureteroscopy and lithotripsy procedures. The parameters of ureteral peristalsis such as peristalsis amplitude, peristalsis rate, ureteral wall tone, contractile wave duration, and its direction obtained by multichannel impedance ureterography were assessed and compared from two groups of patients. The group I patients received tamsulosin in addition to standard regimen, while the group II patients matched according to the stone size and location were managed without tamsulosin medical therapy. In comparison with group II, the group I patients demonstrated smaller average peristalsis amplitude (0.60±0.08 vs 0.81±0.06 Ohm), shorter contractions (7.1±0.3 vs 7.7±0.3 s), greater peristalsis rate (3.3±0.3 vs 2.8±0.2 per minute), and diminished ureteral tone (4.0±0.5 vs 4.7±0.2 Ohm-1). Incidence of the retrograde contractile waves was two-fold greater in the group II, while normal antegrade regular contractions were 30% more frequent in the group I. In addition, our results showed that the effect of tamsulosin on ureteral function was manifested in the patients with different stone size and location in the upper urinary tract, and it depended pronouncedly on individual ureteral tone and contractility parameters.

Percutaneous cystolithotripsy using self-retaining laparoscopic trocar for management of large bladder stones.

PubMed

Elbahnasy, Abdelhamid M; Farhat, Yasser A; Aboramadan, Ahmad R; Taha, Mohamed Rasheed

2010-12-01

Percutaneous endoscopic management of bladder stones is not new. The ideal technique to establish suprapubic access, however, is still not justified. In this study, we used the 12-mm self-retaining laparoscopic trocar for access during management of large bladder stones. With the patient in the lithotomy position, a 12-mm self-retaining laparoscopic trocar was inserted in a full bladder under cystoscopic visual control. A 28F nephroscope was used to fragment the stone using ultrasound and pneumoclast lithotriptors. After stone treatment, the trocar was left in place, and transurethral resection of the prostate (TURP) was completed when indicated. Both urethral and suprapubic catheters were left at the end of the procedure. Clinical examination, urinalysis, and ultrasonographic examination were routinely performed during follow-up visits. The mean stone size was 4.07 + 0.20 cm (2.8-6 cm). The average time for stone fragmentation was 32.78 + 2.16 minutes (range 8-53 min). A concomitant TURP was performed in 12 patients. The mean hospital stay was 2.56 + 0.15 days (range 1-4 days). All patients were stone free, and a total of six complications occurred, including extravasation, one patient; hematuria, two patients; and fever, three patients. All were treated conservatively. The mean follow-up time was 15.65 + 1.51 months (range 9-36 mos). Suprapubic percutaneous cystolithotripsy is a safe, minimally invasive alternative for management of large bladder stones. The use of a self-retaining trocar facilitates access and allows use of a large nephroscope for rapid fragmentation and extraction of the stone fragments. The presence of specific trocars for suprapubic access into the urinary bladder will encourage more transvesical end-laparoscopic procedures.

Spontaneous passage of ureteral stones in patients with indwelling ureteral stents.

PubMed

Baumgarten, Lee; Desai, Anuj; Shipman, Scott; Eun, Daniel D; Pontari, Michel A; Mydlo, Jack H; Reese, Adam C

2017-10-01

To determine rates of spontaneous ureteral stone passage in patients with indwelling ureteral stents, and to identify factors associated with the spontaneous passage of stones while a ureteral stent is in place. From our institutional database, we identified patients who underwent ureteroscopic procedures for stone disease between January 1, 2013 and March 1, 2015. We compared the rates of spontaneous stone passage between patients who had previously undergone ureteral stent placement and those who had not. In patients with indwelling stents, multivariate logistic regression was performed to identify factors associated with spontaneous stone passage. A total of 194 patients met inclusion criteria. Spontaneous stone passage rates were similar in the stented (17/119, 14%) and non-stented (15/75, 20%) groups (p = 0.30). In bivariate analysis of stented patients, smaller stone size (p < 0.001) and distal stone location (p = 0.01) were significantly associated with spontaneous stone passage. Multivariate logistic regression analysis of stented patients showed that only small stone size was significantly associated with the likelihood of stone passage (p = 0.01), whereas stent duration, stone location, and stone laterality were not. A small, but clinically significant percentage of ureteral stones pass spontaneously with a ureteral stent in place. Small stone size is associated with an increased likelihood of spontaneous passage in patients with indwelling stents. These findings may help to identify patients who can potentially avoid additional surgical procedures for definitive stone removal after ureteral stent placement.

Pediatric ureteroscopic management of intrarenal calculi.

PubMed

Tanaka, Stacy T; Makari, John H; Pope, John C; Adams, Mark C; Brock, John W; Thomas, John C

2008-11-01

Data addressing ureteroscopic management of intrarenal calculi in prepubertal children are limited. We reviewed our experience from January 2002 through December 2007. We retrospectively reviewed ureteroscopic procedures for intrarenal calculi in children younger than 14 years. Stone-free status was determined with postoperative imaging. Multiple logistic regression analysis was used to assess the influence of preoperative factors on initial stone-free status and the need for additional procedures. Intrarenal calculi were managed ureteroscopically in 52 kidneys in 50 children with a mean age of 7.9 years (range 1.2 to 13.6). Mean stone size was 8 mm (range 1 to 16). Stone-free rate after a single ureteroscopic procedure was 50% (25 of 50 patients) on initial postoperative imaging and 58% (29 of 50) with extended followup. Initial stone-free status was dependent on preoperative stone size (p = 0.005) but not stone location. Additional stone procedures were required in 18 upper tracts. Younger patient age (p = 0.04) and larger preoperative stone size (p = 0.002) were associated with the need for additional procedures. Additional procedures were required in more than half of the stones 6 mm or larger but in no stone smaller than 6 mm. Ureteroscopy is a safe method for the treatment of intrarenal calculi in the prepubertal population. Our ureteroscopic stone-free rate for intrarenal stones is lower than that reported for ureteral stones. Parents should be informed that additional procedures will likely be required, especially in younger patients and those with stones larger than 6 mm.

Randomized controlled trial of febuxostat versus allopurinol or placebo in individuals with higher urinary uric acid excretion and calcium stones.

PubMed

Goldfarb, David S; MacDonald, Patricia A; Gunawardhana, Lhanoo; Chefo, Solomon; McLean, Lachy

2013-11-01

Higher urinary uric acid excretion is a suspected risk factor for calcium oxalate stone formation. Febuxostat, a xanthine oxidoreductase inhibitor, is effective in lowering serum urate concentration and urinary uric acid excretion in healthy volunteers and people with gout. This work studied whether febuxostat, compared with allopurinol and placebo, would reduce 24-hour urinary uric acid excretion and prevent stone growth or new stone formation. In this 6-month, double-blind, multicenter, randomized controlled trial, hyperuricosuric participants with a recent history of calcium stones and one or more radio-opaque calcium stone ≥ 3 mm (as seen by multidetector computed tomography) received daily febuxostat at 80 mg, allopurinol at 300 mg, or placebo. The primary end point was percent change from baseline to month 6 in 24-hour urinary uric acid. Secondary end points included percent change from baseline to month 6 in size of index stone and change from baseline in the mean number of stones and 24-hour creatinine clearance. Of 99 enrolled participants, 86 participants completed the study. Febuxostat led to significantly greater reduction in 24-hour urinary uric acid (-58.6%) than either allopurinol (-36.4%; P=0.003) or placebo (-12.7%; P<0.001). Percent change from baseline in the size of the largest calcium stone was not different with febuxostat compared with allopurinol or placebo. There was no change in stone size, stone number, or renal function. No new safety concerns were noted for either drug. Febuxostat (80 mg) lowered 24-hour urinary uric acid significantly more than allopurinol (300 mg) in stone formers with higher urinary uric acid excretion after 6 months of treatment. There was no change in stone size or number over the 6-month period.

Pilot Study of Low-Dose Nonenhanced Computed Tomography With Iterative Reconstruction for Diagnosis of Urinary Stones

PubMed Central

Park, Sang Ho; Moon, Young Tae; Myung, Soon Chul; Kim, Tae Hyoung; Chang, In Ho; Kwon, Jong Kyou

2014-01-01

Purpose To evaluate the efficacy of low-dose computed tomography (LDCT) for detecting urinary stones with the use of an iterative reconstruction technique for reducing radiation dose and image noise. Materials and Methods A total of 101 stones from 69 patients who underwent both conventional nonenhanced computed tomography (CCT) and LDCT were analyzed. Interpretations were made of the two scans according to stone characteristics (size, volume, location, Hounsfield unit [HU], and skin-to-stone distance [SSD]) and radiation dose by dose-length product (DLP), effective dose (ED), and image noise. Diagnostic performance for detecting urinary stones was assessed by statistical evaluation. Results No statistical differences were found in stone characteristics between the two scans. The average DLP and ED were 384.60±132.15 mGy and 5.77±1.98 mSv in CCT and 90.08±31.80 mGy and 1.34±0.48 mSv in LDCT, respectively. The dose reduction rate of LDCT was nearly 77% for both DLP and ED (p<0.01). The mean objective noise (standard deviation) from three different areas was 23.0±2.5 in CCT and 29.2±3.1 in LDCT with a significant difference (p<0.05); the slight increase was 21.2%. For stones located throughout the kidney and ureter, the sensitivity and specificity of LDCT remained 96.0% and 100%, with positive and negative predictive values of 100% and 96.2%, respectively. Conclusions LDCT showed significant radiation reduction while maintaining high image quality. It is an attractive option in the diagnosis of urinary stones. PMID:25237459

Prediction of renal crystalline size distributions in space using a PBE analytic model. 2. Effect of dietary countermeasures.

PubMed

Kassemi, Mohammad; Thompson, David

2016-09-01

An analytic Population Balance Equation model is used to assess the efficacy of citrate, pyrophosphate, and augmented fluid intake as dietary countermeasures aimed at reducing the risk of renal stone formation for astronauts. The model uses the measured biochemical profile of the astronauts as input and predicts the steady-state size distribution of the nucleating, growing, and agglomerating renal calculi subject to biochemical changes brought about by administration of these dietary countermeasures. Numerical predictions indicate that an increase in citrate levels beyond its average normal ground-based urinary values is beneficial but only to a limited extent. Unfortunately, results also indicate that any decline in the citrate levels during space travel below its normal urinary values on Earth can easily move the astronaut into the stone-forming risk category. Pyrophosphate is found to be an effective inhibitor since numerical predictions indicate that even at quite small urinary concentrations, it has the potential of shifting the maximum crystal aggregate size to a much smaller and plausibly safer range. Finally, our numerical results predict a decline in urinary volume below 1.5 liters/day can act as a dangerous promoter of renal stone development in microgravity while urinary volume levels of 2.5-3 liters/day can serve as effective space countermeasures. Copyright © 2016 the American Physiological Society.

Determinants of holmium:yttrium-aluminum-garnet laser time and energy during ureteroscopic laser lithotripsy.

PubMed

Molina, Wilson R; Marchini, Giovanni S; Pompeo, Alexandre; Sehrt, David; Kim, Fernando J; Monga, Manoj

2014-04-01

To evaluate the association of preoperative noncontrast computed tomography stone characteristics, laser settings, and stone composition with cumulative holmium:yttrium-aluminum-garnet (Ho:YAG) laser time/energy. We retrospectively reviewed patients who underwent semirigid/flexible ureteroscopy and Ho:YAG laser lithotripsy (200 or 365 μm laser fiber; 0.8-1.0 J energy; and 8-10 Hz rate) at 2 tertiary care centers (April 2010-May 2012). Studied parameters were as follows: patient's characteristics; stone characteristics (location, burden, hardness, and composition); total laser time and energy; and surgical outcomes. One hundred patients met our inclusion criteria. Mean stone size was 1.01 ± 0.42 cm and volume 0.33 ± 0.04 cm(3). Mean stone radiodensity was 990 ± 296 HU, and Hounsfield units density 13.8 ± 6.0 HU/mm. All patients were considered stone free. Stone size and volume had a significant positive correlation with laser energy (R = 0.516, P <.001; R = 0.621, P <.001) and laser time (R = 0.477, P <.001; R = 0.567, P <.001). When controlling for stone size, only the correlation between HU and laser time was significant (R = 0.262, P = .011). In the multivariate analysis, with exception of stone composition (P = .103), all parameters significantly increased laser energy (R(2) = 0.524). Multivariate analysis revealed a positive significant association of laser time with stone volume (P <.001) and Hounsfield units density (P <.001; R(2) = 0.512). In multivariate analysis for laser energy, only calcium phosphate stones required less energy to fragment compared with uric acid stones. No significant differences were found in the multivariate laser time model. Ho:YAG laser cumulative energy and total time are significantly affected by stone dimensions, hardness location, fiber size, and power. Kidney location, laser fiber size, and laser power have more influence on the final laser energy than on the total laser time. Calcium phosphate stones require less laser energy to fragment. Copyright © 2014 Elsevier Inc. All rights reserved.

Combined retrograde flexible ureteroscopic lithotripsy with holmium YAG laser for renal calculi associated with ipsilateral ureteral stones.

PubMed

Cocuzza, Marcello; Colombo, Jose R; Ganpule, Arvind; Turna, Burak; Cocuzza, Antonio; Dhawan, Divyar; Santos, Bruno; Mazzucchi, Eduardo; Srougi, Miguel; Desai, Mahesh; Desai, Mihir

2009-02-01

The purpose of this study was to evaluate the effectiveness of combined ureteroscopic holmium YAG lithotripsy for renal calculi associated with ipsilateral ureteral stones. Between August 2002 and March 2007, retrograde flexible ureteroscopic stone treatment was attempted in 351 cases. Indication for treatment was concurrent symptomatic ureteral stones in 63 patients (group I). Additional operative time and perioperative complication rates were compared to a group of 39 patients submitted to ureteroscopic treatment for ureteral calculi exclusively (group II). Mean ureteral stone size was 8.0 +/- 2.6 mm and 8.1 +/- 3.4 mm for groups I and II, respectively. Mean operative time for group I was 67.9 +/- 29.5 minutes and for group 2 was 49.3 +/- 13.2 minutes (p < 0.001). Flexible ureteroscopic therapy for renal calculi increased 18 minutes in the mean operative time. The overall complication rate was 3.1% and 2.5% for groups I and II, respectively (p = 0.87). Mean renal stone size was 10.7 +/- 6.4 mm, overall stone free rate in group I was 81%. However, considering only patients with renal stones smaller than 15 mm, the stone free rate was 88%. Successful treatment occurred in 81% of patients presenting lower pole stones, but only 76% of patients with multiple renal stones became stone free. As expected, stone free rate showed a significant negative correlation with renal stone size (p = 0.03; r = -0.36). Logistic regression model indicated an independent association of renal stones smaller than 15 mm and stone free rate (OR = 13.5; p = 0.01). Combined ureteroscopic treatment for ureteral and ipsilateral renal calculi is a safe and attractive option for patients presenting for symptomatic ureteral stone and ipsilateral renal calculi smaller than 15 mm.

Outcomes of Conservative Management of Asymptomatic Live Donor Kidney Stones.

PubMed

Sarier, Mehmet; Duman, Ibrahim; Callioglu, Mehmet; Soylu, Ahmet; Tekin, Sabri; Celep, Emrah; Turan, Hasan; Yavuz, Asuman Havva; Demirbas, Alper; Kukul, Erdal

2018-05-10

To evaluate the long-term outcomes of asymptomatic stones ≤4 mm which are left in situ during renal transplantation (RT). Between 2009 and 2017, 31 patients who received stone-bearing (≤4 mm) kidneys were analyzed. At their last follow-up, the patients were evaluated with CT imaging and the results were compared to the initial CT findings obtained during donor evaluation. The mean stone size was 2.9mm (range 1-4.3). The mean follow-up period after RT was 43.1 months (range 12-97). According to the CT findings of the last follow-up, the stone had passed spontaneously in 26(83.9%) patients. Three patients (9.6%) with a stone size of 4 mm required surgical intervention because the stone became symptomatic within the first year after transplantation. In the remaining 2 patients (6.4%), the stone remained in situ, without a change in its size. In terms of spontaneous passage rate, there was no significant difference between lower and mid-upper pole stones (p=0.948). De novo stone formation was observed in 2(6.4%) patients. Asymptomatic stones <4 mm which are detected on donor evaluation may safely be left in situ during RT. Regardless of their localization in the kidney, these stones have high spontaneous passage rates after RT, and the long-term recurrence rates are also considerably low. Copyright © 2018 Elsevier Inc. All rights reserved.

Determination of exposure to respirable quartz in the stone crushing units at Azendarian-West of Iran.

PubMed

Bahrami, Abdul Rahman; Golbabai, Faridah; Mahjub, Hossien; Qorbani, Farshid; Aliabadi, Mohsan; Barqi, Mohamadali

2008-08-01

The purpose of this study is to describe the personal exposure to respirable dust and quartz and in stone crushing units located at west of Iran. A size of 40 personal samples and 40 stationary samples were obtained and analysis was done by X-ray diffraction (XRD). The results of personal sampling were shown the concentrations of respirable dust exposure level in workers of process, hopper and drivers were 1.90, 2.22, 1.41 times greater than Occupational Safety and Health Administration permissible exposure limit (OSHA PEL). The average value of total dust and respirable dust emission from stationary sources was 9.46 mg/m(3), 1.24 mg/m(3) respectively, showing that 13.8 % of total dust is respirable. The efficiency of local exhaust ventilation (LEV) to control of particles inside of industrial units was greater than 99%. It is concluded from this research the particulate generated from stone crushing activities contain a significant amount of respirable particle. The amount of free silica in stone quartz is 85 to 97 percent that emission of particles effect to health workers. LEV has important effect in the removal of silica particles in stone crushing units. The worker of hoppers still exposed to silica more than standard limits.

Relationship Between Ureteral Jet Flow, Visual Analogue Scale, and Ureteral Stone Size.

PubMed

Ongun, Sakir; Teken, Abdurrazak; Yılmaz, Orkun; Süleyman, Sakir

2017-06-01

To contribute to the diagnosis and treatment of ureteral stones by investigating the relationship between the ureteral jet flow measurements of patients with ureteral stones and the size of the stones and the patients' pain scores. The sample consisted of patients who presented acute renal colic between December 2014 and 2015 and from a noncontrast computed tomography were found to have a urinary stone. The ureteral jet flow velocities were determined using Doppler ultrasonography. The patients were all assessed in terms of stone size, localization and area, anteroposterior pelvis (AP) diameter, and visual analogue scale (VAS) scores. A total of 102 patients were included in the study. As the VAS score decreased, the peak jet flow velocity on the stone side increased, whereas the flow velocity on the other side, AP diameter, and stone area were reduced (P < .05). As the stone size increased, the peak jet flow velocity was reduced and the AP diameter increased significantly (P < .05). Ureteral jet flow was not observed in 17 patients on the stone side. A statistically significant difference was found between these patients and the remaining patients in terms of all parameters (P < .05). For patients, in whom the peak flow velocity of ureteral jet is low and with a severe level of pain or the peak flow velocity of ureteral jet cannot be measured, there is a low possibility of spontaneous passage and a high possibility of a large stone, and therefore the treatment should be started immediately. Copyright © 2017 Elsevier Inc. All rights reserved.

Effect of Stone Size and Composition on Ultrasonic Propulsion Ex Vivo.

PubMed

Janssen, Karmon M; Brand, Timothy C; Bailey, Michael R; Cunitz, Bryan W; Harper, Jonathan D; Sorensen, Mathew D; Dunmire, Barbrina

2018-01-01

To evaluate in more detail the effectiveness of a new designed more efficient ultrasonic propulsion for large stones and specific stone compositions in a tissue phantom model. In the first clinical trial of noninvasive ultrasonic propulsion, urinary stones of unknown compositions and sizes up to 10 mm were successfully repositioned. The study included 8- to 12-mm stones of 4 different primary compositions (calcium oxalate monohydrate, ammonium acid urate, calcium phosphate, and struvite) and a renal calyx phantom consisting of a 12 mm × 30 mm well in a 10-cm block of tissue-mimicking material. Primary outcome was the number of times a stone was expelled over 10 attempts, with ultrasonic propulsion burst duration varying from 0.5 seconds to 5 seconds. Overall success rate at expelling stones was 95%. All calcium oxalate monohydrate and ammonium acid urate stones were expelled 100% of the time. The largest stone (12 mm) became lodged within the 12-mm phantom calyx 25% of the time regardless of the burst duration. With the 0.5-second burst, there was insufficient energy to expel the heaviest stone (0.88 g), but there was sufficient energy at the longer burst durations. With a single burst, ultrasonic propulsion successfully moved most stones at least 3 cm and, regardless of size or composition, expelled them from the calyx. Ultrasonic propulsion is limited to the stones smaller than the calyceal space, and for each burst duration, related to maximum stone mass. Published by Elsevier Inc.

Effect of Stone Size and Composition on Ultrasonic Propulsion Ex Vivo

PubMed Central

Janssen, Karmon M.; Brand, Timothy C.; Bailey, Michael R.; Cunitz, Bryan W.; Harper, Jonathan D.; Sorensen, Mathew D.; Dunmire, Barbrina

2018-01-01

OBJECTIVE To evaluate in more detail the effectiveness of a new designed more efficient ultrasonic propulsion for large stones and specific stone compositions in a tissue phantom model. In the first clinical trial of noninvasive ultrasonic propulsion, urinary stones of unknown compositions and sizes up to 10 mm were successfully repositioned. MATERIALS AND METHODS The study included 8- to 12-mm stones of 4 different primary compositions (calcium oxalate monohydrate, ammonium acid urate, calcium phosphate, and struvite) and a renal calyx phantom consisting of a 12 mm × 30 mm well in a 10-cm block of tissue-mimicking material. Primary outcome was the number of times a stone was expelled over 10 attempts, with ultrasonic propulsion burst duration varying from 0.5 seconds to 5 seconds. RESULTS Overall success rate at expelling stones was 95%. All calcium oxalate monohydrate and ammonium acid urate stones were expelled 100% of the time. The largest stone (12 mm) became lodged within the 12-mm phantom calyx 25% of the time regardless of the burst duration. With the 0.5-second burst, there was insufficient energy to expel the heaviest stone (0.88 g), but there was sufficient energy at the longer burst durations. CONCLUSION With a single burst, ultrasonic propulsion successfully moved most stones at least 3 cm and, regardless of size or composition, expelled them from the calyx. Ultrasonic propulsion is limited to the stones smaller than the calyceal space, and for each burst duration, related to maximum stone mass. PMID:28964820

Is scoring system of computed tomography based metric parameters can accurately predicts shock wave lithotripsy stone-free rates and aid in the development of treatment strategies?

PubMed Central

Badran, Yasser Ali; Abdelaziz, Alsayed Saad; Shehab, Mohamed Ahmed; Mohamed, Hazem Abdelsabour Dief; Emara, Absel-Aziz Ali; Elnabtity, Ali Mohamed Ali; Ghanem, Maged Mohammed; ELHelaly, Hesham Abdel Azim

2016-01-01

Objective: The objective was to determine the predicting success of shock wave lithotripsy (SWL) using a combination of computed tomography based metric parameters to improve the treatment plan. Patients and Methods: Consecutive 180 patients with symptomatic upper urinary tract calculi 20 mm or less were enrolled in our study underwent extracorporeal SWL were divided into two main groups, according to the stone size, Group A (92 patients with stone ≤10 mm) and Group B (88 patients with stone >10 mm). Both groups were evaluated, according to the skin to stone distance (SSD) and Hounsfield units (≤500, 500–1000 and >1000 HU). Results: Both groups were comparable in baseline data and stone characteristics. About 92.3% of Group A rendered stone-free, whereas 77.2% were stone-free in Group B (P = 0.001). Furthermore, in both group SWL success rates was a significantly higher for stones with lower attenuation <830 HU than with stones >830 HU (P < 0.034). SSD were statistically differences in SWL outcome (P < 0.02). Simultaneous consideration of three parameters stone size, stone attenuation value, and SSD; we found that stone-free rate (SFR) was 100% for stone attenuation value <830 HU for stone <10 mm or >10 mm but total number SWL sessions and shock waves required for the larger stone group were higher than in the smaller group (P < 0.01). Furthermore, SFR was 83.3% and 37.5% for stone <10 mm, mean HU >830, SSD 90 mm and SSD >120 mm, respectively. On the other hand, SFR was 52.6% and 28.57% for stone >10 mm, mean HU >830, SSD <90 mm and SSD >120 mm, respectively. Conclusion: Stone size, stone density (HU), and SSD is simple to calculate and can be reported by radiologists to applying combined score help to augment predictive power of SWL, reduce cost, and improving of treatment strategies. PMID:27141192

Impaction and Prediction: Does Ureteral Wall Thickness Affect the Success of Medical Expulsive Therapy in Pediatric Ureteral Stones?

PubMed

Tuerxun, Aierken; Batuer, Abudukahaer; Erturhan, Sakip; Eryildirim, Bilal; Camur, Emre; Sarica, Kemal

2017-01-01

The study aimed to evaluate the predictive value of ureteral wall thickness (UWT) and stone-related parameters for medical expulsive therapy (MET) success with an alpha blocker in pediatric upper ureteral stones. A total of 35 children receiving MET ureteral stones (<10 mm) were evaluated. Patients were divided into 2 subgroups where MET was successful in 18 children (51.4%) and unsuccessful in 17 children (48.6%). Prior to management, stone size, stone density (in Hounsfield unit), degree of hydronephrosis, and UWT were evaluated with patient demographics and recorded. The possible predictive value of these parameters in success rates and time to stone expulsion were evaluated in a comparative manner between the 2 groups. The overall mean patient age and stone size values were 5.40 ± 0.51 years and 6.24 ± 0.28 mm, respectively. Regarding the predictive values of these parameters for the success of MET, while stone size and UWT were found to be highly predictive for MET success, patients age, body mass index, stone density, and degree of hydronephrosis had no predictive value on this aspect. Our findings indicated that some stone and anatomical factors may be used to predict the success of MET in pediatric ureteral stones in an effective manner. With this approach, unnecessary use of these drugs that may cause a delay in removing the stone will be avoided, and the possible adverse effects of obstruction as well as stone-related clinical symptoms could be minimized. © 2017 S. Karger AG, Basel.

Modular flexible ureteroscopy and holmium laser lithotripsy for the treatment of renal and proximal ureteral calculi: A single-surgeon experience of 382 cases.

PubMed

Yan, Zejun; Xie, Guohai; Yuan, Hesheng; Cheng, Yue

2015-10-01

To determine the safety and efficacy of modular flexible ureteroscopy and holmium laser lithotripsy for the treatment of renal and proximal ureteral calculi, a retrospective chart review of a single surgeon's 3-year modular flexible ureteroscopy experience was performed. All of the patients were treated with modular flexible ureteroscopy and holmium laser lithotripsy by a single surgeon. Stone-free status was defined as no fragments or a single fragment ≤4 mm in diameter at the 3-month follow-up. The procedure number, operative time, stone-free rates, repeat usage of the multilumen catheter, and perioperative complications were documented. The present study included 215 male patients and 167 female patients, with an average age of 48.5±13.7 years (range, 17-84 years). The mean stone size was 11.5±4.1 mm (range, 4-28 mm), and the mean total stone burden was 17.5±5.7 mm (range 15-46 mm). A total of 305 patients (79.8%) had a stone burden ≤20 mm, and 77 patients (20.2%) had a stone burden >20 mm. The mean number of primary procedures was 1.3±0.2 (range, 1-3). The stone-free rate following the first and the second procedure was 73.4 and 86.9%, respectively. The mean postoperative hospital stay was 3.1±1.2 days (range, 2-6 days). The highest clearance rates were observed for proximal ureteral stones (100%) and renal pelvic stones (88.7%), whereas the lowest clearance rates were observed for lower calyx stones (76.7%) and multiple calyx stones (77.8%). The higher the initial stone burden, the lower the postoperative stone-free rate (≤20 vs. >20 mm; 89.8 vs. 75.3%). The overall complication rate was 8.1%. The results of the present study suggest that modular flexible ureteroscopy with holmium laser lithotripsy may be considered the primary method for the treatment of renal and proximal ureteral calculi in select patients, due to its acceptable efficacy, low morbidity, and relatively low maintenance costs.

PROMIS® Pain is Independent of Stone Burden and Predicts Surgical Intervention in Patients with Ureteral Stones.

PubMed

Portis, Jennifer L; Neises, Suzanne M; Portis, Andrew J

2018-04-30

Patients with obstructing ureteral stones typically experience sudden onset, severe pain. We examine the National Institutes of Health's Patient Reported Outcome Measurement Information System (PROMIS®) pain instruments in patients with acute ureteral stones. PROMIS® pain measures were obtained from a complete cohort of patients presenting to a subspecialty kidney stone clinic after discharge from emergency department (ED). Patients were followed longitudinally through course of care. Raw scores were translated into population-normed T-scores (T-score 50 = US pain population mean). Objective and patient-centered factors were evaluated with reference to T-score thresholds for pain intensity (60 = 1 standard deviation (SD) above mean) and pain interference (70 = 2 SD). Multivariable logistic regression in 650 patients demonstrated absence of association between PROMIS® pain scores and stone size or location. Pain scores were associated with age, gender and ED pain scores (p<0.05). Initial stone surgery was predicted by stone size <4mm (0.14, 0.07-0.3 [odds ratio, 95% confidence interval]), >6 mm (19.1, 0.22-39.58), proximal location (1.75, 1.34-2.3), and pain intensity >60 (7.03, 3.63-13.6) but not pain interference (p<0.001). Failure of attempted stone passage was less likely for stone size <4 mm (0.26, 0.14-0.48, p<0.001), and more likely for proximal stone location (1.61, 1.21-2.14, p<0.01) and pain intensity >60 (2.74, 1.23-6.07, p<0.05). PROMIS® pain scores are independent of stone size and location. Attention to ED discharge symptom control offers potential to improve patient care. PROMIS® pain intensity is an independent predictor of surgical intervention for patients with ureteral stones ≤1 cm. Copyright © 2018 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Addition of Sodium Bicarbonate to Irrigation Solution May Assist in Dissolution of Uric Acid Fragments During Ureteroscopy.

PubMed

Paonessa, Jessica E; Williams, James C; Lingeman, James E

2018-04-01

We hypothesized that adding sodium bicarbonate (bicarb) to normal saline (NS) irrigation during ureteroscopy in patients with uric acid (UA) nephrolithiasis may assist in dissolving small stone fragments produced during laser lithotripsy. In vitro testing was performed to determine whether dissolution of UA fragments could be accomplished within 1 hour. In total 100% UA renal calculi were fragmented, filtered, and separated by size. Fragment sizes were <0.5 mm and 0.5 to 1 mm. Similar amounts of stone material were agitated in solution at room temperature. Four solutions were tested (NS, NS +1 ampule bicarb/L, NS +2, NS +3). Both groups were filtered to remove solutions after fixed periods. Filtered specimens were dried and weighed. Fragment dissolution rates were calculated as percent removed per hour. Additional testing was performed to determine whether increasing the temperature of solution affected dissolution rates. For fragments <0.5 mm, adding 2 or 3 bicarb ampules/L NS produced a dissolution rate averaging 91% ± 29% per hour. This rate averaged 226% faster than NS alone. With fragments 0.5 to 1 mm, addition of 2 or 3 bicarb ampules/L NS yielded a dissolution rate averaging 22% ± 7% per hour, which was nearly five times higher than NS alone. There was a trend for an increase in mean dissolution rate with higher temperature but this increase was not significant (p = 0.30). The addition of bicarbonate to NS more than doubles the dissolution rate of UA stone fragments and fragments less than 0.5 mm can be completely dissolved within 1 hour. Addition of bicarb to NS irrigation is a simple and inexpensive approach that may assist in the dissolution of UA fragments produced during ureteroscopic laser lithotripsy. Further studies are needed to determine whether a clinical benefit exists.

Cost Analysis of Flexible Ureteroscope Repairs: Evaluation of 655 Procedures in a Community-Based Practice.

PubMed

Kramolowsky, Eugene; McDowell, Zachary; Moore, Blake; Booth, Brigette; Wood, Nada

2016-03-01

The frequency of flexible ureteroscopy has increased with the introduction of improved instrumentation. Ureteroscopes allow increased endoscopic access to the ureter and kidney. However, maintenance and repair of scopes may increase the total procedure expense. In 3 years (8/2011-7/2014), 655 flexible ureteroscopies were performed at a single-specialty, urology, ambulatory surgery center. Procedures were performed by 26 board-certified urologists using four Olympus URF P5 flexible ureteroscopes. The instruments were handled by a single team and sterilized through the STERIS System E1. Repairs were performed by the manufacturer on an as needed basis. Patient records were reviewed to determine the preoperative diagnosis, operative time, location and size of the stone, and use of laser or ureteral sheath. The occurrence, nature of flexible ureteroscope damage, and cost of repairs were evaluated. Of the ureteroscopies performed, 78% was for the treatment of calculi (50.1% in the kidney). Mean stone size was 8.5 ± 0.2 mm, with larger stones (11 mm) located in the kidney. The flexible ureteroscope was advanced over a guidewire (88% of cases); a laser fiber was introduced in 70%, and a ureteral sheath was used in 13.4%. Mean procedure time was 40 minutes. The most common reasons for ureteroscope repair were cloudy lens (16 repairs) and broken optic fibers (9 repairs). There were 31 repairs during the study period (average 21 cases per repair). Flexible ureteroscopes were out of service for an average of 11 days per repair (range 3-20). The total cost of repairs was $233,150 or ∼$7521 per repair. The average repair cost per flexible ureteroscopy performed was $355. Expenses associated with instrument repair can significantly impact a procedure's net revenue, thus efforts should be made to minimize instrument breakage. The expense of repairing a flexible ureteroscope per procedure can be significant and needs to be considered when pricing this procedure.

Ultrasound vs. Computed Tomography for Severity of Hydronephrosis and Its Importance in Renal Colic.

PubMed

Leo, Megan M; Langlois, Breanne K; Pare, Joseph R; Mitchell, Patricia; Linden, Judith; Nelson, Kerrie P; Amanti, Cristopher; Carmody, Kristin A

2017-06-01

Supporting an "ultrasound-first" approach to evaluating renal colic in the emergency department (ED) remains important for improving patient care and decreasing healthcare costs. Our primary objective was to compare emergency physician (EP) ultrasound to computed tomography (CT) detection of hydronephrosis severity in patients with suspected renal colic. We calculated test characteristics of hydronephrosis on EP-performed ultrasound for detecting ureteral stones or ureteral stone size >5mm. We then analyzed the association of hydronephrosis on EP-performed ultrasound, stone size >5mm, and proximal stone location with 30-day events. This was a prospective observational study of ED patients with suspected renal colic undergoing CT. Subjects had an EP-performed ultrasound evaluating for the severity of hydronephrosis. A chart review and follow-up phone call was performed. We enrolled 302 subjects who had an EP-performed ultrasound. CT and EP ultrasound results were comparable in detecting severity of hydronephrosis ( x 2 =51.7, p<0.001). Hydronephrosis on EP-performed ultrasound was predictive of a ureteral stone on CT (PPV 88%; LR+ 2.91), but lack of hydronephrosis did not rule it out (NPV 65%). Lack of hydronephrosis on EP-performed ultrasound makes larger stone size >5mm less likely (NPV 89%; LR- 0.39). Larger stone size > 5mm was associated with 30-day events (OR 2.30, p=0.03). Using an ultrasound-first approach to detect hydronephrosis may help physicians identify patients with renal colic. The lack of hydronephrosis on ultrasound makes the presence of a larger ureteral stone less likely. Stone size >5mm may be a useful predictor of 30-day events.

Ultrasound vs. Computed Tomography for Severity of Hydronephrosis and Its Importance in Renal Colic

PubMed Central

Leo, Megan M.; Langlois, Breanne K.; Pare, Joseph R.; Mitchell, Patricia; Linden, Judith; Nelson, Kerrie P.; Amanti, Cristopher; Carmody, Kristin A.

2017-01-01

Introduction Supporting an “ultrasound-first” approach to evaluating renal colic in the emergency department (ED) remains important for improving patient care and decreasing healthcare costs. Our primary objective was to compare emergency physician (EP) ultrasound to computed tomography (CT) detection of hydronephrosis severity in patients with suspected renal colic. We calculated test characteristics of hydronephrosis on EP-performed ultrasound for detecting ureteral stones or ureteral stone size >5mm. We then analyzed the association of hydronephrosis on EP-performed ultrasound, stone size >5mm, and proximal stone location with 30-day events. Methods This was a prospective observational study of ED patients with suspected renal colic undergoing CT. Subjects had an EP-performed ultrasound evaluating for the severity of hydronephrosis. A chart review and follow-up phone call was performed. Results We enrolled 302 subjects who had an EP-performed ultrasound. CT and EP ultrasound results were comparable in detecting severity of hydronephrosis (x2=51.7, p<0.001). Hydronephrosis on EP-performed ultrasound was predictive of a ureteral stone on CT (PPV 88%; LR+ 2.91), but lack of hydronephrosis did not rule it out (NPV 65%). Lack of hydronephrosis on EP-performed ultrasound makes larger stone size >5mm less likely (NPV 89%; LR− 0.39). Larger stone size > 5mm was associated with 30-day events (OR 2.30, p=0.03). Conclusion Using an ultrasound-first approach to detect hydronephrosis may help physicians identify patients with renal colic. The lack of hydronephrosis on ultrasound makes the presence of a larger ureteral stone less likely. Stone size >5mm may be a useful predictor of 30-day events. PMID:28611874

Preparation of Water Suspensions of Nanocalcite for Cultural Heritage Applications.

PubMed

Coltelli, Maria-Beatrice; Paolucci, Dario; Castelvetro, Valter; Bianchi, Sabrina; Mascha, Elisabeth; Panariello, Luca; Pesce, Cecilia; Weber, Johannes; Lazzeri, Andrea

2018-04-19

The consolidation of degraded carbonate stone used in ancient monuments is an important topic for European cultural heritage conservation. The products most frequently used as consolidants are based on tetraalkoxy- or alkylalkoxy-silanes (in particular tetraethyl-orthosilicate, TEOS), resulting in the formation of relatively stable amorphous silica or alkylated (hydrophobic) silica inside the stone pores. However, silica is not chemically compatible with carbonate stones; in this respect, nanocalcite may be a suitable alternative. The present work concerns the preparation of water suspensions of calcite nanoparticles (CCNPs) by controlled carbonation of slaked lime using a pilot-scale reactor. A simplified design of experiment was adopted for product optimization. Calcite nanoparticles of narrow size distribution averaging about 30 nm were successfully obtained, the concentration of the interfacial agent and the size of CaO being the most critical parameters. Primary nanoparticle aggregation causing flocculation could be substantially prevented by the addition of polymeric dispersants. Copolymer-based dispersants were produced in situ by controlled heterophase polymerisation mediated by an amphiphilic macro-RAFT (reversible addition-fragmentation transfer) agent. The stabilized CCNP aqueous dispersions were then applied on carbonate and silicate substrates; Scanning Electron Microscopy (SEM)analysis of cross-sections allowed the evaluation of pore penetration, interfacial binding, and bridging (gap-filling) properties of these novel consolidants.

Preparation of Water Suspensions of Nanocalcite for Cultural Heritage Applications

PubMed Central

Coltelli, Maria-Beatrice; Paolucci, Dario; Bianchi, Sabrina; Mascha, Elisabeth; Panariello, Luca; Pesce, Cecilia; Weber, Johannes

2018-01-01

The consolidation of degraded carbonate stone used in ancient monuments is an important topic for European cultural heritage conservation. The products most frequently used as consolidants are based on tetraalkoxy- or alkylalkoxy-silanes (in particular tetraethyl-orthosilicate, TEOS), resulting in the formation of relatively stable amorphous silica or alkylated (hydrophobic) silica inside the stone pores. However, silica is not chemically compatible with carbonate stones; in this respect, nanocalcite may be a suitable alternative. The present work concerns the preparation of water suspensions of calcite nanoparticles (CCNPs) by controlled carbonation of slaked lime using a pilot-scale reactor. A simplified design of experiment was adopted for product optimization. Calcite nanoparticles of narrow size distribution averaging about 30 nm were successfully obtained, the concentration of the interfacial agent and the size of CaO being the most critical parameters. Primary nanoparticle aggregation causing flocculation could be substantially prevented by the addition of polymeric dispersants. Copolymer-based dispersants were produced in situ by controlled heterophase polymerisation mediated by an amphiphilic macro-RAFT (reversible addition-fragmentation transfer) agent. The stabilized CCNP aqueous dispersions were then applied on carbonate and silicate substrates; Scanning Electron Microscopy (SEM)analysis of cross-sections allowed the evaluation of pore penetration, interfacial binding, and bridging (gap-filling) properties of these novel consolidants. PMID:29671800

Measuring stone volume - three-dimensional software reconstruction or an ellipsoid algebra formula?

PubMed

Finch, William; Johnston, Richard; Shaida, Nadeem; Winterbottom, Andrew; Wiseman, Oliver

2014-04-01

To determine the optimal method for assessing stone volume, and thus stone burden, by comparing the accuracy of scalene, oblate, and prolate ellipsoid volume equations with three-dimensional (3D)-reconstructed stone volume. Kidney stone volume may be helpful in predicting treatment outcome for renal stones. While the precise measurement of stone volume by 3D reconstruction can be accomplished using modern computer tomography (CT) scanning software, this technique is not available in all hospitals or with routine acute colic scanning protocols. Therefore, maximum diameters as measured by either X-ray or CT are used in the calculation of stone volume based on a scalene ellipsoid formula, as recommended by the European Association of Urology. In all, 100 stones with both X-ray and CT (1-2-mm slices) were reviewed. Complete and partial staghorn stones were excluded. Stone volume was calculated using software designed to measure tissue density of a certain range within a specified region of interest. Correlation coefficients among all measured outcomes were compared. Stone volumes were analysed to determine the average 'shape' of the stones. The maximum stone diameter on X-ray was 3-25 mm and on CT was 3-36 mm, with a reasonable correlation (r = 0.77). Smaller stones (<9 mm) trended towards prolate ellipsoids ('rugby-ball' shaped), stones of 9-15 mm towards oblate ellipsoids (disc shaped), and stones >15 mm towards scalene ellipsoids. There was no difference in stone shape by location within the kidney. As the average shape of renal stones changes with diameter, no single equation for estimating stone volume can be recommended. As the maximum diameter increases, calculated stone volume becomes less accurate, suggesting that larger stones have more asymmetric shapes. We recommend that research looking at stone clearance rates should use 3D-reconstructed stone volumes when available, followed by prolate, oblate, or scalene ellipsoid formulas depending on the maximum stone diameter. © 2013 The Authors. BJU International © 2013 BJU International.

Appropriate kidney stone size for ureteroscopic lithotripsy: When to switch to a percutaneous approach

PubMed Central

Takazawa, Ryoji; Kitayama, Sachi; Tsujii, Toshihiko

2015-01-01

Flexible ureteroscopy (fURS) has become a more effective and safer treatment for whole upper urinary tract stones. Percutaneous nephrolithotomy (PNL) is currently the first-line recommended treatment for large kidney stones ≥ 20 mm and it has an excellent stone-free rate for large kidney stones. However, its invasiveness is not negligible considering its major complication rates. Staged fURS is a practical treatment for such large kidney stones because fURS has a minimal blood transfusion risk, short hospitalization and few restrictions on daily routines. However, as the stone size becomes larger, the stone-free rate decreases, and the number of operations required increases. Therefore, in our opinion, staged fURS is a practical option for kidney stones 20 to 40 mm. Miniaturized PNL combined with fURS should be considered to be a preferred option for stones larger than 40 mm. Moreover, URS is an effective treatment for multiple upper urinary tract stones. Especially for patients with a stone burden < 20 mm, URS is a favorable option that promises a high stone-free rate after a single session either unilaterally or bilaterally. However, for patients with a stone burden ≥ 20 mm, a staged operation should be considered to achieve stone-free status. PMID:25664253

Kidney pain (image)

MedlinePlus

A kidney stone is a solid piece of material that forms in a kidney. Kidney stones may be the size of sand or ... A kidney stone is a solid piece of material that forms in a kidney. Kidney stones may be the ...

What happens to asymptomatic lower pole kidney stones smaller than 10 mm in children during watchful waiting?

PubMed

Telli, Onur; Hamidi, Nurullah; Bagci, Uygar; Demirbas, Arif; Hascicek, Ahmet Metin; Soygur, Tarkan; Burgu, Berk

2017-05-01

The optimal management of lower pole kidney (LPK) stones in children is controversial. The aim of this study was to determine the outcomes of children with asymptomatic isolated LPK stones smaller than 10 mm during follow-up. A total of 242 patients with 284 stones presenting at our institution between June 2004 and December 2014 with an asymptomatic, single LPK stone with a diameter of <10 mm were enrolled in the study. All children were assigned to receive first-line therapy and then categorized according to the need for medical intervention. Age, gender, stone laterality, stone size and type, associated urinary tract problems, and uncontrolled metabolic status were assessed as predictive factors of medical treatment for small (<10 mm) asymptomatic LPK stones. Stone-free rates were compared between interventions. The mean age and mean stone size were 9.4 ± 1.9 years and 7.4 ± 0.6 mm at admission, respectively. Stone progression rate was 61.2%, and the mean time for intervention was 19.2 ± 4.6 months. Flexible ureterorenoscopy (n = 68) or micro-percutaneous nephrolithotomy (n = 4) were performed for 72 stones (25.4%; group 1), and extracorporeal shock wave lithotripsy was performed for 102 stones (35.9%; group 2). The stone-free rates were 81.8 and 79.3% in group 1 and 2, respectively (p > 0.05). The remaining asymptomatic stones (110, 38.8%; group 3) were managed by continued observation, and at the end of the observation time (mean 40.8 ± 20.8 months) the spontaneous passage rate was 9.1% in this group. In the multivariate analysis, stone size of >7 mm, concurrent renal anomalies, and stones composed of magnesium ammonium phosphate (struvite) and cystine were statistically significant predictors of the need for intervention. Children with stones larger than 7 mm, renal anomalies, or stones composed of metabolically active cystine or struvite are more likely to require intervention, and those with asymptomatic LPK stones smaller than 10 mm can be managed by continued observation.

Noncontrast computed tomography can predict the outcome of shockwave lithotripsy via accurate stone measurement and abdominal fat distribution determination.

PubMed

Geng, Jiun-Hung; Tu, Hung-Pin; Shih, Paul Ming-Chen; Shen, Jung-Tsung; Jang, Mei-Yu; Wu, Wen-Jen; Li, Ching-Chia; Chou, Yii-Her; Juan, Yung-Shun

2015-01-01

Urolithiasis is a common disease of the urinary system. Extracorporeal shockwave lithotripsy (SWL) has become one of the standard treatments for renal and ureteral stones; however, the success rates range widely and failure of stone disintegration may cause additional outlay, alternative procedures, and even complications. We used the data available from noncontrast abdominal computed tomography (NCCT) to evaluate the impact of stone parameters and abdominal fat distribution on calculus-free rates following SWL. We retrospectively reviewed 328 patients who had urinary stones and had undergone SWL from August 2012 to August 2013. All of them received pre-SWL NCCT; 1 month after SWL, radiography was arranged to evaluate the condition of the fragments. These patients were classified into stone-free group and residual stone group. Unenhanced computed tomography variables, including stone attenuation, abdominal fat area, and skin-to-stone distance (SSD) were analyzed. In all, 197 (60%) were classified as stone-free and 132 (40%) as having residual stone. The mean ages were 49.35 ± 13.22 years and 55.32 ± 13.52 years, respectively. On univariate analysis, age, stone size, stone surface area, stone attenuation, SSD, total fat area (TFA), abdominal circumference, serum creatinine, and the severity of hydronephrosis revealed statistical significance between these two groups. From multivariate logistic regression analysis, the independent parameters impacting SWL outcomes were stone size, stone attenuation, TFA, and serum creatinine. [Adjusted odds ratios and (95% confidence intervals): 9.49 (3.72-24.20), 2.25 (1.22-4.14), 2.20 (1.10-4.40), and 2.89 (1.35-6.21) respectively, all p < 0.05]. In the present study, stone size, stone attenuation, TFA and serum creatinine were four independent predictors for stone-free rates after SWL. These findings suggest that pretreatment NCCT may predict the outcomes after SWL. Consequently, we can use these predictors for selecting the optimal treatment for patients with urinary stones. Copyright © 2014. Published by Elsevier Taiwan.

A clinical nomogram to predict the successful shock wave lithotripsy of renal and ureteral calculi.

PubMed

Wiesenthal, Joshua D; Ghiculete, Daniela; Ray, A Andrew; Honey, R John D'A; Pace, Kenneth T

2011-08-01

Although shock wave lithotripsy is dependent on patient and stone related factors, there are few reliable algorithms predictive of its success. In this study we develop a comprehensive nomogram to predict renal and ureteral stone shock wave lithotripsy outcomes. During a 5-year period data from patients treated at our lithotripsy unit were reviewed. Analysis was restricted to patients with a solitary renal or ureteral calculus 20 mm or less. Demographic, stone, patient, treatment and 3-month followup data were collected from a prospective database. All patients were treated using the Philips Lithotron® lithotripter. A total of 422 patients (69.7% male) were analyzed. Mean stone size was 52.3±39.3 mm2 for ureteral stones and 78.9±77.3 mm2 for renal stones, with 95 (43.6%) of the renal stones located in the lower pole. The single treatment success rates for ureteral and renal stones were 60.3% and 70.2%, respectively. On univariate analysis predictors of shock wave lithotripsy success, regardless of stone location, were age (p=0.01), body mass index (p=0.01), stone size (p<0.01), mean stone density (p<0.01) and skin to stone distance (p<0.01). By multivariate logistic regression for renal calculi, age, stone area and skin to stone distance were significant predictors with an AUC of 0.75. For ureteral calculi predictive factors included body mass index and stone size (AUC 0.70). Patient and stone parameters have been identified to create a nomogram that predicts shock wave lithotripsy outcomes using the Lithotron lithotripter, which can facilitate optimal treatment based decisions and provide patients with more accurate single treatment success rates for shock wave lithotripsy tailored to patient specific situations. Copyright © 2011 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Impact of renal anatomy on shock wave lithotripsy outcomes for lower pole kidney stones: results of a prospective multifactorial analysis controlled by computerized tomography.

PubMed

Torricelli, Fabio C M; Marchini, Giovanni S; Yamauchi, Fernando I; Danilovic, Alexandre; Vicentini, Fabio C; Srougi, Miguel; Monga, Manoj; Mazzucchi, Eduardo

2015-06-01

We evaluated which variables impact fragmentation and clearance of lower pole calculi after shock wave lithotripsy. We prospectively evaluated patients undergoing shock wave lithotripsy for a solitary 5 to 20 mm lower pole kidney stone between June 2012 and August 2014. Patient body mass index and abdominal waist circumference were recorded. One radiologist blinded to shock wave lithotripsy outcomes measured stone size, area and density, stone-to-skin distance, infundibular length, width and height, and infundibulopelvic angle based on baseline noncontrast computerized tomography. Fragmentation, success (defined as residual fragments less than 4 mm in asymptomatic patients) and the stone-free rate were evaluated by noncontrast computerized tomography 12 weeks postoperatively. Univariate and multivariate analysis was performed. A total of 100 patients were enrolled in the study. Mean stone size was 9.1 mm. Overall fragmentation, success and stone-free rates were 76%, 54% and 37%, respectively. On logistic regression body mass index (OR 1.27, 95% CI 1.11-1.49, p = 0.004) and stone density (OR 1.0026, 95% CI 1.0008-1.0046, p = 0.005) significantly impacted fragmentation. Stone size (OR 1.24, 95% CI 1.07-1.48, p = 0.039) and stone density (OR 1.0021, 95% CI 1.0007-1.0037, p = 0.012) impacted the success rate while stone size (OR 1.24, 95% CI 1.04-1.50, p = 0.029), stone density (OR 1.0015, 95% CI 1.0001-1.0032, p = 0.046) and infundibular length (OR 1.1035, 95% CI 1.015-1.217, p = 0.015) impacted the stone-free rate. The best outcomes were found in patients with a body mass index of 30 kg/m(2) or less, stones 10 mm or less and 900 HU or less, and an infundibular length of 25 mm or less. The coexistence of significant unfavorable variables led to a stone-free rate of less than 20%. Obese patients with higher than 10 mm density stones (greater than 900 HU) in the lower pole of the kidney with an infundibular length of greater than 25 mm should be discouraged from undergoing shock wave lithotripsy. Copyright © 2015 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Size and location of defects at the coupling interface affect lithotripter performance.

PubMed

Li, Guangyan; Williams, James C; Pishchalnikov, Yuri A; Liu, Ziyue; McAteer, James A

2012-12-01

Study Type--Therapy (case series) Level of Evidence 4. What's known on the subject? and What does the study add? In shock wave lithotripsy air pockets tend to get caught between the therapy head of the lithotripter and the skin of the patient. Defects at the coupling interface hinder the transmission of shock wave energy into the body, reducing the effectiveness of treatment. This in vitro study shows that ineffective coupling not only blocks the transmission of acoustic pulses but also alters the properties of shock waves involved in the mechanisms of stone breakage, with the effect dependent on the size and location of defects at the coupling interface. • To determine how the size and location of coupling defects caught between the therapy head of a lithotripter and the skin of a surrogate patient (i.e. the acoustic window of a test chamber) affect the features of shock waves responsible for stone breakage. • Model defects were placed in the coupling gel between the therapy head of a Dornier Compact-S electromagnetic lithotripter (Dornier MedTech, Kennesaw, GA, USA) and the Mylar (biaxially oriented polyethylene terephthalate) (DuPont Teijin Films, Chester, VA, USA) window of a water-filled coupling test system. • A fibre-optic probe hydrophone was used to measure acoustic pressures and map the lateral dimensions of the focal zone of the lithotripter. • The effect of coupling conditions on stone breakage was assessed using gypsum model stones. • Stone breakage decreased in proportion to the area of the coupling defect; a centrally located defect blocking only 18% of the transmission area reduced stone breakage by an average of almost 30%. • The effect on stone breakage was greater for defects located on-axis and decreased as the defect was moved laterally; an 18% defect located near the periphery of the coupling window (2.0 cm off-axis) reduced stone breakage by only ~15% compared to when coupling was completely unobstructed. • Defects centred within the coupling window acted to narrow the focal width of the lithotripter; an 8.2% defect reduced the focal width ~30% compared to no obstruction (4.4 mm vs 6.5 mm). • Coupling defects located slightly off centre disrupted the symmetry of the acoustic field; an 18% defect positioned 1.0 cm off-axis shifted the focus of maximum positive pressure ~1.0 mm laterally. • Defects on and off-axis imposed a significant reduction in the energy density of shock waves across the focal zone. • In addition to blocking the transmission of shock-wave energy, coupling defects also disrupt the properties of shock waves that play a role in stone breakage, including the focal width of the lithotripter and the symmetry of the acoustic field • The effect is dependent on the size and location of defects, with defects near the centre of the coupling window having the greatest effect. • These data emphasize the importance of eliminating air pockets from the coupling interface, particularly defects located near the centre of the coupling window. © 2012 BJU INTERNATIONAL.

Extracorporeal shockwave lithotripsy: urine cytology findings.

PubMed

Kumar, P V; Salami, K; Tadayyon, A R

2008-12-01

To describe the urine cytology findings before and after stone therapy with extracorporeal shock wave lithotripsy (ESWL) and discuss its importance. The study consisted of 100 patients with a urinary tract stone (79 renal pelvic stones and 21 upper ureteric stones), 74 were male and 26 were female. The ages ranged 30-55 years. The average duration of symptoms was 3-8 years. The size of the stones varied from case to case ranging from 10.2 to 40 mm. Urine samples were obtained on three consecutive days before and after lithotripsy. The smears were stained by the Papanicolaou method. The smears before lithotripsy revealed a few red blood cells, inflammatory cells, epithelial cells and crystals (calcium oxalate, uric acid and triple phosphate). Atypical malignant looking cells and epithelial cell clusters were not noticed. After lithotripsy, the urine samples were examined at different periods, 24 hours, 2 weeks, 1 month, 2 months and 3 months. The smears revealed papillary clusters in all 100 patients within 24 hours and were always associated with inflammation. Atypical malignant looking cells appeared later, within 1-2 months in 21 patients, and were associated with inflammation (19 patients), RBC, crystals and papillary clusters. Most of the papillary clusters and atypical malignant looking cells disappeared before 3 months. The epithelial cell clusters and atypical cells were seen in urine smears after ESWL. Without knowing the previous history these findings can be confused with urothelial neoplasms.

What can the microstructure of stones tell us?

PubMed Central

Williams, James C.; Worcester, Elaine; Lingeman, James E.

2016-01-01

How stones are retained within the kidney while small in size is still not fully understood. In this paper we show two examples of how stones are retained during early growth: One is growth on Randall’s (interstitial) plaque, and the other is growth on mineral that has formed as a luminal plug in a terminal collecting duct. These two mechanisms of stone retention during early growth have distinctive morphologic features that can be seen by methods that show the microscopic structure of the stones. Stones growing on Randall’s plaque display an apatite region that is typically not large in size (less than 0.5 mm across) but which usually shows luminal spaces, which are signs of its origin in the connective tissue of the papilla. Stones growing on ductal plugs also show attachment to a piece of apatite, but the apatite regions are typically larger (often >1 mm long and >0.5 mm wide), and they are solid, without spaces running through them. We propose that knowing the mechanisms of stone retention during early stone formation could allow for better treatment of stone diseases. PMID:27913855

A neural network - based algorithm for predicting stone -free status after ESWL therapy

PubMed Central

Seckiner, Ilker; Seckiner, Serap; Sen, Haluk; Bayrak, Omer; Dogan, Kazım; Erturhan, Sakip

2017-01-01

ABSTRACT Objective: The prototype artificial neural network (ANN) model was developed using data from patients with renal stone, in order to predict stone-free status and to help in planning treatment with Extracorporeal Shock Wave Lithotripsy (ESWL) for kidney stones. Materials and Methods: Data were collected from the 203 patients including gender, single or multiple nature of the stone, location of the stone, infundibulopelvic angle primary or secondary nature of the stone, status of hydronephrosis, stone size after ESWL, age, size, skin to stone distance, stone density and creatinine, for eleven variables. Regression analysis and the ANN method were applied to predict treatment success using the same series of data. Results: Subsequently, patients were divided into three groups by neural network software, in order to implement the ANN: training group (n=139), validation group (n=32), and the test group (n=32). ANN analysis demonstrated that the prediction accuracy of the stone-free rate was 99.25% in the training group, 85.48% in the validation group, and 88.70% in the test group. Conclusions: Successful results were obtained to predict the stone-free rate, with the help of the ANN model designed by using a series of data collected from real patients in whom ESWL was implemented to help in planning treatment for kidney stones. PMID:28727384

Optimizing RNA Extraction of Renal Papilla Biopsy Tissue in Kidney Stone Formers: A New Methodology for Genomic Study.

PubMed

Taguchi, Kazumi; Usawachintachit, Manint; Hamamoto, Shuzo; Unno, Rei; Tzou, David T; Sherer, Benjamin A; Wang, Yongmei; Okada, Atsushi; Stoller, Marshall L; Yasui, Takahiro; Chi, Thomas

2017-09-01

Endoscopic tools have provided versatile examination and treatment for kidney stone procedures. Despite endourologists researching urinary stone disease using endoscopes to collect tissue, this tissue collection method is limited. Endoscopically removed tissues are small in size, restricting the types of genome-based examination possible. We investigated a new method of renal papilla biopsy and RNA extraction to establish a genomic research methodology for kidney stone disease. We conducted a prospective multi-institutional study and collected renal papilla specimens from consecutive percutaneous nephrolithotomy and ureteroscopy (URS) cases performed for removal of upper urinary tract stones. Renal papilla tissue was extracted using ureteroscopic biopsy forceps after stone removal. RNA was extracted using two different extraction kits, and their quantity and quality were examined. Additionally, the impact of biopsy on surgical complications was compared between cases performed with and without biopsy by matched case-control analysis adjusted for age, gender, body mass index, bilaterality, and stone burden. A total of 90 biopsies from 49 patients were performed, and the median duration between specimen collection and RNA extraction was 61 days. Both univariate and multivariate analyses showed BIGopsy ® forceps usage significantly increased the total yield (p = 0.004) and quality (p = 0.001 for A260/280, p = 0.004 for A260/A230) of extracted RNA. Extraction using the RNeasy Micro Kit ® also improved A260/A230, whereas reduced RNA integrity number of extracted RNA by univariate and multivariate analyses (p = 0.002 and p < 0.001, respectively). Moreover, matched case-control study demonstrated that endoscopic renal papilla biopsy caused no significant surgical complications, including bleeding, decreased stone clearance and hematocrit, and renal dysfunction. Biopsies during URS imparted an average of 20 minutes of procedure time over nonbiopsy cases. We demonstrate a safe methodology for optimal RNA extraction of renal papilla tissue. This technique will accelerate advanced genomic studies for kidney stone formers by facilitating larger tissue yields.

Adaptable Design Improvements for Electromagnetic Shock Wave Lithotripters and Techniques for Controlling Cavitation

NASA Astrophysics Data System (ADS)

Smith, Nathan Birchard

In this dissertation work, the aim was to garner better mechanistic understanding of how shock wave lithotripsy (SWL) breaks stones in order to guide design improvements to modern electromagnetic (EM) shock wave lithotripters. To accomplish this goal, experimental studies were carefully designed to isolate mechanisms of fragmentation, and models for wave propagation, fragmentation, and stone motion were developed. In the initial study, a representative EM lithotripter was characterized and tested for in vitro stone comminution efficiency at a variety of field positions and doses using phantom kidney stones of variable physical properties, and in different fluid mediums to isolate the contribution of cavitation. Through parametric analysis of the acoustic field measurements alongside comminution results, a logarithmic correlation was determined between average peak pressure incident on the stone surface and comminution efficiency. It was also noted that for a given stone type, the correlations converged to an average peak pressure threshold for fragmentation, independent of fluid medium in use. The correlation of average peak pressure to efficacy supports the rationale for the acoustic lens modifications, which were pursued to simultaneously enhance beam width and optimize the pulse profile of the lithotripter shock wave (LSW) via in situ pulse superposition for improved stone fragmentation by stress waves and cavitation, respectively. In parallel, a numerical model for wave propagation was used to investigate the variations of critical parameters with changes in lens geometry. A consensus was reached on a new lens design based on high-speed imaging and stone comminution experiments against the original lens at a fixed acoustic energy setting. The results have demonstrated that the new lens has improved efficacy away from the focus, where stones may move due to respiration, fragmentation, acoustic radiation forces, or voluntary patient movements. Using the traditional theory of brittle fragmentation and newfound understanding of average peak pressure correlation to stone comminution, the entire set of stone comminution data for lens comparison was heuristically modeled using a Weibull-style distribution function. This model linked both the average peak pressure and shock wave dose to efficacy, including their respective threshold parameters, and demonstrated correlation of coefficients to cavitation activity. Subsequently, this model was used in prediction of stone comminution efficiency from mimicked respiratory motions in vitro, which compared favorably to actual simulated motion studies using both the new and original lenses. Under a variety of mimicked respiratory motions, the new lens produced statistically higher stone comminution efficiency than the original lens. These results were confirmed in vivo in a swine model, where the new lens produced statistically higher stone comminution after 1,000 and 2,000 shocks. Finally, a mechanistic investigation into the effects of cavitation with the original lens was conducted using an integrated, self-focusing annular ring transducer specially designed for tandem pulse lithotripsy. It was found that cavitation and stone comminution efficiency are progressively enhanced by tandem pulsing as source energies of both the primary LSW and trailing pressure pulse increase, which suggests that cavitation and stress waves act synergistically to enhance the efficacy in kidney stone fragmentation.

"Silent" kidney stones in "asymptomatic" primary hyperparathyroidism-a comparison of multidetector computed tomography and ultrasound.

PubMed

Selberherr, Andreas; Hörmann, Marcus; Prager, Gerhard; Riss, Philipp; Scheuba, Christian; Niederle, Bruno

2017-03-01

The purpose of this study was to demonstrate the high number of kidney stones in primary hyperparathyroidism (PHPT) and the low number of in fact "asymptomatic" patients. Forty patients with PHPT (28 female, 12 male; median age 58 (range 33-80) years; interquartile range 17 years [51-68]) without known symptoms of kidney stones prospectively underwent multidetector computed tomography (MDCT) and ultrasound (US) examinations of the urinary tract prior to parathyroid surgery. Images were evaluated for the presence and absence of stones, as well as for the number of stones and sizes in the long axis. The MDCT and US examinations were interpreted by two experienced radiologists who were blinded to all clinical and biochemical data. Statistical analysis was performed using the Wilcoxon signed-rank test. US revealed a total of 4 kidney stones in 4 (10 %) of 40 patients (median size 6.5 mm, interquartile range 11.5 mm). MDCT showed a total of 41 stones (median size was 3 mm, interquartile range 2.25 mm) in 15 (38 %) of 40 patients. The number of kidney stones detected with MDCT was significantly higher compared to US (p = 0.00124). MDCT is a highly sensitive method for the detection of "silent" kidney stones in patients with PHPT. By widely applying this method, the number of asymptomatic courses of PHPT may be substantially reduced. MDCT should be used primarily to detect kidney stones in PHPT and to exclude asymptomatic PHPT.

Retrograde Ureteroscopic Management of Large Renal Calculi: A Single Institutional Experience and Concise Literature Review.

PubMed

Scotland, Kymora B; Rudnick, Benjamin; Healy, Kelly A; Hubosky, Scott G; Bagley, Demetrius H

2018-06-06

Advances in flexible ureteroscope design and accessory instrumentation have allowed for more challenging cases to be treated ureteroscopically. Here, we evaluate our experience with ureteroscopy (URS) for the management of large renal calculi (≥2 cm) and provide a concise review of recent reports. A retrospective review was undertaken of all URS cases between 2004 and 2014 performed by the endourologic team at a single academic tertiary care institution. We identified patients with at least one stone ≥2 cm managed with retrograde URS. Stone size was defined as the largest linear diameter of the index stone. Small diameter flexible ureteroscopes were used primarily with holmium laser. Patient demographics, intraoperative data, and postoperative outcomes were evaluated. We evaluated 167 consecutive patients who underwent URS for large renal stones ≥2 cm. The initial reason for choosing URS included patient preference (29.5%), failure of other therapies (8.2%), anatomic considerations/body habitus (30.3%), and comorbidities (28.8%). Mean patient age was 55.5 years (22-84). The mean stone size was 2.75 cm with mean number of procedures per patient of 1.65 (1-6). The single session stone-free rate was 57.1%, two-stage procedure stone-free rate was 90.2% and three-stage stone-free rate was 94.0%. Access sheaths were used in 47% of patients. An association was identified between stone size and patient outcomes; smaller stones correlated with decreased number of procedures. Postoperative complications were minor. Single or multi-stage retrograde ureteroscopic lithotripsy is a safe and effective mode of surgical management of large renal calculi. Total stone burden is a reliable predictor of the need for a staged procedure and of stone-free rate.

Is flexible ureterorenoscopy and laser lithotripsy the new gold standard for lower pole renal stones when compared to shock wave lithotripsy: Comparative outcomes from a University hospital over similar time period.

PubMed

Burr, Jacob; Ishii, Hiro; Simmonds, Nick; Somani, Bhaskar K

2015-01-01

Renal lower pole stones pose difficulty in management due to anatomical variation, stone size, hardness and patient demographics. Flexible ureterorenoscopy and laser lithotripsy (FURSL) and shock wave lithotripsy (SWL) are preferred for stones 1-2 cm in size. We wanted to compare the outcomes of FURSL and SWL for lower pole stones during the same time period. All patients who were treated for lower pole stones with FURSL and SWL during a 19-month period were included. The stone free rate (SFR) was defined as ≤3 mm fragments on follow-up imaging or stone free endoscopically. Data was recorded in an excel spreadsheet with SPSS version 21 used for statistical analysis. A total of 161 lower pole procedures were done (93 SWL and 63 FURSL). The mean stone size for SWL (7.4 mm; range: 4-16 mm) was significantly smaller than for FURSL (13.4 mm; 4-53 mm). The mean operating time and hospital stay for FURSL was 65 minutes (range: 30-160 minutes) and 0.5 days (range: 0-7 days) respectively. The SFR was significantly better (p <0.001) for FURSL (n = 63, 93%) compared to SWL (n = 23, 25%). There were 4 (6%) complications (3 Clavien II and 1 Clavien I) in the FURSL group (2 urosepsis, 1 UTI and 1 stent pain). Three patients in the SWL group (Clavien I) were readmitted with renal colic but there were no other complications. FURSL for lower pole stones seems to be a much better alternative than SWL with a high SFR even for larger stones and seems to be the new gold standard for lower pole stone management.

[Analysis of clinical effectiveness and risk factors for complication of percutaneous nephrolototripsia in patients with a solitary kidney].

PubMed

Arustamov, L D; Katibov, M I; Merinov, D S; Gurbanov, Sh Sh; Artemov, A V; Epishov, V A

2017-12-01

Management of patients with large and staghorn stones of a solitary kidney is widely debated among urologists and has not been sufficiently investigated, which determined the relevance of this study. The study comprised 80 patients with large (>20 mm) and staghorn stones of an anatomically or functionally solitary kidney. Of them, 58 patients underwent percutaneous nephrolithotripsy (PNL), and 22 had open surgery. The criterion of the treatment effectiveness was the complete stone clearance or small residual fragments sized less than 3 mm. The safety criterion was the absence of intra- and postoperative complications, according to Clavien-Dindo grading system. The study analyzed the following factors influencing the effectiveness and safety of PNL: the number of accesses; nephroscope diameter; use of a nephroscope sheath; type of lithotripter; size, density, type and composition of the stone. Percutaneous nephrolithotripsy demonstrated statistically significantly better safety results compared with open surgery with comparable effectiveness. Long-term stone recurrence rate after PNL and open surgery was 10.4 and 18.2%, respectively. PNL resulted in a statistically significant improvement in the kidney function while it worsened after open surgery. The effectiveness of PNL depends on the stone type and size and the kind of lithotripter. It was 7.5 times greater for a large stone than for staghorn calculi and 4.6 times higher for stones sized less or equal 45 mm than for those sized > 45 mm. Ultrasonic lithotripter was 2.2 times more effective than another type of lithotripter. The safety of PNL depends on the nephroscope diameter, of a sheath, the number of accesses, the type of lithotripter and the type of stone. Using a 24-Ch nephroscope was 3.6 times safer than that with a diameter greater than 24-Ch; not using a sheath was 3.2 times safer than using it; one access was 3 times safer than at multiple ones; using an ultrasound lithotripter was 2.7 times safer than with another type of lithotripter; treating a large stone was 2.1 times safer than a staghorn stone. The study findings can be used to optimize the treatment of patients with large and staghorn stones of a solitary kidney.

Detection of different kidney stone types: an ex vivo comparison of ultrashort echo time MRI to reference standard CT.

PubMed

Ibrahim, El-Sayed H; Cernigliaro, Joseph G; Pooley, Robert A; Bridges, Mellena D; Giesbrandt, Jamie G; Williams, James C; Haley, William E

2016-01-01

With the development of ultrashort echo time (UTE) sequences, it may now be possible to detect kidney stones by using magnetic resonance imaging (MRI). In this study, kidney stones of varying composition and sizes were imaged using both UTE MRI as well as the reference standard of computed tomography (CT), with different surrounding materials and scan setups. One hundred and fourteen kidney stones were inserted into agarose and urine phantoms and imaged both on a dual-energy CT (DECT) scanner using a standard renal stone imaging protocol and on an MRI scanner using the UTE sequence with both head and body surface coils. A subset of the stones representing all composition types and sizes was then inserted into the collecting system of porcine kidneys and imaged in vitro with both CT and MRI. All of the stones were visible on both CT and MRI imaging. DECT was capable of differentiating between uric acid and nonuric acid stones. In MRI imaging, the choice of coil and large field of view (FOV) did not affect stone detection or image quality. The MRI images showed good visualization of the stones' shapes, and the stones' dimensions measured from MRI were in good agreement with the actual values (R(2)=0.886, 0.895, and 0.81 in the agarose phantom, urine phantom, and pig kidneys, respectively). The measured T2 relaxation times ranged from 4.2 to 7.5ms, but did not show significant differences among different stone composition types. UTE MRI compared favorably with the reference standard CT for imaging stones of different composition types and sizes using body surface coil and large FOV, which suggests potential usefulness of UTE MRI in imaging kidney stones in vivo. Copyright © 2015 Elsevier Inc. All rights reserved.

Does body mass index effect the success of percutaneous nephrolithotomy?

PubMed Central

Şimşek, Abdülmuttalip; Özgör, Faruk; Akbulut, Mehmet Fatih; Küçüktopçu, Onur; Berberoğlu, Ahmet Yalçın; Sarılar, Ömer; Binbay, Murat; Müslümanoğlu, Ahmet Yaser

2014-01-01

Objective: In obese patients, the management of renal calculi presents a number of challenges for urologists. In this study, we aimed to evaluate the efficacy and safety of percutaneous nephrolithotomy (PNL) procedure in obese and morbidly obese patients. Material and methods: We retrospectively reviewed the medical files of 2360 patients treated with PNL between March 2002 and April 2013. The patients were stratified into four groups according to the World Health Organization (WHO) classification of body mass index (BMI): <25 kg/m2 (average), 25–29.9 kg/m2 (overweight), 30–39.9 kg/m2 (obese), and >40 kg/m2 (morbidly obese). Patients under 18 years of age and those with a body mass index under 18 kg/m2 were excluded from the study. Intra-, and postoperative outcomes of PNL were compared between groups. Results: A total of 2102 patients with a mean age of 43±13.62 years were enrolled in the study. The mean stone size, mean number of stones, staghorn stone rate and history of previous shock wave lithotripsy were similar in all groups. The overall stone-free rate was 82 percent. The mean operation time was longer in the morbidly obese group but it was not significantly different from that in the other groups. No differences were observed in hospital stay, complication or stone-free rate among four study groups. Conclusion: Percutaneous nephrolithotomy is a safe and effective treatment for renal stone disease. Body mass index does not affect the success or complication rate in PNL. PMID:26328160

[Solitary stones of the lower renal calyx: how to treat?

PubMed

Martov, A G; Ergakov, D V; Andronov, A S; Dutov, S V; Takhaev, R A; Kil'chukov, Z I; Moskalenko, S A

2017-06-01

The choice of treatment for the stones of the lower renal calyx is one of the challenging issues of modern urology. The aim of this retrospective and prospective study was to investigate the clinical effectiveness and safety of 3 modern minimally invasive techniques for treating renal stones: percutaneous (PNL) and transurethral (TNL) nephrolithotripsy and extracorporeal shock wave lithotripsy (ESWL) in patients with solitary lower calyx stones sized from 10 to 15 mm. The study included 136 patients with symptomatic stones of the lower calyces, who underwent ESWL, PNL and TNL from November 2010 to the present day. The criteria for inclusion in the study were: the presence of a solitary stone of the lower calyx, the stone size of 10 mm to 15 mm, the performance of the classical (standard) PNL in the prone position (puncture access 28-30 Fr) and the follow-up examination at 3 months after the operation. Forty-six patients underwent ESWL, 49 - PNL, and 41 - TNL. Postoperative follow-up was done at 3 months and included a plain radiography, ultrasound and non-contrast-enhanced computed tomography. The stone free rate (SFR) was used as a criterion for the effectiveness of the intervention, where the stone size of 3 mm was taken as the upper limit for the possible presence of fragments. Besides, the rate of repeat interventions, complications and subjective assessment of patients treatment satisfaction (0 to 10) by using visual analogue scale (VAS) were investigated. The effectiveness analysis of the three methods for treating the lower calyx stones sized 10-15 mm showed that PNL was no more effective than TNL (SFR 95.9% and 85.4%, respectively), but both methods were significantly more effective than ESWL (SFR 69.5%). 29.3% of patients who underwent TNL required repeat interventions (TNL or ESWL), while among those treated with ESWL, 45.6% required repeat ESWL sessions. PNL resulted in stone clearance in one stage. Postoperative inflammatory complications were most prevalent among patients who underwent TNL (26.8%). Bleeding requiring hemotransfusion was observed only after PNL (14.3%). Obstructive complications were observed in all study groups. For them, internal stenting was most often performed after ESWL (10.9%), puncture nephrostomy - after TNL (7.3%). Statistically significantly higher VAS measured quality of life was found after ESWL (7.9) and PNL (7.0) compared with THL (4.8). All three methods (PNL, TNL and ESWL) for treating lower calyceal stones sized from 10 to 15 mm are quite effective. Using them separately or in combination allows most patients to safely achieve a stone-free state.

Ultrasonic propulsion of kidney stones.

PubMed

May, Philip C; Bailey, Michael R; Harper, Jonathan D

2016-05-01

Ultrasonic propulsion is a novel technique that uses short bursts of focused ultrasonic pulses to reposition stones transcutaneously within the renal collecting system and ureter. The purpose of this review is to discuss the initial testing of effectiveness and safety, directions for refinement of technique and technology, and opinions on clinical application. Preclinical studies with a range of probes, interfaces, and outputs have demonstrated feasibility and consistent safety of ultrasonic propulsion with room for increased outputs and refinement toward specific applications. Ultrasonic propulsion was used painlessly and without adverse events to reposition stones in 14 of 15 human study participants without restrictions on patient size, stone size, or stone location. The initial feasibility study showed applicability in a range of clinically relevant situations, including facilitating passage of residual fragments following ureteroscopy or shock wave lithotripsy, moving a large stone at the ureteropelvic junction with relief of pain, and differentiating large stones from a collection of small fragments. Ultrasonic propulsion shows promise as an office-based system for transcutaneously repositioning kidney stones. Potential applications include facilitating expulsion of residual fragments following ureteroscopy or shock wave lithotripsy, repositioning stones prior to treatment, and repositioning obstructing ureteropelvic junction stones into the kidney to alleviate acute renal colic.

Ultrasonic propulsion of kidney stones

PubMed Central

May, Philip C.; Bailey, Michael R.; Harper, Jonathan D.

2016-01-01

Purpose of review Ultrasonic propulsion is a novel technique that uses short bursts of focused ultrasonic pulses to reposition stones transcutaneously within the renal collecting system and ureter. The purpose of this review is to discuss the initial testing of effectiveness and safety, directions for refinement of technique and technology, and opinions on clinical application. Recent findings Preclinical studies with a range of probes, interfaces, and outputs have demonstrated feasibility and consistent safety of ultrasonic propulsion with room for increased outputs and refinement toward specific applications. Ultrasonic propulsion was used painlessly and without adverse events to reposition stones in 14 of 15 human study participants without restrictions on patient size, stone size, or stone location. The initial feasibility study showed applicability in a range of clinically relevant situations, including facilitating passage of residual fragments following ureteroscopy or shock wave lithotripsy, moving a large stone at the UPJ with relief of pain, and differentiating large stones from a collection of small fragments. Summary Ultrasonic propulsion shows promise as an office-based system for transcutaneously repositioning kidney stones. Potential applications include facilitating expulsion of residual fragments following ureteroscopy or shock wave lithotripsy, repositioning stones prior to treatment, and repositioning obstructing UPJ stones into the kidney to alleviate acute renal colic. PMID:26845428

Comparison of retrograde intrarenal surgery versus a single-session percutaneous nephrolithotomy for lower-pole stones with a diameter of 15 to 30 mm: A propensity score-matching study.

PubMed

Jung, Gyoo Hwan; Jung, Jae Hyun; Ahn, Tae Sik; Lee, Joong Sub; Cho, Sung Yong; Jeong, Chang Wook; Lee, Seung Bae; Kim, Hyeon Hoe; Oh, Seung-June

2015-07-01

To investigate surgical outcomes between retrograde intrarenal surgery (RIRS) and percutaneous nephrolithotomy (PNL) groups for a main stone sized 15 to 30 mm and located in the lower-pole calyx. Patients who underwent PNL or RIRS for a main stone sized 15 to 30 mm and located in the lower-pole calyx were retrospectively reviewed. Each patient in the RIRS group was matched to one in the PNL group on the basis of calculated propensity scores by use of age, sex, body mass index, previous treatment history, stone site, maximum stone size, and stone volume. We compared perioperative outcomes between the unmatched and matched groups. Patients underwent PNL (n=87, 66.4%) or RIRS (n=44, 33.6%). After matching, 44 patients in each group were included. Mean patient age was 54.4 ± 13.7 years. Perioperative hemoglobin drop was significantly higher and the hospital stay was longer in the PNL group than in the RIRS group. The operative time was significantly longer in the RIRS group than in the PNL group. Stone-free rates were higher and complications rates were lower in the RIRS group than in the PNL group without statistical significance. The presence of a stone located in the lower-anterior minor calyx was a predictor of stone-free status. RIRS and single-session PNL for patients with a main stone of 15 to 30 mm located in the lower-pole calyx showed comparable surgical results. However, RIRS can be performed more safely than PNL with less bleeding. Stones in the lower-anterior minor calyx should be carefully removed during these procedures.

Comparison of retrograde intrarenal surgery versus a single-session percutaneous nephrolithotomy for lower-pole stones with a diameter of 15 to 30 mm: A propensity score-matching study

PubMed Central

Jung, Gyoo Hwan; Jung, Jae Hyun; Ahn, Tae Sik; Lee, Joong Sub; Cho, Sung Yong; Jeong, Chang Wook; Lee, Seung Bae; Kim, Hyeon Hoe

2015-01-01

Purpose To investigate surgical outcomes between retrograde intrarenal surgery (RIRS) and percutaneous nephrolithotomy (PNL) groups for a main stone sized 15 to 30 mm and located in the lower-pole calyx. Materials and Methods Patients who underwent PNL or RIRS for a main stone sized 15 to 30 mm and located in the lower-pole calyx were retrospectively reviewed. Each patient in the RIRS group was matched to one in the PNL group on the basis of calculated propensity scores by use of age, sex, body mass index, previous treatment history, stone site, maximum stone size, and stone volume. We compared perioperative outcomes between the unmatched and matched groups. Results Patients underwent PNL (n=87, 66.4%) or RIRS (n=44, 33.6%). After matching, 44 patients in each group were included. Mean patient age was 54.4±13.7 years. Perioperative hemoglobin drop was significantly higher and the hospital stay was longer in the PNL group than in the RIRS group. The operative time was significantly longer in the RIRS group than in the PNL group. Stone-free rates were higher and complications rates were lower in the RIRS group than in the PNL group without statistical significance. The presence of a stone located in the lower-anterior minor calyx was a predictor of stone-free status. Conclusions RIRS and single-session PNL for patients with a main stone of 15 to 30 mm located in the lower-pole calyx showed comparable surgical results. However, RIRS can be performed more safely than PNL with less bleeding. Stones in the lower-anterior minor calyx should be carefully removed during these procedures. PMID:26175872

The effect of climate variability on urinary stone attacks: increased incidence associated with temperature over 18 °C: a population-based study.

PubMed

Park, Hyoung Keun; Bae, Sang Rak; Kim, Satbyul E; Choi, Woo Suk; Paick, Sung Hyun; Ho, Kim; Kim, Hyeong Gon; Lho, Yong Soo

2015-02-01

The aim of this study was to evaluate the effect of seasonal variation and climate parameters on urinary tract stone attack and investigate whether stone attack is increased sharply at a specific point. Nationwide data of total urinary tract stone attack numbers per month between January 2006 and December 2010 were obtained from the Korean Health Insurance Review and Assessment Service. The effects of climatic factors on monthly urinary stone attack were assessed using auto-regressive integrated moving average (ARIMA) regression method. A total of 1,702,913 stone attack cases were identified. Mean monthly and monthly average daily urinary stone attack cases were 28,382 ± 2,760 and 933 ± 85, respectively. The stone attack showed seasonal trends of sharp incline in June, a peak plateau from July to September, and a sharp decline after September. The correlation analysis showed that ambient temperature (r = 0.557, p < 0.001) and relative humidity (r = 0.513, p < 0.001) were significantly associated with urinary stone attack cases. However, after adjustment for trends and seasonality, ambient temperature was the only climate factor associated with the stone attack cases in ARIMA regression test (p = 0.04). Threshold temperature was estimated as 18.4 °C. Risk of urinary stone attack significantly increases 1.71% (1.02-2.41 %, 95% confidence intervals) with a 1 °C increase of ambient temperature above the threshold point. In conclusion, monthly urinary stone attack cases were changed according to seasonal variation. Among the climates variables, only temperature had consistent association with stone attack and when the temperature is over 18.4 °C, urinary stone attack would be increased sharply.

Significance of lower-pole pelvicaliceal anatomy on stone clearance after shockwave lithotripsy in nonobstructive isolated renal pelvic stones.

PubMed

Sozen, Sinan; Kupeli, Bora; Acar, Cenk; Gurocak, Serhat; Karaoglan, Ustunol; Bozkirli, Ibrahim

2008-05-01

To investigate the probable effect of lower-pole pelvicaliceal anatomy on stone clearance after shockwave lithotripsy (SWL) in patients with nonobstructive renal pelvic stones. The clinical records of patients with isolated renal pelvic stones who underwent SWL between 1996 and 2005 were reviewed. After excluding patients with obstruction leading to dilatation, major anatomic abnormalities, noncalcium stones, metabolic abnormalities, history of recurrent stone disease, multiple stones, and previous renal surgery, 153 patients were enrolled in the study. Lower pole infundibulopelvic angle (IPA) and infundibular length and width were measured from intravenous urography. Patients were classified into three groups according to stone burden (group 1, <100 mm(2); group 2, 101-200 mm(2); group 3, 201-400 mm(2)). The mean stone size was 142.08+/-86.3 mm(2). Overall stone-free rate was 53.6%. Localization of clinically significant or insignificant residual fragments was in the lower calix, renal pelvis, and both in 50 (32.6%), 29 (18.9%), and 8 (5.2%) patients, respectively. There was no statistically significant difference in pelvicaliceal anatomic features except narrower IPA (P=0.02) in group 1 patients with residual stones. The falling of stone fragments to the lower calix in spite of the ureter whether clinically significant or not after SWL of pelvic stones initially seems to be related to stone burden rather than lower caliceal anatomy. However, existence of a more narrow IPA in group 1 patients with residual fragments led us to believe that lower-pole IPA can play a role in stone clearance, especially for smaller stones, probably because of smaller residual fragment size or the more mobile nature of the primary stone.

Investigation into the Effects of Textural Properties on Cuttability Performance of a Chisel Tool

NASA Astrophysics Data System (ADS)

Tumac, Deniz; Copur, Hanifi; Balci, Cemal; Er, Selman; Avunduk, Emre

2018-04-01

The main objective of this study is to investigate the effect of textural properties of stones on cutting performance of a standard chisel tool. Therewithal, the relationships between textural properties and cutting performance parameters and physical and mechanical properties were statistically analyzed. For this purpose, physical and mechanical property tests and mineralogical and petrographic analyses were carried out on eighteen natural stone samples, which can be grouped into three fundamentally different geological origins, i.e., metamorphic, igneous, and sedimentary. Then, texture coefficient analyses were performed on the samples. To determine the cuttability of the stones; the samples were cut with a portable linear cutting machine using a standard chisel tool at different depths of cut in unrelieved (non-interactive) cutting mode. The average and maximum forces (normal and cutting) and specific energy were measured, and the obtained values were correlated with texture coefficient, packing weighting, and grain size. With reference to the relation between depth of cut and cutting performance of the chisel tool for three types of natural stone groups, specific energy decreases with increasing depth of cut, and cutting forces increase in proportion to the depth of cut. The same is observed for the relationship between packing weighting and both of specific energy and cutter forces. On the other hand, specific energy and the forces decrease while grain size increases. Based on the findings of the present study, texture coefficient has strong correlation with specific energy. Generally, the lower depth of cut values in cutting tests shows higher and more reliable correlations with texture coefficient than the increased depth of cut. The results of cutting tests show also that, at a lower depth of cut (less than 1.5 mm), even stronger correlations can be observed between texture coefficient and cutting performance. Experimental studies indicate that cutting performance of chisel tools can be predicted based on texture coefficients of the natural stones.

Field evaluation of support practice (P-factor) for stone walls to control soil erosion in an arid area (Northern Jordan)

NASA Astrophysics Data System (ADS)

Gharaibeh, Mamoun; Albalasmeh, Ammar

2017-04-01

Stone walls have been adopted for long time to control water erosion in many Mediterranean countries. In soil erosion equations, the support practice factor (P-factor) for stone walls has not been fully studied or rarely taken into account especially in semi-arid and arid regions. Field studies were conducted to evaluate the efficiency of traditional stone walls and to quantify soil erosion in six sites in north and northeastern Jordan. Initial estimates using the Universal Soil Loss Equation (USLE) showed that rainfall erosion was reduced by 65% in areas where stone walls are present. Annual soil loss ranged from 5 to 15 t yr-1. The mean annual soil loss in the absence of stone walls ranged from 10-60 t ha-1 with an average value of 35 t ha-1. Interpolating the slope of thickness of A horizon provided an average initial estimate of 0.3 for P value.

Influence of stone content on soil hydraulic properties: experimental investigation and test of existing model concepts

NASA Astrophysics Data System (ADS)

Naseri, Mahyar; Richter, Niels; Iden, Sascha C.; Durner, Wolfgang

2017-04-01

Rock fragments in soil, in this contribution referred to as "stones", play an important role for water flow in the subsurface. To successfully model soil hydraulic processes such as evaporation, redistribution and drainage, an understanding of how stones affect soil hydraulic properties (SHP) is crucial. Past investigations on the role of stones in soil have focused on their influence on the water retention curve (WRC) and on saturated hydraulic conductivity Ks, and have led to some simple theoretical models for the influence of stones on effective SHP. However, studies that measure unsaturated SHP directly, i.e., simultaneously the WRC and hydraulic conductivity curve (HCC) are still missing. Also, studies so far were restricted to low or moderate stone contents of less than 40%. We conducted a laboratory study in which we examined the effect of stone content on effective WRC and HCC of stony soils. Mixtures of soil and stones were generated by substituting background soil with stones in weight fractions between 0% (fine material only) to 100% (pure gravel). Stone sizes were 2-5 mm and 7-15 mm, respectively, and background soils were Sand and Sandy Loam. Packed samples were fully saturated under vacuum and subsequently subjected to evaporation in the laboratory. All experiments were done in three replicates. The soil hydraulic properties were determined by the simplified evaporation method using the UMS HYPROP setup. Questions were whether the applied measurement methodology is applicable to derive the SHP of the mixtures and how the gradual increase of stone content will affect the SHP, particularly the HCC. The applied methodology was successful in identifying effective SHP with a high precision over the full moisture range. WRC and HCC were successfully obtained by HYPROP, even for pure gravel with a size of 7-15 mm. WRCs changed qualitatively in the expected manner, i.e., an increase of stone content reduced porosity and soil water content at all suctions. However, the effect on SHP could not be modelled by assuming stones to be simply impermeable objects that occupy a part of the soil space. This was indicated by a nonlinear increase of the van Genuchten shape parameter α and a decrease of n with increasing gravel content, the latter indicating a widening of the effective pore-size distribution. Saturated conductivity decreased with increasing stone content, but then steeply increased for stone contents > 40%. Unsaturated hydraulic conductivity curves of stone-soil mixtures showed a less pronounced decrease with increasing suction as compared to the pure components, again indicating a widening of the effective pore-size distribution and a nonlinear dependence of the effective unsaturated conductivity on stone content.

Kidney Stones in Children and Teens

MedlinePlus

... Issues Listen Español Text Size Email Print Share Kidney Stones in Children and Teens Page Content Article ... teen girls having the highest incidence. Types of Kidney Stones There are many different types of kidney ...

Quantitative Features of Liver Lesions, Lung Nodules, and Renal Stones at Multi-Detector Row CT Examinations: Dependency on Radiation Dose and Reconstruction Algorithm.

PubMed

Solomon, Justin; Mileto, Achille; Nelson, Rendon C; Roy Choudhury, Kingshuk; Samei, Ehsan

2016-04-01

To determine if radiation dose and reconstruction algorithm affect the computer-based extraction and analysis of quantitative imaging features in lung nodules, liver lesions, and renal stones at multi-detector row computed tomography (CT). Retrospective analysis of data from a prospective, multicenter, HIPAA-compliant, institutional review board-approved clinical trial was performed by extracting 23 quantitative imaging features (size, shape, attenuation, edge sharpness, pixel value distribution, and texture) of lesions on multi-detector row CT images of 20 adult patients (14 men, six women; mean age, 63 years; range, 38-72 years) referred for known or suspected focal liver lesions, lung nodules, or kidney stones. Data were acquired between September 2011 and April 2012. All multi-detector row CT scans were performed at two different radiation dose levels; images were reconstructed with filtered back projection, adaptive statistical iterative reconstruction, and model-based iterative reconstruction (MBIR) algorithms. A linear mixed-effects model was used to assess the effect of radiation dose and reconstruction algorithm on extracted features. Among the 23 imaging features assessed, radiation dose had a significant effect on five, three, and four of the features for liver lesions, lung nodules, and renal stones, respectively (P < .002 for all comparisons). Adaptive statistical iterative reconstruction had a significant effect on three, one, and one of the features for liver lesions, lung nodules, and renal stones, respectively (P < .002 for all comparisons). MBIR reconstruction had a significant effect on nine, 11, and 15 of the features for liver lesions, lung nodules, and renal stones, respectively (P < .002 for all comparisons). Of note, the measured size of lung nodules and renal stones with MBIR was significantly different than those for the other two algorithms (P < .002 for all comparisons). Although lesion texture was significantly affected by the reconstruction algorithm used (average of 3.33 features affected by MBIR throughout lesion types; P < .002, for all comparisons), no significant effect of the radiation dose setting was observed for all but one of the texture features (P = .002-.998). Radiation dose settings and reconstruction algorithms affect the extraction and analysis of quantitative imaging features in lesions at multi-detector row CT.

Controlled cavitation to augment SWL stone comminution: mechanistic insights in vitro.

PubMed

Duryea, Alexander P; Roberts, William W; Cain, Charles A; Hall, Timothy L

2013-02-01

Stone comminution in shock wave lithotripsy (SWL) has been documented to result from mechanical stresses conferred directly to the stone, as well as the activity of cavitational microbubbles. Studies have demonstrated that the presence of this cavitation activity is crucial for stone subdivision; however, its exact role in the comminution process remains somewhat weakly defined, in part because it is difficult to isolate the cavitational component from the shock waves themselves. In this study, we further explored the importance of cavitation in SWL stone comminution through the use of histotripsy ultrasound therapy. Histotripsy was used to target model stones designed to mimic the mid-range tensile fracture strength of naturally occurring cystine calculi with controlled cavitation at strategic time points in the SWL comminution process. All SWL was applied at a peak positive pressure (p+) of 34 MPa and a peak negative pressure (p-) of 8 MPa; a shock rate of 1 Hz was used. Histotripsy pulses had a p- of 33 MPa and were applied at a pulse repetition frequency (PRF) of 100 Hz. Ten model stones were sonicated in vitro with each of five different treatment schemes: A) 10 min of SWL (600 shocks) with 0.7 s of histotripsy interleaved between successive shocks (totaling to 42 000 pulses); B) 10 min of SWL (600 shocks) followed by 10 min of histotripsy applied in 0.7-s bursts (1 burst per second, totaling to 42 000 pulses); C) 10 min of histotripsy applied in 0.7-s bursts (42 000 pulses) followed by 10 min of SWL (600 shocks); D) 10 min of SWL only (600 shocks); E) 10 min of histotripsy only, applied in 0.7-s bursts (42 000 pulses). Following sonication, debris was collected and sieved through 8-, 6-, 4-, and 2-mm filters. It was found that scheme D, SWL only, generated a broad range of fragment sizes, with an average of 14.9 ± 24.1% of the original stone mass remaining > 8 mm. Scheme E, histotripsy only, eroded the surface of stones to tiny particulate debris that was small enough to pass through the finest filter used in this study (<2 mm), leaving behind a single primary stone piece (>8 mm) with mass 85.1 ± 1.6% of the original following truncated sonication. The combination of SWL and histotripsy (schemes A, B, and C) resulted in a shift in the size distribution toward smaller fragments and complete elimination of debris > 8 mm. When histotripsy-controlled cavitation was applied following SWL (B), the increase in exposed stone surface area afforded by shock wave stone subdivision led to enhanced cavitation erosion. When histotripsy-controlled cavitation was applied before SWL (C), it is likely that stone surface defects induced by cavitation erosion provided sites for crack nucleation and accelerated shock wave stone subdivision. Both of these effects are likely at play in the interleaved therapy (A), although shielding of shock waves by remnant histotripsy microbubble nuclei may have limited the efficacy of this scheme. Nevertheless, these results demonstrate the important role played by cavitation in the stone comminution process, and suggest that the application of controlled cavitation at strategic time points can provide an adjunct to traditional SWL therapy.

Large impacted upper ureteral calculi: A comparative study between retrograde ureterolithotripsy and percutaneous antegrade ureterolithotripsy in the modified lateral position

PubMed Central

Moufid, Kamal; Abbaka, Najib; Touiti, Driss; Adermouch, Latifa; Amine, Mohamed; Lezrek, Mohammed

2013-01-01

Context: The treatment for patients with large impacted proximal ureteral stone remains controversial, especially at institutions with limited resources. Aim: The aim of this study is to compare and to evaluate the outcome and complications of two main treatment procedures for impacted proximal ureteral calculi, retrograde ureterolithotripsy (URS), and percutaneous antegrade ureterolithotripsy (Perc-URS). Settings and Design: Our inclusion criteria were solitary, radiopaque calculi, >15 mm in size in a functioning renal unit. Only those patients in whom the attempt at passing a guidewire or catheter beyond the calculus failed were included in this study. Patients and Methods: Between January 2007 and July 2011, a total of 52 patients (13 women and 39 men) with large impacted upper-ureteral calculi >15 mm and meeting the inclusion criteria were selected. Of these, Perc-URS was done in 22 patients (group 1) while retrograde ureteroscopy was performed in 30 patients (group 2). We analyzed operative time, incidence of complications during and after surgery, the number of postoperative recovery days, median total costs associated per patient per procedure, and the stone-free rate immediately after 5 days and after 1 month. Statistical Analysis Used: Bivariate analysis used the Student t-test and the Mann-Whitney test to compare two means and Chi-square and Fisher's exact tests to compare two percentages. The significance level was set at 0.05. Results: The mean age was 42.3 years (range 22-69). The mean stone sizes (mm) were 34 ± 1.2 and 29.3 ± 1.8 mm in group 1 and 2, respectively. In the Perc-URS group, 21 patients (95.45%) had complete calculus clearance through a single tract in one session of percutaneous surgery, whereas in the URS group, only 20 patients (66.7%) had complete stone clearance (P = 0.007). The mean operative time was higher in the Perc-URS group compared to group 2 (66.5 ± 21.7 vs. 52.13 ± 17.3 min, respectively; P = 0.013). Complications encountered in group 1 included transient postoperative fever (2 pts) and simple urine outflow (2 pts). Ten patients (33%) of group 2 experienced failure: Migration to the kidney (3 pts), ureteral perforation (2 pts), tortuosity of the ureter (2 pts), and epithelial polyps (2 patients). Group 1 patients had an average visual analog (VAS) pain score of 47 mm compared with 31 mm in group 2 patients. The mean hospital stay (days) in group 1 was higher than the group 2 (2.27 ± 0.8 vs. 1.67 ± 0.6, respectively; P = 0.01). The mean analgesia requirement for group 1 (paracetamol chlorhydrate + codeine 12 ± 3 g) was significantly more compared with group B (6.8 ± 2 g) (P < 0.01). The difference in average blood loss between the two groups was not statistically significant. Total costs was slightly higher in group 1 but the difference was not statistically significant between the two groups (15000 vs. 13400 MDH respectively; P > 0.05). After 1 month, the stone free-rate remained higher in group 1 (95.5% vs. 66.7%, respectively; P = 0.012). Conclusions: In our series, Perc-URS is a safe and efficient treatment option for proximal ureteral stone, especially when the stone size is superior to 15 mm with the presence of moderate or severe hydronephrosis. PMID:24049373

Prediction of renal crystalline size distributions in space using a PBE analytic model. 1. Effect of microgravity-induced biochemical alterations.

PubMed

Kassemi, Mohammad; Thompson, David

2016-09-01

An analytical Population Balance Equation model is developed and used to assess the risk of critical renal stone formation for astronauts during future space missions. The model uses the renal biochemical profile of the subject as input and predicts the steady-state size distribution of the nucleating, growing, and agglomerating calcium oxalate crystals during their transit through the kidney. The model is verified through comparison with published results of several crystallization experiments. Numerical results indicate that the model is successful in clearly distinguishing between 1-G normal and 1-G recurrent stone-former subjects based solely on their published 24-h urine biochemical profiles. Numerical case studies further show that the predicted renal calculi size distribution for a microgravity astronaut is closer to that of a recurrent stone former on Earth rather than to a normal subject in 1 G. This interestingly implies that the increase in renal stone risk level in microgravity is relatively more significant for a normal person than a stone former. However, numerical predictions still underscore that the stone-former subject carries by far the highest absolute risk of critical stone formation during space travel. Copyright © 2016 the American Physiological Society.

Gallstones and gallbladder cancer-volume and weight of gallstones are associated with gallbladder cancer: a case-control study.

PubMed

Roa, Iván; Ibacache, Gilda; Roa, Juan; Araya, Juan; de Aretxabala, Xabier; Muñoz, Sergio

2006-06-15

Gallstones are considered the most important risk factor for gallbladder cancer. To identify differences in the number, weight, volume, and density of gallstones associated with chronic cholecystitis (CC), gallbladder dysplasia (GD), and gallbladder cancer (GBC). A total of 125 cases were selected, of which 93 had gallstones associated with GBC and 31 had gallstones associated with GD. The controls were those with CC, matched by sex and age. The number, weight, volume, and density of these gallstones were examined in order to determine differences and relative cancer risk. Number: Multiple gallstones were present in over 76% of cases (GBC and GD) and controls (P = ns). The average number of multiple stones was 21 in GBC versus 14 in controls (P < 0.01). Weight: The average weight of the gallstones was 9.6 g in GBC versus 6.0 g in controls (P = 0.0004). The average weight in multiple stones over 10 g had strong association with GBC (P = 0.0006). Volume: The average volume was 11.7 and 6.48 ml in GBC and controls (P = 0.0002). Average volumes of 6, 8, and 10 ml had a relative cancer risk of 5, 7, and 11 times, respectively. Size: No differences were shown between GBC, GD, and controls. The volume of gallstones associated with other risk factors of GBC may be helpful in prioritizing cholecystectomies in symptomatic patients. Copyright 2006 Wiley-Liss, Inc.

Comparison of the efficacy and morbidity of flexible ureterorenoscopy for lower pole stones compared with other renal locations.

PubMed

Jacquemet, Baptiste; Martin, Lucille; Pastori, Julie; Bailly, Vincent; Guichard, Guillaume; Bernardini, Stéphane; Chabannes, Eric; Bittard, Hugues; Kleinclauss, François

2014-10-01

Flexible ureterorenoscopy (f-URS) for lower pole stones (LPS) compared with other renal locations can be challenging because of anatomic and technical considerations. We aimed to compare the stone-free rate (SFR) and surgical complication rate with f-URS for LPS vs other renal locations. We performed a retrospective, single-center study including 371 f-URS for renal stone retrieval performed in our institution between January 2004 and December 2010. Among the 371 procedures included in this analysis, 139 were performed for stones located in a single renal location other than the lower pole (group 1), and 232 for at least one stone located in the lower pole (group 2). We compared the efficacy (SFR) and the morbidity of f-URS between the two groups. The success of the procedure was defined as a complete SFR 6 months after f-URS. Age, sex, history of urolithiasis, body mass index, and preoperative stent placement did not differ between the two groups. No differences in stone characteristics were observed between both groups except stone size under 10 mm that was significantly higher in group 2 (P=0.018). Technical aspects of the procedure did not differ between the groups, except for more frequent use of an access sheath in group 2 (P=0.007). SFR was comparable between groups (P=0.774). The complication rate was similar in both groups, as was the severity of complications. By multivariate analysis, stone size >10 mm (P<0.0001) and multiple stone locations (P=0.001) were associated with f-URS failure, but lower pole location did not impact on SFR. In our study, stone location, in particular LPS, did not have any impact on efficacy and morbidity of f-URS. Only multiple locations and stone size >10 mm seemed to significantly decrease the SFR, without impacting morbidity.

Are We Banging Our Heads Against the Wall? The Effect of Treatment Head Wear on the Outcomes of Extracorporeal Shockwave Lithotripsy.

PubMed

Hoy, Nathan Y; Shapka, Larissa; Rudzinski, Jan; Schuler, Trevor D; Wollin, Timothy A; Bochinski, Derek; De, Shubha K

2016-09-01

The manufacturer for the Storz Modulith SLX-F2 lithotripter recommends treatment head exchange after 1.65 million shocks. However, there is no documentation describing longevity of the treatment head with continued usage. The objective of this study is to determine whether there is a difference in stone fragmentation effectiveness with the treatment head at the beginning versus the end of its treatment life. We conducted a retrospective chart review of 200 patients-50 consecutive patients treated immediately preceding, and following, two separate treatment head exchanges. Primary outcome measures were stone-free rate (no stone), total stone fragmentation (any decrease in size), and fragmentation rate ≤4 mm (decrease in size with largest residual fragment ≤4 mm), based on most recent follow-up imaging post shockwave. There were no baseline characteristic differences between the pre-exchange and postexchange groups with respect to first time lithotripsy for the stone (85% vs. 77%), stone location, preoperative stenting (3% vs. 4%), mean stone density (912 hounsfield units [HU] vs. 840 HU), mean stone size (9.0 mm vs. 8.1 mm), stone location, and mean number of shocks delivered (3105 vs. 3089). Mean time to follow-up was 2.7 weeks in both groups, with most follow-up imaging consisting of a kidney ureter bladder X-ray (87% pre-exchange vs. 85% postexchange). Stone free (34% vs. 27%), total stone fragmentation (76% vs. 76%), fragmentation ≤4 mm (48% vs. 42%), re-treatment rates (38% vs. 51%), and complication rates (6% vs. 7%), were not statistically different between the pre and postexchange groups, respectively. Exchanging the Storz Modulith F2 lithotripter head at the manufacturer recommended 1.65 million shocks does not affect the stone-free or fragmentation rate. If the manufacturer's recommendation for treatment head longevity is based on clinical outcomes, then there is likely room to extend this number without affecting treatment efficacy.

Is flexible ureterorenoscopy and laser lithotripsy the new gold standard for lower pole renal stones when compared to shock wave lithotripsy: Comparative outcomes from a University hospital over similar time period

PubMed Central

Burr, Jacob; Ishii, Hiro; Simmonds, Nick

2015-01-01

Introduction Renal lower pole stones pose difficulty in management due to anatomical variation, stone size, hardness and patient demographics. Flexible ureterorenoscopy and laser lithotripsy (FURSL) and shock wave lithotripsy (SWL) are preferred for stones 1-2 cm in size. We wanted to compare the outcomes of FURSL and SWL for lower pole stones during the same time period. Material and methods All patients who were treated for lower pole stones with FURSL and SWL during a 19-month period were included. The stone free rate (SFR) was defined as ≤3 mm fragments on follow-up imaging or stone free endoscopically. Data was recorded in an excel spreadsheet with SPSS version 21 used for statistical analysis. Results A total of 161 lower pole procedures were done (93 SWL and 63 FURSL). The mean stone size for SWL (7.4 mm; range: 4-16 mm) was significantly smaller than for FURSL (13.4 mm; 4-53 mm). The mean operating time and hospital stay for FURSL was 65 minutes (range: 30-160 minutes) and 0.5 days (range: 0-7 days) respectively. The SFR was significantly better (p <0.001) for FURSL (n = 63, 93%) compared to SWL (n = 23, 25%). There were 4 (6%) complications (3 Clavien II and 1 Clavien I) in the FURSL group (2 urosepsis, 1 UTI and 1 stent pain). Three patients in the SWL group (Clavien I) were readmitted with renal colic but there were no other complications. Conclusions FURSL for lower pole stones seems to be a much better alternative than SWL with a high SFR even for larger stones and seems to be the new gold standard for lower pole stone management. PMID:26251738

Motion artifacts in kidney stone imaging using single-source and dual-source dual-energy CT scanners: a phantom study.

PubMed

Ibrahim, El-Sayed H; Cernigliaro, Joseph G; Pooley, Robert A; Williams, James C; Haley, William E

2015-10-01

Dual-energy computed tomography (DECT) has shown the capability of differentiating uric acid (UA) from non-UA stones with 90-100% accuracy. With the invention of dual-source (DS) scanners, both low- and high-energy images are acquired simultaneously. However, DECT can also be performed by sequential acquisition of both images on single-source (SS) scanners. The objective of this study is to investigate the effects of motion artifacts on stone classification using both SS-DECT and DS-DECT. 114 kidney stones of different types and sizes were imaged on both DS-DECT and SS-DECT scanners with tube voltages of 80 and 140 kVp with and without induced motion. Postprocessing was conducted to create material-specific images from corresponding low- and high-energy images. The dual-energy ratio (DER) and stone material were determined and compared among different scans. For the motionless scans, all stones were correctly classified with SS-DECT, while two cystine stones were misclassified with DS-DECT. When motion was induced, 94% of the stones were misclassified with SS-DECT versus 11% with DS-DECT (P < 0.0001). Stone size was not a factor in stone misclassification under motion. Stone type was not a factor in stone misclassification under motion with SS-DECT, although with DS-DECT, cystine showed higher number of stone misclassification. Motion artifacts could result in stone misclassification in DECT. This effect is more pronounced in SS-DECT versus DS-DECT, especially if stones of different types lie in close proximity to each other. Further, possible misinterpretation of the number of stones (i.e., missing one, or thinking that there are two) in DS-DECT could be a potentially significant problem.

Ability of One-Dimensional Hairsine-Rose Erosion Model to Predict Sediment Transport over a Soil with Significant Surface Stones

NASA Astrophysics Data System (ADS)

Jomaa, S.; Barry, D. A.; Sander, G. C.; Parlange, J.-Y.; Heng, B. C. P.; Tromp-van Meerveld, H. J.

2010-05-01

Surface stones affect erosion rates by reducing raindrop-driven detachment and protecting the original soil against overland flow induced-hydraulic stress. Numerous studies have shown that the effect of surface stones on erosion depends on both the stone characteristics (e.g., size, distribution) and the soil properties. The aim of this study was (i) to quantify how the stone characteristics can affect the total sediment concentration and the concentrations of the individual size classes, (ii) to test if stones affect preferentially a particular size class within the eroded sediment and (iii) to determine whether the 1D Hairsine-Rose (H-R) erosion model can represent the experimental data. A series of laboratory experiments were conducted using the 2 m × 6 m EPFL erosion flume for a high rainfall intensity (60 mm/h) event on a gentle slope (2.2%). The flume was divided into two identical 1-m wide flumes. This separation was done to allow simultaneous replicate experiments. Experiments were conducted with different configurations and scenarios (stone coverage, size and emplacement). Three coverage proportions (20%, 40%, and 70%), two stone diameters (3-4 and 6-7 cm) and two emplacement types (topsoil and partially embedded) were tested. For each experiment, the total sediment concentration, the concentration for the individual size classes, and the flume discharge were measured. Infiltration rates were measured at different depths and locations. A high resolution laser scanner provided details of the surface change due to erosion during the experiments. This technique allowed us to quantify the spatial distribution of eroded soil and to understand better if sediment transport is 1D or rather 2D over the flumes. The one-dimensional Hairsine-Rose (H-R) erosion model was used to fit the integrated data and to provide estimates of the parameters. The ability of the 1D H-R model to predict the measured sediment concentrations in the presence of stones in the soil matrix with different configurations was tested, with reasonable results.

Internal Structure of Kidney Calculi as a Predictor for Shockwave Lithotripsy Success.

PubMed

Christiansen, Frederikke Eichner; Andreassen, Kim Hovgaard; Osther, Susanne Sloth; Osther, Palle Joern Sloth

2016-03-01

The internal structure of renal calculi can be determined on CT using bone windows and may be classified as homogeneous or inhomogeneous with void regions. In vitro studies have shown homogeneous stones to be less responsive to extracorporeal shockwave lithotripsy (SWL). The objective was to evaluate whether the internal morphology of calculi defined by CT bone window influences SWL outcome in vivo. One hundred eleven patients with solitary renal calculi treated with SWL were included. Treatment data were registered prospectively and follow-up data were collected retrospectively. All patients had noncontrast computed tomography (NCCT) performed before SWL and at 3-month follow-up. The stones were categorized as homogeneous or inhomogeneous. At follow-up, the patient's stone status was registered. Stone-free status was defined as no evidence of calculi on NCCT. Treatment was considered successful if the patient was either stone free or had clinically insignificant residual fragments. Using simple logistic regression, the odds for being stone free 3 months post-SWL were significantly reduced in the patients with inhomogeneous stones compared with patients with homogeneous stones (odds ratio 0.43 [95% confidence interval 0.20, 0.92; p < 0.05]). However, when adjusting for stone size by multiple logistic regression, including stone size (area) as a covariate, this difference became insignificant. The internal structure of kidney stones did not predict the outcome of SWL in vivo.

Multimodal treatments of cystine stones: an observational, retrospective single-center analysis of 14 cases.

PubMed

Shim, Myungsun; Park, Hyung Keun

2014-08-01

To document the experiences of a single institution in evaluating the clinical courses and treatment outcomes of patients with cystine stones. The clinical data of 14 patients with cystine stones who were treated at our institution from March 1994 to July 2012 were reviewed. These data included age at first visit, gender, family history, body mass index, presence of a single kidney, stone locations, stone burden, routine urinalysis, and culture. In addition, we also analyzed data on surgery, shock wave lithotripsy, medical treatment, stone recurrence or regrowth, and overall treatment success rates. The mean age of our patients at their first visit was 19.6±5.0 years, and eight patients were males. The median stone burden and mean urine pH before each surgery were 6.5 cm(2) and 6.5±0.9, respectively. Two patients had a family history of cystine stones. Patients underwent surgery an average of 2.7 times. The median interval between surgeries was 27.3 months, and 1 open surgery, 12 percutaneous nephrolithotomies, and 25 ureterorenoscopies were performed. Potassium citrate or sodium bicarbonate was used in nine cases. D-Penicillamine was continuously used in three patients. Patients had an average incidence of 3.2 recurrences or regrowth of stones during the median follow-up period of 60.5 months. Patients with cystine stones have high recurrence or regrowth rates and relatively large stone burdens. Adequate treatment schedules must therefore be established in these cases to prevent possible deterioration of renal function.

Using Helical CT to Predict Stone Fragility in Shock Wave Lithotripsy (SWL)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Williams, James C. Jr.; Zarse, Chad A.; Jackson, Molly E.

2007-04-05

Great variability exists in the response of urinary stones to SWL, and this is true even for stones composed of the same mineral. Efforts have been made to predict stone fragility to shock waves using computed tomography (CT) patient images, but most work to date has focused on the use of stone CT number (i.e., Hounsfield units). This is an easy number to measure on a patient stone, but its value depends on a number of factors, including the relationship of the size of the stone to me resolution (i.e., the slicewidth) of the CT scan. Studies that have shownmore » a relationship between stone CT number and failure in SWL are reviewed, and all are shown to suffer from error due to stone size, which was not accounted for in the use of Hounsfield unit values. Preliminary data are then presented for a study of calcium oxalate monohydrate (COM) stones, in which stone structure-rather than simple CT number values-is shown to correlate with fragility to shock waves. COM stones that were observed to have structure by micro CT (e.g., voids, apatite regions, unusual shapes) broke to completion in about half the number of shock waves required for COM stones that were observed to be homogeneous in structure by CT. This result suggests another direction for the use of CT in predicting success of SWL: the use of CT to view stone structure, rather than simply measuring stone CT number. Viewing stone structure by CT requires the use of different viewing windows than those typically used for examining patient scans, but much research to date indicates that stone structure can be observed in the clinical setting. Future clinical studies will need to be done to verify the relationship between stone structure observed by CT and stone fragility in SWL.« less

Does the Hounsfield unit value determined by computed tomography predict the outcome of percutaneous nephrolithotomy?

PubMed

Gücük, Adnan; Uyetürk, Uğur; Oztürk, Ufuk; Kemahli, Eray; Yildiz, Mevlüt; Metin, Ahmet

2012-07-01

We aimed to evaluate whether the Hounsfield unit (HU) value predicts outcome in percutaneous nephrolithotomy (PCNL). One hundred and seventy-nine patients who had undergone PCNL in our clinics in the last 4 years were included. Demographic and clinical data of the patients and complications, if any, were recorded. The mean age of the patients was 45.3 ± 14.3 years (range 5-82 y), and 111 of them were males (62%). The mean stone size and HU values were found to be 693.1 ± 628.0 (95-4200) mm(2) and 706.3 ± 245.0 (214-1325), respectively. In logistic regression analysis, the size of the stone, the opacity of the stone, and the HU values were found to be independent predictors of the failure of the procedure (P<0.05). A cutoff value of 677.5 was used for the HU in the receiver operating characteristics analysis. Having a HU value under the cutoff value increased the likelihood of procedure failure by 2.65 times, whereas stones residing in the staghorn localization increased failure by 5.68. It was also observed that if the stone's size was 485 mm(2) or more, the chance of failure increased by 1.9, whereas when the stone was nonopaque, failure increased by 6.04 times (P<0.05). There was a positive correlation between hematocrit decrease and a decrease in HU values (P<0.05), but no correlation was observed between the HU values and duration of surgery or fluoroscopy (P>0.05). In addition to the size and location of the stones, the HU value determined in the unenhanced CT scan may be one of the parameters affecting PCNL outcomes. PCNL is a more efficient method in stones with higher HU values. Therefore, the HU values may be a useful tool for the selection of the treatment modality in patients with renal stones.

Quantitative Prediction of Stone Fragility From Routine Dual Energy CT: Ex vivo proof of Feasibility.

PubMed

Ferrero, Andrea; Montoya, Juan C; Vaughan, Lisa E; Huang, Alice E; McKeag, Ian O; Enders, Felicity T; Williams, James C; McCollough, Cynthia H

2016-12-01

Previous studies have demonstrated a qualitative relationship between stone fragility and internal stone morphology. The goal of this study was to quantify morphologic features from dual-energy computed tomography (CT) images and assess their relationship to stone fragility. Thirty-three calcified urinary stones were scanned with micro-CT. Next, they were placed within torso-shaped water phantoms and scanned with the dual-energy CT stone composition protocol in routine use at our institution. Mixed low- and high-energy images were used to measure volume, surface roughness, and 12 metrics describing internal morphology for each stone. The ratios of low- to high-energy CT numbers were also measured. Subsequent to imaging, stone fragility was measured by disintegrating each stone in a controlled ex vivo experiment using an ultrasonic lithotripter and recording the time to comminution. A multivariable linear regression model was developed to predict time to comminution. The average stone volume was 300 mm 3 (range: 134-674 mm 3 ). The average comminution time measured ex vivo was 32 seconds (range: 7-115 seconds). Stone volume, dual-energy CT number ratio, and surface roughness were found to have the best combined predictive ability to estimate comminution time (adjusted R 2  = 0.58). The predictive ability of mixed dual-energy CT images, without use of the dual-energy CT number ratio, to estimate comminution time was slightly inferior, with an adjusted R 2 of 0.54. Dual-energy CT number ratios, volume, and morphologic metrics may provide a method for predicting stone fragility, as measured by time to comminution from ultrasonic lithotripsy. Copyright © 2016 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

Optimal Skin-to-Stone Distance Is a Positive Predictor for Successful Outcomes in Upper Ureter Calculi following Extracorporeal Shock Wave Lithotripsy: A Bayesian Model Averaging Approach

PubMed Central

Cho, Kang Su; Jung, Hae Do; Ham, Won Sik; Chung, Doo Yong; Kang, Yong Jin; Jang, Won Sik; Kwon, Jong Kyou; Choi, Young Deuk; Lee, Joo Yong

2015-01-01

Objectives To investigate whether skin-to-stone distance (SSD), which remains controversial in patients with ureter stones, can be a predicting factor for one session success following extracorporeal shock wave lithotripsy (ESWL) in patients with upper ureter stones. Patients and Methods We retrospectively reviewed the medical records of 1,519 patients who underwent their first ESWL between January 2005 and December 2013. Among these patients, 492 had upper ureter stones that measured 4–20 mm and were eligible for our analyses. Maximal stone length, mean stone density (HU), and SSD were determined on pretreatment non-contrast computed tomography (NCCT). For subgroup analyses, patients were divided into four groups. Group 1 consisted of patients with SSD<25th percentile, group 2 consisted of patients with SSD in the 25th to 50th percentile, group 3 patients had SSD in the 50th to 75th percentile, and group 4 patients had SSD≥75th percentile. Results In analyses of group 2 patients versus others, there were no statistical differences in mean age, stone length and density. However, the one session success rate in group 2 was higher than other groups (77.9% vs. 67.0%; P = 0.032). The multivariate logistic regression model revealed that shorter stone length, lower stone density, and the group 2 SSD were positive predictors for successful outcomes in ESWL. Using the Bayesian model-averaging approach, longer stone length, lower stone density, and group 2 SSD can be also positive predictors for successful outcomes following ESWL. Conclusions Our data indicate that a group 2 SSD of approximately 10 cm is a positive predictor for success following ESWL. PMID:26659086

Quantitative prediction of stone fragility from routine single and dual energy CT: proof of feasibility

PubMed Central

Ferrero, Andrea; Montoya, Juan C.; Vaughan, Lisa E.; Huang, Alice E.; McKeag, Ian O.; Enders, Felicity T.; Williams, James C.; McCollough, Cynthia H.

2016-01-01

Rationale and Objectives Previous studies have demonstrated a qualitative relationship between stone fragility and internal stone morphology. The goal of this study was to quantify morphological features from dual-energy CT images and assess their relationship to stone fragility. Materials and Methods Thirty-three calcified urinary stones were scanned with micro CT. Next, they were placed within torso-shaped water phantoms and scanned with the dual-energy CT stone composition protocol in routine use at our institution. Mixed low-and high-energy images were used to measure volume, surface roughness, and 12 metrics describing internal morphology for each stone. The ratios of low- to high-energy CT numbers were also measured. Subsequent to imaging, stone fragility was measured by disintegrating each stone in a controlled ex vivo experiment using an ultrasonic lithotripter and recording the time to comminution. A multivariable linear regression model was developed to predict time to comminution. Results The average stone volume was 300 mm3 (range 134–674 mm3). The average comminution time measured ex vivo was 32 s (range 7–115 s). Stone volume, dual-energy CT number ratio and surface roughness were found to have the best combined predictive ability to estimate comminution time (adjusted R2= 0.58). The predictive ability of mixed dual-energy CT images, without use of the dual-energy CT number ratio, to estimate comminution time was slightly inferior, with an adjusted R2 of 0.54. Conclusion Dual-energy CT number ratios, volume, and morphological metrics may provide a method for predicting stone fragility, as measured by time to comminution from ultrasonic lithotripsy. PMID:27717761

Stone heterogeneity index as the standard deviation of Hounsfield units: A novel predictor for shock-wave lithotripsy outcomes in ureter calculi

PubMed Central

Lee, Joo Yong; Kim, Jae Heon; Kang, Dong Hyuk; Chung, Doo Yong; Lee, Dae Hun; Do Jung, Hae; Kwon, Jong Kyou; Cho, Kang Su

2016-01-01

We investigated whether stone heterogeneity index (SHI), which a proxy of such variations, was defined as the standard deviation of a Hounsfield unit (HU) on non-contrast computed tomography (NCCT), can be a novel predictor for shock-wave lithotripsy (SWL) outcomes in patients with ureteral stones. Medical records were obtained from the consecutive database of 1,519 patients who underwent the first session of SWL for urinary stones between 2005 and 2013. Ultimately, 604 patients with radiopaque ureteral stones were eligible for this study. Stone related variables including stone size, mean stone density (MSD), skin-to-stone distance, and SHI were obtained on NCCT. Patients were classified into the low and high SHI groups using mean SHI and compared. One-session success rate in the high SHI group was better than in the low SHI group (74.3% vs. 63.9%, P = 0.008). Multivariate logistic regression analyses revealed that smaller stone size (OR 0.889, 95% CI: 0.841–0.937, P < 0.001), lower MSD (OR 0.995, 95% CI: 0.994–0.996, P < 0.001), and higher SHI (OR 1.011, 95% CI: 1.008–1.014, P < 0.001) were independent predictors of one-session success. The radiologic heterogeneity of urinary stones or SHI was an independent predictor for SWL success in patients with ureteral calculi and a useful clinical parameter for stone fragility. PMID:27035621

Stone heterogeneity index as the standard deviation of Hounsfield units: A novel predictor for shock-wave lithotripsy outcomes in ureter calculi.

PubMed

Lee, Joo Yong; Kim, Jae Heon; Kang, Dong Hyuk; Chung, Doo Yong; Lee, Dae Hun; Do Jung, Hae; Kwon, Jong Kyou; Cho, Kang Su

2016-04-01

We investigated whether stone heterogeneity index (SHI), which a proxy of such variations, was defined as the standard deviation of a Hounsfield unit (HU) on non-contrast computed tomography (NCCT), can be a novel predictor for shock-wave lithotripsy (SWL) outcomes in patients with ureteral stones. Medical records were obtained from the consecutive database of 1,519 patients who underwent the first session of SWL for urinary stones between 2005 and 2013. Ultimately, 604 patients with radiopaque ureteral stones were eligible for this study. Stone related variables including stone size, mean stone density (MSD), skin-to-stone distance, and SHI were obtained on NCCT. Patients were classified into the low and high SHI groups using mean SHI and compared. One-session success rate in the high SHI group was better than in the low SHI group (74.3% vs. 63.9%, P = 0.008). Multivariate logistic regression analyses revealed that smaller stone size (OR 0.889, 95% CI: 0.841-0.937, P < 0.001), lower MSD (OR 0.995, 95% CI: 0.994-0.996, P < 0.001), and higher SHI (OR 1.011, 95% CI: 1.008-1.014, P < 0.001) were independent predictors of one-session success. The radiologic heterogeneity of urinary stones or SHI was an independent predictor for SWL success in patients with ureteral calculi and a useful clinical parameter for stone fragility.

The impact of pelvicaliceal anatomy on the success of retrograde intrarenal surgery in patients with lower pole renal stones.

PubMed

Resorlu, Berkan; Oguz, Ural; Resorlu, Eylem Burcu; Oztuna, Derya; Unsal, Ali

2012-01-01

To evaluate the impact of pelvicaliceal anatomy on the success of retrograde intrarenal surgery (RIRS) for lower pole renal stones and determine which of these factors can be used to select patients who will benefit from RIRS. We evaluated 67 patients who underwent RIRS between 2009 and 2010 for isolated lower pole renal stones. The infundibular length (IL), infundibular width (IW), pelvicaliceal height (PCH), and infundibulopelvic angle (IPA) were measured by preoperative intravenous urogram. Success was defined as either complete clearance or clearance with insignificant residual fragments≤3 mm in size at 2-months follow-up. Mean IL was 26.7±7.9 and 28.2±5.3 mm, mean PCH was 20.7±6.6 and 23.2±4.9 mm in stone-free and non-stone-free patients, respectively. These were slightly larger in the non-stone-free group but not statistically significant (P=.140 and P=.072, respectively). Mean IW was 5.8±3.5 and 5.6±2.2 mm in stone-free and non-stone-free patients, respectively, which had no significant impact on the stone-free rate (P=.719). There were significant differences between the groups in terms of stone length (P=.001) and IPA (P=.003). The mean IPA was 49.37±11.83 and 37.61±13.22 mm in stone-free and non-stone-free patients, respectively. In addition to the influence of stone size, lower pole anatomy, especially IPA, has a significant impact on stone clearance for lower pole stones after RIRS. Copyright © 2012 Elsevier Inc. All rights reserved.

Treatment alternatives for urinary system stone disease in preschool aged children: results of 616 cases.

PubMed

Sen, Haluk; Seckiner, Ilker; Bayrak, Omer; Erturhan, Sakip; Demirbağ, Asaf

2015-02-01

The treatment of stone disease is mostly similar in those adult and children. The standard treatment procedures are as follows: extracorporeal shock wave lithotripsy (ESWL), ureterorenoscopy (URS), percutaneous nephrolithotomy (PCNL), and laparoscopic surgery in selected cases. Open surgery (OS) is another option particularly in such cases with anatomic abnormalities of urinary tract. The present study aims to provide comparative results of stone removal procedures in preschool aged patients who were diagnosed with urinary system stone disease. The retrospective data of 616 pediatric preschool patients consulted with urinary system stone disease between January 2009 and July 2013 were evaluated. All patients were evaluated with Kidney-Ureter-Bladder (KUB) Xray and abdomino-pelvic ultrasound. Intravenous pyelography, unenhanced computed tomography (CT), and renal scintigraphy were performed when needed. Patients were categorized according to the procedures as: Group ESWL, Group URS, Group PNL, Group micro-PNL and Group OS. Following the procedures, opaque residual stones were evaluated with KUB Xray, and non-opaque residual stones were evaluated with unenhanced CT. In groups (ESWL, URS, PNL, micro-PNL, OS), the stone-free rate was 68%, 66%, 85%, 100% and 94 %, respectively. The stone analysis were observed as, calcium oxalate in 377 patients (61.2%), uric acid in 106 patients (17.2%), infection stone in 73 patients (11.8 %), and cysteine in 60 patients (9.7%). There was no significant difference in stone analysis between the groups (p > 0.05) (Table). Minimally invasive procedures are frequently preferred in the pediatric age urinary system stone disease. These procedures are ESWL, PCNL, and ureteroscopy [10,11]. Open surgery is reserved only for rare cases [12]. Similarly the current literature, 18 (2.9%) patients had anatomical anomaly and had high complex stone burden were treated with open surgery in our study. ESWL is a preferred treatment method for pediatric urolithiasis patients with a stone size <20 mm, and the rate of stone-free after ESWL ranges between 57 and 92% [13]. In a study showed the effect of stone size on the success rate in ESWL, the success rate was 91% for stones <10 mm, and 75% for stones >10 mm [15]. In the present study, stone-free rate was noted as 68% on 15 mm or lower stone size. PNL is commonly used to treat stone disease in preschool children [18-20]. In the beginning, urologists hesitated to use instruments suited for adults in case of pediatric kidneys. While some authors accept a cut-off value of 24 F for tract dilatation in the pediatric age, Desai et al. recommended a threshold value <22 F [19,21]. In our study, we used adult PNL instruments in the early period, whereas mini-PERC was performed in the later years. The success rate in PNL group was found as 85%. In recent years, the micro-PNL procedure has been developed to reduce/prevent the complications of standard PNL. In our study, the success rate was calculated as 100% with micro-PNL. This study has certain limitations. The major limitation of our study is its retrospective nature. In addition, sample size of micro-PNL group is fewer than other groups. The goal of kidney stone treatment is to achieve minimal kidney damage and a high success rate. Thus, the procedures are important in the pediatric age group where life expectancy is high, and particularly in the preschool age group. Copyright © 2015 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

Ureteral wall thickness at the impacted ureteral stone site: a critical predictor for success rates after SWL.

PubMed

Sarica, Kemal; Kafkasli, Alper; Yazici, Özgür; Çetinel, Ali Cihangir; Demirkol, Mehmet Kutlu; Tuncer, Murat; Şahin, Cahit; Eryildirim, Bilal

2015-02-01

The aim of the study was to determine the possible predictive value of certain patient- and stone-related factors on the stone-free rates and auxiliary procedures after extracorporeal shock wave lithotripsy in patients with impacted proximal ureteral calculi. A total of 111 patients (86 male, 25 females M/F: 3.44/1) with impacted proximal ureteral stones treated with shock wave lithotripsy were evaluated. Cases were retrieved from a departmental shock wave lithotripsy database. Variables analyzed included BMI of the case, diameter of proximal ureter and renal pelvis, stone size and Hounsfield unit, ureteral wall thickness at the impacted stone site. Stone-free status on follow-up imaging at 3 months was considered a successful outcome. All patients had a single impacted proximal ureteral stone. While the mean age of the cases was 46 ± 13 years (range 26-79 years), mean stone size was 8.95 mm (5.3-15.1 mm). Following shock wave lithotripsy although 87 patients (78.4%) were completely stone-free at 3-month follow-up visit, 24 (21.6%) cases had residual fragments requiring further repeat procedures. Prediction of the final outcome of SWL in patients with impacted proximal ureteral stones is a challenging issue and our data did clearly indicate a highly significant relationship between ureteral wall thickness and the success rates of shock wave lithotripsy particularly in cases requiring additional procedures. Of all the evaluated stone- and patient-related factors, only ureteral wall thickness at the impacted stone site independently predicted shock wave lithotripsy success.

Intrarenal Surgery vs Percutaneous Nephrolithotomy in the Management of Lower Pole Stones Greater than 2 cm.

PubMed

Koyuncu, Hakan; Yencilek, Faruk; Kalkan, Mehmet; Bastug, Yavuz; Yencilek, Esin; Ozdemir, Ahmet Tunc

2015-01-01

To compare the efficacy of RIRS and PNL in lower pole stones ≥ 2 cm. Materials and and Methods: A total of 109 patients who underwent PNL or RIRS for solitary lower pole stone between April 2009 and December 2012, were retrospectively analyzed. Lower pole stone was diagnosed with CT scan. Stone size was assessed as the longest axis of the stone. All patients were informed about the advantages, disadvantages and probable complications of both PNL and RIRS before the selection of the procedure. Patients decided the surgery type by themselves without being under any influences and written informed consent was obtained from all patients prior to the surgery. Patients were divided into two groups according to the patients' preference of surgery type. Group 1 consisted of 77 patients who underwent PNL and Group 2 consisted of 32 patients treated with RIRS. Stone free statuses, postoperative complications, operative time and hospitalization time were compared in both groups. There was no statistical significance between the two groups in mean age, stone size, stone laterality, mean follow-up periods and mean operative times. In PNL group, stone-free rate was 96.1% at first session and 100% after the additional procedure. In Group 2, stone-free rate was 90.6% at the first procedure and 100% after the additional procedure. The final stone-free rates and operative times were similar in both groups. RIRS should be an effective treatment alternative to PNL in lower pole stones larger than 2 cm, especially in selected patients.

Intrarenal Surgery vs Percutaneous Nephrolithotomy in the Management of Lower Pole Stones Greater than 2 cm

PubMed Central

Koyuncu, Hakan; Yencilek, Faruk; Kalkan, Mehmet; Bastug, Yavuz; Yencilek, Esin; Ozdemir, Ahmet Tunc

2015-01-01

Purpose To compare the efficacy of RIRS and PNL in lower pole stones ≥2 cm. Materials and and Methods: A total of 109 patients who underwent PNL or RIRS for solitary lower pole stone between April 2009 and December 2012, were retrospectively analyzed. Lower pole stone was diagnosed with CT scan. Stone size was assessed as the longest axis of the stone. All patients were informed about the advantages, disadvantages and probable complications of both PNL and RIRS before the selection of the procedure. Patients decided the surgery type by themselves without being under any influences and written informed consent was obtained from all patients prior to the surgery. Patients were divided into two groups according to the patients’ preference of surgery type. Group 1 consisted of 77 patients who underwent PNL and Group 2 consisted of 32 patients treated with RIRS. Stone free statuses, postoperative complications, operative time and hospitalization time were compared in both groups. Results There was no statistical significance between the two groups in mean age, stone size, stone laterality, mean follow-up periods and mean operative times. In PNL group, stone-free rate was 96.1% at first session and 100% after the additional procedure. In Group 2, stone-free rate was 90.6% at the first procedure and 100% after the additional procedure. The final stone-free rates and operative times were similar in both groups. Conclusions RIRS should be an effective treatment alternative to PNL in lower pole stones larger than 2 cm, especially in selected patients. PMID:26005965

The incidence and clinical features of acute kidney injury secondary to ureteral calculi.

PubMed

Wang, Si-Jun; Mu, Xiao-Nan; Zhang, Long-Yang; Liu, Qing-Yong; Jin, Xun-Bo

2012-08-01

The aim of this study is to evaluate the incidence and clinical features of acute kidney injury (AKI) secondary to ureteral calculi. Between February 2002 and December 2009, the prevalence of AKI was 0.72% in our series of 2,073 cases of ureteral stones. The AKI patients received ureteroscopy or percutaneous nephrostomy as the primary treatment. The most popular symptom was significant decrease in urine output (75%, 12/16). Five cases (33.3%) were caused by bilateral ureteral stones, and 76.19% of the stones were located in the upper ureter, the mean size of single stone was 1.35 ± 0.38 cm. The serum creatinine before treatment was 514.34 ± 267.04 μmol/L and the blood urea nitrogen before treatment was 21.31 ± 10.24 mmol/L. 46.67% of the patients had a functional or anatomical solitary kidney unit. Our study suggests that risk factors for developing AKI in ureteral stone patients are bigger sized stones, ureteral stones in patients with only one functioning kidney or pre-existing kidney disease, and bilateral ureteral stones. Early effective drainage in these cases could decrease the risk developing AKI secondary to ureteral calculi.

Duct Diameter and Size of Stones Predict Successful Extracorporeal Shock Wave Lithotripsy and Endoscopic Clearance in Patients With Chronic Pancreatitis and Pancreaticolithiasis.

PubMed

Lapp, Robert T; Wolf, J Stuart; Faerber, Gary J; Roberts, William W; McCarthy, Sean T; Anderson, Michelle A; Wamsteker, Erik-Jan; Elta, Grace H; Scheiman, James M; Kwon, Richard S

2016-09-01

The need for endoscopic therapy before extracorporeal shock wave lithotripsy (SWL) to facilitate pancreatic duct stone removal is unclear. Predictive factors associated with successful fragmentation and subsequent complete duct clearance are variable. We hypothesize pancreatic duct strictures and large stones, but not pre-SWL endotherapy, correlate with successful fragmentation and complete duct clearance. A retrospective cohort study of patients with pancreaticolithiasis who underwent SWL and endoscopic retrograde cholangiopancreatography between January 2009 and June 2014 was evaluated. Thirty-seven patients were treated. Technical success (TS) of fragmentation was achieved in 22 patients (60%). Technical success was associated with fewer stones and SWL sessions and smaller stone and duct size. By multivariate logistic regression, only duct dilation was associated with TS. Endoscopic success of complete duct clearance was achieved in 29 patients (80%). Endoscopic success was more frequent with stones 12 mm or less and with successful TS. By multivariate logistic regression, stones greater than 12 mm were associated with endoscopic failure. Pre-SWL endotherapy does not affect stone fragmentation. Patients with a dilated duct (>8 mm) and pancreatic stones 12 mm or greater were associated with unsuccessful TS and endoscopic success, respectively, and may benefit from early referral for surgical decompression.

Stenting or not prior to extracorporeal shockwave lithotripsy for ureteral stones? Results of a prospective randomized study.

PubMed

Sfoungaristos, Stavros; Polimeros, Nikolaos; Kavouras, Adamantios; Perimenis, Petros

2012-06-01

To determine the need for pre-treatment stenting in patients undergoing extracorporeal shockwave lithotripsy (ESWL) for ureteral stones sized 4-10 mm. A prospective randomized study was conducted between September 2009 and March 2011. Included 156 patients randomized in stented and non-stented groups and underwent a maximum of 3 ESWL sessions. Radiographic follow-up was used to assess the stone fragmentation and clearance. Results were compared in terms of stone-free rates, post-treatment morbidity and complications. Overall efficacy was 76.9%. Stone-free rates were statistically significantly lower (P = 0.026) in the stented group (68.6%) compared to the non-stented ones (83.7%). Furthermore, stenting was significantly correlated with post-treatment lower urinary tract symptoms (P ≤ 0.001), need for more ESWL sessions (P = 0.019) and possibility for operation due to ESWL failure (P = 0.026). A multivariate analysis was conducted to identify the parameters which may predict complete stone removal after ESWL. Stone size (P = 0.026), stone location (P = 0.011) and stenting (P = 0.007) were the most significant factors. ESWL is an efficient and safe treatment for 4- to 10-mm ureteral stones. Pre-treatment stenting is limiting stone-free rates and is significantly influencing post-ESWL morbidity and quality of life in a negative manner, while it contributes minimally to the prophylaxis of complications.

Enhanced High-Rate Shockwave Lithotripsy Stone Comminution in an In Vivo Porcine Model Using Acoustic Bubble Coalescence.

PubMed

Alavi Tamaddoni, Hedieh; Roberts, William W; Duryea, Alexander P; Cain, Charles A; Hall, Timothy L

2016-12-01

Cavitation plays a significant role in the efficacy of stone comminution during shockwave lithotripsy (SWL). Although cavitation on the surface of urinary stones helps to improve fragmentation, cavitation bubbles along the propagation path may shield or block subsequent shockwaves (SWs) and potentially induce collateral tissue damage. Previous in vitro work has shown that applying low-amplitude acoustic waves after each SW can force bubbles to consolidate and enhance SWL efficacy. In this study, the feasibility of applying acoustic bubble coalescence (ABC) in vivo was tested. Model stones were percutaneously implanted and treated with 2500 lithotripsy SWs at 120 SW/minute with or without ABC. Comparing the results of stone comminution, a significant improvement was observed in the stone fragmentation process when ABC was used. Without ABC, only 25% of the mass of the stone was fragmented to particles <2 mm in size. With ABC, 75% of the mass was fragmented to particles <2 mm in size. These results suggest that ABC can reduce the shielding effect of residual bubble nuclei, resulting in a more efficient SWL treatment.

The material from Lampung as coarse aggregate to substitute andesite for concrete-making

NASA Astrophysics Data System (ADS)

Amin, M.; Supriyatna, Y. I.; Sumardi, S.

2018-01-01

Andesite stone is usually used for split stone material in the concrete making. However, its availability is decreasing. Lampung province has natural resources that can be used for coarse aggregate materials to substitute andesite stone. These natural materials include limestone, feldspar stone, basalt, granite, and slags from iron processing waste. Therefore, a research on optimizing natural materials in Lampung to substitute andesite stone for concrete making is required. This research used laboratory experiment method. The research activities included making cubical object samples of 150 x 150 x 150 mm with material composition referring to a standard of K.200 and w/c 0.61. Concrete making by using varying types of aggregates (basalt, limestone, slag) and aggregate sizes (A = 5-15 mm, B = 15-25 mm, and 25-50 mm) was followed by compressive strength test. The results showed that the obtained optimal compressive strengths for basalt were 24.47 MPa for 50-150 mm aggregate sizes, 21.2 MPa for 15-25 mm aggregate sizes, and 20.7 MPa for 25-50 mm aggregate sizes. These results of basalt compressive strength values were higher than the same result for andesite (19.69 MPa for 50-150 mm aggregate sizes), slag (22.72 MPa for 50-150 mm aggregate sizes), and limestone (19.69 Mpa for 50-150 mm aggregate sizes). These results indicated that basalt, limestone, and slag aggregates were good enough to substitute andesite as materials for concrete making. Therefore, natural resources in Lampung can be optimized as construction materials in concrete making.

Efficacy and safety of Ho:YAG laser lithotripsy for ureteroscopic removal of proximal and distal ureteral calculi.

PubMed

Khoder, Wael Y; Bader, Markus; Sroka, Ronald; Stief, Christian; Waidelich, Raphaela

2014-08-08

Laser lithotripsy is an established endourological modality. Ho:YAG laser have broadened the indications for ureteroscopic stone managements to include larger stone sizes throughout the whole upper urinary tract. Aim of current work is to assess efficacy and safety of Ho:YAG laser lithotripsy during retrograde ureteroscopic management of ureteral calculi in different locations. 88 patients were treated with ureteroscopic Ho:YAG laser lithotripsy in our institute. Study endpoint was the number of treatments until the patient was stone-free. Patients were classified according to the location of their stones as Group I (distal ureteric stones, 51 patients) and group II (proximal ureteral stones, 37). Group I patients have larger stones as Group II (10.70 mm vs. 8.24 mm, respectively, P = 0.020). Overall stone free rate for both groups was 95.8%. The mean number of procedures for proximal calculi was 1.1 ± 0.1 (1-3) and for distal calculi was 1.0 ± 0.0. The initial treatment was more successful in patients with distal ureteral calculi (100% vs. 82.40%, respectively, P = 0.008). No significant difference in the stone free rate was noticed after the second laser procedure for stones smaller versus larger than 10 mm (100% versus 94.1%, P = 0.13). Overall complication rate was 7.9% (Clavien II und IIIb). Overall and grade-adjusted complication rates were not dependent on the stone location. No laser induced complications were noticed. The use of the Ho:YAG laser appears to be an adequate tool to disintegrate ureteral calculi independent of primary location. Combination of the semirigid and flexible ureteroscopes as well as the appropriate endourologic tools could likely improve the stone clearance rates for proximal calculi regardless of stone-size.

Salivary stones: symptoms, aetiology, biochemical composition and treatment.

PubMed

Kraaij, S; Karagozoglu, K H; Forouzanfar, T; Veerman, E C I; Brand, H S

2014-12-05

Salivary stones, also known as sialoliths, are calcified concrements in the salivary glands. Sialoliths are more frequently located in the submandibular gland (84%), than in the parotid gland (13%). The majority of the submandibular stones are located in Wharton's duct (90%), whereas parotid stones are more often located in the gland itself. Salivary stones consist of an amorphous mineralised nucleus, surrounded by concentric laminated layers of organic and inorganic substances. The organic components of salivary stones include collagen, glycoproteins, amino acids and carbohydrates. The major inorganic components are hydroxyapatite, carbonate apatite, whitlockite and brushite. The management of salivary stones is focused on removing the salivary stones and preservation of salivary gland function which depends on the size and location of the stone. Conservative management of salivary stones consists of salivary gland massage and the use of sialogogues. Other therapeutic options include removal of the stone or in some cases surgical removal of the whole salivary gland.

Correlation of gravestone decay and air quality 1960-2010

NASA Astrophysics Data System (ADS)

Mooers, H. D.; Carlson, M. J.; Harrison, R. M.; Inkpen, R. J.; Loeffler, S.

2017-03-01

Evaluation of spatial and temporal variability in surface recession of lead-lettered Carrara marble gravestones provides a quantitative measure of acid flux to the stone surfaces and is closely related to local land use and air quality. Correlation of stone decay, land use, and air quality for the period after 1960 when reliable estimates of atmospheric pollution are available is evaluated. Gravestone decay and SO2 measurements are interpolated spatially using deterministic and geostatistical techniques. A general lack of spatial correlation was identified and therefore a land-use-based technique for correlation of stone decay and air quality is employed. Decadally averaged stone decay is highly correlated with land use averaged spatially over an optimum radius of ≈7 km even though air quality, determined by records from the UK monitoring network, is not highly correlated with gravestone decay. The relationships among stone decay, air-quality, and land use is complicated by the relatively low spatial density of both gravestone decay and air quality data and the fact that air quality data is available only as annual averages and therefore seasonal dependence cannot be evaluated. However, acid deposition calculated from gravestone decay suggests that the deposition efficiency of SO2 has increased appreciably since 1980 indicating an increase in the SO2 oxidation process possibly related to reactions with ammonia.

X-ray diffraction and SEM study of kidney stones in Israel: quantitative analysis, crystallite size determination, and statistical characterization.

PubMed

Uvarov, Vladimir; Popov, Inna; Shapur, Nandakishore; Abdin, Tamer; Gofrit, Ofer N; Pode, Dov; Duvdevani, Mordechai

2011-12-01

Urinary calculi have been recognized as one of the most painful medical disorders. Tenable knowledge of the phase composition of the stones is very important to elucidate an underlying etiology of the stone disease. We report here the results of quantitative X-ray diffraction phase analysis performed on 278 kidney stones from the 275 patients treated at the Department of Urology of Hadassah Hebrew University Hospital (Jerusalem, Israel). Quantification of biominerals in multicomponent samples was performed using the normalized reference intensity ratio method. According to the observed phase compositions, all the tested stones were classified into five chemical groups: oxalates (43.2%), phosphates (7.7%), urates (10.3%), cystines (2.9%), and stones composed of a mixture of different minerals (35.9%). A detailed analysis of each allocated chemical group is presented along with the crystallite size calculations for all the observed crystalline phases. The obtained results have been compared with the published data originated from different geographical regions. Morphology and spatial distribution of the phases identified in the kidney stones were studied with scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). This type of detailed study of phase composition and structural characteristics of the kidney stones was performed in Israel for the first time.

Data Package for Secondary Waste Form Down-Selection—Cast Stone

DOE Office of Scientific and Technical Information (OSTI.GOV)

Serne, R. Jeffrey; Westsik, Joseph H.

2011-09-05

Available literature on Cast Stone and Saltstone was reviewed with an emphasis on determining how Cast Stone and related grout waste forms performed in relationship to various criteria that will be used to decide whether a specific type of waste form meets acceptance criteria for disposal in the Integrated Disposal Facility (IDF) at Hanford. After the critical review of the Cast Stone/Saltstone literature, we conclude that Cast Stone is a good candidate waste form for further consideration. Cast stone meets the target IDF acceptance criteria for compressive strength, no free liquids, TCLP leachate are below the UTS permissible concentrations andmore » leach rates for Na and Tc-99 are suiteably low. The cost of starting ingredients and equipment necessary to generate Cast Stone waste forms with secondary waste streams are low and the Cast Stone dry blend formulation can be tailored to accommodate variations in liquid waste stream compositions. The database for Cast Stone short-term performance is quite extensive compared to the other three candidate waste solidification processes. The solidification of liquid wastes in Cast Stone is a mature process in comparison to the other three candidates. Successful production of Cast Stone or Saltstone has been demonstrated from lab-scale monoliths with volumes of cm3 through m3 sized blocks to 210-liter sized drums all the way to the large pours into vaults at Savannah River. To date over 9 million gallons of low activity liquid waste has been solidified and disposed in concrete vaults at Savannah River.« less

Dual-energy dual-source CT with additional spectral filtration can improve the differentiation of non-uric acid renal stones: An ex vivo phantom study

PubMed Central

Qu, Mingliang; Ramirez Giraldo, Juan C.; Leng, Shuai; Williams, James C.; Vrtiska, Terri J.; Lieske, John C.; McCollough, Cynthia H.

2014-01-01

Purpose To determine the ex vivo ability of dual-energy, dual-source computed tomography (DE-DSCT) with additional tin filtration to differentiate between five groups of human renal stone types. Methods Forty-three renal stones of ten types were categorized into five primary groups based on effective atomic numbers, which were calculated as the weighted average of the atomic numbers of constituent atoms. Stones were embedded in porcine kidneys and placed in a 35cm water phantom. DE-DSCT scans were performed with and without tin filtration at 80/140kV. The CT number ratio [CTR=CT(low)/CT(high)] was calculated on a volumetric voxel-by-voxel basis for each stone. Statistical analysis was performed and receiver operating characteristic (ROC) curves were plotted to compare the difference in CTR with and without tin filtration, and to measure the discrimination between stone groups. Results CTR of non-uric acid stones increased on average by 0.17 (range 0.03–0.36) with tin filtration. The CTR values for non-uric acid stone groups were not significantly different (p>0.05) between any of the two adjacent groups without tin filtration. Use of the additional tin filtration on the high-energy x-ray tube significantly improved the separation of non-uric acid stone types by CTR (p<0.05). The area under the ROC curve increased from 0.78–0.84 without fin filtration to 0.89–0.95 with tin filtration. Conclusion Our results demonstrated better separation between different stone types when additional tin filtration was used on DE-DSCT. The increased spectral separation allowed a 5-group stone classification scheme. Some overlapping between particular stone types still exists, including brushite and calcium oxalate. PMID:21606290

Cystoman® and calculi: a good alternative to standard therapies in preventing stone recurrence.

PubMed

Proietti, S; Giannantoni, A; Luciani, L G; Sortino, G; Graziotti, P; Giusti, G

2014-08-01

To assess the efficacy and tolerability of D-mannose-containing product (Cystoman(®)) in preventing recurrence in patients who underwent surgical treatment for infection related urinary stones. From January 2011 to February 2013 we have enrolled all consecutive patients affected by staghorn calculi and recurrent urinary tract infections (UTIs). All patients recommended for surgery were scheduled for percutaneous nephrolithotomy. The study agent was administered daily for 5 months after surgical procedure. At baseline and 5-month follow-up all patients underwent abdominal Computed Tomography (CT) scan and they also completed Medical Outcomes Study short-form, 36-item questionnaire (SF-36). They performed urine and urine culture monthly. The primary endpoints were the assessment of the efficacy with regard to infection-related urinary stone recurrence and the tolerability of Cystoman(®). The secondary endpoint was the evaluation of quality-of-life symptoms. During the study period, a total of 27 patients were included in the study. The data from 25 patients were analyzable. Seventeen patients (68%) did not report UTIs during follow-up. Eight patients (32%) remained infected and the average number of UTIs was 2.6 ± 1.6 in 5 months. At 5-month follow-up 17 (68%) patients were free from stones recurrence; in 8 (32%) cases CT scan revealed stone recurrence with an average stone diameter of 1.1 ± 0.4 cm. In nonrecurring patients, 2 (11.7%) reported an average of 1.5 ± 0.7 UTIs episodes; in recurring patients, 6 (75%) showed 3 ± 1.67 of UTIs episodes. Statistically significant differences were seen in the occurrence of UTIs episodes were detected between nonrecurring stone patients and recurring patients (p < 0.05). Moreover, statistically significant changes were detected in SF-36 scores from baseline to month 5 in the categories of physical functioning and energy/fatigue (p < 0.05). Cystoman(®) is effective in preventing infection-related urinary stones.

Comparison of small diameter stone baskets in an in vitro caliceal and ureteral model.

PubMed

Korman, Emily; Hendlin, Kari; Chotikawanich, Ekkarin; Monga, Manoj

2011-01-01

Three small diameter (<1.5F) stone baskets have recently been introduced. Our objective was to evaluate the stone capture rate of these baskets in an in vitro ureteral model and an in vitro caliceal model using novice, resident, and expert operators. Sacred Heart Medical Halo™ (1.5F), Cook N-Circle(®) Nitinol Tipless Stone Extractor (1.5F), and Boston Scientific OptiFlex(®) (1.3F) stone baskets were tested in an in vitro ureteral and a caliceal model by three novices, three residents, and three experts. The caliceal model consisted of a 7-cm length of 10-mm O.D. plastic tubing with a convex base. Each operator was timed during removal of a 3-mm calculus from each model with three repetitions for each basket. Data were analyzed by analysis of variance single factor tests and t tests assuming unequal variances. In the ureteral model, the Halo had the fastest average rate of stone extraction for experts and novices (0:02 ± 0:01 and 0:08 ± 0:04 min, respectively), as well as the overall fastest average stone extraction rate (0:08 ± 0:06 min). No statistical significant differences in extraction times between baskets were identified in the resident group. In the novice group, the Halo stone extraction rate was significantly faster than the OptiFlex (P=0.029). In the expert group, the OptiFlex had statistically significant slower average extraction rates compared with the Halo (P=0.005) and the N-Circle (P=0.017). In the caliceal model, no statistically significant differences were noted. While no significant differences were noted in extraction times for the caliceal model, the extraction times for the ureteral model were slowest with the OptiFlex basket. Other variables important in selection of the appropriate basket include operator preference, clinical setting, and cost.

Pneumatic ureteroscopic lithotripsy: is it still a reasonable treatment option for multiple ureteric stones?

PubMed

Isen, Kenan

2012-01-01

To assess the efficacy and safety of ureteroscopic pneumatic lithotripsy for multiple ureteric stones. 36 patients with multiple ureteric stones were treated with ureteroscopic lithotripsy (URSL). A 8/9.8-Fr Wolf semirigid ureteroscope and pneumatic lithotripter were used for stone fragmentation. 87 stones were treated with URSL. Successful fragmentation was achieved in 77 (88.5%) of the stones. The retreatment rate was 11.5%. The stone-free rate (SFR) of lower ureteric stones (93.3%) and middle ureteric stones (87.5%) was significantly higher compared with upper (73.3%) ureteric stones (p < 0.05). For patients with stones less than 1 cm and greater than 1 cm, the SFR was 91.5 and 75.0%, respectively (p < 0.05). Perforation occurred in 1 patient, mucosal injury occurred in 5 and stone migration in 5. No long-term complication was observed in any patient. Ureteroscopic pneumatic lithotripsy is still a reasonable treatment option for multiple ureteric stones. The procedure has high success rates with minimal morbidity. However, success rate can be affected by stone size and ureteric location. Copyright © 2012 S. Karger AG, Basel.

Predictive value of low tube voltage and dual-energy CT for successful shock wave lithotripsy: an in vitro study.

PubMed

Largo, Remo; Stolzmann, Paul; Fankhauser, Christian D; Poyet, Cédric; Wolfsgruber, Pirmin; Sulser, Tullio; Alkadhi, Hatem; Winklhofer, Sebastian

2016-06-01

This study investigates the capabilities of low tube voltage computed tomography (CT) and dual-energy CT (DECT) for predicting successful shock wave lithotripsy (SWL) of urinary stones in vitro. A total of 33 urinary calculi (six different chemical compositions; mean size 6 ± 3 mm) were scanned using a dual-source CT machine with single- (120 kVp) and dual-energy settings (80/150, 100/150 Sn kVp) resulting in six different datasets. The attenuation (Hounsfield Units) of calculi was measured on single-energy CT images and the dual-energy indices (DEIs) were calculated from DECT acquisitions. Calculi underwent SWL and the number of shock waves for successful disintegration was recorded. The prediction of required shock waves regarding stone attenuation/DEI was calculated using regression analysis (adjusted for stone size and composition) and the correlation between CT attenuation/DEI and the number of shock waves was assessed for all datasets. The median number of shock waves for successful stone disintegration was 72 (interquartile range 30-361). CT attenuation/DEI of stones was a significant, independent predictor (P < 0.01) for the number of required shock waves with the best prediction at 80 kVp (β estimate 0.576) (P < 0.05). Correlation coefficients between attenuation/DEI and the number of required shock waves ranged between ρ = 0.31 and 0.68 showing the best correlation at 80 kVp (P < 0.001). The attenuation of urinary stones at low tube voltage CT is the best predictor for successful stone disintegration, being independent of stone composition and size. DECT shows no added value for predicting the success of SWL.

Is endoscopic papillary large balloon dilation safe for treating large CBD stones?

PubMed

Shim, Chan Sup; Kim, Ji Wan; Lee, Tae Yoon; Cheon, Young Koog

2016-01-01

In recent years, endoscopic papillary large balloon dilation (EPLBD) with endoscopic sphincterotomy (EST) has been shown to be an effective technique for the removal of large or difficult common bile duct (CBD) stones, as an alternative to EST. Reviewing the literature published since 2003, it is understood that EPLBD has fewer associated overall complications than EST. Bleeding occurred less frequently with EPLBD than with EST. There was no significant difference in postendoscopic retrograde cholangiopancreatography pancreatitis or perforation. Recent accumulated results of EPLBD with or even without EST suggest that it is a safe and effective procedure for the removal of large or difficult bile duct stones without any additional risk of severe adverse events, when performed under appropriate guidelines. Since use of a larger balloon can tear the sphincter as well as the bile duct, possibly resulting in bleeding and perforation, a balloon size that is equal to or smaller in diameter than the diameter of the native distal bile duct is recommended. The maximum transverse diameter of the stone and the balloon-stone diameter ratio have a tendency to affect the success or failure of complete removal of stones by large balloon dilation to prevent adverse effects such as perforation and bleeding. One should take into account the size of the native bile duct, the size and burden of stones, the presence of stricture of distal bile duct, and the presence of the papilla in or adjacent to a diverticulum. Even though the results of EPLBD indicate that it is a relatively safe procedure in patients with common duct stones with a dilated CBD, the recommended guidelines should be followed strictly for the prevention of major adverse events such as bleeding and perforation.

COMPUTED TOMOGRAPHY VERSUS PLAIN RADIOGRAM IN EVALUATION OF RESIDUAL STONES AFTER PERCUTANEOUS NEPHROLITHOTOMY OR PYELONEPHROLITHOTOMY FOR COMPLEX MULTIPLE AND BRANCHED KIDNEY STONES.

PubMed

Wishahi, Mohamed; Elganzoury, Hossam; Elkhouly, Amr; Kamal, Ahmed M; Badawi, Mohamed; Eseaily, Khalid; Kotb, Samir; Morsy, Mohamed

2015-08-01

This study compared the efficacy of computed tomography of the urinary tract (CT urography) versus plain X-ray of the urinary tract (KUB) in detection and evaluation of the significance of residual stone after percutaneous nephrolithotripsy (PCNL) or surgical pyelonephrolithotomy (SPNL) for complex branching or multiple stones in the kidney. A retrospective prospective archival cohort of 168 patients underwent PCNL or SPNL for large stag horn or multiple stones in the kidney were evaluated, they were 113 patients who underwent SPNL, and 55 patients underwent PCNL. In all patients they had KUB second day of the operation, those who had multiple kidney punctures in the PCNL procedure for multiple stones, or multiple nephrotomies in the SPNL procedure, or had a radiolucent stones had an additional imaging with CT urography. Indications for the CT urography were cases of radiolucent stones and multiple small calyceal stones detected pre-operatively. The study was conducted between March 2010 and December 2014, data weie retrospectively analyzed. Preoperatively multiple or branching stones were diagnosed with intravenous urography and CT urography. Stone size and location were mapped pre-operatively on a real-size drawing, and three dimensional computed construction images in multiple planes. All patients were informed about the advantages, disadvantages and probable complications of both PCNL and SPNL before the selection of the procedure. Patients decided the type of the surgery type by themselves and written informed consent was obtained from all patients prior to the surgery. Patients were in two groups according to the patient's preference of surgery type. Group 1 consisted of 113 patients who underwent SPNL and Group 2 consisted of 55 patients treated with PCNL. Detection of residual stones stone postoperatively using KUB and CT urography was evaluated in both groups. There was statistical significance between the two imaging methodology in detection of residual stones after PCNL and/or SPNL. CT urography detected stones of 2 mm and up to 5mm which was not visualized with KUB. CT urography was statistically significant and precise in detecting the radiolucent stones of uric acid, urate, and phostate stones which were not detected by KUB.

Comparison of STONE, CROES and Guy's nephrolithometry scoring systems for predicting stone-free status and complication rates after percutaneous nephrolithotomy in obese patients.

PubMed

Ozgor, Faruk; Yanaral, Fatih; Savun, Metin; Ozdemir, Harun; Sarilar, Omer; Binbay, Murat

2017-07-29

In this study, we aim to evaluate the accuracy of STONE (stone size, tract length, obstruction, number of involved calyces, and essence/stone density), Clinical Research Office of the Endourological Society (CROES), and Guy's nephrolithometry scoring systems (NSS) in obese patients. The charts of patients who underwent percutaneous nephrolithotomy (PNL) between June 2008 and June 2016 were retrospectively analyzed. Calculations of the STONE, CROES, and Guy's NSS were performed by a resident who was well informed regarding each NSS. Patients were classified under nine scores according to STONE, four grades according to CROES, and four grades according to Guy's NSS. In total, 248 obese patients were enrolled in the study. Stone size was significantly higher in patients without stone-free status (p = 0.001). In patients who were stone-free and those with residual stones, the mean STONE score was 9.71 and 9.23 (p = 0.160), CROES was 172 and 129 (p = 0.001), and Guy's NSS was 1.67 and 2.75 (p = 0.001). Multivariate regression analysis identified the CROES and Guy's NSS were independent factors for PNL success in obese patients (p = 0.01 and p = 0.01, respectively). The CROES and Guy's NSS showed good accuracy with PNL success (AUC = 0.777 and AUC = 0.844, respectively). None of the three NSS systems were statically associated with a complication rate (p = 0.23 for STONE, p = 0.14 for CROES, and p = 0.51 for Guy's NSS). Our study demonstrated that CROES and Guy's NSS were independent predictors of stone-free rate following PNL in obese patients. Our study also revealed that three of the NSSs were not useful for predicting PNL complications in obese patients.

Ultrasonography-guided PNL in comparison with laparoscopic ureterolithotomy in the management of large proximal ureteral stone.

PubMed

Karami, Hossein; Mazloomfard, Mohammad Mohsen; Lotfi, Behzad; Alizadeh, Asghar; Javanmard, Babak

2013-01-01

The aim of study was to evaluate the clinical outcomes of PNL in comparison with laparoscopic ureterolithotomy (LUL) in proximal ureteral stones larger than 1 cm. A total of 80 patients who were candidates for treatment of large ureteral stones in our urology center were enrolled in the study between September 2004 and September 2008. By using patient randomization, they were assigned into two forty-patient groups (PNL and LUL). After evaluating the patients with laboratory tests and IVP, PNL was performed under sonography guidance in the prone position or the patients were submitted to classic laparoscopic ureterolithotomy (LUL) transperitoneally. All patients underwent postoperative assessments including KUB and ultrasonography. A hundred-percent success was achieved in both groups. The mean age of the patients were 39.4 (16-63) and 35.2 (18-57) years old in PNL and LUL groups, respectively. The mean stone size in PNL group was 14.2 (10-25) mm and in LUL group was 13.5 (10-28) mm. The duration of the operations were 54.35 (50-82) minutes, and 82.15 (73-180) minutes (P < 0.0001); and the average hospital stay days were 2.6 (2-5) and 3.5 (3-8) days (p = 0.011) in groups PNL and LUL, accordingly. The mean Hb decrease in PNL group was 0.9mg/dL and in LUL group was 0.4mg/dL (p = 0.001). No statistically significant differences in terms of blood transfusion, fever, ICU admission, and prolonged urinary leakage were detected in both groups. According to our study, percutaneous nephrolithotomy under ultrasonography guidance is comparable with the laparoscopic ureterolithotomy for the treatment of proximal ureteral stones larger than 1 cm.

Bilateral Same-Session Ureteroscopy for Treatment of Ureteral Calculi: A Systematic Review and Meta-Analysis.

PubMed

Ge, Hongwei; Zheng, Xiaoqing; Na, Yanqun; Hou, Xinzhi; Yu, Chengfan; Ding, Wenting; Wang, Yuyong; Yu, Zhijian; He, Huadong

2016-11-01

The traditional procedure for the management of bilateral ureteral stones is staged ureteroscopic lithotripsy (URS). However, in recent years particularly, some urologists advocate same-session bilateral URS on the ground of success rates and minimal morbidity. This systematic review is to evaluate the efficacy and safety of same-session bilateral ureteroscopy for the treatment of ureteral calculi. We conducted a bibliographic search using MEDLINE (1980 to August 2015) and EMBASE (1980 to August 2015). Review articles and abstract data were excluded and only studies in English reporting on outcomes of bilateral URS were included in this meta-analysis. Two reviewers independently assessed the quality of each included studies and extracted data. STATA 12.0 was used for meta-analysis. In 11 studies, 431 patients were reportedly treated with bilateral URS. Most of the stone sizes were not larger than 20 mm. The mean stone-free rate is 96% for the distal ureter, 85% for the middle ureter, and 72% for the proximal ureter. The mean operative time ranged from 45 to 100 minutes with an average hospital stay from 2 to 4 days. The overall complications rates were 17%, with the incidence of postoperative fever 4%, postoperative pain 20%, and gross hematuria 4%. Other complications, including urosepsis, urinary tract infection, small mucosal laceration, stone migration, and ureteral perforation, accounted for 6% of overall complications. This meta-analysis found that bilateral same-session ureteroscopy could achieve a high overall stone-free rate. There might be a relatively higher complication incidence, but most of the complications are minor. For selected cases, bilateral URS could be safe and effective.

Absolute Hounsfield unit measurement on noncontrast computed tomography cannot accurately predict struvite stone composition.

PubMed

Marchini, Giovanni Scala; Gebreselassie, Surafel; Liu, Xiaobo; Pynadath, Cindy; Snyder, Grace; Monga, Manoj

2013-02-01

The purpose of our study was to determine, in vivo, whether single-energy noncontrast computed tomography (NCCT) can accurately predict the presence/percentage of struvite stone composition. We retrospectively searched for all patients with struvite components on stone composition analysis between January 2008 and March 2012. Inclusion criteria were NCCT prior to stone analysis and stone size ≥4 mm. A single urologist, blinded to stone composition, reviewed all NCCT to acquire stone location, dimensions, and Hounsfield unit (HU). HU density (HUD) was calculated by dividing mean HU by the stone's largest transverse diameter. Stone analysis was performed via Fourier transform infrared spectrometry. Independent sample Student's t-test and analysis of variance (ANOVA) were used to compare HU/HUD among groups. Spearman's correlation test was used to determine the correlation between HU and stone size and also HU/HUD to % of each component within the stone. Significance was considered if p<0.05. Fourty-four patients met the inclusion criteria. Struvite was the most prevalent component with mean percentage of 50.1%±17.7%. Mean HU and HUD were 820.2±357.9 and 67.5±54.9, respectively. Struvite component analysis revealed a nonsignificant positive correlation with HU (R=0.017; p=0.912) and negative with HUD (R=-0.20; p=0.898). Overall, 3 (6.8%) had <20% of struvite component; 11 (25%), 25 (56.8%), and 5 (11.4%) had 21% to 40%, 41% to 60%, and 61% to 80% of struvite, respectively. ANOVA revealed no difference among groups regarding HU (p=0.68) and HUD (p=0.37), with important overlaps. When comparing pure struvite stones (n=5) with other miscellaneous stones (n=39), no difference was found for HU (p=0.09) but HUD was significantly lower for pure stones (27.9±23.6 v 72.5±55.9, respectively; p=0.006). Again, significant overlaps were seen. Pure struvite stones have significantly lower HUD than mixed struvite stones, but overlap exists. A low HUD may increase the suspicion for a pure struvite calculus.

Which Should be Preferred for Moderate-Size Kidney Stones? Ultramini Percutaneous Nephrolithotomy or Retrograde Intrarenal Surgery?

PubMed

Demirbas, Arif; Resorlu, Berkan; Sunay, Mehmet Melih; Karakan, Tolga; Karagöz, Mehmet Ali; Doluoglu, Omer Gokhan

2016-12-01

Comparison of effectiveness and safety of ultramini percutaneous nephrolithotomy (UMPNL) and retrograde intrarenal surgery (RIRS) in treatment of moderate-sized renal stones. The patients scheduled for surgery attributable to renal stones with the greatest diameter of 10 to 25 mm were prospectively analyzed. Patients were randomized into groups with tossing a coin method. The patients who had UMPNL and RIRS were defined as Group I and Group II, respectively. The groups were compared for demograhic data, stone characteristics, operative and postoperative data, stone-free status, and the complications. Student's t-test and Pearson's Chi square tests were used for statistical analysis. p < 0.05 was considered as statistically significant. There were 30 patients in Group I, and 43 patients in Group II. The groups were similar for age, gender, side of the stone, and surface area characteristics of the stone (p = 0.194, p = 0.470, p = 0.990, and p = 0.487, respectively). Stone-free rate was 80% (n = 24) in UMPNL, and 74.4% (n = 32) in RIRS (p = 0.579). Modified Clavien Classification Grade 1 to 2 and 3A to 3B complications were similar in two groups (p = 0.959 and p = 0.192, respectively). Comparison of stone-free rates was 93.3% in UMPNL, and 42.9% in RIRS groups for lower pole stones (p = 0.009). Groups I and II were significantly different for visual analog scale scores for postoperative pain (4.73 ± 1.25 vs 2.30 ± 1.12), hospital stay (2.46 ± 3.02 vs 1.37 ± 1.48 days), and time to return to normal daily life (11.26 ± 5.55 vs 6.65 ± 4.30 days) (p < 0.001, p < 0.001, and p < 0.001, respectively). Both UMPNL and RIRS procedures are effective and safe methods in treatment of middle-sized renal stones. However, UMPNL is more effective than RIRS in treatment of lower pole stones. RIRS is more advantageous when loss from work is taken into consideration.

[Clinical analysis of percutaneous nephrolithotomy for staghorn calculi with different stone branch number].

PubMed

Qi, Shi-yong; Zhang, Zhi-hong; Zhang, Chang-wen; Liu, Ran-lu; Shi, Qi-duo; Xu, Yong

2013-12-01

To investigate the impact of staghorn stone branch number on outcomes of percutaneous nephrolithotomy (PNL). From January 2009 to January 2013, the 371 patients with staghorn stones who were referred to our hospital for PNL were considered for this study. All calculi were showed with CT 3-dimentional reconstruction (3-DR) imaging. The computerized database of the patients had been reviewed. Our exclusion criterion was patients with congenital renal anomalies, such as horse-shoe and ectopic kidneys. And borderline stones that branched to one major calyx only were also not included. From 3-DR images, the number of stone branching into minor renal calices was recorded. We made "3" as the branch breakdown between groups. And the patients were divided into four groups. The number of percutaneous tract, operative time, staged PNL, intra-operative blood loss, complications, stone clearance rate, and postoperative hospital day were compared. The 371 patients (386 renal units) underwent PNL successfully, included 144 single-tract PNL, 242 multi-tract PNL, 97 staged PNL. The average operative time was (100 ± 50) minutes; the average intra-operative blood loss was (83 ± 67) ml. The stone clearance rate were 61.7% (3 days) and 79.5% (3 months). The postoperative hospital stay was (6.9 ± 3.4) days. A significantly higher ratio of multi-tract (χ(2) = 212.220, P < 0.01) and staged PNL (χ(2) = 49.679, P < 0.01), longer operative time (F = 4.652, P < 0.01) and postoperative hospital day (F = 2.067, P = 0.043) and lower rate of stone clearance (χ(2) = 10.691 and 47.369, P < 0.05) were found in PNL for calculi with stone branch number ≥ 5. There was no statistically meaningful difference among the 4 groups based on Clavien complication system (P = 0.460). The possibility of multi-tract and staged PNL, lower rate of stone clearance and longer postoperative hospital day increase for staghorn calculi with stone branch number more than 5.

Evaluation with Decision Trees of Efficacy and Safety of Semirigid Ureteroscopy in the Treatment of Proximal Ureteral Calculi.

PubMed

Sancak, Eyup Burak; Kılınç, Muhammet Fatih; Yücebaş, Sait Can

2017-01-01

The decision on the choice of proximal ureteral stone therapy depends on many factors, and sometimes urologists have difficulty in choosing the treatment option. This study is aimed at evaluating the factors affecting the success of semirigid ureterorenoscopy (URS) using the "decision tree" method. From January 2005 to November 2015, the data of consecutive patients treated for proximal ureteral stone were retrospectively analyzed. A total of 920 patients with proximal ureteral stone treated with semirigid URS were included in the study. All statistically significant attributes were tested using the decision tree method. The model created using decision tree had a sensitivity of 0.993 and an accuracy of 0.857. While URS treatment was successful in 752 patients (81.7%), it was unsuccessful in 168 patients (18.3%). According to the decision tree method, the most important factor affecting the success of URS is whether the stone is impacted to the ureteral wall. The second most important factor affecting treatment was intramural stricture requiring dilatation if the stone is impacted, and the size of the stone if not impacted. Our study suggests that the impacted stone, intramural stricture requiring dilatation and stone size may have a significant effect on the success rate of semirigid URS for proximal ureteral stone. Further studies with population-based and longitudinal design should be conducted to confirm this finding. © 2017 S. Karger AG, Basel.

Efficacy and safety of Ho:YAG Laser Lithotripsy for ureteroscopic removal of proximal and distal ureteral calculi

PubMed Central

2014-01-01

Background Laser lithotripsy is an established endourological modality. Ho:YAG laser have broadened the indications for ureteroscopic stone managements to include larger stone sizes throughout the whole upper urinary tract. Aim of current work is to assess efficacy and safety of Ho:YAG laser lithotripsy during retrograde ureteroscopic management of ureteral calculi in different locations. Methods 88 patients were treated with ureteroscopic Ho:YAG laser lithotripsy in our institute. Study endpoint was the number of treatments until the patient was stone-free. Patients were classified according to the location of their stones as Group I (distal ureteric stones, 51 patients) and group II (proximal ureteral stones, 37). Group I patients have larger stones as Group II (10.70 mm vs. 8.24 mm, respectively, P = 0.020). Results Overall stone free rate for both groups was 95.8%. The mean number of procedures for proximal calculi was 1.1 ± 0.1 (1–3) and for distal calculi was 1.0 ± 0.0. The initial treatment was more successful in patients with distal ureteral calculi (100% vs. 82.40%, respectively, P = 0.008). No significant difference in the stone free rate was noticed after the second laser procedure for stones smaller versus larger than 10 mm (100% versus 94.1%, P = 0.13). Overall complication rate was 7.9% (Clavien II und IIIb). Overall and grade-adjusted complication rates were not dependant on the stone location. No laser induced complications were noticed. Conclusions The use of the Ho:YAG laser appears to be an adequate tool to disintegrate ureteral calculi independent of primary location. Combination of the semirigid and flexible ureteroscopes as well as the appropriate endourologic tools could likely improve the stone clearance rates for proximal calculi regardless of stone-size. PMID:25107528

Effect of Cystone® on urinary composition and stone formation over a one year period.

PubMed

Erickson, S B; Vrtiska, T J; Lieske, J C

2011-07-15

Kidney stones are a common problem for which inadequate prevention exists. We recruited ten recurrent kidney stone formers with documented calcium oxalate stones into a two phased study to assess safety and effectiveness of Cystone(®), an herbal treatment for prevention of kidney stones. The first phase was a randomized double-blinded 12 week cross over study assessing the effect of Cystone(®) vs. placebo on urinary supersaturation. The second phase was an open label one year study of Cystone(®) to determine if renal stone burden decreased, as assessed by quantitative and subjective assessment of CT. Results revealed no statistically significant effect of Cystone(®) on urinary composition short (6 weeks) or long (52 weeks) term. Average renal stone burden increased rather than decreased on Cystone(®). Therefore, this study does not support the efficacy of Cystone(®) to treat calcium oxalate stone formers. Future studies will be needed to assess effects on stone passage, or on other stone types. Copyright © 2011 Elsevier GmbH. All rights reserved.

[The use of local vibration and ultrasound in the rehabilitation of urolithiasis patients with the "stone pathway" syndrome of the distal ureter].

PubMed

Li, A A; Nesterov, N I; Avilov, V Ia

1996-01-01

Sequential intrarectal impacts with local vibration and ultrasound on distal part of ureter in 60 patients with "stone pathway" promoted elimination of the stone fragments in 58 (96.7%) patients. The size of the urolith fragments varied from 1 to 5 mm.

Novel ultrasound method to reposition kidney stones

PubMed Central

Shah, Anup; Owen, Neil R.; Lu, Wei; Cunitz, Bryan W.; Kaczkowski, Peter J.; Harper, Jonathan D.; Bailey, Michael R.; Crum, Lawrence A.

2011-01-01

The success of surgical management of lower pole stones is principally dependent on stone fragmentation and residual stone clearance. Choice of surgical method depends on stone size, yet all methods are subject to post-surgical complications resulting from residual stone fragments. Here we present a novel method and device to reposition kidney stones using ultrasound radiation force delivered by focused ultrasound and guided by ultrasound imaging. The device couples a commercial imaging array with a focused annular array transducer. Feasibility of repositioning stones was investigated by implanting artificial and human stones into a kidney-mimicking phantom that simulated a lower pole and collecting system. During experiment, stones were located by ultrasound imaging and repositioned by delivering short bursts of focused ultrasound. Stone motion was concurrently monitored by fluoroscopy, ultrasound imaging, and video photography, from which displacement and velocity were estimated. Stones were seen to move immediately after delivering focused ultrasound and successfully repositioned from the lower pole to the collecting system. Estimated velocities were on the order of 1 cm/s. This in vitro study demonstrates a promising modality to facilitate spontaneous clearance of kidney stones and increased clearance of residual stone fragments after surgical management. PMID:20967437

[Two cases of giant female urethral stone in long-term bedridden elderly].

PubMed

Kato, K; Murase, T; Kuromatsu, I; Hasegawa, M; Kawamura, J

2001-08-01

A 78-year-old female suffering from a cerebral infarction and subdural hematoma was referred to us due to a hard mass in the anterior vaginal wall which was disclosed during gynecological examination. An abdominal X-ray, computed tomography (CT) and magnetic resonance imaging (MRI) showed that a large spindle-shaped stone, 60 x 42 mm in size, was impacting the urethra. It was impossible to catheterize the urethra. The stone gradually projected through the external urethral meatus and was removed by grasping and drawing with forceps. Another 83-year-old female with senile dementia was referred to us because of macrohematuria. An abdominal X-ray and CT showed the presence of two oval bladder stones, 32 x 24 mm and 30 x 21 mm in size. During a follow-up, one of the stones projected partially through the external urethral meatus and was removed by drawing with forceps. After a week, the other stone impacted the urethra and was removed in the same way. Both women were frail, bedridden institutionalized elderly with severe dementia, and their urination had been managed with diapers for years. As the proportion of elderly people in Japan rapidly increases, female urethral stones migrating from the urinary bladder, once very rare, may increase in number, to which we must pay attention.

Extracorporeal shock wave lithotripsy of proximal and distal ureteral stones.

PubMed

Pettersson, B; Tiselius, H G

1988-01-01

Extracorporeal shock wave lithotripsy (ESWL) was used for treatment of 105 patients with ureteral stones. There were 77 stones in the upper part of the ureter, i.e. above the pelvic brim, and 28 in the lower part, i.e. below the sacroiliac joint. Successful fragmentation was attained in 101 (96%). In 93% of the patients with stones in the upper ureter and in 100% with stones in the lower ureter the fragments were eliminated completely. In 87% of the patients with stones in the upper ureter, a ureteral catheter was introduced under local anesthesia but without fluoroscopic control. It was thereby possible to remove 30% of the stones from the ureter to the kidney. For the remaining stones, saline was infused through the catheter during ESWL. For patients with stones in the lower part of the ureter, a ureteral catheter was passed in 79% and saline infused during treatment. Whereas some form of anesthesia was used for treatment of all upper ureteral stones, 89% of the treatments for lower ureteral stones were performed without anesthesia. Auxiliary procedures after ESWL were limited to four ureteral catheter manipulations for distal stones. Four proximal stones which remained unaffected by ESWL had to be treated by open surgery (3 stones) or percutaneous surgery (1 stone). Of 82 ureteric stones treated in situ the success fragmentation rate was 95%. The average number of ESWL sessions was 1.04 for both proximal and distal ureteral stones.

Treatment efficacy and outcomes using a third generation shockwave lithotripter.

PubMed

Neisius, Andreas; Wöllner, Jens; Thomas, Christian; Roos, Frederik C; Brenner, Walburgis; Hampel, Christian; Preminger, Glenn M; Thüroff, Joachim W; Gillitzer, Rolf

2013-11-01

To evaluate the clinical efficiency of a third generation electromagnetic shock wave lithotripter, the Lithoskop(®) (Siemens, Erlangen, Germany), regarding outcomes, stone disintegration, retreatment and complication rates. To compare the results of the Lithoskop with other currently available systems and the reference standard lithotripter, the HM-3 (Dornier MedTech Europe GmbH, Wessling, Germany). We analysed the data from 183 patients, including 13 children, undergoing extracorporeal shock wave lithotripsy (ESWL) for renal and ureteric calculi collected from a prospectively populated database. Outcomes were assessed by plain abdominal film of kidney, ureter and bladder and renal ultrasonography for radiopaque and computerized tomography for radiolucent stones 1 day after treatment and after 3 months. We analysed stone size and location before and after treatment, stone disintegration rate, retreatment rate, stone-free and residual fragment rates after 3 months, along with auxiliary procedures and complications. The mean (range) patient age was 48.6 (1.3-81.4) years, including 13 children with a mean (range) age of 8.4 (1.3-16.7) years, and 77% of the patients were male. In all, 46% of the calculi were localized in the kidney and 54% in the ureter. Renal stones were localized in the upper, middle and lower calyx and in the renal pelvis in 9, 29, 30 and 32% of patients, respectively. Ureteric stones were localized in the upper, mid- and distal ureter in 29, 19 and 52% of patients, respectively. The median (range) stone size before ESWL was 10 (4-25) mm in the kidney and 8 (4-28) mm in the ureteric calculi. The overall stone-free rate after 3 months was 91% (88% for renal and 93% for ureteric calculi); the mean number of sessions to achieve these rates was 1.3. Stone-free rates and the required number of sessions were determined only by stone size. In 7.1% of the patients (n = 13) post-interventional auxiliary procedures were necessary. We observed one perirenal haematoma as a major complication (0.5%), but this did not require any further therapy. Clinical stone-free rates with the Lithoskop are high and similar to those of other available systems, including the reference standard HM-3 lithotripter. Retreatment and complication rates are low, supporting the use of ESWL as first-line therapy for urinary calculi <10 mm, independent of stone location. © 2013 The Authors. BJU International © 2013 BJU International.

Single energy micro CT SkyScan 1173 for the characterization of urinary stone

NASA Astrophysics Data System (ADS)

Fitri, L. A.; Asyana, V.; Ridwan, T.; Anwary, F.; Soekersi, H.; Latief, F. D. E.; Haryanto, F.

2016-08-01

A urinary stone is a solid piece of material produced from crystallization of excreted substances in the urine. Knowledge of the composition of urinary stones is essential to determine the suitable treatment for the patient. The aim of this research was to characterize urinary stones using single energy micro CT SkyScan 1173. Six human urinary stones were scanned in vitro using 80 kV in micro CT SkyScan 1173. The produced projection, images, were reconstructed using NRecon (in-house software from SkyScan). The images of urinary stones were analyzed using CT Analyser (CT An) to obtain information of the internal structure and the Hounsfield Unit (HU) value to determine the information regarding the composition of the urinary stones, respectively. The average HU values from certain region of interests in the same slice were compared with spectral curves of known materials from National Institute of Standards and Technology (NIST). From the analysis, the composition of the six scanned stones were obtained. Two stones are composed of cystine, two are composed of struvite, two other stones are composed of struvite+cystine. In conclusion, the single energy micro CT with 80 kV can be used identifying cystine and struvite urinary stone.

Early Development of Gravity-Sensing Organs in Microgravity

NASA Technical Reports Server (NTRS)

Wiederhold, Michael L.; Gao, Wenyuan; Harrison, Jeffrey L.; Parker, Kevin A.

2003-01-01

Most animals have organs that sense gravity. These organs use dense stones (called otoliths or statoconia), which rest on the sensitive hairs of specialized gravity- and motion-sensing cells. The weight of the stones bends the hairs in the direction of gravitational pull. The cells in turn send a coded representation of the gravity or motion stimulus to the central nervous system. Previous experiments, in which the eggs or larvae of a marine mollusk (Aplysia californica, the sea hare) were raised on a centrifuge, demonstrated that the size of the stones (or test mass) was reduced in a graded manner as the gravity field was increased. This suggests that some control mechanism was acting to normalize the weight of the stones. The experiments described here were designed to test the hypothesis that, during their initial development, the mass of the stones is regulated to achieve a desired weight. If this is the case, we would expect a larger-than-normal otolith would develop in animals reared in the weightlessness of space. To test this, freshwater snails and swordtail fish were studied after spaceflight. The snails mated in space, and the stones (statoconia) in their statocysts developed in microgravity. Pre-mated adult female swordtail fish were flown on the Space Shuttle, and the developing larvae were collected after landing. Juvenile fish, where the larval development had taken place on the ground, were also flown. In snails that developed in space, the total volume of statoconia forming the test mass was 50% greater than in size-matched snails reared in functionally identical equipment on the ground. In the swordtail fish, the size of otoliths was compared between ground- and flight-reared larvae of the same size. For later-stage larvae, the growth of the otolith was significantly greater in the flight-reared fish. However, juvenile fish showed no significant difference in otolith size between flight- and ground-reared fish. Thus, it appears that fish and snails reared in space do produce larger-than-normal otoliths (or their analogs), apparently in an attempt to compensate for the reduced weight of the stones in space. The fish data suggest that there is a critical period during which altered gravity can affect the size of the test mass, since the larval, but not the juvenile, fish showed the changes.

Effect of Dietary Countermeasures and Impact of Gravity on Renal Calculi Size Distributions Predicted by PBE-System and PBE-CFD Models

NASA Technical Reports Server (NTRS)

Kassemi, M.; Thompson, D.; Goodenow, D.; Gokoglu, S.; Myers, J.

2016-01-01

Renal stone disease is not only a concern on earth but can conceivably pose a serious risk to the astronauts health and safety in Space. In this work, two different deterministic models based on a Population Balance Equation (PBE) analysis of renal stone formation are developed to assess the risks of critical renal stone incidence for astronauts during space travel. In the first model, the nephron is treated as a continuous mixed suspension mixed product removal crystallizer and the PBE for the nucleating, growing and agglomerating renal calculi is coupled to speciation calculations performed by JESS. Predictions of stone size distributions in the kidney using this model indicate that the astronaut in microgravity is at noticeably greater but still subcritical risk and recommend administration of citrate and augmented hydration as effective means of minimizing and containing this risk. In the second model, the PBE analysis is coupled to a Computational Fluid Dynamics (CFD) model for flow of urine and transport of Calcium and Oxalate in the nephron to predict the impact of gravity on the stone size distributions. Results presented for realistic 3D tubule and collecting duct geometries, clearly indicate that agglomeration is the primary mode of size enhancement in both 1g and microgravity. 3D numerical simulations seem to further indicate that there will be an increased number of smaller stones developed in microgravity that will likely pass through the nephron in the absence of wall adhesion. However, upon reentry to a 1g (Earth) or 38g (Mars) partial gravitational fields, the renal calculi can lag behind the urinary flow in tubules that are adversely oriented with respect to the gravitational field and grow agglomerate to large sizes that are sedimented near the wall with increased propensity for wall adhesion, plaque formation, and risk to the astronauts.

Estimating the Rate of Occurrence of Renal Stones in Astronauts

NASA Technical Reports Server (NTRS)

Myers, J.; Goodenow, D.; Gokoglu, S.; Kassemi, M.

2016-01-01

Changes in urine chemistry, during and post flight, potentially increases the risk of renal stones in astronauts. Although much is known about the effects of space flight on urine chemistry, no inflight incidence of renal stones in US astronauts exists and the question "How much does this risk change with space flight?" remains difficult to accurately quantify. In this discussion, we tackle this question utilizing a combination of deterministic and probabilistic modeling that implements the physics behind free stone growth and agglomeration, speciation of urine chemistry and published observations of population renal stone incidences to estimate changes in the rate of renal stone presentation. The modeling process utilizes a Population Balance Equation based model developed in the companion IWS abstract by Kassemi et al. (2016) to evaluate the maximum growth and agglomeration potential from a specified set of urine chemistry values. Changes in renal stone occurrence rates are obtained from this model in a probabilistic simulation that interrogates the range of possible urine chemistries using Monte Carlo techniques. Subsequently, each randomly sampled urine chemistry undergoes speciation analysis using the well-established Joint Expert Speciation System (JESS) code to calculate critical values, such as ionic strength and relative supersaturation. The Kassemi model utilizes this information to predict the mean and maximum stone size. We close the assessment loop by using a transfer function that estimates the rate of stone formation from combining the relative supersaturation and both the mean and maximum free stone growth sizes. The transfer function is established by a simulation analysis which combines population stone formation rates and Poisson regression. Training this transfer function requires using the output of the aforementioned assessment steps with inputs from known non-stone-former and known stone-former urine chemistries. Established in a Monte Carlo system, the entire renal stone analysis model produces a probability distribution of the stone formation rate and an expected uncertainty in the estimate. The utility of this analysis will be demonstrated by showing the change in renal stone occurrence predicted by this method using urine chemistry distributions published in Whitson et al. 2009. A comparison to the model predictions to previous assessments of renal stone risk will be used to illustrate initial validation of the model.

Potential therapeutic activity of Phlogacanthus thyrsiformis Hardow (Mabb) flower extract and its biofabricated silver nanoparticles against chemically induced urolithiasis in male Wistar rats.

PubMed

Das, Poppy; Kumar, Kiran; Nambiraj, Arunai; Rajan, Reshma; Awasthi, Rajendra; Dua, Kamal; M, Himaja

2017-10-01

Urolithiasis is a painful disorder in which stones are formed in the kidney, bladder or urethra. There are no proper therapeutic treatments available for kidney stones and people suffering from larger stones have to undergo surgery which has many side effects. A natural remedy with therapeutic effects that can dissipate and remove even the larger stones would eliminate the need of a surgery and the risks associated with it. The flowers of Phlogacanthus thyrsiformis used in culinary recipes in the north eastern India are also widely used as a folklore medicine for the treatment of kidney stones and liver disorders. The aim of this study was to evaluate the prophylactic and therapeutic activity of the aqueous extract of P. thyrsiformis flowers and its biofabricated silver nanoparticles against struvite urinary stones and calcium oxalate kidney stones. A kidney stone inhibition study was carried out on struvite stones grown in gel medium and calcium oxalate stones in rat models using an aqueous extract of P. thyrsiformis flowers and its biofabricated silver nanoparticles. The aqueous extract of P. thyrsiformis flowers and their biofabricated silver nanoparticles, obtained by a green synthetic method, were used to treat struvite urinary stones in vitro and calcium oxalate kidney stones in vivo. Struvite stones were grown in tubes by gel diffusion technique and were treated with varying concentrations of the extract and its nanoparticles. The size of the struvite stones was monitored for 96h using a travelling microscope. Calcium oxalate stones were induced in male Wistar rats by feeding ethylene glycol-ammonium chloride mixture for 14days. Both, prophylactic and therapeutic activities were evaluated by analyzing the urine, serum and histopathological parameters of the rats. The qualitative screening of water extract unveiled the presence of flavonoids as a major constituent. Both, the extract and the nanoparticles effectively reduced the size of struvite stones in vitro and eliminated calcium oxalate stones in Wistar rats in vivo. The potent therapeutic activity of both extract and silver nanoparticles was observed as compared to preventive activity. Anti-urolithiatic potency can be attributed to the presence of flavonoids. Copyright © 2017 Elsevier B.V. All rights reserved.

Pathophysiology of kidney, gallbladder and urinary stones treatment with herbal and allopathic medicine: A review

PubMed Central

Alok, Shashi; Jain, Sanjay Kumar; Verma, Amita; Kumar, Mayank; Sabharwal, Monika

2013-01-01

Medicinal plants have been known for millennia and are highly esteemed all over the world as a rich source of therapeutic agents for the prevention of various ailments. Today large number of population suffers from kidney stone, gall stone and urinary calculi. Stone disease has gained increasing significance due to changes in living conditions i.e. industrialization and malnutrition. Changes in prevalence and incidence, the occurrence of stone types and stone location, and the manner of stone removal are explained. Medicinal plants are used from centuries due to its safety, efficacy, cultural acceptability and lesser side effects as compared to synthetic drugs. The present article deals with measures to be adopted for the potential of medicinal plants in stone dissolving activity. The problem of urinary stones or calculi is a very ancient one and many remedies have been employed during the ages these stones are found in all parts of the urinary tract, the kidney, the ureters and the urinary bladder and may vary considerably in size. In the present article, an attempt has been made to emphasis on herbal option for urinary stone.

Changes in urinary stone composition in the Tunisian population: a retrospective study of 1,301 cases.

PubMed

Alaya, Akram; Nouri, Abdellatif; Belgith, Mohsen; Saad, Hammadi; Jouini, Riadh; Najjar, Mohamed Fadhel

2012-05-01

Studies that evaluate the effect of age on stone composition are scarce. The aim of this study was to highlight the changes in epidemiological characteristics (stone composition and location) of urolithiasis according to patients' age. We studied 1,301 urolithiasis patients with age ranging from 6 months to 92 yr (781 males and 520 females). Stone analysis was performed using a stereomicroscope and infrared spectroscopy to determine the morphological type and molecular composition of each stone. The annual average incidence of new stone formation was 31.7 per 100,000 persons. In 71.8% of cases, calculi were located in the upper urinary tract. Compared to other age groups, children and old men were more affected by bladder stones. Calcium oxalate monohydrate was the most frequent stone component, even though its frequency decreased with age (59.5% in young adults and 43.7% in the elderly, P<0.05) in favor of an increase in uric acid stones (11.5% in young adults and 36.4% in the elderly, P<0.05). Struvite stones were rare (3.8%) and more frequent in children than in adults. The analysis of these data showed that urinary stones in Tunisian patients are tending to evolve in the same direction as the stones in patients from industrialized countries.

Lithotripsy of gallstones by means of a quality-switched giant-pulse neodymium:yttrium-aluminum-garnet laser. Basic in vitro studies using a highly flexible fiber system.

PubMed

Hochberger, J; Gruber, E; Wirtz, P; Dürr, U; Kolb, A; Zanger, U; Hahn, E G; Ell, C

1991-11-01

The quality-switched neodymium:yttrium-aluminum-garnet laser represents a new instrument for athermal fragmentation of gallstones by transformation of optical energy into mechanical energy in the form of shock waves via local plasma formation. A highly flexible 300-micron fiber transmission system was used in basic investigations to determine the influence of varying pulse repetition rates (5-30 Hz) and pulse energies (15 and 20 mJ) on shock wave intensity and stone fragmentation in vitro for 105 biliary calculi of known size and chemical composition. After performance of 1200 shock wave pressure measurements using polyvinylidenefluoride hydrophones, stone fragmentation was analyzed by determination of fragment removal rates (volume of fragments removed per fragmentation time), ablation rates (mean volume removed per laser pulse), and median fragment sizes for each laser setting. With the quality-switched neodymium:yttrium-aluminum-garnet laser system, all concrements could be reliably disintegrated into small fragments (median diameter, 0.7-1.7 mm). Compared with pure cholesterol stones, a significantly higher fragment removal rate was achieved in cholesterol stones containing 30% calcium phosphate (P = 0.039), in cholesterol stones containing 20% pigment (P = 0.015), and in pure pigment stones (P = 0.007). Fragment removal rates, local shock wave pressures, and median grain sizes were significantly higher at a pulse energy of 20 mJ than with 15 mJ. Shock wave pressures showed a distinct dependence on pulse repetition rates at 20 mJ, yet not at 15 mJ. Because there is no evident hazard of thermal damage to tissue using the quality-switched neodymium:yttrium-aluminum-garnet laser, it appears to be a promising device for nonsurgical biliary stone therapy.

Comparison of pneumatic and laser lithotripsy in the treatment of pediatric ureteral stones.

PubMed

Atar, Murat; Bodakci, Mehmet Nuri; Sancaktutar, Ahmet Ali; Penbegul, Necmettin; Soylemez, Haluk; Bozkurt, Yasar; Hatipoglu, Namik Kemal; Cakmakci, Suleyman

2013-06-01

To compare the effectiveness and safety of pneumatic and holmium:YAG laser lithotripters in the treatment of pediatric ureterolithiasis. Medical records of patients treated using pneumatic (PL) (n = 29) or laser (LL) (n = 35) lithotripter between 2009 and 2011 were retrospectively analysed. The patients were evaluated with respect to age, gender, stone size, complications, and stone-free rates 1 month after the operation. For the PL and LL groups, mean ages (8.8 ± 3.4 and 8.3 ± 3.5 years), male/female ratios (19:10 and 22:13) and stone locations were similar (p > 0.05). Mean stone sizes were 55.6 mm2 and 47.6 mm2 in the PL and LL group, respectively, with no statistically significant difference (p = 0.850). Mean operative times were 20.5 min in the PL group and 25.2 min in the LL group, with a statistically significant difference (p = 0.020). Stone-free rates 1 month after intervention were 79% in the PL group and 97% in the LL group (p = 0.022). Stone migration was detected in the PL group (n = 6) and in the LL group (n = 1). No major complication was found in either group. In the ureteroscopic treatment of pediatric ureterolithiasis, both pneumatic and laser lithotripters are effective and successful. However, laser lithotripsy has a higher stone-free rate and lower complication rate. Copyright © 2012 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

Evaluation of Kidney Stones with Reduced-Radiation Dose CT: Progress from 2011-2012 to 2015-2016-Not There Yet.

PubMed

Weisenthal, Karrin; Karthik, Priyadarshini; Shaw, Melissa; Sengupta, Debapriya; Bhargavan-Chatfield, Mythreyi; Burleson, Judy; Mustafa, Adel; Kalra, Mannudeep; Moore, Christopher

2018-02-01

Purpose To determine if the use of reduced-dose computed tomography (CT) for evaluation of kidney stones increased in 2015-2016 compared with that in 2011-2012, to determine variability in radiation exposure according to facility for this indication, and to establish a current average radiation dose for CT evaluation for kidney stones by querying a national dose registry. Materials and Methods This cross-sectional study was exempt from institutional review board approval. Data were obtained from the American College of Radiology dose registry for CT examinations submitted from July 2015 to June 2016. Study descriptors consistent with single-phase unenhanced CT for evaluation of kidney stones and associated RadLex® Playbook identifiers (RPIDs) were retrospectively identified. Facilities actively submitting data on kidney stone-specific CT examinations were included. Dose metrics including volumetric CT dose index, dose-length product, and size-specific dose estimate, when available, were reported, and a random effects model was run to account for clustering of CT examinations at facilities. A z-ratio was calculated to test for a significant difference between the proportion of reduced-radiation dose CT examinations (defined as those with a dose-length product of 200 mGy · cm or less) performed in 2015-2016 and the proportion performed in 2011-2012. Results Three hundred four study descriptors for kidney stone CT corresponding to data from 328 facilities that submitted 105 334 kidney stone CT examinations were identified. Reduced-dose CT examinations accounted for 8040 of 105 334 (7.6%) CT examinations, a 5.6% increase from the 1010 of 49 903 (2%) examinations in 2011-2012 (P < .001). Mean overall dose-length product was 689 mGy · cm (95% confidence interval: 667, 712), decreased from the mean of 746 mGy · cm observed in 2011-2012. Median facility dose-length product varied up to sevenfold, from less than 200 mGy · cm to greater than 1600 mGy · cm. Conclusion Use of reduced-radiation dose CT for evaluation of kidney stones has increased since 2011-2012, but remains low; variability of radiation dose according to facility continues to be wide. National mean CT radiation exposure for evaluation of renal colic during 2015-2016 decreased relative to 2011-2012 values, but remained well above what is reasonably achievable. © RSNA, 2017.

Wanted: suitable replacement stones for the Lede stone (Belgium)

NASA Astrophysics Data System (ADS)

De Kock, T.; Dewanckele, J.; Boone, M. A.; De Boever, W.; De Schutter, G.; Jacobs, P.; Cnudde, V.

2012-04-01

The Lede stone is an arenaceous limestone with a Lutetian age, occurring as discrete (most of the times three) stone banks in the marine sandy sediments of the Lede Formation (Belgium). It has a quartz content of approximate 40%. This increases abrasion strength and together with the cementation results in an average compressive strength of about 80-85 MPa. The cement is a microsparitic calcite cement. Other carbonate particles are both microfossils (mainly foraminifers) and macrofossils (bivalves, serpulids, echinoderms, …). This great diversity gives the stone a heterogeneous, animated appearance. The intra- and interparticle porosity is in total 5-10 % in average and the apparent density is 2400-2550 kg/m3. Another important constituent is glauconite, present in a few percent. In fresh state, the stone has a greenish-grey colour, but when it is exposed to atmospheric conditions for a couple of years, the stone acquires a yellowish to rust-coloured patina due to the weathering of glauconite. Sulphatation causes severe damage to the stone, and black gypsum crusts are common in urban environments on stones protected from runoff. This stone was excavated in both open air and underground quarries in the areas of Brussels and Ghent. The proximity of main rivers such as the Scheldt and Zenne provided transport routes for export towards the north (e.g. Antwerp and The Netherlands). Its first known use dates back to Roman times but the stone flourished in Gothic architecture due to its easy workability and its 'divine' light coloured patina. This results nowadays in a dominant occurrence in the cultural heritage of northwestern Belgium and the south of The Netherlands. Socio-economical reasons caused several declines and revivals of Lede stone in use. In the beginning of the 20th century, only a few excavation sites remained, with as main quarry the one located at Bambrugge (Belgium). By the end of the first half of the 20th century, however, no quarry sites remained. In the sixties, a sand quarry located in Balegem (Belgium) started with the extraction of Lede stone combined with its other activities. Until now, only this site supplies blocks of fresh Lede stones and it doesn't seem there will rise an opportunity of a new site in the near future. Therefore, during the huge amount of renovation works in the past century, the Lede stone was often replaced by imported (mostly French) limestones such as Massangis stone, Savonnières stone and Euville stone. The commercial value seems to have had a large impact and too little attention was paid on the optical appearance, ageing and technical compatibility of the stones. The use of especially Massangis stone was taken for granted. In the 21st century, there is a growing awareness of the impact of such consequent replacement for the historical value of our cultural heritage and several alternative stones are suggested and even used. These include stones from France, Spain and Portugal, but also from other regions in Belgium. For the moment, there is no consensus on the most appropriate replacement stone and further research should be done in order to evaluate compatibility of the different stone types with Lede stone. In this context, it is also very important to actively search for better alternatives, which resemble the Lede stone in both a mechanical and aesthetical point of view. Therefore, this abstract is an open question to its readers. Any commercial natural stone suggestions with affiliation to the aforementioned properties are welcome by e-mailing the corresponding author.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Serne, R. Jeffrey; Westsik, Joseph H.; Williams, Benjamin D.

This report describes the results from long-term laboratory leach tests performed at Pacific Northwest National Laboratory (PNNL) for Washington River Protection Solutions (WRPS) to evaluate the release of key constituents from monoliths of Cast Stone prepared with four simulated low-activity waste (LAW) liquid waste streams. Specific objectives of the Cast Stone long-term leach tests described in this report focused on four activities: 1. Extending the leaching times for selected ongoing EPA-1315 tests on monoliths made with LAW simulants beyond the conventional 63-day time period up to 609 days reported herein (with some tests continuing that will be documented later) inmore » an effort to evaluate long-term leaching properties of Cast Stone to support future performance assessment activities. 2. Starting new EPA-1315 leach tests on archived Cast Stone monoliths made with four LAW simulants using two leachants (deionized water [DIW] and simulated Hanford Integrated Disposal Facility (IDF) Site vadose zone pore water [VZP]). 3. Evaluating the impacts of varying the iodide loading (starting iodide concentrations) in one LAW simulant (7.8 M Na Hanford Tank Waste Operations Simulator (HTWOS) Average) by manufacturing new Cast Stone monoliths and repeating the EPA-1315 leach tests using DIW and the VZP leachants. 4. Evaluating the impacts of using a non-pertechnetate form of Tc that is present in some Hanford tanks. In this activity one LAW simulant (7.8 M Na HTWOS Average) was spiked with a Tc(I)-tricarbonyl gluconate species and then solidified into Cast Stone monoliths. Cured monoliths were leached using the EPA-1315 leach protocol with DIW and VZP. The leach results for the Tc-Gluconate Cast Stone monoliths were compared to Cast Stone monoliths pertechnetate.« less

Absence of bacterial imprints on struvite-containing kidney stones: a structural investigation at the mesoscopic and atomic scale.

PubMed

Bazin, Dominique; André, Gilles; Weil, Raphael; Matzen, Guy; Emmanuel, Veron; Carpentier, Xavier; Daudon, M

2012-04-01

Bacterial imprints are always observed on highly carbonated apatite kidney stones but not struvite kidney stones. Struvite and carbonated apatite stones with a high CO(3)(2-)/PO(4)(3-) rate are believed to develop from infections, but their structural differences at the mesoscopic scale lack explanation. We investigated 17 urinary calculi composed mainly of struvite or carbonated apatite by Fourier transform infrared, scanning electron microscopy, and powder neutron diffraction techniques. Carbonated apatite but not struvite stones showed bacterial imprints. If the same stone contained both carbonated apatite and struvite components, bacterial imprints were observed on the carbonated apatite but not the struvite part. Moreover, neutron powder diffraction experiments revealed the crystal size of struvite stones were larger than that of carbonated apatite stones (250 ± 50 vs 50 nm). Bacterial imprints may appear more easily on kidney stones with small nanocrystals, such as carbonated apatite than with large nanocrystals, such as struvite. This approach may help identify bacteria contributing to stone formation, perhaps with negative results of urine culture. Copyright © 2012 Elsevier Inc. All rights reserved.

The possible function of stone ramparts at the nest entrance of the blackstart.

PubMed

Leader; Yom-tov

1998-07-01

Blackstarts, Cercomela melanura, Turdidae, construct a rampart of stones at the entrance to their nests. These ramparts may reach remarkable proportions, containing hundreds of flat rocks. We investigated several hypotheses regarding the function of stone ramparts, by monitoring individually marked blackstarts at the En-Gedi Nature Reserve, Israel. Stones were collected solely by females, who carried them in their beaks, while flying to the nest, at a rate of up to one stone per min, after pair formation had occurred. The number and total weight of stones as well as rampart height showed a highly positive correlation with the size of the nest cavity opening. The rampart decreased the size of the cavity entrance to some nests by as much as 67%, which suggests an antipredator barrier function. Survival rates of eggs and chicks were extremely low and the major cause of reproductive failure was predation. Successful nests tended to be located higher off the ground than predated nests, and often contained fewer stones. Furthermore, larger females in terms of wing and tail length nested in cavities higher off the ground and built smaller ramparts containing lighter stones. An artificial nest predation experiment did not reveal a difference in predation rates between nests with and without stone ramparts. Spiny mice, Acomys sp., were the main egg predators. However, in 37% of nests with ramparts that were predated, the perpetrator flattened the rampart, suggesting that they may serve as a barricade, forcing the predator to invest time in clearing the stones in order to gain access to the nest, and perhaps allowing the nesting female sufficient time to escape. We propose, therefore, that owing to such high nest predation rates, females nesting close to the ground build stone ramparts as an 'early warning' mechanism to prevent themselves from being trapped inside nest cavities and predated. Copyright 1998 The Association for the Study of Animal Behaviour.

Percutaneous nephrolithotomy in an 8-week-old infant.

PubMed

Lee, Albert S; Bowen, Diana K; Vatsky, Seth; Zderic, Stephen A; Tasian, Gregory E

2018-06-01

We report successful percutaneous nephrolithotomy (PCNL) in an 8-week-old, 4.12 kg infant with a combined stone burden of > 2 cm in a solitary kidney. The patient was born with thoracolumbar myelomeningocele and had developed recurrent urinary tract infections. Her size precluded retrograde intrarenal surgery and shockwave lithotripsy would be unlikely to clear the stone burden. Stone analysis revealed hydroxyapatite and carbonate apatite stones, and metabolic work up revealed hypercalciuria for which chlorothiazide was started. To our knowledge, this is the youngest patient to undergo PCNL reported in the literature.

Urinary Tract Stones and Osteoporosis: Findings From the Women’s Health Initiative

PubMed Central

Carbone, Laura D; Hovey, Kathleen M; Andrews, Christopher A; Thomas, Fridtjof; Sorensen, Mathew D; Crandall, Carolyn J; Watts, Nelson B; Bethel, Monique; Johnson, Karen C

2017-01-01

Kidney and bladder stones (urinary tract stones) and osteoporosis are prevalent, serious conditions for postmenopausal women. Men with kidney stones are at increased risk of osteoporosis; however, the relationship of urinary tract stones to osteoporosis in postmenopausal women has not been established. The purpose of this study was to determine whether urinary tract stones are an independent risk factor for changes in bone mineral density (BMD) and incident fractures in women in the Women’s Health Initiative (WHI). Data were obtained from 150,689 women in the Observational Study and Clinical Trials of the WHI with information on urinary tract stones status: 9856 of these women reported urinary tract stones at baseline and/or incident urinary tract stones during follow-up. Cox regression models were used to determine the association of urinary tract stones with incident fractures and linear mixed models were used to investigate the relationship of urinary tract stones with changes in BMD that occurred during WHI. Follow-up was over an average of 8 years. Models were adjusted for demographic and clinical factors, medication use, and dietary histories. In unadjusted models there was a significant association of urinary tract stones with incident total fractures (HR 1.10; 95% CI, 1.04 to 1.17). However, in covariate adjusted analyses, urinary tract stones were not significantly related to changes in BMD at any skeletal site or to incident fractures. In conclusion, urinary tract stones in postmenopausal women are not an independent risk factor for osteoporosis. PMID:25990099

Size characteristics of stones ingested by common loons

USGS Publications Warehouse

Franson, J. Christian; Hansen, Scott P.; Pokras, Mark; Miconi, Rose

2001-01-01

Common Loon (Gavia immer) carcasses recovered in New England had more stones of greater combined mass in their stomachs than loons from the southeastern United States. Stones retained in sieves with mesh sizes between 4.75 and 8.00 mm accounted for the greatest percentage (by mass) of grit in loon stomachs. The median longest dimension of the largest single stone in each stomach was 12.5 mm in loons from New England and 10.7 mm in loons from the southeast (maximum = 23.1 mm and 16.8 mm, respectively). A recent national proposal to restrict the use of certain fishing weights in the United States called for a ban on lead fishing sinkers of 25.4 mm or less in any dimension. Our findings suggest it is unlikely that Common Loons would ingest lead fishing weights greater than 25.4 mm in any dimension, if such ingestion was solely the result of their search for replacement stones for their stomachs. However, this does not preclude the possibility that loons may ingest larger fishing weights under other circumstances, such as the consumption of fish with attached sinkers.

Comparison and Efficacy of Low-Dose and Standard-Dose Tamsulosin and Alfuzosin in Medical Expulsive Therapy for Lower Ureteral Calculi: Prospective, Randomized, Comparative Study

PubMed Central

Cha, Woo Heon; Choi, Jae Duck; Seo, Young Jin; Lee, Kyungseop

2012-01-01

Purpose Typically in Korea, for a standard dose (0.4 mg) of tamsulosin, two low doses (0.2 mg) are administered. The aim of this study was to evaluate and compare the efficacy of tamsulosin (0.2 mg and 0.4 mg) and alfuzosin (10 mg) in the treatment of lower ureteral stones. Materials and Methods A total of 141 patients presenting with a single 4- to 10-mm sized lower ureteral stone were randomly assigned to 4 groups. Patients in group 1 (n=41) and group 2 (n=30) received an oral dose of 0.2 mg tamsulosin once and twice daily, respectively, and patients in group 3 (n=36) received a daily oral dose of 10 mg alfuzosin. Patients in group 4 (n=34) received trospium chloride only. The spontaneous passage of stones, the stone expulsion time, and adverse effects were evaluated. Results There were no significant differences in patient background, including age, sex, BMI, stone size, stone side, and symptom duration. The spontaneous stone passage rate through the ureter was higher and the stone expulsion time was faster in groups 1, 2, and 3 than in group 4. There were no statistically different changes in groups 1, 2, and 3. The adverse effects observed in all groups were comparable and were mild. Conclusions Tamsulosin at 0.2 mg and 0.4 mg and alfuzosin (10 mg) proved to be safe and effective. A first cycle of medical expulsive therapy with tamsulosin 0.2 mg could be considered as an option in the management of single lower ureteral stone. PMID:22670195

Micropercutaneous cystolithotomy in children: our experience with the transillumination technique.

PubMed

Bodakci, Mehmet Nuri; Sancaktutar, Ahmet Ali; Dağgulli, Mansur; Hatipoglu, Namık Kemal; Söylemez, Haluk; Penbegul, Necmettin; Atar, Murat; Bozkurt, Yasar

2014-06-01

We present our experience with micropercutaneous cystolithotripsy (mPCCL) using transillumination-guided access in children with bladder stones and evaluate the safety and efficacy of this procedure. Twelve children who underwent mPCCL for bladder stone removal in our department between January 2011 and September 2013 were included in this study. Percutaneous access was performed using the transillumination technique. The chief complaint, age and sex of the patients, stone size, operative time, complications, stone-free rate, and stone composition as determined by radiography diffraction analysis were recorded. The mean age of the patients was 2.6 (1-7) years. One out of 12 patients was a girl. The mean stone size was 14 mm (7-32 mm). The mean mPCCL procedure time was 38.7 (15-65) minutes. The mean hospital stay was 1.4 (0.5-4) days. The stone-free rate after one mPCCL intervention was 91.6% and increased to 100% after two sessions of mPCCL. The notable complications were transient macroscopic hematuria in one patient, acute urinary retention in one patient, and the need for a second session of mPCCL in another patient. The stones were composed of calcium oxalate (3), ammonium acid urate (1), calcium phosphate (1), cystine (1), struvite (1), and unknown (5). Transillumination-guided mPCCL is a safe and effective technique, does not require the use of ionizing radiation, is technically easy, and is a minimally invasive alternative for the management of bladder stones. It has many advantages, especially in pediatric patients, such as decreased urethral injury, no need for postoperative catheter insertion in most cases, and shorter operative time.

Impact of body mass index on clinical outcomes associated with percutaneous nephrolithotomy.

PubMed

Alyami, Fahad A; Skinner, Thomas A A; Norman, Richard W

2013-01-01

Percutaneous nephrolithotomy (PCNL) is the preferred treatment for patients with large renal calculi or stones that have not responded to extracorporeal shock wave lithotripsy (ESWL). The objective of this study was to compare outcomes and complications of PCNL in patients of various body mass indices (BMI) to determine the safety of this procedure in patients with elevated BMI. A retrospective chart review of 114 patients who underwent PCNL between 2006 and 2009 was performed. Patients were separated into 4 groups with respect to their BMI: (1) ideal body weight (BMI <25 kg/m(2)), (2) overweight (BMW 25-29 kg/m(2)), (3) obese (BMI 30-39 kg/m(2)) and (4) morbidly obese (BMI ≥40 kg/m(2)). One-way ANOVA and univariate logistic regression analysis were used to assess the association between BMI (classified into 4 levels) and variables including age, sex, stone size, length of stay, incidence of complications and stone-free rates. The distribution of the 114 patients in each BMI category was: ideal body weight 39 (34%), overweight 24 (21%), obese 41 (36%), morbidly obese 10 (9%). There was no difference in the composition of groups with respect to age, sex, pharmacologically treated comorbidities or stone size. Mean length of stay in days, intra- and postoperative complication rates were not statistically different. Stone-free rates showed no significant difference between groups: 90% ideal body weight; 87% overweight; 90% obese; 80% morbidly obese (p = 0.83). Outcomes of PCNL were statistically independent of BMI. PCNL is a safe and efficacious treatment of stone disease in patients of all sizes.

Methanotrophs and methanogens in masonry

PubMed

Kussmaul; Wilimzig; Bock

1998-11-01

Methanotrophs were present in 48 of 225 stone samples which were removed from 19 historical buildings in Germany and Italy. The average cell number of methanotrophs was 20 CFU per g of stone, and their activities ranged between 11 and 42 pmol of CH4 g of stone-1 day-1. Twelve strains of methane-oxidizing bacteria were isolated. They belonged to the type II methanotrophs of the genera Methylocystis, Methylosinus, and Methylobacterium. In masonry, growth substrates like methane or methanol are available in very low concentrations. To determine if methane could be produced by the stone at rates sufficient to support growth of methanotrophs, methane production by stone samples under nonoxic conditions was examined. Methane production of 0.07 to 215 nmol of CH4 g of stone-1 day-1 was detected in 23 of 47 stone samples examined. This indicated the presence of the so-called "mini-methane"-producing bacteria and/or methanogenic archaea. Methanotrophs occurred in nearly all samples which showed methane production. This finding indicated that methanotrophs depend on biogenic methane production in or on stone surfaces of historical buildings.

Kidney Stones as an Underrecognized Clinical Sign in Pediatric Cushing Disease.

PubMed

Rahman, Sara H; Papadakis, Georgios Z; Keil, Margaret F; Faucz, Fabio R; Lodish, Maya B; Stratakis, Constantine A

2016-03-01

To investigate the prevalence of kidney stones in a population of children with Cushing disease (CD) and to compare it with the prevalence of kidney stones in healthy children. Clinical and biochemical data from 139 pediatric patients with CD (68 females, 71 males) were analyzed retrospectively. Computed tomography scans were reviewed for kidney stones. Among 139 patients, 27 with CD (19.4%) had either radiographic evidence and/or a history of kidney stones. Those with kidney stones had higher urine free cortisol (P = .008) and transsphenoidal surgery at an older age (P = .007). The average urinary calcium/creatinine ratio was elevated in patients with CD (0.22 ± 0.11). The prevalence of kidney stones was higher in children with CD than in normal children (19.42% vs 1.0%; P < .001). Our results illustrate that kidney stones are an underestimated complication of pediatric CD, especially when compared with the prevalence of nephrolithiasis in the general pediatric population. Long-term consequences for kidney function are not known and need to be studied. Published by Elsevier Inc.

Computer aided detection of ureteral stones in thin slice computed tomography volumes using Convolutional Neural Networks.

PubMed

Längkvist, Martin; Jendeberg, Johan; Thunberg, Per; Loutfi, Amy; Lidén, Mats

2018-06-01

Computed tomography (CT) is the method of choice for diagnosing ureteral stones - kidney stones that obstruct the ureter. The purpose of this study is to develop a computer aided detection (CAD) algorithm for identifying a ureteral stone in thin slice CT volumes. The challenge in CAD for urinary stones lies in the similarity in shape and intensity of stones with non-stone structures and how to efficiently deal with large high-resolution CT volumes. We address these challenges by using a Convolutional Neural Network (CNN) that works directly on the high resolution CT volumes. The method is evaluated on a large data base of 465 clinically acquired high-resolution CT volumes of the urinary tract with labeling of ureteral stones performed by a radiologist. The best model using 2.5D input data and anatomical information achieved a sensitivity of 100% and an average of 2.68 false-positives per patient on a test set of 88 scans. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Building stones and geological environment in three ancient cities of Aegean Thrace, Greece

NASA Astrophysics Data System (ADS)

Xidakis, G. S.; Diamantis, J. V.; Marinos, P. G.

1990-07-01

The type, use, and size of the structural stones employed in three ancient cities of the Aegean Thrace are considered Abdera, Maroneia, and Mesimbria. The impact of the geological environment on the choice of these materials also is examined. From the results obtained it is implied that despite the great variety of rocks exposed in the area, the rocks used in construction in these cities are mostly types of sandstone and limestone, rocks with moderate technical properties and easily obtained from the area. The quarries were within a radius of less than 10 km and the size distribution of the building stones in all towns is discussed.

Prediction of axial limit capacity of stone columns using dimensional analysis

NASA Astrophysics Data System (ADS)

Nazaruddin A., T.; Mohamed, Zainab; Mohd Azizul, L.; Hafez M., A.

2017-08-01

Stone column is the most favorable method used by engineers in designing work for stabilization of soft ground for road embankment, and foundation for liquid structure. Easy installation and cheaper cost are among the factors that make stone column more preferable than other method. Furthermore, stone column also can acts as vertical drain to increase the rate of consolidation during preloading stage before construction work started. According to previous studied there are several parameters that influence the capacity of stone column. Among of them are angle friction of among the stones, arrangement of column (two pattern arrangement most applied triangular and square), spacing center to center between columns, shear strength of soil, and physical size of column (diameter and length). Dimensional analysis method (Buckingham-Pi Theorem) has used to carry out the new formula for prediction of load capacity stone columns. Experimental data from two previous studies was used for analysis of study.

Influences of petrographic parameters on technological properties of greywackes used for crushed stone production

NASA Astrophysics Data System (ADS)

Prikryl, Richard; Cermak, Martin; Krutilova, Katerina

2014-05-01

This study focuses on the influence of petrographic parameters on technological properties of greywackes. These sedimentary rocks make about 27 % of crushed stone market in the Czech Republic. Mainly in Moravia (eastern part of the Czech Republic), greywackes represent almost exclusive high quality aggregate. The behaviour of greywackes varies, however, from quarry to quarry. In this study, we have selected the most important deposits that cover major lithological variation of local greywackes. Studied greywackes were analysed for their petrographic parameters quantitatively (using image analysis of thin sections). The pore space characteristics were determined by using fluorescent dye - epoxy resin impregnated specimens. The studied rocks are composed of subangular and angular quartz grains, lithoclasts (stable rocks: quartzites, and unstable rocks: phylites, metaphylites, siltstones, slates, greywackes, and less frequently acid eruptive rocks), feldspars (orthoclas, microcline, plagioclase), and detrital micas. Detrital and authigenic chlorite has been found as well. The matrix which represents the largest volume of rock-forming components contains a mixture of sericite, chlorite, clay minerals, cements, and clasts in aleuropelitic size. Based on the microscopic examination, all studied rock types were classified as greywacke with fine- to medium-grained massive rock fabric. Only specimen from Bělkovice has shown partly layered structure. Alteration of feldspars and unstable rock fragments represents common feature. Diagenetic features included pressure dissolution of quartz clasts and formation of siliceous and/or calcite cements. Based on the experimental study of technological performance of studied greywackes and its correlation to petrographic features, the average size of clasts and volume of matrix make the driving factors affecting the LA values. The LA values decrease with the increasing of volume of matrix (R = 0.61) and with decreasing average grain size (R = 0.44). The degree of sorting influences LA values as well; more graded greywackes tend to show higher LA values. Regarding PSV, its values increase with increasing volume of quartz clasts.

Translocation of mineralo-organic nanoparticles from blood to urine: a new mechanism for the formation of kidney stones?

PubMed

Martel, Jan; Wu, Cheng-Yeu; Young, John D

2016-09-01

Recent studies indicate that mineralo-organic nanoparticles form in various human body fluids, including blood and urine. These nanoparticles may form within renal tubules and increase in size in supersaturated urine, eventually leading to the formation of kidney stones. Here, we present observations suggesting that mineralo-organic nanoparticles found in blood may induce kidney stone formation via an alternative mechanism in which the particles translocate through endothelial and renal epithelial cells to reach urine. We propose that this alternative mechanism of kidney stone formation and the study of mineralo-organic nanoparticles in general may provide novel strategies for the early detection and treatment of ectopic calcifications and kidney stones.

[Asymptomatic Renal Stones: Do they really Exist?].

PubMed

Seseke, S; Rudolph, R; Rebmann, U

2011-11-01

Asymptomatic renal calculi without any history of colic, hematuria or infection can be found as an incidental finding during preven-tive check-ups. The aim of our study was to eval-uate whether these stones provoke symptoms with the need for further treatment during the follow-up and whether they cause cortical defects which may consecutively affect the renal func-tion. In a prospective study we evaluated 104  patients with renal calculi. The -medical history, radiological findings and functional imaging as well as urine and blood analyses were recorded and evaluated. The influence of stone size and localisation on the development of acute stone-related symptoms, renal function and renal scarring were evaluated. Furthermore, we analysed whether localised pathological findings in radiographic or functional imaging may influence the creatinine level. The follow-up was be-tween 12 and 48  months (median: 25  months). During the study period 27 / 104 of our patients (26 %) developed symptomatic events (renal colic, hematuria, infection) in which patients with middle pole calculi with a mean -cumulative stone diameter of 9.8  mm had the -highest risk. A localised renal scarring could be found in 36.6 %. These patients had a significantly higher risk in presenting an increased creatinine level. Increasing stone size was diagnosed in 39  cases (37.5 %). Asymptomatic renal stones have to be controlled regularly in order to prevent the -patient from loss of renal function and hypertension caused by increasing stones or urinary tract infection. © Georg Thieme Verlag KG Stuttgart ˙ New York.

Fragmentation and dusting of large kidney stones using compact, air-cooled, high peak power, 1940-nm, Thulium fiber laser

NASA Astrophysics Data System (ADS)

Hardy, Luke A.; Gonzalez, David A.; Irby, Pierce B.; Fried, Nathaniel M.

2018-02-01

Previous Thulium fiber laser lithotripsy (TFL) studies were limited to a peak power of 70 W (35 mJ / 500 μs), requiring operation in dusting mode with low pulse energy (35 mJ) and high pulse rate (300 Hz). In this study, a novel, compact, air-cooled, TFL capable of operating at up to 500 W peak power, 50 W average power, and 2000 Hz, was tested. The 1940-nm TFL was used with pulse duration (500 μs), average power (10 W), and fiber (270- μm-core) fixed, while pulse energy and pulse rate were changed. A total of 23 large uric acid (UA) stones and 16 large calcium oxalate monohydrate (COM) stones were each separated into 3 modes (Group 1-"Dusting"- 33mJ/300Hz; Group 2-"Fragmentation"-200mJ/50Hz; Group 3-"Dual mode"-Fragmentation then Dusting). The fiber was held manually in contact with stone on a 2-mm-mesh sieve submerged in a flowing saline bath. UA ablation rates were 2.3+/-0.8, 2.3+/-0.2, and 4.4+/-0.8 mg/s and COM ablation rates were 0.4+/-0.1, 1.0+/-0.1, and 0.9+/-0.4 mg/s, for Groups 1, 2, and 3. Dual mode provided 2x higher UA ablation rates than other modes. COM ablation threshold is 3x higher than UA, so dusting provided lower COM ablation rates than other modes. Future studies will explore higher average laser power than 10 W for rapid TFL ablation of large stones.

[Changes in kidney stones type according to sex and age in Tunisian patients].

PubMed

Alaya, A; Nouri, A; Belgith, M; Saad, H; Hell, I; Hellara, W; Jouini, R; Najjar, M F

2012-03-01

Studies that evaluate the effect of age and gender on the stone composition are scarce. The aim of this study is to highlight the modification of epidemiological characteristics of this pathology according to patients' sex and age. We studied 1269 urolithiasic patients ranging from 6 months to 92 years old and known as having urinary stones (752 males and 517 females). Stone analysis was performed respectively using a stereomicroscope and infrared spectroscopy to determine, respectively, the morphological type and molecular composition of each. The annual average incidence of new stone formation was 30.25 per 100,000 inhabitants. In 1041 patients (81%), calculi were located in the upper urinary tract. Children and old man were more affected by bladder stone. Calcium oxalate monohydrate remains the most frequent stone component even if its frequency fell according to age (63.2% in teenagers and 40.6% in elderly [p<0.05]) in favour of the increase of uric acid stones (3,5% in teenagers and 41.5% in elderly [p<0.05]). Struvite stones were rare (3.5%) and more frequent in children. The analysis of these data shows that urinary stones in Tunisia are tending to evolve in the same direction as in industrialized countries. Copyright © 2011 AEU. Published by Elsevier Espana. All rights reserved.

Prevention of stone migration with the Accordion during endoscopic ureteral lithotripsy.

PubMed

Pagnani, Christopher J; El Akkad, Magdy; Bagley, Demetrius H

2012-05-01

Endoscopic lithotripsy is often prolonged secondary to the retrograde migration of calculous fragments. Various balloons, baskets, and other devices have been used to prevent this migration. Our purpose is to analyze the effect of the Accordion(®) on stone migration and overall efficiency during lithotripsy. We prospectively evaluated 21 patients with a total of 23 distal ureteral stones. Patients underwent lithotripsy using an endoscopic impact lithotriptor. The Accordion was randomly used in 11 of these 21 patients. Data were collected regarding stone migration, stone size, stone ablation, ureteral clearing, and lengths of time for various stages of each procedure. Patients who were treated with the Accordion device experienced significantly less retrograde migration during fragmentation (P=0.0064). When stone volume was taken into account (but not on a per stone basis), ablation and ureteral clearing were also expedited, and fewer lithotripter "hits" and basket "sweeps" were needed. The Accordion device is effective in preventing the migration of stone fragments during endoscopic ureteral lithotripsy. Our data suggest that this device may also increase efficiency of the fragmentation and clearance of ureteral calculi.

Is retrograde intrarenal surgery the game changer in the management of upper tract calculi? A single-center single-surgeon experience of 131 cases.

PubMed

Parikh, Kandarp Priyakant; Jain, Ravi Jineshkumar; Kandarp, Aditya Parikh

2018-01-01

Success of any modality for stone disease needs to be evaluated in terms of Stone Free Rates (SFR), auxiliary procedures needed; complications and follow up. SFR in RIRS is subject to parameters like stone burden, location, number, hardness, composition; calyceal and ureter anatomy; use of ureteric access sheath (UAS); surgeon experience etc. The aim of this study is to evaluate the efficacy and safety of RIRS for managing upper tract stones. The objectives include evaluating SFR in RIRS in relation to stone burden, location and number. Other objectives include evaluating SFR after re RIRS in relation to stone burden, necessity of pre DJ stenting, use of UAS and post operative complication rate. 131 patients operated by single surgeon for single/multiple renal and/or upper ureteric stones were evaluated. Stone size > 3 mm on follow up CT KUB was considered as residual. Re RIRS was required for residual stones. The overall SFR was 76%. SFR were statistically lower with stone burden > 1.5 cm, lower calyceal stones and single stones with stone burden > 1.5 cm. SFR was 90% after 2 nd RIRS and 98.5% after 3 rd RIRS procedure. No significant difference in SFR was noted between single v/s multiple stones, single calyx v/s multiple calyx stones and renal v/s upper ureteric stones. No major complication was noted. Larger stone burden and lower calyceal location are important factors deciding SFR in RIRS. With auxiliary procedure, RIRS is safe and effective compared to PCNL.

Urinary stone composition in Oman: with high incidence of cystinuria.

PubMed

Al-Marhoon, Mohammed S; Bayoumi, Riad; Al-Farsi, Yahya; Al-Hinai, Abdullhakeem; Al-Maskary, Sultan; Venkiteswaran, Krishna; Al-Busaidi, Qassim; Mathew, Josephkunju; Rhman, Khalid; Sharif, Omar; Aquil, Shahid; Al-Hashmi, Intisar

2015-06-01

Urinary stones are a common problem in Oman and their composition is unknown. The aim of this study is to analyze the components of urinary stones of Omani patients and use the obtained data for future studies of etiology, treatment, and prevention. Urinary stones of 255 consecutive patients were collected at the Sultan Qaboos University Hospital. Stones were analyzed by Fourier transform infrared spectrophotometer. The biochemical, metabolic, and radiological data relating to the patients and stones were collected. The mean age was 41 years, with M:F ratio of 3.7:1. The common comorbidities associated with stone formation were hypertension; diabetes, benign prostate hyperplasia; urinary tract infection; obesity; and atrophic kidney. The common presentation was renal colic and flank pain (96%). Stones were surgically retrieved in 70% of patients. Mean stone size was 9 ± 0.5 mm (range 1.3-80). Stone formers had a BMI ≥ 25 in 56% (P = 0.006) and positive family history of stones in 3.8%. The most common stones in Oman were as follows: Calcium Oxalates 45% (114/255); Mixed calcium phosphates & calcium oxalates 22% (55/255); Uric Acid 16% (40/255); and Cystine 4% (10/255). The most common urinary stones in Oman are Calcium Oxalates. Overweight is an important risk factor associated with stone formation. The hereditary Cystine stones are three times more common in Oman than what is reported in the literature that needs further genetic studies.

Effect of imaging powder and CAD/CAM stone types on the marginal gap of zirconia crowns.

PubMed

Alghazzawi, Tariq F; Al-Samadani, Khalid H; Lemons, Jack; Liu, Perng-Ru; Essig, Milton E; Bartolucci, Alfred A; Janowski, Gregg M

2015-02-01

To compare the marginal gap using different types of die stones and titanium dies with and without powders for imaging. A melamine tooth was prepared and scanned using a laboratory 3-shape scanner to mill a polyurethane die, which was duplicated into different stones (Jade, Lean, CEREC) and titanium. Each die was sprayed with imaging powders (NP, IPS, Optispray, Vita) to form 15 groups. Ten of each combination of stone/titanium and imaging powders were used to mill crowns. A light-bodied impression material was injected into the intaglio surface of each crown and placed on the corresponding die. Each crown was removed, and the monophase material was injected to form a monophase die, which was cut into 8 sections. Digital images were captured using a stereomicroscope to measure marginal gap. Scanning electron microscopy was used to determine the particle size and shape of imaging powders and stones. Marginal gaps ranged from mean (standard deviation) 49.32 to 1.20 micrometers (3.97-42.41 μm). There was no statistical difference (P > .05) in the marginal gap by any combination of stone/titanium and imaging powders. All of the imaging powders had a similar size and rounded shape, whereas the surface of the stones showed different structures. When a laboratory 3-shape scanner is used, all imaging powders performed the same for scanning titanium abutments. However, there was no added value related to the use of imaging powder on die stone. It is recommended that the selection of stone for a master cast be based on the hysical properties. When a laboratory 3-shape scanner is used, the imaging powder is not required for scanning die stone. Whenever scanning titanium implant abutments, select the least expensive imaging powder. Copyright © 2015 American Dental Association. Published by Elsevier Inc. All rights reserved.

Urinary Tract Stones and Osteoporosis: Findings From the Women's Health Initiative.

PubMed

Carbone, Laura D; Hovey, Kathleen M; Andrews, Christopher A; Thomas, Fridtjof; Sorensen, Mathew D; Crandall, Carolyn J; Watts, Nelson B; Bethel, Monique; Johnson, Karen C

2015-11-01

Kidney and bladder stones (urinary tract stones) and osteoporosis are prevalent, serious conditions for postmenopausal women. Men with kidney stones are at increased risk of osteoporosis; however, the relationship of urinary tract stones to osteoporosis in postmenopausal women has not been established. The purpose of this study was to determine whether urinary tract stones are an independent risk factor for changes in bone mineral density (BMD) and incident fractures in women in the Women's Health Initiative (WHI). Data were obtained from 150,689 women in the Observational Study and Clinical Trials of the WHI with information on urinary tract stones status: 9856 of these women reported urinary tract stones at baseline and/or incident urinary tract stones during follow-up. Cox regression models were used to determine the association of urinary tract stones with incident fractures and linear mixed models were used to investigate the relationship of urinary tract stones with changes in BMD that occurred during WHI. Follow-up was over an average of 8 years. Models were adjusted for demographic and clinical factors, medication use, and dietary histories. In unadjusted models there was a significant association of urinary tract stones with incident total fractures (HR 1.10; 95% CI, 1.04 to 1.17). However, in covariate adjusted analyses, urinary tract stones were not significantly related to changes in BMD at any skeletal site or to incident fractures. In conclusion, urinary tract stones in postmenopausal women are not an independent risk factor for osteoporosis. © 2015 American Society for Bone and Mineral Research.

Evaluation of stone volume distribution in renal collecting system as a predictor of stone-free rate after percutaneous nephrolithotomy: a retrospective single-center study.

PubMed

Atalay, Hasan Anıl; Canat, Lutfi; Bayraktarlı, Recep; Alkan, Ilter; Can, Osman; Altunrende, Fatih

2017-06-23

We analyzed our stone-free rates of PNL with regard to stone burden and its ratio to the renal collecting system volume. Data of 164 patients who underwent PNL were analyzed retrospectively. Volume segmentation of renal collecting system and stones were done using 3D segmentation software with the images obtained from CT data. Analyzed stone volume (ASV) and renal collecting system volume (RCSV) were measured and the ASV-to-RCSV ratio was calculated after the creation of a 3D surface volume rendering of renal stones and the collecting system. Univariate and multivariate statistical analyses were performed to determine factors affecting stone-free rates; also we assessed the predictive accuracy of the ASV-to-RCSV ratio using the receiving operating curve (ROC) and AUC. The stone-free rate of PNL monotherapy was 53% (164 procedures).The ASV-to-RCSV ratio and calyx number with stones were the most influential predictors of stone-free status (OR 4.15, 95% CI 2.24-7.24, <0.001, OR 2.62, 95% CI 1.38-4.97, p < 0.001, respectively). Other factors associated with the stone-free rate were maximum stone size (p < 0.029), stone surface area (p < 0.010), and stone burden volume (p < 0.001). Predictive accuracy of the ASV-to-RCSV ratio was AUC 0.76. Stone burden volume distribution in the renal collecting system, which is calculated using the 3D volume segmentation method, is a significant determinant of the stone-free rate before PCNL surgery. It could be used as a single guide variable by the clinician before renal stone surgery to predict extra requirements for stone clearance.

Results of retrograde intrarenal surgery in the treatment of renal stones greater than 2 cm.

PubMed

Palmero, J L; Castelló, A; Miralles, J; Nuño de La Rosa, I; Garau, C; Pastor, J C

2014-05-01

To analyze the results of retrograde intrarenal surgery (RIRS) in patients with ≥2 cm stones treated in our center. A retrospective review of 106 patients with renal calculi underwent RIRS ≥2 cm (period January 2009-December 2011). The procedures were performed under general anesthesia as a source of fragmentation using the holmium laser (30 W Litho Quantasystem) and flexible ureteroscopes (X2 Flex Storz, Olympus P5) through ureteral access sheaths. It discusses demographic variables (age, medical history, antiplatelet or anticoagulant treatment, treatment of urolithiasis, BMI, ASA), treated stones variables (size, number, Hounsfield units, biochemical composition) and intra-and postoperative variables (operative time, number of pulses, hospital stay, complications) with the completion of a descriptive analysis of the same. To define our results we consider success to the complete absence of fragments or residual <5 mm posterior imaging tests. The mean stone size was 2.46 cm treated, being the only stone in 87.7% of cases. The most frequent location was the renal pelvis stones (44%) followed by the lower calyx (39%). The postoperative complication rate was 6.7%, with all of little relevance. The success rate with a single procedure was 79.4% to 94.1% with retreatment. RIRS is a valid alternative for the treatment of kidney stones ≥2 cm for its high success rate and few complications if performed in specialized centers. Copyright © 2013 AEU. Published by Elsevier Espana. All rights reserved.

Preoperative ultrasonography and prediction of technical difficulties during laparoscopic cholecystectomy.

PubMed

Daradkeh, S S; Suwan, Z; Abu-Khalaf, M

1998-01-01

A prospective study was carried out to investigate the value of preoperative ultrasound findings for predicting difficulties encountered during laparoscopic cholecystectomy (LC). Altogether 160 consecutive patients with symptomatic gallbladder (GB) disease (130 females, 30 males) referred to the Jordan University Hospital were recruited for the purpose of this study. All patients underwent detailed ultrasound examination 24 hours prior to LC. The overall difficulty score (ODS), as a dependent variable, was based on the following operative parameters: duration of surgery, bleeding, dissection of Calot's triangle, dissection of gallbladder wall, adhesions, spillage of bile, spillage of stone, and difficulty of gallbladder extraction. Multiple regression analysis was used to assess the significance of the following preoperative ultrasound variables (independent) for predicting the variation in the ODS: size of the GB, number of GB stones, size of stones, location of GB stones, thickness of GB wall, common bile duct (CBD) diameter, and liver size. Only thickness of GB wall and CBD diameter were found to be significant predictors of the variation in the ODS (adjusted R2 = 0.25). We conclude that the preoperative ultrasound examination is of value for predicting difficulties encountered during LC, but it is not the sole predictor.

Evaluating the importance of mean stone density and skin-to-stone distance in predicting successful shock wave lithotripsy of renal and ureteric calculi.

PubMed

Wiesenthal, Joshua D; Ghiculete, Daniela; D'A Honey, R John; Pace, Kenneth T

2010-08-01

Shock wave lithotripsy (SWL) is considered the first line treatment for the majority of patients with renal and ureteric calculi, with success rates from contemporary series varying from 60 to 90%. Success is dependent on many patient and stone-related factors. We conducted a retrospective analysis of mean stone CT density (MSD) and skin-to-stone distance (SSD) to determine their influence on the success of SWL of renal and ureteric calculi. Data from all patients treated at the St. Michael's Hospital Lithotripsy Unit from May 2004 to June 2009 were reviewed. Analysis was restricted to those patients with a pre-treatment non-contrast CT scan conducted at our center demonstrating a solitary renal or ureteric calculus < or =20 mm in maximal diameter. Successful treatment of renal stones was defined as those patients who were stone free or had asymptomatic, clinically insignificant residual fragments < or =4 mm in diameter, as measured by KUB X-ray, 3 months after a single SWL treatment. Successful treatment of ureteric stones was defined as being stone free on KUB X-ray, 2-weeks post-SWL. Demographic, stone, patient, treatment and follow-up data were collected from a prospective database and review of CT and KUB imaging by two independent urologists and one radiologist. Data were analyzed with logistic regression, Chi square analysis and ANOVA where appropriate. 422 patients (69.7% male) with a mean age of 51.4 years (SD 12.9) and mean BMI 27.0 kg/m(2) (SD 4.9) were analyzed. Mean stone size was 78.9 mm(2) (SD 77.3) for ureteral stones and 66.1 mm(2) (SD 63.2) for renal stones, with 95 (43.6%) of the renal stones located in the lower pole. The single-treatment success rates for ureteral and renal stones were 62.3% and 68.8%, respectively. On univariate analysis, predictors of SWL success, regardless of stone location, were age (p = 0.01), BMI (p = 0.01), stone size (p < 0.01), MSD (p < 0.01) and SSD (p < 0.01). On multivariate analysis, MSD >900 HU (OR = 0.49, CI: 0.32-0.75) and SSD >110 mm (OR = 0.49, CI: 0.31-0.78) were both significant predictors of outcome. We have identified in a large series of renal and ureteric calculi that both MSD and SSD can reliably predict SWL outcomes. This data can be used in combination with other patient and stone-related factors to facilitate optimal treatment-based decisions and provide patients with more accurate single-treatment success rates for SWL.

Conspicuity of renal calculi at unenhanced CT: effects of calculus composition and size and CT technique.

PubMed

Tublin, Mitchell E; Murphy, Michael E; Delong, David M; Tessler, Franklin N; Kliewer, Mark A

2002-10-01

To determine the effects of calculus size, composition, and technique (kilovolt and milliampere settings) on the conspicuity of renal calculi at unenhanced helical computed tomography (CT). The authors performed unenhanced CT of a phantom containing 188 renal calculi of varying size and chemical composition (brushite, cystine, struvite, weddellite, whewellite, and uric acid) at 24 combinations of four kilovolt (80-140 kV) and six milliampere (200-300 mA) levels. Two radiologists, who were unaware of the location and number of calculi, reviewed the CT images and recorded where stones were detected. These observations were compared with the known positions of calculi to generate true-positive and false-positive rates. Logistic regression analysis was performed to investigate the effects of stone size, composition, and technique and to generate probability estimates of detection. Interobserver agreement was estimated with kappa statistics. Interobserver agreement was high: the mean kappa value for the two observers was 0.86. The conspicuity of stone fragments increased with increasing kilovolt and milliampere levels for all stone types. At the highest settings (140 kV and 300 mA), the detection threshold size (ie, the size of calculus that had a 50% probability of being detected) ranged from 0.81 mm + 0.03 (weddellite) to 1.3 mm + 0.1 (uric acid). Detection threshold size for each type of calculus increased up to 1.17-fold at lower kilovolt settings and up to 1.08-fold at lower milliampere settings. The conspicuity of small renal calculi at CT increases with higher kilovolt and milliampere settings, with higher kilovolts being particularly important. Small uric acid calculi may be imperceptible, even with maximal CT technique.

Efficacy of percutaneous treatment of biliary tract calculi using the holmium:YAG laser.

PubMed

Hazey, J W; McCreary, M; Guy, G; Melvin, W S

2007-07-01

Few Western studies have focused on percutaneous techniques using percutaneous transhepatic choledochoscopy (PTHC) and holmium:yttrium-aluminum-garnet (YAG) laser to ablate biliary calculi in patients unable or unwilling to undergo endoscopic or surgical removal of the calculi. The authors report the efficacy of the holmium:YAG laser in clearing complex biliary calculi using percutaneous access techniques. This study retrospectively reviewed 13 non-Asian patients with complex secondary biliary calculi treated percutaneously using holmium:YAG laser. Percutaneous access was accomplished via left, right, or bilateral hepatic ducts and upsized for passage of a 7-Fr video choledochoscope. Lithotripsy was performed under choledochoscopic vision using a holmium:YAG laser with 200- or 365-microm fibers generating 0.6 to 1.0 joules at 8 to 15 Hz. Patients underwent treatment until stone clearance was confirmed by PTHC. Downsizing and subsequent removal of percutaneous catheters completed the treatment course. Seven men and six women with an average age of 69 years underwent treatment. All the patients had their biliary tract stones cleared successfully. Of the 13 patients, 3 were treated solely as outpatients. The average length of percutaneous access was 108 days. At this writing, one patient still has a catheter in place. The average number of holmium:YAG laser treatments required for stone clearance was 1.6, with no patients requiring more than 3 treatments. Of the 13 patients, 8 underwent a single holmium:YAG laser treatment to clear their calculi. Prior unsuccessful attempts at endoscopic removal of the calculi had been experienced by 7 of the 13 patients. Five patients underwent percutaneous access and subsequent stone removal as their sole therapy for biliary stones. Five patients were cleared of their calculi after percutaneous laser ablation of large stones and percutaneous basket retrieval of the remaining stone fragments. There was one complication of pain requiring admission, and no deaths. The use of PTHC with holmium:YAG laser ablation is safe and efficacious, but requires prolonged biliary access and often multiple procedures to ensure clearance of all calculi.

Guidelines for TxDOT in selecting seal coat materials.

DOT National Transportation Integrated Search

2017-02-01

Aggregates used for seal coats should consist essentially of a single-size stone. When : determining binder application rates in the field, achieving an embedment depth of the stone into : the asphalt binder of about 40 to 50 percent is the goal. If ...

Testing and Evaluation of Large Stone Mixes Using Marshall Mix Design Procedures

DOT National Transportation Integrated Search

1989-11-01

Premature rutting of heavy duty asphalt pavements has been increasingly experienced in recent years primarily due to high pressure truck tires and increased wheel loads. Many asphalt technologists believe that the use of large size stone (maximum siz...

Pneumatic versus laser ureteroscopic lithotripsy: a comparison of initial outcomes and cost.

PubMed

Demir, Aslan; Karadağ, Mert Ali; Ceçen, Kurşat; Uslu, Mehmet; Arslan, Omer Erkam

2014-11-01

To audit the cost of laser versus pneumatic semirigid ureteroscopic lithotripsy and to analyze their relative initial outcomes and cost. Hundred and eighty-seven patients who underwent semirigid ureteroscopic lithotripsy were analyzed retrospectively in terms of age and sex of the patients; location and size of the stones; the type of probe and ancillary equipment such as guide wire, basket catheter, JJ stent requirements; irrigation amount; operation time; the cost of the anesthesia and further treatments such as a JJ stent removal operation and shock wave lithotripsy requirements and their costs. Two groups were formed based on this type of lithotripters, pneumatic and laser lithotripsy. Operation times (min.) in terms of the stone size, for stones <100 and >100 mm(2) were 20.75 ± 10.78 and 25.82 ± 14.23, respectively (p = 0.007). Operation times for the pneumatic and laser groups were 33.05 ± 11.36 and 15.25 ± 6.14, respectively (p < 0.05).The stone-free rates for pneumatic and laser groups were 89.6 % (n = 69) and 98.2 % (n = 108), respectively (p = 0.01). The mean cost of the operations for each of the study groups was 261.5 ± 66.13 and 311.7 ± 51.97 US$, respectively (p = 0.001). The mean cost in terms of the stone size, for stones <100 and >100 mm(2), was 272.86 ± 53.05 and 323.71 ± 66.88 US$, respectively (p = 0.01). It seems that usage of laser lithotripsy (LL) in patients with ureteral stones is more effective than pneumatic lithotripsy (PL) in terms of operation time and SF rate. On the other hand, the mean cost of LL seems to be more expensive than PL. Urologists should think these parameters before the choice of these two treatment modalities. The higher the effectiveness, the greater the cost.

Wild capuchin monkeys spontaneously adjust actions when using hammer stones of different mass to crack nuts of different resistance.

PubMed

Liu, Qing; Fragaszy, Dorothy M; Visalberghi, Elisabetta

2016-09-01

Expert tool users are known to adjust their actions skillfully depending on aspects of tool type and task. We examined if bearded capuchin monkeys cracking nuts with stones of different mass adjusted the downward velocity and the height of the stone when striking palm nuts. During a field experiment carried out in FBV (Piauí, Brazil), eight adult wild capuchin monkeys (five males) cracked Orbygnia nuts of varied resistance with hammer stones differing in mass. From recorded videos, we identified the highest strike per nut-cracking episode, and for this strike, we calculated the height to which the monkey lifted the stone, the maximum velocity of the stone during the downward phase, the work done on the stone, and the kinetic energy of the strike. We found that individual capuchins achieved average maximum kinetic energy of 8.7-16.1 J when using stones between 0.9 and 1.9 kg, and maximum kinetic energy correlated positively with mass of the stone. Monkeys lifted all the stones to an individually consistent maximum height but added more work to the stone when using lighter stones. One male and one female monkey lifted stones higher when they cracked more resistant nuts. The high resistance of the Orbygnia nut elicits production of maximum kinetic energy, which the monkeys modulate to some degree by adding work to lighter stones. Capuchin monkeys, like chimpanzees, modulate their actions in nut-cracking, indicating skilled action, although neither species regulates kinetic energy as precisely as skilled human stone knappers. Kinematic analyses promise to yield new insights into the ways and extent to which nonhuman tool users develop expertise. Am J Phys Anthropol 161:53-61, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Prevalence of Coronal Pulp Stones and Its Relation with Systemic Disorders in Northern Indian Central Punjabi Population

PubMed Central

Bains, Sandeep Kumar; Bhatia, Archana; Singh, Harkanwal Preet; Biswal, Swati Swagatika; Kanth, Shashi; Nalla, Srinivas

2014-01-01

Aim. To estimate the prevalence of coronal pulp stones in the molar teeth of dental outpatients of Sunam, Sangrur district, Punjab, India, to report any association between occurrence of pulp stones with age, gender, dental arch, side, and dental status and to find out correlation between pulp stones with dental and systemic diseases. Materials and Methods. 500 routine dental outpatients within age group of 18–67 years were involved in the study. Molar bitewing of left and right side of each patient was taken with XCP bitewing instrument and size 2 film. The presence or absence of pulp stones was recorded. Chi-square analysis was used to record the prevalence of pulp stones and to compare it with demographic and systemic factors. Results. Overall prevalence of pulp stones was 41.8%. Pulp stones were significantly higher in maxilla (11.59%) than mandible (6.54%), left side than right side, and first molar than other molars. Higher numbers of pulp stones were recorded in patients with cardiovascular disease (38.89%) than with cholelithiasis and renal lithiasis. Conclusion. Pulp stones were higher in maxillary arch than mandibular arch and in females than males. Cardiovascular patients had higher number of pulp stones than other groups. PMID:24944821

Solo Sonographically Guided PCNL under Spinal Anesthesia: Defining Predictors of Success.

PubMed

Nouralizadeh, Akbar; Pakmanesh, Hamid; Basiri, Abbas; Aayanifard, Mohammad; Soltani, Mohammad Hossein; Tabibi, Ali; Sharifiaghdas, Farzaneh; Ziaee, Seyed Amir Mohsen; Shakhssalim, Naser; Valipour, Reza; Narouie, Behzad; Radfar, Mohammad Hadi

2016-01-01

Aim. Sonography has been brought in percutaneous nephrolithotripsy (PCNL) as an adjunct to or substitute for X-ray to restrict radiation exposure. This study was designed to investigate the possible predictors for the success of the solo sonographically guided PCNL. Methods. 148 consecutive cases were prospectively enrolled. All steps of PCNL were performed solely with sonography guidance under spinal anesthesia. Residual stones were evaluated the day after surgery using sonography and plain radiography. Results. The mean age was 46 ± 15 years; 40% of kidneys had hydronephrosis. The mean stone burden was 504 ± 350 mm(2). The mean duration of surgery was 43 ± 21 minutes. The early stone-free rate was 92% in inferior or middle calyceal stones, 89.5% in single pelvic stones, 81.5% in partial staghorn stones, and 61.9% in staghorn stones. The mean residual stone size was 13 ± 8 mm. Logistic regression showed that a lower age and a larger stone burden significantly predicted positive residual stones. Fifteen percent of patients presented with grade I or II and six percent showed grade III complication based on Clavien classification. There was no cases of organ injury or death. Conclusion. Solo ultrasonographically guided PCNL under spinal anesthesia is feasible with an acceptable stone-free rate and complication rate.

Management of cystinuric patients: an observational, retrospective, single-centre analysis.

PubMed

Ahmed, Kamran; Khan, Mohammad Shamim; Thomas, Kay; Challacombe, Ben; Bultitude, Matthew; Glass, Jonathan; Tiptaft, Richard; Dasgupta, Prokar

2008-01-01

A critical appraisal of the management of patients with cystine stones treated in our unit in the past 6 years and to analyze the outcome of multimodality therapies. An observational, single-centre retrospective study. We reviewed the records of all patients with stones referred to our centre over a 6-year period from 1998 to 2005. Data recorded included demographic details, medical therapies received/prescribed, compliance with medical therapies, mode of treatment, stone clearance and any recurrence during this period of study. A total of 30 cystinuric patients were treated in our institution over the period of 6 years from 1998 to early 2005. Of these 16 were males and 14 females with an average age at last follow-up of 39 years (range 15-70). Two patients were successfully managed medically. The remaining patients (n = 28) underwent a total of 237 procedures (pre- and postreferral to our unit), with an average of 7.9 procedures per patient for 126 stone episodes (4.2 episodes/patient). The modes of treatment included extracorporeal shockwave lithotripsy (n = 143), ureterorenoscopy and intracorporeal lithotripsy (n = 50), percutaneous nephrolithotomy (n = 28) and open procedures (n = 16). Two patients needed open surgery at our unit. Prior to referral to our dedicated unit, patients had received treatment with extracorporeal shockwave lithotripsy (multiple sessions), ureteroscopy (n = 14), percutaneous nephrolithotomy (n = 4) and open stone removal (n = 14). Most of the stones at our unit were managed using minimally invasive therapies. Compliance of cystinuric patients with medical treatment is often poor and patients experience recurrent stone episodes requiring multiple interventions. Modern management of cystine calculi should be with staged minimally invasive procedures to avoid the complications of multiple open procedures wherever possible along with appropriate medical prophylaxis.

CT visible internal stone structure, but not Hounsfield unit value, of calcium oxalate monohydrate (COM) calculi predicts lithotripsy fragility in vitro.

PubMed

Zarse, Chad A; Hameed, Tariq A; Jackson, Molly E; Pishchalnikov, Yuri A; Lingeman, James E; McAteer, James A; Williams, James C

2007-08-01

Calcium oxalate monohydrate (COM) stones are often resistant to breakage using shock wave (SW) lithotripsy. It would be useful to identify by computed tomography (CT) those COM stones that are susceptible to SW's. For this study, 47 COM stones (4-10 mm in diameter) were scanned with micro CT to verify composition and also for assessment of heterogeneity (presence of pronounced lobulation, voids, or apatite inclusions) by blinded observers. Stones were then placed in water and scanned using 64-channel helical CT. As with micro CT, heterogeneity was assessed by blinded observers, using high-bone viewing windows. Then stones were broken in a lithotripter (Dornier Doli-50) over 2 mm mesh, and SW's counted. Results showed that classification of stones using micro CT was highly repeatable among observers (kappa = 0.81), and also predictive of stone fragility. Stones graded as homogeneous required 1,874 +/- 821 SW/g for comminution, while stones with visible structure required half as many SW/g, 912 +/- 678. Similarly, when stones were graded by appearance on helical CT, classification was repeatable (kappa = 0.40), and homogeneous stones required more SW's for comminution than did heterogeneous stones (1,702 +/- 993 SW/g, compared to 907 +/- 773). Stone fragility normalized to stone size did not correlate with Hounsfield units (P = 0.85). In conclusion, COM stones of homogeneous structure require almost twice as many SW's to comminute than stones of similar mineral composition that exhibit internal structural features that are visible by CT. This suggests that stone fragility in patients could be predicted using pre-treatment CT imaging. The findings also show that Hounsfield unit values of COM stones did not correlate with stone fragility. Thus, it is stone morphology, rather than X-ray attenuation, which correlates with fragility to SW's in this common stone type.

Application of ureterorenoscope and flexible ureterorenoscope lithotripsy in removing calculus from extracorporeal living donor renal graft: a single-center experience.

PubMed

Lin, Chun-Hua; Zhang, Zuo-Fu; Wang, Jiahui; Yu, Lu-Xin; Wang, Wen-Ting; Shi, Lei; Lin, Xiang-Nan

2017-11-01

Here, we reported our clinical application of ureterorenoscope (URS) and flexible URS lithotripsy in stone removal on 10 cases of excised living donor kidney graft. After the extraction of donor kidney by retroperitoneal laparoscopy, the donor graft was perfused with 4 °C HCA solution. Calculus between 2-4 mm were removed intact with lithotomy forceps under direct vision of URS. Larger calculi of >4 mm were fractured with flexible URS combining holmium laser lithotripsy. Fragments of the calculus were extracted with basket extractor and lithotomy forceps. All operations were successful. The operation time was 14-31 min (average 21.2 ± 6.3 min). The kidneys were then transplanted to the recipients using routine procedure. The transplanted kidneys functioned well after transplantation. Gross hematuria resolved 1-4 d after operation (average 2.6 ± 0.9 d). The transplanted kidneys functioned well without early complications such as functional recovery delay and acute graft rejection. The donors and recipients were followed for 12 months. The size of the transplanted kidneys was normal and new stones or urinary obstruction was not seen upon urinary color Doppler ultrasound examination. In conclusion, we believe it is feasible, safe and effective to use URS or flexible URS combining holmium laser lithotripsy on extracorporeal living donor kidney.

[Effect of the body mass index on outcomes of ureterorenoscopy for renal stones].

PubMed

Schott, F; Knipper, S; Orywal, A K; Gross, A J; Netsch, C

2016-11-01

Purpose of this work is to compare the outcome of ureterorenoscopy (URS) with regard to stone-free rates (SFR) and complication rates (CR) in patients with different body mass index (BMI) scores for the treatment of kidney stones. A retrospective chart review of all patients with known BMI, who underwent URS for kidney stones between 2006 and 2012 at our institution, was performed (n = 556 patients). The SFR and CR of obese patients were compared to overweight and normal weight patients. Mean age was 52.51 years and the average BMI 27.74 kg/m 2 . Of the patients, 34.2 % had normal weight (22.59 ± 1.91 kg/m 2 ), 39.6 % were overweight (27.30 ± 1.42 kg/m 2 ), and 26.3 % were obese (35.09 ± 5.93 kg/m 2 ). The mean ASA score differed significantly between normal weight (1.99 ± 0.57), overweight (2.03 ± 0.62), and obese (2.22 ± 0.63) patients (p ≤ 0.036). The mean stone size was 8.51 ± 6.84 mm and the mean number of stones per patient 1.9 ± 2.41, whereby the differences between groups was not significant. There were no differences between the groups regarding the use of preoperative (94.8 %) and postoperative ureteral stents (60.3 %), the Ho:YAG laser (33.6 %), the use of flexible (16.2 %) or semirigid/flexible URS (59.4 %), and the mean operative time (52.04 ± 34.55 min). There were no differences in the SFR for the upper (90 %), mid (94.7 %), and lower pole (90.2 %), multiple location (68.6 %) or the total SFR (86.3 %). Total SFR of 95.7, 88.4, and 73.7 % for urinary calculi < 5 mm, 5-9 mm, and ≥ 10 mm, respectively, were found and the differences between the patient groups was not significant. The CR was 10.4 % (differences between the patient groups not significant). URS is an appropriate treatment for renal stones with high SFR and low CR regardless of patient's BMI.

Extracorporeal shockwave lithotripsy in infants.

PubMed

Ramakrishnan, Prem A; Medhat, Mohammed; Al-Bulushi, Younis H; Nair, Priti; Al-Kindy, Ahmed

2007-10-01

Pediatric urolithiasis is relatively uncommon and limited information is available on the application of minimally invasive management modalities in young children. We present a single centre experience with extracorporeal shockwave lithotripsy (ESWL) for infants with upper urinary tract calculi. A total of 74 infants aged 3 months to 24 months with upper urinary tract calculi were treated with ESWL under general anesthesia using the Wolf 2500 and the 2501 Piezolith lithotriptors over a 14 and a half-year period. Patient and stone characteristics, risk factors for urolithiasis, treatment parameters, clinical outcomes and long-term follow-up were assessed and recorded. The mean patient age was 14.5 (range 3 to 24) months. The mean renal stone size was 18.2 (range 7 to 32) mm while the mean ureteral stone size was 9.4 (range 5 to 14) mm. Metabolic abnormalities, structural anomalies and urinary tract infections were identified as contributory factors for stone formation in 34% of the infants. At the 3-month follow-up there was an overall successful outcome in 72 infants (97%) that included 65 (88%) who were rendered stone-free and 7 (9%) who had clinically insignificant stone fragments. Retreatment was required in 27 (35%) patients, auxiliary procedures after ESWL were needed in 5 (7%) and secondary operative procedures were required in 2 (3%). Major complications were encountered in 5 (7%) patients that included complete ureteral obstruction with sepsis in 2, partial ureteral obstruction in 1 and febrile urinary tract infection in 2 other children. Long-term follow-up was recorded in 39 infants: 8 developed recurrent stones, 2 had stone regrowth and 1 developed mild hypertension but none had significant deterioration of renal function. ESWL is an effective treatment for upper urinary tract calculi in infants. In the short-term, complications are minimal but long-term follow-up is important.

Shock wave lithotripsy outcomes for lower pole and non-lower pole stones from a university teaching hospital: Parallel group comparison during the same time period

PubMed Central

Geraghty, Robert; Burr, Jacob; Simmonds, Nick; Somani, Bhaskar K.

2015-01-01

Introduction: Shock wave lithotripsy (SWL) is a treatment option for all locations of renal and ureteric stones. We compared the results of SWL for lower pole renal stones with all other non-lower pole renal and ureteric stones during the same time period. Material and Methods: All SWL procedures were carried out as day case procedures by a mobile lithotripter from January 2012 to August 2013. The follow-up imaging was a combination of KUB X-ray or USS. Following SWL treatment, the stone free rate (SFR) was defined as ≤3 mm fragments. Results: A total of 148 patients with a mean age of 62 years underwent 201 procedures. Of the 201 procedures, 93 (46%) were for lower pole stones. The non-lower pole stones included upper pole (n = 36), mid pole (n = 40), renal pelvis (n = 10), PUJ (n = 8), mid ureter (n = 3), upper ureter (n = 5) and a combination of upper, middle and/or lower pole (n = 6). The mean stone size for lower pole stones (7.4 mm; range: 4-16 mm) was slightly smaller than non-lower pole stones (8 mm; range: 4-17 mm). The stone fragmentation was successful in 124 (62%) of patients. However, the SFR was statistically significantly better (P = 0.023) for non-lower pole stones 43 (40%) compared to lower pole stones 23 (25%). There were 9 (4%) minor complications and this was not significantly different in the two groups. Conclusions: Although SWL achieves a moderately high stone fragmentation rate with a low complication rate, the SFR is variable depending on the location of stone and the definition of SFR, with lower pole stones fairing significantly worse than stones in all other locations. PMID:25657543

Shock wave lithotripsy outcomes for lower pole and non-lower pole stones from a university teaching hospital: Parallel group comparison during the same time period.

PubMed

Geraghty, Robert; Burr, Jacob; Simmonds, Nick; Somani, Bhaskar K

2015-01-01

Shock wave lithotripsy (SWL) is a treatment option for all locations of renal and ureteric stones. We compared the results of SWL for lower pole renal stones with all other non-lower pole renal and ureteric stones during the same time period. All SWL procedures were carried out as day case procedures by a mobile lithotripter from January 2012 to August 2013. The follow-up imaging was a combination of KUB X-ray or USS. Following SWL treatment, the stone free rate (SFR) was defined as ≤3 mm fragments. A total of 148 patients with a mean age of 62 years underwent 201 procedures. Of the 201 procedures, 93 (46%) were for lower pole stones. The non-lower pole stones included upper pole (n = 36), mid pole (n = 40), renal pelvis (n = 10), PUJ (n = 8), mid ureter (n = 3), upper ureter (n = 5) and a combination of upper, middle and/or lower pole (n = 6). The mean stone size for lower pole stones (7.4 mm; range: 4-16 mm) was slightly smaller than non-lower pole stones (8 mm; range: 4-17 mm). The stone fragmentation was successful in 124 (62%) of patients. However, the SFR was statistically significantly better (P = 0.023) for non-lower pole stones 43 (40%) compared to lower pole stones 23 (25%). There were 9 (4%) minor complications and this was not significantly different in the two groups. Although SWL achieves a moderately high stone fragmentation rate with a low complication rate, the SFR is variable depending on the location of stone and the definition of SFR, with lower pole stones fairing significantly worse than stones in all other locations.

Cholecystectomy for Prevention of Recurrence after Endoscopic Clearance of Bile Duct Stones in Korea.

PubMed

Song, Myung Eun; Chung, Moon Jae; Lee, Dong Jun; Oh, Tak Geun; Park, Jeong Youp; Bang, Seungmin; Park, Seung Woo; Song, Si Young; Chung, Jae Bock

2016-01-01

Cholecystectomy in patients with an intact gallbladder after endoscopic removal of stones from the common bile duct (CBD) remains controversial. We conducted a case-control study to determine the risk of recurrent CBD stones and the benefit of cholecystectomy for prevention of recurrence after endoscopic removal of stones from the CBD in Korean patients. A total of 317 patients who underwent endoscopic CBD stone extraction between 2006 and 2012 were included. Possible risk factors for the recurrence of CBD stones including previous cholecystectomy history, bile duct diameter, stone size, number of stones, stone composition, and the presence of a periampullary diverticulum were analyzed. The mean duration of follow-up after CBD stone extraction was 25.4±22.0 months. A CBD diameter of 15 mm or larger [odds ratio (OR), 1.930; 95% confidence interval (CI), 1.098 to 3.391; p=0.022] and the presence of a periampullary diverticulum (OR, 1.859; 95% CI, 1.014 to 3.408; p=0.045) were independent predictive factors for CBD stone recurrence. Seventeen patients (26.6%) in the recurrence group underwent elective cholecystectomy soon after endoscopic extraction of CBD stones, compared to 88 (34.8%) in the non-recurrence group; the difference was not statistically significant (p=0.212). A CBD diameter of 15 mm or larger and the presence of a periampullary diverticulum were found to be potential predictive factors for recurrence after endoscopic extraction of CBD stones. Elective cholecystectomy after clearance of CBD stones did not reduce the incidence of recurrent CBD stones in Korean patients.

Big Creek Flood Control Project, Cleveland, Ohio. Phase II. General Design Memorandum. Appendix B. Alternative Studies.

DTIC Science & Technology

1978-11-01

120, Engineering and Design Additional Guidance for Riprap Channel Protection. Good qual- ity stone is available in the Cleveland area; therefore, it...design life. The galvanizing is subject to abrasion and deterioration. As the gabions would be filled with stone that would have the same quality of...riprap, the PVC coated gabions would provide protection in excess of 50 years without anticipated maintenance. As the stone size for all gabions is

Ultrasonic propulsion of kidney stones: preliminary results of human feasibility study.

PubMed

Bailey, Michael; Cunitz, Bryan; Dunmire, Barbrina; Paun, Marla; Lee, Franklin; Ross, Susan; Lingeman, James; Coburn, Michael; Wessells, Hunter; Sorensen, Mathew; Harper, Jonathan

2014-09-03

One in 11 Americans has experienced kidney stones, with a 50% average recurrence rate within 5-10 years. Ultrasonic propulsion (UP) offers a potential method to expel small stones or residual fragments before they become a recurrent problem. Reported here are preliminary findings from the first investigational use of UP in humans. The device uses a Verasonics ultrasound engine and Philips HDI C5-2 probe to generate real-time B-mode imaging and targeted "push" pulses on demand. There are three arms of the study: de novo stones, post-lithotripsy fragments, and the preoperative setting. A pain questionnaire is completed prior to and following the study. Movement is classified based on extent. Patients are followed for 90 days. Ten subjects have been treated to date: three de novo , five post-lithotripsy, and two preoperative. None of the subjects reported pain associated with the treatment or a treatment related adverse event, beyond the normal discomfort of passing a stone. At least one stone was moved in all subjects. Three of five post-lithotripsy subjects passed a single or multiple stones within 1-2 weeks following treatment; one subject passed two (1-2 mm) fragments before leaving clinic. In the pre-operative studies we successfully moved 7 - 8 mm stones. In four subjects, UP revealed multiple stone fragments where the clinical image and initial ultrasound examination indicated a single large stone.

Is pre-operative imaging essential prior to ureteric stone surgery?

PubMed

Youssef, F R; Wilkinson, B A; Hastie, K J; Hall, J

2012-09-01

The aim of this study was to identify patients not requiring ureteric stone surgery based on pre-operative imaging (within 24 hours) prior to embarking on semirigid ureteroscopy (R-URS) for urolithiasis. The imaging of all consecutive patients on whom R-URS for urolithiasis was performed over a 12-month period was reviewed. All patients had undergone a plain x-ray of the kidney, ureters and bladder (KUB), abdominal non-contrast computed tomography (NCCT-KUB) or both on the day of surgery. A total of 96 patients were identified for the study. Stone sizes ranged from 3 mm to 20 mm. Thirteen patients (14%) were cancelled as no stone(s) were identified on pre-operative imaging. Of the patients cancelled, 8 (62%) required NCCT-KUB to confirm spontaneous stone passage. One in seven patients were stone free on the day of surgery. This negates the need for unnecessary anaesthetic and instrumentation of the urinary tract, with the associated morbidity. Up-to-date imaging prior to embarking on elective ureteric stone surgery is highly recommended.

Primary in situ extracorporeal shock wave lithotripsy in the management of ureteric calculi: results with a third-generation lithotripter.

PubMed

Gnanapragasam, V J; Ramsden, P D; Murthy, L S; Thomas, D J

1999-11-01

To review the results of primary in situ extracorporeal shock wave lithotripsy (ESWL) for the treatment of ureteric stones using a third-generation lithotripter, the Dornier MFL 5000 (Dornier Medizentechnic, Germany). The study comprised a retrospective review of treatment outcome in 180 patients with 196 stones who were treated with primary in situ ESWL, assessing the success of this approach and establishing reasons for failure. At the 3-month follow-up, 88% of patients were stone-free; 21 patients failed ESWL and were treated by ureteroscopic stone extraction with no complications. Stone-free rates were 90% for upper ureteric, 89% for middle-third and 86% for lower-third calculi. Twenty-one patients required auxiliary procedures in the form of JJ stenting or nephrostomy. Failure of ESWL was associated with stone size (>1.3 cm) but not location or inadequate treatment. Where prompt access to ESWL is available, primary in situ ESWL remains an effective form of treatment for all ureteric calculi, although stone-free rates are lower for larger stones.

Cystinuria-a urologist's perspective.

PubMed

Thomas, Kay; Wong, Kathie; Withington, John; Bultitude, Matthew; Doherty, Angela

2014-05-01

Cystinuria is a genetic disease that leads to frequent formation of stones. In patients with recurrent stone formation, particularly patients <30 years old or those who have siblings with stone disease, urologists should maintain a high index of suspicion of the diagnosis of cystinuria. Patients with cystinuria require frequent follow-up and a multidisciplinary approach to diagnosis, prevention and management. Patients have reported success in preventing stone episodes by maintaining dietary changes using a tailored review from a specialist dietician. For patients who do not respond to conservative lifestyle measures, medical therapy to alkalinize urine and thiol-binding drugs can help. A pre-emptive approach to the surgical management of cystine stones is recommended by treating smaller stones with minimally invasive techniques before they enlarge to a size that makes management difficult. However, a multimodal approach can be required for larger complex stones. Current cystinuria research is focused on methods of monitoring disease activity, novel drug therapies and genotype-phenotype studies. The future of research is collaboration at a national and international level, facilitated by groups such as the Rare Kidney Stone Consortium and the UK Registry of Rare Kidney Diseases.

Percutaneous suprapubic stone extraction for posterior urethral stones in children: efficacy and safety.

PubMed

Safwat, Ahmed S; Hameed, Diaa A; Elgammal, Mohamed A; Abdelsalam, Yasser M; Abolyosr, Ahmad

2013-08-01

To evaluate the safety and efficacy of percutaneous suprapubic stone extraction (PSPSE) for pediatric posterior urethral stones. Between July 2007 and June 2010, 54 boys presenting with acute urinary retention due to posterior urethral stones underwent PSPSE. Patients were a mean age of 66.4 months (range, 8-180 months). The stone size was 0.7-1.9 cm. Patients were placed under general anesthesia, and a 7F urethroscope was used to pushback the stone to the bladder. A 3-mm suprapubic puncture with a scalpel was performed, followed by insertion of a straight narrow hemostat through the puncture aided with cystoscopic guidance. The stone was grasped with the hemostat in its narrowest diameter and was extracted percutaneously or crushed if friable. The suprapubic puncture was closed with a single 4-0 Vicryl (Ethicon) suture. Intact stone retrieval was achieved in 45 patients, and the stone was crushed into minute fragments in 9 patients. Intraperitoneal extravasation developed in 1 patient that required open surgical intervention. Mean operative time was 22 minutes. Patients were monitored for up to 17 months, with complete resolution of symptoms and stone clearance. PSPSE provides a minimally invasive approach for the extraction of urethral and bladder stones in the pediatric population. The use of a straight hemostat for suprapubic stone extraction or crushing is a good alternative to suprapubic tract dilation, with minimal morbidity. Copyright © 2013 Elsevier Inc. All rights reserved.

How effective is ureteroscopy in the treatment of pediatric stone disease?

PubMed

Thomas, John C

2010-08-01

Pediatric ureteroscopy has been increasingly used to manage both ureteral and renal stones. Unfortunately, there are no current standardized recommendations when treating pediatric stone disease so the modality chosen is left to the treating surgeon. A review of the current literature on pediatric ureteroscopy was used to compile this article. For the purposes of this review, the majority of series include stones < or =1 cm. Ureteroscopy is considered to be first-line therapy in treating mid- to distal ureteral stones and is rapidly evolving as an acceptable first-line therapy for renal stones as well. Limitations do exist and include stone composition, location, size, as well as the unique anatomic challenges faced by pediatric urologists in terms of anomalous kidneys and/or reconstructed urinary tracts. In conclusion, ureteroscopy can be considered first-line therapy for mid- or distal ureteral stones, however, it shares a similar efficacy rate as extracorporeal shock wave lithotripsy for the treatment of renal calculi. There is a need for direct comparison in the literature of all modalities treating pediatric stone disease to facilitate guidelines that help treating surgeons choose the most efficacious modality offering the highest success rates with the lowest morbidity.

Comparative Evaluation of 4-Inch and 6-Inch Diameter Specimens for Testing Large Stone Asphalt Mixes

DOT National Transportation Integrated Search

1990-01-01

Increased incidence of premature rutting of heavy duty asphalt pavements has : been experienced in recent years. There is a general agreement among most : asphalt paving technologists that the use of large size stone in the binder and : base courses ...

Challenging Case: Stones.

PubMed

Soloway, Mark S; Ziemba, Justin B; Matlaga, Brian R; Monga, Manoj

2016-10-01

A 40-year-old woman presents to the emergency department after a motor vehicle accident, and a CT scan revealed no injuries but incidentally notes three non-obstructing stones in the left kidney of 3, 4, and 5 mm in size. She is completely asymptomatic and has no history of urolithiasis.

Geochemistry of CI chondrites: Major and trace elements, and Cu and Zn Isotopes

NASA Astrophysics Data System (ADS)

Barrat, J. A.; Zanda, B.; Moynier, F.; Bollinger, C.; Liorzou, C.; Bayon, G.

2012-04-01

In order to check the heterogeneity of the CI chondrites and determine the average composition of this group of meteorites, we analyzed a series of six large chips (weighing between 0.6 and 1.2 g) of Orgueil prepared from five different stones. In addition, one sample from each of Ivuna and Alais was analyzed. Although the sizes of the chips used in this study were “large”, our results show evidence for minor chemical heterogeneity in Orgueil, particularly for alkali elements and U. After removal of one outlier sample, the spread of the results is considerably reduced. For most of the 46 elements analyzed in this study, the average composition calculated for Orgueil is in very good agreement with previous CI estimates. This average, obtained with a “large” mass of samples, is analytically homogeneous and is suitable for normalization purposes. Finally, the Cu and Zn isotopic ratios are homogeneously distributed within the CI parent body with a spread of less than 100 ppm per atomic mass unit (amu).

Effect of urine pH on the effectiveness of shock wave lithotripsy: A pilot study.

PubMed

Majzoub, Ahmad; Al-Ani, Ammar; Gul, Tawiz; Kamkoum, Hatem; Al-Jalham, Khalid

2016-01-01

Shock wave lithotripsy (SWL) is a well-established modality in the treatment of urolithiasis. Studying the effect of urine pH on SWL success is appealing as pH can be manipulated before SWL to insure a better outcome. This is a prospective study performed at a tertiary medical center. Patients presenting to the SWL unit with a single renal stone <2 cm in size were included in this study. In addition to standard laboratory and radiologic investigations, urine pH measurement was performed on all patients before their procedure. The number of sessions performed, and the stone-free rate (SFR) were assessed. Patients were divided into two groups according to stone clearance. Group 1 was stone-free, whereas Group 2 had residual stones after three sessions of SWL. Data was also classified according to different pH ranges. Influential factors were compared among the study groups and pH ranges. A total of 175 patients were included in this study. The SFR was 54.3%. The mean number of sessions performed was 2.2 ± 0.8. Group 1 included 95 patients, whereas Group 2 had eighty patients. Among all studied factors, stone size (P = 0.03) and skin to stone distance (P = 0.04) significantly affected SFR with SWL. Urine pH was not found to have a statistically significant influence on SWL outcome (P = 0.51). Urine pH was not found in this study population to influence the effectiveness of SWL. Further experimental studies are required to help investigate this notion.

Early Experience Of Pneumatic Lithoclast For The Management Of Ureteric Stones At Peshawar.

PubMed

Nawaz, Ahmad; Wazir, Bakhtawar Gul; Orakzai, Akhtar Nawaz

2016-01-01

Pakistan lies in the Afro-Asia stone belt. Ureteric calculi are common occurrence and a major burden on health care facilities in Pakistan. The objective of this study was to assess the efficacy and safety of pneumatic lithoclast in the management of ureteric calculi. Case series study Department of Urology at Institute of Kidney Diseases Hayatabad Peshawar, from 1st Oct 2010 to 1st Oct 2011. One-hundred adult patients with ureteric calculi ≥ 0.7 cm were evaluated by history, physical examination, routine blood and urine examination after taking their written informed consent and approval of ethical committee. Ultrasound and X-ray KUB were done with IVU if required. All patients underwent ureteroscopy within intracorporeal lithotripsy and JJ stenting. Patients were followed up with post-op X-ray KUB at 24 hours and then weekly intervals till they became stone free. Following parameters were assessed: stone size, site, laterality, degree of fragmentation, success rate, stone migration and complications. Inability to reach the calculus with URS, proximal migration of stone or requirement of another/auxiliary procedure was considered failure. One hundred and ten patients were enrolled with a mean age of 38±10 years. There were 72 males and 28 females. Fifty-eight calculi were on right and 42 on left side. 24, 24 and 52 stones were in upper, middle and lower ureter respectively. Forty stones measured 7-10 mm, 52 measured 11-15 mm and 8 measured 16-20 mm in size. 98 stones were broken while 2 calculi migrated proximally. Overall success rate was 90% (Efficiency Quotient =78.95). Success rate in upper, middle and lower ureter was 83.3%, 83.3% and 96.1% respectively. 10 and 2 patients required ESWL and open ureterolithotomy, respectively, as additional treatment. Mean operative time was 33.5 minutes. There were no major complications.. Pneumatic lithoclast with URS is effective and safe in the management of the ureteric calculi with some limitations in the upper ureter.

Lessons from a Stone Farm

NASA Astrophysics Data System (ADS)

Kavanagh, John P.; Rao, P. Nagaraj

2007-04-01

The stone farm is a system for measuring macroscopic stone growth of 12 calcium stones simultaneously. It is based on mixed suspension, mixed product removal continuous crystallization principles and the stones are grown continuously for about 500 hours or more. The growth of the stones follows a surface area dependent pattern and the growth rate constants are very similar irrespective of whether the stating materials are fragments of human stone or pieces of marble chip. Increasing citrate from 2mM to 6mM caused a significant growth inhibition which persisted in the presence of urinary macromolecules. Phytate was a very effective inhibitor (about 50% at sub-μM concentrations) but the effective concentration was increased by an order of magnitude in the presence of urinary macromolecules. The effective concentration for inhibition in a crystallization assay was a further two orders of magnitude higher. Urinary macromolecules or almost whole urine were also strongly inhibitory although neither human serum albumin nor bovine mucin had any great effect. The relationship between the size distribution of crystals in suspension and the stone enlargement rate suggests that the primary enlargement mechanism for these in vitro stones is through aggregation. The stone farm is a powerful tool with which to study crystallization inhibitors in a new light. Some differences between inhibition of crystallization and inhibition of stone growth have emerged and we have obtained quantitative evidence on the mechanism of stone enlargement in vitro. Our findings suggest that the interface between crystals in suspension and the stone surface is the key to controlling stone enlargement.

Minimally invasive percutaneous nephrolithotomy in preschool age children with kidney calculi (including stones induced by melamine-contaminated milk powder).

PubMed

Yan, Xiang; Al-Hayek, Samih; Gan, Weidong; Zhu, Wei; Li, Xiaogong; Guo, Hongqian

2012-10-01

This study was undertaken to assess the safety and efficacy of minimally invasive percutaneous nephrolithotomy (mini-PCNL) using ureteroscope and pneumatic intracorporeal lithotripsy in preschool age children with kidney calculi. We studied 27 renal units in 20 patients of preschool age (≤ 6 years) who underwent mini-PCNL at our institute. The mean age was 42.6 months (range 14-68 months). The average stone burden was 1.85 cm (range 0.9-2.8 cm). Eight patients aged 14 to 58 months had been exposed to melamine-tainted powdered formula. The mini-PCNL was performed with an X-ray-guided peripheral puncture. Minimal tract dilatation was undertaken to fit a 14-16 Fr peel-away sheath. Ureteroscope and pneumatic intracorporeal lithotripsy were used to fragment the stones. Complete clearance was achieved in 23 renal units (85.2 %) with mini-PCNL monotherapy. This has increased to 92.6 % after adjunctive ESWL. The average fall in hemoglobin was 1.28 g/dL. None of the patients required blood transfusion. The median length of hospital stay was 8.2 days. Patients were followed up every 6 months for 2 years. There has been only one recurrence of stone and no long-term complications. Mini-PCNL is a effective treatment for pediatric kidney stones refractory to extracorporeal shock wave lithotripsy, including stones induced by melamine-contaminated milk powder. The "mini-PCNL" technique, which uses ureteroscope and pneumatic intracorporeal lithotripsy, is a safe and feasible modality for treating renal calculi in preschool age children.

Do JJ Stents Increase the Effectiveness of Extracorporeal Shock Wave Lithotripsy for Pediatric Renal Stones?

PubMed

Gündüz, Metin; Sekmenli, Tamer; Ciftci, İlhan; Elmacı, Ahmet Midhat

2017-01-01

We aimed to evaluate the effects of preoperative urinary catheterization in nephrolithiasis treatment with extracorporeal shock wave lithotripsy (SWL). Patients admitted to the Department of Pediatric Surgery for renal stones between June 2012 and June 2014 were evaluated retrospectively. Patients were divided into 2 groups based on JJ stent placements. Group 1 did not receive JJ stents, while group 2 did. The recorded demographic data for each group included age, gender, stone size, location, sessions, and complications. The Elmed Complit ESWL system was used with 11-13 kV, and 1,000-1,200 shots in patients 2-4 years of age, and 11-14 kV, and 1,000-1,500 shots for patients over 4 years. In group 1, 18 sessions of SWL were performed on 8 female and 2 male children with a mean age of 4.5 (range 2-12) years and stone diameter of 9 (range 7-15) mm. The locations of the renal stones were in the upper pole in 1 patient, 7 in the lower pole, and 2 in the pelvis renalis. Postoperatively, 1 patient had hematuria, 2 had dysuria, and one had a stone in the external urethral meatus. Eighty percent of patients were stone free; there were no fragmentations in 2 patients, and 1 patient discontinued treatment. In group 2, 15 SWL sessions were performed on 5 female and 5 male children aged 4 (range 3-5) and the stone diameter was 9 (range 7-16) mm. The locations of the renal stones were in the upper pole in 6 patients, in the lower pole in 3 patients, and in the ureteropelvic junction in one patient. JJ stents were placed in all patients preoperatively. Postoperatively, 3 patients had hematuria and one had dysuria. At the end of the study, all of the patients were stone free. Statistically, there were no differences in age, gender, stone size, location, and the number of sessions. Our results indicate that SWL without preoperative ureteral stenting is an effective and safe procedure that can be carried out in the pediatric population. Preoperative JJ stenting is unnecessary in patients, especially in those with smaller stone diameters. © 2016 S. Karger AG, Basel.

Potential of using stone matrix asphalt (SMA) for thin overlays

DOT National Transportation Integrated Search

2003-04-01

Stone matrix asphalt (SMA) has been used within the U.S. since 1991. To date almost all of the SMA mixes have had either a 12.5 or 19.0 mm nominal maximum aggregate size (NMAS). These two NMASs have been predominant because they conform to informatio...

Tract Sizes in Miniaturized Percutaneous Nephrolithotomy: A Systematic Review from the European Association of Urology Urolithiasis Guidelines Panel.

PubMed

Ruhayel, Yasir; Tepeler, Abdulkadir; Dabestani, Saeed; MacLennan, Steven; Petřík, Aleš; Sarica, Kemal; Seitz, Christian; Skolarikos, Andreas; Straub, Michael; Türk, Christian; Yuan, Yuhong; Knoll, Thomas

2017-08-01

Miniaturized instruments for percutaneous nephrolithotomy (PNL), utilizing tracts sized ≤22 Fr, have been developed in an effort to reduce the morbidity and increase the efficiency of stone removal compared with standard PNL (>22 Fr). We systematically reviewed all available evidence on the efficacy and safety of miniaturized PNL for removing renal calculi. The review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement. Since it was not possible to perform a meta-analysis, the data were summarized in a narrative synthesis. After screening 2945 abstracts, 18 studies were included (two randomized controlled trials [RCTs], six nonrandomized comparative studies, and 10 case series). Thirteen studies were full-text articles and five were only available as congress abstracts. The size of tracts used in miniaturized procedures ranged from 22 Fr to 4.8 Fr. The largest mean stone size treated using small instruments was 980mm 2 . Stone-free rates were comparable in miniaturized and standard PNL procedures. Procedures performed with small instruments tended to be associated with significantly lower blood loss, while the procedure duration tended to be significantly longer. Other complications were not notably different between PNL types. Study designs and populations were heterogeneous. Study limitations included selection and outcome reporting bias, as well as a lack of information on relevant confounding factors. The studies suggest that miniaturized PNL is at least as efficacious and safe as standard PNL for the removal of renal calculi. However, the quality of the evidence was poor, drawn mainly from small studies, the majority of which were single-arm case series, and only two of which were RCTs. Furthermore, the tract sizes used and types of stones treated were heterogeneous. Hence, the risks of bias and confounding were high, highlighting the need for more reliable data from RCTs. Removing kidney stones via percutaneous nephrolithotomy (PNL) using smaller sized instruments (mini-PNL) appears to be as effective and safe as using larger (traditional) instruments, but more clinical research is needed. Copyright © 2017 European Association of Urology. Published by Elsevier B.V. All rights reserved.

Kidney Stones in Primary Hyperoxaluria: New Lessons Learnt

PubMed Central

Jacob, Dorrit E.; Grohe, Bernd; Geßner, Michaela; Beck, Bodo B.; Hoppe, Bernd

2013-01-01

To investigate potential differences in stone composition with regard to the type of Primary Hyperoxaluria (PH), and in relation to the patient’s medical therapy (treatment naïve patients versus those on preventive medication) we examined twelve kidney stones from ten PH I and six stones from four PH III patients. Unfortunately, no PH II stones were available for analysis. The study on this set of stones indicates a more diverse composition of PH stones than previously reported and a potential dynamic response of morphology and composition of calculi to treatment with crystallization inhibitors (citrate, magnesium) in PH I. Stones formed by PH I patients under treatment are more compact and consist predominantly of calcium-oxalate monohydrate (COM, whewellite), while calcium-oxalate dihydrate (COD, weddellite) is only rarely present. In contrast, the single stone available from a treatment naïve PH I patient as well as stones from PH III patients prior to and under treatment with alkali citrate contained a wide size range of aggregated COD crystals. No significant effects of the treatment were noted in PH III stones. In disagreement with findings from previous studies, stones from patients with primary hyperoxaluria did not exclusively consist of COM. Progressive replacement of COD by small COM crystals could be caused by prolonged stone growth and residence times in the urinary tract, eventually resulting in complete replacement of calcium-oxalate dihydrate by the monohydrate form. The noted difference to the naïve PH I stone may reflect a reduced growth rate in response to treatment. This pilot study highlights the importance of detailed stone diagnostics and could be of therapeutic relevance in calcium-oxalates urolithiasis, provided that the effects of treatment can be reproduced in subsequent larger studies. PMID:23940605

Detecting Fragmentation of Kidney Stones in Lithotripsy by Means of Shock Wave Scattering

NASA Astrophysics Data System (ADS)

Sapozhnikov, Oleg A.; Trusov, Leonid A.; Owen, Neil R.; Bailey, Michael R.; Cleveland, Robin O.

2006-05-01

Although extracorporeal shock wave lithotripsy (a procedure of kidney stone comminution using focused shock waves) has been used clinically for many years, a proper monitoring of the stone fragmentation is still undeveloped. A method considered here is based on recording shock wave scattering signals with a focused receiver placed far from the stone, outside the patient body. When a fracture occurs in the stone or the stone becomes smaller, the elastic waves in the stone will propagate differently (e.g. shear waves will not cross a fracture) which, in turn, will change the scattered acoustic wave in the surrounding medium. Theoretical studies of the scattering phenomenon are based on a linear elastic model to predict shock wave scattering by a stone, with and without crack present in it. The elastic waves in the stone and the nearby liquid were modeled using a finite difference time domain approach. The subsequent acoustic propagation of the scattered waves into the far-field was calculated using the Helmholtz-Kirchhoff integral. Experimental studies were conducted using a research electrohydraulic lithotripter that produced the same acoustic output as an unmodified Dornier HM3 clinical lithotripter. Artificial stones, made from Ultracal-30 gypsum and acrylic, were used as targets. The stones had cylindrical shape and were positioned co-axially with the lithotripter axis. The scattered wave was measured by focused broadband PVDF hydrophone. It was shown that the size of the stone noticeably changed the signature of the reflected wave.

The effect of frequency doubled double pulse Nd:YAG laser fiber proximity to the target stone on transient cavitation and acoustic emission.

PubMed

Fuh, Eric; Haleblian, George E; Norris, Regina D; Albala, W David M; Simmons, Neal; Zhong, Pei; Preminger, Glenn M

2007-04-01

Scant information has been published describing the effect of laser fiber distance from the stone target on the mechanism of calculus fragmentation. Using high speed photography and acoustic emission measurements we characterized the impact of laser fiber proximity on stone comminution. We evaluated the effect of laser fiber distance from the stone target on resultant cavitation bubble formation and shock wave generation. Stone fragmentation was assessed using a FREDDY (frequency doubled double pulse Nd:YAG) (World of Medicine, Orlando, Florida) laser and a holmium laser. The FREDDY laser was operated using a 420 microm fiber at an output energy of 120 and 160 mJ in single and double pulse settings, and a pulse repetition rate of 1 Hz. The holmium laser was operated using a 200 microm fiber at an output energy of 1 to 3 J and a pulse repetition rate of 1 Hz. The surface of a 1 cm square BegoStone (Bego, Bremen, Germany) attached to an X-Y-Z translational stage was aligned perpendicular to the laser fiber, which was immersed in a Lucite tank filled with water at room temperature. An Imacon 200 high speed camera was used to capture transient cavitation bubbles at a framing rate of up to 1,000,000 frames per second. Acoustic emission signals associated with shock waves generated during the rapid expansion and collapse of the cavitation bubble were measured using a 1 MHz focused ultrasound transducer. At laser fiber distances of 3.0 mm or less cavitation bubbles and shock waves were observed with the FREDDY laser. In contrast to the holmium laser, the bubble size and shock wave intensity of the FREDDY laser was inversely related to the fiber-to-stone distance over the range tested (0.5 to 3.0 mm). While bubble size was noted to increase with a larger stone-to-fiber distance using the holmium laser, to consistently generate cavitation bubbles and shock waves using the FREDDY laser the laser fiber should be operated within 3.0 mm of the target stone. These findings have significant implications during clinical laser stone fragmentation.

Accuracy of Reduced-Dose Computed Tomography for Ureteral Stones in Emergency Department Patients

PubMed Central

Moore, Christopher L.; Daniels, Brock; Ghita, Monica; Gunabushanam, Gowthaman; Luty, Seth; Molinaro, Annette M.; Singh, Dinesh; Gross, Cary P.

2016-01-01

Study objective Reduced-dose computed tomography (CT) scans have been recommended for diagnosis of kidney stone but are rarely used in the emergency department (ED) setting. Test characteristics are incompletely characterized, particularly in obese patients. Our primary outcome is to determine the sensitivity and specificity of a reduced-dose CT protocol for symptomatic ureteral stones, particularly those large enough to require intervention, using a protocol stratified by patient size. Methods This was a prospective, blinded observational study of 201 patients at an academic medical center. Consenting subjects underwent both regular- and reduced-dose CT, stratified into a high and low body mass index (BMI) protocol based on effective abdominal diameter. Reduced-dose CT scans were interpreted by radiologists blinded to regular-dose interpretations. Follow-up for outcome and intervention was performed at 90 days. Results CT scans with both regular and reduced doses were conducted for 201 patients, with 63% receiving the high BMI reduced-dose protocol. Ureteral stone was identified in 102 patients (50.7%) of those receiving regular-dose CT, with a ureteral stone greater than 5 mm identified in 26 subjects (12.9%). Sensitivity of the reduced-dose CT for any ureteral stone was 90.2% (95% confidence interval [CI] 82.3% to 95.0%), with a specificity of 99.0% (95% CI 93.7% to 100.0%). For stones greater than 5 mm, sensitivity was 100% (95% CI 85.0% to 100.0%). Reduced-dose CT identified 96% of patients who required intervention for ureteral stone within 90 days. Mean reduction in size-specific dose estimate was 18.6 milligray (mGy), from 21.7 mGy (SD 9.7) to 3.4 mGy (SD 0.9). Conclusion CT with substantial dose reduction was 90.2% (95% CI 82.3% to 95.0%) sensitive and 98.9% (95% CI 85.0% to 100.0%) specific for ureteral stones in ED patients with a wide range of BMIs. Reduced-dose CT was 96.0% (95% CI 80.5% to 99.3%) sensitive for ureteral stones requiring intervention within 90 days. PMID:25441242

Temporal Trends and Treatment Outcomes of Flexible Ureteroscopy for Lower Pole Stones in a Tertiary Referral Stone Center.

PubMed

Orywal, Ann Kathrin; Knipper, Ann Sophie; Tiburtius, Christian; Gross, Andreas J; Netsch, Christopher

2015-12-01

To evaluate trends in efficacy and safety of flexible ureteroscopy (fURS) for the treatment of lower pole stones (LPS) over a 6-year period and to compare the annual outcomes after one fURS procedure retrospectively. Four hundred nine patients were treated for pure LPS. An analysis of the annual outcomes regarding patient characteristics, operative parameters, stone-free rates (SFRs), and complication rates (CRs) was performed. The SFR was stratified according to stone size and number of stones per patient. Patient data are expressed as mean±standard deviation. There were no annual differences regarding age, body-mass index, stone size (7.09±4.31 mm), number of stones per patient (1.66±2.86), operative time (52.93±33.58 minutes), use of postoperative stents (59.2%), and the Ho:YAG laser lithotripsy rate (49.4%) during the 6-year period. Total primary SFR (annual range) of 97.6% (88.2%-100%), 89.1% (82.9%-96.3%), 71% (60%-78.6%) for urinary calculi <5 mm (3.43±0.78 mm), 5-9 mm (6.69±1.34 mm), and ≥10 mm (13.09±6.02 mm) could be demonstrated over the 6-year period. The total SFR differed significantly between urinary calculi <5 mm, 5-9 mm, and those ≥10 mm (p<0.0179). The SFR (annual range) decreased from 90% (86.2%-95.4%) in patients with 1 stone to 84.1% (60%-100%) in those with ≥3 stones. Perioperative complications (annual range) occurred in 9.7% (6%-13.6%) of the patients (Clavien I 5.1% [1.2%-8.6%], Clavien II 2% [0%-4.9%], Clavien IIIa 0.9% [0%-3.4%], Clavien IIIb 1.7% [1.2%-4.8%]) without differences in the annual CR. fURS is a safe and efficacious procedure for the treatment of LPS with high primary SFR and low CR. fURS in larger LPS (≥10 mm) is associated with the risk for staged procedures.

Ureteral Stones: Implementation of a Reduced-Dose CT Protocol in Patients in the Emergency Department with Moderate to High Likelihood of Calculi on the Basis of STONE Score1

PubMed Central

Moore, Christopher L.; Daniels, Brock; Singh, Dinesh; Luty, Seth; Gunabushanam, Gowthaman; Ghita, Monica; Molinaro, Annette; Gross, Cary P.

2016-01-01

Purpose To determine if a reduced-dose computed tomography (CT) protocol could effectively help to identify patients in the emergency department (ED) with moderate to high likelihood of calculi who would require urologic intervention within 90 days. Materials and Methods The study was approved by the institutional review board and written informed consent with HIPAA authorization was obtained. This was a prospective, single-center study of patients in the ED with moderate to high likelihood of ureteral stone undergoing CT imaging. Objective likelihood of ureteral stone was determined by using the previously derived and validated STONE clinical prediction rule, which includes five elements: sex, timing, origin, nausea, and erythrocytes. All patients with high STONE score (STONE score, 10–13) underwent reduced-dose CT, while those with moderate likelihood of ureteral stone (moderate STONE score, 6–9) underwent reduced-dose CT or standard CT based on clinician discretion. Patients were followed to 90 days after initial imaging for clinical course and for the primary outcome of any intervention. Statistics are primarily descriptive and are reported as percentages, sensitivities, and specificities with 95% confidence intervals. Results There were 264 participants enrolled and 165 reduced-dose CTs performed; of these participants, 108 underwent reduced-dose CT alone with complete follow-up. Overall, 46 of 264 (17.4%) of patients underwent urologic intervention, and 25 of 108 (23.1%) patients who underwent reduced-dose CT underwent a urologic intervention; all were correctly diagnosed on the clinical report of the reduced-dose CT (sensitivity, 100%; 95% confidence interval: 86.7%, 100%). The average dose-length product for all standard-dose CTs was 857 mGy · cm ± 395 compared with 101 mGy · cm ± 39 for all reduced-dose CTs (average dose reduction, 88.2%). There were five interventions for nonurologic causes, three of which were urgent and none of which were missed when reduced-dose CT was performed. Conclusion A CT protocol with over 85% dose reduction can be used in patients with moderate to high likelihood of ureteral stone to safely and effectively identify patients in the ED who will require urologic intervention. PMID:26943230

In vitro assessment of fragmentation and repulsion of handheld lithotripsie devices

NASA Astrophysics Data System (ADS)

Sroka, Ronald; Pongratz, Thomas; Crameri, Giovanni; Haseke, Nicolas; Bader, Markus; Khoder, Wael

2013-03-01

Introduction: Different laser-systems are currently used for stone fragmentation in the upper urinary tract. The aim of our study was to evaluate probe velocity and displacement, retropulsion and fragmentation characteristics two novel devices the electromechanically driven EMS LithoBreaker® (EMS Medical), and of the CO2 cartridge driven LMA StoneBreaker® (Cook Urological) in vitro test models.Testing of the LithoBreaker® included additionally two different cushion guides (harder, softer) to assess the effect of the damper properties on the impulse characteristics. Patients and methods: Maximum probe velocities and displacements were measured using high-speed photography at a resolution of 100.000 frames per second. Repulsion testing was conducted through a 7.5 Fr ureteroscope in an underwater set-up. The probes were projected against a non-frangible led mass placed in a 15 Fr horizontally mounted silicone tube as an in-vitro model of the ureter. Repulsion was determined by measuring the distance the lead mass (0.98g) was displaced. Fragmentation efficiency was assessed by measuring the number of single shots required to break Bego Stone phantoms hard (15:3) and soft (15:6) with an average size of 7.5 mm x 5.5 mm placed on a metal mesh (edge length 3.15mm) into < 3 mm fragments. Mean and standard deviation were computed for all groups and statistical analysis was performed (student's t-test). Results: The StoneBreaker® yielded the highest velocity of 22.0 +/- 1.9 m/sec. followed by the LithoBreaker® assembled with the hard cushion guide of 14.2 +/- 0.5 m/sec and the soft probe guide of 11.5 +/-0.5 m/sec. accordingly. The maximum probe displacement for the StoneBreaker® was 1.04 mm and for the LithoBreaker® 0.9 mm and 1.1 mm (hard versus soft cushion guide). Repulsion produced using the 1mm probes showed no statistical differences between the devices. Using the 2mm probes, the hardness of the damper used significantly changed the repulsion behaviour of the LithoBreaker®. Using the 1mm probe, the amount of single shots for fragmentation of soft Bego Stones was significantly higher for the LithoBreaker® with soft cushion guide: mean 31.5 +/- 11.31 and hard cushion guide: mean 21.5 +/- 5.29 compared to the StoneBreaker®: mean 11.2 +/- 2.65. Fragmentation efficiency for the hard Bego Stones showed similar statistically significant results. Conclusion: The electromechanic LithoBreaker® and the pneumatic Stonebreaker® were shown to be effective in cracking stone phantoms with relatively low number of pulses. Fragmentation characteristics improved substantially with the higher hardness of the cushion support higher velocity equals higher fragmentation performance of the LithoBreaker®. Repulsion produced were at comparable levels. More testing is required to more detailed information on impulse frequency and capacity for stone clearance time to be used in clinical practice.

Follow-up imaging of the urinary tract in spinal injury patients: is a KUB necessary with every ultrasound?

PubMed

Tins, B; Teo, H-G; Popuri, R; Cassar-Pullicino, V; Tyrrell, P

2005-04-01

Prospective study of 100 consecutive patients. To evaluate the diagnostic usefulness of the urinary tract (KUB) radiograph routinely performed as part of spinal injury patient urinary tract screening with ultrasound (US) and the KUB radiograph. Orthopaedic and District General Hospital with spinal injuries unit, UK. Prospective study of the urinary tract of 100 consecutive routine follow-up spinal injury patients with KUB (kidneys, ureters, bladder) radiograph and US of the urinary tract. The percentage of the visualised area of kidneys and urinary bladder and relevant abnormal findings were recorded. Relevant patient history was recorded. In all, 80 men 20 women were examined (average age 46 years, average time since injury 11 years). A total of 199 kidneys and 99 urinary bladders were examined. On average, less than 50% of the renal area and about 70-75% of the urinary bladder area were visualised. Five patients had renal stones identified on the KUB radiograph, and of these two were seen on US. There were no stones seen on US only. The patient history was not helpful to identify patients with renal stones. Significant further renal abnormalities were identified with US in 14 patients, and with the KUB radiograph in 0 patients. Significant urinary bladder abnormalities were identified with US in 20 patients, and with the KUB radiograph in 0 patients. On average, less than 50% of the kidney area is visualised on the KUB due to overlying bowel markings making the KUB radiograph a poor tool to assess the kidneys. The KUB radiograph and US are poor tools to assess urinary tract stones. In the absence of a therapeutic consequence, the KUB radiograph does not seem justified in the routine follow-up of the urinary tract in spinal injury patients.

The Gachon University Ureteral Narrowing score: A comprehensive standardized system for predicting necessity of ureteral dilatation to treat proximal ureteral calculi.

PubMed

Lee, Seung Kyu; Kim, Tae Beom; Ko, Kwang-Pil; Kim, Chang Hee; Kim, Kwang Taek; Chung, Kyung Jin; Kim, Khae Hawn; Jung, Han; Yoon, Sang Jin; Oh, Jin Kyu

2016-07-01

For treating proximal ureteral calculi, treatment decision has been known still difficult to choose ureteroscopic lithotripsy (URS) or shockwave lithotripsy. The aims of our study are to identify the possible predictors for necessity of URS and to propose the Gachon University Ureteral Narrowing scoring system (GUUN score) as a helpful predictor. We evaluated 83 consecutive patients who underwent semirigid URS due to proximal ureteral calculi between April 2011 and February 2014 by a single surgeon. We reviewed patient characteristics and pre- and postoperative parameters and surgical records. We divided the patients into 2 groups (group 1, nondilation group; group 2, dilation group) according to whether or not balloon dilation was performed. A stepwise logistic regression was performed to identify the factors that predict dilatation. Receiver operating characteristic (ROC) curves were plotted and areas under the ROC curve (AUC) were calculated to GUUN score. Mean patients' age and their stone size were 48.53±12.90 years and 7.79±2.57 cm, respectively. Significantly smaller stone size (p=0.009), lower stone density (p=0.005), and lower ureteral density differences between ureteral narrowing level and far distal ureter (UD) (p<0.001) were observed in group 1 (n=34) than in group 2 (n=49). GUUN score consists of age, stone size and UD (AUC, 0.938). Overall stone-free clearance rate was 85.5%. We suggest that the GUUN score is an excellent scoring system to predict the necessity of ureteral dilatation for decision making whether or not to perform surgical manipulation.

OA03.04. To evaluate the effect of “Kadalikandadi kshara yoga” in the management of vataja ashmari”

PubMed Central

Waddar, B Sujata; Annigeri, Satish; Hemanthakumar, P

2013-01-01

Purpose: In current surgical practice we are facing problems in treating Ashmari disease effectively even with all modernized facilities, and are insufficient to reduce the prevalence of Ashmari and health care cost. Method: 20 diagnosed cases of Vataja Ashmari were selected for study and recorded through proforma designed for single group of observational study. And To evaluate the effect of “Kadalikandadi kshara yoga” in the management of Vataja Ashmari” Drug has administered through orally with water. Result: In this series of 20 patients of Ashmari, 20% patients were cured i.e. their stone was removed. 30% patients were markedly improved i.e. either their only stone was removed or it was broken into pieces or they showed 100% relief in their symptoms. 25% patients either showed reduction in the size of the stone or marked relief in their sign and symptoms. Remaining 25% patients showed no reduction in the size of the stone. Conclusion: The stones, which are passed, are maximum from ureter. Which shows significant level expelling action of the trailed drug. From the study it can be concluded that the action of the drug is encouraging in subjective part rather than objective, however duration of the treatment should be considered.

Quantitative evaluation of stone fragments in extracorporeal shock wave lithotripsy using a time reversal operator

NASA Astrophysics Data System (ADS)

Wang, Jen-Chieh; Zhou, Yufeng

2017-03-01

Extracorporeal shock wave lithotripsy (ESWL) has been used widely in the noninvasive treatment of kidney calculi. The fine fragments less than 2 mm in size can be discharged by urination, which determines the success of ESWL. Although ultrasonic and fluorescent imaging are used to localize the calculi, it's challenging to monitor the stone comminution progress, especially at the late stage of ESWL when fragments spread out as a cloud. The lack of real-time and quantitative evaluation makes this procedure semi-blind, resulting in either under- or over-treatment after the legal number of pulses required by FDA. The time reversal operator (TRO) method has the ability to detect point-like scatterers, and the number of non-zero eigenvalues of TRO is equal to that of the scatterers. In this study, the validation of TRO method to identify stones was illustrated from both numerical and experimental results for one to two stones with various sizes and locations. Furthermore, the parameters affecting the performance of TRO method has also been investigated. Overall, TRO method is effective in identifying the fragments in a stone cluster in real-time. Further development of a detection system and evaluation of its performance both in vitro and in vivo during ESWL is necessary for application.

A heuristic model of stone comminution in shock wave lithotripsy

PubMed Central

Smith, Nathan B.; Zhong, Pei

2013-01-01

A heuristic model is presented to describe the overall progression of stone comminution in shock wave lithotripsy (SWL), accounting for the effects of shock wave dose and the average peak pressure, P+(avg), incident on the stone during the treatment. The model is developed through adaptation of the Weibull theory for brittle fracture, incorporating threshold values in dose and P+(avg) that are required to initiate fragmentation. The model is validated against experimental data of stone comminution from two stone types (hard and soft BegoStone) obtained at various positions in lithotripter fields produced by two shock wave sources of different beam width and pulse profile both in water and in 1,3-butanediol (which suppresses cavitation). Subsequently, the model is used to assess the performance of a newly developed acoustic lens for electromagnetic lithotripters in comparison with its original counterpart both under static and simulated respiratory motion. The results have demonstrated the predictive value of this heuristic model in elucidating the physical basis for improved performance of the new lens. The model also provides a rationale for the selection of SWL treatment protocols to achieve effective stone comminution without elevating the risk of tissue injury. PMID:23927195

Percutaneous nephrolithotomy for the treatment of radiolucent renal stones in children: is it different opaque stone treatment?

PubMed

Adanur, Şenol; Ziypak, Tevfik; Sancaktutar, Ahmet Ali; Tepeler, Abdülkadir; Reşorlu, Berkan; Söylemez, Haluk; Dağgülli, Mansur; Özbey, İsa; Unsal, Ali

2014-02-01

We aimed to evaluate the effectiveness of percutaneous nephrolithotomy (PNL), stone-free rates, and related complications in children with radiolucent renal stones. A total of 56 patients aged <16 years from four institutions were enrolled in our study. Asymptomatic, clinically insignificant residual fragments measuring <4 mm or a complete stone-free status was accepted as the criterion for clinical success. Complications were evaluated according to the modified Clavien classification. The mean age of the patients was 7.8 ± 4.5 years. The mean stone size was calculated as 24.07 ± 10.4 mm. The median operative and fluoroscopy times were 53.2 min (15-170 min) and 172.4 s (5-520 s), respectively. The success rate after PNL monotherapy was 87.4%; the total success rate with shock wave lithotripsy used as an auxillary treatment method was detected as 94.6%. The total complication rate was 19.6% (11 patients). No adjacent organ injury was observed. All of the complications that occurred were minor according to the Clavien classification (Clavien Grades I-II). PNL can be applied to radiolucent pediatric renal stones in children with similar success, and complication rates as noted for radiopaque stones.

Acoustic Radiation Force of a Quasi-Gaussian Beam on an Elastic Sphere in a Fluid.

PubMed

Nikolaeva, A V; Sapozhnikov, O A; Bailey, M R

2016-09-01

Acoustic radiation force has many applications. One of the related technologies is the ability to noninvasively expel stones from the kidney. To optimize the procedure it is important to develop theoretical approaches that can provide rapid calculations of the radiation force depending in stone size and elastic properties, together with ultrasound beam diameter, intensity, and frequency. We hypothesize that the radiation force nonmonotonically depends on the ratio between the acoustic beam width and stone diameter because of coupling between the acoustic wave in the fluid and shear waves in the stone. Testing this hypothesis by considering a spherical stone and a quasi-Gaussian beam was performed in the current work. The calculation of the radiation force was conducted for elastic spheres of two types. Dependence of the magnitude of the radiation force on the beam diameter at various fixed values of stone diameters was modeled. In addition to using real material properties, speed of shear wave in the stone was varied to reveal the importance of shear waves in the stone. It was found that the radiation force reaches its maximum at the beamwidth comparable to the stone diameter; the gain in the force magnitude can reach 40% in comparison with the case of a narrow beam.

Uric acid versus non-uric acid urinary stones: differentiation with single energy CT texture analysis.

PubMed

Zhang, G-M-Y; Sun, H; Shi, B; Xu, M; Xue, H-D; Jin, Z-Y

2018-05-21

To evaluate the accuracy of computed tomography (CT) texture analysis (TA) to differentiate uric acid (UA) stones from non-UA stones on unenhanced CT in patients with urinary calculi with ex vivo Fourier transform infrared spectroscopy (FTIR) as the reference standard. Fourteen patients with 18 UA stones and 31 patients with 32 non-UA stones were included. All the patients had preoperative CT evaluation and subsequent surgical removal of the stones. CTTA was performed on CT images using commercially available research software. Each texture feature was evaluated using the non-parametric Mann-Whitney test. Receiver operating characteristic (ROC) curves were created and the area under the ROC curve (AUC) was calculated for texture parameters that were significantly different. The features were used to train support vector machine (SVM) classifiers. Diagnostic accuracy was evaluated. Compared to non-UA stones, UA stones had significantly lower mean, standard deviation and mean of positive pixels but higher kurtosis (p<0.001) on both unfiltered and filtered texture scales. There were no significant differences in entropy or skewness between UA and non-UA stones. The average SVM accuracy of texture features for differentiating UA from non-UA stones ranged from 88% to 92% (after 10-fold cross validation). A model incorporating standard deviation, skewness, and kurtosis from unfiltered texture scale images resulted in an AUC of 0.965±00.029 with a sensitivity of 94.4% and specificity of 93.7%. CTTA can be used to accurately differentiate UA stones from non-UA stones in vivo using unenhanced CT images. Copyright © 2018 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Combination of Electronic Choledochoscopy and Holmium Laser Lithotripsy for Complicated Biliary Calculus Treatment: A New Exploration.

PubMed

Ni, Zhong-Kai; Jin, Hai-Min; Li, Xiao-Wen; Li, Ye; Huang, Hai

2018-06-01

The safety and efficacy of the combination of electronic choledochoscopy and holmium laser lithotripsy for complicated bile duct stones were assessed. In total, 20 patients participated in this study, which was conducted between 2012 and 2017. None of the patients were candidates for endoscopic retrograde cholangiopancreatography with stone extraction. Outcome measures included complete stone clearance and complications postprocedure. Mean stone size was 17±5.2 mm (8 to 30 mm) and mean number of stones was 1.7±1.3 (1 to 5). The mean number of laser sessions was 1.3±0.7 (1 to 4). A mean of 1.0 to 1.5 J/20 to 25 Hz was applied during laser lithotripsy sessions with a mean operative time of 67.8±24.8 minutes. The clearance rate of stone was 18/20 (90%). No mortality existed in this study; however, 1 patient developed acute pancreatitis. The combination of holmium laser lithotripsy and electronic choledochoscopy for complicated biliary calculi is safe, reliable, and minimally invasive and has low residual stone rate.

B-mode Ultrasound Versus Color Doppler Twinkling Artifact in Detecting Kidney Stones

PubMed Central

Harper, Jonathan D.; Hsi, Ryan S.; Shah, Anup R.; Dighe, Manjiri K.; Carter, Stephen J.; Moshiri, Mariam; Paun, Marla; Lu, Wei; Bailey, Michael R.

2013-01-01

Abstract Purpose To compare color Doppler twinkling artifact and B-mode ultrasonography in detecting kidney stones. Patients and Methods Nine patients with recent CT scans prospectively underwent B-mode and twinkling artifact color Doppler ultrasonography on a commercial ultrasound machine. Video segments of the upper pole, interpolar area, and lower pole were created, randomized, and independently reviewed by three radiologists. Receiver operator characteristics were determined. Results There were 32 stones in 18 kidneys with a mean stone size of 8.9±7.5 mm. B-mode ultrasonography had 71% sensitivity, 48% specificity, 52% positive predictive value, and 68% negative predictive value, while twinkling artifact Doppler ultrasonography had 56% sensitivity, 74% specificity, 62% positive predictive value, and 68% negative predictive value. Conclusions When used alone, B-mode is more sensitive, but twinkling artifact is more specific in detecting kidney stones. This information may help users employ twinkling and B-mode to identify stones and developers to improve signal processing to harness the fundamental acoustic differences to ultimately improve stone detection. PMID:23067207

The rotary gallstone lithotrite to aid gallbladder extraction in laparoscopic cholecystectomy.

PubMed

Sackier, J M; Hunter, J G; Paz-Partlow, M; Cuschieri, A

1992-01-01

During laparoscopic cholecystectomy, a large stone burden may cause difficulty when extracting the gallbladder through the abdominal wall. Currently, the alternatives available to the surgeon include increasing the incision, removing stones singly, or utilizing complex fragmentation techniques like the pulsed dye laser. We have employed an electromechanical rotary gallstone lithotrite (RGL) to fragment stones to an aspiratable size. Initially, cholesterol spheres were pulverized in a latex balloon to demonstrate the efficacy of the device. Then, human gallstones were placed in the balloon and reduced to fragments less than or equal to 1 mm from initial sizes of 4-24 mm. Human stones were then inserted in ex vivo porcine gallbladders in a controlled experiment and treated with the device. Ten out of 12 tests were completed within 30 s; one test required 49 s and one 105 s to achieve complete fragmentation. Blinded histological evaluation demonstrated that tissue abrasion caused by use of the device would not interfere with the diagnosis of unsuspected malignancy. Clinical trials have now commenced under the auspices of the hospital ethical committee.

Comparison of treatment outcomes according to output voltage during shockwave lithotripsy for ureteral calculi: a prospective randomized multicenter study.

PubMed

Park, Jinsung; Kim, Hong-Wook; Hong, Sungwoo; Yang, Hee Jo; Chung, Hong

2015-05-01

To investigate the effect of fixed versus escalating voltage during SWL on treatment outcomes in patients with ureteral calculi (UC). A prospective, randomized, multicenter trial was conducted on 120 patients who were diagnosed with a single radiopaque UC. The patients were randomized into group C (n = 60, constant 13 kV, 3,000 shock wave, 2 Hz) or group E (n = 60, 11.4-12.0-13 kV per 1,000 shock waves, 2 Hz). They were evaluated by plain abdominal radiography and urinalysis at 1 week after a single session of SWL, and repeat SWL was performed if needed. The primary endpoint was stone-free rate at 1 week (SFR1) after SWL. Secondary endpoints were post-SWL visual pain score (VPS), oral analgesic requirements during 1 week, and cumulative SFRs after the second and third sessions of SWL. Groups C and E were well balanced in terms of baseline patients and stone characteristics, including pre-SWL VPS, stone location, and stone size (6.24 ± 1.92 vs. 6.30 ± 2.13 mm). SFR1s were not significantly different between groups C and E (60.0 vs. 68.3%, p = 0.447). Analyses stratified by stone size (<6 vs. ≥6 mm) showed no difference in SFR1 (p = 0.148 vs. 0.808). In the analyses stratified by stone location, group E tended to be more effective in distal UC (81.0 vs. 50.0%, p = 0.052), whereas no difference was seen in proximal UC (p = 0.487). Secondary endpoints were also similar between the two groups. Our results suggest that voltage escalation during SWL in UC may not provide superior stone fragmentation compared to fixed voltage.

Methanotrophs and Methanogens in Masonry

PubMed Central

Kussmaul, Martin; Wilimzig, Markus; Bock, Eberhard

1998-01-01

Methanotrophs were present in 48 of 225 stone samples which were removed from 19 historical buildings in Germany and Italy. The average cell number of methanotrophs was 20 CFU per g of stone, and their activities ranged between 11 and 42 pmol of CH4 g of stone−1 day−1. Twelve strains of methane-oxidizing bacteria were isolated. They belonged to the type II methanotrophs of the genera Methylocystis, Methylosinus, and Methylobacterium. In masonry, growth substrates like methane or methanol are available in very low concentrations. To determine if methane could be produced by the stone at rates sufficient to support growth of methanotrophs, methane production by stone samples under nonoxic conditions was examined. Methane production of 0.07 to 215 nmol of CH4 g of stone−1 day−1 was detected in 23 of 47 stone samples examined. This indicated the presence of the so-called “mini-methane”-producing bacteria and/or methanogenic archaea. Methanotrophs occurred in nearly all samples which showed methane production. This finding indicated that methanotrophs depend on biogenic methane production in or on stone surfaces of historical buildings. PMID:9797318

The role of trapped bubbles in kidney stone detection with the color Doppler ultrasound twinkling artifact.

PubMed

Simon, Julianna C; Sapozhnikov, Oleg A; Kreider, Wayne; Breshock, Michael; Williams, James C; Bailey, Michael R

2018-01-09

The color Doppler ultrasound twinkling artifact, which highlights kidney stones with rapidly changing color, has the potential to improve stone detection; however, its inconsistent appearance has limited its clinical utility. Recently, it was proposed stable crevice bubbles on the kidney stone surface cause twinkling; however, the hypothesis is not fully accepted because the bubbles have not been directly observed. In this paper, the micron or submicron-sized bubbles predicted by the crevice bubble hypothesis are enlarged in kidney stones of five primary compositions by exposure to acoustic rarefaction pulses or hypobaric static pressures in order to simultaneously capture their appearance by high-speed photography and ultrasound imaging. On filming stones that twinkle, consecutive rarefaction pulses from a lithotripter caused some bubbles to reproducibly grow from specific locations on the stone surface, suggesting the presence of pre-existing crevice bubbles. Hyperbaric and hypobaric static pressures were found to modify the twinkling artifact; however, the simple expectation that hyperbaric exposures reduce and hypobaric pressures increase twinkling by shrinking and enlarging bubbles, respectively, largely held for rough-surfaced stones but was inadequate for smoother stones. Twinkling was found to increase or decrease in response to elevated static pressure on smooth stones, perhaps because of the compression of internal voids. These results support the crevice bubble hypothesis of twinkling and suggest the kidney stone crevices that give rise to the twinkling phenomenon may be internal as well as external.

The role of trapped bubbles in kidney stone detection with the color Doppler ultrasound twinkling artifact

NASA Astrophysics Data System (ADS)

Simon, Julianna C.; Sapozhnikov, Oleg A.; Kreider, Wayne; Breshock, Michael; Williams, James C., Jr.; Bailey, Michael R.

2018-01-01

The color Doppler ultrasound twinkling artifact, which highlights kidney stones with rapidly changing color, has the potential to improve stone detection; however, its inconsistent appearance has limited its clinical utility. Recently, it was proposed stable crevice bubbles on the kidney stone surface cause twinkling; however, the hypothesis is not fully accepted because the bubbles have not been directly observed. In this paper, the micron or submicron-sized bubbles predicted by the crevice bubble hypothesis are enlarged in kidney stones of five primary compositions by exposure to acoustic rarefaction pulses or hypobaric static pressures in order to simultaneously capture their appearance by high-speed photography and ultrasound imaging. On filming stones that twinkle, consecutive rarefaction pulses from a lithotripter caused some bubbles to reproducibly grow from specific locations on the stone surface, suggesting the presence of pre-existing crevice bubbles. Hyperbaric and hypobaric static pressures were found to modify the twinkling artifact; however, the simple expectation that hyperbaric exposures reduce and hypobaric pressures increase twinkling by shrinking and enlarging bubbles, respectively, largely held for rough-surfaced stones but was inadequate for smoother stones. Twinkling was found to increase or decrease in response to elevated static pressure on smooth stones, perhaps because of the compression of internal voids. These results support the crevice bubble hypothesis of twinkling and suggest the kidney stone crevices that give rise to the twinkling phenomenon may be internal as well as external.

Retrograde intrarenal surgery for the treatment of renal stones in children: factors influencing stone clearance and complications.

PubMed

Azili, Mujdem Nur; Ozcan, Fatma; Tiryaki, Tugrul

2014-07-01

Retrograde intrarenal surgery (RIRS) is a known option for the treatment of upper tract calculi with an excellent success. However, the reports of RIRS in prepubertal children are limited. In this study, we evaluated the factors which affected the success rate and the complications of RIRS at renal stone treatment in childhood. We retrospectively reviewed the records of children under 14 years old who underwent RIRS for renal stone disease between January 2009 and December 2012. Patients' age, gender, body mass index (BMI), stone size, stone location, stone number, intraoperative complications, stone free status, postoperative complications were recorded. There were 80 ureterorenoscopic procedures performed in 58 renal units of 47 children (23 males and 24 females). The patients' ages ranged from 8 months to 14 years (mean age 4.7 ± 3.4 years). There was a difference in the distribution of symptoms in age groups. UTI was higher in the 1-4 years age group, abdominal pain was seen mostly in children aged 5-14 years. Multiple stones (included staghorn stone) were noted in 60.4% of patients. In 27.6% of patients, ureteral stones were accompanied by renal stones in our series. In the infancy group, cystine and staghorn stones were more frequently seen, mostly bilateral. After a single ureteroscopic procedure for intrarenal stones in children, we achieved stone free status in 50.9% of the ureters (n=26). After the repeated sessions, the stone clearance rate reached to 85.1%. Retrograde intrarenal surgery can be used as a first line therapy to treat renal stones in children. This is especially important if an associated ureteral stone is present that requires treatment; or in patients with cystinuria, which is not favorably treated with ESWL. Complications were seen more frequently in patients with cystine stones. Extravasation was noted more frequently in patients admitted with UTIs. There was a significant relationship between the conversion to open procedures and the age groups, with most procedures occurring in infancy. The parents should be informed about the probability of multiple procedures to achieve stone free status. Copyright © 2014 Elsevier Inc. All rights reserved.

Holmium:YAG (lambda = 2,120 nm) versus thulium fiber (lambda = 1,908 nm) laser lithotripsy.

PubMed

Blackmon, Richard L; Irby, Pierce B; Fried, Nathaniel M

2010-03-01

The holmium:YAG laser is currently the most common laser lithotripter. However, recent experimental studies have demonstrated that the thulium fiber laser is also capable of vaporizing urinary stones. The high-temperature water absorption coefficient for the thulium wavelength (mu(a) = 160 cm(-1) at lambda = 1,908 nm) is significantly higher than for the holmium wavelength (mu(a) = 28 cm(-1) at lambda = 2,120 nm). We hypothesize that this should translate into more efficient laser lithotripsy using the thulium fiber laser. This study directly compares stone vaporization rates for holmium and thulium fiber lasers. Holmium laser radiation pulsed at 3 Hz with 70 mJ pulse energy and 220 microseconds pulse duration was delivered through a 100-microm-core silica fiber to human uric acid (UA) and calcium oxalate monohydrate (COM) stones, ex vivo (n = 10 each). Thulium fiber laser radiation pulsed at 10 Hz with 70 mJ pulse energy and 1-millisecond pulse duration was also delivered through a 100-microm fiber for the same sets of 10 stones each. For the same number of pulses and total energy (126 J) delivered to each stone, the mass loss averaged 2.4+/-0.6 mg (UA) and 0.7+/-0.2 mg (COM) for the holmium laser and 12.6+/-2.5 mg (UA) and 6.8+/-1.7 (COM) for the thulium fiber laser. UA and COM stone vaporization rates for the thulium fiber laser averaged 5-10 times higher than for the holmium laser at 70 mJ pulse energies. With further development, the thulium fiber laser may represent an alternative to the conventional holmium laser for more efficient laser lithotripsy.

Comparison of renal pelvic pressure and postoperative fever incidence between standard- and mini-tract percutaneous nephrolithotomy.

PubMed

Wu, Cheng; Hua, Li-Xin; Zhang, Jian-Zhong; Zhou, Xun-Rong; Zhong, Wei; Ni, Hao-Dong

2017-01-01

This study was proposed to compare the clinical effectiveness of mini-tract percutaneous nephrolithotomy (MPCNL) with standard-tract percutaneous nephrolithotomy (SPCNL) and verify whether MPCNL is associated with both higher renal pelvic pressure (RPP) and incidence of postoperative fever. A total of 228 patients with kidney stone were randomly allocated to the MPCNL group (n=114) and SPCNL group (n=114). Both intraoperative and postoperative indexes along with the incidence of complications were compared between the two treatment groups. RPP was measured using a baroreceptor which was connected to an open-ended ureteric catheter during the operation of percutaneous nephrolithotomy. The MPCNL group exhibited significantly longer average operation time, more average amount of flush water, and lesser average amount of bleeding during the operation than the SPCNL group (p<0.05). Moreover, significantly lesser average amount of postoperative serum creatinine, shorter average hospital stay, and more average amount of postoperative hemoglobin were observed in the MPCNL group than in the SPCNL group (p<0.05). MPCNL were more applicable to clear caliceal stones (p<0.05), whereas SPCNL were more effective for the removal of simple pelvic stones. The difference in the incidence of postoperative fever between the two treatment groups also appeared to be significant (p<0.05). Logistic regression provided solid evidence that both RPP and its accumulation time at which RPP≥30 mmHg significantly affected the incidence of postoperative fever. MPCNL was correlated with both higher RPP and increased likelihood of postoperative fever compared with SPCNL. Copyright © 2016 The Authors. Published by Elsevier Taiwan.. All rights reserved.

Stone formation and calcification by nanobacteria in the human body

NASA Astrophysics Data System (ADS)

Ciftcioglu, Neva; Bjorklund, Michael; Kajander, E. Olavi

1998-07-01

The formation of discrete and organized inorganic crystalline structures within macromolecular extracellular matrices is a widespread biological phenomenon generally referred to as biomineralization. Recently, bacteria have been implicated as factors in biogeochemical cycles for formation of many minerals in aqueous sediments. We have found nanobacterial culture systems that allow for reproducible production of apatite calcification in vitro. Depending on the culture conditions, tiny nanocolloid-sized particles covered with apatite, forming various size of aggregates and stones were observed. In this study, we detected the presence of nanobacteria in demineralized trilobit fossil, geode, apatite, and calcite stones by immunofluorescence staining. Amethyst and other quartz stones, and chalk gave negative results. Microorganisms are capable of depositing apatite outside the thermodynamic equilibrium in sea water. We bring now evidence that this occurs in the human body as well. Previously, only struvite kidney stones composed of magnesium ammonium phosphate and small amounts of apatite have been regarded as bacteria related. 90 percent of demineralized human kidney stones now screened, contained nanobacteria. At least three different distribution patterns of nanobacteria were conditions, and human kidney stones that are formed from small apatite units. Prerequisites for the formation of kidney stones are the supersaturation of urine and presence of nidi for crystallization. Nanobacteria are important nidi and their presence might be of special interest in space flights where supersaturation of urine is present due to the loss of bone. Furthermore, we bring evidence that nanobacteria may act as crystallization nidi for the formation of biogenic apatite structures in tissue calcification found in e.g., atherosclerotic plaques, extensive metastatic and tumoral calcification, acute periarthritis, malacoplakia, and malignant diseases. In nanaobacteria-infected fibroblasts, electron microscopy revealed intra- and extra-cellular needle-like crystal deposits, which were stainable with von Kossa stain and resemble calcospherules found in pathological calcification. Thus bacteria-mediated apatite formation takes place in aqueous environments, in humans and in geological sediments.

Gallstone dissolution using mono-octanoin infusion through an endoscopically placed nasobiliary catheter.

PubMed

Venu, R P; Geenen, J E; Toouli, J; Hogan, W J; Kozlov, N; Stewart, E T

1982-04-01

Endoscopic sphincterotomy is widely being used for the treatment of common bile duct stones. In a small group of patients the gallstones are large in size and, hence, difficult to be extracted after a successful endoscopic sphincterotomy. We used a constant infusion of mono-octanoin through a nasobiliary catheter in nine such patients. This method was successful in partial or complete dissolution of the stones in 74% of the patients. In the remaining 36% of the patients, the stones were noted to be soft allowing easy extraction by crushing.

Distribution of ureteral stones and factors affecting their location and expulsion in patients with renal colic.

PubMed

Moon, Young Joon; Kim, Hong-Wook; Kim, Jin Bum; Kim, Hyung Joon; Chang, Young-Seop

2015-10-01

To evaluate the distribution of ureteral stones and to determine their characteristics and expulsion rate based on their location. We retrospectively reviewed computed tomography (CT) findings of 246 patients who visited our Emergency Department (ED) for renal colic caused by unilateral ureteral stones between January 2013 and April 2014. Histograms were constructed to plot the distribution of stones based on initial CT findings. Data from 144 of the 246 patients who underwent medical expulsive therapy (MET) for 2 weeks were analyzed to evaluate the factors responsible for the stone distribution and expulsion. The upper ureter and ureterovesical junction (UVJ) were 2 peak locations at which stones initially lodged. Stones lodged at the upper ureter and ureteropelvic junction (group A) had a larger longitudinal diameter (4.21 mm vs. 3.56 mm, p=0.004) compared to those lodged at the lower ureter and UVJ (group B). The expulsion rate was 75.6% and 94.9% in groups A and B, respectively. There was no significant difference in the time interval from initiation of renal colic to arrival at the ED between groups A and B (p=0.422). Stone diameter was a significant predictor of MET failure (odds ratio [OR], 1.795; p=0.005) but the initial stone location was not (OR, 0.299; p=0.082). The upper ureter and UVJ are 2 peak sites at which stones lodge. For stone size 10 mm or less, initial stone lodge site is not a significant predictor of MET failure in patients who have no previous history of active stone treatment in the ureter.

Pediatric ureteroscopic stone management.

PubMed

Thomas, John C; DeMarco, Romano T; Donohoe, Jeffrey M; Adams, Mark C; Brock, John W; Pope, John C

2005-09-01

We reviewed our experience of 5 years using ureteroscopy with laser lithotripsy to treat stone disease in prepubertal children. A retrospective review was performed of all ureteroscopic procedures performed in prepubertal children. A total of 33 ureteroscopic procedures were performed in 29 prepubertal children (15 males and 14 females) 5 to 144 months old (mean age 94 months, including 3 patients 24 months or younger). Stones were located in the renal pelvis in 1 case (3%), proximal ureter in 3 (9%), mid ureter in 5 (15%) and distal ureter in 24 (73%). Stone size ranged from 3 to 14 mm (mean 6). Eight patients required balloon dilation of the ureteral orifice. Followup ranged from 1 to 66 months (mean 11). Stone-free rate after initial ureteroscopy and laser lithotripsy was 88%, with all distal and mid ureteral stones (3 to 9 mm, mean 5) successfully treated. Three patients with proximal ureteral stones 7 to 14 mm in diameter (mean 10.3) required a secondary procedure (repeat ureteroscopy in 2 and shock wave lithotripsy in 1) to become stone-free. One patient with cystinuria and a renal pelvic stone measuring 14 mm required shock wave lithotripsy and percutaneous nephrostolithotomy. There were no major complications of ureteroscopy but there was 1 case of extravasation at the ureterovesical junction after balloon dilation that was managed with stent placement. Although more patients and longer followup are needed, ureteroscopy with laser lithotripsy is an excellent first line treatment for children with stones in whom conservative therapy fails, especially those with distal and mid ureteral stones. Patients with a stone burden of 10 mm or greater, especially in the proximal ureter, likely will require a secondary procedure to become stone-free.

Comparison of Retrograde Intrarenal Surgery and Micro-Percutaneous Nephrolithotomy in Moderately Sized Pediatric Kidney Stones.

PubMed

Baş, Okan; Dede, Onur; Aydogmus, Yasin; Utangaç, Mazhar; Yikilmaz, Taha Numan; Damar, Erman; Nalbant, İsmail; Bozkurt, Ömer Faruk

2016-07-01

To compare the effectiveness and reliability of retrograde intrarenal surgery (RIRS) and micro-percutaneous nephrolithotomy (micro-perc) for the management of kidney stones in pediatric patients. A retrospective analysis was made of pediatric patients aged <18 years with kidney stones that ranged from 10 to 20 mm in size, who underwent RIRS (n = 36) or micro-perc (n = 45) in referral centers. In the RIRS group, the mean age of patients was 8.39 ± 4.72 years and in the micro-perc group, it was 5.62 ± 4.50 years (p = 0.01). The mean stone size was 12.80 ± 3.03 mm in the RIRS group and 13.97 ± 3.46 mm in the micro-perc group (p = 0.189). The success rate was 86.2% (n = 31) in the RIRS group and 80.0% (n = 36) in the micro-perc group (p = 0.47). The mean complication rate was 16.6% and 13.3% in the RIRS and micro-perc groups, respectively (p = 0.675). Hospital stay and radiation exposure were significantly lower in the RIRS group (all p < 0.001). The mean anesthesia session was 1.94 in the RIRS group and 1.26 in the micro-perc group (p < 0.001). The mean hemoglobin drop was 0.53 ± 0.87 g/dL in the micro-perc group, and none of the cases required blood transfusion. The results of this study suggested that micro-perc and RIRS were highly effective methods for the treatment of moderately sized renal stones in children, with comparable success and complication rates. Patients and their parents should be informed about the currently available treatment options, and of their efficacy and safety. However, further clinical trials are needed to support these results.

Traces of the heritage arising from the Macelj sandstone

NASA Astrophysics Data System (ADS)

Golež, Mateja

2014-05-01

The landscape of Southeast Slovenia and its stone heritage principally reveal itself through various Miocene sandstones. The most frequently found type on the borderline between Slovenia and Croatia, i.e. east of Rogatec, is the micaceous-quartz Macelj sandstone. This rock ranges in colour from greenish grey to bluish grey and yellowish, depending on the content of glauconite, which colours it green. In its composition, the rock is a heterogeneous mixture of grains of quartz, dolomite, muscovite, microcline, anorthite and glauconite. The average size of grains is 300μm. In cross-section, they are oblong, semi-rounded or round. The mechanical-physical and durability properties of the Macelj sandstone, which have been characterised pursuant to the applicable standards for natural stone, reveal that the rock exhibits poor resistance to active substances from the atmosphere, particularly in the presence of salt. In the surroundings of Rogatec, there are around 45 abandoned quarries of the Macelj sandstone, which are the result of the exploitation of this mineral resource from the 17th century on. The local quarrymen earned their bread until 1957, when the Kambrus quarry industry closed down. From the original use of this mineral resource as construction and decorative material, the useful value of the Macelj sandstone expanded during the development of the metals industry to the manufacture of large and small grindstones for the needs of the domestic and international market. Therefore, traces of quarrying can not only be seen in the disused quarries, but also in the rich architectural heritage of Rogatec and its surroundings, the stone furniture - from portals, window frames, wells, various troughs, pavements to stone walls - and other. The living quarrying heritage slowly passed into oblivion after World War II, although the analysis of the social image of the people residing in Rogatec and its surroundings revealed that there was an average of one stonemason in every house in the period between both World Wars. Only few masters succeeded in transferring their know-how to their descendants, which is why the local community has been making efforts to include the quarrying and working of the Macelj sandstone in educational workshops that are being carried out at the Open-Air Museum in Rogatec.

Proficiency of virtual reality simulator training in flexible retrograde ureteroscopy renal stone management.

PubMed

Cai, Jian-liang; Zhang, Yi; Sun, Guo-feng; Li, Ning-chen; Yuan, Xue-li; Na, Yan-qun

2013-10-01

Minimally invasive flexible ureteroscopy techniques have widely adopted in the management of patients with renal stones. We performed this study to investigate the value of virtual reality simulator training in retrograde flexible ureteroscopy renal stone treatment for catechumen. Thirty catechumen, included 17 attending physicians and 13 associate chief physicians, were selected for study. The trainees first underwent 1-hour basic training to get familiar with the instrument and basic procedures, then followed by 4-hour practice on virtual reality simulators. Before and after the 4-hour training, all trainees undertake an assessment with task 7 program (right low pole calyces stone management). We documented for each trainee the total time of procedure, time of progressing from the orifice to stone, stone translocation and fragmentation time, laser operate proficiency scale, total laser energy, maximal size of residual stone fragments, number of trauma from the scopes and tools, damage to the scope and global rating scale (GRS). The proficiency of this training program was analyzed by the comparison of the first and second assessment outcomes. Significant improvement was observed in retrograde flexible ureteroscopy management of renal stone on virtual reality simulators after finishing the 4 hour special-purpose training. This was demonstrated by improvement in total procedure time ((18.37±2.59) minutes vs. (38.67±1.94) minutes), progressing time from the orifice to stone ((4.00±1.08) minutes vs. (13.80±2.01) minutes), time of stone translocation ((1.80±0.71) minutes vs. (6.57±1.01) minutes), fragmentation time ((4.43±1.25) minutes vs. (13.53±1.46) minutes), laser operate proficiency scale (8.47±0.73 vs. 3.77±0.77), total laser energy ((3231.6±401.4) W vs. (5329.8±448.9) W), maximal size of residual stone fragments ((2.66±0.39) mm vs. (5.77±0.63) mm), number of trauma from the scopes and tools (3.27±1.01 vs. 10.37±3.02), damage to the scope (0 vs. 0.97±0.76) and GRS (29.27±2.95 vs. 9.87±2.21). The differences between the first and the second assessment were all statistically significant (all P < 0.01). The virtual reality simulator training program can help the trainees to rapidly improve their retrograde flexible ureteroscopy skill in renal stone treatment.

Laser lithotripsy of gallstones: alexandrite and rhodamine-6G versus coumarin dye laser: fragmentation and fiber burn-off in vitro

NASA Astrophysics Data System (ADS)

Hochberger, Juergen; Bredt, Marion; Mueller, Gudrun; Hahn, Eckhart G.; Ell, Christian

1993-05-01

In the following study three different pulsed laser lithotripsy systems were compared for the fine fragmentation of identical sets of natural and synthetic gallstones `in vitro.' Using a pulsed coumarin dye laser (504 nm), a pulsed rhodamine 6G dye laser (595 nm), and a pulsed Alexandrite laser (755 nm) a total of 184 concrements of known chemical composition, size, and weight were disintegrated to a fragment size of

Flexible Ureteroscopic Management of Horseshoe Kidney Renal Calculi.

PubMed

Ding, Jie; Huang, Yunteng; Gu, Siping; Chen, Yifan; Peng, Jie; Bai, Qiang; Ye, Min; Qi, Jun

2015-01-01

To evaluate the clinical efficacy of flexible ureteroscope (F-URS) combined with holmium laser lithotripter in treating renal calculi in horseshoe kidney. From November 2010 to December 2013, the medical history and charts of sixteen patients (mean age 42.9 ± 11.6 years, range 26-66 years), including 13 males and 3 females were analyzed retrospectively. Mean stone burden was 29 ± 8 mm (range 17-42 mm2). Mean stone digitized surface area (DSA) was 321 ± 94 mm2 (range 180-538 mm2). Under spinal anesthesia in a modified lithotomy position with the head down, rigid ureteroscope was placed firstly into the ureter to reach the level of the pelvis, a zebra guide wire was inserted and following the removal of the rigid ureteroscope, an ureteral access sheath was positioned along the guide wire, then passed the URF P-5 flexible ureteroscope into the renal cavities over the guidewire. After locating the stones, holmium laser lithotripsy was performed. The average operative time was 92 ± 16 minutes (range 74-127 min.). No major complications were encountered. Ten patients obtained stone-free status with one session, four obtained stone-free status after two sessions. Single session stone-free rate was 62.5%, overall stone-free rate was 87.5%. Two patients have small residual stones in the lower pole. F-URS combined with holmium laser lithotripter and nitinol basket, is safe and effective in dealing with moderate stone diameter (<30 mm) in HSKs with high clearance rates and low complication rates.

Minimally invasive percutaneous cystostomy with ureteroscopic pneumatic lithotripsy for calculus in bladder diverticula

PubMed Central

GU, SI-PING; YOU, ZHI-YUAN; HUANG, YUNTENG; LU, YI-JIN; HE, CAOHUI; CAI, XIAO-DONG; ZHOU, XIAO-MING

2013-01-01

The aim of this study was to investigate the effectiveness of minimally invasive percutaneous cystostomy with ureteroscopic pneumatic lithotripsy for treating calculus in bladder diverticula. Percutaneous cystostomy with ureteroscopic pneumatic lithotripsy was performed on six elderly male patients with calculi in bladder diverticula, who could not be treated with transurethral ureteroscopic lithotripsy. The stones were successfully removed from all patients, with no complications such as bladder perforation, rupture, urethritis or cystitis. The surgery time was 15–60 min, with an average time of 32 min. Postoperative ultrasound or X-ray examination showed no stone residues and the bladder stoma healed well. No recurrent stones were detected in the follow-up of 3–24 months (average, 16 months). Minimally invasive percutaneous cystostomy with ureteroscopic pneumatic lithotripsy is a safe, efficient and easy treatment for calculus in bladder diverticula. This method provides a new clinical approach for lithotripsy and we suggest that it is worthy of wider use. PMID:23837044

Changing patterns of gallstone disease in Korea.

PubMed

Park, Yong-Hyun; Park, Sang-Jae; Jang, Jin-Young; Ahn, Young Joon; Park, Youn-Chan; Yoon, Yong Bum; Kim, Sun-Whe

2004-02-01

The aim of this study was to investigate the epidemiologic characteristics and changing patterns of gallstone disease in Korea over a recent 20-year period. A total of 4020 gallstone patients who had undergone surgery at Seoul National University Hospital during 1981-2000 were analyzed according to periods: period I (1981-1985: 831 cases); period II (1986-1990: 888 cases); period III (1991-1995: 1040 cases); period IV (1996-2000: 1261 cases). The literature from 13 institutes in Korea reporting a total of 13,101 gallstone cases were reviewed to elucidate the nationwide trend. The number of gallstone cases gradually increased. A female predominance was not noted (F/M = 1.17-1.37) as is seen in Western countries. The patients with common bile duct (CBD) stones were older than those with gallbladder (GB) stones or intrahepatic duct (IHD) stones. Over time, the relative proportion of those with a GB stone increased, plateauing (80-85%) during the 1990s; that of patients with CBD stones decreased (34% --> 19%); and that of those with IHD stones remained unchanged (11-15%). Over the entire period, the rural pattern of gallstone formation (low number of GB stones, high numbers of CBD and IHD stones) has become similar to the urban pattern. The body mass index (BMI) of the GB stone group was above average, as were the BMIs of the CBD stone and IHD stone groups. Throughout the literature review, this same changing pattern of the relative proportion of gallstone disease was confirmed. Thus the pattern of gallstone disease in Korea has become similar to that seen in Western countries except for a high prevalence of hepatolithiasis.

Human stones.

PubMed

Lonsdale, K

1968-03-15

X-ray diffraction studies have shown that there are several different kinds of human urinary calculi, with different age, sex, period, and geographical distributions. Juvenile bladder stones are typically urate and oxalate in small boys in certain stone belts. They have disappeared in some areas, particularly in Britain, but are still common in Thailand. India. and Turkey. Their cause is unknown. Adult bladder stones, formerly common in elderly men, were largely of uric acid and were due to a faulty diet. Juvenile kidney stones are rare, except in Turkey where they are similar to juvenile bladder stones. Adult kidney stones are by far the most universally common, especially in technically developed communities. They are found in both sexes (equally at postmortem), and in the United States and in Czechoslovakia the average number of hospital entries for stones, relative to the whole population, is about 1 per 1000 per annum (increasing) although the incidence in different districts varies by 4 to 1 or more. Such stones are mainly calcium oxalates and calcium and MgNH(4) phosphates. The incidence among the administrative class is at least 20 times that among agricultural workers, relative to their numbers. Stones are reported also to be an occupational hazard for air pilots. It is probably that much more exercise and the drinking of more water to prevent kidney dehydration (spirits and coffee are not effective for this purpose) would lower the high rate of incidence. Moderate acidification would prevent phosphate supersaturation of the urine, but is not effective for oxalates. It seems certain that, once a suitable seed is formed, epitaxy is largely responsible for deposition from urines that would otherwise remain supersaturated until voided. This would explain the curioLls radial and layered texture of many stones. Laboratory experiments might suggest ways of preventing orientated overgrowth.

Photocatalytic self-cleaning TiO2 coatings on carbonatic stones

NASA Astrophysics Data System (ADS)

Bergamonti, Laura; Bondioli, Federica; Alfieri, Ilaria; Lorenzi, Andrea; Mattarozzi, Monica; Predieri, Giovanni; Lottici, Pier Paolo

2016-02-01

A self-cleaning coating based on TiO2 nanoparticles obtained by sol-gel method in an alkaline environment has been tested on different types of carbonatic stones: Botticino, Carrara and Pietra Dorata, frequently used in historic buildings. XRD and Raman measurements confirmed the nanocrystalline nature of titania in anatase form, with 5-10 nm crystal size, and evidenced a small amount of brookite. A fast photocatalytic oxidation by TiO2 coatings of the stained stones with methyl orange and methylene blue under UV lamp irradiation has been assessed. The enhancement of surface wettability due to UV-induced TiO2 hydrophilicity has been evidenced by contact angle measurements. ESEM/EDS showed a surface distribution of the coating fairly homogeneous. The coating does not introduce significant colorimetric changes of the stones and does not alter the water capillarity absorption. Thus, the alkaline nanocrystalline TiO2 is promising for self-cleaning coatings on carbonatic stones.

Single-center experience using three shockwave lithotripters with different generator designs in management of urinary calculi.

PubMed

Ng, C F; Thompson, T J; McLornan, L; Tolley, D A

2006-01-01

We retrospectively reviewed the treatment outcomes of extracorporeal shockwave lithotripsy (SWL) in a single center using either the Wolf Piezolith 2300 (a piezoelectric lithotripter), the Dornier MPL9000 (an electrohydraulic lithotripter), or the Dornier Compact Delta (an electromagnetic lithotripter) from January 1992 to June 2002. A series of 3123 (1449 Piezolith 2300, 780 MPL9000, and 894 Compact Delta) solitary radiopaque urinary stones of < or =15 mm receiving primary SWL were identified. "Stone free" was defined as the absence of evidence of stone on plain radiography. Treatment outcomes were assessed by the stone-free rate 3 months after one treatment session, the retreatment rate, the auxiliary procedure rate, the complication rate, and the effectiveness quotient (EQ). In order to have a better assessment of the efficacy of individual lithotripters, multiple logistic regression was performed to control various factors affecting treatment outcomes, including lithotripter-type, patients' sex and age, history of previous SWL, the stone characteristics (side, site, and size), and the presence of a stent or nephrostomy tube. There were significant differences in the stone site distribution and mean stone size among the three groups. The overall EQ for the Piezolith 2300, MPL9000, and Compact Delta were 0.345, 0.303, and 0.257, respectively. However, using the multiple logistic regression model, the adjusted odds ratio (AOR) of a patient being stone-free after 3 month for the Piezolith 2300 and MPL9000 (using the Compact Delta as the referent category) were 1.38 (95% CI 1.15, 1.65) and 1.72 (95% CI 1.39, 2.11), respectively. Patients treated using the MPL9000 had significantly less re-treatment (AOR = 0.57; 95% CI 0.48, 0.69) than the other groups. No significant difference in the auxiliary procedure rate and complication rate for the three machines was observed. Based on multivariate analysis results, the Dornier MPL9000 had the best treatment outcomes in terms of stone-free rate and re-treatment rate among the three lithotripters.

Factors predictive of adverse events following endoscopic papillary large balloon dilation: results from a multicenter series.

PubMed

Park, Soo Jung; Kim, Jin Hong; Hwang, Jae Chul; Kim, Ho Gak; Lee, Don Haeng; Jeong, Seok; Cha, Sang-Woo; Cho, Young Deok; Kim, Hong Ja; Kim, Jong Hyeok; Moon, Jong Ho; Park, Sang-Heum; Itoi, Takao; Isayama, Hiroyuki; Kogure, Hirofumi; Lee, Se Joon; Jung, Kyo Tae; Lee, Hye Sun; Baron, Todd H; Lee, Dong Ki

2013-04-01

Lack of established guidelines for endoscopic papillary large balloon dilation (EPLBD) may be a reason for aversion of its use in removal of large common bile duct (CBD) stones. We sought to identify factors predictive of adverse events (AEs) following EPLBD. This multicenter retrospective study investigated 946 consecutive patients who underwent attempted removal of CBD stones ≥10 mm in size using EPLBD (balloon size 12-20 mm) with or without endoscopic sphincterotomy (EST) at 12 academic medical centers in Korea and Japan. Ninety-five (10.0 %) patients exhibited AEs including bleeding in 56, pancreatitis in 24, perforation in nine, and cholangitis in six; 90 (94.7 %) of these were classified as mild or moderate in severity. There were four deaths, three as a result of perforation and one due to delayed massive bleeding. Causative factors identified in fatal cases were full-EST and continued balloon inflation despite a persistent waist seen fluoroscopically. Multivariate analyses showed that cirrhosis (OR 8.03, p = 0.003), length of EST (full-EST: OR 6.22, p < 0.001) and stone size (≥16 mm: OR 4.00, p < 0.001) were associated with increased bleeding, and distal CBD stricture (OR 17.08, p < 0.001) was an independent predictor for perforation. On the other hand, balloon size was associated with deceased pancreatitis (≥14 mm: OR 0.27, p = 0.015). EPLBD appears to be a safe and effective therapeutic approach for retrieval of large stones in patients without distal CBD strictures and when performed without full-EST.

Computerized tomography magnified bone windows are superior to standard soft tissue windows for accurate measurement of stone size: an in vitro and clinical study.

PubMed

Eisner, Brian H; Kambadakone, Avinash; Monga, Manoj; Anderson, James K; Thoreson, Andrew A; Lee, Hang; Dretler, Stephen P; Sahani, Dushyant V

2009-04-01

We determined the most accurate method of measuring urinary stones on computerized tomography. For the in vitro portion of the study 24 calculi, including 12 calcium oxalate monohydrate and 12 uric acid stones, that had been previously collected at our clinic were measured manually with hand calipers as the gold standard measurement. The calculi were then embedded into human kidney-sized potatoes and scanned using 64-slice multidetector computerized tomography. Computerized tomography measurements were performed at 4 window settings, including standard soft tissue windows (window width-320 and window length-50), standard bone windows (window width-1120 and window length-300), 5.13x magnified soft tissue windows and 5.13x magnified bone windows. Maximum stone dimensions were recorded. For the in vivo portion of the study 41 patients with distal ureteral stones who underwent noncontrast computerized tomography and subsequently spontaneously passed the stones were analyzed. All analyzed stones were 100% calcium oxalate monohydrate or mixed, calcium based stones. Stones were prospectively collected at the clinic and the largest diameter was measured with digital calipers as the gold standard. This was compared to computerized tomography measurements using 4.0x magnified soft tissue windows and 4.0x magnified bone windows. Statistical comparisons were performed using Pearson's correlation and paired t test. In the in vitro portion of the study the most accurate measurements were obtained using 5.13x magnified bone windows with a mean 0.13 mm difference from caliper measurement (p = 0.6). Measurements performed in the soft tissue window with and without magnification, and in the bone window without magnification were significantly different from hand caliper measurements (mean difference 1.2, 1.9 and 1.4 mm, p = 0.003, <0.001 and 0.0002, respectively). When comparing measurement errors between stones of different composition in vitro, the error for calcium oxalate calculi was significantly different from the gold standard for all methods except bone window settings with magnification. For uric acid calculi the measurement error was observed only in standard soft tissue window settings. In vivo 4.0x magnified bone windows was superior to 4.0x magnified soft tissue windows in measurement accuracy. Magnified bone window measurements were not statistically different from digital caliper measurements (mean underestimation vs digital caliper 0.3 mm, p = 0.4), while magnified soft tissue windows were statistically distinct (mean underestimation 1.4 mm, p = 0.001). In this study magnified bone windows were the most accurate method of stone measurements in vitro and in vivo. Therefore, we recommend the routine use of magnified bone windows for computerized tomography measurement of stones. In vitro the measurement error in calcium oxalate stones was greater than that in uric acid stones, suggesting that stone composition may be responsible for measurement inaccuracies.

Bladder stone management: an update.

PubMed

Cicione, Antonio; DE Nunzio, Cosimo; Manno, Stefano; Damiano, Rocco; Posti, Alessandro; Lima, Estevao; Tubaro, Andrea; Balloni, Filippo

2018-02-01

Bladder stone (BS) is a rare disease curable with several options. Herein, we reviewed the specific literature in order to update the current BS management. A comprehensive systematic MEDLINE search was performed for English language reports published before April 2017 using the BS related terms, i.e. bladder-vesical calculi, lithotripsy. Then manuscripts references were screened to identify unfounded studies. Studies regarding BS in children were excluded. Retrieved studies were classified according to their main item as: etiology, diagnosis, treatment, treatment in specific illnesses and advances in BS management. Treatment option was mainly related to stone size and number as well as concomitant causative disease. However, stone nature was not analyzed in all the retrieved studies. Both trans-urethral and percutaneous lithotripsy were efficacy for stone fragmentation although the last one was suggested to avoid urethral injuries. Holmiun:Yag laser lithotripsy has made stone fragmentation feasible by using local anesthesia however in selected patients only. The urological dogma to perform concomitant prostate surgery in men with BS has been recently questioned by some observational case-series studies however, the lack of randomization and long follow up preserve that knowledge. Bladder stone is a rare and ancient disease. Nowadays new technologies have been developed in the effort to make less invasive stone treatment. The retrieved studies show that stone fragmentation can be archived by using several surgical approaches and devices whereas comparative randomized studies are still unavailable to identify the best option.

A Guideline for the Management of Renal Stones in Astronauts

NASA Technical Reports Server (NTRS)

Reyes, David; Locke, James; Johnston, Smith

2014-01-01

There are no specific guidelines for the management of renal stones in astronauts. Given the increased risk for bone loss, hypercalcuria, and stone formation due to microgravity, a clinical practice guideline is needed. Methods An extensive review of the literature and current aeromedical standards for the management of renal stones was done. The NASA Flight Medicine Clinic's electronic medical record and Longitudinal Survey of Astronaut Health were also reviewed. This information was used to create an algorithm for the management of renal stones in astronauts. Results Guidelines are proposed based on accepted standards of care, with consideration to the environment of spaceflight. In a usual medical setting, asymptomatic, small stones less than 7 mm are often observed over time. Given the constraints of schedule, and the risks to crew health and mission, this approach is too liberal. An upper limit of 3 mm stone diameter was adopted before requiring intervention, because this is the largest size that has a significant chance of spontaneous passage on its own. Other specific guidelines were also created. Discussion The spaceflight environment requires more aggressive treatment than would otherwise be found with the usual practice of medicine. A small stone can become a major problem because it may ultimately require medical evacuation from orbit. Thus renal stones are a significant mission threat and should be managed in a systematic way to mitigate risks to crew health and mission success.

Operational features of decorative concrete

NASA Astrophysics Data System (ADS)

Bazhenova, Olga; Kotelnikov, Maxim

2018-03-01

This article deals with the questions of creation and use of decorative and finishing concrete and mortar. It has been revealed that the most effective artificial rock-imitating stone materials are those made of decorative concrete with the opened internal structure of material. At the same time it is important that the particles of decorative aggregate should be distributed evenly in the concrete volume. It can be reached only at a continuous grain-size analysis of the aggregate from the given rock. The article tackles the necessity of natural stone materials imitation for the cement stone color to correspond to the color of the rock. The possibility of creation of the decorative concrete imitating rocks in the high-speed turbulent mixer is considered. Dependences of durability and frost resistance of the studied concrete on the pore size and character and also parameters characterizing crack resistance of concrete are received.

Outcome of ureteroscopy for stone disease in patients with horseshoe kidney: Review of world literature.

PubMed

Ishii, Hiro; Rai, Bhavan; Traxer, Olivier; Kata, Slawomir G; Somani, Bhaskar K

2015-01-01

The management of urolithiasis in patients with horseshoe kidney (HSK) is difficult. Stone formation occurred in 1:5 patients with HSK due to impaired urinary drainage and infections. Percutaneous nephrolithotomy and shock wave lithotripsy can be technically challenging due to altered anatomy. We conducted a systematic review of the literature to look at the role of ureteroscopy for stone management in these patients. We searched MEDLINE, PubMed and the Cochrane Library from January 1990 to April 2013 for results of ureteroscopy and stone treatment in HSK patients. Inclusion criteria were all English language articles reporting on ureteroscopy in patients with HSK. Data were extracted on the outcomes and complications. A total of 3 studies was identified during this period. Forty-one patients with HSK underwent flexible ureteroscopy and stone treatment. The mean age was 42 with a male:female ratio nearly 3:1. The mean stone size was 16 mm (range: 3-35 mm). The mean operating time was 86 min with multiple stones seen in 15 patients. All 41 patients had a ureteral access sheath used and flexible ureteroscopy and holmium laser fragmentation done. Thirty-two (78%) patients were stone-free with a mean hospital stay of 1-day. Minor complications (Clavien I or II) were seen in 13 (32%) of which 6 had stent discomfort, 3 needed intravenous antibiotics for <24 h, 3 had hematuria of which 2 needed blood transfusion and one had pyelonephritis needing re-admission and antibiotics. There were no major complications found in the review. Retrograde stone treatment using ureteroscopy and lasertripsy in HSK patients can be performed with good stone clearance rate, but with a slightly higher complication rate. This procedure should, therefore, be done in high volume stone center with an experienced stone surgeon/team.

CT Texture Analysis of Ex Vivo Renal Stones Predicts Ease of Fragmentation with Shockwave Lithotripsy.

PubMed

Cui, Helen W; Devlies, Wout; Ravenscroft, Samuel; Heers, Hendrik; Freidin, Andrew J; Cleveland, Robin O; Ganeshan, Balaji; Turney, Benjamin W

2017-07-01

Understanding the factors affecting success of extracorporeal shockwave lithotripsy (SWL) would improve informed decision-making on the most appropriate treatment modality for an individual patient. Although stone size and skin-to-stone distance do correlate with fragmentation efficacy, it has been shown that stone composition and architecture, as reflected by structural heterogeneity on CT, are also important factors. This study aims to determine if CT texture analysis (CTTA), a novel, nondestructive, and objective tool that generates statistical metrics reflecting stone heterogeneity, could have utility in predicting likelihood of SWL success. Seven spontaneously passed, intact renal tract stones, were scanned ex vivo using standard CT KUB and micro-CT. The stones were then fragmented in vitro using a clinical lithotripter, after which, chemical composition analysis was performed. CTTA was used to generate a number of metrics that were correlated to the number of shocks needed to fragment the stone. CTTA metrics reflected stone characteristics and composition, and predicted ease of SWL fragmentation. The strongest correlation with number of shocks required to fragment the stone was mean Hounsfield unit (HU) density (r = 0.806, p = 0.028) and a CTTA metric measuring the entropy of the pixel distribution of the stone image (r = 0.804, p = 0.039). Using multiple linear regression analysis, the best model showed that CTTA metrics of entropy and kurtosis could predict 92% of the outcome of number of shocks needed to fragment the stone. This was superior to using stone volume or density. CTTA metrics entropy and kurtosis have been shown in this experimental ex vivo setting to strongly predict fragmentation by SWL. This warrants further investigation in a larger clinical study for the contribution of CT textural metrics as a measure of stone heterogeneity, along with other known clinical factors, to predict likelihood of SWL success.

Can ureteral stones cause pain without causing hydronephrosis?

PubMed

Song, Yan; Hernandez, Natalia; Gee, Michael S; Noble, Vicki E; Eisner, Brian H

2016-09-01

While computerized tomography (CT) is the gold standard for diagnosis of ureterolithiasis, ultrasound is a less costly and radiation-free alternative which is commonly used to evaluate patients with ureteral colic. The purpose of this study was to evaluate the frequency with which patients with ureteral stones and renal colic demonstrate hydronephrosis in order to better understand the evaluation of these patients. Two hundred and forty-eight consecutive patients presenting with ureteral colic and diagnosed with a single unilateral ureteral stone on CT scan in an urban tertiary care emergency department were retrospectively reviewed. Radiology reports were reviewed for stone size, diagnosis, and degree of hydronephrosis. Of the 248 patients evaluated for suspected ureteral stone, 221 (89.1 %) demonstrated any hydronephrosis, while 27 (10.9 %) did not. Hydronephrosis grade, available in 194 patients, was as follows: mild-70.6 %, moderate-27.8 %, and severe-1.5 %. Mean patient age was 47.0 years (SD 15.5), gender distribution was 35.9 % female and 64.1 % male, and mean stone axial diameter was 4.1 mm (SD 2.4). Stone location was as follows: ureteropelvic junction-4.1 %, proximal ureter-21 %, distal ureter-24.9 %, and ureterovesical junction-47.1 %. Axial stone diameter and coronal length (craniocaudal) were both significant predictors of degree of hydronephrosis (ANOVA, p < 0.001 for both). Age (ANOVA, p = NS), stone location (Chi square, p = NS), and gender (Chi square, p = NS) were not associated with degree of hydronephrosis. In patients with ureteral stones and colic, nearly 11 % do not demonstrate any hydronephrosis and a majority (nearly 71 %) will demonstrate only mild hydronephrosis. Stone diameter appears to be related to degree of hydronephrosis, whereas age, gender, and stone location are not. The lower incidence of hydronephrosis for small stones causing renal colic may explain the lower diagnostic accuracy of ultrasound when compared to CT for detecting ureteral stones.

The relationship between serum and urinary Fetuin-A levels and kidney stone formation among kidney stone patients.

PubMed

Mehrsai, Abdolrasoul; Guitynavard, Fateme; Nikoobakht, Mohammad Reza; Gooran, Shahram; Ahmadi, Ayat

2017-01-01

Mineralization inhibitors are required to prevent the precipitation of minerals and inhibit the formation of kidney stones and other ectopic calcifications. In laboratory studies, Fetuin-A as a glycoprotein has inhibited hydroxyapatite precipitation in calcium and phosphate supersaturated solutions; however, information about patients with kidney stones is limited. The aim of this study was to investigate the association of serum and urinary Fetuin-A levels with calcium oxalate kidney stones. In this case-control study, 30 patients with kidney stones and 30 healthy individuals without any history of urolithiasis who were referred to the urology ward of Sina Hospital of Tehran, Iran, in 2015 were entered into the study. All patients underwent computerized tomography scans. After collecting demographic information, serum and urine levels of Fetuin-A and some other calcification inhibitors and promoters, were measured and compared using T-test, Mann-Whitney and logistic regression between the two study groups. Patients with kidney stones, on average, had lower levels of Serum Fetuin-A (1522.27 ±755.39 vs. 1914.64 ±733.76 μg/ml; P = 0.046) as well as lower levels of Urine Fetuin-A (944.62 ±188.5 vs. 1409.68 ±295.26 μg/ml; P <0.001). Multivariate logistic analysis showed that urinary calcium and serum creatinine are the risk factors and Fetuin-A is a urinary protective factor for kidney stones. PFC Our study showed that patients with kidney stones had lower serum and urinary levels of Fetuin-A. In the logistic regression model, urinary Fetuin-A was reported as a protective factor for kidney stones.

Focused ultrasound to expel calculi from the kidney: safety and efficacy of a clinical prototype device.

PubMed

Harper, Jonathan D; Sorensen, Mathew D; Cunitz, Bryan W; Wang, Yak-Nam; Simon, Julianna C; Starr, Frank; Paun, Marla; Dunmire, Barbrina; Liggitt, H Denny; Evan, Andrew P; McAteer, James A; Hsi, Ryan S; Bailey, Michael R

2013-09-01

Focused ultrasound has the potential to expel small stones or residual stone fragments from the kidney, or move obstructing stones to a nonobstructing location. We evaluated the efficacy and safety of ultrasonic propulsion in a live porcine model. Calcium oxalate monohydrate kidney stones and laboratory model stones (2 to 8 mm) were ureteroscopically implanted in the renal pelvicalyceal system of 12 kidneys in a total of 8 domestic swine. Transcutaneous ultrasonic propulsion was performed using an HDI C5-2 imaging transducer (ATL/Philips, Bothell, Washington) and the Verasonics® diagnostic ultrasound platform. Successful stone relocation was defined as stone movement from the calyx to the renal pelvis, ureteropelvic junction or proximal ureter. Efficacy and procedure time was determined. Three blinded experts evaluated histological injury to the kidney in the control, sham treatment and treatment arms. All 26 stones were observed to move during treatment and 17 (65%) were relocated successfully to the renal pelvis (3), ureteropelvic junction (2) or ureter (12). Average ± SD successful procedure time was 14 ± 8 minutes and a mean of 23 ± 16 ultrasound bursts, each about 1 second in duration, were required. There was no evidence of gross or histological injury to the renal parenchyma in kidneys exposed to 20 bursts (1 second in duration at 33-second intervals) at the same output (2,400 W/cm(2)) used to push stones. Noninvasive transcutaneous ultrasonic propulsion is a safe, effective and time efficient means to relocate calyceal stones to the renal pelvis, ureteropelvic junction or ureter. This technology holds promise as a useful adjunct to surgical management for renal calculi. Copyright © 2013 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Prevalence and spot urine risk factors for renal stones in children taking topiramate.

PubMed

Corbin Bush, Nicol; Twombley, Katherine; Ahn, Justin; Oliveira, Carlos; Arnold, Susan; Maalouf, Naim M; Sakhaee, Khashayar

2013-12-01

Topiramate (TPM), an anti-epileptic drug with >4 million users, increases renal stones in adults. We screened outpatient TPM-treated children without history of stones to estimate the prevalence of renal stones and to characterize urine stone-risk profiles. Children taking TPM ≥1 month underwent an interview, renal ultrasound, and spot urine testing in this prospective study. Normal spot urine values were defined as: calcium/creatinine ratio ≤0.20 mg/mg (>12 months) or ≤0.60 mg/mg (≤12 months), citrate/creatinine ratio >0.50 mg/mg, and pH ≤ 6.7. Of 41 patients with average age of 9.2 years (range 0.5-18.7), mean TPM dose of 8.0 mg/kg/day (range 1.4-23.6), and mean treatment duration of 27 months (range 1-112), two (4.9%) had renal stones. The majority of children taking TPM had lithogenic abnormalities on spot urine testing, including 21 (51%) with hypercalciuria, 38 (93%) with hypocitraturia, and 28 (68%) with pH ≥ 6.7. Hypercalciuria and hypocitraturia were independent of TPM dose and duration; urine pH increased with dose. 24-h urine parameters improved in 1 stone-former once TPM was weaned. Asymptomatic stones were found in 2/41 (4.8%) children taking TPM. Risk factors for stones were present in the spot urine of most children, including hypocitraturia (93%) and hypercalciuria (51%), independent of TPM dose and duration. High urine pH, found in 68%, correlated with TPM dose. Pediatric specialists should be aware of increased risks for stones, hypercalciuria, hypocitraturia, and alkaline urine in children taking TPM. Published by Elsevier Ltd.

Focused Ultrasound to Expel Calculi from the Kidney: Safety and Efficacy of a Clinical Prototype Device

PubMed Central

Harper, Jonathan D.; Sorensen, Mathew D.; Cunitz, Bryan W.; Wang, Yak-Nam; Simon, Julianna C.; Starr, Frank; Paun, Marla; Dunmire, Barbrina; Liggitt, H. Denny; Evan, Andrew P.; McAteer, James A.; Hsi, Ryan S.; Bailey, Michael R.

2015-01-01

Purpose Focused ultrasound has the potential to expel small stones or residual stone fragments from the kidney, or move obstructing stones to a nonobstructing location. We evaluated the efficacy and safety of ultrasonic propulsion in a live porcine model. Materials and Methods Calcium oxalate monohydrate kidney stones and laboratory model stones (2 to 8 mm) were ureteroscopically implanted in the renal pelvicalyceal system of 12 kidneys in a total of 8 domestic swine. Transcutaneous ultrasonic propulsion was performed using an HDI C5-2 imaging transducer (ATL/Philips, Bothell, Washington) and the Verasonics® diagnostic ultrasound platform. Successful stone relocation was defined as stone movement from the calyx to the renal pelvis, ureteropelvic junction or proximal ureter. Efficacy and procedure time was determined. Three blinded experts evaluated histological injury to the kidney in the control, sham treatment and treatment arms. Results All 26 stones were observed to move during treatment and 17 (65%) were relocated successfully to the renal pelvis (3), ureteropelvic junction (2) or ureter (12). Average ± SD successful procedure time was 14 ± 8 minutes and a mean of 23 ± 16 ultrasound bursts, each about 1 second in duration, were required. There was no evidence of gross or histological injury to the renal parenchyma in kidneys exposed to 20 bursts (1 second in duration at 33-second intervals) at the same output (2,400 W/cm2) used to push stones. Conclusions Noninvasive transcutaneous ultrasonic propulsion is a safe, effective and time efficient means to relocate calyceal stones to the renal pelvis, ureteropelvic junction or ureter. This technology holds promise as a useful adjunct to surgical management for renal calculi. PMID:23583535

Pigment gallstone pathogenesis: slime production by biliary bacteria is more important than beta-glucuronidase production.

PubMed

Stewart, L; Ponce, R; Oesterle, A L; Griffiss, J M; Way, L W

2000-01-01

Pigment stones are thought to form as a result of deconjugation of bilirubin by bacterial beta-glucuronidase, which results in precipitation of calcium bilirubinate. Calcium bilirubinate is then aggregated into stones by an anionic glycoprotein. Slime (glycocalyx), an anionic glycoprotein produced by bacteria causing foreign body infections, has been implicated in the formation of the precipitate that blocks biliary stents. We previously showed that bacteria are present within the pigment portions of gallstones and postulated a bacterial role in pigment stone formation through beta-glucuronidase or slime production. Ninety-one biliary bacterial isolates from 61 patients and 12 control stool organisms were tested for their production of beta-glucuronidase and slime. The average slime production was 42 for biliary bacteria and 2.5 for stool bacteria (P <0.001). Overall, 73% of biliary bacteria and 8% of stool bacteria produced slime (optical density >3). In contrast, only 38% of biliary bacteria produced beta-glucuronidase. Eighty-two percent of all patients, 90% of patients with common bile duct (CBD) stones, 100% of patients with primary CBD stones, and 93% of patients with biliary tubes had one or more bacterial species in their stones that produced slime. By comparison, only 47% of all patients, 60% of patients with CBD stones, 62% of patients with primary CBD stones, and 50% of patients with biliary tubes had one or more bacteria that produced beta-glucuronidase. Most biliary bacteria produced slime, and slime production correlated better than beta-glucuronidase production did with stone formation and the presence of biliary tubes or stents. Patients with primary CBD stones and biliary tubes had the highest incidence of slime production. These findings suggest that bacterial slime is important in gallstone formation and the blockage of biliary tubes.

Flexible Ureteroscopic Management of Horseshoe Kidney Renal Calculi

PubMed Central

Ding, Jie; Huang, Yunteng; Gu, Siping; Chen, Yifan; Peng, Jie; Bai, Qiang; Ye, Min; Qi, Jun

2015-01-01

ABSTRACT Purpose: To evaluate the clinical efficacy of flexible ureteroscope (F-URS) combined with holmium laser lithotripter in treating renal calculi in horseshoe kidney. Materials and Methods: From November 2010 to December 2013, the medical history and charts of sixteen patients (mean age 42.9±11.6 years, range 26-66 years), including 13 males and 3 females were analyzed retrospectively. Mean stone burden was 29±8 mm (range 17-42 mm2). Mean stone digitized surface area (DSA) was 321±94 mm2 (range 180-538 mm2). Under spinal anesthesia in a modified lithotomy position with the head down, rigid ureteroscope was placed firstly into the ureter to reach the level of the pelvis, a zebra guide wire was inserted and following the removal of the rigid ureteroscope, an ureteral access sheath was positioned along the guide wire, then passed the URF P-5 flexible ureteroscope into the renal cavities over the guidewire. After locating the stones, holmium laser lithotripsy was performed. Results: The average operative time was 92±16 minutes (range 74-127 min.). No major complications were encountered. Ten patients obtained stone-free status with one session, four obtained stone-free status after two sessions. Single session stone-free rate was 62.5%, overall stone-free rate was 87.5%. Two patients have small residual stones in the lower pole. Conclusions: F-URS combined with holmium laser lithotripter and nitinol basket, is safe and effective in dealing with moderate stone diameter (<30 mm) in HSKs with high clearance rates and low complication rates. PMID:26401860

Methylated purines in urinary stones.

PubMed

Safranow, Krzysztof; Machoy, Zygmunt

2005-08-01

The aim of the study was to measure the content of methylated purines that appear as admixtures in uric acid stones. We analyzed urinary calculi from 48 residents of Western Pomerania who underwent surgery at the urology ward in Szczecin. Stone samples were dissolved in 0.1 mol/L NaOH. Extracts were diluted in 50 mmol/L KH(2)PO(4) and analyzed by reversed-phase HPLC with ultraviolet detection and use of a gradient of methanol concentration and pH. Uric acid was the main component of 9 stones. All 9 showed admixtures of 9 other purine derivatives: endogenous purine breakdown products (xanthine, hypoxanthine, and 2,8-dihydroxyadenine) and exogenous methyl derivatives of uric acid and xanthine (1-, 3-, and 7-methyluric acid; 1,3-dimethyluric acid; and 3- and 7-methylxanthine). Amounts of these purine derivatives ranged from the limit of detection to 12 mg/g of stone weight and showed a strong positive correlation (Spearman rank correlation coefficients, 0.63-0.94) with the uric acid content of the samples. The main methylated purine in the stones was 1-methyluric acid. Urinary purines at concentrations below their saturation limits may coprecipitate in samples supersaturated with uric acid and appear as admixtures in urinary stones. The amount of each purine depends on its average urinary excretion, similarity to the chemical structure of uric acid, and concentration of the latter in the stone. These findings suggest that purines in stones represent a substitutional solid solution with uric acid as solvent. Methylxanthines, which are ubiquitous components of the diet, drugs, and uric acid calculi, may be involved in the pathogenesis of urolithiasis.

Comparison of the outcomes of complete supine percutaneous nephrolithotomy in patients with radiopaque and radiolucent kidney stones

PubMed Central

Falahatkar, Siavash; Mokhtari, Gholamreza; Amin, Atiyeh; Kazemnezhad, Ehsan; Esmaeili, Samaneh; Herfeh, Nadia Rastjou; Falahatkar, Reza

2017-01-01

Objective This study compared the stone opacity effect in patients who had radiopaque and radiolucent stones in percutaneous nephrolithotomy (PCNL) results. Material and methods The medical records of 171 complete supine PCNL procedures were gathered. Patients were categorized into two groups: those with radiopaque (n=141) and those with radiolucent (n=30) stones. Kidney, ureter and bladder x-ray was done a day after PCNL and Ultrasound imaging was done two weeks later to evaluate the stone free rate. A stone free result was defined as having less than 4 mm residual stone size. Outcome parameters were compared by univariate analysis and those which were significantly different between the two groups were assessed by multivariate binary logistic regression analysis. Results There were no significant differences in age, sex, body mass index, hypertension, diabetes mellitus, pre-surgery hemoglobin, pre-surgery serum creatinine, stone and also surgery-related parameters between the two groups. Stone free rate, surgery time, complication-related parameters, hemoglobin drop, serum creatinine and glomerular filtration rate (GFR) changes were similar in both groups based on univariate analysis. The radiopaque group had higher post-surgery GFR (p=0.04) and longer hospital stay (p=0.009). However, opacity had no effect on these outcomes after multivariate analysis. Higher post-surgery GFR was seen in patient with higher GFR before surgery (p<0.0001). Also, higher hemoglobin before surgery was correlated with less hospital stay (p=0.001). Conclusion The complete supine percutaneous nephrolithotomy outcomes are similar in patients with radiopaque and radiolucent stones. PMID:29201513

Comparison of the outcomes of complete supine percutaneous nephrolithotomy in patients with radiopaque and radiolucent kidney stones.

PubMed

Falahatkar, Siavash; Mokhtari, Gholamreza; Amin, Atiyeh; Kazemnezhad, Ehsan; Esmaeili, Samaneh; Herfeh, Nadia Rastjou; Falahatkar, Reza

2017-12-01

This study compared the stone opacity effect in patients who had radiopaque and radiolucent stones in percutaneous nephrolithotomy (PCNL) results. The medical records of 171 complete supine PCNL procedures were gathered. Patients were categorized into two groups: those with radiopaque (n=141) and those with radiolucent (n=30) stones. Kidney, ureter and bladder x-ray was done a day after PCNL and Ultrasound imaging was done two weeks later to evaluate the stone free rate. A stone free result was defined as having less than 4 mm residual stone size. Outcome parameters were compared by univariate analysis and those which were significantly different between the two groups were assessed by multivariate binary logistic regression analysis. There were no significant differences in age, sex, body mass index, hypertension, diabetes mellitus, pre-surgery hemoglobin, pre-surgery serum creatinine, stone and also surgery-related parameters between the two groups. Stone free rate, surgery time, complication-related parameters, hemoglobin drop, serum creatinine and glomerular filtration rate (GFR) changes were similar in both groups based on univariate analysis. The radiopaque group had higher post-surgery GFR (p=0.04) and longer hospital stay (p=0.009). However, opacity had no effect on these outcomes after multivariate analysis. Higher post-surgery GFR was seen in patient with higher GFR before surgery (p<0.0001). Also, higher hemoglobin before surgery was correlated with less hospital stay (p=0.001). The complete supine percutaneous nephrolithotomy outcomes are similar in patients with radiopaque and radiolucent stones.

Treatment of pouch stones after augmentation ileocystoplasty in children: is it always bothersome?

PubMed

Helmy, Tamer E; Elawdy, Mohammed M; AbdelHalim, Ahmed; Orban, Hesham; Nabeeh, Hossam; Dawaba, Mohammed; Hafez, Ashraf T

2015-01-01

To report our experience with different approaches for management of pouch stones in children with ileal-based urinary reservoir. Charts of children who underwent ileal-based urinary reservoirs between 2000 and 2009 were retrospectively reviewed. Patients who were diagnosed with reservoir calculi were identified; medical records were reviewed for patients' demographics, diversion details, stone criteria, mode of treatment, perioperative complications, and recurrence rate. We identified 26 children with pouch stones after urinary diversion. There were 11 boys (42%) and 15 girls (58%). Mean age was 11 years (range, 4-16 years). Mean time for diagnosis was 42 months (24-120 months). Pouch stones were asymptomatic in 10 patients (38%). Fifteen cases were postbladder augmentation and 11 cases postcontinent cutaneous diversion. The mean stone size was 4 cm (range, 1-10 cm), and mean Hounsfield Unit was 585 (205-1090). Seventeen children (65%) had positive urine culture result, whereas 9 children were sterile. Seven children (27%) required open poucholithotomy, whereas 19 patients (73%) were managed endoscopically. Percutaneous approach was done in 5 children, whereas urethral access was used in 7 children. Mechanical extraction was performed in 12 cases, and stone disintegration was required in 7 cases. Eight children developed stone recurrence. Mean time for recurrence was 11 months (range, 3-19 months). Six children were after endoscopic disintegration, and all required redo endoscopic extraction. Stone analysis was available in 15 patients (struvite stones in 10 cases and calcium phosphate in 5 cases). Pouch stones are established long-term complication of urinary diversion. Open and endoscopic approaches are valid treatment strategies. Copyright © 2015 Elsevier Inc. All rights reserved.

Feasibility and safety of bilateral same-session flexible ureteroscopy (FURS) for renal and ureteral stone disease

PubMed Central

Drake, Tamsin; Ali, Ahmed

2015-01-01

Introduction With rising incidence of urolithiasis, treatment of stones (both symptomatic and asymptomatic) in multiple locations including bilateral stones can be controversial and challenging. We report our experience and treatment outcomes in patients undergoing bilateral, same-session ureterorenoscopy (BS-URS) for bilateral ureteric and/or renal calculi, and discuss the advantages and disadvantages of such procedures. Material and methods Between May 2012 and October 2013, 251 patients underwent ureteroscopic surgery for stone disease at our institution. Of these, 21 patients underwent 25 bilateral same-session ureterorenoscopy (BS-URS) procedures during this period. Stone-free status was defined as endoscopically stone-free or radiological fragments <2 mm. Results The mean bilateral stone size was 21mm (range: 4-63 mm) with a mean operating time of 70 minutes (range 35-129 minutes). Fifteen procedures (60%) were done as day case procedures with a mean stay of 0.9 days (range 0-7 days). Of the 42 renal units treated, 80% (34/42) were stone-free after a single bilateral ureteroscopy session. A further 12% (5/42) were cleared after a re-look procedure making the overall stone free rate 92.8% (39/42). There were no major complications and 3 minor complications (2 early stent removals due to stent symptoms and 1 pyelonephritis requiring intravenous antibiotics). Conclusions Bilateral same-session ureteroscopy is a safe and effective treatment option for patients with bilateral ureteric and/or renal calculi, even with stones in multiple locations and increasing stone loads. However, as with all surgery, proper patient and equipment selection is crucial in terms of reducing complication rates and improving treatment outcomes. PMID:26251740

Percutaneous nephrolithotomy in hypertensive patients with different sizes of instruments.

PubMed

Resorlu, B; Kara, C; Ozyuvali, E; Unsal, A

2011-01-01

The risk of major complications, especially hemorrhage, is significantly elevated during surgery in hypertensive patients. To determine whether percutaneous nephrolithotomy (PCNL) can be safely performed in the hypertensive patients using different sized instruments. We reviewed the records of 602 patients undergoing PCNL at our institution and identified 53 who were on antihypertensive therapy at the time of surgery. Patients were categorized into three groups according to size of devices used in surgery : those 24 F percutaneous tract with 22 F nephroscope (Group 1, n = 12 [22.7%]; 26 F percutaneous tract with 24 F nephroscope (Group 2, n = 19 [35.8%]) and 30 F percutaneous tract with 26 F nephroscope (Group 3, n = 22 [41.5%]). We compared the groups with regard to baseline characteristics, intraoperative parameters, stone-free and complication rates, and the length of hospitalization. There were no differences between the three groups in age, gender, weight and stone laterality. Fluoroscopy time, access to the collecting system and mean operative time for per cm2 stone did not differ between the groups. Hemoglobin decrease, postoperative hospital stay and blood transfusion rate was higher in group 3. Stones were completely cleared in 83.3%, 84.2% and 81.3% of patients, which increased to 91.6%, 89.5%, and 90.1% with adjunctive therapy in the group 1,2 and 3, respectively. PCNL with smaller devices is a safe and effective method in hypertensive patients. It has significantly a shorter hospital stay and less bleeding rates compared to classical PCNL.

Four years follow-up of 101 children with melamine-related urinary stones.

PubMed

Yang, Li; Wen, Jian Guo; Wen, Jian Jun; Su, Zhi Qiang; Zhu, Wen; Huang, Chen Xu; Yu, Si Long; Guo, Zhan

2013-06-01

The melamine-contaminated milk powder incidence occurred in China in 2008. Many studies have been published regarding the epidemiology, clinical symptoms, diagnosis and treatment of melamine-related urinary stones. The objective of this study is to follow-up the effects of melamine-contaminated milk powder consumption on kidney and body growth in children with melamine-related urinary stones 4 years ago. One hundred and one children with melamine-related urinary stones were followed up by urinalysis, renal function tests and urinary ultrasonography. The data of body weight and height, clinical signs and complications were collected. Eighty normal children without the history of consuming melamine-contaminated milk powder were collected as controls. Eighty-one children with melamine-related urinary stones were successfully followed up. Of 45 cases with melamine-related urinary stones treated conservatively after discharge, 34 disappeared completely, 6 dissolved partially, 1 increased in size and 4 did not change at 4 years follow-up. The percentages of under-height and under-weight infants were significantly higher in melamine-related urinary stones group compared to the controls, respectively (p < 0.05). Routine blood, renal and bladder function tests as well as urinalysis were normal in all children. No urological tumors were detected. No noticeable impact of melamine-related urinary stones on kidney and bladder was found at 4 years follow-up. However, whether or not melamine-related urinary stones had effect on body growth needs follow-up in future.

IL-6 does not predict current urolithiasis in stone formers.

PubMed

Rieder, Jocelyn M; Nisbet, Alan A; Lesser, Timothy; Franke, Ethan I; Brusky, John P; Parekh, Ashish R; Kaptein, John; Bellman, Gary C

2008-10-01

Interleukin-6 (IL-6), an inflammatory marker, has previously been found to be elevated in the urine of patients with urolithiasis. Oxalate and other stone precursors have been shown to increase IL-6 production in proximal tubular epithelial cells in vitro. We examined whether urinary IL-6 could be used as a screening test to determine current urolithiasis in individuals who are known to form urinary stones. Thirty-five adult patients with current urolithiasis demonstrated on imaging were enrolled in the study. Exclusion criteria included disease known to elevate IL-6. Each patient provided a pre-treatment urine specimen and one month after proven to be stone-free an additional urine specimen was obtained. The urinary IL-6/creatinine ratio was determined for both specimens and compared. Ten patients provided both specimens. The mean pre-operative urinary IL-6/creatinine ratio before the procedure was 1.63 pg/mL. The mean post procedure urinary IL-6/creatinine ratio after the patient was confirmed to be stone-free was 1.81 pg/mL. These were not significantly different (p=0.38). Preoperative urinary IL-6/creatinine ratio did not correlate to stone size (r=0.15) and no correlation was seen between time from treatment and stone free IL-6/creatinine ratio (r=0.48). Urinary IL-6 is not a good screening test for current urolithiasis in stone-forming individuals. It is elevated whether the stone is present or not.

Effect of Ferrous Additives on Magnesia Stone Hydration

NASA Astrophysics Data System (ADS)

Zimich, V.

2017-11-01

The article deals with the modification of the magnesia binder with additives containing two- and three-valent iron cations which could be embedded in the chloromagnesium stone structure and also increase the strength from 60 MPa in a non-additive stone to 80MPa, water resistance from 0.58 for clear stone to 0.8 and reduce the hygroscopicity from 8% in the non-additive stone to 2% in the modified chloromagnesium stone. It is proposed to use the iron hydroxide sol as an additive in the quantities of up to 1% of the weight of the binder. The studies were carried out using the modern analysis methods: the differentialthermal and X-ray phase analysis. The structure was studied with an electron microscope with an X-ray microanalyzer. A two-factor plan-experiment was designed which allowed constructing mathematical models characterizing the influence of variable factors, such as the density of the zatcher and the amount of sol in the binder, on the basic properties of the magnesian stone. The result of the research was the magnesia stone with the claimed properties and formed from minerals characteristic for magnesian materials as well as additionally formed from amachenite and goethite. It has been established that a highly active iron hydroxide sol the ion sizes of which are commensurate with magnesium ions is actively incorporated into the structure of pentahydroxychloride and magnesium hydroxide changing the habit of crystals compacting the structure of the stone and changing its hygroscopicity.

Treatment of ureteric calculi--use of Holmium: YAG laser lithotripsy versus pneumatic lithoclast.

PubMed

Tipu, Salman Ahmed; Malik, Hammad Afzal; Mohhayuddin, Nazim; Sultan, Gauhar; Hussain, Manzoor; Hashmi, Altaf; Naqvi, Syed Ali Anwar; Rizvi, Syed Adibul Hasan

2007-09-01

To compare the efficacy of Holmium: YAG laser and pneumatic lithoclast in treating ureteric calculi. The study included total of 100 patients divided into two equal groups of laser lithotripsy (LL) and pneumatic lithoclast (PL). Study was conducted between September 2006 and February 2007. Inclusion criteria were patients with a ureteric stone of size 1-2 cm and negative urine culture. An x-ray KUB was mandatory. IVU and CT pyelogram were also done when required. Procedures were done under general anaesthesia after a single dose of pre-operative antibiotic. A 7.5 Fr semi rigid ureteroscope was used for ureteroscopy in all cases. Holmium: YAG laser with 365 microm wide probe was employed in laser group and frequency was set between 5 and 10 Hz at a power of 10 to 15 W. Swiss lithoclast with single or multiple fire technique was used accordingly in PL group. Postoperatively patients underwent radiography and helical CT as required at 4th week of follow up to asses stone clearance. The mean patient age in LL and PL group was 38 +/- 10 and 40 +/- 10 years respectively. The male to female ratio and stone size were similar between the groups. Stone migration up in pelvicalyceal system occurred in two patients of LL group while in eight patients of PL group. JJ Stent was placed in 5(10%) patients in laser group where as 13 (26%) patients required it in pneumatic lithoclast group. Stone free rate at 4 weeks was 92% in laser group as compared to 82% in pneumatic lithoclast group. Hospital stay was more than 24 hours in 2 patients of laser group as compared to 5 patients of pneumatic lithoclast group. Complication rate was 4% in LL group whereas it was 14% in PL group. Holmium: YAG laser lithotripsy is a superior technology compared to pneumatic lithoclast in terms of rate of stone clearance and complications, especially in upper ureteric stones.

A New Alternative for Difficult Ureter in Adult Patients: No Need to Dilate Ureter via a Balloon or a Stent with the Aid of 4.5F Semirigid Ureteroscope.

PubMed

Söylemez, Haluk; Yıldırım, Kadir; Utangac, Mehmet Mazhar; Aydoğan, Tahsin Batuhan; Ezer, Mehmet; Atar, Murat

2016-06-01

To investigate the effectivity of 4.5F ultrathin ureteroscope (UT-URS) without any need for active or passive dilation in the treatment of adult patient population in whom ureteral orifices cannot be engaged using conventional URS. Among a total of 512 adult patients who had undergone URS between April 2012 and November 2015 in our department for diagnostic or therapeutic purposes, 43 (8.4%) patients required ureteral dilation because we could not engage ureteral orifice. In adult patients in whom we could not engage ureteral orifice with 7.5F and 8F semirigid URS, we tried to complete the operation using 4.5F UT-URS without resorting to dilation. Age and gender of the patients, indication for operation, stone size, location, operative times, laterality of stone(s), stone-free rates, length of hospital stay, and complications were recorded. Mean age of the patients was 34.5 ± 11.2 (21-66) years. The patients had undergone operations for ureteral stone (n = 39), unexplained hydronephrosis (n = 2), and ureteral stenosis (n = 2). Mean stone size was 8.2 ± 2.3 (4-18) mm. Mean operative time was 64.2 ± 13.5 minutes. In 37 of 39 patients, a complete stone-free rate (94.8%) was achieved. Mean length of hospital stay was 8.9 ± 5.8 hours. It has been demonstrated that in an adult patient population in whom ureteral orifices cannot be engaged using conventional URS, ureteral access could be achieved with 4.5F UT-URS without any need for dilation. At the same time, use of 4.5F UT-URS resulted in an acceptable treatment success and lower complication rates in most of these patients without the need for a second session.

A Prospective Randomized Comparison Between Laparoscopic Ureterolithotomy and Semirigid Ureteroscopy for Upper Ureteral Stones >2 cm: A Single-Center Experience.

PubMed

Kumar, Anup; Vasudeva, Pawan; Nanda, Biswajit; Kumar, Niraj; Jha, Sanjeev Kumar; Singh, Harbinder

2015-11-01

The optimal management method of upper ureteral stones >2 cm is still a challenge. We performed a prospective randomized comparison between laparoscopic ureterolithotomy (LU) and ureteroscopic lithotripsy for upper ureteral calculus >2 cm to evaluate safety and efficacy of both procedures. Between January 2010 and May 2012, 110 patients with a single radiopaque upper ureteral calculus >2 cm were included in the present study. Randomization was done in two groups-group A: LU was performed and group B: Ureteroscopy (URS) was performed using a 6/7.5F semirigid ureteroscope (Richard Wolf) with holmium laser intracorporeal lithotripsy. Statistical analysis was performed regarding demographic profile, success, retreatment, auxiliary procedure rates, and also complications. Out of the total 110 patients, 54 patients were enrolled in group A and 56 patients were enrolled in group B. Mean stone size was 2.3±0.2 cm in group A versus 2.2±0.1 cm in group B (p=0.52). The overall 3-month stone-free rate was (50/50) 100% for group A versus (38/50) 76% for group B (p=0.02). The retreatment rate was significantly greater in group B than group A (8% vs. 0%, respectively; (p=0.01). Auxiliary procedure rate was higher in group B than in group A (26% vs. 0% respectively; p=0.001). The complication rate was 12% in group A versus 26% in group B (p=0.001). For upper ureteral stones of size greater than 2 cm, LU has a greater stone clearance rate, comparable operating time, lesser need for auxiliary procedure, and complication rate as compared to URS.

Prognostic Impact of Stone-Scoring Systems After Percutaneous Nephrolithotomy for Staghorn Calculi: A Single Center's Experience Over 10 Years.

PubMed

Choi, Sae Woong; Bae, Woong Jin; Ha, U-Syn; Hong, Sung-Hoo; Lee, Ji Youl; Kim, Sae Woong; Cho, Hyuk Jin

2016-09-01

To investigate the prognostic factors associated with stone-free rate (SFR) and complications after percutaneous nephrolithotomy (PCNL) for the treatment of staghorn stone and to compare the predictive value and accuracy of three stone-scoring systems for the treatment success of staghorn stone. We retrospectively reviewed all patients undergoing PCNL at our center from June 2003 to June 2014. On the basis of noncontrast computed tomography (NCCT) scan images, we calculated Guy's score, S.T.O.N.E. nephrolithometry, and Clinical Research Office of the Endourological Society (CROES) nomogram to assess the association with stone-free status and complications. For statistical evaluation, univariate and multivariate logistic regression analyses were used. During the study period, 886 cases had medical records available. Cases who underwent PCNL for the treatment of staghorn calculi accounted for 34.4% (305/886 cases). Preoperative NCCT was performed in 217 cases. The 217 procedures (205 patients, 12 simultaneous bilateral PCNLs) had a mean stone size of 1358.3 ± 760.7 mm(2), with 111 (51.2%) partial staghorn and 106 (48.8%) complete staghorn stones. The initial and overall SFRs of PCNL were 53.9% and 70.1%, respectively. The overall complication rate was 32.7% (71/217 cases). On a multivariate logistic regression analysis, independent predictors for SFR were number of involved calices, S.T.O.N.E. nephrolithometry, and pre-existent urinary tract infection (UTI) (odds ratios [ORs] = 1.311, 1.933, and 2.340, respectively). Stone burden was an independent risk factor for the development of complications on multivariate analysis (OR = 2.846 and p = 0.001). The results of this study show that multiple involved calices, high grades of S.T.O.N.E. nephrolithometry, and pre-existent UTIs were associated with lower SFR after PCNL for staghorn calculi. Stone burden was an independent risk factor for the development of complications.

Prospective Comparative Study of the Efficacy and Safety of New-Generation Versus First-Generation System for Super-Mini-Percutaneous Nephrolithotomy: A Revolutionary Approach to Improve Endoscopic Vision and Stone Removal.

PubMed

Zeng, Guohua; Zhu, Wei; Liu, Yang; Fan, Junhong; Lam, Wayne; Lan, Yu; Cai, Chao; Deng, Tuo; Li, Xiaohang; Zhao, Zhijian

2017-11-01

The study sought to compare the procedural and clinical results of super-mini-percutaneous nephrolithotomy (SMP) with the use of first- and new-generation devices. A prospective, comparative cohort study was carried out between February 2013 and January 2017. Patients who underwent either first- or new-generation SMP were eligible for the study. Inclusion criteria were adult patients with renal stone <4 cm, or in pediatric patients with renal stone <2.5 cm with a history of failed extracorporeal shockwave lithotripsy. The primary outcome of the present study was the operating time, which was calculated from the starting of percutaneous puncture to the wound closure. Secondary outcomes were the stone-free rate (SFR), blood loss (hemoglobin decrease), hospital stay, and postoperative complications. One hundred fifty-six consecutive patients who underwent SMP for treatment of renal stones were eligible for the study, with the first 85 patients undergoing SMP with the first-generation device, and the remaining 71 consecutive patients being treated with the new-generation SMP system. The two groups of patients had comparable demographic data, including age, BMI, stone size, Guy's score, stone location, comorbidities, grade of hydronephrosis, and history of urinary tract infection. The new-generation SMP had a shorter operation time (39.3 vs 50.5 min, p = 0.016) and shorter postoperative hospitalization time (2.1 vs 3.0 days, p < 0.001) than the first-generation SMP. No significant difference existed between the two groups for SFR, hemoglobin decrease, and tubeless rate. The overall operative complication rates using the Clavien-Dindo grading system were similar between the two cohorts of patients. The clinical outcomes of the new-generation SMP in patients with moderate-sized renal stone were comparable when compared with the first-generation SMP. New-generation SMP system using an irrigation/suction sheath improved intraoperative irrigation, a more efficient hydrodynamic mechanism for retrieval of fragments. This may account for the shorter operative time than the first-generation SMP system demonstrated in this study.

The 1980 Archeological Investigations at the Big Hill Lake, Kansas.

DTIC Science & Technology

1980-01-01

implements as plano -convex scrapers. The modified flake categories are comprised of those specimens which exhibit edge alterations resulting from...stone projectile points, chipped stone blades, polished celts and gorgets, cut deer mandibles, an incised canine tooth and grinding and milling...are characteristic at this Middle Ceramic group of sites, along with plano -convex end scrapers and medium to small-sized projectile points. 31 Many

Percutaneous nephrolithotomy versus retrograde intrarenal surgery for the treatment of kidney stones up to 2 cm in patients with solitary kidney: a single centre experience.

PubMed

Bai, Yunjin; Wang, Xiaoming; Yang, Yubo; Han, Ping; Wang, Jia

2017-01-18

To compare the treatment outcomes between percutaneous nephrolithotomy (PCNL) and retrograde intrarenal surgery (RIRS) for the management of stones larger than 2 cm in patients with solitary kidney. One hundred sixteen patients with a solitary kidney who underwent RIRS (n = 56) or PCNL (n = 60) for large renal stones (>2 cm) between Jan 2010 and Nov 2015 have been considered. The patients' characteristics, stone characteristics, operative time, incidence of complications, hospital stay, and stone-free rates (SFR) have been evaluated. SFRs after one session were 19.6% and 35.7% for RIRS and PCNL respectively (p = 0.047), but the SFR at 3 months follow-up comparable in both groups (82.1% vs. 88.3%, p = 0.346). The calculated mean operative time for RIRS was longer (p < 0.001), but the mean postoperatively hospital stay was statistically significantly shorter (p < 0.001) and average drop in hemoglobin level was less (p = 0.040). PCNL showed a higher complication rate, although this difference was not statistically significant. Satisfactory stone clearance can be achieved with multi-session RIRS in the treatment of renal stones larger than 2 cm in patients with solitary kidney. RIRS can be considered as an alternative to PCNL in selected cases.

A biological stone from a medieval cemetery in Poland.

PubMed

Gładykowska-Rzeczycka, Judyta J; Nowakowski, Dariusz

2014-01-01

A review of the literature shows that origination of biological stones as well as their pathogenesis mostly depend on the environmental factors. As a result, the structural spectrum of such calculi and their chemical composition are highly diversified. It is well known that biological stones are formed mostly in the digestive and urinary tracts. However, it has been demonstrated that this kind of stony structure can be also, though rarely, found in circulatory and reproductive systems, skin, mucosa, and tear ducts. Although in palaeopathology, the list of biological stones is enriched by stony tumours and/or discharges, it is very difficult to uncover the small size deposits in excavation material. In the literature such findings, originating from different countries and centuries, are few. The described stone was found among the bones of an adult individual in the medieval cemetery of Gdańsk (Poland). The SEM, X-ray spectrometer and chemical evaluation revealed that it was a bladder calculus.

A Biological Stone from a Medieval Cemetery in Poland

PubMed Central

Gładykowska-Rzeczycka, Judyta J.; Nowakowski, Dariusz

2014-01-01

A review of the literature shows that origination of biological stones as well as their pathogenesis mostly depend on the environmental factors. As a result, the structural spectrum of such calculi and their chemical composition are highly diversified. It is well known that biological stones are formed mostly in the digestive and urinary tracts. However, it has been demonstrated that this kind of stony structure can be also, though rarely, found in circulatory and reproductive systems, skin, mucosa, and tear ducts. Although in palaeopathology, the list of biological stones is enriched by stony tumours and/or discharges, it is very difficult to uncover the small size deposits in excavation material. In the literature such findings, originating from different countries and centuries, are few. The described stone was found among the bones of an adult individual in the medieval cemetery of Gdańsk (Poland). The SEM, X-ray spectrometer and chemical evaluation revealed that it was a bladder calculus. PMID:25275551

Impact of pulse duration on Ho:YAG laser lithotripsy: fragmentation and dusting performance.

PubMed

Bader, Markus J; Pongratz, Thomas; Khoder, Wael; Stief, Christian G; Herrmann, Thomas; Nagele, Udo; Sroka, Ronald

2015-04-01

In vitro investigations of Ho:YAG laser-induced stone fragmentation were performed to identify potential impacts of different pulse durations on stone fragmentation characteristics. A Ho:YAG laser system (Swiss LaserClast, EMS S.A., Nyon, Switzerland) with selectable long or short pulse mode was tested with regard to its fragmentation and laser hardware compatibility properties. The pulse duration is depending on the specific laser parameters. Fragmentation tests (hand-held, hands-free, single-pulse-induced crater) on artificial BEGO stones were performed under reproducible experimental conditions (fibre sizes: 365 and 200 µm; laser settings: 10 W through combinations of 0.5, 1, 2 J/pulse and 20, 10, 5 Hz, respectively). Differences in fragmentation rates between the two pulse duration regimes were detected with statistical significance for defined settings. Hand-held and motivated Ho:YAG laser-assisted fragmentation of BEGO stones showed no significant difference between short pulse mode and long pulse mode, neither in fragmentation rates nor in number of fragments and fragment sizes. Similarly, the results of the hands-free fragmentation tests (with and without anti-repulsion device) showed no statistical differences between long pulse and short pulse modes. The study showed that fragmentation rates for long and short pulse durations at identical power settings remain at a comparable level. Longer holmium laser pulse duration reduces stone pushback. Therefore, longer laser pulses may result in better clinical outcome of laser lithotripsy and more convenient handling during clinical use without compromising fragmentation effectiveness.

Ruschita Romanian marble - 130 years of official exploitation and 130 m depth of architectural beauty around the word

NASA Astrophysics Data System (ADS)

Cetean, Valentina

2013-04-01

Developed in a large metamorphic area, the marble deposit from Ruschita perimeter is the most important Romanian source for ornamental stone, the old quarry being operative since 1883. The closest locality offer the commercial name also, identical with the geological one as is defined in the technical referentials and in the denomination European standard. Ruschita is also an active quarry, developed by step-by-step expansion in depth (the initial extraction reached 130 m depth), but also in the adjacent areas. The important height of the open deposit offered the possibility to the owner, MARMOSIM SA, to apply an experimental extraction method, by underground mining. It is the only Romanian place, and few in the world, where this spectacular mining element can be found for dimension stone. The extraction gallery was built starting from the lower level of the old quarry and allowed obtaining nicer and bigger blocks. The Ruschita marble is a metamorphic stone with high crystallinity and medium size of crystals (until 0.2-0.5 mm). Has the basic colour from white and grey to pink, with many intermediary nuances generally given by grey veins and less by impurities from internal structure. The stone present irregular break, sometimes following the very narrow internal discontinuities, invisible at macroscopic analyse. The main physical - mechanical characteristics are presented below: Characteristic M.U. Value Apparent density Kg/m3 2680 - 2720 Water absorption % 0.12 - 0.21 Capillarity g/m2.s0,5 0.130-0.218 Porosity % 0.30 - 0.74 Compression strength N/mm2 85 - 120 Flexural strength MPa 15-18 Rupture energy J 5 Coefficient of frost cleftness % 10 -14 Abrasion resistance - Bohme cm3/50cm2 17-18 Salt crystallization % 0.1 Nowadays, the extraction in the Ruschita area is achieved by equipments from Dazzini, Fantini, Pellegrini, Korfamann, Caterpillar, Volvo and Komatsu. The average volume of blocks is bigger than 10-12 m2. The Ruschita marble can be easily cut at size and the slabs being used both for inside and the outside application: from flooring, walling, stairs, solid masonry units, capitals, plinths, fireplaces, kitchen tops (even if not-recommended because is not resistant to acids), tablet, architectural elements, until paving and flooring works, elements in contact with the floor, non-vertical surfaces etc. A bigger attention has to be paid for using of Ruschita marble at external facades in those regions with many freezing - thaw cycles per year with big differences between the lower and higher value of temperature, because the stone can suffer important damage due to the different thermal dilatation coefficient. In this case, the recommended thickness of panels is bigger than 2 cm, the lustre final polishing The Dom from Milano - known as into a continuously maintenance work in the last 500 years - was partially rebuilt in the '70ties with Ruschita marble. Another interesting places where this marble was used are: the Parliament buildings from Wien (Austria) and Budapest (Hungary), BBC centre from Menheim (Germany), architectural elements from Michael Schumacher's villa from Monte Carlo or the bathrooms from sultan's palace in Brunei. Similar to other type of marbles used as in the ornamental stone industry, Ruschita type combines the specific colour with the internal structure, qualitative properties and unique ornamental characteristics. All these are decisive elements recommend the Ruschita marble as candidates for "Global Heritage Stone Resource" designation.

Therapeutic effects of visual standard channel combined with F4.8 visual puncture super-mini percutaneous nephrolithotomy on multiple renal calculi.

PubMed

Cui, Zhenyu; Gao, Yanjun; Yang, Wenzeng; Zhao, Chunli; Ma, Tao; Shi, Xiaoqiang

2018-01-01

To evaluate the therapeutic effects of visual standard channel combined with F4.8 visual puncture super-mini percutaneous nephrolithotomy (SMP) on multiple renal calculi. The clinical data of 46 patients with multiple renal calculi treated in Affiliated Hospital of Hebei University from October 2015 to September 2016 were retrospectively analyzed. There were 28 males and 18 females aged from 25 to 65 years old, with an average of 42.6. The stone diameters were 3.0-5.2 cm, (4.3 ± 0.8) cm on average. F4.8 visual puncture-assisted balloon expansion was used to establish a standard channel. After visible stones were removed through nephroscopy combined with ultrasound lithotripsy, the stones of other parts were treated through F4.8 visual puncture SMP with holmium laser. Indices such as the total time of channel establishment, surgical time, decreased value of hemoglobin, phase-I stone clearance rate and surgical complications were summarized. Single standard channel was successfully established in all cases with the assistance of F4.8 visual puncture, of whom 24 were combined with a single microchannel, 16 were combined with double microchannels, and six were combined with three microchannels. All patients were placed with nephrostomy tube which was not placed in the microchannels. Both F5 double J tubes were placed after surgery. The time for establishing a standard channel through F4.8 visual puncture was (6.8 ± 1.8) min, and that for establishing a single F4.8 visual puncture microchannel was (4.5 ± 0.9) min. The surgical time was (92 ± 15) min. The phase-I stone clearance rate was 91.3% (42/46), and the decreased value of hemoglobin was (12.21 ± 2.5) g/L. There were 8 cases of postoperative fever which was relieved after anti-inflammatory treatment. Four cases had 0.5-0.8 cm of stone residue in the lower calyx, and all stones were discharged one month after surgery by in vitro shock wave lithotripsy combined with position nephrolithotomy, without stone streets, delayed bleeding, peripheral organ damage or urethral injury. Combining visual standard channel with F4.8 visual puncture SMP for the treatment of multiple renal calculi had the advantages of reducing the number of large channels, high rate of stone clearance, safety and reliability and mild complications. The established F4.8 visual puncture channel was safer and more accurate.

Prospective comparative study of miniperc and standard PNL for treatment of 1 to 2 cm size renal stone.

PubMed

Mishra, Shashikant; Sharma, Rajan; Garg, Chandrapraksh; Kurien, Abraham; Sabnis, Ravindra; Desai, Mahesh

2011-09-01

• To evaluate the results of miniperc vis-à-vis standard PNL in the treatment of stones of 1-2 cm in size. Miniperc may represent a reasonable procedure in patients with nonbulky urolithiasis offering a similar outcome as standard percutaneous nephrolithotomy (PNL) with advantage of reduced morbidity. • 55 procedures including 27 miniperc and 28 standard PNL were performed for renal stones 1-2 cm in size. Pediatric patient, active urinary tract infection, renal malformation, uncorrected coagulopathy and morbid obesity patients were excluded from the study. • The parameters studied were demography, operative time, postoperative analgesic requirement, hemoglobin drop, complications and stone clearance. • Mean tract size was 18.2 ± 2 F (15-20) and 26.8 ± 2 F (24-30), P value <0.0001 in the miniperc and standard PNL, respectively. Holmium LASER and pneumatic lithotripter were the main energy sources used in miniperc and standard PNL, respectively. • Miniperc operative time was longer than that of standard PNL (45.2 ± 12.6 vs 31 ± 16.6 min, P= 0.0008 respectively). • Conversely, there was an advantage of miniperc over standard PNL in terms of a significantly reduced hemoglobin drop (0.8 ± 0.9 vs 1.3 ± 0.4 gram%, P= 0.01), analgesic requirement (55.4 ± 50 vs 70.2 ± 52 mg tramadol, P= 0.29) and hospital stay (3.2 ± 0.8 vs 4.8 ± 0.6 days, P ≤ 0.001), respectively. • Intra- operative conversion of the procedure into a tubeless PNL was significantly more in the miniperc group (P ≤ 0.001). The miniperc and standard PNL group had clearance rates of 96% and 100%, respectively at 1 month follow up. • This study demonstrated significant advantages of the miniperc procedure in terms of reduced bleeding leading to a tubeless procedure and reduced hospital stay. • The stone free rates and the complications were similar in either group. © 2011 THE AUTHORS. BJU INTERNATIONAL © 2011 BJU INTERNATIONAL.

Predicting the stone composition of children preoperatively by Hounsfield unit detection on non-contrast computed tomography.

PubMed

Altan, Mesut; Çitamak, Burak; Bozaci, Ali Cansu; Güneş, Altan; Doğan, Hasan Serkan; Haliloğlu, Mithat; Tekgül, Serdar

2017-10-01

Many studies have been performed on adult patients to reveal the relationship between Hounsfield unit (HU) value and composition of stone, but none have focused on childhood. We aimed to predict stone composition by HU properties in pre-intervention non-contrast computed tomography (NCCT) in children. This could help to orient patients towards more successful interventions. Data of 94 children, whose pre-intervention NCCT and post-interventional stone analysis were available were included. Stones were grouped into three groups: calcium oxalate (CaOx), cystine, and struvite. Besides spot urine PH value, core HU, periphery HU, and Hounsfield density (HUD) values were measured and groups were compared statistically. The mean age of patients was 7 ± 4 (2-17) years and the female/male ratio was 51/43. The mean stone size was 11.7 ± 5 (4-24) mm. There were 50, 38, and 6 patients in the CaOx, cystine, and struvite groups, respectively. The median values for core HU, periphery HU, and mean HU in the CaOx group were significantly higher than the corresponding median values in the cystine and struvite groups. Significant median HUD difference was seen only between the CaOx and cystine groups. No difference was seen between the cystine and struvite groups in terms of HU parameters. To distinguish these groups, mean spot urine PH values were compared and were found to be higher in the struvite group than the cystine group (Table). The retrospective nature and small number of patients in some groups are limitations of this study, which also does not include all stone compositions. Our cystine stone rate was higher than childhood stone composition distribution in the literature. This is because our center is a reference center in a region with high recurrence rates of cystine stones. In fact, high numbers of cystine stones helped us to compare them with calcium stones more accurately and became an advantage for this study. NCCT at diagnosis can provide some information for determination of stone composition. While CaOx stones can be discriminated from cystine and struvite stones using HU parameters, a simple spot urine pH assessment must be added to distinguish cystine stones from struvite stones. Copyright © 2017 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

Mineral resources of Novokuznetsk administrative district of Kemerovo region (metallic and non-metallic minerals)

NASA Astrophysics Data System (ADS)

Gutak, Ja M.

2017-09-01

The article summarizes data on metallic and non-metallic minerals of Novokuznetsk district of Kemerovo region. Consistently reviewed are iron deposits (Tersinskaya group of deposits), gold deposits (placer accumulations and vein gold deposits), mineral water deposits (Tersinskoe deposit), deposit of refractory clay (Barkinskoe) and wide spread mineral deposits such as brick clay, keramzite materials, sand and gravel, building stones, ornamental stones, facing stones, peat, materials for lime production. It is indicated that resource base of metallic and nonmetallic minerals is inferior to that of mineral coal. At the same time it can be of considerable interest to small and medium-size businesses as objects with quick return of investment (facing and ornamental stones). For a number of wide spread mineral resources (brick clay, keramzite materials, sand and gravel) it is an important component of local industry.

Internet search trends analysis tools can provide real-time data on kidney stone disease in the United States.

PubMed

Willard, Scott D; Nguyen, Mike M

2013-01-01

To evaluate the utility of using Internet search trends data to estimate kidney stone occurrence and understand the priorities of patients with kidney stones. Internet search trends data represent a unique resource for monitoring population self-reported illness and health information-seeking behavior. The Google Insights for Search analysis tool was used to study searches related to kidney stones, with each search term returning a search volume index (SVI) according to the search frequency relative to the total search volume. SVIs for the term, "kidney stones," were compiled by location and time parameters and compared with the published weather and stone prevalence data. Linear regression analysis was performed to determine the association of the search interest score with known epidemiologic variations in kidney stone disease, including latitude, temperature, season, and state. The frequency of the related search terms was categorized by theme and qualitatively analyzed. The SVI correlated significantly with established kidney stone epidemiologic predictors. The SVI correlated with the state latitude (R-squared=0.25; P<.001), the state mean annual temperature (R-squared=0.24; P<.001), and state combined sex prevalence (R-squared=0.25; P<.001). Female prevalence correlated more strongly than did male prevalence (R-squared=0.37; P<.001, and R-squared=0.17; P=.003, respectively). The national SVI correlated strongly with the average U.S. temperature by month (R-squared=0.54; P=.007). The search term ranking suggested that Internet users are most interested in the diagnosis, followed by etiology, infections, and treatment. Geographic and temporal variability in kidney stone disease appear to be accurately reflected in Internet search trends data. Internet search trends data might have broader applications for epidemiologic and urologic research. Copyright © 2013 Elsevier Inc. All rights reserved.

Urinary tract stone occurrence in the Women's Health Initiative (WHI) randomized clinical trial of calcium and vitamin D supplements.

PubMed

Wallace, Robert B; Wactawski-Wende, Jean; O'Sullivan, Mary Jo; Larson, Joseph C; Cochrane, Barbara; Gass, Margery; Masaki, Kamal

2011-07-01

The Women's Health Initiative (WHI) randomized clinical trial (RCT) of calcium plus vitamin D (CaD) supplements found a 17% excess in urinary tract stone incidence in the supplemented group. This study evaluated whether this risk is modified by participant characteristics. We examined the correlates of urinary tract stone occurrence in the CaD arm of the WHI trial. We analyzed an RCT involving 36,282 postmenopausal women aged 50-79 y from 40 WHI centers: 18,176 women received 500 mg calcium carbonate plus 200 IU vitamin D(3) twice daily (1000 mg and 400 IU daily, respectively), and 18,106 women received a matching placebo for an average of 7.0 y. The incidence of urinary tract stones was determined. The incidence of self-reported clinically diagnosed urinary tract stones was more common in the active CaD medication group than in the placebo group (hazard ratio: 1.17; 95% CI: 1.02, 1.34): 449 women in the CaD group and 381 women in the placebo group reported a stone during the trial. The rates of self-reported stones did not differ between various demographic, anthropomorphic, dietary, and other hypothesized risk factors according to randomization assignment. Neither the total calcium intake nor the use of calcium supplements at baseline was associated with the risk of stones. In sensitivity analyses that censored participants who were below 80% adherence, the findings were similar. Daily supplementation with CaD for 7 y was associated with an increase in the number of self-reported urinary tract stones. These findings have implications for CaD supplement use. This trial was registered with the WHI at clinicaltrials.gov as NCT00000611.

Urinary tract stone occurrence in the Women's Health Initiative (WHI) randomized clinical trial of calcium and vitamin D supplements123

PubMed Central

Wallace, Robert B; Wactawski-Wende, Jean; O'Sullivan, Mary Jo; Larson, Joseph C; Cochrane, Barbara; Gass, Margery; Masaki, Kamal

2011-01-01

Background: The Women's Health Initiative (WHI) randomized clinical trial (RCT) of calcium plus vitamin D (CaD) supplements found a 17% excess in urinary tract stone incidence in the supplemented group. This study evaluated whether this risk is modified by participant characteristics. Objective: We examined the correlates of urinary tract stone occurrence in the CaD arm of the WHI trial. Design: We analyzed an RCT involving 36,282 postmenopausal women aged 50–79 y from 40 WHI centers: 18,176 women received 500 mg calcium carbonate plus 200 IU vitamin D3 twice daily (1000 mg and 400 IU daily, respectively), and 18,106 women received a matching placebo for an average of 7.0 y. The incidence of urinary tract stones was determined. Results: The incidence of self-reported clinically diagnosed urinary tract stones was more common in the active CaD medication group than in the placebo group (hazard ratio: 1.17; 95% CI: 1.02, 1.34): 449 women in the CaD group and 381 women in the placebo group reported a stone during the trial. The rates of self-reported stones did not differ between various demographic, anthropomorphic, dietary, and other hypothesized risk factors according to randomization assignment. Neither the total calcium intake nor the use of calcium supplements at baseline was associated with the risk of stones. In sensitivity analyses that censored participants who were below 80% adherence, the findings were similar. Conclusions: Daily supplementation with CaD for 7 y was associated with an increase in the number of self-reported urinary tract stones. These findings have implications for CaD supplement use. This trial was registered with the WHI at clinicaltrials.gov as NCT00000611. PMID:21525191

Body Mass Index and Kidney Stones: A Cohort Study of Japanese Men

PubMed Central

Yoshimura, Eiichi; Sawada, Susumu S.; Lee, I-Min; Gando, Yuko; Kamada, Masamitsu; Matsushita, Munehiro; Kawakami, Ryoko; Ando, Ryosuke; Okamoto, Takashi; Tsukamoto, Koji; Miyachi, Motohiko; Blair, Steven N.

2016-01-01

Background In Japan, the incidence of kidney stones has increased markedly in recent decades. Major causes of kidney stones remain unclear, and limited data are available on the relationship between overweight/obesity and the incidence of kidney stones. We therefore evaluated body mass index (BMI) and the incidence of kidney stones in Japanese men. Methods Of the workers at a gas company, 5984 males aged 20–40 years underwent a medical examination in 1985 (baseline). This study includes 4074 of the men, who were free of kidney stones at baseline and underwent a second medical examination performed between April 2004 and March 2005. BMI was calculated from measured height and weight in 1985, and men were categorized into tertiles. The development of kidney stones during follow-up was based on self-reports from questionnaires at the second medical examination. Results The average duration of follow-up was 19 years, with 258 participants developing kidney stones during this period. Using the lowest BMI (1st tertile) group as a reference, the hazard ratios (95% confidence intervals [CIs]) for the 2nd and 3rd BMI tertiles were: 1.26 (95% CI, 0.92–1.73) and 1.44 (95% CI, 1.06–1.96), respectively (P for trend = 0.019). After additionally adjusting for potential confounders, such as age, systolic blood pressure, cardiorespiratory fitness, cigarette smoking, and alcohol consumption, the hazard ratios were 1.28 (95% CI, 0.93–1.76) and 1.41 (95% CI, 1.02–1.97), respectively (P for trend = 0.041). Conclusions These results suggest that increased BMI is a risk factor for kidney stones in Japanese men. PMID:26616396

Body Mass Index and Kidney Stones: A Cohort Study of Japanese Men.

PubMed

Yoshimura, Eiichi; Sawada, Susumu S; Lee, I-Min; Gando, Yuko; Kamada, Masamitsu; Matsushita, Munehiro; Kawakami, Ryoko; Ando, Ryosuke; Okamoto, Takashi; Tsukamoto, Koji; Miyachi, Motohiko; Blair, Steven N

2016-01-01

In Japan, the incidence of kidney stones has increased markedly in recent decades. Major causes of kidney stones remain unclear, and limited data are available on the relationship between overweight/obesity and the incidence of kidney stones. We therefore evaluated body mass index (BMI) and the incidence of kidney stones in Japanese men. Of the workers at a gas company, 5984 males aged 20-40 years underwent a medical examination in 1985 (baseline). This study includes 4074 of the men, who were free of kidney stones at baseline and underwent a second medical examination performed between April 2004 and March 2005. BMI was calculated from measured height and weight in 1985, and men were categorized into tertiles. The development of kidney stones during follow-up was based on self-reports from questionnaires at the second medical examination. The average duration of follow-up was 19 years, with 258 participants developing kidney stones during this period. Using the lowest BMI (1st tertile) group as a reference, the hazard ratios (95% confidence intervals [CIs]) for the 2nd and 3rd BMI tertiles were: 1.26 (95% CI, 0.92-1.73) and 1.44 (95% CI, 1.06-1.96), respectively (P for trend = 0.019). After additionally adjusting for potential confounders, such as age, systolic blood pressure, cardiorespiratory fitness, cigarette smoking, and alcohol consumption, the hazard ratios were 1.28 (95% CI, 0.93-1.76) and 1.41 (95% CI, 1.02-1.97), respectively (P for trend = 0.041). These results suggest that increased BMI is a risk factor for kidney stones in Japanese men.

Minimally invasive percutaneous nephrolithotomy: an effective treatment for kidney stones in infants under 1 year of age. A single-center experience.

PubMed

Dağgülli, Mansur; Sancaktutar, Ahmet Ali; Dede, Onur; Utanğaç, Mehmet Mazhar; Bodakçi, Mehmet Nuri; Penbegül, Necmettin; Hatipoğlu, Namık Kemal; Çakmakçı, Süleyman

2015-11-01

We aimed to present the outcomes of PNL surgery performed in infantile patients with small renal stones who were younger than 1 year of age. A single-center prospective trial was initiated and during the period between Jan 2013 and Jan 2015, PNL was applied to 20 renal units of 16 infants (6 girls and 10 boys), including 4 patients with bilateral kidney stones. PNL was performed in patients with renal stones larger than 2 cm, as well as stones resistant to SWL or renal stones that were undetectable during SWL. The mean age of the patients was 9.55 (5-12) months. Of the 20 renal units, 1 had complete staghorn stones, 3 had partial staghorn stones, 13 had renal pelvic stones, and 3 had lower pole stones. The mean stone size was 18.5 mm (range 12-36 mm). Mean operative time for PNL was 88 (25-135 min). Mean fluoroscopy time was estimated as 3.4 min. Mean hemoglobin loss was 0.72 g/L (0.2-3). The mean hospital stay was 4.1 days (2-8 days). On postoperative day 1, a complete stone-free state was achieved in 70% of renal units (14 of 20). At the end of the first postoperative week, the remaining two patients had insignificant residual fragments of 3 mm and were followed conservatively without any specific intervention. Thus, the total SFR was 80% (16 of 20) at discharge. In infants aged less than 1 year, minimal access tract dilation during PNL, the use of smaller caliber pediatric instruments, and the realization of this procedure by surgeons with adequate experience in adults carry utmost importance. In addition, special care should be taken to avoid hypothermia and radiation exposure during PNL.

Safety and Effectiveness of a Longer Focal Beam and Burst Duration in Ultrasonic Propulsion for Repositioning Urinary Stones and Fragments.

PubMed

Janssen, Karmon M; Brand, Timothy C; Cunitz, Bryan W; Wang, Yak-Nam; Simon, Julianna C; Starr, Frank; Liggitt, H Denny; Thiel, Jeff; Sorensen, Mathew D; Harper, Jonathan D; Bailey, Michael R; Dunmire, Barbrina

2017-08-01

In the first-in-human trial of ultrasonic propulsion, subjects passed collections of residual stone fragments repositioned with a C5-2 probe. Here, effectiveness and safety in moving multiple fragments are compared between the C5-2 and a custom (SC-50) probe that produces a longer focal beam and burst duration. Effectiveness was quantified by the number of stones expelled from a calyx phantom consisting of a 30-mm deep, water-filled well in a block of tissue mimicking material. Each probe was positioned below the phantom to move stones against gravity. Single propulsion bursts of 50 ms or 3 s duration were applied to three separate targets: 10 fragments of 2 different sizes (1-2 and 2-3 mm) and a single 4 × 7 mm human stone. Safety studies consisted of porcine kidneys exposed to an extreme dose of 10-minute burst duration, including a 7-day survival study and acute studies with surgically implanted stones. Although successful in the clinical trial, the shorter focal beam and maximum 50 ms burst duration of the C5-2 probe moved stones, but did not expel any stones from the phantom's 30-mm deep calyx. The results were similar with the SC-50 probe under the same 50 ms burst duration. Longer (3 s) bursts available with the SC-50 probe expelled all stones at both 4.5 and 9.5 cm "skin-to-stone" depths with lower probe heating compared to the C5-2. No abnormal behavior, urine chemistry, serum chemistry, or histological findings were observed within the kidney or surrounding tissues for the 10 min burst duration used in the animal studies. A longer focal beam and burst duration improved expulsion of a stone and multiple stone fragments from a phantom over a broad range of clinically relevant penetration depths and did not cause kidney injury in animal studies.

Outcome of ureteroscopy for stone disease in patients with horseshoe kidney: Review of world literature

PubMed Central

Ishii, Hiro; Rai, Bhavan; Traxer, Olivier; Kata, Slawomir G.; Somani, Bhaskar K.

2015-01-01

Introduction and Objectives: The management of urolithiasis in patients with horseshoe kidney (HSK) is difficult. Stone formation occurred in 1:5 patients with HSK due to impaired urinary drainage and infections. Percutaneous nephrolithotomy and shock wave lithotripsy can be technically challenging due to altered anatomy. Materials and Methods: We conducted a systematic review of the literature to look at the role of ureteroscopy for stone management in these patients. We searched MEDLINE, PubMed and the Cochrane Library from January 1990 to April 2013 for results of ureteroscopy and stone treatment in HSK patients. Inclusion criteria were all English language articles reporting on ureteroscopy in patients with HSK. Data were extracted on the outcomes and complications. Results: A total of 3 studies was identified during this period. Forty-one patients with HSK underwent flexible ureteroscopy and stone treatment. The mean age was 42 with a male:female ratio nearly 3:1. The mean stone size was 16 mm (range: 3-35 mm). The mean operating time was 86 min with multiple stones seen in 15 patients. All 41 patients had a ureteral access sheath used and flexible ureteroscopy and holmium laser fragmentation done. Thirty-two (78%) patients were stone-free with a mean hospital stay of 1-day. Minor complications (Clavien I or II) were seen in 13 (32%) of which 6 had stent discomfort, 3 needed intravenous antibiotics for <24 h, 3 had hematuria of which 2 needed blood transfusion and one had pyelonephritis needing re-admission and antibiotics. There were no major complications found in the review. Conclusions: Retrograde stone treatment using ureteroscopy and lasertripsy in HSK patients can be performed with good stone clearance rate, but with a slightly higher complication rate. This procedure should, therefore, be done in high volume stone center with an experienced stone surgeon/team. PMID:26692667

Multiphase fluid-solid coupled analysis of shock-bubble-stone interaction in shockwave lithotripsy.

PubMed

Wang, Kevin G

2017-10-01

A novel multiphase fluid-solid-coupled computational framework is applied to investigate the interaction of a kidney stone immersed in liquid with a lithotripsy shock wave (LSW) and a gas bubble near the stone. The main objective is to elucidate the effects of a bubble in the shock path to the elastic and fracture behaviors of the stone. The computational framework couples a finite volume 2-phase computational fluid dynamics solver with a finite element computational solid dynamics solver. The surface of the stone is represented as a dynamic embedded boundary in the computational fluid dynamics solver. The evolution of the bubble surface is captured by solving the level set equation. The interface conditions at the surfaces of the stone and the bubble are enforced through the construction and solution of local fluid-solid and 2-fluid Riemann problems. This computational framework is first verified for 3 example problems including a 1D multimaterial Riemann problem, a 3D shock-stone interaction problem, and a 3D shock-bubble interaction problem. Next, a series of shock-bubble-stone-coupled simulations are presented. This study suggests that the dynamic response of a bubble to LSW varies dramatically depending on its initial size. Bubbles with an initial radius smaller than a threshold collapse within 1 μs after the passage of LSW, whereas larger bubbles do not. For a typical LSW generated by an electrohydraulic lithotripter (p max  = 35.0MPa, p min  =- 10.1MPa), this threshold is approximately 0.12mm. Moreover, this study suggests that a noncollapsing bubble imposes a negative effect on stone fracture as it shields part of the LSW from the stone. On the other hand, a collapsing bubble may promote fracture on the proximal surface of the stone, yet hinder fracture from stone interior. Copyright © 2016 John Wiley & Sons, Ltd.

Flexible Ureterorenoscopy versus Mini-Percutaneous Nephrolithotomy for the Treatment of Renal Stones.

PubMed

Ergin, Giray; Kirac, Mustafa; Kopru, Burak; Ebiloglu, Turgay; Biri, Hasan

2018-04-22

To compare the pain status and stone free rates of flexible ureterorenoscopy (F-URS) versus mini-percutaneousnephrolithotomy (mini-PNL) for the treatment of 1-to 2-cm renal stones. This study was retrospectively designed with match paired method. Between January 2013 and December 2016, 387 patients underwent stone surgery for renal stones, 45 patients underwent FURS and 45 patients underwent mini-PNL. 90 patients were divided into two groups according to the surgical procedures. Group 1 patients underwent F-URS, and Group 2 patients underwent mini-PNL. During the intraoperative andpostoperative periods, pain management for all patients was standardized. Pain scores were determined using a visual analogue scale (VAS) completed at 2, 6, 12 and 24 hours postoperatively. The stone free status, hemoglobin levels, fluoroscopy time (FT), operation time (OT), hospitalization time (HT), return to work time (RWT), and complications were noted for each patient. Of all patients, the mean age was 41.1 ± 12.1 years and the mean stone size was 13.9 ± 2.9 mm. The VAS scores were significantly higher in the mini-PNL group at 2, 6, 12 and 24 hours (P < .05). The stone-free status and complication rates were similar between the two groups (P > .05); however, the hemoglobin decreases and the fluoroscopy, operation, hospitalization and return to work times were higher in the mini-PNL group than in the F-URS group (P < .05). F-URS is less painful than mini-PNL for the treatment of 1- to 2-cm renal stones. However, the stone free rate is similar between the two procedures while mini-PNL is superior in terms of fluoroscopy, operation, hospitalization and return to work duration. We think that F-URS is more comfortable and less painful than mini-PNL and achieves a similar stone free rate for the treatment of 1- to 2-cm renal stones.

Comparison of miniaturized percutaneous nephrolithotomy and flexible ureterorenoscopy for moderate size renal stones in elderly patients.

PubMed

Ozgor, Faruk; Yanaral, Fatih; Savun, Metin; Ozdemir, Harun; Caglar, Ufuk; Sarilar, Omer

2018-06-01

Life expectancy has become longer, thus the number of elderly people who require treatment for nephrolithiasis has increased. We aimed to analyze the efficacy of flexible ureterorenoscopy (f-URS) and miniaturized percutaneous nephrolithotomy (mPNL) in the management of 10 and 30 mm renal stones in patients aged >60 years. In prospective non-randomized series, the data of patients who underwent f-URS or mPNL for kidney stones between July 2013 and July 2016 were analyzed. The procedure was accepted as successful if the patient was achieved complete stone clearance according to CT imaging between 1-3 months postoperatively. In total 60 patients and 58 patients were underwent f-URS and mPNL, respectively. The mean operation time, fluoroscopy time and hospitalization time were significantly shorter for the f-URS (p < 0.001, p < 0.001, p < 0.001, respectively). According to Clavien classification system, complication rates were not significantly different between the groups (p = 0.673). The stone-free rate was 81.7% for the f-URS group and 77.6% for the mPNL group after a single-session procedure (p = 0.747). Calcium oxalate monohydrate stones were the most common stone type in both groups. In multivariate analysis, multiple stones localization was only independent factor to predict complications. Our study had showed that both f-URS and mPNL are effective treatment modalities for 10-30-mm renal stones in elderly patients. Additionally, presence of stones in multiple location was the only predictive factor for complication development. Copyright © 2017 Kaohsiung Medical University. Published by Elsevier Taiwan. All rights reserved.

[Relational database for urinary stone ambulatory consultation. Assessment of initial outcomes].

PubMed

Sáenz Medina, J; Páez Borda, A; Crespo Martinez, L; Gómez Dos Santos, V; Barrado, C; Durán Poveda, M

2010-05-01

To create a relational database for monitoring lithiasic patients. We describe the architectural details and the initial results of the statistical analysis. Microsoft Access 2002 was used as template. Four different tables were constructed to gather demographic data (table 1), clinical and laboratory findings (table 2), stone features (table 3) and therapeutic approach (table 4). For a reliability analysis of the database the number of correctly stored data was gathered. To evaluate the performance of the database, a prospective analysis was conducted, from May 2004 to August 2009, on 171 stone free patients after treatment (EWSL, surgery or medical) from a total of 511 patients stored in the database. Lithiasic status (stone free or stone relapse) was used as primary end point, while demographic factors (age, gender), lithiasic history, upper urinary tract alterations and characteristics of the stone (side, location, composition and size) were considered as predictive factors. An univariate analysis was conducted initially by chi square test and supplemented by Kaplan Meier estimates for time to stone recurrence. A multiple Cox proportional hazards regression model was generated to jointly assess the prognostic value of the demographic factors and the predictive value of stones characteristics. For the reliability analysis 22,084 data were available corresponding to 702 consultations on 511 patients. Analysis of data showed a recurrence rate of 85.4% (146/171, median time to recurrence 608 days, range 70-1758). In the univariate and multivariate analysis, none of the factors under consideration had a significant effect on recurrence rate (p=ns). The relational database is useful for monitoring patients with urolithiasis. It allows easy control and update, as well as data storage for later use. The analysis conducted for its evaluation showed no influence of demographic factors and stone features on stone recurrence.

Usefulness of hounsfield unit and density in the assessment and treatment of urinary stones

PubMed Central

Gücük, Adnan; Üyetürk, Uğur

2014-01-01

Computed tomography (CT) is widely used to examine stones in the urinary system. In addition to the size and location of the stone and the overall health of the kidney, CT can also assess the density of the stone in Hounsfield units (HU). The HU, or Hounsfield density, measured by CT, is related to the density of the tissue or stone. A number of studies have assessed the use of HU in urology. HUs have been used to predict the type and opacity of stones during diagnosis, and the efficacy has been assessed using methods including extracorporeal shock wave lithotripsy (ESWL), percutaneous nephrolithotomy (PCNL), ureterorenoscopic ureterolithotripsy (URSL), and medical expulsive treatment (MET). Previous studies have focused on the success rate of HU for predicting the type of stone and of ESWL treatment. Understanding the composition of the stone plays a key role in determining the most appropriate treatment modality. The most recent reports have suggested that the HU value and its variants facilitate prediction of stone composition. However, the inclusion of data regarding urine, such as pH and presence of crystals, increases the predictive accuracy. HUs, which now form part of the clinical guidelines, allow us to predict the success of ESWL; therefore, they should be taken into account when ESWL is considered as a treatment option. However, there are currently insufficient data available regarding the value of HU for assessing the efficacy of PCNL, URSL, and MET. Studies performed to date suggest that these values would make a significant contribution to the diagnosis and treatment of urinary system stones. However, more data are required to assess this further. PMID:25374823

Flexible ureterorenoscopy for lower pole stones: influence of the collecting system's anatomy.

PubMed

Jessen, Jan Peter; Honeck, Patrick; Knoll, Thomas; Wendt-Nordahl, Gunnar

2014-02-01

The impact of renal anatomy on the success rate of flexible ureterorenoscopy (fURS) for lower pole stones is less clear than it is on shock wave lithotripsy, for which it is a recognized influence factor. We analyzed safety and efficiency of fURS using modern endoscopes for lower pole stones dependent on the collecting system's configuration. We retrospectively evaluated a consecutive sample of 111 fURS for lower pole stones at our tertiary care center between January 2010 and September 2012 from our prospectively kept database. All procedures were performed with modern flexible ureterorenoscopes, nitinol baskets, holmium laser lithotripsy, and ureteral access sheaths whenever needed. The infundibular length (IL) and width (IW) and infundibulopelvic angle (IPA) were measured and the data were stratified for stone-free status and complications classified by the Clavien-Dindo scale. Univariate and multifactorial statistical analyses were performed. Correlation of operation time (OR-time) with anatomical parameters was conducted. Ninety-eight (88.3%) of the 111 patients were stone free after a single fURS. On multifactorial analysis, the stone size and IL had significant influence on the stone-free rate (SFR) (p<0.01), whereas IW did not. An acute IPA (<30°) also had significant influence (p=0.01). The incidence of complications and OR-time were not influenced by the pelvicaliceal anatomy. fURS is a safe and efficient treatment option for lower pole kidney stones. A long infundibulum and a very acute IPA (<30°) negatively affect the SFR. However, with second look procedures, a complete stone clearance is achievable even in case of unfavorable anatomic conditions. A narrow infundibulum has no negative effect while using modern endoscopes. The complication rate is not affected by the collecting system's anatomy.

Artificial stone dust-induced functional and inflammatory abnormalities in exposed workers monitored quantitatively by biometrics.

PubMed

Ophir, Noa; Shai, Amir Bar; Alkalay, Yifat; Israeli, Shani; Korenstein, Rafi; Kramer, Mordechai R; Fireman, Elizabeth

2016-01-01

The manufacture of kitchen and bath countertops in Israel is based mainly on artificial stone that contains 93% silica as natural quartz, and ∼3500 workers are involved in cutting and processing it. Artificial stone produces high concentrations of silica dust. Exposure to crystalline silica may cause silicosis, an irreversible lung disease. Our aim was to screen exposed workers by quantitative biometric monitoring of functional and inflammatory parameters. 68 exposed artificial stone workers were compared to 48 nonexposed individuals (controls). Exposed workers filled in questionnaires, and all participants underwent pulmonary function tests and induced sputum analyses. Silica was quantitated by a Niton XL3 X-ray fluorescence spectrometer. Pulmonary function test results of exposed workers were significantly lower and induced sputa showed significantly higher neutrophilic inflammation compared to controls; both processes were slowed down by the use of protective measures in the workplace. Particle size distribution in induced sputum samples of exposed workers was similar to that of artificial stone dust, which contained aluminium, zirconium and titanium in addition to silica. In conclusion, the quantitation of biometric parameters is useful for monitoring workers exposed to artificial stone in order to avoid deterioration over time.

A new nomogram for prediction of outcome of pediatric shock-wave lithotripsy.

PubMed

Dogan, Hasan Serkan; Altan, Mesut; Citamak, Burak; Bozaci, Ali Cansu; Karabulut, Erdem; Tekgul, Serdar

2015-04-01

Despite the fact that shock-wave lithotripsy (SWL) remains a very good treatment option for smaller stones, it is being challenged by endourologic treatment modalities, which offer similar or even higher success rates in a shorter time, with minimal morbidity and invasiveness. The present study aimed to bring a new and practical insight in order to predict the outcomes of pediatric SWL and to provide objective information about pediatric SWL outcomes. To design a nomogram for predicting the outcomes of pediatric shock-wave lithotripsy. The study was conducted with a retrospective design and included 402 renal units who underwent SWL between January 2009 and August 2013. Patients with known cystine stone disease and cystinuria, with internal or external urinary diversion, were excluded. Analysis was performed on 383 renal units. Postoperative imaging was performed by plain abdominal graphy and ultrasonography with 3-month intervals. Patients who were completely free of stones were considered to be a success and statistical analysis was done regardingly Multivariate analysis was conducted by logistic regression analysis and a nomogram was developed. The male/female distribution was 216/167, with a mean age of 48 ± 40 months and a mean stone size of 9 ± 3.5 mm. The overall stone-free rate was 70% (270/383) and efficacy quotient was 0.57. Mean follow-up was 11 ± 11 months (3-54 months). The number of shock waves and amplitude of energy were higher in failed cases. Multivariate analysis showed that gender, stone size, number of stones, age, location of the stone, and history of previous intervention were found to be the independent prognostic factors for assessing the stone clearance rates. A nomogram was developed using these parameters. In this nomogram, the points achieved from each parameter are summed and total points correspond to the risk of failure in percent. A previous nomogram study by Onal et al. showed that younger age (<5 years), smaller stone burden (<1 cm), absence of previous stone treatment history, single stone, pelvis or upper ureter location (in girls) were favorable prognostic factors for successful outcome. As being the first pediatric study, it had some shortcomings. The study included 381 patients within a time period of 16 years. The present study included a similar number of cases within a 4-year period, which may reflect more homogeneity of data collection. Another issue is concern about the practical use of that nomogram. It constitutes two pages, which is a limiting factor for daily use. From a statistical point of view, they performed 200 bootstrapings with the aim of internal validation, which is less than the ideal number of 1000 bootstrapings, which was performed in the present nomogram. The presented nomogram is more practical, in that the pre-operative factors can be placed on the nomogram, the points can be added up and the parents can be given the approximate percentage of predicted stone-free rate after a single session. The expected treatment modality shown to the parents and patients ought to be the least minimally invasive, have the highest success rate, the least complication rate, and show the efficacy in one procedure at a time within the shortest period. However, SWL does not completely meet these criteria. The results gained from the present critical analysis of SWL in children, which was based on a strict definition of success, showed that outcome after a single session is not that good. Therefore, defining the patients who will benefit the most became one of the main issues. A more objective and skeptical look at SWL data enabled a nomogram to be developed that brings a new and practical insight in order to predict the outcomes of pediatric SWL. In most of the pediatric stone cases, SWL is the first-line treatment option. However, it is wise to define the patients who will benefit the most. Therefore, nomograms can be useful for this purpose. The nomogram in the present study revealed that gender, stone size, number of stones, age, location of the stone, and history of previous intervention were found to be the independent prognostic factors for assessing the stone clearance rates. This nomogram can practically be used to inform the parents, and for proper patient selection for SWL. Copyright © 2015 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

Sex differences in the stone tool-use behavior of a wild population of burmese long-tailed macaques (Macaca fascicularis aurea).

PubMed

Gumert, Michael D; Hoong, Low Kuan; Malaivijitnond, Suchinda

2011-12-01

We investigated sex differences in how Burmese long-tailed macaques (Macaca fascicularis aurea) used stone tools to open shelled food items along the shores of two islands in Laemson National Park, Thailand. Over a 2-week period in December 2009, we collected scan and focal samples on macaques when they were visible along the shores and mangroves. We found females used stones more often while feeding and used smaller tools than males. Females also processed sessile oysters more than males, whereas males processed unattached foods more than females. It was unclear which sex was overall more proficient at stone tool use, but males did perform significantly better at opening unattached food items with large pounding stones. Females also struck food items more times during tool-use bouts and at a faster rate, but no significant difference was found in average tool-use bout duration. Males processed foods slightly faster within a tool-use bout, but we were unable to detect a significant difference in the rate of food processing while foraging with tools. In summary females chipped open sessile oysters with an axing technique more than males, while males used larger stones to pound open unattached shelled food more often than females. Despite using pounding more than females, males also regularly utilized the axing technique on sessile oysters. Our results are the first assessment of sex differences in macaque stone tool use, providing a basis for comparison with tool use in other primates, and to nonfunctional forms of stone use in other macaques. © 2011 Wiley Periodicals, Inc.

A Dynamical Analysis of the Suitability of Prehistoric Spheroids from the Cave of Hearths as Thrown Projectiles

PubMed Central

Wilson, Andrew D.; Zhu, Qin; Barham, Lawrence; Stanistreet, Ian; Bingham, Geoffrey P.

2016-01-01

Spheroids are ball-shaped stone objects found in African archaeological sites dating from 1.8 million years ago (Early Stone Age) to at least 70,000 years ago (Middle Stone Age). Spheroids are either fabricated or naturally shaped stones selected and transported to places of use making them one of the longest-used technologies on record. Most hypotheses about their use suggest they were percussive tools for shaping or grinding other materials. However, their size and spherical shape make them potentially useful as projectile weapons, a property that, uniquely, humans have been specialised to exploit for millions of years. Here we show (using simulations of projectile motions resulting from human throwing) that 81% of a sample of spheroids from the late Acheulean (Bed 3) at the Cave of Hearths, South Africa afford being thrown so as to inflict worthwhile damage to a medium-sized animal over distances up to 25 m. Most of the objects have weights that produce optimal levels of damage from throwing, rather than simply being as heavy as possible (as would suit other functions). Our results show that these objects were eminently suitable for throwing, and demonstrate how empirical research on behavioural tasks can inform and constrain our theories about prehistoric artefacts. PMID:27506611

Laparoscopic transcystic management of choledocholithiasis.

PubMed

Hyser, M J; Chaudhry, V; Byrne, M P

1999-07-01

Our objective was to review our community hospital experience with laparoscopic management of choledocholithiasis from 1991 to 1997. We performed a retrospective review of all case records of patients with choledocholithiasis managed surgically at St. Francis Hospital during the study period. Data regarding the history, presentation, investigations, operative details, and follow-up were recorded. Procedures were performed by multiple attending surgeons supervising surgical residents. All common bile duct explorations (CBDEs) were performed by a transcystic approach and followed routine cholangiography. In most cases, cystic duct dilatation over a guide wire was followed by transcystic CBDE with choledochoscopy. Stone extraction was accomplished through a combination of flushing, basket manipulation, fragmentation, retrieval, or advancement of stones through the ampulla. Data were analyzed using SPSS computer software, and P < 0.05 was considered statistically significant. During the period of study there were 1053 laparoscopic cholecystectomies with and without cholangiography and 100 total CBDE performed. Of these, 54/100 had an attempt at laparoscopic CBDE. There were 39 females and 15 males, with a median age of 52 years (range 14-88). Presentation included acute cholecystitis or biliary colic (63%), gallstone pancreatitis (20%), and jaundice or cholangitis (17%). Successful laparoscopic stone removal was achieved in 36 of 54 (67%) cases. Eighteen of the remainder (33%) were converted to an open procedure. Size, number, position of stones, technical difficulties in accessing the common bile duct, and patient factors contributed to open conversion. The rate of successful laparoscopic CBDE improved for each individual surgeon from an average of 22 per cent in the first half of the study period (1991-1994) to 87 per cent in the second half (1995-1997). There was no operative mortality. Significant morbidity in the laparoscopic group included one retained stone and two cases of postoperative pancreatitis. There were three false negative preoperative endoscopic retrograde cholangiopancreatography examinations. Multivariate analysis showed that experience of the individual surgeon was the only significant factor predicting successful laparoscopic CBDE. Low initial success rate in the early phase of the study period improved dramatically to reach an overall success rate of 87 per cent in the second half. Laparoscopic management of common bile duct stones is possible in a community setting with a high success rate and minimal morbidity. It precludes excessive use of endoscopic retrograde cholangiopancreatography with its own set of complications but is associated with a significant learning curve. It is currently our preferred therapeutic approach for choledocholithiasis discovered pre- or intraoperatively.

Stone Soup: A Recipe for Building Resiliency Among Children

DTIC Science & Technology

2012-03-01

estimated to average 1 hour per response, including the time for reviewing instruction, searching existing data sources, gathering and maintaining the...the many hours I was away from home or busy writing, and for reminding me that it was time to do my homework when the kids sat down to do theirs...iron cauldron from his cloak, filled it with water , and began to build a fire under it. Then, with great ceremony, he drew an ordinary-looking stone

Upper Minnesota River Subbasins Study (Public Law 87-639) (Draft) Reconnaissance Stage Report (Plan of Study).

DTIC Science & Technology

1978-09-01

approximately 30 miles west of the Minnesota border, and flows southeast to Big Stone Lake. From Big Stone Lake the Minnesota River flows southeast to...storage is available in lakes and wetlands in the study area. Average annual runoff varies from 3 inches in the southeast to 1 inch in the northwest...UNCLASSIFIED NL E NI//////IE mIhNI-EIIIIIIE E-EIIIIIIIIIIu EIIIIIIIIIIIIu IIIIIIIIIIIIII II IEEIIEIh U. S. DEPARTMENT OF AGRICULTURE ga Il 0 YELLOW

SU-G-IeP2-15: Virtual Insertion of Digital Kidney Stones Into Dual-Source, Dual- Energy CT Projection Data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ferrero, A; Chen, B; Huang, A

Purpose: In order to investigate novel methods to more accurately estimate the mineral composition of kidney stones using dual energy CT, it is desirable to be able to combine digital stones of known composition with actual phantom and patient scan data. In this work, we developed and validated a method to insert digital kidney stones into projection data acquired on a dual-source, dual-energy CT system. Methods: Attenuation properties of stones of different mineral composition were computed using tabulated mass attenuation coefficients, the chemical formula for each stone type, and the effective beam energy at each evaluated tube potential. A previouslymore » developed method to insert lesions into x-ray CT projection data was extended to include simultaneous dual-energy CT projections acquired on a dual-source gantry (Siemens Somatom Flash). Digital stones were forward projected onto both detectors and the resulting projections added to the physically acquired sinogram data. To validate the accuracy of the technique, digital stones were inserted into different locations in the ACR CT accreditation phantom; low and high contrast resolution, CT number accuracy and noise properties were compared before and after stone insertion. The procedure was repeated for two dual-energy tube potential pairs in clinical use on the scanner, 80/Sn140 kV and 100/Sn140 kV, respectively. Results: The images reconstructed after the insertion of digital kidney stones were consistent with the images reconstructed from the scanner. The largest average CT number difference for the 4 insert in the CT number accuracy module of the phantom was 3 HU. Conclusion: A framework was developed and validated for the creation of digital kidney stones of known mineral composition, and their projection-domain insertion into commercial dual-source, dual-energy CT projection data. This will allow a systematic investigation of the impact of scan and reconstruction parameters on stone attenuation and dual-energy behavior under rigorously controlled conditions. Dr. McCollough receives research support from Siemens Healthcare.« less

Experience of a Tertiary-Level Urology Center in the Clinical Urological Events of Rare and Very Rare Incidence. VI. Unusual Events in Urolithiasis: 1. Long-Standing Urethral Stones without Underlying Anatomical Abnormalities in Male Children.

PubMed

Gadelkareem, Rabea A; Shahat, Ahmed A; Abdelhafez, Mohamed F; Moeen, Ahmed M; Ibrahim, Abdelrady S; Safwat, Ahmed S

2018-06-06

The study aimed to present our center's experience with long-standing urethral stones in male children with normal urethra. Retrospective search of our center data was done for the cases of long-standing urethral stones with normal urethra in male children during the period July 2001 - June 2016. Demographic and clinical data were studied. Of more than 54,000 urolithiasis procedures, 17 male children (0.031%) were operated for long-standing urethral stones with normal urethra. In 14 cases (82.4%), residence was rural and parental education levels were low or none. All children were regularly prompted voiding with a history of difficulty or dysuria. All the stones lodged in the posterior urethra with an approximate mean duration of 2 months. The mean stone size of 11.29 ± 3.88 mm and rough surfaces in 88.2% of cases represented the main predisposing factors. Major complications included rectal prolapse in 1 case and vesicoureteral reflux in 3 cases. Endoscopic push-back was followed by disintegration in 76.5% or cystolithotomy in 17.7%, while it failed in 1 case that was treated by cystolithotomy. Long-standing urethral stones in male children with normal urethra are very rare misdiagnoses. Stone topography and sociocultural factors predisposed to their lodgments and negligence. Endoscopic treatment is the best approach. © 2018 S. Karger AG, Basel.

Advanced non-contrasted computed tomography post-processing by CT-Calculometry (CT-CM) outperforms established predictors for the outcome of shock wave lithotripsy.

PubMed

Langenauer, J; Betschart, P; Hechelhammer, L; Güsewell, S; Schmid, H P; Engeler, D S; Abt, D; Zumstein, V

2018-05-29

To evaluate the predictive value of advanced non-contrasted computed tomography (NCCT) post-processing using novel CT-calculometry (CT-CM) parameters compared to established predictors of success of shock wave lithotripsy (SWL) for urinary calculi. NCCT post-processing was retrospectively performed in 312 patients suffering from upper tract urinary calculi who were treated by SWL. Established predictors such as skin to stone distance, body mass index, stone diameter or mean stone attenuation values were assessed. Precise stone size and shape metrics, 3-D greyscale measurements and homogeneity parameters such as skewness and kurtosis, were analysed using CT-CM. Predictive values for SWL outcome were analysed using logistic regression and receiver operating characteristics (ROC) statistics. Overall success rate (stone disintegration and no re-intervention needed) of SWL was 59% (184 patients). CT-CM metrics mainly outperformed established predictors. According to ROC analyses, stone volume and surface area performed better than established stone diameter, mean 3D attenuation value was a stronger predictor than established mean attenuation value, and parameters skewness and kurtosis performed better than recently emerged variation coefficient of stone density. Moreover, prediction of SWL outcome with 80% probability to be correct would be possible in a clearly higher number of patients (up to fivefold) using CT-CM-derived parameters. Advanced NCCT post-processing by CT-CM provides novel parameters that seem to outperform established predictors of SWL response. Implementation of these parameters into clinical routine might reduce SWL failure rates.

COMPARISON BETWEEN EXTRACORPOREAL SHOCK WAVE LITHOTRIPSY AT 120 AND 60 SHOCKWAVES PER MINUTE FOR TREATMENT OF URINARY STONES.

PubMed

Kashima, Soki; Horikawa, Yohei; Obara, Takashi; Muto, Yumina; Koizumi, Atsushi; Honma, Naoko; Akihama, Susumu; Shimoda, Naotake

2016-01-01

(Purpose) It has recently been suggested that a slow delivery rate of shockwaves by extracorporeal shock wave lithotripsy (SWL) improved treatment outcomes for urinary stones. We retrospectively analyzed the treatment outcomes of different shockwave delivery rates at 120 and 60 shockwaves per minute. (Patients and method) A total of 88 patients were treated at a fast delivery rate of 120 shockwaves per minute between July 2010 and April 2012, and 139 patients were treated at a slow delivery rate of 60 shockwaves per minute between May 2012 and May 2014 (n=227) using a Sonolith ® Praktis lithotripter. The treatment outcome of stone-free rate (SFR) after one SWL session was assessed at four weeks. (Result) SWL at 60 shockwaves per minute resulted in a significantly higher SFR compared with SWL at 120 shockwaves per minute (39.8% and 59.0%, respectively, p=0.0047), particularly for upper ureter (U1) stones (53.1% and 72.0%, respectively, p=0.028). Multivariate analysis showed that younger age, stone sizes of 10 mm or less, U1 stones, and slow delivery rate were significant predictors of a stone-free outcome. There were fewer adverse events after the delivery rate of 60 shockwaves per minute (p=0.058). (Conclusion) Our study suggests that SWL at 60 shockwaves per minute should be recommended to successfully treat urinary stones using the Sonolith ® Praktis lithotripter.

Obesometric factors associated with increased skin-to-stone distances in renal stone patients.

PubMed

Allard, Christopher B; Shuster, Anatoly; Pinthus, Jehonathan H; Farrokhyar, Forough; Raees, A; Patlas, Michael; Matsumoto, Edward D; Whelan, J Paul

2012-12-01

Obese patients are at increased risk for renal stones as well as treatment failures due to increased skin-to-stone distances (SSD) and harder stone compositions. We investigated the relationships between obesometric parameters (body mass index [BMI], body fat distribution and obesity-related hormone levels) with SSD and stone hardness. We prospectively enrolled patients undergoing stone interventions at our institution. Computed tomography (CT) scans were analyzed; adipose tissue was identified according to Hounsfield units (HU) and separated into subcutaneous (SAT) and visceral (VAT) components. The pixels were averaged at three levels to calculate fat distribution: %VAT = (VAT)/(VAT + SAT). SSD was measured and HU were used as a surrogate for stone hardness. Obesity-related hormones leptin and adiponectin were measured by ELISA. Seventy-nine patients were prospectively enrolled. Mean BMI and %VAT were 30.02 kg/m2 and 40.13 kg/m2. Mean leptin and adiponectin levels were 17.5 ng/mL and 7.67 mcg/mL indicating high risk for metabolic consequences of obesity. Females had greater proportions of subcutaneous fat than males (%VAT 28.4 versus 46.94, p < 0.001) and greater SSD (11.26 cm versus 9.86 cm, p = 0.025). Among obese patients, subcutaneous fat correlated with SSD independently of BMI (r = 0.454, p = 0.008). Obese patients with %VAT > 40 versus < 40 had SSD of 11.35 cm versus 13.7 cm (p = 0.005). Diabetics had harder stone compositions as measured by HU than non-diabetics (982.86 versus 648.86, p = 0.001). Obesometric parameters such as BMI, body fat distribution, and the presence of diabetes mellitus are important considerations in the management of renal stone disease. A large proportion of subcutaneous fat, which can be estimated by physical examination, predicts SSD among obese patients and may aid treatment decisions in patients, particularly those without pre-treatment CT scans. Further studies are needed to refine the role of obesometrics in personalizing treatment decisions.

Comparison of extracorporeal shock wave lithotripsy for inferior caliceal calculus between children and adults: a retrospective analysis--why do results vary?

PubMed

Mandal, Swarnendu; Sankhwar, Satya N; Singh, Manish Kumar; Kathpalia, Rohit; Singh, Vishwajeet; Goel, Apul; Singh, Bhupendra P; Dalela, Divakar

2012-12-01

To retrospectively evaluate the effectiveness of extracorporeal shock wave lithotripsy (ESWL) for inferior caliceal calculi ≤ 20 mm in size and compare the results between children and adults. From January 2004 to January 2012, ESWL was performed for inferior caliceal calculi in 230 children and 1006 adults. The Dornier compact alpha-K1025163 (Dornier Med Tech) was used. The success rates, number of ESWL sessions required, and auxiliary procedures used were evaluated in a comparative manner. The overall stone-free rate (for both stone sizes) was 82.2% for children and 40% for the adults. Of the children, 17% had a residual stone compared with 47.8% of the adults. ESWL was unsuccessful in 0.8% of children and 12.2% of adults. The mean number of ESWL sessions required in children and adults was 1.43 (range 1-4) and 2.13 (range 1-4), respectively. Repeat treatment was required in 31% of the children and 65% of the adults. Auxiliary procedures were required in 5.2% of the children and 16.2% of the adults. Complications were seen in 5.6% of the children and 15% of the adults. The results of ESWL for inferior caliceal calculi ≤ 20 mm in adults remains poor but not so in children. Children can achieve high stone-free rates, require a fewer number of ESWL sessions than adults to be stone free, and have a lower need for repeat treatment and auxiliary procedures, and have fewer complications. Copyright © 2012 Elsevier Inc. All rights reserved.

Stone volume is best predictor of operative time required in retrograde intrarenal surgery for renal calculi: implications for surgical planning and quality improvement.

PubMed

Sorokin, Igor; Cardona-Grau, Diana K; Rehfuss, Alexandra; Birney, Alan; Stavrakis, Costas; Leinwand, Gabriel; Herr, Allen; Feustel, Paul J; White, Mark D

2016-11-01

Retrograde intrarenal surgery (RIRS) is highly successful at eliminating renal stones of various sizes and compositions. As urologists are taking on more complex procedures using RIRS, this has led to an increase in operative (OR) times. Our objective was to determine the best predictor of OR time in patients undergoing RIRS. We retrospectively reviewed the records of patients undergoing unilateral RIRS for solitary stones over a 10 year time span. Stones were fragmented and actively extracted using a basket. Variables potentially affecting OR time such as patient age, sex, BMI, lower pole stone location, volume, Hounsfield units (HU), composition, ureteral access sheath (UAS) use, and pre-operative stenting were collected. Multivariable linear and stepwise regression was used to evaluate the predictors of OR time. There were 118 patients that met inclusion criteria. The median stone volume was 282.6 mm 3 (IQR 150.7-644.7) and the mean OR time was 50 min (±25.9 SD). On univariate linear regression, stone volume had a moderate correlation with OR time (y = 0.022x + 38.2, r 2  = 0.363, p < 0.01). On multivariable stepwise regression, stone volume had the strongest impact on OR time, increasing time by 2.0 min for each 100 mm 3 increase in stone volume (p < 0.001). UAS added 13.5 (SE 3.9, p = 0.001) minutes and renal lower pole location added 9 min (SE 4.3, p = 0.03) in each case they were used. Pre-operative stenting, HU, calcium oxalate stone composition, sex, and age had no significant effect on OR time. Amongst the main stone factors in RIRS, stone volume has the strongest impact on operative time. This can be used to predict the length of the procedure by roughly adding 2 min per 100 mm 3 increase in stone volume.

The current role of percutaneous chemolysis in the management of urolithiasis: review and results.

PubMed

Kachrilas, Stefanos; Papatsoris, Athanasios; Bach, Christian; Bourdoumis, Andreas; Zaman, Faruquz; Masood, Junaid; Buchholz, Noor

2013-08-01

The treatment of urolithiasis has changed dramatically over the past several decades. Novel technologies have led to new management protocols. Percutaneous chemolysis as a primary or adjuvant treatment for urinary tract stones has widely been neglected. We present our own experience with it and discuss it in the light of an extensive literature review. From a MEDLINE search on percutaneous chemolysis we evaluated the most important studies, a total of 58 articles, 43 case series and 15 review articles. In our unit between 2001 and 2011, 29 patients (mean age 62 years) with infectious staghorn calculi were treated with adjuvant percutaneous chemolysis post-percutaneous nephrolithotripsy. There were 17 women, with 10 complete and 14 partial staghorn stones (mean size 32 mm). Patients were generally deemed at high risk to undergo another procedure in the future. Suby G solution was used following an established protocol. Sixteen patients (55.1 %) were stone free after chemolysis, eight stones showed partial dissolution, half of them with so-called "insignificant" residual fragments <4 mm. Patients with residual stones underwent SWL. Mean follow-up was 5.25 years (1-11). One stone-free patient (6 %) and three of eight patients (37.5 %) with residual fragments post local chemolysis, developed new stones during follow-up. The often neglected percutaneous chemolysis represents a significant and effective.

Cumulative sum analysis for experiences of a single-session retrograde intrarenal stone surgery and analysis of predictors for stone-free status.

PubMed

Cho, Sung Yong; Choo, Min Soo; Jung, Jae Hyun; Jeong, Chang Wook; Oh, Sohee; Lee, Seung Bae; Son, Hwancheol; Jeong, Hyeon

2014-01-01

This study investigated the learning curve of a single-session retrograde intrarenal surgery (RIRS) in patients with mid-sized stones. Competence and trainee proficiency for RIRS was assessed using cumulative sum analysis (CUSUM). The study design and the use of patients' information stored in the hospital database were approved by the Institutional Review Board of our institution. A retrospective review was performed for 100 patients who underwent a single-session RIRS. Patients were included if the main stone had a maximal diameter between 10 and 30 mm. The presence of a residual stone was checked on postoperative day 1 and at one-month follow-up visit. Fragmentation efficacy was calculated "removed stone volume (mm(3)) divided by operative time (min)". CUSUM analysis was used for monitoring change in fragmentation efficacy, and we tested whether or not acceptable surgical outcomes were achieved. The mean age was 54.7±14.8 years. Serum creatinine level did not change significantly. Estimated GFR and hemoglobin were within normal limits postoperatively. The CUSUM curve tended to be flat until the 25th case and showed a rising pattern but declined again until the 56th case. After that point, the fragmentation efficacy reached a plateau. The acceptable level of fragmentation efficacy was 25 ml/min. Multivariate logistic regression analyses showed that stone-free rate was significantly lower for cases with multiple stones than those with a single stone (OR = 0.147, CI 0.032 - 0.674, P value  = 0.005) and for cases with higher number of sites (OR = 0.676, CI 0.517 - 0.882, P value  = 0.004). The statistical analysis of RIRS learning experience revealed that 56 cases were required for reaching a plateau in the learning curve. The number of stones and the number of sites were significant predictors for stone-free status.

Laparoscopy assisted percutaneous stone surgery can be performed in multiple ways for pelvic ectopic kidneys.

PubMed

Soylemez, Haluk; Penbegül, Necmettin; Utangac, Mehmet Mazhar; Dede, Onur; Çakmakçı, Süleyman; Hatipoglu, Namık Kemal

2016-08-01

Pelvic kidney stones remain a unique challenge to the endourologists. Treatment options include open surgery, extracorporeal shockwave lithotripsy, percutaneous nephrolithotomy (PNL), retrograde intrarenal surgery, and laparoscopy assisted PNL (LA-PNL). As a minimal invasive option, LA-PNL can decrease the risk for bowel and major vessel injury. Here, we describe our experience using the LA-PNL procedures with different combinations, to treat kidney stones in multiple patients with a pelvic ectopic kidney (PEK). Eight patients, with PEK, kidney stones, and no other treatment choice, but open surgery, were included in the study. Two different laparoscopic techniques such as mesocolon dissection and transmesocolic, and four different percutaneous procedures such as standard-PNL, mini-PNL, micro-PNL, and a PNL through the renal pelvis were used for stone extraction in these patients. The mean age of patients was 25.6 ± 12.9 years and mean stone size was 524.1 ± 430.3 mm(2). Mean operation time was 150.5 ± 40.0 (77-210) min which was composed of retrograde catheterization (14.8 ± 2.9 min), laparoscopic procedure (48.7 ± 20.6 min) and PNL procedure (86.8 ± 31.1 min). Residual stones were seen in two patients (no additional treatment was need), while a 'stone-free' procedure was achieved in six patients (75.0 %). On the post-operative first month visit, a stone was observed on radiological examinations in only one patient (87.5 % stone-free). Mean hospitalization time was 2.8 ± 0.9 days. No perioperative or post-operative complication was observed in all patients. LA-PNL surgery is a safe and effective option for treatment of PEK stones, and has several alternative approaches.

Size-dependent cellular uptake mechanism and cytotoxicity toward calcium oxalate on Vero cells

NASA Astrophysics Data System (ADS)

Sun, Xin-Yuan; Gan, Qiong-Zhi; Ouyang, Jian-Ming

2017-02-01

Urinary crystals with various sizes are present in healthy individuals and patients with kidney stone; however, the cellular uptake mechanism of calcium oxalate of various sizes has not been elucidated. This study aims to compare the internalization of nano-/micron-sized (50 nm, 100 nm, and 1 μm) calcium oxalate monohydrate (COM) and dihydrate (COD) crystals in African green monkey renal epithelial (Vero) cells. The internalization and adhesion of COM and COD crystals to Vero cells were enhanced with decreasing crystal size. Cell death rate was positively related to the amount of adhered and internalized crystals and exhibited higher correlation with internalization than that with adhesion. Vero cells mainly internalized nano-sized COM and COD crystals through clathrin-mediated pathways as well as micron-sized crystals through macropinocytosis. The internalized COM and COD crystals were distributed in the lysosomes and destroyed lysosomal integrity to some extent. The results of this study indicated that the size of crystal affected cellular uptake mechanism, and may provide an enlightenment for finding potential inhibitors of crystal uptake, thereby decreasing cell injury and the occurrence of kidney stones.

Medical expulsive treatment in pediatric urolithiasis.

PubMed

Atan, Ali; Balcı, Melih

2015-03-01

The frequency of stone disease in childhood ranges between 0.1-5 percent. Stone disease occurs as a result of enviromental, metabolic, anatomical, infectious and nutritional factors. Percutaneous nephrolitotomy, uretherorenoscopy, laparoscopic surgery, open surgery and extracorporeal shock wave lithothripsy are treatment alternatives for stone disease during childhood. However, these methods are not completely innocent. Some complications may occur after these procedures. These procedures are generally not cost- effective. Even invasive procedures have high success rates, so medical expulsive treatment modalities have become an alternative for a group of patients. Nonsteroidal anti- inflammatory drugs, antimuscarinic drugs, phospodiesterase type 5 inhibitors, steroids, calcium channel blockers and alpha blockers are treatment alterneatives used for this modality in the literature. The drug is chosen according to the location, size, and composition of the stone, recent technology, cost, surgeon's experience and surgeon's and the parents' preferences. In this review article the following topics will be discussed such as "Why medical expulsive treatment is needed during childhood? Which drug should be chosen for which stone type? How long should a treatment of urolithiasis last?

Direct pelvic access percutaneous nephrolithotomy in management of ectopic kidney stone: a case report and literature review.

PubMed

Mehmet, Rifaioglu Murat; Rustu, Yalcinkaya Fatih; Hanefi, Bayarogullari; Mursel, Davarci; Fusun, Aydogan; Mehmet, Inci

2013-01-01

Percutaneous nephrolithotomy (PNL) is an effective procedure for the treatment of patients with large or complex stones. PNL is challenging in anomalous kidneys, certain patients, such as those with renal ectopia. It is unable to undergo PNL in conventional technique safely in these cases. We presented a case report of laparoscopic-assisted PNL via direct pelvic puncture in a pelvic kidney stone and discussed previous published literature. A 49-year-old man presented with right lower quadrant pain and hematuria. Intravenous pyelography and three-dimensional computerized tomography revealed an opaque 2.7 × 1.7 cm pelvis renalis stone in a right side ectopic pelvic kidney with grade III hydronephrosis. Laparoscopic-assisted tubeless PNL was performed to remove the calculus. Laparoscopic-assisted PNL as a minimally invasive therapy in ectopic kidney has many advantages. Our case showed that, in pelvic ectopic kidney with pelvic stones greater than 1.5 cm in size, laparoscopic-assisted PNL via direct pelvis puncture is a safe and effective technique.

Determination of ureter stent appearance on dual-energy computed tomography scan.

PubMed

Jepperson, Maria A; Thiel, David D; Cernigliaro, Joesph G; Broderick, Gregory A; Parker, Alexander S; Haley, William E

2012-11-01

To examine the dual-energy computed tomography (DECT) properties of 7 commonly used ureteral stents to optimize stent selection for calculi monitored using DECT. The use of DECT to evaluate renal and ureteral calculi has recently increased. Seven stents were individually placed in a fish bowl phantom and imaged using a Siemens Somatom Definition Flash CT scanner. DECT peak tube potentials of 80 and 140 kVp and 100 and 140 kVp were used, reflecting our current dual-energy protocols. These were compared to 31 in vivo stents of known composition. The data were reconstructed on a multimodality WorkPlace (Siemens) using CT syngo Post-Processing Suite software. The average patient age was 64 years (range 27-90). The average body mass index was 31.9 kg/m(2) (range 24-51.6). Of the 27 patients, 4 had uric acid stones and 22 had calcium-based stones; 1 patient had undergone renal transplantation. No difference was seen in the dual-energy characterization of stents from the same manufacturer. All imaged Cook and Bard stents had a dual-energy characterization that approached that of calcium stones (blue). All Boston Scientific and Gyrus ACMI stents had a dual-energy characterization resembling that of uric acid stones (red). The present study evaluated the stent appearance on DECT for various stent manufacturers. This information will aid in the optimal stent selection for patients undergoing treatment of renal calculi and followed up with DECT. Copyright © 2012 Elsevier Inc. All rights reserved.

Citrate salts for preventing and treating calcium containing kidney stones in adults.

PubMed

Phillips, Rebecca; Hanchanale, Vishwanath S; Myatt, Andy; Somani, Bhaskar; Nabi, Ghulam; Biyani, C Shekhar

2015-10-06

Kidney stones affect people worldwide and have a high rate of recurrence even with treatment. Recurrences are particularly prevalent in people with low urinary citrate levels. These people have a higher incidence of calcium phosphate and calcium oxalate stones. Oral citrate therapy increases the urinary citrate levels, which in turn binds with calcium and inhibits the crystallisation thus reduces stone formation. Despite the widespread use of oral citrate therapy for prevention and treatment of calcium oxalate stones, the evidence to support its clinical efficacy remains uncertain. The objective of this review was to determine the efficacy and adverse events associated with citrate salts for the treatment and prevention of calcium containing kidney stones. We searched the Cochrane Kidney and Transplant Specialised Register to 29 July 2015 through contact with the Trials' Search Co-ordinator using search terms relevant to this review. We included randomised controlled trials (RCTs) that assessed the efficacy and adverse events associated with citrate salts for the treatment and prevention of calcium containing kidney stones in adults treated for a minimum of six months. Two authors assessed studies for inclusion in this review. Data were extracted according to predetermined criteria. Summary estimates of effect were obtained using a random-effects model, and results were expressed as risk ratios (RR) and their 95% confidence intervals (CI) for dichotomous outcomes, and mean difference (MD) and 95% CI for continuous outcomes. We included seven studies that included a total of 477 participants, most of whom had oxalate stones. Of these, three studies (247 participants) compared potassium citrate with placebo or no intervention; three (166 participants) compared potassium-sodium citrate with no intervention; and one (64 participants) compared potassium-magnesium citrate with placebo. Overall, quality of the reporting of the included studies was considered moderate to poor, and there was a high risk of attrition bias in two studies.Compared with placebo or no intervention, citrate therapy significantly reduced the stone size (4 studies, 160 participants: RR 2.35, 95% CI 1.36 to 4.05). New stone formation was significantly lower with citrate therapy compared to control (7 studies, 324 participants: RR 0.26, 95% CI 0.10 to 0.68). The beneficial effect on stone size stability was also evident (4 studies, 160 participants: RR 1.97, 95% CI 1.19 to 3.26). Adverse events were reported in four studies, with the main side effects being upper gastrointestinal disturbance and one patient reported a rash. There were more gastrointestinal adverse events in the citrate group; however this was not significant (4 studies, 271 participants: RR 2.55, 95% CI 0.71 to 9.16). There were significantly more dropouts due to adverse events with citrate therapy compared to control (4 studies, 271 participants: RR 4.45, 95% CI 1.28 to 15.50). The need for retreatment was significantly less with citrate therapy compared to control (2 studies, 157 participants: RR 0.22, 95% CI 0.06 to 0.89). Citrate salts prevent new stone formation and reduce further stone growth in patients with residual stones that predominantly contain oxalate. The quality of reported literature remains moderate to poor; hence a well-designed statistically powered multi-centre RCT is needed in order to answer relevant questions concerning the efficacy of citrate salts.

Incidental renal stones in potential live kidney donors: prevalence, assessment and donation, including role of ex vivo ureteroscopy.

PubMed

Olsburgh, Jonathon; Thomas, Kay; Wong, Kathie; Bultitude, Matthew; Glass, Jonathan; Rottenberg, Giles; Silas, Lisa; Hilton, Rachel; Koffman, Geoff

2013-05-01

WHAT'S KNOWN ON THE SUBJECT? AND WHAT DOES THE STUDY ADD?: Previously, donors with asymptomatic stones found incidentally on CT were not considered ideal donor candidates because of the presumed risk of morbidity to both the donor and recipient. Increasingly, studies show that these risks are low. This study aims to evaluate the long-term safety of using ex vivo ureteroscopy to remove the stones from the donor kidney on the bench before donation. Outcomes so far suggest that this technique can safely render a kidney stone-free before transplantation. This has led to 20 more transplants in our institution than would otherwise be possible. To evaluate the prevalence of asymptomatic renal stones in our potential donor population. To assess the safety and success of ex vivo ureteroscopy (ExURS) to remove stones from explanted donor kidneys before transplantation. We conducted a retrospective analysis of 377 computed tomography (CT) angiograms of potential kidney donors between October 2004 and May 2007 to assess the prevalence of asymptomatic renal stones in our donor population. Between October 2005 and October 2011, kidneys from suitable donors underwent ExURS. Stones were removed using basket extraction or were fragmented with holmium laser on bench before transplantation. Immediate and long-term complications of the transplanted recipients were recorded. Donors were followed with yearly ultrasonography of the remaining kidney in addition to standard follow-up protocol. Review of 377 CT angiograms between October 2004 to May 2007 showed a 5% prevalence of asymptomatic renal stones. Out of 55 potential donors (19 identified between October 2004 to May 2007 and a further 36 identified since May 2007), 20 donors with stones proceeded to donation, with stone size ranging from 2 to 12 mm. Of the patients, 17 proceeded to ExURS. Stones were removed in 10 patients; five with basket retrieval, four with laser fragmentation and one with both laser fragmentation and basket retrieval. There were no early or late allograft stone-related complications and no evidence of stones on follow-up imaging at a mean (range) of 10 (1-24) months. There has been no reported stone recurrence in any of the donors to date and no stone on ultrasonography of eight donors with >1-year follow-up (mean 26 months, range 12-49 months). Asymptomatic renal stones are present in 5% of our donors. ExURS can be safely used to remove stones in these kidneys before transplantation, without the risk of subjecting the donor to an additional stone-removing procedure. Continued long-term follow-up of donors and recipients is still required to ensure the safety of this approach. © 2012 The Authors. BJU International © 2012 BJU International.

Efficacy of endoscopic combined intrarenal surgery in the prone split-leg position for staghorn calculi.

PubMed

Hamamoto, Shuzo; Yasui, Takahiro; Okada, Atsushi; Koiwa, Satoshi; Taguchi, Kazumi; Itoh, Yasunori; Kawai, Noriyasu; Hashimoto, Yoshihiro; Tozawa, Keiichi; Kohri, Kenjiro

2015-01-01

Abstract Purpose: To evaluate the efficacy of endoscopic combined intrarenal surgery (ECIRS) using retrograde flexible ureteroscopy and miniature percutaneous nephrolithotomy (PNL) for the treatment of patients with staghorn calculi in the prone split-leg position. We retrospectively reviewed the records of 42 patients with staghorn calculi (45.8±3.2 mm) who underwent ECIRS using retrograde flexible ureteroscopy and miniature PNL in the prone split-leg position for the treatment of staghorn calculi in our center between December 2010 and August 2013. A flexible ureteroscope with a laser fiber was inserted through a ureteral access sheath, and lithoclast lithotripsy was performed through a mini-percutaneous tract. Both procedures were performed simultaneously by two urologists. Surgical parameters, including surgical time, stone-free (SF) rates, modified Clavien complication grades, and risk factors for residual stones, were analyzed. Fifteen patients (35.7%) had complete staghorn calculi. Among the 42 staghorn calculi treated, 23 had 0 to 5 stone branches, 14 had 6 to 10 stone branches, and 5 had ≥11 stone branches. All procedures were performed successfully using a single lithotripsy tract with the patient in the prone split-leg position. The mean surgical time was 143.2±9.2 minutes. The initial SF rate was 71.4%, and the final SF rate was 83.3% after further treatment. One patient required a blood transfusion (2.4%), but no patient experienced a ≥3 Clavien grade complication. Risk factors for residual stones were stone size, stone surface area, complete staghorn calculi, and the number of stone branches. ECIRS for staghorn calculi in the prone split-leg position is a safe, efficient, and versatile method for the effective management of staghorn calculi without the creation of multiple percutaneous tracts.

Clinical value of crystalluria and quantitative morphoconstitutional analysis of urinary calculi.

PubMed

Frochot, Vincent; Daudon, Michel

2016-12-01

Crystalluria is a marker of urine supersaturation with substances deriving from metabolic disorders, inherited diseases or drugs. The investigation of crystalluria must be done according to a protocol which includes the delivery to the laboratory of a proper urine sample, the use of a microscope equipped with polarized light, the accurate knowledge of urine pH, and a comprehensive examination of the crystals, which is based on their identification, quantification and size measurement. For unusual crystals, infrared spectroscopy may also be needed. If the formation of stones is always preceded by crystalluria, the reverse is not true. In addition to the crystalline composition, stone morphology provides valuable information on stone activity and, for some crystalline species, major information regarding the underlying pathology. Fourier transform infrared spectroscopy (FTIR) reliably identify specific forms of nephrolithiasis, as common-type stones made of calcium oxalate (CaOx) and/or calcium phosphate that is combined with morphology classification; using this method, stones may be classified into 6 types subdivided in 22 subtypes. The investigation of crystalluria is an inexpensive and valuable tool for the detection and the monitoring of inherited and acquired diseases associated with urinary stone formation or acute or chronic renal function impairment from intrarenal crystal precipitation. Selective FTIR identification of the composition of core (or the umbilication), middle part, and surface of every stone allows identification of the initiating lithogenic process (in the nucleus or in the Randall's plaque) and the factors which subsequently contributed to stone growth. In conclusion, the proposed morpho-constitutional method of urinary stone analysis, which moreover is rapid and low cost, provides clinically relevant orientations for targeted etiologic evaluation. Copyright © 2016 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.

Role of combined use of potassium citrate and tamsulosin in the management of uric acid distal ureteral calculi.

PubMed

El-Gamal, Osama; El-Bendary, Mohamed; Ragab, Maged; Rasheed, Mohamed

2012-06-01

In this article, we investigated the effect of the combined use of tamsulosin and potassium citrate (Uralyt-U(®)) for the treatment of uric acid stones in the distal ureter. The study was designed as a prospective, double blind randomized controlled trial. A total of 191 adult patients with radiolucent distal ureteral calculi were recruited. We included patients with solitary stones ≥5 mm with mild or moderate hydronephrosis and a normal contralateral tract. The patients were randomized into four equal groups (the placebo, tamsulosin, Uralyt-U(®), and the combined treatment groups). The patients were treated for a maximum duration of 4 weeks or until stone expulsion. The stone size in all groups ranged from 5 to 11 mm (7.69 ± 1.7 mm). The total expulsion rate of the stones was significantly lower in the control group (26.1%) compared with that of any of the other three groups (68.8, 58.7, and 84.8% respectively) (P < 0.05). Meanwhile, the difference between the Uralyt-U(®) group and the combined treatment group was also statistically significant (P < 0.05). When we studied the patients with stones >8 mm as a separate subgroup to find the effect of the used drugs on the relatively large stones, we detected that the expulsion rate of these stones was significantly higher in the patients who received the combined treatment in comparison with any of the other three groups (P < 0.05). In conclusion, the use of urinary alkalization with tamsulosin can increase the frequency of spontaneous passage of distal ureteral uric acid stones especially those of 8-11 mm.

Decreased Radiation Exposure and Increased Efficacy in Extracorporeal Lithotripsy Using a New Ultrasound Stone Locking System.

PubMed

Abid, Nadia; Ravier, Emmanuel; Promeyrat, Xavier; Codas, Ricardo; Fehri, Hakim Fassi; Crouzet, Sebastien; Martin, Xavier

2015-11-01

To compare fluoroscopy duration, radiation dose, and efficacy of two ultrasound stone localization systems during extracorporeal shockwave lithotripsy (SWL) treatment. Monocentric prospective data were obtained from patients consecutively treated for renal stones using the Sonolith(®) i-sys (EDAP TMS) lithotripter, with fluoroscopy combined with ultrasound localization using an "outline" Automatic Ultrasound Positioning Support (AUPS) (group A), or the "free-line" Visio-Track (VT) (EDAP-TMS) hand-held three-dimensional ultrasound stone locking system (group B). Efficacy rate was defined as the within-groups proportion stone free or with partial stone fragmentation not needing additional procedures. Statistical analysis used Pearson chi-square tests for categoric variables, nonparametric Mann-Whitney tests for continuous variables, and linear regression for operator learning curve with VT. Continuous variables were reported as median (range) values. Patients in group A (n=73) and group B (n=81) were comparable in baseline characteristics (age, kidney stone size, others) and in SWL application (duration, number of shocks, energy [Joules]). During SWL, the median (range) duration (seconds) of radiation exposure was 159.5 (0-690) in group A and 3.5 (0-478) in group B (P<0.001) and irradiation dose (mGy.cm(2)), 10598 (0-54843) in group A and 163 (0-13926) in group B (P<0.001). Fluoroscopy time significantly decreased with operator experience using VT. The efficacy rate was 54.5% in group A and 79.5% in group B (P=0.001). VT significantly reduced fluoroscopy use during SWL and the duration and dose of patient exposure to ionizing radiation. Stone treatment efficacy was significantly greater with VT mainly because of a better real-time monitoring of the stone.

Outcome of a session of extracorporeal shock wave lithotripsy before endoscopic retrograde cholangiopancreatography for problematic and large common bile duct stones

PubMed Central

Tao, Tao; Zhang, Ming; Zhang, Qi-Jie; Li, Liang; Li, Tao; Zhu, Xiao; Li, Ming-Dong; Li, Gui-Hua; Sun, Shu-Xia

2017-01-01

AIM To compare the efficacy of a session of extracorporeal shock wave lithotripsy (ESWL) before endoscopic retrograde cholangiopancreatography (ERCP) vs ERCP only for problematic and large common bile duct (CBD) stones. METHODS Adult patients with CBD stones for whom initial ERCP was unsuccessful because of the large size of CBD stones were identified. The patients were randomized into two groups, an “ESWL + ERCP group” and an “ERCP-only” group. For ESWL + ERCP cases, ESWL was performed prior to ERCP. Clearance of the CBD, complications related to the ESWL/ERCP procedure, frequency of mechanical lithotripsy use and duration of the ERCP procedure were evaluated in both groups. RESULTS There was no significant difference in baseline characteristics between the two groups. A session of ESWL before ERCP compared with ERCP only resulted in similar outcomes in terms of successful stone removal within the first treatment session (74.2% vs 71.0%, P = 0.135), but a higher clearance rate within the second treatment session (84.4% vs 51.6%, P = 0.018) and total stone clearance (96.0% vs 86.0%, P = 0.029). Moreover, ESWL prior to ERCP not only reduced ERCP procedure time (43 ± 21 min vs 59 ± 28 min, P = 0.034) and the rate of mechanical lithotripsy use (20% vs 30%, P = 0.025), but also raised the clearance rate of extremely large stones (80.0% vs 40.0%, P = 0.016). Post-ERCP complications were similar for the two groups. CONCLUSION Based on the higher rate of successful stone removal and minimal complications, ESWL prior to ERCP appears to be a safe and effective treatment for the endoscopic removal of problematic and large CBD stones. PMID:28785149

Efficacy and safety of tamsulosin as a medical expulsive therapy for stones in children.

PubMed

Aldaqadossi, Hussein A; Shaker, Hossam; Saifelnasr, Mohammed; Gaber, Mohammed

2015-06-01

To evaluate the efficacy of tamsulosin for promoting ureteric stone expulsion in children, based on the confirmed efficacy of tamsulosin as a medical expulsive therapy in adults. From February 2010 to July 2013, 67 children presenting with a distal ureteric stone of <1 cm as assessed on unenhanced computed tomography were included in the study. The patients were randomised into two groups, with group 1 (33 patients) receiving tamsulosin 0.4 mg and ibuprofen, and group 2 (34) receiving ibuprofen only. They were followed up for 4 weeks. Endoscopic intervention was indicated for patients with uncontrolled pain, recurrent urinary tract infection, hypersensitivity to tamsulosin and failure of stone passage after 4 weeks of conservative treatment. Sixty-three patients completed the study. There were no statistically significant differences between the groups in patient age, body weight and stone size, the mean (SD) of which was 6.52 (1.8) mm in group 1 vs. 6.47 (1.79) mm in group 2 (P = 0.9). The mean (SD) time to stone expulsion in group 1 was 7.7 (1.9) days, vs. 18 (1.73) days in group 2 (P < 0.001). The analgesic requirement (mean number of ketorolac injections) in group 1 was significantly less than in group 2, at 0.55 (0.8) vs. 1.8 (1.6) (P < 0.001). The stone-free rate was 87% in group 1 and 63% in group 2 (P = 0.025). Tamsulosin used as a medical expulsive therapy for children with ureteric stones is safe and effective, as it facilitates spontaneous expulsion of the stone.

Matched pair analysis of ureteroscopy vs. shock wave lithotripsy for the treatment of upper ureteric calculi.

PubMed

Stewart, G D; Bariol, S V; Moussa, S A; Smith, G; Tolley, D A

2007-05-01

There is controversy over whether shock wave lithotripsy (SWL) or ureteroscopy (URS) is the best management of ureteric calculi, especially for stones located in the upper ureter. This study compares URS and SWL management of upper ureteric stones directly for the first time using a different analysis tool, the matched pair analysis study design. This method enables meaningful comparisons to be made on a small number of matched patients, using precise like-for-like matching. Adult patients undergoing primary treatment of solitary radiopaque proximal ureteric stones were identified. Patients with stents, nephrostomies or stones at the pelvi-ureteric junction were excluded. Patients had a minimum of 3 months follow-up. Patients treated by primary URS were matched using four parameters (sex, laterality, stone size and location) to patients treated on a Dornier Compact Delta Lithotriptor. A total of 1479 patients had URS or SWL from which 27 upper ureteric stone matched pairs were identified. Three-month stone free rates were 82% for URS and 89% for SWL (McNemar's test, p=0.625). Re-treatment was required in 11% and 26% following URS and SWL respectively (p=0.219). Forty-one per cent of URS patients required an ancillary treatment, such as stent removal, compared with only 22% of SWL patients (p=0.227). Introduction of a holmium:YAG laser for use with URS improved the stone free rate for URS to 100%. Using a robust like-for-like comparison of similar patients with very similar upper ureteric stones the outcomes following SWL and URS were comparable. Choice of treatment should therefore be based on parameters such as availability of equipment, waiting times and patient preference.

Validating automated kidney stone volumetry in computed tomography and mathematical correlation with estimated stone volume based on diameter.

PubMed

Wilhelm, Konrad; Miernik, Arkadiusz; Hein, Simon; Schlager, Daniel; Adams, Fabian; Benndorf, Matthias; Fritz, Benjamin; Langer, Mathias; Hesse, Albrecht; Schoenthaler, Martin; Neubauer, Jakob

2018-06-02

To validate AutoMated UroLithiasis Evaluation Tool (AMULET) software for kidney stone volumetry and compare its performance to standard clinical practice. Maximum diameter and volume of 96 urinary stones were measured as reference standard by three independent urologists. The same stones were positioned in an anthropomorphic phantom and CT scans acquired in standard settings. Three independent radiologists blinded to the reference values took manual measurements of the maximum diameter and automatic measurements of maximum diameter and volume. An "expected volume" was calculated based on manual diameter measurements using the formula: V=4/3 πr³. 96 stones were analyzed in the study. We had initially aimed to assess 100. Nine were replaced during data acquisition due of crumbling and 4 had to be excluded because the automated measurement did not work. Mean reference maximum diameter was 13.3 mm (5.2-32.1 mm). Correlation coefficients among all measured outcomes were compared. The correlation between the manual and automatic diameter measurements to the reference was 0.98 and 0.91, respectively (p<0.001). Mean reference volume was 1200 mm³ (10-9000 mm³). The correlation between the "expected volume" and automatically measured volume to the reference was 0.95 and 0.99, respectively (p<0.001). Patients' kidney stone burden is usually assessed according to maximum diameter. However, as most stones are not spherical, this entails a potential bias. Automated stone volumetry is possible and significantly more accurate than diameter-based volumetric calculations. To avoid bias in clinical trials, size should be measured as volume. However, automated diameter measurements are not as accurate as manual measurements.

Differences in stone size and ureteral dilation between obstructing proximal and distal ureteral calculi.

PubMed

Eisner, Brian H; Pedro, Renato; Namasivayam, Saravanan; Kambadakone, Avinash; Sahani, Dushyant V; Dretler, Stephen P; Monga, Manoj

2008-09-01

To examine the differences in ureteral dilation and calculus size between obstructing proximal and distal ureteral stones. A retrospective review of computed tomography (CT) scans from 176 consecutive patients with obstructing ureteral calculi was performed. For the calculi, the axial diameter was defined as the largest stone diameter on the axial CT images, and the coronal length was defined as the cephalocaudal length of the stone measured on the coronal CT images. Univariate and multivariate statistical analyses were performed. A total of 65 proximal and 111 distal ureteral calculi were analyzed. On univariate analysis, the proximal calculi were associated with a greater degree of ureteral dilation (mean 6.1 mm vs 5.3 mm, P = .01) and had a greater coronal length (mean 9.9 mm vs 8.3 mm, P = .005) than distal calculi. This association was also true on the multivariate analysis, which controlled for age and sex (P = .0004). No statistically significant difference was found in the axial calculus diameter for the proximal and distal stones (mean 5.3 mm vs 5.0 mm, P = .29). In a subset of 50 patients whose contralateral ureters (without stones) were measured for control comparison, the ureteral dilation in the ureters with stones was significantly greater than in the control ureters (proximal ureter 6.2 mm vs 4.3 mm, P = .001; distal ureter 4.7 mm vs 3.8 mm, P = .004). For proximal calculi, 72.3% were associated with ureteral dilation of less than 7 mm, 23.1% with 7-10 mm, and 4.6% with greater than 10 mm. For the distal calculi, 90.1% were associated with ureteral dilation of less than 7 mm, 6.3% with 7-10 mm, and 3.6% with greater than 10 mm. The coronal length was the largest measured diameter in 94% of the calculi, and the mean calculus coronal length was significantly greater than the mean axial diameter (8.9 mm vs 5.1 mm, respectively, P < .001). The results of our study have shown that proximal ureteral calculi are associated with a significantly greater degree of ureteral dilation and larger coronal length than are distal calculi. These findings should guide the endoscopist in planning intracorporeal ureteroscopic lithotripsy. We suggest obtaining CT coronal images to more accurately characterize obstructing ureteral stones.

Comparison between retrograde intrarenal surgery and extracorporeal shock wave lithotripsy in the treatment of lower pole kidney stones up to 15 mm. Prospective, randomized study.

PubMed

Vilches, R M; Aliaga, A; Reyes, D; Sepulveda, F; Mercado, A; Moya, F; Ledezma, R; Hidalgo, J P; Olmedo, T; Marchant, F

2015-05-01

Extracorporeal Shock Wave Lithotripsy (ESWL) is currently the recommended treatment for intra-renal calculi smaller than 2 cm. However the low Stone Free Rate (SFR) in lower pole calculi gives rise to new techniques, such us retrograde intrarenal surgery (RIRS), for improve the surgery outcomes. To compare the efficacy of a treatment with ESWL with RIRS, in terms of SFR after surgery, in patients with kidney stones up to 15 mm in the lower pole. A prospective study was carried out in order to assess the results of ESWL and RIRS in patients with lower pole stones less than 15 mm. Among a total of 55 patients, 31 were underwent to ESWL (Group 1) and the remaining 24 to RIRS (Group 2). Clinical data recorded, including general characteristics of each patient, were: calculi size, side, operative time, complications according to Clavien scale, SFR and the presence of residual fragments at 2 months post-treatment assessed by a CT scan. STATA 11 was used to perform the statistical analysis. There were no differences for general descriptors among groups with the exception of a significantly longer operative time for RIRS. The rates of SFR and residual fragments lesser than 3 mm. were lower in the RIRS group than in ESWL ones. RIRS also showed a lower rate of clinically significant fragments (0% vs 42.3%. P < .05). In the subgroup of patients with stones between 10/15 mm RIRS showed higher SFR (75% vs. 41.2%) and a lower rate of stones>3 mm (0% vs. 58.8%), being statistically significant (P < .05). Clavien III or higher complications were not reported in any of the groups. In the treatment of lower pole stone RIRS has the same results than ESWL in terms of SFR. Regarding absence of a clinically significant residual fragment, RIRS was superior to ESWL. A bigger sample size is required in order to confirm this results. Copyright © 2014 AEU. Publicado por Elsevier España, S.L.U. All rights reserved.

Material decomposition images generated from spectral CT: detectability of urinary calculi and influencing factors.

PubMed

Lv, Peijie; Zhang, Yonggao; Liu, Jie; Ji, Lijuan; Chen, Yan; Gao, Jianbo

2014-01-01

To evaluate the detectability of urinary calculi on material decomposition (MD) images generated from spectral computed tomography (CT) and identify the influencing factors. Forty-six patients were examined with true nonenhanced (TNE) CT and spectral CT urography in the excretory phase. The contrast medium was removed from excretory phase images using water-based (WB) and calcium-based (CaB) MD analysis. The sensitivity for detection on WB and CaB images was evaluated using TNE results as the reference standard. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) on MD images were evaluated. Using logistic regression, the influences of image noise, attenuation, stone size, and patient's body mass index (BMI) were assessed. Threshold values with maximal sensitivity and specificity were calculated by means of receiver operating characteristic analyses. One hundred thirty-six calculi were detected on TNE images; 98 calculi were identified on WB images (sensitivity, 72.06%) and 101 calculi on CaB images (sensitivity, 74.26%). Sensitivities were 76.92% for the 3-5-mm stones and 84.51% for the 5-mm or larger stones on both WB and CaB images but reduced to 46.15% on WB images and 53.85% on CaB images for small calculi (<3 mm). Compared to WB images, CaB images showed lower image noise, higher SNR but similar CNR. Larger stone sizes (both >2.71 mm on WB and CaB) and greater CT attenuation (>280 Hounsfield units [HU] on WB, >215 HU on CaB) of the urinary stones were significantly associated with higher stone visibility rates on WB and CaB images (P ≤ .003). Image noise and BMI showed no impact on the stone detection. MD images generated from spectral CT showed good reliability for the detection of large (>2.71 mm) and hyperattenuating (>280 HU on WB, >215 HU on CaB) urinary calculi. Copyright © 2014 AUR. Published by Elsevier Inc. All rights reserved.

Impact of Pretreatment Hydronephrosis on the Success Rate of Shock Wave Lithotripsy in Patients with Ureteral Stone.

PubMed

Chang, Ki Don; Lee, Joo Yong; Park, Sung Yoon; Kang, Dong Hyuk; Lee, Hyung Ho; Cho, Kang Su

2017-09-01

To evaluate predictors of the success rate for one session of shock wave lithotripsy (SWL), focusing on the relationships between pretreatment hydronephrosis grade and one-session SWL success rates. The medical records of 1824 consecutive patients who underwent an initial session of SWL for treatment of urinary stones between 2005 and 2013 were reviewed. After exclusion, 700 patients with a single, 4-20 mm diameter radiopaque calculus were included in the study. The mean maximal stone length (MSL) and skin-to-stone distance were 9.2±3.9 and 110.8±18.9 mm, respectively. The average values for mean stone density (MSD) and stone heterogeneity index (SHI) were 707.0±272.1 and 244.9±110.1, respectively. One-session success rates were 68.4, 75.0, 75.1, 54.0, and 10.5% in patients with hydronephrosis grade 0, 1, 2, 3, and 4, respectively. Patients were classified into success or failure groups based on SWL outcome. Multivariate logistic regression analyses revealed that MSL [odds ratio (OR) 0.888, 95% confidence intervals (CI): 0.841-0.934, p<0.001], MSD (OR 0.996, 95% CI: 0.995-0.997, p<0.001), SHI (OR 1.007, 95% CI: 1.005-1.010, p<0.001), and pretreatment hydronephrosis grade (OR 0.601, 95% CI: 0.368-0.988, p=0.043) were significantly associated with one-session success. Pretreatment grades 3 or 4 hydronephrosis were associated with failure of SWL in patients with a single ureteral stone. In the presence of severe hydronephrosis, especially hydronephrosis grade 4; physicians should proceed cautiously in choosing and offering SWL as the primary treatment for ureteral stone. © Copyright: Yonsei University College of Medicine 2017

Impact of Pretreatment Hydronephrosis on the Success Rate of Shock Wave Lithotripsy in Patients with Ureteral Stone

PubMed Central

Chang, Ki Don; Lee, Joo Yong; Park, Sung Yoon; Kang, Dong Hyuk; Lee, Hyung Ho

2017-01-01

Purpose To evaluate predictors of the success rate for one session of shock wave lithotripsy (SWL), focusing on the relationships between pretreatment hydronephrosis grade and one-session SWL success rates. Materials and Methods The medical records of 1824 consecutive patients who underwent an initial session of SWL for treatment of urinary stones between 2005 and 2013 were reviewed. After exclusion, 700 patients with a single, 4–20 mm diameter radiopaque calculus were included in the study. Results The mean maximal stone length (MSL) and skin-to-stone distance were 9.2±3.9 and 110.8±18.9 mm, respectively. The average values for mean stone density (MSD) and stone heterogeneity index (SHI) were 707.0±272.1 and 244.9±110.1, respectively. One-session success rates were 68.4, 75.0, 75.1, 54.0, and 10.5% in patients with hydronephrosis grade 0, 1, 2, 3, and 4, respectively. Patients were classified into success or failure groups based on SWL outcome. Multivariate logistic regression analyses revealed that MSL [odds ratio (OR) 0.888, 95% confidence intervals (CI): 0.841–0.934, p<0.001], MSD (OR 0.996, 95% CI: 0.995–0.997, p<0.001), SHI (OR 1.007, 95% CI: 1.005–1.010, p<0.001), and pretreatment hydronephrosis grade (OR 0.601, 95% CI: 0.368–0.988, p=0.043) were significantly associated with one-session success. Conclusion Pretreatment grades 3 or 4 hydronephrosis were associated with failure of SWL in patients with a single ureteral stone. In the presence of severe hydronephrosis, especially hydronephrosis grade 4; physicians should proceed cautiously in choosing and offering SWL as the primary treatment for ureteral stone. PMID:28792145

What is the quickest scoring system to predict percutaneous nephrolithotomy outcomes? A comparative study among S.T.O.N.E score, guy's stone score and croes nomogram.

PubMed

Vicentini, Fabio C; Serzedello, Felipe R; Thomas, Kay; Marchini, Giovanni S; Torricelli, Fabio C M; Srougi, Miguel; Mazzucchi, Eduardo

2017-01-01

To compare the application time and the capacity of the nomograms to predict the success of Guy's Stone Score (GSS), S.T.O.N.E. Nephrolithometry (STONE) and Clinical Research Office of the Endourological Society nephrolithometric nomogram (CROES) of percutaneous nephrolithotomy (PCNL), evaluating the most efficient one for clinical use. We studied 48 patients who underwent PCNL by the same surgeon between 2010 and 2011. We calculated GSS, STONE and CROES based on preoperative non-contrast computed tomography (CT) images and clinical data. A single observer, blinded to the outcomes, reviewed all images and assigned scores. We compared the application time of each nomogram. We used an analysis of variance for repeated measures and multiple comparisons by the Tukey test. We compared the area under the ROC curve (AUC) of the three nomograms two by two to determine the most predictive scoring system. The immediate success rate was 66.7% and complications occurred in 16.7% of cases. The average operative time was 122 minutes. Mean application time was significantly lower for the GSS (27.5 seconds) when compared to 300.6 seconds for STONE and 213.4 seconds for CROES (p<0.001). There was no significant difference among the GSS (AUC=0.653), STONE (AUC=0.563) and CROES (AUC=0.641) in the ability to predict immediate success of PCNL. All three nomograms showed similar ability to predict success of PCNL, however the GSS was the quickest to be applied, what is an important issue for routine clinical use when counseling patients who are candidates to PCNL. Copyright® by the International Brazilian Journal of Urology.

What is the quickest scoring system to predict percutaneous nephrolithotomy outcomes? A comparative study among S.T.O.N.E score, Guy's Stone Ccore and CROES nomogram

PubMed Central

Vicentini, Fabio C.; Serzedello, Felipe R.; Thomas, Kay; Marchini, Giovanni S.; Torricelli, Fabio C. M.; Srougi, Miguel; Mazzucchi, Eduardo

2017-01-01

ABSTRACT Objective: To compare the application time and the capacity of the nomograms to predict the success of Guy's Stone Score (GSS), S.T.O.N.E. Nephrolithometry (STONE) and Clinical Research Office of the Endourological Society nephrolithometric nomogram (CROES) of percutaneous nephrolithotomy (PCNL), evaluating the most efficient one for clinical use. Materials and Methods: We studied 48 patients who underwent PCNL by the same surgeon between 2010 and 2011. We calculated GSS, STONE and CROES based on pre-operative non-contrast computed tomography (CT) images and clinical data. A single observer, blinded to the outcomes, reviewed all images and assigned scores. We compared the application time of each nomogram. We used an analysis of variance for repeated measures and multiple comparisons by the Tukey test. We compared the area under the ROC curve (AUC) of the three nomograms two by two to determine the most predictive scoring system. Results: The immediate success rate was 66.7% and complications occurred in 16.7% of cases. The average operative time was 122 minutes. Mean application time was significantly lower for the GSS (27.5 seconds) when compared to 300.6 seconds for STONE and 213.4 seconds for CROES (p<0.001). There was no significant difference among the GSS (AUC=0.653), STONE (AUC=0.563) and CROES (AUC=0.641) in the ability to predict immediate success of PCNL. Conclusions: All three nomograms showed similar ability to predict success of PCNL, however the GSS was the quickest to be applied, what is an important issue for routine clinical use when counseling patients who are candidates to PCNL. PMID:28338303

Successful topical dissolution of cholesterol gallbladder stones using ethyl propionate.

PubMed

Hofmann, A F; Amelsberg, A; Esch, O; Schteingart, C D; Lyche, K; Jinich, H; Vansonnenberg, E; D'Agostino, H B

1997-06-01

Topical dissolution of cholesterol gallbladder stones using methyl tert-butyl ether (MTBE) is useful in symptomatic patients judged too ill for surgery. Previous studies showed that ethyl propionate (EP), a C5 ester, dissolves cholesterol gallstones rapidly in vitro, but differs from MTBE in being eliminated so rapidly by the liver that blood levels remain undetectable. Our aim was to test EP as a topical dissolution agent for cholesterol gallbladder stones. Five high-risk patients underwent topical dissolution of gallbladder stones by EP. In three patients, the solvent was instilled via a cholecystostomy tube placed previously to treat acute cholecystitis; in two patients, a percutaneous transhepatic catheter was placed in the gallbladder electively. Gallstone dissolution was assessed by chromatography, by gravimetry, and by catheter cholecystography. Total dissolution of gallstones was obtained in four patients after 6-10 hr of lavage; in the fifth patient, partial gallstone dissolution facilitated basketing of the stones. In two patients, cholesterol dissolution was measured and averaged 30 mg/min. Side effects were limited to one episode of transient hypotension and pain at the infusion site; no patient developed somnolence or nausea. Gallstone elimination was associated with relief of symptoms. EP is an acceptable alternative to MTBE for topical dissolution of cholesterol gallbladder stones in high-risk patients. The lower volatility and rapid hepatic extraction of EP suggest that it may be preferable to MTBE in this investigational procedure.

Influence of Pore Structure on the Effectiveness of a Biogenic Carbonate Surface Treatment for Limestone Conservation ▿

PubMed Central

De Muynck, Willem; Leuridan, Stijn; Van Loo, Denis; Verbeken, Kim; Cnudde, Veerle; De Belie, Nele; Verstraete, Willy

2011-01-01

A ureolytic biodeposition treatment was applied to five types of limestone in order to investigate the effect of pore structure on the protective performance of a biogenic carbonate surface treatment. Protective performance was assessed by means of transport and degradation processes, and the penetration depth of the treatment was visualized by microtomography. Pore size governs bacterial adsorption and hence the location and amount of carbonate precipitated. This study indicated that in macroporous stone, biogenic carbonate formation occurred to a larger extent and at greater depths than in microporous stone. As a consequence, the biodeposition treatment exhibited the greatest protective performance on macroporous stone. While precipitation was limited to the outer surface of microporous stone, biogenic carbonate formation occurred at depths of greater than 2 mm for Savonnières and Euville. For Savonnières, the presence of biogenic carbonate resulted in a 20-fold decreased rate of water absorption, which resulted in increased resistance to sodium sulfate attack and to freezing and thawing. While untreated samples were completely degraded after 15 cycles of salt attack, no damage was observed in biodeposition-treated Savonnières. From this study, it is clear that biodeposition is very effective and more feasible for macroporous stones than for microporous stones. PMID:21821746

Influence of pore structure on the effectiveness of a biogenic carbonate surface treatment for limestone conservation.

PubMed

De Muynck, Willem; Leuridan, Stijn; Van Loo, Denis; Verbeken, Kim; Cnudde, Veerle; De Belie, Nele; Verstraete, Willy

2011-10-01

A ureolytic biodeposition treatment was applied to five types of limestone in order to investigate the effect of pore structure on the protective performance of a biogenic carbonate surface treatment. Protective performance was assessed by means of transport and degradation processes, and the penetration depth of the treatment was visualized by microtomography. Pore size governs bacterial adsorption and hence the location and amount of carbonate precipitated. This study indicated that in macroporous stone, biogenic carbonate formation occurred to a larger extent and at greater depths than in microporous stone. As a consequence, the biodeposition treatment exhibited the greatest protective performance on macroporous stone. While precipitation was limited to the outer surface of microporous stone, biogenic carbonate formation occurred at depths of greater than 2 mm for Savonnières and Euville. For Savonnières, the presence of biogenic carbonate resulted in a 20-fold decreased rate of water absorption, which resulted in increased resistance to sodium sulfate attack and to freezing and thawing. While untreated samples were completely degraded after 15 cycles of salt attack, no damage was observed in biodeposition-treated Savonnières. From this study, it is clear that biodeposition is very effective and more feasible for macroporous stones than for microporous stones.

Black dimensional stones: Geology, technical properties and deposit characterization of the dolerites from Uruguay

NASA Astrophysics Data System (ADS)

Morales Demarco, M.; Oyhantçabal, P.; Stein, K.-J.; Siegesmund, S.

2012-04-01

Dimensional stones with a black color occupy a prominent place on the international market. Uruguayan dolerite dikes of andesitic and andesitic-basaltic composition are mined for commercial blocks of black dimensional stones. A total of 16 dikes of both compositions were studied and samples collected for geochemical and petrographical analysis. Color measurements were performed on different black dimensional stones in order to compare them with the Uruguayan dolerites. Samples of the two commercial varieties (Absolute Black and Moderate Black) were obtained for petrophysical analysis (e.g. density, porosity, uniaxial compressive strength, tensile strength, etc.). Detailed structural analyses were performed in several quarries. Geochemistry and petrography determines the intensity of the black color. When compared with commercial samples from China, Brazil, India and South Africa, among others, the Uruguayan dolerite Absolute Black is the darkest black dimensional stone analyzed. In addition, the petrophysical properties of the Uruguayan dolerites make them one of the highest quality black dimensional stones. Structural analyses show that five joint sets have been recognized: two sub-vertical joints, one horizontal and two diagonal. These joint sets are one of the most important factors that control the deposits, since they control the block size distribution and the amount of waste material.

Extracorporeal shock wave lithotripsy of gallstones with oral dissolution. Results in course of ten years in Czech Republic in correlation to indication criteria.

PubMed

Benes, J; Chmel, J; Blazek, O; Marecek, Z

2001-01-01

We compared the results of treatment of gallbladder stones by extracorporeal shock wave lithotripsy with dissolution during two periods to different criteria of indication. In the first period (1990-1991) we treated patients with stones up to 3 cm in diameter. In the second period (1992-1994) the indication included stones up to 1.5 cm with gallbladder contraction on cholecystography, which was also quantitatively determined by USG exceeding 60% of fasting volume. We used Czech made lithotriptors MEDILIT. The shock waves (SW) are produced by an underwater high voltage discharge and the concentration of SW is achieved by reflection. The localization of stones is performed by means of a sonographic probe. After stone localization usually 700 SW are applied to a patient lying in prone position. Oral dissolution was started in both groups of patients two weeks before shock wave application. Ursodeoxycholic acid and chenodeoxycholic were administered in doses of 7.5 mg/kg body weight/day. In the first group of 260 patients (average age 42), which had moderate indication criteria, disappearance of fragments during one year was found only in 148 (57%). The remaining patients were treated symptomatically or recommended to cholecystectomy. In a second group of 160 patients (average age 45), disappearance of fragments during one year was achieved in 125 (78%). We used stricter indication criteria and our results are much better compared to the first group. Only 208 patients from both groups were controlled for more 5 years, in 89 cases of this number was a recidivity of lithiasis and at 20 of them we indicated cholecystectomy, 22 of the patients refused to continue in the therapy, because the stones are asymptomatic. In our opinion, this therapy (ESWL combined with oral dissolution) is suitable in 7% patients with gallbladder stones. Its side effects are very small, practically negligible. It can be performed without general anaesthesia and on an out-patient basis. After the advent of laparoscopic cholecystectomy we observed diminished interest of both patients and their physicians for gallbladder ESWL, however, after it has reached a widespread use, a new interest in ESWL and dissolution therapy is emerging, which we attribute to its above-mentioned advantages.

Safety and feasibility of day case ureteroscopy and laser lithotripsy (URSL) in patients with a solitary kidney.

PubMed

Ghosh, Anngona; Somani, Bhaskar K

2016-01-01

The management of nephrolithiasis in patients with a solitary kidney poses a treatment challenge. The study aimed to evaluate the outcomes of ureteroscopy and laser stone fragmentation (URSL) for renal stones in these patients treated in our university teaching hospital. Between July 2012 and December 2014, seventeen cases of URSL for stones in a solitary kidney were reviewed. Patient demographics, stone dimensions, perioperative and post-operative outcomes were recorded in a prospectively maintained database. Serum creatinine levels pre-procedure and at follow-up were also compared. Seventeen cases of URSL were conducted with a mean age of 52.9 ±19.9 years. 8 of the 17 (47%) patients had stones in multiple locations and 13 (76%) were in the lower pole. The mean ± SD stone size and BMI were 13.0 ±8.9 mm and 31.6 ±5.8 kg/m(2), respectively. The stone free rate (SFR) was 82.5%. Fourteen (82.5%) patients were discharged the same day and 16 cases (94%) were discharged within 24 hours. For patients with deranged pre-operative serum creatinine, the mean serum creatinine level improved from 131.2 ±68.3 µmol/L pre-URSL to 106.5 ±36.7 µmol/L at follow-up. There was one Clavien grade II complication with a patient requiring additional antibiotics for post-operative urinary tract infection. There were no other major or minor complications. Day case ureteroscopy for stone disease in a solitary kidney is safe and feasible with a low complication rate and an overall improvement in renal function.

Minimally invasive PCNL-MIP.

PubMed

Zanetti, Stefano Paolo; Boeri, Luca; Gallioli, Andrea; Talso, Michele; Montanari, Emanuele

2017-01-01

Miniaturized percutaneous nephrolithotomy (mini-PCNL) has increased in popularity in recent years and is now widely used to overcome the therapeutic gap between conventional PCNL and less-invasive procedures such as shock wave lithotripsy (SWL) or flexible ureterorenoscopy (URS) for the treatment of renal stones. However, despite its minimally invasive nature, the superiority in terms of safety, as well as the similar efficacy of mini-PCNL compared to conventional procedures, is still under debate. The aim of this chapter is to present one of the most recent advancements in terms of mini-PCNL: the Karl Storz "minimally invasive PCNL" (MIP). A literature search for original and review articles either published or e-published up to December 2016 was performed using Google and the PubMed database. Keywords included: minimally invasive PCNL; MIP. The retrieved articles were gathered and examined. The complete MIP set is composed of different sized rigid metallic fiber-optic nephroscopes and different sized metallic operating sheaths, according to which the MIP is categorized into extra-small (XS), small (S), medium (M) and large (L). Dilation can be performed either in one-step or with a progressive technique, as needed. The reusable devices of the MIP and vacuum cleaner efect make PCNL with this set a cheap procedure. The possibility to shift from a small to a larger instrument within the same set (Matrioska technique) makes MIP a very versatile technique suitable for the treatment of almost any stone. Studies in the literature have shown that MIP is equally effective, with comparable rates of post-operative complications, as conventional PCNL, independently from stone size. MIP does not represent a new technique, but rather a combination of the last ten years of PCNL improvements in a single system that can transversally cover all available techniques in the panorama of percutaneous stone treatment.

A comparison of different activated carbon performances on catalytic ozonation of a model azo reactive dye.

PubMed

Gül, S; Eren, O; Kır, S; Onal, Y

2012-01-01

The objective of this study is to compare the performances of catalytic ozonation processes of two activated carbons prepared from olive stone (ACOS) and apricot stone (ACAS) with commercial ones (granular activated carbon-GAC and powder activated carbon-PAC) in degradation of reactive azo dye (Reactive Red 195). The optimum conditions (solution pH and amount of catalyst) were investigated by using absorbencies at 532, 220 and 280 nm wavelengths. Pore properties of the activated carbon (AC) such as BET surface area, pore volume, pore size distribution, and pore diameter were characterized by N(2) adsorption. The highest BET surface area carbon (1,275 m(2)/g) was obtained from ACOS with a particle size of 2.29 nm. After 2 min of catalytic ozonation, decolorization performances of ACOS and ACAS (90.4 and 91.3%, respectively) were better than that of GAC and PAC (84.6 and 81.2%, respectively). Experimental results showed that production of porous ACs with high surface area from olive and apricot stones is feasible in Turkey.

Bondonic effects in group-IV honeycomb nanoribbons with Stone-Wales topological defects.

PubMed

Putz, Mihai V; Ori, Ottorino

2014-04-03

This work advances the modeling of bondonic effects on graphenic and honeycomb structures, with an original two-fold generalization: (i) by employing the fourth order path integral bondonic formalism in considering the high order derivatives of the Wiener topological potential of those 1D systems; and (ii) by modeling a class of honeycomb defective structures starting from graphene, the carbon-based reference case, and then generalizing the treatment to Si (silicene), Ge (germanene), Sn (stannene) by using the fermionic two-degenerate statistical states function in terms of electronegativity. The honeycomb nanostructures present η-sized Stone-Wales topological defects, the isomeric dislocation dipoles originally called by authors Stone-Wales wave or SWw. For these defective nanoribbons the bondonic formalism foresees a specific phase-transition whose critical behavior shows typical bondonic fast critical time and bonding energies. The quantum transition of the ideal-to-defect structural transformations is fully described by computing the caloric capacities for nanostructures triggered by η-sized topological isomerisations. Present model may be easily applied to hetero-combinations of Group-IV elements like C-Si, C-Ge, C-Sn, Si-Ge, Si-Sn, Ge-Sn.

Quality of life and urolithiasis: the patient - reported outcomes measurement information system (PROMIS).

PubMed

Patel, Nishant; Brown, Robert D; Sarkissian, Carl; De, Shubha; Monga, Manoj

2017-01-01

With a high rate of recurrence, urolithiasis is a chronic disease that impacts quality of life. The Patient Reported Outcomes Measurement Information System is an NIH validated questionnaire to assess patient quality of life. We evaluated the impact of urolithiasis on quality of life using the NIH-sponsored PROMIS-43 questionnaire. Patients reporting to the kidney stone clinic were interviewed to collect information on stone history and demographic information and were asked to complete the PROMIS-43 questionnaire. Quality of life scores were analyzed using gender and age matched groups for the general US population. Statistical comparisons were made based on demographic information and patient stone history. Statistical significance was P<0.05. 103 patients completed the survey. 36% of respondents were male, the average age of the group was 52 years old, with 58% primary income earners, and 35% primary caregivers. 7% had never passed a stone or had a procedure while 17% passed 10 or more stones in their lifetime. Overall, pain and physical function were worse in patients with urolithiasis. Primary income earners had better quality of life while primary caregivers and those with other chronic medical conditions were worse. Patients on dietary and medical therapy had better quality of life scores. Urolithiasis patients subjectively have worse pain and physical function than the general population. The impact of pain on quality of life was greatest in those patients who had more stone episodes, underscoring the importance of preventive measures. Stone prevention measures improve quality of life. Copyright® by the International Brazilian Journal of Urology.

Function investigation of stone mastic asphalt (SMA) mixture partly containing basic oxygen furnace (BOF) slag.

PubMed

Chen, Zongwu; Wu, Shaopeng; Pang, Ling; Xie, Jun

2016-07-04

In this paper, the effect of the size gradations of basic oxygen furnace (BOF) slag on the functional performances of stone mastic asphalt (SMA) mixture including skid and deformation resistances was investigated. The industrially produced BOF slag coarse aggregates (BSCA) with size gradations of 4.75-9.5 mm and 9.5-16 mm were used. SMA mixtures were designed according to Marshall procedure. British pendulum number (BPN), indicating the skid resistance of asphalt mixture, was measured by a British pendulum skid resistance device. Flow number (FN) and Marshall quotient (MQ), reflecting the deformation resistance of asphalt mixture, were determined, respectively, based on the results of dynamic creep test and Marshall test (stability and flow value). Showed that BSCA with a size gradation of 9.5-16 mm performed better in improving the skid and deformation resistance of SMA mixture than BSCA with a size gradation of 4.75-9.5 mm. Furthermore, BSCA with combined size gradations, namely, 4.75-16 mm, worked the best. These conclusions would benefit the future extensive utilization of BSCA in asphalt pavement.

The usefulness of densitometry in predicting the composition and fragility of urolithiasis.

PubMed

Argüelles-Salido, Enrique; Lozano-Blasco, Jose Maria; Subira-Rios, Jorge; Bernardo-Villar, Pastora; Podio-Lora, Virtudes; Campoy-Martínez, Pedro; Vazquez-Albertino, Ricardo; Medina-Lopez, Rafael

2014-04-01

The choice of ideal treatment for a given lithiasis is a crucial factor for its success, minimizing the number of interventions and complications. Previous determination of stone composition and its fragility is desirable, to predict its behavior during extracorporeal shock wave lithotripsy and for evaluation of its appropriateness, or to set the indication for other techniques. To determine the role of densitometry in the prediction of composition and fragility of urinary lithiasis undergoing SWL. Experimental prospective, blinded, in vitro study using 193 urinary calculi of known composition : monohydrated calcium oxalate, mixed calcium oxalate, uric acid, and calcium carbonate, obtained from spontaneous passage or surgery. Densitometry and SWL were performed on them. We compare the mineral composition of the stone and mineral density of each composition group to check if they are characteristic of each type and correlate these parameters with the energy dose required to fragment them down to a given fragment size. Only 53 out of 193 stones showed valuable data. Calcium carbonate was the composition showing grater mineral content and density (1,24 gr and 0,47 gr/cm2), followed by mixed oxalate (0,51/0,26) and uric acid (0,52/ 0,15), finishing with the monohydrate calcium oxalate group (0,32/0,05).Only the comparison between calcium carbonate and monohydrated calcium oxalate showed statistically significant results (p<0,05). Correlation coefficients between mineral content (0,347) and density (0,424) and the energy used for stone fragmentation to a given fragment size were statistically significant (p<0,05) CONCLUSIONS: In our study, the use of densitometry to determine stone composition and lithiasic fragility did not show conclusive results due to the limited number of calculi tested. Nevertheless, there are signs that, with a different study design , more practically useful results could be achieved.

Incidence and Predictors for Ipsilateral Hydronephrosis Following Ureteroscopic Lithotripsy.

PubMed

Barbour, Meredith L; Raman, Jay D

2015-09-01

To review our experience in using ureteroscopy (URS) with lithotripsy for renal or ureteral calculi to determine the incidence and predictors of postprocedural ipsilateral hydronephrosis. Records of 324 URS cases for renal or ureteral calculi with imaging performed 4-12 weeks postprocedure were reviewed. Ipsilateral hydronephrosis was determined by computed tomography scan or renal ultrasound. Univariate and multivariate analyses determined the factors associated with hydronephrosis. 176 men and 148 women with a median age of 50 years were included. Median stone size was 6 mm and operative duration was 60 minutes; 30% of patients had multiple calculi; and 35% had undergone a prior ipsilateral URS. Overall, 49 of 324 patients (15%) had evidence of hydronephrosis, with 65% of these patients having symptoms and 40% requiring ancillary procedures. On multivariate analysis, increasing stone diameter (odds ratio [OR] 8.9, 95% confidence interval [CI] 1.9-23.8, P = .03), prior ipsilateral URS (OR 7.7, 95% CI 1.8-28.2, P = .006), longer operative duration (OR 6.5, 95% CI 1.8-16.3, P = .02), and renal colic symptoms (OR 48.3, 95% CI 14.7-71.4, P <.001) independently predicted hydronephrosis. Conversely, other factors including stone impaction at procedure, ureteral dilation, use of an access sheath, intraoperative perforation, or use of a stent did not associate with ipsilateral hydronephrosis. In this contemporary cohort study, 15% of patients undergoing URS had evidence of ipsilateral hydronephrosis. Larger stone size, longer OR duration, prior ipsilateral URS, and recurrent colic were associated with an increased likelihood for this observation. Patients and stone cases with such characteristics likely warrant imaging modalities beyond plain radiography. Copyright © 2015 Elsevier Inc. All rights reserved.

Pure ultrasonography-guided radiation-free percutaneous nephrolithotomy: report of 357 cases.

PubMed

Hosseini, Mohammad Mehdi; Yousefi, Alireza; Rastegari, Mohsen

2015-01-01

To assess the safety and effectiveness of pure ultrasound-guided percutaneous nephrolithotomy. Three hundred fifty-seven patients were treated; 139 women and 218 men, with a mean age of 33.7 years (range 21-69 years) and a mean stone size of 33.5 mm in maximum diameter (range 20-52 mm). Stone locations were renal pelvis (174), lower calyx (68) or both (115) with mild to moderate hydronephrosis seen on excretory urography. A ureteral stent was inserted by cystoscope, and saline was injected for better localization of the pelvicaliceal system (PCS), if needed. Puncture of the PCS was done by an 18-gauge nephrostomy needle through the lower pole calyx, and all the steps, including dilatation, were done under the guidance of ultrasonography. The day after the operation, 318 (89.07%) patients were stone-free in the kidneys, ureters, and bladder x-rays. Nineteen patients (5.3%) had multiple fragments that measured equal or less than 5 mm and passed them spontaneously in 2-4 weeks (total stone-free rate 94.4%). Access failure occurred in ten obese patients (2.8%) and fluoroscopy was required. Residual fragments with sizes of 10-12 mm were seen in seven patients, all of who underwent shock wave lithotripsy. In one patient, a fragment measuring 7-8 mm migrated into the distal part of the ureter. It was fragmented with ureteroscopy and pneumatic lithoclast 2 days after the operation. In two patients who had large (>15 mm) residual stone redo percutaneous nephrolithotomy was performed 48 h after the first procedure. Percutaneous nephrolithotomy guided by ultrasonography seems to be as effective as fluoroscopy in selected cases and poses no risk of surgeon and patient exposure to radiation; however, more experience is required.

Endolithic diversity of microorganisms on sandstone and implications for biogenic weathering

NASA Astrophysics Data System (ADS)

Hallmann, C.; Friedenberger, H.; Hoppert, M.

2012-04-01

Molecular methods allow a comprehensive view on uncultured microbial communities in dimension stone. In the presented study, we focus on depth profiles of microbial colonization in sandstones with different porosity and overall durability. All sandstones were taken from quarries where they were exposed to the environment for several years. Approximately 0.1 g of material from the stone surface, from 5 mm and from 30 mm depths was taken under sterile conditions and subjected to analysis of microbial DNA and culturing experiments. In particular, DNA was extracted from the material, the phylogenetic marker gene of eukaryotic organisms (18S rDNA) was amplified and used for generation of clone libraries, which were then analysed by sequencing. "Roter Wesersandstein" was just colonized at the material surface, predominantly with algal and fungal microorganisms. No environmental DNA could be isolated from depth profiles. From "Nebraer Sandstein" with high pore size (shown by thin sections), environmental DNA from depths down to 3 cm could be retrieved. Though the uppermost layer is dominated by microalgae (as concluded from the retrieved clones), the percentage of algal clones from 5 mm and 30 mm depths drop to 10 % of all clones. There, apart from filamentous fungi, moss clones clearly dominate the microbial community. At a depth of 30 mm, 70-80 % of the retrieved clones match to various mosses (Bryophyta). Though mosses do not form layers on the stone surfaces, moss rhizoids or protonemata must be abundant as endoliths inside the stone material. It is reasonable to assume that the rhizoids may contribute to an increase in pore size by active penetration of the clastic material, even though colonization of the surface by mosses is not obvious. This feature may imply stronger impact of stone decay induced by endolithic growth of bryophytes than hitherto observed.

Outcomes of flexible ureterorenoscopy and laser fragmentation for renal stones: comparison between digital and conventional ureteroscope.

PubMed

Somani, Bhaskar K; Al-Qahtani, Saeed M; de Medina, Sixtina Diez Gil; Traxer, Olivier

2013-11-01

To compare the outcomes of flexible ureterorenoscopy and lasertripsy (FURS) using digital and conventional FURS for kidney stones. From September 2007 to April 2011, 118 patients underwent FURS (by the same surgeon). The outcomes were compared between equal numbers of procedures (59 each) using a conventional flexible ureterorenoscope (C-FURS; Olympus URF-P5) and a digital flexible ureterorenoscope (D-FURS; Olympus URF-V). Although the deflection, working channel, and field view are similar in both, the initial and terminal diameter is 8.4F and 9.9F and 6.9F and 8.4F for the D-FURS and C-FURS, respectively. The mean stone fragmentation time was calculated by the size per operative time. The preoperative, operative, and postoperative data were retrospectively analyzed and compared. The patient demographics were comparable. The mean stone size was 12.8 and 12 mm in the C-FURS and D-FURS groups, respectively. The initial assessment of the entire pyelocaliceal system was possible in 58 of 59 cases (98%) in the C-FURS group and 56 of 59 cases (94%) in the D-FURS group. The mean operative time was significantly longer in the C-FURS group (53.8 ± 15.2 minutes vs 44.5 ± 14.9 minutes). The overall stone-free rate 1 month after the procedure was 86% in the C-FURS group and 88% in the D-FURS group. Although on comparison, the D-FURS had slightly limited maneuverability, comparable success rates can be achieved with both conventional and digital ureteroscopes. D-FURSs significantly reduced the operative time compared with C-FURSs. Copyright © 2013 Elsevier Inc. All rights reserved.

Temperature and moisture conditions for life in the extreme arid region of the Atacama desert: four years of observations including the El Nino of 1997-1998

NASA Technical Reports Server (NTRS)

McKay, Christopher P.; Friedmann, E. Imre; Gomez-Silva, Benito; Caceres-Villanueva, Luis; Andersen, Dale T.; Landheim, Ragnhild

2003-01-01

The Atacama along the Pacific Coast of Chile and Peru is one of the driest and possibly oldest deserts in the world. It represents an extreme habitat for life on Earth and is an analog for life in dry conditions on Mars. We report on four years (September 1994-October 1998) of climate and moisture data from the extreme arid region of the Atacama. Our data are focused on understanding moisture sources and their role in creating suitable environments for photosynthetic microorganisms in the desert surface. The average air temperature was 16.5 degrees C and 16.6 degrees C in 1995 and 1996, respectively. The maximum air temperature recorded was 37.9 degrees C, and the minimum was -5.7 degrees C. Annual average sunlight was 336 and 335 W m(-2) in 1995 and 1996, respectively. Winds averaged a few meters per second, with strong fohn winds coming from the west exceeding 12 m s(-1). During our 4 years of observation there was only one significant rain event of 2.3 mm, which occurred near midnight local time. We suggest that this event was a rainout of a heavy fog. It is of interest that the strong El Nino of 1997-1998 brought heavy rainfall to the deserts of Peru, but did not bring significant rain to the central Atacama in Chile. Dew occurred at our station frequently following high nighttime relative humidity, but is not a significant source of moisture in the soil or under stones. Groundwater also does not contribute to surface moisture. Only the one rain event of 2.3 mm resulted in liquid water in the soil and beneath stones for a total of only 65-85 h over 4 years. The paucity of liquid water under stones is consistent with the apparent absence of hypolithic (under-stone) cyanobacteria, the only known primary producers in such extreme deserts.

Composition, Respirable Fraction and Dissolution Rate of 24 Stone Wool MMVF with their Binder.

PubMed

Wohlleben, Wendel; Waindok, Hubert; Daumann, Björn; Werle, Kai; Drum, Melanie; Egenolf, Heiko

2017-08-07

Man-made vitreous fibres (MMVF) are produced on a large scale for thermal insulation purposes. After extensive studies of fibre effects in the 1980ies and 1990ies, the composition of MMVF was modified to reduce the fibrotic and cancerogenic potential via reduced biopersistence. However, occupational risks by handling, applying, disposing modern MMVF may be underestimated as the conventional regulatory classification -combining composition, in-vivo clearance and effects- seems to be based entirely on MMVF after removal of the binder. Here we report the oxide composition of 23 modern MMVF from Germany, Finland, UK, Denmark, Russia, China (five different producers) and one pre-1995 MMVF. We find that most of the investigated modern MMVF can be classified as "High-alumina, low-silica wool", but several were on or beyond the borderline to "pre-1995 Rock (Stone) wool". We then used well-established flow-through dissolution testing at pH 4.5 and pH 7.4, with and without binder, at various flow rates, to screen the biosolubility of 14 MMVF over 32 days. At the flow rate and acidic pH of reports that found 47 ng/cm 2 /h dissolution rate for reference biopersistent MMVF21 (without binder), we find rates from 17 to 90 ng/cm 2 /h for modern MMVF as customary in trade (with binder). Removing the binder accelerates the dissolution significantly, but not to the level of reference biosoluble MMVF34. We finally simulated handling or disposing of MMVF and measured size fractions in the aerosol. The respirable fraction of modern MMVF is low, but not less than pre-1995 MMVF. The average composition of modern stone wool MMVF is different from historic biopersistent MMVF, but to a lesser extent than expected. The dissolution rates measured by abiotic methods indicate that the binder has a significant influence on dissolution via gel formation. Considering the content of respirable fibres, these findings imply that the risk assessment of modern stone wool may need to be revisited based on in-vivo studies of MMFV as marketed (with binder).

How practical is the application of percutaneous nephrolithotomy scoring systems? Prospective study comparing Guy's Stone Score, S.T.O.N.E. score and the Clinical Research Office of the Endourological Society (CROES) nomogram.

PubMed

Singla, Anurag; Khattar, Nikhil; Nayyar, Rishi; Mehra, Shibani; Goel, Hemant; Sood, Rajeev

2017-03-01

To prospectively compare the Guy's Stone Score (GSS), S.T.O.N.E. [stone size (S), tract length (T), obstruction (O), number of involved calices (N), and essence or stone density (E)] score and the Clinical Research Office of the Endourological Society (CROES) nephrolithometric nomogram to predict percutaneous nephrolithotomy (PCNL) success rate and assess the correlation with perioperative complications. We prospectively evaluated all consecutive PCNL patients at our institute between 1 November 2013 and 31 May 2015. The above scoring systems were applied to preoperative non-contrast computed tomography and the practical difficulties in such applications were noted. Perioperative complications and the stone-free rate (SFR) were also recorded. Receiver operating characteristic curves were drawn and the areas under curves were compared and appropriate statistical analysis done. In all, 48 renal units were included in the study. The overall SFR was 62.2%. The presence of staghorn stones ( β  = 27.285, 95% confidence interval 1.19-625.35; P  = 0.039) was the only significant variable associated with the residual stones on multivariate analysis. Stone-free patients had significantly lower median GSS (2 vs 4) and S.T.O.N.E. scores (6 vs 10) and higher median CROES scores (83% vs 63%) (all P  < 0.001) compared to residual-stone patients. All scoring systems were significantly associated with SFR (all P  < 0.001). There was no significant difference in the areas under curves of the scoring systems (0.858, 0.923, and 0.931, respectively). Furthermore, all scoring systems had weak correlations with Clavien-Dindo classified complications ( r  = 0.29, P  = 0.045; r  = 0.40, P  = 0.005 and r  = -0.295, P  = 0.04, respectively). We found no standardisation for the measurement of stone dimensions, tract length, Hounsfield units, and staghorn definition. All scoring systems equally predicted SFR and had a weak correlation with Clavien-Dindo complications. Standardisation is needed for the variables in which they have been found deficient.

In vitro investigations of propulsion during laser lithotripsy using video tracking.

PubMed

Eisel, Maximilian; Ströbl, Stephan; Pongratz, Thomas; Strittmatter, Frank; Sroka, Ronald

2018-04-01

Ureteroscopic laser lithotripsy is an important and widely used method for destroying ureter stones. It represents an alternative to ultrasonic and pneumatic lithotripsy techniques. Although these techniques have been thoroughly investigated, the influence of some physical parameters that may be relevant to further improve the treatment results is not fully understood. One crucial topic is the propulsive stone movement induced by the applied laser pulses. To simplify and speed up the optimization of laser parameters in this regard, a video tracking method was developed in connection with a vertical column setup that allows recording and subsequently analyzing the propulsive stone movement in dependence of different laser parameters in a particularly convenient and fast manner. Pulsed laser light was applied from below to a cubic BegoStone phantom loosely guided within a vertical column setup. The video tracking method uses an algorithm to determine the vertical stone position in each frame of the recorded scene. The time-dependence of the vertical stone position is characterized by an irregular series of peaks. By analyzing the slopes of the peaks in this signal it was possible to determine the mean upward stone velocity for a whole pulse train and to compare it for different laser settings. For a proof of principle of the video tracking method, a specific pulse energy setting (1 J/pulse) was used in combination with three different pulse durations: short pulse (0.3 ms), medium pulse (0.6 ms), and long pulse (1.0 ms). The three pulse durations were compared in terms of their influence on the propulsive stone movement in terms of upward velocity. Furthermore, the propulsions induced by two different pulse energy settings (0.8 J/pulse and 1.2 J/pulse) for a fixed pulse duration (0.3 ms) were compared. A pulse repetition rate of 10 Hz was chosen for all experiments, and for each laser setting, the experiment was repeated on 15 different freshly prepared stones. The latter set of experiments was compared with the results of previous propulsion measurements performed with a pendulum setup. For a fixed pulse energy (1 J/pulse), the mean upward propulsion velocity increased (from 120.0 to 154.9 mm · s -1 ) with decreasing pulse duration. For fixed pulse duration (0.3 ms), the mean upward propulsion velocity increased (from 91.9 to 123.3 mm · s -1 ) with increasing pulse energy (0.8 J/pulse and 1.2 J/pulse). The latter result corresponds roughly to the one obtained with the pendulum setup (increase from 61 to 105 mm · s -1 ). While the mean propulsion velocities for the two different pulse energies were found to differ significantly (P < 0.001) for the two experimental and analysis methods, the standard deviations of the measured mean propulsion velocities were considerably smaller in case of the vertical column method with video tracking (12% and 15% for n = 15 freshly prepared stones) than in case of the pendulum method (26% and 41% for n = 50 freshly prepared stones), in spite of the considerably smaller number of experiment repetitions ("sample size") in the first case. The proposed vertical column method with video tracking appears advantageous compared to the pendulum method in terms of the statistical significance of the obtained results. This may partly be understood by the fact that the entire motion of the stones contributes to the data analysis, rather than just their maximum distance from the initial position. The key difference is, however, that the pendulum method involves only one single laser pulse in each experiment run, which renders this method rather tedious to perform. Furthermore, the video tracking method appears much better suited to model a clinical lithotripsy intervention that utilizes longer series of laser pulses at higher repetition rates. The proposed video tracking method can conveniently and quickly deliver results for a large number of laser pulses that can easily be averaged. An optimization of laser settings to achieve minimal propulsive stone movement should thus be more easily feasible with the video tracking method in connection with the vertical column setup. Lasers Surg. Med. 50:333-339, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Mineral resource of the month: dimension stone

USGS Publications Warehouse

Dolley, Thomas P.

2012-01-01

The article offers information on dimension stone (DS) that are quarried as natural rock for a specific size and dimension chosen for its color, strength, durability. Varieties of metamorphic, igneous or sedimentary rocks are used but DS rocks are mainly marble, granite and slate that can be found from Maine to Alabama in the U.S., in the Carrara District of Italy as well as in Greece, China and Brazil. It also notes the advent of steel and concrete in construction that ceased the use of DS.

Self-Fluid Management in Prevention of Kidney Stones: A PRISMA-Compliant Systematic Review and Dose-Response Meta-Analysis of Observational Studies.

PubMed

Xu, Chang; Zhang, Chao; Wang, Xiao-Long; Liu, Tong-Zu; Zeng, Xian-Tao; Li, Shen; Duan, Xiao-Wen

2015-07-01

Epidemiologic studies have suggested that daily fluid intake that achieves at least 2.5 L of urine output per day is protective against kidney stones. However, the precise quantitative nature of the association between fluid intake and kidney stone risk, as well as the effect of specific types of fluids on such risk, are not entirely clear.We conducted a systematic review and dose-response meta-analysis to quantitatively assess the association between fluid intake and kidney stone risk. Based on a literature search of the PubMed, Embase, and Cochrane Library databases, 15 relevant studies (10 cohort and 5 case-control studies) were selected for inclusion in the meta-analysis with 9601 cases and 351,081 total participants.In the dose-response meta-analysis, we found that each 500 mL increase in water intake was associated with a significantly reduced risk of kidney stone formation (relative risk (RR) = 0.93; 95% CI: 0.87, 0.98; P < 0.01). Protective associations were also found for an increasing intake of tea (RR = 0.96; 95% CI: 0.93, 0.99; P = 0.02) and alcohol (RR = 0.80, 95% CI: 0.75, 0.85; P < 0.01). A borderline reverse association were observed on coffee intake and risk of kidney stone (RR = 0.88; 95% CI: 0.76, 1.00; P = 0.05). The risk of kidney stones was not significantly related to intake of juice (RR = 1.02, 95% CI: 0.95, 1.10; P = 0.64), soda (RR = 1.03; 95% CI: 0.90, 1.17; P = 0.65), or milk (RR = 0.96; 95% CI: 0.88, 1.03; P = 0.21). Subgroup analysis and sensitivity analyses showed inconsistent results on coffee, alcohol, and milk intake.Increased water intake is associated with a reduced risk of kidney stones; increased consumption of tea and alcohol may reduce kidney stone risk. An average daily water intake was recommended for kidney stone prevention.

Self-Fluid Management in Prevention of Kidney Stones: A PRISMA-Compliant Systematic Review and Dose–Response Meta-Analysis of Observational Studies

PubMed Central

Xu, Chang; Zhang, Chao; Wang, Xiao-Long; Liu, Tong-Zu; Zeng, Xian-Tao; Li, Shen; Duan, Xiao-Wen

2015-01-01

Abstract Epidemiologic studies have suggested that daily fluid intake that achieves at least 2.5 L of urine output per day is protective against kidney stones. However, the precise quantitative nature of the association between fluid intake and kidney stone risk, as well as the effect of specific types of fluids on such risk, are not entirely clear. We conducted a systematic review and dose–response meta-analysis to quantitatively assess the association between fluid intake and kidney stone risk. Based on a literature search of the PubMed, Embase, and Cochrane Library databases, 15 relevant studies (10 cohort and 5 case–control studies) were selected for inclusion in the meta-analysis with 9601 cases and 351,081 total participants. In the dose–response meta-analysis, we found that each 500 mL increase in water intake was associated with a significantly reduced risk of kidney stone formation (relative risk (RR) = 0.93; 95% CI: 0.87, 0.98; P < 0.01). Protective associations were also found for an increasing intake of tea (RR = 0.96; 95% CI: 0.93, 0.99; P = 0.02) and alcohol (RR = 0.80, 95% CI: 0.75, 0.85; P < 0.01). A borderline reverse association were observed on coffee intake and risk of kidney stone (RR = 0.88; 95% CI: 0.76, 1.00; P = 0.05). The risk of kidney stones was not significantly related to intake of juice (RR = 1.02, 95% CI: 0.95, 1.10; P = 0.64), soda (RR = 1.03; 95% CI: 0.90, 1.17; P = 0.65), or milk (RR = 0.96; 95% CI: 0.88, 1.03; P = 0.21). Subgroup analysis and sensitivity analyses showed inconsistent results on coffee, alcohol, and milk intake. Increased water intake is associated with a reduced risk of kidney stones; increased consumption of tea and alcohol may reduce kidney stone risk. An average daily water intake was recommended for kidney stone prevention. PMID:26166074

Using percutaneous transhepatic cholangioscopic lithotripsy for intrahepatic calculus in hostile abdomen.

PubMed

Kow, A W C; Wang, B; Wong, D; Sundeep, P J; Chan, C Y; Ho, C K; Liau, K H

2011-04-01

Hepatolithiasis is a challenging condition to treat especially in patients with previous hepatobiliary surgery. Percutaneous Transhepatic Cholangioscopic Lithotripsy (PTCSL) is an attractive salvage option for the treatment of recurrent hepatolithiasis. We reviewed our experience using PTCSL in treating 4 patients with previous complex abdominal surgery. We studied the 4 patients who underwent PTCSL from October 2007 to July 2009. We reviewed the operative procedures, workflow of performing PTCSL in our institution and the outcome of the procedure. PTCSL was performed in our institution using 3 mm cholangioscope (Dornier MedTech(®)) and Holmium laser with setting at 0.8 J, 20 Hz and 16 W. This was performed through a Percutaneous Transhepatic Cholangio-catheter inserted by interventional radiologists. There were 4 patients with a median age of 50 (43-69) years. The median duration of the condition prior to PTCSL was 102 (60-156) months. Three patients had recurrent pyogenic cholangitis (RPC) with recurrent intrahepatic stone. They all had prior complex hepatobiliary operations. The median duration of surgery was 130 (125-180) min. There was minimal intra-operative blood loss. The first procedure was performed under local anaesthesia and sedation, however, with experience the subsequent 3 patients had the procedure performed under general anaesthesia. The median size of bile duct was 18 (15-20) mm prior to the procedure. The number of stones ranged from one to three with the largest size of stone comparable to the size of bile duct. The median follow up was 18 (10-24) months. All patients were symptom free with neither stone recurrence or cholangitis at the last follow up. PTCSL is a feasible and an effective treatment method for patients with recurrent biliary stone following complex abdominal surgery as the success rates from open surgery and endoscopic procedures are limited. Excellent results can be expected with this minimally invasive technique. Copyright © 2010 Royal College of Surgeons of Edinburgh (Scottish charity number SC005317) and Royal College of Surgeons in Ireland. Published by Elsevier Ltd. All rights reserved.

Implementation of Ultramini Percutaneous Nephrolithotomy for Treatment of 2-3 cm Kidney Stones: A Preliminary Report.

PubMed

Shah, Arvind K; Xu, Kewei; Liu, Hao; Huang, Hai; Lin, Tianxin; Bi, Liangkuan; Jinli, Han; Fan, Xinxiang; Shrestha, Rujan; Huang, Jian

2015-11-01

Miniatured percutaneous nephrolithotomy (PCNL) techniques such as micro-PCNL (microperc) and ultramini-PCNL (UMP) are usually indicated for renal stones <2 cm. We present our preliminary report of treating patients with 2 to 3 cm renal stones using UMP in a semisupine combined lithotomy position associated with a retrograde ureteral access sheath (UAS). From April 2013 to January 2014, we implemented 13F UMP for 22 patients with renal stones that were 2 to 3 cm with the patient positioned in a 45-degree semisupine combined lithotomy position. A retrograde 9.5/11.5F UAS was placed for maintaining low intrarenal pressure and debris drainage. Flexible ureteroscopy was used for stones inaccessible through the primary percutaneous tract in two patients. A 200-μ holmium laser was used for stone disintegration. Intrapelvic pressure was measured using an open end 5F ureteral catheter inserted through the UAS. All 22 cases were completed successfully. The mean preoperative stone size was 26.6 ± 4.7 mm (range 21-32 mm), mean operative time was 85.7 ± 18.0 minutes (range 47-112 min), and mean hemoglobin drop was 1.2 ± 0.3 g/dL (range 0.5-2.2 g/dL). Intrapelvic pressure during the surgical procedure ranged 5 to 10 cm H2O. The mean hospital stay was 3.1 ± 1.8 days (range 2-5 d). Complete stone clearance was 18/22 (81.8%) with solo UMP and 20/22 (90.9%) when associated with retrograde intrarenal surgery (RIRS). No major intra- or postoperative complications occurred. Implementation of UMP for the treatment of patients with renal stones 2-3 cm is feasible and safe. The procedure is less invasive and has a faster recovery period. Intraoperative retrograde UAS decreases intrarenal pressure, facilitates removal of stone fragments, and also allows simultaneous RIRS for stones in an inaccessible calix.

Efficacy of nifedipine and alfuzosin in the management of distal ureteric stones: A randomized, controlled study

PubMed Central

Sameer; Lal, Shyam; Charak, K. S.; Chakravarti, Sumit; Kohli, Supreeti; Ahmad, Shamshad

2014-01-01

Introduction: Stone disease is a significant and world-wide health problem. Recently, certain drugs have been used as a supplement to observation alone in an effort to improve spontaneous stone expulsion. We evaluated the efficacy of nifedipine and alfuzosin in the medical treatment of symptomatic, uncomplicated distal ureteral stones. Materials and Methods: This was a randomized controlled prospective study to determine the efficacy of alfuzosin and nifedipine as an adjunctive medical therapy, to increases the stone-expulsion rates in distal ureteric calculus of size ≤10 mm. Investigators and patients were blinded to the randomization scheme. Patients were randomly divided into three equal groups of 35 patients each. Patients in Group I received tablet nifedipine 30 mg/day, Group II received alfuzosin 10 mg/day and Group III was the control group received tablet diclofenac sodium. The patient blood pressure, stone position on imaging, number of pain attacks, time of stone-expulsion, hospital re-admission and any adverse events were assessed. Patients were followed-up weekly and continued until the patient was rendered stone free or up to 28 days. Statistical analysis was performed and P < 0.05 was considered to be significant. Results: Stone-expulsion was observed in 60%, 85.7% and 20% patients in Group I, II and III respectively. A statistically significant difference was noted in between Groups I versus III, Groups II versus III and Groups I versus II (P < 0.0001, P < 0.0001, and P < 0.0315 respectively). The mean number of pain attacks was 2.91 ± 1.01 for Group I, 1.8 ± 0.83 for Group II, and 2.82 ± 1.12 for Group III, which is statistical significant in Groups II versus III, and Groups I versus II (P < 0.001 and P < 0.001). Hospital re-admission rate was less in treatment groups when compare to control group (P < 0.0001). Conclusion: The use of alfuzosin and nifedipine as a medical expulsive therapy for distal ureteric stones proved to be safe and effective in term of increased stone-expulsion rate, reduced pain attacks and decrease hospital re-admissions. PMID:25378819

Treatment Using the SpyGlass Digital System in a Patient with Hepatolithiasis after a Whipple Procedure.

PubMed

Harima, Hirofumi; Hamabe, Kouichi; Hisano, Fusako; Matsuzaki, Yuko; Itoh, Tadahiko; Sanuki, Kazutoshi; Sakaida, Isao

2018-05-23

An 89-year-old man was referred to our hospital for treatment of hepatolithiasis causing recurrent cholangitis. He had undergone a prior Whipple procedure. Computed tomography demonstrated left-sided hepatolithiasis. First, we conducted peroral direct cholangioscopy (PDCS) using an ultraslim endoscope. Although PDCS was successfully conducted, it was unsuccessful in removing all the stones. The stones located in the B2 segment were difficult to remove because the endoscope could not be inserted deeply into this segment due to the small size of the intrahepatic bile duct. Next, we substituted the endoscope with an upper gastrointestinal endoscope. After positioning the endoscope, the SpyGlass digital system (SPY-DS) was successfully inserted deep into the B2 segment. Upon visualizing the residual stones, we conducted SPY-DS-guided electrohydraulic lithotripsy. The stones were disintegrated and completely removed. In cases of PDCS failure, a treatment strategy using the SPY-DS can be considered for patients with hepatolithiasis after a Whipple procedure.

Influence of porosity on artificial deterioration of marble and limestone by heating

NASA Astrophysics Data System (ADS)

Sassoni, Enrico; Franzoni, Elisa

2014-06-01

Testing of stone consolidants to be used on-site, as well as research on new consolidating products, requires suitable stone samples, with deteriorated but still uniform and controllable characteristics. Therefore, a new methodology to artificially deteriorate stone samples by heating, exploiting the anisotropic thermal deformation of calcite crystals, has recently been proposed. In this study, the heating effects on a variety of lithotypes was evaluated and the influence of porosity in determining the actual heating effectiveness was specifically investigated. One marble and four limestones, having comparable calcite amounts but very different porosity, were heated at 400 °C for 1 hour. A systematic comparison between porosity, pore size distribution, water absorption, sorptivity and ultrasonic pulse velocity of unheated and heated samples was performed. The results of the study show that the initial stone porosity plays a very important role, as the modifications in microstructural, physical and mechanical properties are way less pronounced for increasing porosity. Heating was thus confirmed as a very promising artificial deterioration method, whose effectiveness in producing alterations that suitably resemble those actually experienced in the field depends on the initial porosity of the stone to be treated.

Flexible ureterorenoscopy in position or fusion anomaly: Is it feasible?

PubMed

Astolfi, Rafael Haddad; Freschi, Gustavo; Berti, Fernando Figueiredo; Gattas, Nelson; Molina, Wilson Rica; Meller, Alex

2017-08-01

To analyze the results of flexible ureterorenoscopy (F-URS) with holmium laser in the treatment of kidney stones with ectopic and fusion anomalies (horseshoe kidney and rotation anomalies). We reviewed data from 13 patients with fusion and ectopic renal anomalies that underwent F-URS from April 2011 to April 2017. We analyzed demographic and clinical data (age, gender, BMI, anatomical abnormality, location and dimension of the renal calculi) and perioperative data (method of treatment, stone-free rate, number of days with DJ catheter and perioperative complications). The mean stone size was 12.23 +/- 5.43 mm (range 6-22mm), located in the inferior (58.33%) and middle (16.76%) calyceal units, renal pelvis (16.67%) and multiple locations (8.33%). All 13 patients were treated with Ho-Yag laser, using dusting technique (25%), fragmentation and extraction of the calculi (58.33%) and mixed technique (16.67%). We did not have any severe perioperative complication. After 90 days, nine patients (75%) were considered stone free. Our data suggest that F-URS is a safe and feasible choice for the treatment of kidney stones in patients with renal ectopic and fusion anomalies.

Single-center North American experience with wolf Piezolith 3000 in management of urinary calculi.

PubMed

Wang, Rou; Faerber, Gary J; Roberts, William W; Morris, David S; Wolf, J Stuart

2009-05-01

To review our experience with the newest generation piezoelectric lithotripter, the Piezolith 3000, in adult patients undergoing extracorporeal shock wave lithotripsy for solitary urinary calculi. We identified 139 shock wave lithotripsy procedures that had used the Piezolith 3000 from February 2005 to July 2007. All procedures were performed under intravenous sedation. Retrospective chart review was used to obtain the pertinent information. Stone-free status was defined as the absence of any fragments, and success as the absence of stone fragments >4 mm, on follow-up imaging after a single treatment. The stone-free and success rate 1 month after a single shock wave lithotripsy session was 45% and 64%, respectively. Only stone size correlated with the overall success rate (P = .004). The overall complication rate was 15% and included a 5.8% major complication rate requiring intervention or admission. The median time in the procedure room was 33 minutes. The adjunctive procedure rate was 1.4%, and the secondary retreatment rate was 10%. The Piezolith 3000 provides modest, but acceptable, single-treatment stone-free and success rates, with a reasonable safety profile, and offers rapid and convenient lithotripsy requiring only intravenous sedation.

Level II scour analysis for Bridge 17 (NEWHTH00200017) on Town Highway 20, crossing Little Otter Creek, New Haven, Vermont

USGS Publications Warehouse

Wild, Emily C.; Burns, Ronda L.

1998-01-01

This report provides the results of a detailed Level II analysis of scour potential at structure NEWHTH00200017 on Town Highway 20 crossing Little Otter Creek, New Haven, Vermont (figures 1–8). A Level II study is a basic engineering analysis of the site, including a quantitative analysis of stream stability and scour (U.S. Department of Transportation, 1993). Results of a Level I scour investigation also are included in appendix E of this report. A Level I investigation provides a qualitative geomorphic characterization of the study site. Information on the bridge, gleaned from Vermont Agency of Transportation (VTAOT) files, was compiled prior to conducting Level I and Level II analyses and is found in appendix D. The site is in the Champlain section of the St. Lawrence Valley physiographic province in west-central Vermont. The 10.8-mi2 drainage area is in a predominantly rural and wetland basin. In the vicinity of the study site, the surface cover is shrubland on the downstream right overbank. The surface cover of the downstream left overbank, the upstream right overbank and the upstream left overbank is wetland and pasture. In the study area, Little Otter Creek has a meandering channel with a slope of approximately 0.0007 ft/ft, an average channel top width of 97 ft and an average bank height of 5 ft. The channel bed material ranges from silt and clay to cobble. Medium sized silt and clay is the channel material upstream of the approach cross-section and downstream of the exit cross-section. The median grain size (D50) of the silt and clay channel bed material is 1.52 mm (0.005 ft), which was used for contraction and abutment scour computations. From the approach cross-section, under the bridge, and to the exit cross-section, stone fill is the channel bed material. The median grain size (D50) of the stone fill channel bed material is 95.7 mm (0.314 ft). The stone fill median grain size was used solely for armoring computations. The geomorphic assessment at the time of the Level I and Level II site visit on June 11, 1996, indicated that the reach was stable.The Town Highway 20 crossing of Little Otter Creek is a 32-ft-long, two-lane bridge consisting of a 28-ft steel-beam span (Vermont Agency of Transportation, written communication, December 15, 1995). The opening length of the structure parallel to the bridge face is 24.9 ft. The bridge is supported by almost vertical, concrete abutments. The channel is skewed approximately 15 degrees to the opening while the opening-skew-toroadway is zero degrees. The scour countermeasures at the site consisted of type-1 stone fill (less than 12 inches diameter) along the left and right abutments, as well as along the upstream left and right banks. Type-2 stone fill (less than 36 inches diameter) was present along the downstream right bank. Additional details describing conditions at the site are included in the Level II Summary and appendices D and E. Scour depths and recommended rock rip-rap sizes were computed using the general guidelines described in Hydraulic Engineering Circular 18 (Richardson and Davis, 1995) for the 100- and 500-year discharges. In addition, the incipient roadway-overtopping discharge was determined and analyzed as another potential worst-case scour scenario. Total scour at a highway crossing is comprised of three components: 1) long-term streambed degradation; 2) contraction scour (due to accelerated flow caused by a reduction in flow area at a bridge) and; 3) local scour (caused by accelerated flow around piers and abutments). Total scour is the sum of the three components. Equations are available to compute depths for contraction and local scour and a summary of the results of these computations follows. Contraction scour for all modelled flows ranged from 9.7 to 13.8 ft. The worst-case contraction scour occurred at the 500-year discharge. Left abutment scour ranged from 6.9 to 7.9 ft. Right abutment scour ranged from 10.5 to 11.8 ft. The worst-case left and right abutment scour occurred at the 500-year discharge. Additional information on scour depths and depths to armoring are included in the section titled “Scour Results”. Scoured-streambed elevations, based on the calculated scour depths, are presented in tables 1 and 2. A cross-section of the scour computed at the bridge is presented in figure 8. Scour depths were calculated assuming an infinite depth of erosive material and a homogeneous particle-size distribution. It is generally accepted that the Froehlich equation (abutment scour) gives “excessively conservative estimates of scour depths” (Richardson and Davis, 1995, p. 47). Usually, computed scour depths are evaluated in combination with other information including (but not limited to) historical performance during flood events, the geomorphic stability assessment, existing scour protection measures, and the results of the hydraulic analyses. Therefore, scour depths adopted by VTAOT may differ from the computed values documented herein.

Emergency extracorporeal shockwave lithotripsy for acute renal colic caused by upper urinary-tract stones.

PubMed

Kravchick, Sergey; Bunkin, Igor; Stepnov, Eugeny; Peled, Ronit; Agulansky, Leonid; Cytron, Shmuel

2005-01-01

To evaluate emergency SWL for the treatment of upper urinary-tract stones causing renal colic. Between January 1999 and June 2003, 53 patients with a mean age of 46.6 years (range 22-65 years) were enrolled. The inclusion criteria were acute renal colic, radiopaque 5-mm to 1.5-cm calculi in the ureteropelvic junction (N=10) or upper ureter (N=43), and no evidence of urinary-tract infection or acute renal failure. The mean stone size was 7.14 mm (range 5-13 mm). Patients were randomly assigned to the control (N=28) and study (N=25) groups using previously prepared cards in envelopes. Patients in the study group underwent emergency SWL, while patients in the control group underwent scheduled SWL within 30 days. Stone status was evaluated 4 weeks after lithotripsy. There was no significant difference between the control and study groups with respect to age, sex, stone location or volume, renal obstruction, or days spent in the hospital for pain control. Available fragments of stones were sent for infrared spectroscopy. Preoperative and postoperative data were compared in the two groups using SPSS 10.0 statistical software. The SWL treatment lasted 50+/-11 minutes. The stone-free rates were 72% and 64% and the efficiency quotients were 53% and 44% in study and control groups, respectively. Patients in the control group spent more time in the hospital (P=0.014) and in recovery at home (P=0.011). Emergency SWL for acute renal colic caused by upper-ureteral stones is a safe procedure and offers effective release from pain and obstruction. It also decreases hospitalization days and hastens return to normal activity.

Comparative study of laparoscopic pyelolithotomy versus percutaneous nephrolithotomy in the management of large renal pelvic stones

PubMed Central

Haggag, Yasser M.; Morsy, Gamal; Badr, Magdy M.; Al Emam, Abdel Baset A.; Farid, Mourad; Etafy, Mohamed

2013-01-01

Background The aim of the study is to investigate whether laparoscopic pyelolithotomy (LPL) could be used to manage large renal pelvic stones, generally considered excellent indications for percutaneous nephrolithotomy (PNL). Methods: This study was performed from May 2009 to March 2012 at Al-Azhar University Hospitals (Assiut and Cairo), Egypt. It included two groups of patients with large renal pelvic stones; only patients with stones 2.5 cm2 or greater were included. Group 1 included 40 patients treated by PNL and Group 2 included 10 patients treated by LPL. The differences between the two procedures were compared and analyzed. Results: There was no difference between the two groups regarding patient demographics and stone size. There was a statistically significant difference between the groups regarding mean estimated blood loss (65 ± 12.25 [range: 52.75–77.25] vs. 180 ± 20.74 [range: 159.26–200.74] mL, p ≤ 0001), mean hospital stay (2.3 ± 0.64 [range: 1.66–2.94] vs. 3.7 ± 1.4 [range: 2.3–5.1] days, p ≤ 0.006), rate of postoperative blood transfusion (0% vs. 4.8%, p ≤ 0.0024), and stone-free rate (80% vs. 78.6%, p ≤ 0.23). The mean operative time was significantly longer in Group 2 (LPL) (131 ± 22.11 [range: 108.89–153.11) vs. 51.19 ± 24.39 [range: 26.8–75.58] min, p ≤ 0001), respectively. Conclusion: Although PNL is the standard treatment in most cases of renal pelvic stones, LPL is another feasible surgical technique for patients with large renal pelvic stones. PMID:23589752

The Influence of Body Mass Index on Outcomes in Ureteroscopy: Results from the Clinical Research Office of Endourological Society URS Global Study.

PubMed

Krambeck, Amy; Wijnstok, Nienke; Olbert, Peter; Mitroi, George; Bariol, Simon; Shah, Hemendra N; El-Abd, Ahmed S; Onal, Bulent; de la Rosette, Jean

2017-01-01

Although ureteroscopy (URS) has been established as a viable treatment for stones in obese patients, its safety and success has not been fully elucidated. The current study describes the worldwide prevalence of obesity in patients with urolithiasis and examines trends in URS outcomes, safety, and efficacy. This study utilized the Clinical Research Office of the Endourological Society (CROES) URS Global Study, which was a prospective, multicenter study including 11,885 patients treated with URS for urinary stones at 1 of 114 urology departments across 32 countries. The relationship between body mass index (BMI), diabetes, and creatinine, with retreatment, stone-free rates, complications, and long hospital stay, was examined with a multivariate logistic regression analyses. Of the 10,099 URS patients with BMI data, 17.4% were obese and 2.2% were super obese. Overall, 86.7% patients were stone free and 16.8% required retreatment. Higher BMI was associated with lower stone-free rates, and any deviation from normal weight was associated with higher retreatment rates. In multivariate analysis controlling for several variables including stone size, the association between BMI and lower stone-free rates with higher retreatment rates persisted. Intraoperative complications occurred in 518 (5.1%) patients, and 343 (3.4%) experienced a postoperative complication. Postoperative complications were more frequent in the underweight and super obese subjects, and there was no relationship between BMI and intraoperative complications. Although URS for stone disease was found to be an overall safe procedure for obese and super obese patients, efficacy of the procedure may be lower compared with normal-weight subjects and higher retreatment rates may be necessary.

Use of magnetic resonance cholangiography in the diagnosis of choledocholithiasis: prospective comparison with a reference imaging method

PubMed Central

Zidi, S; Prat, F; Le Guen, O; Rondeau, Y; Rocher, L; Fritsch, J; Choury, A; Pelletier, G

1999-01-01

Background—Magnetic resonance cholangiography (MRC) is a new technique for non-invasive imaging of the biliary tract. 
Aim—To assess the results of MRC in patients with suspected bile duct stones as compared with those obtained with reference imaging methods. 
Patients/Methods—70 patients (34 men and 36 women, mean (SD) age 71 (15.5) years; median 75) with suspected bile duct stones were included (cholangitis, 33; pancreatitis, three; suspected post-cholecystectomy choledocholithiasis, nine; cholestasis, six; stones suspected on ultrasound or computed tomography scan, 19). MR cholangiograms with two dimensional turbo spin echo sequences were acquired. Endoscopic retrograde cholangiography with or without sphincterotomy (n = 63), endosonography (n = 5), or intraoperative cho- langiography (n = 2) were the reference imaging techniques used for the study and were performed within 12 hours of MRC. Radiologists were blinded to the results of endoscopic retrograde cholangiography and previous investigations. 
Results—49 patients (70%) had bile duct stones on reference imaging (common bile duct, 44, six of which impacted in the papilla; intrahepatic, four; cystic duct stump, one). Stone size ranged from 1 to 20 mm (mean 6.1, median 5.5). Twenty seven patients (55%) had bile duct stones smaller than 6 mm. MRC diagnostic accuracy for bile duct lithiasis was: sensitivity, 57.1%; specificity, 100%; positive predictive value, 100%; negative predictive value, 50%. 
Conclusions—Stones smaller than 6 mm are still often missed by MRC when standard equipment is used. The general introduction of new technical improvements is needed before this method can be considered reliable for the diagnosis of bile duct stones. 

 Keywords: bile duct calculi; endoscopic retrograde cholangiography; magnetic resonance cholangiography PMID:9862837

Correlation between microstructural characteristics and weight loss of natural stones exposed to simulated acid rain.

PubMed

Franzoni, Elisa; Sassoni, Enrico

2011-12-15

The correlation between stone microstructural characteristics and material degradation (in terms of weight loss), in given environmental conditions, was investigated. Seven lithotypes, having very different microstructural characteristics, were used. Four acidic aqueous solutions were prepared to simulate acid rain (two adding H(2)SO(4) and two adding HNO(3) to deionized water, in order to reach, for each acid, pH values of 5.0 and 4.0), and deionized water at pH=5.6 was used to simulate clean rain. Stone samples were then immersed in such aqueous solutions, the surface alteration being periodically inspected and the weight loss periodically measured. After 14 days of immersion, a good correlation was found between weight loss and the product of carbonate content and specific surface area in the starting materials. This was explained considering that this product accounts for the weight loss owing to the sample's fraction actually composed of calcite (the most soluble fraction) and the effective surface area exposed to dissolving solution (which depends on stone porosity and pore size distribution). Such correlation between stone microstructure and degradation may be useful for comparing the durability of different lithotypes, in given environmental conditions, and quantitatively predicting the weight loss of a lithotype, compared to another one. Hence, the correlation found in this study may be used to specifically tailor to various stone types, with different microstructural characteristics, some results that have been calculated in literature for specific stone types and then proposed as possibly representative for a broad category of stones with similar characteristics. Copyright © 2011 Elsevier B.V. All rights reserved.

Safety and feasibility of day case ureteroscopy and laser lithotripsy (URSL) in patients with a solitary kidney

PubMed Central

Ghosh, Anngona

2016-01-01

Introduction The management of nephrolithiasis in patients with a solitary kidney poses a treatment challenge. The study aimed to evaluate the outcomes of ureteroscopy and laser stone fragmentation (URSL) for renal stones in these patients treated in our university teaching hospital. Material and methods Between July 2012 and December 2014, seventeen cases of URSL for stones in a solitary kidney were reviewed. Patient demographics, stone dimensions, perioperative and post-operative outcomes were recorded in a prospectively maintained database. Serum creatinine levels pre-procedure and at follow-up were also compared. Results Seventeen cases of URSL were conducted with a mean age of 52.9 ±19.9 years. 8 of the 17 (47%) patients had stones in multiple locations and 13 (76%) were in the lower pole. The mean ± SD stone size and BMI were 13.0 ±8.9 mm and 31.6 ±5.8 kg/m2, respectively. The stone free rate (SFR) was 82.5%. Fourteen (82.5%) patients were discharged the same day and 16 cases (94%) were discharged within 24 hours. For patients with deranged pre-operative serum creatinine, the mean serum creatinine level improved from 131.2 ±68.3 µmol/L pre-URSL to 106.5 ±36.7 µmol/L at follow-up. There was one Clavien grade II complication with a patient requiring additional antibiotics for post-operative urinary tract infection. There were no other major or minor complications. Conclusions Day case ureteroscopy for stone disease in a solitary kidney is safe and feasible with a low complication rate and an overall improvement in renal function. PMID:27123333

[A field experiment of runoff and sediment yielding processes from residues in Shenfu-Dongsheng Coalfield].

PubMed

Li, Jian-Ming; Wang, Wen-Long; Wang, Zhen; Luo, Ting; Li, Hong-Wei; Jin, Jian

2013-12-01

The processes of runoff and sediment yields from and the benefits of water and sediment reductions by the residues produced in the Shenfu-Dongsheng Coalfield were investigated by a simulated field rainfall experiment. The runoff generation time generally presented a decreasing trend with increasing rainfall intensity, but varied widely with the change of residue compositions. Runoff from the slag reached a steady velocity faster than that from the spoil, and the average velocities of runoff from the residues were gradually decreased in the spoil, the slag with more sand and less stone, and the slag with less sand and more stone. Runoff rates for the residues reached a steady rate 6 min after runoff generation, and were significantly correlated with the rainfall intensities. Erosion on the residues mainly occurred in the first 6 min after runoff generation. Average sediment concentrations in the first 6 min were 0.43-4.27 times of those thereafter for the spoil, and 1.43-54.93 times for the slag. The runoff volume was a linear function of the rainfall intensity for the spoil and the slag with more sand and less stone, and was a power function of rainfall intensity for the slag with less sand and more stone. The relationships between single erosion and rainfall intensity for the spoil and the slag with less sand and more stone can be described by exponential and power functions, respectively. For the spoil, the erosion rate was a linear function of the runoff volume. When fish-scale pits and vegetation coverage were adopted on the surface of the slag, the generation of runoff lagged 24 min behind initial rainfall applications at intensities of 1.0 and 1.5 mm x min(-1), and the runoff and sediment yields were reduced by 29.5%-52.9% and 85.7%-97.9%, respectively.

Thulium fiber laser lithotripsy using small spherical distal fiber tips

NASA Astrophysics Data System (ADS)

Wilson, Christopher R.; Hardy, Luke A.; Kennedy, Joshua D.; Irby, Pierce B.; Fried, Nathaniel M.

2016-02-01

This study tests a 100-μm-core fiber with 300-μm-diameter ball tip during Thulium fiber laser (TFL) lithotripsy. The TFL was operated at 1908 nm wavelength with 35-mJ pulse energy, 500-μs pulse duration, and 300-Hz pulse rate. Calcium oxalate/phosphate stone samples were weighed, laser procedure times measured, and ablation rates calculated for ball tip fibers, with comparison to bare tip fibers. Photographs of ball tips were taken before and after each procedure to observe ball tip degradation and determine number of procedures completed before need to replace fiber. Saline irrigation rates and ureteroscope deflection were measured with and without TFL fiber present. There was no statistical difference (P > 0.05) between stone ablation rates for single-use ball tip fiber (1.3 +/- 0.4 mg/s) (n=10), multiple-use ball tip fiber (1.3 +/- 0.5 mg/s) (n=44), and conventional single-use bare tip fibers (1.3 +/- 0.2 mg/s) (n=10). Ball tip durability varied widely, but fibers averaged > 4 stone procedures before decline in stone ablation rates due to mechanical damage at front surface of ball tip. The small fiber diameter did not impact ureteroscope deflection or saline flow rates. The miniature ball tip fiber may provide a cost-effective design for safe fiber insertion through the ureteroscope working channel and the ureter without risk of scope damage or tissue perforation, and without compromising stone ablation efficiency during TFL ablation of kidney stones.

Surface Charge-Transfer Doping of Graphene Nanoflakes Containing Double-Vacancy (5-8-5) and Stone-Wales (55-77) Defects through Molecular Adsorption.

PubMed

Shakourian-Fard, Mehdi; Jamshidi, Zahra; Kamath, Ganesh

2016-10-18

The adsorption of six electron donor-acceptor (D/A) organic molecules on various sizes of graphene nanoflakes (GNFs) containing two common defects, double-vacancy (5-8-5) and Stone-Wales (55-77), are investigated by means of ab initio DFT [M06-2X(-D3)/cc-pVDZ]. Different D/A molecules adsorb on a defect graphene (DG) surface with binding energies (ΔE b ) of about -12 to -28 kcal mol -1 . The ΔE b values for adsorption of molecules on the Stone-Wales GNF surface are higher than those on the double vacancy GNF surface. Moreover, binding energies increase by about 10 % with an increase in surface size. The nature of cooperative weak interactions is analyzed based on quantum theory of atoms in molecules, noncovalent interactions plot, and natural bond order analyses, and the dominant interaction is compared for different molecules. Electron density population analysis is used to explain the n- and p-type character of defect graphene nanoflakes (DGNFs) and also the change in electronic properties and reactivity parameters of DGNFs upon adsorption of different molecules and with increasing DGNF size. Results indicate that the HOMO-LUMO energy gap (E g ) of DGNFs decreases upon adsorption of molecules. However, by increasing the size of DGNFs, the E g and chemical hardness of all complexes decrease and the electrophilicity index increases. Furthermore, the values of the chemical potential of acceptor-DGNF complexes decrease with increasing size, whereas those of donor-DGNF complexes increase. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Trypsin level in gallbladder bile and ductitis and width of the cystic duct.

PubMed

Vracko, J; Wiechel, K L

2000-01-01

The change from laparotomy to laparoscopy for cholecystectomy has raised the question of how to manage concomitant bile duct stones. The present-day interest--and controversy--has focused on a transcystic approach reported to be feasible in 66-96% of cases, but without explaining the necessary prerequisite: the widening of the cystic duct. The cystic duct, wide mainly in patients with bile duct stones, has been reported to be highly variable: from strictured to very wide. The present study aims at comparing the trypsin level in the gallbladder bile and the cystic duct morphology and width in patients with and without bile duct stones. A prospective series of 63 gallstone patients, 30 with and 33 without bile duct stones (controls), underwent cholecystectomy and bile duct clearance. The study includes the trypsin level in the gallbladder bile, the width and morphology of the cystic duct, and the size of the gallstones. The patients with bile duct stones had, in contrast to the controls, higher trypsin levels in the gallbladder bile (P < 0.001) and wider cystic ducts (P < 0.001) with more pronounced signs of chronic ductitis. The obtained results strongly suggest that the increased trypsin level, a sign of reflux of pancreatic juice, caused changes in the cystic duct that facilitate gallstone migration, which also ought to render a transcystic stone extraction feasible.

Development of lithotripter technology

NASA Astrophysics Data System (ADS)

Eisenmenger, Wolfgang F. W.

2003-10-01

``Squeezing'' of the stone or cirumferential pressure of the wave propagating at the outside of the stone in the liquid or tissue results in fragmentation in planes perpendicular or parallel to the wave propagation direction. The corresponding pressure zone propagating with the sound velocity in the liquid which is below the sound velocity in the stone, causes an evanescent pressure zone in the stone resulting in tensile stress in planes parallel and perpendicular to the wave plane. A quantitative model predicting the ratio of pulses needed to fragment the stone to 2 mm particle size in relation to the number of pressure pulses needed for the first fragmentation is well in accord with experiments, supporting the ``squeezing mechanism with binary fragmentation.'' On the basis of these results it now appears possible to optimize the pressure pulse parameters measured using the Fiber Optic Probe Hydrophone (FOPH). With correspondingly optimized self-focusing electromagnetic shock wave generator systems a clinical study of the concept ``wide focus and low pressure'' ESWL was performed in a scientific cooperation between the 1. Physical Institute of the University of Stuttgart and the Xixin Medical Instruments Co., Ltd. in Suzhou, China. Literature: W. Eisenmenger, ``The mechanisms of stone fragmentation in ESWL,'' Ultrasound Med. Biol. 27, 683-693 (2001); W. Eisenmenger et al., ``The first clinical results of `wide focus and low pressure' ESWL,'' Ultrasound Med. Biol. 28, 769-774 (2002).

One year follow up of the outcomes of child patients with melamine-related kidney stones in Beijing and surrounding provinces in China.

PubMed

Shen, Ying; Sun, Qiang; Gao, Jie; Jia, Li-Qun; Sun, Ning; Pan, Yue-Song; Liu, Xiao-Mei; Liu, Xiao-Rong; Wang, Yu; Wu, Dong-Xue; Jiang, Ye-Ping

2011-05-01

To evaluate their prognosis, the damage by melamine on children's kidney and other organs, and its influence on the children's development, was investigated. Nine hundred and sixty-two Chinese children were divided into three groups: group A, 265 children diagnosed with melamine-associated urolithiasis; group B, 197 children with a history of melamine-contaminated milk powder consumption but without urolithiasis; and group C, 500 healthy children. They were examined at 0, 1, 3, 6 and 12 months. The factors influencing the prognosis were investigated. The stone discharge was monitored by ultrasonography. Overt renal and liver damage and underlying renal injury markers were analyzed. The stone discharge rates 1, 3, 6 and 12 months after the diagnoses were 52.5%, 67.2%, 88.3% and 95.5%, respectively. Stone size was a stable influencing factor for the stone discharge rate. Additionally, the values of the potential renal injury markers in children with stones already discharged is equivalent to normal children. This 12 month follow up of early renal injury markers indicated that the damage to the kidney is temporary with no persistent negative outcomes being found till now. Additionally, the gross development of the children seemed not yet jeopardized by melamine. Longer-term follow up will be conducted. © 2011 The Authors. Nephrology © 2011 Asian Pacific Society of Nephrology.

Synergism between urinary prothrombin fragment 1 and urine: a comparison of inhibitory activities in stone-prone and stone-free population groups.

PubMed

Webber, Dawn; Rodgers, Allen L; Sturrock, Edward D

2002-09-01

South African blacks rarely form kidney stones compared with whites. This study investigated whether purified urinary prothrombin fragment 1 (UPTF1) derived from blacks is a more potent inhibitor of calcium oxalate crystallisation than that from whites. UPTF1 was purified from the urine of both population groups and their inhibitory activities were compared in a cross-over design in which each protein was tested in ultrafiltered urine from both population groups. Coulter Multisizer, [14C]-oxalate deposition and scanning electron microscopy experiments were used to monitor crystallisation. The study has demonstrated for the first time that UPTF1 promotes nucleation and that inhibitory activity is synergistically dependent upon urine composition. The activity of the whites' UPTF1 was greater than that of the blacks in the whites' urine (e.g. particle size decrease: 31.7% vs. 25.2%), while the blacks' UPTF1 was superior to that of the whites in the blacks' urine (e.g. particle size decrease: 46.5% vs. 32.4%). In addition, when tested in their respective endogenous urines, the blacks' UPTF1 demonstrated superior inhibitory activity on an absolute scale (e.g. particle size decrease: 46.5% vs. 31.7%). Thus, the urine composition of black South Africans may influence their UPTF1 conformation, conferring greater efficacy for inhibition of calcium oxalate crystallisation.

Oxalate absorption and endogenous oxalate synthesis from ascorbate in calcium oxalate stone formers and non-stone formers.

PubMed

Chai, Weiwen; Liebman, Michael; Kynast-Gales, Susan; Massey, Linda

2004-12-01

Increased rates of either oxalate absorption or endogenous oxalate synthesis can contribute to hyperoxaluria, a primary risk factor for the formation of calcium oxalate-containing kidney stones. This study involves a comparative assessment of oxalate absorption and endogenous oxalate synthesis in subpopulations of stone formers (SFs) and non-stone formers (NSFs) and an assessment of the effect of ascorbate supplementation on oxalate absorption and endogenous oxalate synthesis. Twenty-nine individuals with a history of calcium oxalate kidney stones (19 men, 10 women) and 19 age-matched NSFs (8 men, 11 women) participated in two 6-day controlled feeding experimental periods: ascorbate-supplement (2 g/d) and no-supplement treatments. An oxalate load consisting of 118 mg of unlabeled oxalate and 18 mg of 13C2 -oxalic acid was administered the morning of day 6 of each experimental period. Mean 13C2 -oxalic acid absorption averaged across the ascorbate and no-supplement treatments was significantly greater in SFs (9.9%) than NSFs (8.0%). SFs also had significantly greater 24-hour post-oxalate load urinary total oxalate and endogenous oxalate levels with both treatments. Twenty-four-hour urinary total oxalate level correlated strongly with both 13C2 -oxalic acid absorption (SFs, r = 0.76; P < 0.01; NSFs, r = 0.62; P < 0.01) and endogenous oxalate synthesis (SFs, r = 0.95; P < 0.01; NSFs, r = 0.92; P < 0.01). SFs are characterized by greater rates of both oxalate absorption and endogenous oxalate synthesis, and both these factors contribute to the hyperoxaluric state. The finding that ascorbate supplementation increased urinary total and endogenous oxalate levels suggested that this practice is a risk factor for individuals predisposed to kidney stones.

Clinical factors associated with postoperative hydronephrosis after ureteroscopic lithotripsy.

PubMed

Kim, Sun Woo; Ahn, Ji Hoon; Yim, Sang Un; Cho, Yang Hyun; Shin, Bo Sung; Chung, Ho Seok; Hwang, Eu Chang; Yu, Ho Song; Oh, Kyung Jin; Kim, Sun-Ouck; Jung, Seung Il; Kang, Taek Won; Kwon, Dong Deuk; Park, Kwangsung

2016-09-01

This study aimed to determine the predictors of ipsilateral hydronephrosis after ureteroscopic lithotripsy for ureteral calculi. From January 2010 to December 2014, a total of 204 patients with ureteral calculi who underwent ureteroscopic lithotripsy were reviewed. Patients with lack of clinical data, presence of ureteral rupture, and who underwent simultaneous percutaneous nephrolithotomy (PNL) were excluded. Postoperative hydronephrosis was determined via computed tomographic scan or renal ultrasonography, at 6 months after ureteroscopic lithotripsy. Multivariable analysis was performed to determine clinical factors associated with ipsilateral hydronephrosis. A total of 137 patients were enrolled in this study. The mean age of the patients was 58.8±14.2 years and the mean stone size was 10.0±4.6 mm. The stone-free rate was 85.4%. Overall, 44 of the 137 patients (32.1%) had postoperative hydronephrosis. Significant differences between the hydronephrosis and nonhydronephrosis groups were noted in terms of stone location, preoperative hydronephrosis, impacted stone, operation time, and ureteral stent duration (all, p<0.05). On multivariable analysis, increasing preoperative diameter of the hydronephrotic kidney (adjusted odds ratio [OR], 1.21; 95% confidence interval [CI], 1.12-1.31; p=0.001) and impacted stone (adjusted OR, 3.01; 95% CI, 1.15-7.61; p=0.031) independently predicted the occurrence of postoperative hydronpehrosis. Large preoperative diameter of the hydronephrotic kidney and presence of impacted stones were associated with hydronephrosis after ureteroscopic stone removal. Therefore, patients with these predictive factors undergo more intensive imaging follow-up in order to prevent renal deterioration due to postoperative hydronephrosis.

Clinical factors associated with postoperative hydronephrosis after ureteroscopic lithotripsy

PubMed Central

Kim, Sun Woo; Ahn, Ji Hoon; Yim, Sang Un; Cho, Yang Hyun; Shin, Bo Sung; Chung, Ho Seok; Yu, Ho Song; Oh, Kyung Jin; Kim, Sun-Ouck; Jung, Seung Il; Kang, Taek Won; Kwon, Dong Deuk; Park, Kwangsung

2016-01-01

Purpose This study aimed to determine the predictors of ipsilateral hydronephrosis after ureteroscopic lithotripsy for ureteral calculi. Materials and Methods From January 2010 to December 2014, a total of 204 patients with ureteral calculi who underwent ureteroscopic lithotripsy were reviewed. Patients with lack of clinical data, presence of ureteral rupture, and who underwent simultaneous percutaneous nephrolithotomy (PNL) were excluded. Postoperative hydronephrosis was determined via computed tomographic scan or renal ultrasonography, at 6 months after ureteroscopic lithotripsy. Multivariable analysis was performed to determine clinical factors associated with ipsilateral hydronephrosis. Results A total of 137 patients were enrolled in this study. The mean age of the patients was 58.8±14.2 years and the mean stone size was 10.0±4.6 mm. The stone-free rate was 85.4%. Overall, 44 of the 137 patients (32.1%) had postoperative hydronephrosis. Significant differences between the hydronephrosis and nonhydronephrosis groups were noted in terms of stone location, preoperative hydronephrosis, impacted stone, operation time, and ureteral stent duration (all, p<0.05). On multivariable analysis, increasing preoperative diameter of the hydronephrotic kidney (adjusted odds ratio [OR], 1.21; 95% confidence interval [CI], 1.12–1.31; p=0.001) and impacted stone (adjusted OR, 3.01; 95% CI, 1.15–7.61; p=0.031) independently predicted the occurrence of postoperative hydronpehrosis. Conclusions Large preoperative diameter of the hydronephrotic kidney and presence of impacted stones were associated with hydronephrosis after ureteroscopic stone removal. Therefore, patients with these predictive factors undergo more intensive imaging follow-up in order to prevent renal deterioration due to postoperative hydronephrosis. PMID:27617316

Outcomes of ureteroscopy for patients with stones in a solitary kidney: evidence from a systematic review

PubMed Central

Rai, Bhavan Prasad; Somani, Bhaskar K.

2016-01-01

Introduction Management of urolithiasis in a solitary functioning kidney can be clinically challenging. The aim of this article was to review the outcomes of URS for patients with stone disease in a solitary kidney and critically appraise the existing evidence and outcome reporting standards. Material and methods We conducted a systematic review in line with PRISMA checklist and Cochrane guidelines between January 1980 and February 2015. Our inclusion criteria were all English language articles reporting on a minimum of 10 patients with a solitary kidney undergoing ureteroscopy for stone disease. Results A total of 116 patients (mean age 50 years) underwent URS for stones in solitary kidney. For a mean stone size of 16.8 mm (range: 5–60 mm) and 1.23 procedures/patient, the mean stone free rate was 87%. No significant change in renal function was recorded in any of the studies although a transient elevation in creatinine was reported in 10 (8.6%) patients. A total of 33 (28%) complications were recorded a majority (n = 21) of which were Clavien grade I. The Clavien grade II/III complications as reported by authors were urosepsis, steinstrasse and renal colic. None of the procedures required conversion to open surgery with no cases of renal haematoma or ureteric perforation. Conclusions This contemporary review highlights URS as a viable treatment option for stone disease in patients with a solitary kidney. It is associated with superior clearance rates to SWL and fewer high-risk complications compared to PCNL. PMID:27123332

Extracellular vesicles in urine of women with but not without kidney stones manifest patterns similar to men: a case control study.

PubMed

Jayachandran, Muthuvel; Lugo, Ghiara; Heiling, Hillary; Miller, Virginia M; Rule, Andrew D; Lieske, John C

2015-01-01

The lifetime incidence of kidney stones is about two times greater in men compared to women. Extracellular vesicles (EVs) shed from activated cells are present in the urine and may reflect or even mediate renal physiology and/or pathology. This study was designed to standardize methodology to characterize urinary EVs by digital flow cytometry and to identify possible sex differences in EVs in persons with and without their first symptomatic kidney stones. Twenty-four-hour urine collections were obtained from persons presenting with their first kidney stone episode (n = 50 women, 60 men; age 19-76 years) and sex- and age-matched controls from the general population (n = 24 women, 36 men). Standardization: Size of EV was variable within all groups. EV positivity was verified with two fluorophores for surface phosphatidylserine and/or using two different protein markers specific for renal-specific cells. The number of phosphatidylserine- and exosome marker-positive EVs did not correlate with urine osmolality and were similar in fresh vs. frozen and between two sequential urine collections from the same individual. Sex differences: Urine from women controls contained greater (P < 0.05) numbers of EVs positive for phosphatidylserine, exosomes, inflammatory factors and adhesion molecules, and cell-specific markers from different segments of the nephron, renal pelvis, and bladder compared to control men. In contrast, urine from women with kidney stones contained significantly (P < 0.05) lower numbers of EVs derived from podocytes, parietal cells, proximal convoluted tubule, thin and thick loop of Henle, distal tubule, collecting duct, renal pelvis, and bladder compared to control women and contained similar quantities of these types of EVs in men with and without kidney stones. There were also no sex differences in EVs positive for cell adhesion (E-cadherin and inter-cellular adhesion molecule-1 [ICAM-1]) molecules. Unlike women who do not have kidney stones, EVs in urine from women with nephrolithiasis are similar to men with and without kidney stones. Thus, EVs may mediate or reflect aspects of kidney stone pathogenesis and perhaps provide clues regarding sex differences in kidney stone incidence rates.

THE CORE OF THE PSEUDOSTEM OF MUSA IN THE TREATMENT OF URINARY STONES

PubMed Central

Pillai, R. Gopakumara

1995-01-01

Ayurveda recommends many simple herbs in the treatment of urological afflictions like urolithiasis. Seventyone patients diagnosed to be suffering from urolithiasis were treated with juice of the core of the pseudostem of Musa Paradisiaca and Musa sapientum. A significant segment of them passed out calculi of varying size after consuming the drug for two weeks. Recurrence of stone formation was also prevented by the treatment, The author concludes that the plant material is quite effective in curing urolithiasis, especially of the calcium oxalate variety. PMID:22556713

Evaluation and medical management of kidney stones in children.

PubMed

Tasian, Gregory E; Copelovitch, Lawrence

2014-11-01

We review the current literature on the diagnostic evaluation and dietary and pharmacological management of children with nephrolithiasis. We searched MEDLINE(®), Embase(®) and the Cochrane Library from their inceptions to March 2014 for published articles in English on kidney stones and therapy in children 0 to 18 years old. Based on review of the titles and abstracts, 110 of the 1,014 articles (11%) were potentially relevant to the diagnostic evaluation and medical management of nephrolithiasis in children. We summarized this literature and drew on studies performed in adult populations to augment areas in which no studies of sufficient quality have been performed in children, and to highlight areas in need of research. During the last 25 years the incidence of nephrolithiasis in children has increased by approximately 6% to 10% annually and is now 50 per 100,000 adolescents. Kidney stones that form during childhood have a similar composition to those that form in adulthood. Approximately 75% to 80% of stones are composed of predominantly calcium oxalate, 5% to 10% are predominantly calcium phosphate, 10% to 20% are struvite and 5% are pure uric acid. The recurrence rate of nephrolithiasis in patients with stones that form during childhood is poorly defined. Ultrasound should be used as the initial imaging study to evaluate children with suspected nephrolithiasis, with noncontrast computerized tomography reserved for those in whom ultrasound is nondiagnostic and the suspicion of nephrolithiasis remains high. Current treatment strategies for children with kidney stone disease are based largely on extrapolation of studies performed in adult stone formers and single institution cohort or case series studies of children. Tamsulosin likely increases the spontaneous passage of ureteral stones in children. Increased water intake and reduction of salt consumption should be recommended for all children with a history of kidney stones. Potassium citrate is a potentially effective medication for children with calcium oxalate stones and concomitant hypocitraturia, as well as children with uric acid stones. However, long-term compliance with therapy and the effect on decreasing stone recurrence in children are unknown. Based largely on efficacy in adult populations, thiazide diuretics should be considered in the treatment of children with calcium based stones and persistent hypercalciuria refractory to reductions in salt intake. The incidence of kidney stone disease in children is increasing, yet few randomized clinical trials or high quality observational studies have assessed whether dietary or pharmacological interventions decrease the recurrence of kidney stones in children. Collaborative efforts and randomized clinical trials are needed to determine the efficacy and effectiveness of alternative treatments for children with nephrolithiasis, particularly those with calcium oxalate stones and concomitant hypercalciuria and hypocitraturia. Additional areas in need of study are the optimal length of time for a trial of stone passage in children, the cost-effectiveness of medical expulsive therapy vs analgesics alone, and the size and location of stones for which medical expulsive therapy is most effective. Copyright © 2014 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

The age of the hominin fossils from Jebel Irhoud, Morocco, and the origins of the Middle Stone Age.

PubMed

Richter, Daniel; Grün, Rainer; Joannes-Boyau, Renaud; Steele, Teresa E; Amani, Fethi; Rué, Mathieu; Fernandes, Paul; Raynal, Jean-Paul; Geraads, Denis; Ben-Ncer, Abdelouahed; Hublin, Jean-Jacques; McPherron, Shannon P

2017-06-07

The timing and location of the emergence of our species and of associated behavioural changes are crucial for our understanding of human evolution. The earliest fossil attributed to a modern form of Homo sapiens comes from eastern Africa and is approximately 195 thousand years old, therefore the emergence of modern human biology is commonly placed at around 200 thousand years ago. The earliest Middle Stone Age assemblages come from eastern and southern Africa but date much earlier. Here we report the ages, determined by thermoluminescence dating, of fire-heated flint artefacts obtained from new excavations at the Middle Stone Age site of Jebel Irhoud, Morocco, which are directly associated with newly discovered remains of H. sapiens. A weighted average age places these Middle Stone Age artefacts and fossils at 315 ± 34 thousand years ago. Support is obtained through the recalculated uranium series with electron spin resonance date of 286 ± 32 thousand years ago for a tooth from the Irhoud 3 hominin mandible. These ages are also consistent with the faunal and microfaunal assemblages and almost double the previous age estimates for the lower part of the deposits. The north African site of Jebel Irhoud contains one of the earliest directly dated Middle Stone Age assemblages, and its associated human remains are the oldest reported for H. sapiens. The emergence of our species and of the Middle Stone Age appear to be close in time, and these data suggest a larger scale, potentially pan-African, origin for both.

Does quality of drinking water matter in kidney stone disease: A study in West Bengal, India.

PubMed

Mitra, Pubali; Pal, Dilip Kumar; Das, Madhusudan

2018-05-01

The combined interaction of epidemiology, environmental exposure, dietary habits, and genetic factors causes kidney stone disease (KSD), a common public health problem worldwide. Because a high water intake (>3 L daily) is widely recommended by physicians to prevent KSD, the present study evaluated whether the quantity of water that people consume daily is associated with KSD and whether the quality of drinking water has any effect on disease prevalence. Information regarding residential address, daily volume of water consumption, and source of drinking water was collected from 1,266 patients with kidney stones in West Bengal, India. Drinking water was collected by use of proper methods from case (high stone prevalence) and control (zero stone prevalence) areas thrice yearly. Water samples were analyzed for pH, alkalinity, hardness, total dissolved solutes, electrical conductivity, and salinity. Average values of the studied parameters were compared to determine if there were any statistically significant differences between the case and control areas. We observed that as many as 53.6% of the patients consumed <3 L of water daily. Analysis of drinking water samples from case and control areas, however, did not show any statistically significant alterations in the studied parameters. All water samples were found to be suitable for consumption. It is not the quality of water, rather the quantity of water consumed that matters most in the occurrence of KSD.

Femtosecond laser lithotripsy: feasibility and ablation mechanism.

PubMed

Qiu, Jinze; Teichman, Joel M H; Wang, Tianyi; Neev, Joseph; Glickman, Randolph D; Chan, Kin Foong; Milner, Thomas E

2010-01-01

Light emitted from a femtosecond laser is capable of plasma-induced ablation of various materials. We tested the feasibility of utilizing femtosecond-pulsed laser radiation (lambda=800 nm, 140 fs, 0.9 mJ/pulse) for ablation of urinary calculi. Ablation craters were observed in human calculi of greater than 90% calcium oxalate monohydrate (COM), cystine (CYST), or magnesium ammonium phosphate hexahydrate (MAPH). Largest crater volumes were achieved on CYST stones, among the most difficult stones to fragment using Holmium:YAG (Ho:YAG) lithotripsy. Diameter of debris was characterized using optical microscopy and found to be less than 20 microm, substantially smaller than that produced by long-pulsed Ho:YAG ablation. Stone retropulsion, monitored by a high-speed camera system with a spatial resolution of 15 microm, was negligible for stones with mass as small as 0.06 g. Peak shock wave pressures were less than 2 bars, measured by a polyvinylidene fluoride (PVDF) needle hydrophone. Ablation dynamics were visualized and characterized with pump-probe imaging and fast flash photography and correlated to shock wave pressures. Because femtosecond-pulsed laser ablates urinary calculi of soft and hard compositions, with micron-sized debris, negligible stone retropulsion, and small shock wave pressures, we conclude that the approach is a promising candidate technique for lithotripsy.

The effect of force on laser fiber burnback during lithotripsy

NASA Astrophysics Data System (ADS)

Aryaei, Ashkan; Chia, Ray; Peng, Steven

2018-02-01

Optical fibers for lithotripsy are designed to deliver the maximum energy precisely to the treatment site without a decrease in performance and without increasing the risks to patients and users. One of the obstacles to constant energy delivery is burnback of the optical fiber tip. So far, researchers identified mechanical, thermal, and optical factors as mechanisms in burnback phenomena. Among mechanical factors, the force applied by urologists against a stone is expected to play a dominant role in burnback. In this study, we introduce a novel technique to measure accurately the stone depth and volume ablation under varying force. Our results show varying burnback lengths on the optical fibers and varying stone depth and volume ablation depending on the optical fiber core size. For instance, the slope of the burnback as a function of the applied force for 273 μm fibers was more than two times higher than for the 550 μm fibers. The slope of the total volume of stone ablated as function of force for 550 μm fibers was almost twice as much as for the 273 μm fibers. The data suggest urologists can maximize the stone ablation rate and minimize fiber tip burnback by controlling the applied force on the optical fiber during a lithotripsy procedure.

Spatial-temporal patterns in Mediterranean carnivore road casualties: Consequences for mitigation

USGS Publications Warehouse

Grilo, C.; Bissonette, J.A.; Santos-Reis, M.

2009-01-01

Many carnivores have been seriously impacted by the expansion of transportation systems and networks; however we know little about carnivore response to the extent and magnitude of road mortality, or which age classes may be disproportionately impacted. Recent research has demonstrated that wildlife-vehicle-collisions (WVC) involving carnivores are modulated by temporal and spatial factors. Thus, we investigated road mortality on a guild of small and medium-sized carnivores in southern Portugal using road-kill data obtained from a systematic 36 months monitoring period along highways (260 km) and national roads (314 km) by addressing the following questions: (a) which species and age class are most vulnerable to WVC? (b) are there temporal and/or spatial patterns in road-kill? and (c) which life-history and/or spatial factors influence the likelihood of collisions? We recorded a total of 806 carnivore casualties, which represented an average of 47 ind./100 km/year. Red fox and stone marten had the highest mortality rates. Our findings highlight three key messages: (1) the majority of road-killed individuals were adults of common species; (2) all carnivores, except genets, were more vulnerable during specific life-history phenological periods: higher casualties were observed when red fox and stone marten were provisioning young, Eurasian badger casualties occurred more frequently during dispersal, and higher Egyptian mongoose mortality occurred during the breeding period; and (3) modeling demonstrated that favorable habitat, curves in the road, and low human disturbance were major contributors to the deadliest road segments. Red fox carcasses were more likely to be found on road sections with passages distant from urban areas. Conversely, stone marten mortalities were found more often on national roads with high of cork oak woodland cover; Egyptian mongoose and genet road-kills were found more often on road segments close to curves. Based on our results, two key mitigation measures should help to reduce WVC in Portugal. The first involves the improvement of existing crossings with buried and small mesh size fence to guide the individuals towards to the passages, in road segments with high traffic volume (>1200 vehicles/night) and located in preferred carnivore habitats. The second mitigation involves cutting or removal of dense vegetation in verges of road segments with curves to aid motorists in seeing animals about to cross. ?? 2008 Elsevier Ltd.

Feasibility study of prompt gamma neutron activation for NDT measurement of moisture in stone and brick

DOE Office of Scientific and Technical Information (OSTI.GOV)

Livingston, R. A.; Al-Sheikhly, M.; Grissom, C.

2014-02-18

The conservation of stone and brick architecture or sculpture often involves damage caused by moisture. The feasibility of a NDT method based on prompt gamma neutron activation (PGNA) for measuring the element hydrogen as an indication of water is being evaluated. This includes systematic characterization of the lithology and physical properties of seven building stones and one brick type used in the buildings of the Smithsonian Institution in Washington, D.C. To determine the required dynamic range of the NDT method, moisture-related properties were measured by standard methods. Cold neutron PGNA was also used to determine chemically bound water (CBW) content.more » The CBW does not damage porous masonry, but creates an H background that defines the minimum level of detection of damaging moisture. The CBW was on the order of 0.5% for all the stones. This rules out the measurement of hygric processes in all of the stones and hydric processed for the stones with fine scale pore-size distributions The upper bound of moisture content, set by porosity through water immersion, was on the order of 5%. The dynamic range is about 10–20. The H count rates were roughly 1–3 cps. Taking into account differences in neutron energies and fluxes and sample volume between cold PGNA and a portable PGNA instrument, it appears that it is feasible to apply PGNA in the field.« less

Electrokinetic lithotripsy: safety, efficacy and limitations of a new form of ballistic lithotripsy.

PubMed

Keeley, F X; Pillai, M; Smith, G; Chrisofos, M; Tolley, D A

1999-08-01

To investigate the safety and efficacy of electrokinetic lithotripsy (EKL), a ballistic lithotripter which uses high-energy magnetic fields to propel an impactor to fragment calculi. The records and radiographs of 121 patients who underwent ureteroscopy using the EKL for stones in the upper (26), mid (28) or lower (67) ureter were reviewed retrospectively. Ureteroscopy was performed with an 8.5 F semi-rigid ureteroscope, through which a 3 F EKL probe was passed. A total of 148 stones (mean stone size 11.5 mm, range 6-40) in 121 patients were treated using the EKL. One patient was lost to follow-up. Of 148 stones, 147 (99.3%) were fragmented, including five that had resisted fragmentation with either pulsed-dye laser or electrohydraulic lithotripsy. Despite this, only 45 of 56 patients (80%) with a single stone in the lower ureter were rendered stone-free after a single ureteroscopic procedure. Seven patients in this group (12%) required shock-wave lithotripsy for fragments that had been propelled into the kidney, while four patients (7%) required repeat ureteroscopy for retained ureteric fragments. Complications were limited to minor ureteric perforations in two patients, both of which were treated with a stent. EKL is an inexpensive and reliable endoscopic method which fragments nearly all urinary calculi. Its limitations include the propulsion of fragments and the need to use an offset, semi-rigid ureteroscope. We recommend the use of a basket or graspers to remove fragments of >/=4 mm after EKL.

Ureteral stone location at emergency room presentation with colic.

PubMed

Eisner, Brian H; Reese, Adam; Sheth, Sonali; Stoller, Marshall L

2009-07-01

It is thought that the 3 narrowest points of the ureter are the ureteropelvic junction, the point where the ureter crosses anterior to the iliac vessels and the ureterovesical junction. Textbooks describe these 3 sites as the most likely places for ureteral stones to lodge. We defined the stone position in the ureter when patients first present to the emergency department with colic. We retrospectively reviewed the records of 94 consecutive patients who presented to the emergency department with a chief complaint of colic and computerized tomography showing a single unilateral ureteral calculus. Axial, coronal and 3-dimensional reformatted computerized tomography scans were evaluated, and stone position and size (maximal axial and coronal diameters) were recorded, as were the position of the ureteropelvic junction, the iliac vessels (where the ureter crosses anterior to the iliac vessels) and the ureterovesical junction. Patients with a history of nephrolithiasis, shock wave lithotripsy, ureteroscopy or percutaneous nephrolithotripsy were excluded from study. Statistical analysis was performed using Student's t test and Pearson's correlation coefficient. At the time of emergency department presentation for colic ureteral stone position was the ureteropelvic junction in 10.6% cases, between the ureteropelvic junction and the iliac vessels in 23.4%, where the ureter crosses anterior to the iliac vessels in 1.1%, between the iliac vessels and the ureterovesical junction in 4.3% and at the ureterovesical junction in 60.6%. Proximal calculi had a greater axial diameter than distal calculi (mean 6.1 vs 4.0 mm) and a greater coronal diameter than distal calculi (6.8 vs 4.1 mm, each p <0.001). Axial and coronal diameters moderately correlated with stone position (r = -0.47 and -0.55, respectively, each p <0.001). Proximal ureteral stones were larger in axial and coronal diameter than distal ureteral stones. At emergency department presentation for colic most stones were at the ureterovesical junction and in the proximal ureter between the ureteropelvic junction and the iliac vessels. A few stones were at the ureteropelvic junction and only 1 lodged at the level where the ureter crosses anterior to the iliac vessels, despite the literature stating that these locations are 2 of the 3 most likely places for stones to become lodged.

Changes in urinary risk profile after short-term low sodium and low calcium diet in recurrent Swiss kidney stone formers.

PubMed

Seeger, Harald; Kaelin, Andrea; Ferraro, Pietro M; Weber, Damian; Jaeger, Philippe; Ambuehl, Patrice; Robertson, William G; Unwin, Robert; Wagner, Carsten A; Mohebbi, Nilufar

2017-12-04

Kidney stone disease is common in industrialized countries. Recently, it has attracted growing attention, because of its significant association with adverse renal outcomes, including end stage renal disease. Calcium-containing kidney stones are frequent with high recurrence rates. While hypercalciuria is a well-known risk factor, restricted intake of animal protein and sodium, combined with normal dietary calcium, has been shown to be more effective in stone prevention compared with a low-calcium diet. Notably, the average sodium intake in Switzerland is twice as high as the WHO recommendation, while the intake of milk and dairy products is low. We retrospectively analyzed Swiss recurrent kidney stone formers (rKSF) to test the impact of a low-sodium in combination with a low-calcium diet on the urinary risk profile. In patients with recurrent calcium oxalate containing stones, we investigated both, the consequence of a low-sodium diet on urinary volume and calcium excretion, and the influence of a low-sodium low-calcium diet on urinary oxalate excretion. Of the 169 patients with CaOx stones, 49 presented with hypercalciuria at baseline. The diet resulted in a highly significant reduction in 24-h urinary sodium and calcium excretion: from 201 ± 89 at baseline to 128 ± 88 mmol/d for sodium (p < 0.0001), and from 5.67 ± 3.01 to 4.06 ± 2.46 mmol/d (p < 0.0001) for calcium, respectively. Urine volume remained unchanged. Notably, no increase in oxalate excretion occurred on the restricted diet (0.39 ± 0.26 vs 0.39 ± 0.19 mmol/d, p = 0.277). Calculated Psf (probability of stone formation) values were only predictive for the risk of calcium phosphate stones. A diet low in sodium and calcium in recurrent calcium oxalate stone formers resulted in a significant reduction of urinary calcium excretion, but no change in urine volume. In this population with apparently low intake of dairy products, calcium restriction does not necessarily result in increased urinary oxalate excretion. However, based on previous studies, we recommend a normal dietary calcium intake to avoid a potential increase in urinary oxalate excretion and unfavorable effects on bone metabolism in hypercalciuric KSFs.

Fluid dynamic modelling of renal pelvic pressure during endoscopic stone removal

NASA Astrophysics Data System (ADS)

Oratis, Alexandros; Subasic, John; Bird, James; Eisner, Brian

2015-11-01

Endoscopic kidney stone removal procedures are known to increase internal pressure in the renal pelvis, the kidney's urinary collecting system. High renal pelvic pressure incites systemic absorption of irrigation fluid, which can increase the risk of postoperative fever and sepsis or the unwanted absorption of electrolytes. Urologists choose the appropriate surgical procedure based on patient history and kidney stone size. However, no study has been conducted to compare the pressure profiles of each procedure, nor is there a precise sense of how the renal pelvic pressure scales with various operational parameters. Here we develop physical models for the flow rates and renal pelvic pressure for various procedures. We show that the results of our models are consistent with existing urological data on each procedure and that the models can predict pressure profiles where data is unavailable.

Flexible ureterorenoscopy versus miniaturized PNL for solitary renal calculi of 10-30 mm size.

PubMed

Knoll, Thomas; Jessen, Jan Peter; Honeck, Patrick; Wendt-Nordahl, Gunnar

2011-12-01

The value of flexible ureterorenoscopy (fURS) and miniaturized PNL (mPNL) for larger renal calculi is under discussion. This non-randomized prospective study aimed to evaluate fURS and mPNL for solitary renal stones of 10-30 mm size. fURS was carried out in 21 patients with last generation 7.5F endoscopes. Ureteral access sheaths were used in 19 patients. For mPNL, an 18F modified Amplatz sheath with a 14F nephroscope were used (n = 25). The procedure was performed either tubeless with an antegrade stent or a nephrostomy. Outcome and complications of both procedures were assessed. Patients' demographics and stone sizes were comparable (18 ± 5 vs. 19 ± 4 mm, P = 0.08). Patients in the fURS group had a higher mean BMI (31 vs. 27, P < 0.05). Total OR time was significantly longer for fURS (106 ± 51 vs. 59 ± 19 min., P < 0.001). More patients were stone-free after one single percutaneous treatment, while 2nd-stage treatments with fURS were common (total procedures 1.04 vs. 1.52, P < 0.001; immediate stone-free rate (SFR) 96% vs. 71.5%, P < 0.001). SFR after 4 weeks was 100% (mPNL) and 85.8% (fURS) (P < 0.01). Minor complications as classified by Clavien I or II occurred in 16 and 23.8%, mPNL and fURS, respectively, P = 0.13). No major complications (Clavien III-V) occured in both groups. Our series supports both the concept of either percutaneous or retrograde endoscopic treatment for renal calculi with both modalities offering excellent safety. However, while for fURS, a significantly higher rate of 2nd-stage procedures was necessary, and mPNL led to faster and higher SFR without increasing complication rate.

Plain radiography, renography, and 99mTc-DMSA renal scintigraphy before and after extracorporeal shock wave lithotripsy for urolithiasis.

PubMed

Munck, O; Gerquari, I; Møller, J T; Jensen, L I; Thomsen, H S

1992-11-01

Eighteen patients were evaluated before and 5 weeks after the first treatment with extracorporeal shock wave lithotripsy (ESWL) using abdominal plain radiography, 131I-hippuran probe renography, and 99mTc-dimercaptosuccinic acid scintigraphy. In 6 patients no urolithiasis was present on the post ESWL plain radiograph, in 7 the size had decreased, and in 5 the stone mass was unchanged. The renograms were within normal range in the 6 patients who were cured by ESWL, whereas this was the case for only 4 of the 12 who still had renal calculi. In 2 patients pelvic stones had descended into the ureter after ESWL, and the renograms indicated obstruction. Another 3 patients had ureteral stones, whereas in the remaining 7 patients only pelvic stones were found on the plain radiographs. In no patient did the scintigrams reveal scars. It is concluded that abdominal plain radiography of the urinary tract and probe renography are complementary and sufficient in the monitoring of patients with urolithiasis post ESWL.

Simulation of root forms using cellular automata model

NASA Astrophysics Data System (ADS)

Winarno, Nanang; Prima, Eka Cahya; Afifah, Ratih Mega Ayu

2016-02-01

This research aims to produce a simulation program for root forms using cellular automata model. Stephen Wolfram in his book entitled "A New Kind of Science" discusses the formation rules based on the statistical analysis. In accordance with Stephen Wolfram's investigation, the research will develop a basic idea of computer program using Delphi 7 programming language. To best of our knowledge, there is no previous research developing a simulation describing root forms using the cellular automata model compared to the natural root form with the presence of stone addition as the disturbance. The result shows that (1) the simulation used four rules comparing results of the program towards the natural photographs and each rule had shown different root forms; (2) the stone disturbances prevent the root growth and the multiplication of root forms had been successfully modeled. Therefore, this research had added some stones, which have size of 120 cells placed randomly in the soil. Like in nature, stones cannot be penetrated by plant roots. The result showed that it is very likely to further develop the program of simulating root forms by 50 variations.

Super-mini percutaneous nephrolithotomy (SMP): a new concept in technique and instrumentation.

PubMed

Zeng, Guohua; Wan, ShawPong; Zhao, Zhijian; Zhu, Jianguo; Tuerxun, Aierken; Song, Chao; Zhong, Liang; Liu, Ming; Xu, Kewei; Li, Hulin; Jiang, Zhiqiang; Khadgi, Sanjay; Pal, Shashi K; Liu, Jianjun; Zhang, Guoxi; Liu, Yongda; Wu, Wenqi; Chen, Wenzhong; Sarica, Kemal

2016-04-01

To present a novel miniature endoscopic system designed to improve the safety and efficacy of percutaneous nephrolithotomy, named the 'super-mini percutaneous nephrolithotomy' (SMP). The endoscopic system consists of a 7-F nephroscope with enhanced irrigation and a modified 10-14 F access sheath with a suction-evacuation function. This system was tested in patients with renal stones of <2.5 cm, in a multicentre prospective non-randomised clinical trial. In all, 146 patients were accrued in 14 centres. Nephrostomy tract dilatation was carried out to 10-14 F. The lithotripsy was performed using either a Holmium laser or pneumatic lithotripter. A nephrostomy tube or JJ stent was placed only if clinically indicated. SMP was completed successfully in 141 of 146 patients. Five patients required conversion to larger nephrostomy tracts. The mean (sd) stone size was 2.2 (0.6) cm and the mean operative duration was 45.6 min. The initial stone-free rate (SFR) was 90.1%. The SFR at the 3-month follow-up was 95.8%. Three patients required auxiliary procedures for residual stones. Complications occurred in 12.8% of the patients, all of which were Clavien grade ≤II and no transfusions were needed. In all, 72.3% of the patients did not require any kind of catheter, while 19.8% had JJ stents and 5.7% had nephrostomy tubes placed. The mean hospital stay was 2.1 days. SMP is a safe and effective treatment for renal stones of <2.5 cm. SMP may be particularly suitable for patients with lower pole stones and stones that ae not amenable to retrograde intrarenal surgery. © 2015 The Authors BJU International © 2015 BJU International Published by John Wiley & Sons Ltd.

Screening and Management of Asymptomatic Renal Stones in Astronauts

NASA Technical Reports Server (NTRS)

Reyes, David; Locke, James; Sargsyan, Ashot; Garcia, Kathleen

2017-01-01

Management guidelines were created to screen and manage asymptomatic renal stones in U.S. astronauts. The true risk for renal stone formation in astronauts due to the space flight environment is unknown. Proper management of this condition is crucial to mitigate health and mission risks. The NASA Flight Medicine Clinic electronic medical record and the Lifetime Surveillance of Astronaut Health databases were reviewed. An extensive review of the literature and current aeromedical standards for the monitoring and management of renal stones was also done. This work was used to develop a screening and management protocol for renal stones in astronauts that is relevant to the spaceflight operational environment. In the proposed guidelines all astronauts receive a yearly screening and post-flight renal ultrasound using a novel ultrasound protocol. The ultrasound protocol uses a combination of factors, including: size, position, shadow, twinkle and dispersion properties to confirm the presence of a renal calcification. For mission-assigned astronauts, any positive ultrasound study is followed by a low-dose renal computed tomography scan and urologic consult. Other specific guidelines were also created. A small asymptomatic renal stone within the renal collecting system may become symptomatic at any time, and therefore affect launch and flight schedules, or cause incapacitation during a mission. Astronauts in need of definitive care can be evacuated from the International Space Station, but for deep space missions evacuation is impossible. The new screening and management algorithm has been implemented and the initial round of screening ultrasounds is under way. Data from these exams will better define the incidence of renal stones in U.S. astronauts, and will be used to inform risk mitigation for both short and long duration spaceflights.

Wild capuchin monkeys (Cebus libidinosus) use anvils and stone pounding tools.

PubMed

Fragaszy, Dorothy; Izar, Patrícia; Visalberghi, Elisabetta; Ottoni, Eduardo B; de Oliveira, Marino Gomes

2004-12-01

We conducted an exploratory investigation in an area where nut-cracking by wild capuchin monkeys is common knowledge among local residents. In addition to observing male and female capuchin monkeys using stones to pound open nuts on stone "anvils," we surveyed the surrounding area and found physical evidence that monkeys cracked nuts on rock outcrops, boulders, and logs (collectively termed anvils). Anvils, which were identified by numerous shallow depressions on the upper surface, the presence of palm shells and debris, and the presence of loose stones of an appropriate size to pound nuts, were present even on the tops of mesas. The stones used to crack nuts can weigh >1 kg, and are remarkably heavy for monkeys that weigh <4 kg. The abundance of shell remains and depressions in the anvil surface at numerous anvil sites indicate that nut-cracking activity is common and long-enduring. Many of the stones found on anvils (presumably used to pound nuts) are river pebbles that are not present in the local area we surveyed (except on or near the anvils); therefore, we surmise that they were transported to the anvil sites. Ecologically and behaviorally, nut-cracking by capuchins appears to have strong parallels to nut-cracking by wild chimpanzees. The presence of abundant anvil sites, limited alternative food resources, abundance of palms, and the habit of the palms in this region to produce fruit at ground level all likely contribute to the monkeys' routine exploitation of palm nuts via cracking them with stones. This discovery provides a new reference point for discussions regarding the evolution of tool use and material culture in primates. Routine tool use to exploit keystone food resources is not restricted to living great apes and ancestral hominids. Copyright 2004 Wiley-Liss, Inc.

Safety and efficacy of retrograde intrarenal surgery in patients of different age groups.

PubMed

Tolga-Gulpinar, M; Resorlu, B; Atis, G; Tepeler, A; Ozyuvali, E; Oztuna, D; Resorlu, M; Akbas, A; Sancak, E B; Unsal, A

2015-01-01

To assess the efficacy and safety of retrograde intrarenal surgery (RIRS) to treat renal stones in different age groups of patients. We performed a retrospective analysis of 947 patients who underwent RIRS for renal calculi between January 2008 and January 2014. Age at RIRS was analysed both as a continuous and categorical variable and patients were categorized into three age groups; aged ≤ 15 years at surgery (group i, n=51), 16 - 60 years (group Ii, n=726) and>60 years (group iii, n=170). We compared the 3 groups with the regard to stone characteristics, operative parameters and postoperative outcomes. The stone-free rate was 78.4% in group i, 77.5% in group ii, and 81.1% in group iii (P=.587). A multivariate logistic regression analysis showed that only stone size and stone number had significant influence on the stone-free rates after RIRS. Intraoperative complications occurred 13.7% in group i, 5.6% group ii, and 7.6% in group iii. Overall complication rates in children were higher than adult patients but the differences were not statistically significant. We found that only operation time was associated with the increased risk of intraoperative complications. Peroperative medical complications developed in 8 patients (.8%) in group ii and 2 patients (1.1%) in group iii. A 48-year-old man died from septic shock 5 days after the surgery. RIRS was observed to be a safe and effective procedure in all age groups of patients with stone disease, therefore age should not be considered as a limiting factor. Copyright © 2014 AEU. Publicado por Elsevier España, S.L.U. All rights reserved.

Safety and efficacy of silodosin and tadalafil in ease of negotiation of large ureteroscope in the management of ureteral stone: A prosective randomized trial.

PubMed

Bhattar, Rohit; Jain, Vipin; Tomar, Vinay; Yadav, Sher Singh

2017-12-01

To evaluate the safety and efficacy of silodosin and tadalafil in ease of negotiation of large size ureteroscope (8/9.8 Fr) in the management of ureteral stone. Between June 2015 and May 2016, 86 patients presented with ureteral stone of size 6-15 mm were on consent randomly assigned to 1 of 3 outpatient treatment arms: silodosin (Group A), tadalafil (Group B), and placebo (Group C). After two weeks of therapy 67 patients underwent ureteroscopy, and ureteral orifice configuration, ureteroscopic negotiation, ureteral dilatation, operating time, procedural complication and drug related side effects were noted in each group. Ureteral negotiation was significantly better in Groups A (73.9%) and B (69.6%) as compared to Group C (38.1%) (p<0.01). Statistically significant difference was noted in the requirement for dilatation in Group C (71.4%) as compared to Groups A (26.1%) and B (39.1%) (p<0.01). Ureteral orifice was found to be more dilated in Groups A (69.6%) and B (60.9%) as compared to Group C (28.6%). Mean operating time was statistically lower in Groups A (35.2 min) and B (34.91 min) as compared to Group C (41.14 min) (p<0.01). Both silodosin and tadalafil not only relax ureteral smooth muscle but also help in forward propagation of large size ureteroscope (8/9.8 Fr) without any significant risk of adverse events.

Aerodynamic Analysis of Tektites and Their Parent Bodies

NASA Technical Reports Server (NTRS)

Adams, E. W.; Huffaker, R. M.

1962-01-01

Experiment and analysis indicate that the button-type australites were derived from glassy spheres which entered or re-entered the atmosphere as cold solid bodies; in case of average-size specimens, the entry direction was nearly horizontal and the entry speed between 6.5 and 11.2 km/sec. Terrestrial origin of such spheres is impossible because of extremely high deceleration rates at low altitudes. The limited extension of the strewn fields rules out extraterrestrial origin of clusters of such spheres because of stability considerations for clusters in space. However, tektites may have been released as liquid droplets from glassy parent bodies ablating in the atmosphere of the earth. The australites then have skipped together with the parent body in order to re-enter as cold spheres. Terrestrial origin of a parent body would require an extremely violent natural event. Ablation analysis shows that fusion of opaque siliceous stone into glass by aerodynamic heating is impossible.

Solar heating and hot water system installed at Municipal Building complex, Abbeville, South Carolina

NASA Technical Reports Server (NTRS)

1979-01-01

Information on the solar energy system installed at the new municipal building for the City of Abbeville, SC is presented, including a description of solar energy system and buildings, lessons learned, and recommendations. The solar space heating system is a direct air heating system. The flat roof collector panel was sized to provide 75% of the heating requirement based on an average day in January. The collectors used are job-built with two layers of filon corrugated fiberglass FRP panels cross lapped make up the cover. The storage consists of a pit filled with washed 3/4 in - 1 1/2 in diameter crushed granite stone. The air handler includes the air handling mechanism, motorized dampers, air circulating blower, sensors, control relays and mode control unit. Solar heating of water is provided only those times when the hot air in the collector is exhausted to the outside.

Characterization methodology for re-using marble slurry in industrial applications

NASA Astrophysics Data System (ADS)

Marras, Graziella; Careddu, Nicola; Peretti, Roberto; Bortolussi, Augusto

2017-04-01

In the effort towards waste minimization and circular economy, natural stone waste is one of the foremost parameter to turn scientific community attention. At this time, calcium carbonate has a great importance in industrial fields and currently there is the necessity of appreciate the potential value of marble waste and convert it into marketable products. A large amount of residues is produced in ornamental stone sector with different dimension and particle size. The research focused on marble slurry, recovered at the end of the treatment plant in the filter-press section. The aim of this paper is to propose a defined way to characterize marble slurry, primarily composed of micronized particles, in order to obtain useful data to make a comparison with market specifications. In particular the proposed characterization methodology follows the indicated steps: Leaching test (TCLP) - Grain size distribution and bulk density - Mineralogical analyses - X-Ray diffraction - Chemical analysis - Loss on ignition - SEM determination - Colorimetric and bright analysis. Marble slurry samples, collected by different dimension stone treatment plants in Orosei marble district (Sardinia - Italy), were analyzed by physical, mineralogical and chemical determinations and the obtained data were evaluated for compatibility with the CaCO3 specifications required by a definite industrial sector, seeing as how CaCO3 product specifications vary depending on the utilization. The importance of this investigation is to characterize completely the "waste" that must apply for further uses and to identify the feasibility to substitute marketable micronized CaCO3 with marble slurry. Further goal is to enhance the environmental advantages of re-using stone waste by reducing marble waste landfills and by applying raw material substitution, in accordance with regulatory requirements, thus pursuing the objective to convert natural stone waste into by-product with a renewed environmental and economic value. Consequently what until now was considered as a waste, can be an important economic resource capable of promoting the sustainability.

[Electrohydraulic intracorporeal lithotripsy of salivary calculi. In vitro and animal experiment studies].

PubMed

Iro, H; Zenk, J; Hosemann, W G; Benzel, W

1993-08-01

Extracorporeal lithotripsy is now used routinely for the treatment of salivary duct stones. The question arose whether electrohydraulic intracorporeal lithotripsy, which is applied in urology and gastroenterology, might also be useful in the treatment of this disease. Before its possible clinical application the influence of electrohydraulic intracorporeal shock waves on salivary stones in vitro and any influence on the tissue in the head and neck region (in vivo) had to be investigated. In vitro experiments. Fifty-eight salivary stones and 11 extirpated human submandibular glands were treated by three different electrohydraulic devices. Animal experiments. Electrohydraulic shock waves were applied to the dilated Stensen's duct and other tissues (muscle, parotid gland, facial nerve) of six rabbits. Of 58 salivary stones, 53 (91%) were fragmented, 39 (67%) with a remaining size of less than 1.5 mm and 14 (24%) more than 1.5 mm. In 5 cases (9%) no effects were seen at all. Fragmentation occurred independent of the mineralogical components of the stone and independent of the different lithotriptors used. The smaller the probe diameter and the larger the stone, the more shock waves were needed to achieve fragmentation. With the smaller probes the stones could not be fragmented completely. In human submandibular glands, extensive tissue lesions could be evidenced macroscopically and histologically after application of electrohydraulic shock waves in vitro. Application of electrohydraulic shock waves to the dilated parotid gland duct of rabbits led to perforations of the duct after 1-5 single pulses. Lesions of nerves and blood vessels could also be observed within the duct environment. This occurred with all of the different electrohydraulic devices, probe diameters and intensities used. In our opinion the damage produced is probably the result of both the direct effect of the plasma as well as the resultant stress wave. In view of the severe damage caused to different tissues, use of the described method for the treatment of stones in the narrow human salivary ducts should be greatly restricted.

Flexible ureteroscopic laser lithotripsy for upper urinary tract stone disease in patients with spinal cord injury.

PubMed

Tepeler, Abdulkadir; Sninsky, Brian C; Nakada, Stephen Y

2015-11-01

The objective of this study is to present the outcomes of flexible ureteroscopic laser lithotripsy (URS) for upper urinary tract stone disease in spinal cord injury (SCI) patients performed by a single surgeon. A retrospective analysis was performed for SCI patients treated with flexible URS for proximal ureter and kidney stone disease by a single surgeon between 2003 and 2013. Patient characteristics, operative outcomes, metabolic evaluation, and stone analyses were assessed in detail. A total of 27 URS procedures were performed for urolithiasis in 21 renal units of 19 patients. The mean age was 52.1 ± 15.6 years (16-72) and mean BMI was 29.2 ± 7.3 kg/m(2) (20-45.7). Etiology of SCI was trauma (n: 10), multiple sclerosis (n: 6), cerebrovascular accident (n: 1), or undetermined (n: 2). The mean stone size was 15.9 ± 8.6 (6-40) mm. In the 27 URS procedures, stones were located in the ureter (n: 5), the kidney (n: 14), and both areas (n: 8). Mean hospitalization time was 2.0 ± 2.4 (0-10) days. Postoperative complications were observed in 6 cases (22.2%). Three major complications included urosepsis (n: 1) and respiratory failure (n: 2), that were observed postoperatively and required admission to the intensive care unit. The 2 minor complications were hypotension, fever and UTI, and required medical treatment. Fourteen (66.6%) of the 21 renal units were stone free. Calcium phosphate carbonate (n: 9) and struvite (n: 5) were the primary stone compositions detected. Hypocitraturia (n: 6), hypercalciuria (n: 5), hypernaturia (n: 5), hyperoxaluria (n: 4), and hyperuricosuria (n: 1) were common abnormalities in 24-h urine analysis. Ureteroscopic laser lithotripsy can be an effective treatment modality for SCI patients with upper urinary tract calculi.

Pre- and Postoperative Predictors of Infection-Related Complications in Patients Undergoing Percutaneous Nephrolithotomy.

PubMed

Rivera, Marcelino; Viers, Boyd; Cockerill, Patrick; Agarwal, Deepak; Mehta, Ramila; Krambeck, Amy

2016-09-01

We aim to describe pre- and postoperative predictors of infection-related complications in individuals undergoing percutaneous nephrolithotomy (PCNL). Patients treated with PCNL from 2009 to 2013 were reviewed. Patients with positive urine or stone cultures received extended antimicrobial treatment. All others received 7 days of empirical therapy preoperatively and postoperatively. Pre- and postoperative predictors of infectious complication were identified. We identified 227 patients who underwent primary PCNL with infectious complications occurring in 37 (16%): 11 (5%) urinary tract infection/pyelonephritis, 21 (9%) systemic inflammatory response syndrome (SIRS), and 2 (0.9%) sepsis. There were no significant differences between those with and without infectious complication with regard to age, gender, stone size, presence of diabetes, or procedure duration. Those with infectious complication were more likely to have a positive intraoperative stone culture (p = 0.01), struvite stone composition (p < 0.01), staghorn calculi (p < 0.001), and multiple stones (p = 0.02). Preoperatively, on multivariable analysis, only the presence of a staghorn calculus remained independently associated with increased risks of fever/SIRS/sepsis (odds ratio [OR] 3.14; p = 0.02) and total infectious complications (OR 2.53; p = 0.02) following PCNL. After controlling for pre- and post-PCNL risk factors, again, only staghorn calculi remained significantly associated with fever/SIRS/sepsis (OR 3.41; p = 0.01) and total infectious complications (OR 2.91; p = 0.01), with presence of multiple stones approaching significance (OR 4.2, confidence interval [CI]: 0.96, 18.6; p = 0.06). In individuals undergoing PCNL on preoperative antibiotics, risk of SIRS/sepsis was low. The presence of a staghorn calculus confers a greater than threefold increased risk of postoperative infection with multiple stones approaching a significant risk. Patients with large stone burdens should be counseled appropriately regarding these risks.

Systematic review and meta-analysis of the clinical effectiveness of shock wave lithotripsy, retrograde intrarenal surgery, and percutaneous nephrolithotomy for lower-pole renal stones.

PubMed

Donaldson, James F; Lardas, Michael; Scrimgeour, Duncan; Stewart, Fiona; MacLennan, Steven; Lam, Thomas B L; McClinton, Samuel

2015-04-01

The prevalence of urolithiasis is increasing. Lower-pole stones (LPS) are the most common renal calculi and the most likely to require treatment. A systematic review comparing shock wave lithotripsy (SWL), retrograde intrarenal surgery (RIRS), and percutaneous nephrolithotomy (PNL) in the treatment of ≤20 mm LPS in adults was performed. Comprehensive searches revealed 2741 records; 7 randomised controlled trials (RCTs) recruiting 691 patients were included. Meta-analyses for stone-free rate (SFR) at ≤3 mo favoured PNL over SWL (risk ratio [RR]: 2.04; 95% confidence interval [CI], 1.50-2.77) and RIRS over SWL (RR: 1.31; 95% CI, 1.08-1.59). Stone size subgroup analyses revealed PNL and RIRS were considerably more effective than SWL for >10 mm stones, but the magnitude of benefit was markedly less for ≤10 mm stones. The quality of evidence (Grading of Recommendations Assessment, Development, and Evaluation [GRADE]) for SFR was moderate for these comparisons. The median SFR from reported RCTs suggests PNL is more effective than RIRS. The findings regarding other outcomes were inconclusive because of limited and inconsistent data. Well-designed, prospective, comparative studies that measure these outcomes using standardised definitions are required, particularly for the direct comparison of PNL and RIRS. This systematic review, which used Cochrane methodology and GRADE quality-of-evidence assessment, provides the first level 1a evidence for the management of LPS. We thoroughly examined the literature to compare the benefits and harms of the different ways of treating kidney stones located at the lower pole. PNL and RIRS were superior to SWL in clearing the stones within 3 mo, but we were unable to make any conclusions regarding other outcomes. More data is required from reliable studies before firm recommendations can be made. Copyright © 2014 European Association of Urology. Published by Elsevier B.V. All rights reserved.

Comparative testing of reliability and audit utility of ordinal objective calculus complexity scores. Can we make an informed choice yet?

PubMed

Jaipuria, Jiten; Suryavanshi, Manav; Sen, Tridib K

2016-12-01

To assess the reliability of the Guy's Stone Score, the Seoul National University Renal Stone Complexity (S-ReSC) score and the S.T.O.N.E. scores in percutaneous nephrolithotomy (PCNL), and assess their utility in discriminating outcomes [stone free rate (SFR), complications, need for multiple PCNL sessions, and auxiliary procedures] valid across parameters of experience of surgeon, independence from surgical approach, and variations in institution-specific instrumentation. A prospectively maintained database of two tertiary institutions was analysed (606 cases). Institutes differed in instrumentation, while the overall surgical team comprised: two trainees (experience <100 cases), two junior consultants (experience 100-200 cases), and two senior surgeons (experience >1000 cases). Scores were assigned and re-assigned after 4 months by one trainee and an expert surgeon. Inter-rater and test-retest agreement were analysed by Cohen's κ and intraclass correlation coefficient. Multivariate logistic regression models were created adjusting outcomes for the institution, comorbidity, Amplatz size, access tract location, the number of punctures, the experience level of the surgeon, and individual scoring system, and receiver operating curves were analysed for comparison. Despite some areas of inconsistencies, individually all scores had excellent inter-rater and test-retest concordance. On multivariable analyses, while the experience of the surgeon and surgical approach characteristics (such as access tract location, Amplatz size, and number of punctures) remained independently associated with different outcomes in varying combinations, calculus complexity scores were found consistently to be independently associated with all outcomes. The S-ReSC score had a superior association with SFR, the need for multiple PCNL sessions, and auxiliary procedures. Individually all scoring systems performed well. On cross comparison, the S-ReSC score consistently emerged to be more superiorly associated with all outcomes, signifying the importance of the distributional complexity of the calculus (which also indirectly amalgamates the influence of stone number, size, and anatomical location) in discriminating outcomes. Our study proves the utility of scoring systems in prognosticating multiple outcomes and also clarifies important aspects of their practical application including future roles such as benchmarking, audit, training, and objective assessment of surgical technique modifications. © 2016 The Authors BJU International © 2016 BJU International Published by John Wiley & Sons Ltd.

The effects of ambient temperature, humidity and season of year on urine composition in patients with nephrolithiasis.

PubMed

Eisner, Brian H; Sheth, Sonali; Herrick, Benjamin; Pais, Vernon M; Sawyer, Mark; Miller, Nicole; Hurd, Kimberly J; Humphreys, Mitchell R

2012-12-01

Study Type--Prognosis (cohort series) Level of Evidence 2b. What's known on the subject? and What does the study add? Epidemiologic studies have shown that warmer climates are associated with increased incidence of nephrolithiasis. Many hypothesize that this is due to dehydration and lower urine volumes. The current study of stone formers reports that greater temperatures are associated with significant increases in urine calcium which may shed light on the mechanism underlying the increased stone incidence associated with increased ambient temperature. • To understand the effects of temperature, humidity and season of year on 24-h urine composition in patients with nephrolithiasis. • A retrospective review was performed of patients evaluated at four metabolic stone clinics. • Multivariate linear regression models examined the relationship between mean temperature, average humidity, season of year and 24-h urine composition. • Multivariate models adjusted for known risk factors for stone disease. • Mean temperature and average humidity data were obtained from http://www.weatherunderground.com based on patient-provided addresses. • A total of 599 patients were included in the study, comprising 239 women and 360 men with a mean age of 53.6 years (sd 15.0). • Mean temperature was 16.9 °C (sd 4.8, range -21.1 to 38.3 °C) and average humidity was 58.1% (sd 23.5, range 11-100%). • On multivariate linear regression, increasing temperature was associated with increasing urine calcium (β = 11.3, 95% CI 2.2-20.0), super-saturation of calcium oxalate (β = 0.6, 95% CI 0.2-0.9), super-saturation of calcium phosphate (β = 0.14, 95% CI 0.03-0.2), and decreasing urine sodium (β = -5.2, 95% CI -10.3 to -0.1). • As seasons become warmer (i.e. from winter to autumn to spring to summer), changes were increased urine volume (β = 0.09, 95% CI 0.01-0.2) and decreased super-saturation of calcium phosphate (β = -0.2, 95% CI -0.3 to -0.03). • There were no associations between quintile of humidity and any 24-h urine constituents. • Increasing temperature may increase stone risk by increasing urine excretion of calcium, and the super-saturation of calcium oxalate and calcium phosphate. • These findings were independent of humidity and of season of year. • This appears to be related to a physiological impact of temperature itself, rather than to geographic location. © 2012 BJU INTERNATIONAL.

[Analysis of particle size characteristics of road sediments in Beijing Olympic Park].

PubMed

Li, Hai-yan; Shi, An-bang; Qu, Yang-sheng; Yue, Jing-lin

2014-09-01

Particle size analysis of road sediment collected in October and November in Beijing Olympic Park indicates that most of the sediments are 76-830 μm; the grain size of the sediments in the area of large population flow is mainly coarse but the grain size in the area of large traffic volume is fine relatively while most of the sediments are <300 p.m. Moreover, sediments of size range <300 μm can be easily accumulated on the road with moderate traffic density. The results demonstrate that the effect of pedestrian flow on the composition of the particles is unobvious and the main influences are the traffic density, extensive construction. With the length of dry period increasing, the content of sediments of size range >300 μm decreases and the content of sediments of size range < 150 μm increases, however, the change of the content of sediments of size range 150-300 μm is not obvious. The results indicate that the effectiveness of the road sediment removal depends on the length of dry period, and the accumulation of different size particles varies differently under the different dry days. Compared with the stone road, surface particles can accumulate on the asphalt road more easily as the accumulation of particles is affected by the road material significantly. Therefore, to reduce the urban surface water pollution, it is necessary to improve the design of park road such as using the stone road, which can decrease the roughness of the road.

MEASUREMENT OF RADON, THORON AND THEIR PROGENY IN DIFFERENT TYPES OF DWELLING IN ALMORA DISTRICT OF KUMAUN HIMALAYAN REGION.

PubMed

Singh, Kuldeep; Semwal, Poonam; Pant, Preeti; Gusain, G S; Joshi, Manish; Sapra, B K; Ramola, R C

2016-10-01

The indoor concentrations of radon ( 222 Rn), thoron ( 220 Rn) and their daughter products were measured in the dwellings of Almora district in Kumaun Himalaya, India using pin-hole dosemeters and deposition progeny sensors. The measurements were made in the residential houses built of mud, stone with cement plaster and cemented house during winter season. Average [geometric mean (GM) values] radon and thoron concentrations for all dwellings were found to be 99.82 and 79.70 Bq m -3 , respectively, while average equilibrium equivalent radon concentration and equilibrium equivalent thoron concentration (measured for the first time for this region) were measured at 35.22 and 2.52 Bq m -3 , respectively. Radon concentration (GM values) was found to be 110.73, 97.00 and 93.85 Bq m -3 for mud houses, stone with cemented plaster houses and cemented houses, respectively. On the other hand, thoron concentration values were 87.10, 75.79 and 75.68 Bq m -3 for cemented houses, mud houses and stone with cemented plaster houses, respectively. Interpretations have been made on the basis of measured radon/thoron and progeny concentration values with respect to the difference of construction material of the dwellings. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

[Current status of extracorporeal shock wave lithotripsy in urinary lithiasis.

PubMed

Pereira-Arias, Jose Gregorio; Gamarra-Quintanilla, Mikel; Urdaneta-Salegui, Luis Felipe; Mora-Christian, Jorge Alberto; Sánchez-Vazquez, Andrea; Astobieta-Odriozola, Ander; Ibarluzea-González, Gaspar

2017-03-01

Over the last decade, urinary lithiasis' prevalence has dramatically increased due to diet and lifestyle changes, growing 10.6% and 7.1% in men and women respectively. Extracorporeal shock wave lithotripsy has lost relevance in current practice due to endoscopic device development and unpredictability of results. Instrument miniaturization is leading to an increase of the percutaneous approach of increasingly smaller stones, while most flexible ureteroscopes durability and digitalization has allowed urologists to address larger stones. So that, decision algorithm is now impossible to define, but what is clear is that ESWL has declined worldwide. Can it disappear as a urinary lithiasis treatment modality? If we don't improve appropriate candidate selection and optimize disintegration efficiency, guidelines are going to replace the more "boring" ESWL by popular and more attractive endoscopes. Shock wave technology has evolved in the last two decades, however lithotripsy fundamental principle has not changed. ESWL has passed the test of time and centers dedicated to stone treatment should have a lithotripter in order to offer an appropriate balance in different options for different clinical situations. New developments will be focused on improvements in location (in-line navigation systems; Vision track system) and automatic ultrasound location on a robotic arm; monitoring and stone fixation, implementation of different focal sizes with new acoustic lenses, multitask working stations that allow endourological approach, coupling control (avoiding microbubbles) and low cost devices for different applications. On the other hand, optimizing outcomes by: slower pulse rates, ramping strategies and patient selection with soft stones, short stone-skin distance, low BMI and favorable collecting system anatomy, allow us to achieve better outcomes in shock wave treatments. SWL still represents a unique non invasive method of stone disease treatment with no anesthesia and low complication rates; and a high proportion of stones could still be treated with shock waves and remains among patient's first options. This update objective has been to review the evolution, identify shock wave new developments and clarify their impact on our daily practice in urinary stones treatment.

A multi-reader in vitro study using porcine kidneys to determine the impact of integrated circuit detectors and iterative reconstruction on the detection accuracy, size measurement, and radiation dose for small (<4 mm) renal stones.

PubMed

Wells, Michael L; Froemming, Adam T; Kawashima, Akira; Vrtiska, Terri J; Kim, Bohyun; Hartman, Robert P; Holmes, David R; Carter, Rickey E; Bartley, Adam C; Leng, Shuai; McCollough, Cynthia H; Fletcher, Joel G

2017-08-01

Background Detection of small renal calculi has benefitted from recent advances in computed tomography (CT) scanner design. Information regarding observer performance when using state-of-the-art CT scanners for this application is needed. Purpose To assess observer performance and the impact of radiation dose for detection and size measurement of <4 mm renal stones using CT with integrated circuit detectors and iterative reconstruction. Material and Methods Twenty-nine <4 mm calcium oxalate stones were randomly placed in 20 porcine kidneys in an anthropomorphic phantom. Four radiologists used a workstation to record each calculus detection and size. JAFROC Figure of Merit (FOM), sensitivity, false positive detections, and calculus size were calculated. Results Mean calculus size was 2.2 ± 0.7 mm. The CTDI vol values corresponding to the automatic exposure control settings of 160, 80, 40, 25, and 10 Quality Reference mAs (QRM) were 15.2, 7.9, 4.2, 2.7, and 1.3 mGy, respectively. JAFROC FOM was ≥ 0.97 at ≥ 80 QRM, ≥ 0.89 at ≥ 25 QRM, and was inferior to routine dose (160 QRM) at 10 QRM (0.72, P < 0.05). Per-calculus sensitivity remained ≥ 85% for every reader at ≥ 25 QRM. Mean total false positive detections per reader were ≤ 3 at ≥ 80 QRM, but increased substantially for two readers ( ≥ 12) at ≤ 40 QRM. Measured calculus size significantly decreased at ≤ 25 QRM ( P ≤ 0.01). Conclusion Using low dose renal CT with iterative reconstruction and ≥ 25 QRM results in high sensitivity, but false positive detections increase for some readers at very low dose levels (≤ 40 QRM). At very low doses with iterative reconstruction, measured calculus size will artifactually decrease.

Ultra-mini-percutaneous nephrolithotomy in pediatric nephrolithiasis: both low pressure and high efficiency.

PubMed

Dede, Onur; Sancaktutar, Ahmet Ali; Dağguli, Mansur; Utangaç, Mazhar; Baş, Okan; Penbegul, Necmettin

2015-10-01

The management of urolithiasis in children differs from adults because of anatomic and metabolic abnormalities. At present, various minimally invasive and invasive treatment strategies have been recommended to treat urinary tract Stones, including shock wave lithotripsy (SWL), standard percutaneous nephrolithotomy (PNL), mini-PNL, retrograde intrarenal surgery (RIRS), micro-PNL, and a new technique termed ultra-mini PNL (UMP). UMP is a new method for the treatment of kidney stones. The main difference between UMP and standard PNL or mini-PNL lies in the small access sheath and in its design. A 9.5F pediatric compact cystoscope was used (Figure). A major advantage of UMP is that it provides similar stone-free rates when compared with standard PNL, with lower intrarenal pressure than micro-PNL. The aim of the study was to determine the applicability and safety of UMP in the treatment of pediatric kidney stones. We retrospectively reviewed the files of 39 kidney stones in children who had undergone UMP between May 2011 and October 2014. The indications for UMP included stones resistant to SWL, stones requiring repeated sessions of SWL, and stones size larger than 20 mm. The study included 17 females and 22 males, with a mean age of 5.8 ± 4.6 years. The mean hemoglobin loss was 0.9 ± 0.6 mg/dL and none of the patients required a blood transfusion. The complication rate of the PNL procedure was 15.3% (n = 6). Complete clearance was achieved in 32 patients (82%) with UMP monotherapy, which increased to 34% (87.1%) 4 weeks after the operation. Management of urolithiasis necessitates a balance between stone clearance and morbidity related to the procedure. SWL often leads to persistent residual stones. The developing RIRS can minimize the risks associated with bleeding and visceral injury, but sometimes the abnormal pelvicaliceal anatomy and poor imaging of the flexible ureteroscopy may impact its success rate and applications. It has been reported that PNL can be performed safely and effectively to achieve a higher stone-free rate; however, it has serious complications such as bleeding that requires blood transfusion in 11-14% of the cases with increased risk of kidney loss. The recent development of smaller sheaths allows tract formation with minimal damage to the renal parenchyma, thereby reducing procedure-related morbidity without diminishing its therapeutic efficacy. The most important advantage of this surgical technique that has been developed is similar stone-free rates to standard PNL and lower intrarenal pressure than micro-PNL. Our experience supports that UMP is safe and effective for the management of renal stones in children. Copyright © 2015 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

Postoperative ERCP versus laparoscopic choledochotomy for clearance of selected bile duct calculi: a randomized trial.

PubMed

Nathanson, Leslie K; O'Rourke, Nicholas A; Martin, Ian J; Fielding, George A; Cowen, Alistair E; Roberts, Roderick K; Kendall, Bradley J; Kerlin, Paul; Devereux, Benedict M

2005-08-01

Prospectively evaluate whether for patients having laparoscopic cholecystectomy with failed trans-cystic duct clearance of bile duct (BD) stones they should have laparoscopic choledochotomy or postoperative endoscopic retrograde cholangiography (ERCP). Clinical management of BD stones found at laparoscopic cholecystectomy in the last decade has focused on pre-cholecystectomy detection with ERCP clearance in those with suspected stones. This clinical algorithm successfully clears the stones in most patients, but no stones are found in 20% to 60% of patients and rare unpredictably severe ERCP morbidity can result in this group. Our initial experience of 300 consecutive patients with fluoroscopic cholangiography and intraoperative clearance demonstrated that, for the pattern of stone disease we see, 66% of patients' BD stones can be cleared via the cystic duct with dramatic reduction in morbidity compared to the 33% requiring choledochotomy or ERCP. Given the limitations of the preoperative approach to BD stone clearance, this trial was designed to explore the limitations, for patients failing laparoscopic trans-cystic clearance, of laparoscopic choledochotomy or postoperative ERCP. Across 7 metropolitan hospitals after failed trans-cystic duct clearance, patients were intraoperatively randomized to have either laparoscopic choledochotomy or postoperative ERCP. Exclusion criteria were: ERCP prior to referral for cholecystectomy, severe cholangitis or pancreatitis requiring immediate ERCP drainage, common BD diameter of less than 7 mm diameter, or if bilio-enteric drainage was required in addition to stone clearance. Drain decompression of the cleared BD was used in the presence of cholangitis, an edematous ampulla due to instrumentation or stone impaction and technical difficulties from local inflammation and fibrosis. The ERCP occurred prior to discharge from hospital. Mechanical and extracorporeal shockwave lithotripsy was available. Sphincter balloon dilation as an alternative to sphincterotomy to allow stone extraction was not used. Major endpoints for the trial were operative time, morbidity, retained stone rate, reoperation rate, and hospital stay. From June 1998 to February 2003, 372 patients with BD stones had successful trans-cystic duct clearance of stones in 286, leaving 86 patients randomized into the trial. Total operative time was 10.9 minutes longer in the choledochotomy group (158.8 minutes), with slightly shorter hospital stay 6.4 days versus 7.7 days. Bile leak occurred in 14.6% of those having choledochotomy with similar rates of pancreatitis (7.3% versus 8.8%), retained stones (2.4% versus 4.4%), reoperation (7.3% versus 6.6%), and overall morbidity (17% versus 13%). These data suggest that the majority of secondary BD stones can be diagnosed at the time of cholecystectomy and cleared trans-cystically, with those failing having either choledochotomy or postoperative ERCP. However, because of the small trial size, a significant chance exists that small differences in outcome may exist. We would avoid choledochotomy in ducts less than 7 mm measured at the time of operative cholangiogram and severely inflamed friable tissues leading to a difficult dissection. We would advocate choledochotomy as a good choice for patients after Billroth 11 gastrectomy, failed ERCP access, or where long delays would occur for patient transfer to other locations for the ERCP.

Opening ambulatory surgery centers and stone surgery rates in health care markets.

PubMed

Hollingsworth, John M; Krein, Sarah L; Birkmeyer, John D; Ye, Zaojun; Kim, Hyungjin Myra; Zhang, Yun; Hollenbeck, Brent K

2010-09-01

Ambulatory surgery centers deliver surgical care more efficiently than hospitals but may increase overall procedure use and adversely affect competing hospitals. Motivated by these concerns we evaluated how opening of an ambulatory surgery center impacts stone surgery use in a health care market and assessed the effect of its opening on the patient mix at nearby hospitals. In a 100% sample of outpatient surgery from Florida we measured annual stone surgery use between 1998 and 2006. We used multiple regression to determine if the rate of change in use differed between markets, defined by the hospital service area, without and with a recently opened ambulatory surgery center. Stone surgery use increased an average of 11 procedures per 100,000 individuals per year (95% CI 1-20, p <0.001) after an ambulatory surgery center opened in a hospital service area. Four years after opening the relative increase in the stone surgery rate was approximately 64% higher (95% CI 27 to 102) in hospital service areas where a center opened vs hospital service areas without a center. These market level increases in surgery were not associated with decreased surgical volume at competing hospitals and the absolute change in patient disease severity treated at nearby hospitals was small. While opening of an ambulatory surgery center did not appear to have an overly detrimental effect on competing hospitals, it led to a significant increase in the population based rate of stone surgery in the hospital service area. Possible explanations are the role of physician financial incentives and unmet surgical demand. 2010 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Content and Face Validation of a Curriculum for Ultrasonic Propulsion of Calculi in a Human Renal Model

PubMed Central

Dunmire, Barbrina; Cunitz, Bryan W.; He, Xuemei; Sorensen, Mathew D.; Harper, Jonathan D.; Bailey, Michael R.; Lendvay, Thomas S.

2014-01-01

Abstract Purpose: Ultrasonic propulsion to reposition urinary tract calculi requires knowledge about ultrasound image capture, device manipulation, and interpretation. The purpose of this study was to validate a cognitive and technical skills curriculum to teach urologists ultrasonic propulsion to reposition kidney stones in tissue phantoms. Materials and Methods: Ten board-certified urologists recruited from a single institution underwent a didactic session on renal ultrasound imaging. Subjects completed technical skills modules in tissue phantoms, including kidney imaging, pushing a stone through a translucent maze, and repositioning a lower pole calyceal stone. Objective cognitive and technical performance metrics were recorded. Subjects completed a questionnaire to ascertain face and content validity on a five-point Likert scale. Results: Eight urologists (80%) had never attended a previous ultrasound course, and nine (90%) performed renal ultrasounds less frequently than every 6 months. Mean cognitive skills scores improved from 55% to 91% (p<0.0001) on pre- and post-didactic tests. In the kidney phantom, 10 subjects (100%) repositioned the lower pole calyceal stone to at least the lower pole infundibulum, while 9 (90%) successfully repositioned the stone to the renal pelvis. A mean±SD (15.7±13.3) pushes were required to complete the task over an average of 4.6±2.2 minutes. Urologists rated the curriculum's effectiveness and realism as a training tool at a mean score of 4.6/5.0 and 4.1/5.0, respectively. Conclusions: The curriculum for ultrasonic propulsion is effective and useful for training urologists with limited ultrasound proficiency in stone repositioning technique. Further studies in animate and human models will be required to assess predictive validity. PMID:24228719

Moderate high power 1 to 20μs and kHz Ho:YAG thin disk laser pulses for laser lithotripsy

NASA Astrophysics Data System (ADS)

Renz, Günther

2015-02-01

An acousto-optically or self-oscillation pulsed thin disk Ho:YAG laser system at 2.1 μm with an average power in the 10 W range will be presented for laser lithotripsy. In the case of cw operation the thin disk Ho:YAG is either pumped with InP diode stacks or with a thulium fiber laser which leads to a laser output power of 20 W at an optical-to-optical efficiency of 30%. For the gain switched mode of operation a modulated Tm-fiber laser is used to produce self-oscillation pulses. A favored pulse lengths for uric acid stone ablation is known to be at a few μs pulse duration which can be delivered by the thin disk laser technology. In the state of the art laser lithotripter, stone material is typically ablated with 250 to 750 μs pulses at 5 to 10 Hz and with pulse energies up to a few Joule. The ablation mechanism is performed in this case by vaporization into stone dust and fragmentation. With the thin disk laser technology, 1 to 20 μs-laser pulses with a repetition rate of a few kHz and with pulse energies in the mJ-range are available. The ablation mechanism is in this case due to a local heating of the stone material with a decomposition of the crystalline structure into calcium carbonate powder which can be handled by the human body. As a joint process to this thermal effect, imploding water vapor bubbles between the fiber end and the stone material produce sporadic shock waves which help clear out the stone dust and biological material.

Content and face validation of a curriculum for ultrasonic propulsion of calculi in a human renal model.

PubMed

Hsi, Ryan S; Dunmire, Barbrina; Cunitz, Bryan W; He, Xuemei; Sorensen, Mathew D; Harper, Jonathan D; Bailey, Michael R; Lendvay, Thomas S

2014-04-01

Ultrasonic propulsion to reposition urinary tract calculi requires knowledge about ultrasound image capture, device manipulation, and interpretation. The purpose of this study was to validate a cognitive and technical skills curriculum to teach urologists ultrasonic propulsion to reposition kidney stones in tissue phantoms. Ten board-certified urologists recruited from a single institution underwent a didactic session on renal ultrasound imaging. Subjects completed technical skills modules in tissue phantoms, including kidney imaging, pushing a stone through a translucent maze, and repositioning a lower pole calyceal stone. Objective cognitive and technical performance metrics were recorded. Subjects completed a questionnaire to ascertain face and content validity on a five-point Likert scale. Eight urologists (80%) had never attended a previous ultrasound course, and nine (90%) performed renal ultrasounds less frequently than every 6 months. Mean cognitive skills scores improved from 55% to 91% (p<0.0001) on pre- and post-didactic tests. In the kidney phantom, 10 subjects (100%) repositioned the lower pole calyceal stone to at least the lower pole infundibulum, while 9 (90%) successfully repositioned the stone to the renal pelvis. A mean±SD (15.7±13.3) pushes were required to complete the task over an average of 4.6±2.2 minutes. Urologists rated the curriculum's effectiveness and realism as a training tool at a mean score of 4.6/5.0 and 4.1/5.0, respectively. The curriculum for ultrasonic propulsion is effective and useful for training urologists with limited ultrasound proficiency in stone repositioning technique. Further studies in animate and human models will be required to assess predictive validity.

[Effects of retroperitoneal laparoscopic ureterolithotomy and flexible-ureteroscopic holmium laser lithotripsy for complex upper ureteral calculi].

PubMed

Zhang, L J; Wu, B; Zha, Z L; Zhao, H; Yang, W; Chen, X H; Jiang, B; Huang, Q; Li, W J; Yuan, J

2017-10-01

Objective: To explore the clinical effects of retroperitoneal laparoscopic ureterolithotomy (RPLU) and flexible-ureteroscopic holmium laser lithotripsy (f-UHLL) for complicated upper ureteral calculi. Methods: A total of 45 cases of complicated upper ureteral calculi between March 2014 and January 2016 in Department of Urology, Affiliated Jiangyin Hospital of Southeast University Medical College were retrospectively analyzed, there were 32 males and 13 females, ranging from 27 to 45 years with an average age of (34.1±9.5) years. Of the 45 patients, 28 had ureteral distortion and 17 had concurrent ureteral stones in the lower or middle ipsilateral ureter. In those patients, 20 cases underwent f-UHLL, and 25 cases received RPLU. The stone size, operation time, hospital stay, stone clearance rates and postoperative fever rates between the two groups were compared with t test and χ(2)test. Results: The operation was successfully performed in all patients, no complications with leakage of urine or ureteral perforation occurred, and no significant difference in renal function between the two methods were founded in postoperative period. There was no significant difference in operation time((78.4±8.5) minuetes vs .(73.3±11.3) minuetes, t =0.61, P =0.67), time of double J tube removed ((33.8±3.4)days vs . (37.6±8.9) d, t =2.37, P =0.08) and ipsilateral renal glomerular filtration rates ((41.3±7.6)ml/minuetes vs .(40.5±7.1) ml/min, t =0.78, P =1.27) between the two groups. However, the hospitalization time ((5.9±1.7)days vs . (4.2±1.6) days, t =1.92, P =0.04), postoperative fever rates (4% vs .30%, χ(2)=5.72, P =0.03) and calculus clearance rates (100% vs . 75%, χ(2)=7.03, P =0.01) in RPLU were significantly higher than f-UHLL. Besides, 5 patients in the f-UHLL group had postoperative stone residue and were treated with extracorpore shock wave lithotripsy. Conclusions: Both RPLU and f-UHLL are safety and validity for complex upper ureteral calculi. RPLU can improve the rate of calculus removal and reduce the rate of postoperative fever.

Extracorporeal shockwave lithotripsy in the management of salivary calculi.

PubMed

Escudier, M P; Brown, J E; Drage, N A; McGurk, M

2003-04-01

The aim was to investigate the results of extracorporeal shockwave lithotripsy in the management of salivary calculi using a dedicated sialolithotriptor. Some 122 salivary calculi (84 submandibular and 38 parotid) were treated in an experimental study using a sialolithotriptor. Complete success was achieved in 40 procedures (33 per cent), 27 of 84 submandibular and 13 of 38 parotid calculi. A further 43 patients (35 per cent) were rendered asymptomatic although some stone debris remained in the duct (26 submandibular and 17 parotid). Failure (retention of stone debris and continued symptoms) occurred in 39 patients (32 per cent), 30 submandibular and eight parotid glands. The chance of failure increased with the size of the calculus and increasing duration of symptoms. Extracorporeal shockwave lithotripsy provides a useful option for the management of salivary calculi, particularly for stones less than 7 mm in diameter. Copyright 2003 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.

Development of the Statocyst in Aplysia Californica. Part 1; Observations on Statoconial Development

NASA Technical Reports Server (NTRS)

Wiederhold, Michael L.; Sharma, Jyotsna S.; Driscoll, Brian P.; Harrison, Jeffrey L.

1990-01-01

The gravity receptor organs of gastropod molluscs, such as Aplysia californica, are bilateral paired statocysts, which contain dense statoconia within a fluid-filled cyst. Gravitational forces on the statoconia are sensed through their interaction with ciliated mechanoreceptor cells in the wall of the cyst. Larval Aplysia contain a single statolith within each statocyst; when the animals grow to a critical size, they begin producing multiple statoconia, a process that continues throughout life. The number of statoconia is highly correlated with animal weight but poorly correlated with age, indicating that stone production is related to total metabolism. The single statolith has an amorphous internal structure whereas the multiple statoconia have calcification deposited on concentric layers of membrane or matrix protein. The statolith appears to be produced within the cyst lumen but the multiple statoconia are produced within supporting cells between the receptor cells. Large adult animals have statoconia larger than those in early post-metamorphic animals which have just started producing multiple stones. The maximum statocyst diameter at which the receptor-cell cilia can suspend the statolith in the center of the cyst lumen is 45 micrometers; production of multiple stones begins when the cyst reaches this size. The mechanisms by which statoconia production is initiated and controlled are discussed.

The Swedish Bohus granite - a stone with a fascinating history

NASA Astrophysics Data System (ADS)

Schouenborg, Björn; Eliasson, Thomas

2015-04-01

One of the most well-known and well spread Swedish stone types used as building stones is the Bonus granite. It outcrops in an area north of Gothenburgh (SW Sweden), along the coastline, approximately 35 km wide and 85 km long. The granite continues into Norway as the Iddefjord granite. The Bohus granite is one of Sweden's youngest granites. Isotopic dating shows that the magma cooled at about 920 M years ago and thus marking the end of the Sveconorwegian orogoney. It is a composite granite massif area with several granitic intrusions but with rather homogeneous mineralogy. However, colour and texture varies quite a lot and the colour ranges from red to reddish grey although some pure grey varieties occur sparsely. The grain size ranges from medium grained to coarse grained and even with some porphyric parts. Quarrying in an industrial scale started 1842. The merchant A C Kullgren opened the first quarry and produced stones for the construction of the 86 km long Trollhättan channel connecting lake Vänern and the Atlantic ocean in the SW Sweden The stone was used for constructing harbors and wharves along the channel. Several quarries opened in the late 1800 around 1870 - 1890 and the export increased steadily with deliveries to Germany, Denmark, Holland, England and even to South America. The stone industries in Bohuslän (Bohus county), at its peak in 1929, engaged around 7 000 employees. During the depression in 1930 almost all of them became unemployed. However, as a curiosity, production and export continued to Germany for construction of Germania, the future World capital city ("Welthauptstadt Germania"), planned by Adolf Hitler and Albert Speer. About 500 stone workers were kept employed for this project during the late thirties. Today several varieties are still produced: Evja/Ävja, Tossene, Brastad, Näsinge, Broberg, Nolby, Allemarken and Skarstad. However, the number of stone workers is far from that of the early 1900. The Swedish production is mainly blocks but also paving products like sets, slabs and kerb stones are still manufactured in Sweden. Blocks are generally further processed in other countries like Italy and China to reach the European market as semi-finished products like slabs or finished products for any kind of application. The granite is very durable and suitable for all types of natural stone products.

Mechanical characterization of natural building stones: observation of the fracture process zone by ESPI

NASA Astrophysics Data System (ADS)

Calvetti, Francesco; Cardani, Giuliana; Meda, Alberto

1999-09-01

The cultural heritage of many nations consist of a great variety of structures of high intrinsic value, which are often composed of natural building stones (NBS), as granite, limestone, marble and sandstone. The use of accurate inspection devices, such as laser interferometry, allows us to acquire information regarding the mechanical properties and damage (tensile cracks) of NBS, which represents the first step in the restoration process. In this paper, the potential application of an electronic speckle pattern interferometry (ESPI) is shown, with particular attention to the observed displacement field and the crack penetration during laboratory testing. In ESPI, by superimposing a reflected light to a reference digitized image, an interference phenomenon is produced. By comparing two recorded interference patterns (before and after loading), the corresponding deformation can be evaluated. The application of ESPI in several laboratory tests on NBS is presented in this paper. In particular, during bending tests performed on geometrically similar NBS specimens, it was observed that the size and shape of the localized damage zone do not depend on the specimen size. These results allow for an interpretation of the 'size- effect,' which consists of a reduction of nominal strength as the specimen size increases.

Evaluation of Postoperative Hydronephrosis Following Ureteroscopy in Pediatric Population: Incidence and Predictors.

PubMed

Gökce, Mehmet Ilker; Telli, Onur; Özkıdık, Mete; Akıncı, Aykut; Hajıyev, Perviz; Soygür, Tarkan; Burgu, Berk

2016-07-01

To identify the incidence and associated factors of the postoperative hydronephrosis in pediatric patients who underwent ureterorenoscopy (URS) for renal or ureteral stones. We evaluated the results of 116 patients who underwent semirigid or flexible URS retrospectively. Primary end points of the study were to determine the incidence of postoperative hydronephrosis and factors associated with the development of postoperative hydronephrosis. Logistic regression analysis was used to define factors associated with the presence of hydronephrosis. Mean age of the population was 9.5 years and mean stone size was 9.4 mm. Hydronephrosis was detected in 32 (27.6%) patients. Stone-free status was achieved in 101 (87%) patients. Univariate analysis revealed history of ipsilateral URS, duration of operation, presence of impacted stone, development of ureteral injury during operation, and presentation with a renal colic episode as the parameter associated with increased risk of hydronephrosis. History of ipsilateral URS (odds ratio: 1.664, P = .027), presence of impacted stones (odds ratio: 1.788, P = .014), and development of ureteral injury during operation (odds ratio: 1.106, P = .039) were found to be the independent markers of developing postoperative hydronephrosis in a multivariate analysis. Ipsilateral hydronephrosis following URS develops in a significant portion of patients. In patients with history of ipsilateral procedure and those with an impacted stone and had ureteral injury, the risk of postoperative hydronephrosis is higher; therefore, physicians should keep these parameters in mind in the decision-making process of selective imaging postoperatively. Copyright © 2016 Elsevier Inc. All rights reserved.

Comparison of endoscopic papillary balloon dilation and sphincterotomy in young patients with CBD stones and gallstones.

PubMed

Seo, Yu Ri; Moon, Jong Ho; Choi, Hyun Jong; Kim, Dong Choon; Ha, Ji Su; Lee, Tae Hoon; Cha, Sang-Woo; Cho, Young Deok; Park, Sang-Heum; Kim, Sun-Joo

2014-05-01

Endoscopic biliary sphincterotomy (EBS) results in permanent loss of sphincter function and its long-term complications are unknown. Endoscopic papillary balloon dilation (EPBD) is an alternative procedure that preserves sphincter function, although it is associated with a higher risk of pancreatitis than is EBS. The aim of this study was to evaluate the safety and outcomes of EPBD with limited indications for removal of common bile duct (CBD) stones combined with gallstones in patients younger than 40 years. Young (age < 40 years) patients who had CBD stones combined with gallstones on imaging studies were enrolled in this study. A total of 132 patients were randomly divided into the EPBD group (n = 62) or the EBS group (n = 70) for extraction of CBD stones. The ballooning size of EPBD ranged from 6 to 10 mm. Complete bile duct clearance was achieved in 98.4 % (61/62) of the EPBD group and 100 % (70/70) of the EBS group. Mechanical lithotripsy was required in 8.1 % (5/62) of the EPBD group and 8.6 % (6/70) of the EBS group. The early complication rates were 8.1 % (5/62) (five pancreatitis) in the EPBD group and 11.4 % (8/70) (five [7.1 %] pancreatitis, two bleeding and one perforation) in the EBS group. The recurrence rates of CBD stones were 1.6 % (1/62) in the EPBD group and 5.7 % (4/70) in the EBS group. EPBD with limited indications was safe and effective as EBS for removal of CBD stones combined with gallstones in young patients who had a longer life expectancy.

Does quality of drinking water matter in kidney stone disease: A study in West Bengal, India

PubMed Central

Mitra, Pubali; Pal, Dilip Kumar

2018-01-01

Purpose The combined interaction of epidemiology, environmental exposure, dietary habits, and genetic factors causes kidney stone disease (KSD), a common public health problem worldwide. Because a high water intake (>3 L daily) is widely recommended by physicians to prevent KSD, the present study evaluated whether the quantity of water that people consume daily is associated with KSD and whether the quality of drinking water has any effect on disease prevalence. Materials and Methods Information regarding residential address, daily volume of water consumption, and source of drinking water was collected from 1,266 patients with kidney stones in West Bengal, India. Drinking water was collected by use of proper methods from case (high stone prevalence) and control (zero stone prevalence) areas thrice yearly. Water samples were analyzed for pH, alkalinity, hardness, total dissolved solutes, electrical conductivity, and salinity. Average values of the studied parameters were compared to determine if there were any statistically significant differences between the case and control areas. Results We observed that as many as 53.6% of the patients consumed <3 L of water daily. Analysis of drinking water samples from case and control areas, however, did not show any statistically significant alterations in the studied parameters. All water samples were found to be suitable for consumption. Conclusions It is not the quality of water, rather the quantity of water consumed that matters most in the occurrence of KSD. PMID:29744472

Management of obstructive calcular anuria with acute renal failure in children less than 4 years in age: a protocol for initial urinary drainage in relation to planned definitive stone management.

PubMed

ElSheemy, Mohammed S; Shoukry, Ahmed I; Shouman, Ahmed M; ElShenoufy, Ahmed; Aboulela, Waseem; Daw, Kareem; Hussein, Ahmed A; Morsi, Hany A

2014-12-01

To describe and evaluate our protocol for management of children≤4years old with obstructive calcular anuria (OCA) and acute renal failure (ARF) to improve selection of initial urinary drainage (ID) method and to facilitate subsequent definitive stone management (DSM) as studies discussing this special group of patients are still few. Patients with a contraindication to any method of ID were excluded. Decision (percutaneous nephrostomy (PCN) or double J (JJ) stent) was based on degree of hydronephrosis and planned DSM. We used 4.8-5Fr JJ or 6-8Fr PCN under general anesthesia and fluoroscopic guidance. According to our protocol, JJ is inserted for hydronephrosis≤grade 1. When the hydronephrosis is >grade 1, patients with radiolucent stones were treated by JJ whatever the site of the stone. When the stones were radiopaque, PCN was reserved for stones in a solitary functioning kidney and bilateral ureteric stones prepared for subsequent bilateral ureterolithotomy (or stone prepared for ureterolithotomy in a solitary kidney). After normalization of renal functions, DSM was staged attacking only one side before discharge. Both sides were cleared at the same session in cases with bilateral ureterolithotomy. Renal or ureteric stones suitable for SWL in a solitary kidney were treated with percutaneous nephrolithotripsy (PNL) or ureteroscopy. This was followed also in patients with bilateral stones suitable for SWL by clearing one side using ureteroscopy or PNL before discharge. Open surgery (OS) was reserved for cases with failed ureteroscopy or PNL, for ureteric stones>2.5 cm in size or very large volume complex renal stones. Stone free rate (SFR) was evaluated by CT. Our protocol was evaluated as regard recovery of renal functions, complications, and number of interventions to clear stones. This study included 62 boys and 22 girls presented with anuria for 1-4 days. JJ and PCN were inserted in 105 and 30 ureterorenal units (URU), respectively. Creatinine returns normal within 72 h. JJ insertion formed a part of DSM in 78/159 (49%) URU (stones prepared for extracorporeal shockwave lithotripsy or oral chemolytic dissolution therapy). PCN was the ideal tract for subsequent PNL in 11/159 (6.9%) URU. Accordingly, ID participated by 55.97% in DSM. Both operative and imaging times were slightly longer with PCN than JJ. There was no statistically significant difference in the insertion success or mean period to return to normal chemistry. Complications of both methods were mild and without any significant difference. Endourologic procedures constituted the majority of our interventions. Open surgical and endoscopic interventions for clearance of stones (including ID, treatment conversion and 2ry procedures) were done once for 25 patients, twice for 43 patients while it was needed three times for 16 patients. Total number of interventions was 149 procedures. SFR was 94%. Our protocol ensures adequate ID with minimal complications when using our selection criteria in children≤4 years in age with OCA and ARF. It also minimizes number of subsequent procedures to clear stones. Complications and success in insertion and drainage were equivalent in PCN and JJ groups. Copyright © 2014 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

[Identification and quantitation of purine derivatives in urinary calculi as markers of abnormal purine metabolism by using high-performance liquid chromatography (HPLC)].

PubMed

Safranow, K

2000-01-01

The objective of this study was to develop a practical method for the analysis of purine derivatives in urinary calculi using high-performance liquid chromatography (HPLC). The method presented herein includes extraction of purine derivatives from urinary stones, followed by chromatography on a reversed-phase column with UV detection. A simpler isocratic method was applied to quantitate 6 purines known to be components of urinary stones, namely uric acid, xanthine, hypoxanthine, 2,8-dihydroxyadenine, oxypurinol and allopurinol. Gradient method separated 10 additional peaks representing methyl derivatives of uric acid or xanthine (1-, 3-, 7-, and 9-methyluric acid, 1,3-,1,7-, and 3,7-dimethyluric acid, and 1-, 3-, and 7-methylxanthine) (Fig. 1). Detection limits for individual compounds ranged from 25 to 140 micrograms purine per g stone weight and precision (RSD%) was 0.5-2.4%. Both methods were next used to analyze purine derivatives in urinary calculi from 48 residents of Western Pomerania. Uric acid was the main component of 9 stones. All of the uric acid stones showed admixtures of 9 other purine derivatives: natural metabolites (hypoxanthine, xanthine, 2,8-dihydroxyadenine) and methyl derivatives of uric acid (1-,3-, and 7-methyluric acid, 1,3-dimethyluric acid, 3-, and 7-methylxanthine) originating from the metabolism of exogenous methylxanthines (caffeine, theophylline and theobromine) (Tab. 1,2). Methyl derivatives of uric acid and xanthine, with a maximal content in stones of 1.7%, have hitherto not been considered constituents of urinary calculi. Statistical analysis of the results revealed strong positive correlations between the level of uric acid and of other purine derivatives in stones (Fig. 2). Correlations were also found between levels of some purines and inorganic compounds (Tab. 3). The sensitivity and specificity of HPLC with UV detection satisfy the requirements of a reference method for the analysis of purines in urinary stones. Isocratic separation is simpler in terms of technique and equipment, and therefore more suitable for hospital laboratories. Examination of purine derivatives in stones may be very helpful for the diagnosis of abnormal purine metabolism and urolithiasis, particularly in dihydroxyadeninuria, xanthinuria and during treatment with allopurinol. Gradient separation requiring more sophisticated instrument seems useful for research purposes when the content of methyl derivatives of purines must be known. The present results indicate that urinary purines at concentrations lower than saturation point may nevertheless coprecipitate with oversaturated uric acid and appear as admixtures in urinary stones. The content of a purine derivative in stone depends on its average urinary excretion in the general population, similarity to the chemical structure of uric acid, and content of the latter in stone. These findings suggest that purines in stones represent a solid solution with uric acid as solvent. It is also plausible that methylxanthines, ubiquitous components of the diet and drugs, are involved in the pathogenesis of urolithiasis. Interpretation of results and practical significance of the determination of purine derivatives in stones is discussed, and future studies to assess the clinical importance of endo- and exogenous purine derivatives in urinary calculi are suggested.

Ureteric stents vs percutaneous nephrostomy for initial urinary drainage in children with obstructive anuria and acute renal failure due to ureteric calculi: a prospective, randomised study.

PubMed

ElSheemy, Mohammed S; Shouman, Ahmed M; Shoukry, Ahmed I; ElShenoufy, Ahmed; Aboulela, Waseem; Daw, Kareem; Hussein, Ahmed A; Morsi, Hany A; Badawy, Hesham

2015-03-01

To compare percutaneous nephrostomy (PCN) tube vs JJ ureteric stenting as the initial urinary drainage method in children with obstructive calcular anuria (OCA) and post-renal acute renal failure (ARF) due to bilateral ureteric calculi, to identify the selection criteria for the initial urinary drainage method that will improve urinary drainage, decrease complications and facilitate the subsequent definitive clearance of stones, as this comparison is lacking in the literature. A series of 90 children aged ≤12 years presenting with OCA and ARF due to bilateral ureteric calculi were included from March 2011 to September 2013 at Cairo University Pediatric Hospital in this randomised comparative study. Patients with grade 0-1 hydronephrosis, fever or pyonephrosis were excluded. No patient had any contraindication for either method of drainage. Stable patients (or patients stabilised by dialysis) were randomised (non-blinded, block randomisation, sealed envelope method) into PCN-tube or bilateral JJ-stent groups (45 patients for each group). Initial urinary drainage was performed under general anaesthesia and fluoroscopic guidance. We used 4.8-6 F JJ stents or 6-8 F PCN tubes. The primary outcomes were the safety and efficacy of both groups for the recovery of renal functions. Both groups were compared for operative and imaging times, complications, and the period required for a return to normal serum creatinine levels. The secondary outcomes included the number of subsequent interventions needed for clearance of stones. Additional analysis was done for factors affecting outcome within each group. All presented patients completed the study with intention-to-treat analysis. There was no significant difference between the PCN-tube and JJ-stent groups for the operative and imaging times, period for return to a normal creatinine level and failure of insertion. There were significantly more complications in the PCN-tube group. The stone size (>2 cm) was the only factor affecting the rates of mucosal complications, operative time and failure of insertion in the JJ-stent group. The degree of hydronephrosis significantly affected the operative time for PCN-tube insertion. Grade 2 hydronephrosis was associated with all cases of insertion failure in the PCN-tube group. The total number of subsequent interventions needed to clear stones was significantly higher in the PCN-tube group, especially in patients with bilateral stones destined for chemolytic dissolution (alkalinisation) or extracorporeal shockwave lithotripsy (ESWL). We recommend the use of JJ stents for initial urinary drainage for stones that will be subsequently treated with chemolytic dissolution or ESWL, as this will lower the total number of subsequent interventions needed to clear the stones. This is also true for stones destined for ureteroscopy (URS), as JJ-stent insertion will facilitate subsequent URS due to previous ureteric stenting. Mild hydronephrosis will prolong the operative time for PCN-tube insertion and may increase the incidence of insertion failure. We recommend the use of PCN tube if the stone size is >2 cm, as there was a greater risk of possible iatrogenic ureteric injury during stenting with these larger ureteric stones in addition to prolongation of operative time with an increased incidence of failure. © 2014 The Authors. BJU International © 2014 BJU International.

Rock riprap design for protection of stream channels near highway structures; Volume 2, Evaluation of Riprap design procedures

USGS Publications Warehouse

Blodgett, J.C.; McConaughy, C.E.

1986-01-01

In volume 2, seven procedures now being used for design of rock riprap installations were evaluated using data from 26 field sites. Four basic types of riprap failures were identified: Particle erosion, translational slide, modified slump, and slump. Factors associated with riprap failure include stone size , bank side slope, size gradation, thickness, insufficient toe or endwall, failure of the bank material, overtopping during floods, and geomorphic changes in the channel. A review of field data and the design procedures suggests that estimates of hydraulic forces acting on the boundary based on flow velocity rather than shear stress are more reliable. Several adjustments for local conditions, such as channel curvature, superelevation, or boundary roughness, may be unwarranted in view of the difficulty in estimating critical hydraulic forces for which the riprap is to be designed. Success of the riprap is related not only to the appropriate procedure for selecting stone size, but also to the reliability of estimated hydraulic and channel factors applicable to the site. (See also W89-04910) (Author 's abstract)

Safety and efficacy of silodosin and tadalafil in ease of negotiation of large ureteroscope in the management of ureteral stone: A prosective randomized trial

PubMed Central

Bhattar, Rohit; Jain, Vipin; Tomar, Vinay; Yadav, Sher Singh

2017-01-01

Objective To evaluate the safety and efficacy of silodosin and tadalafil in ease of negotiation of large size ureteroscope (8/9.8 Fr) in the management of ureteral stone. Material and methods Between June 2015 and May 2016, 86 patients presented with ureteral stone of size 6–15 mm were on consent randomly assigned to 1 of 3 outpatient treatment arms: silodosin (Group A), tadalafil (Group B), and placebo (Group C). After two weeks of therapy 67 patients underwent ureteroscopy, and ureteral orifice configuration, ureteroscopic negotiation, ureteral dilatation, operating time, procedural complication and drug related side effects were noted in each group. Results Ureteral negotiation was significantly better in Groups A (73.9%) and B (69.6%) as compared to Group C (38.1%) (p<0.01). Statistically significant difference was noted in the requirement for dilatation in Group C (71.4%) as compared to Groups A (26.1%) and B (39.1%) (p<0.01). Ureteral orifice was found to be more dilated in Groups A (69.6%) and B (60.9%) as compared to Group C (28.6%). Mean operating time was statistically lower in Groups A (35.2 min) and B (34.91 min) as compared to Group C (41.14 min) (p<0.01). Conclusion Both silodosin and tadalafil not only relax ureteral smooth muscle but also help in forward propagation of large size ureteroscope (8/9.8 Fr) without any significant risk of adverse events. PMID:29201512

Comparison of retrograde intrarenal surgery, shockwave lithotripsy, and percutaneous nephrolithotomy for treatment of medium-sized radiolucent renal stones.

PubMed

Resorlu, Berkan; Unsal, Ali; Ziypak, Tevfik; Diri, Akif; Atis, Gokhan; Guven, Selcuk; Sancaktutar, Ahmet Ali; Tepeler, Abdulkadir; Bozkurt, Omer Faruk; Oztuna, Derya

2013-12-01

To compare the outcomes of shock wave lithotripsy (SWL), percutaneous nephrolithotomy (PNL), and retrograde intrarenal surgery (RIRS) for 10-20 mm radiolucent renal calculi by evaluating stone-free rates and associated complications. A total of 437 patients at 7 institutions who underwent SWL (n = 251), PNL (n = 140), or RIRS (n = 46) were enrolled in our study. Clinical success was defined as stone-free status or asymptomatic insignificant residual fragments <3 mm. The success rates, auxiliary procedures, and complications were compared in each group. Success rates were 66.5, 91.4, and 87% for SWL, PNL, and RIRS (p < 0.001). The need for auxiliary procedures was more common after SWL than PNL and RIRS (21.9 vs 5.7 vs 8.7%, respectively; p < 0.001). The overall complication rates for the SWL, PNL, and RIRS were 7.6, 22.1, and 10.9%, respectively (p < 0.001). Thirteen patients in PNL group received blood transfusions, while none of the patients in RIRS and SWL groups transfused. Hospitalization time per patient was 1.3 ± 0.5 days in the RIRS group, while it was 2.6 ± 0.9 days in the PNL group (p < 0.001). Fluoroscopy and operation time were significantly longer in the PNL group compared to RIRS (145.7 ± 101.7 vs 28.7 ± 18.7 s, and 57.5 ± 22.1 vs 43.1 ± 17 min, respectively). For treatment of moderate-sized radiolucent renal stones, RIRS and PNL provide significantly higher success and lower retreatment rate compared with SWL. Although PNL is effective, its biggest drawback is its invasiveness. Blood loss, radiation exposure, hospital stay, and morbidities of PNL can be significantly reduced with RIRS technique.

Clinical Significance of Prostatic Calculi: A Review

PubMed Central

2018-01-01

Prostatic calculi often occur in middle-aged and old men. Prostatic calculi are usually classified as primary/endogenous stones or secondary/extrinsic stones. Endogenous stones are commonly caused by obstruction of the prostatic ducts around the enlarged prostate by benign prostatic hyperplasia (BPH) or by chronic inflammation. Extrinsic stones occur mainly around the urethra, because they are caused by urine reflux. The exact prevalence of prostatic calculi is not known, and it has been reported to vary widely, from 7% to 70%. Most cases of prostatic calculi are not accompanied by symptoms. Therefore, most cases are found incidentally during the diagnosis of BPH using transrectal ultrasonography (TRUS). However, prostatic calculi associated with chronic prostatitis may be accompanied by chronic pelvic pain. Rare cases have been reported in which extrinsic prostatic calculi caused by urine reflux have led to voiding difficulty due to their size. More than 80% of prostatic calculi are composed of calcium phosphate. Prostatic calculi can be easily diagnosed using TRUS or computed tomography. Treatment is often unnecessary, but if an individual experiences difficulty in urination or chronic pain, prostatic calculi can be easily removed using a transurethral electroresection loop or holmium laser. PMID:29076299

Early stone technology on Flores and its implications for Homo floresiensis.

PubMed

Brumm, Adam; Aziz, Fachroel; van den Bergh, Gert D; Morwood, Michael J; Moore, Mark W; Kurniawan, Iwan; Hobbs, Douglas R; Fullagar, Richard

2006-06-01

In the Soa Basin of central Flores, eastern Indonesia, stratified archaeological sites, including Mata Menge, Boa Lesa and Kobatuwa (Fig. 1), contain stone artefacts associated with the fossilized remains of Stegodon florensis, Komodo dragon, rat and various other taxa. These sites have been dated to 840-700 kyr bp (thousand years before present). The authenticity of the Soa Basin artefacts and their provenance have been demonstrated by previous work, but to quell lingering doubts, here we describe the context, attributes and production modes of 507 artefacts excavated at Mata Menge. We also note specific similarities, and apparent technological continuity, between the Mata Menge stone artefacts and those excavated from Late Pleistocene levels at Liang Bua cave, 50 km to the west. The latter artefacts, dated to between 95-74 and 12 kyr ago, are associated with the remains of a dwarfed descendent of S. florensis, Komodo dragon, rat and a small-bodied hominin species, Homo floresiensis, which had a brain size of about 400 cubic centimetres. The Mata Menge evidence negates claims that stone artefacts associated with H. floresiensis are so complex that they must have been made by modern humans (Homo sapiens).

Simulation of root forms using cellular automata model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Winarno, Nanang, E-mail: nanang-winarno@upi.edu; Prima, Eka Cahya; Afifah, Ratih Mega Ayu

This research aims to produce a simulation program for root forms using cellular automata model. Stephen Wolfram in his book entitled “A New Kind of Science” discusses the formation rules based on the statistical analysis. In accordance with Stephen Wolfram’s investigation, the research will develop a basic idea of computer program using Delphi 7 programming language. To best of our knowledge, there is no previous research developing a simulation describing root forms using the cellular automata model compared to the natural root form with the presence of stone addition as the disturbance. The result shows that (1) the simulation usedmore » four rules comparing results of the program towards the natural photographs and each rule had shown different root forms; (2) the stone disturbances prevent the root growth and the multiplication of root forms had been successfully modeled. Therefore, this research had added some stones, which have size of 120 cells placed randomly in the soil. Like in nature, stones cannot be penetrated by plant roots. The result showed that it is very likely to further develop the program of simulating root forms by 50 variations.« less

Primary endoscopic treatment of ureteric calculi. A review of 378 cases.

PubMed

Puppo, P; Ricciotti, G; Bozzo, W; Introini, C

1999-01-01

In the post-ESWL period, ureteroscopy represented the solution giving a second choice in the treatment of ureteral calculi in case of failure of extracorporeal lithotripsy. The aim of this study is to review a wide series of ureteral stones in which ureteroscopy combined with endoscopic lithotripsy can be chosen as the first approach for the treatment of ureteral calculi. Between January 1994 and September 1997, 378 patients underwent ureteroscopy and endoscopic lithotripsy for ureteral stones with a miniscope associated with either a pneumatic or electropneumatic lithotriptor. Three different miniscopes were used: Olympus (8 Fr), Wolf (7 Fr) and Circon Acmi (7.7 Fr). 238 patients were male and 140 were female. The stones were localized in the upper tract of the ureter in 62 cases (16.4%), 96 (25.3%) in the mid ureter and 220 (58. 3%) in the lower ureter. A complete stone fragmentation with spontaneous expulsion of the fragments occurred in 354 patients (93.6%). In 22 patients (5.8%) the stones were accidentally pushed up and successfully underwent ESWL. In 38 patients (10%) the fragments were completely removed by basket. A single J polyethylene catheter was placed in 21 (5.5%) and a JJ stent in 147 patients (38. 8%). The operative time ranged from 10 to 60 min, with an average time span of 32. In 22 cases (5.8%) an iterative ureteroscopy for stenosis or incomplete fragmentation was needed. Five cases (1.3%) of ureteral perforation were successfully treated by JJ stent, and only 1 case of ureteral avulsion (upper ureter) was treated by open surgery. In the attempt of overcoming an ureteral stenosis, we had 1 case (0.2%) of ureteral reimplantation. One patient (0.2%) underwent ureterolithotomy for an extremely narrow stenosis just before the ureteropelvic junction. No relevant complication was recorded in the postoperative period. Patients were dismissed after 1- 4 days (average 1.9). Up until now, no case of postoperative ureteral stricture has been observed, although we were not able to carry out a specific follow-up in all our patients. Ureteroscopy with miniscopes has a high success rate (93.6%) with low morbidity and can be given as a primary approach in the management of ureteral calculi. In the lumbar ureter (especially in women) this technique can represent a good alternative to ESWL in the treatment of obstructing stones (which need stenting) or when the patient asks for a 'one-shot' treatment.

The importance of source area mapping for rockfall hazard analysis

NASA Astrophysics Data System (ADS)

Valagussa, Andrea; Frattini, Paolo; Crosta, Giovanni B.

2013-04-01

A problem in the characterization of the area affected by rockfall is the correct source areas definition. Different positions or different size of the source areas along a cliff result in different possibilities of propagation and diverse interaction with passive countermeasures present in the area. Through the use of Hy-Stone (Crosta et al., 2004), a code able to perform 3D numerical modeling of rockfall processes, different types of source areas were tested on a case study slope along the western flank of the Mt. de La Saxe (Courmayeur, AO), developing between 1200 and 2055 m s.l.m. The first set of source areas consists of unstable rock masses identified on the basis of field survey and Terrestrial Laser Scanning (IMAGEO, 2011). A second set of source areas has been identified by using different thresholds of slope gradient. We tested slope thresholds between 50° and 75° at 5° intervals. The third source area dataset has been generating by performing a kinematic stability analysis. For this analysis, we mapped the join sets along the rocky cliff by means of the software COLTOP 3D (Jaboyedoff, 2004), and then we identified the portions of rocky cliff where planar/wedge and toppling failures are possible assuming an average friction angle of 35°. Through the outputs of the Hy-Stone models we extracted and analyzed the kinetic energy, height of fly and velocity of the blocks falling along the rocky cliff in order to compare the controls of different source areas. We observed strong variations of kinetic energy and fly height among the different models, especially when using unstable masses identified through Terrestrial Laser Scanning. This is mainly related to the size of the blocks identified as susceptible to failure. On the contrary, the slope gradient thresholds does not have a strong impact on rockfall propagation. This contribution highlights the importance of a careful and appropriate mapping of rockfall source area for rockfall hazard analysis and the design of passive countermeasures.

Obesity might not be a disadvantage for SWL treatment in children with renal stone.

PubMed

Akça, Oktay; Horuz, Rahim; Boz, Mustafa Yücel; Kafkasli, Alper; Gökhan, Okan; Göktaş, Cemal; Sarica, Kemal

2013-02-01

Although the management of urinary stones in obese patients is a challenge and the impact of the patient-related parameter has been well studied in adults: No study has evaluated the possible impact of obesity in terms of body mass index related SWL success in pediatric population. In this present study, we aimed to evaluate the safety and efficiency of SWL in obese children in a comparative manner with the cases in normal BMI value limits. A total of 66 children (45 boys and 21 girls, M/F:2.1) with renal calculi were treated with SWL. Depending on the BMI values, the children were divided into two groups as; Group 1 (n:50) children with normal BMI values (mean: 16.1) and Group 2 (n:16) obese children with higher BMI values (mean: 20.3). The success rates, complications, and need for auxiliary procedures after SWL were evaluated between two groups of patients in a comparative manner. While majority of the cases were treated under general anesthesia (n:61), a limited number of cases were treated under neurolept anesthesia with PiezoLith 3000 (Richard Wolf GmbH) lithotripter. Evaluation of efficiency was based on radiological examinations using abdominal radiography, ultrasonography, or CT scan when needed. Both the mean age and mean stone size values were similar in both groups. While the mean age was 62 months (24-148) in Group 1, this value was 68 months (24-137) in Group 2. Again mean stone size was 10.26 mm(5-25 mm) in Group 1 and 10.12 mm (6-20 mm) in Group 2. The mean number of SWL sessions and the number of SW's applied were similar in both groups (2.06 vs. 2.0 and 1975 vs. 1835, respectively). Evaluation of success rates after 3-months again did not show any statistically significant difference with respect to stone-free rates in both groups (47/50-94 %, 16/16-100 %, respectively). However, 3 children in Group 1 did show residual fragments (≤3 mm) which were followed closely with regular visits without any problem. In another 3 cases, again fragments migrated to involved ureter after lithotripsy and these fragments were successfully treated in situ with further SWL. With respect to auxiliary procedures, there was no specific procedure has been done in Group 2, but 3 cases did undergo further SWL for ureteral stones in Group 1. Stone location did not affect the final outcome of the procedure in a significant manner in both groups. Lastly, no serious complication could be demonstrated in both groups either during or after SWL procedures. In the light of the successful treatment outcomes with limited need for auxiliary procedures in both groups, we may say that obesity might not be a disadvantage for SWL in children with renal stones.

Treatment for residual stones using flexible ureteroscopy and holmium laser lithotripsy after the management of complex calculi with single-tract percutaneous nephrolithotomy.

PubMed

Chen, L; Sha, M-L; Li, D; Zhuo, J; Jiang, C-Y; Zhu, Y-P; Xia, S-J; Lu, J; Shao, Y

2017-04-01

This study validated the effectiveness and safety of the treatment for residual stones using flexible ureteroscopy (fURS) and holmium laser (0.6-1.2 J, 20-30 Hz) lithotripsy via a fiber with a 200-μm core diameter and 0.22 numerical aperture (NA) after the management of complex calculi with single-tract percutaneous nephrolithotomy (PCNL). Between January 2014 and June 2016, 27 consecutive patients with complex calculi underwent fURS and holmium laser lithotripsy after a planned single-tract PCNL. Among the 27 patients with complex calculi, 9 had full staghorn calculi, 7 had partial staghorn calculi, and 11 had multiple calculi. After the first single-tract PCNL session, the mean stone size and mean stone surface area were 18.0 ± 10.7 mm and 181.9 ± 172.2 mm 2 , respectively. Treatment for residual stones with fURS and holmium laser lithotripsy was successfully completed and was performed without intraoperative complications. The mean operative time of the fURS procedure was 69.1 ± 23.6 min, and the mean hospital stay was 5.3 ± 2.4 days. The mean decrease in the hemoglobin level was 7.3 ± 6.5 g/l. After the fURS procedure, the overall stone-free rate was 88.9%. The overall postoperative complication rate was 14.8% (Clavien grade I 11.1%; Clavien grade II 3.7%). The current approach tested here combines the advantages of both PCNL and fURS and effectively manages complex calculi with a high stone-free rate (SFR) (88.9%). This approach also reduced the number of treatment sessions, the number of percutaneous access tracts, and the blood loss and potential morbidity associated with multiple tracts.

Use of flexible ureteroscopy in the clinical practice for the treatment of renal stones: results from a large European survey conducted by the EAU Young Academic Urologists-Working Party on Endourology and Urolithiasis.

PubMed

Sanguedolce, F; Liatsikos, E; Verze, P; Hruby, S; Breda, A; Beatty, J D; Knoll, T

2014-08-01

Treatment of renal stones using flexible ureteroscopy (fURS) is increasingly common despite the poor evidence in literature supporting its use and indications. With this study, we wanted to investigate the current use and indication of fURS for the treatment of renal stones in the clinical practice across the European countries. A survey was conducted using an emailed questionnaire consisting of 21 items; 2,894 recipients were selected via the EAU membership database. The questionnaires were collected through the SurveyMonkey system and the data were processed with the SPSS statistical package. Frequencies, cross tabs and Pearson correlation coefficients were applied as appropriate. 1,168 questionnaires were collected (response rate 40.4%). fURS was performed in 72.9% of the respondents' institutions, and 54.2% of the respondents were performing the procedure. For 95% of the users, fURS was considered first-line treatment, for stone of lower pole stone (45.9%) and <1 cm (44.2%) and 2 cm (43.8%) in size. The ureteral access sheaths were used routinely by more than 70% of the respondents. Lower pole stone repositioning technique was routinely performed by 45.9% of the surgeons. After fragmentation, 47.2% of the responders preferred to retrieve only the bigger fragments. At the end of fURS, lower volume surgeons were more likely to place routinely a double-J stent (p = 0.001). Higher volume surgeons estimated a higher durability of devices, both optical and digital ones (p < 0.001), and were more prone to consider fURS cost-effective when compared to other treatment modalities (p < 0.001). fURS is widely used for the treatment of renal stones and its use and indication can vary according to the age and surgeons' case volume. Higher volume surgeons are more prompt to extend international guidelines indications and to consider the technology cost-effective.

Evaporative moisture loss from heterogeneous stone: Material-environment interactions during drying

NASA Astrophysics Data System (ADS)

McAllister, Daniel; Warke, Patricia; McCabe, Stephen; Gomez-Heras, M.

2016-11-01

The complexities of evaporation from structurally and mineralogically heterogeneous sandstone (Locharbriggs Sandstone) are investigated through a laboratory-based experiment in which a variety of environmental conditions are simulated. Data reported demonstrate the significance of material-environment interactions on the spatial and temporal variability of evaporative dynamics. Evaporation from porous stone is determined by the interplay between environmental, material and solution properties, which govern the rate and mode by which water is transmitted to, and subsequently removed from, an evaporating surface. Initially, when the stone is saturated, evaporation is characterized by high rates of moisture loss primarily controlled by external atmospheric conditions. However, as drying progresses, eventually the hydraulic continuity between the stone surface and subsurface is disrupted with recession of the drying front and a decrease in evaporation rates which become reliant on the ability of the material to transport water vapour to the block surface. Pore size distribution and connectivity, as well as other material properties, control the timing of each stage of evaporation and the nature of the transition. These experimental data highlight the complexity of evaporation, demonstrating that different regions of the same stone can exhibit varying moisture dynamics during drying and that the rate and nature of evaporative loss differs under different environmental conditions. The results identify the importance of material-environment interactions during drying and that stone micro-environmental conditions cannot be inferred from ambient data alone. These data have significance for understanding the spatial distribution of stone surface weathering-related morphologies in both the natural and built environments where mineralogical and/or structural heterogeneity creates differences in moisture flux and hence variable drying rates. Such differences may provide a clearer explanation for the initiation and subsequent development of complex weathering responses where areas of significant deterioration can be found alongside areas that exhibit little or no evidence of surface breakdown.

Optimal Settings for the Noncontact Holmium:YAG Stone Fragmentation Popcorn Technique.

PubMed

Emiliani, Esteban; Talso, Michele; Cho, Sung-Yong; Baghdadi, Mohammed; Mahmoud, Sadam; Pinheiro, Hugo; Traxer, Olivier

2017-09-01

The purpose of this study was to evaluate the popcorn technique using a wide range of holmium laser settings and fiber sizes in a systematic in vitro assessment. Evaluations were done with 4 artificial stones in a collection tube. A fixed ureteroscope was inserted through a ureteral access sheath to provide constant irrigation flow and the laser was placed 1 mm from the bottom. Combinations of 0.5 to 1.5 J, 10 to 20 and 40 Hz, and long and short pulses were tested for 2 and 4 minutes. We used 273 and 365 μm laser fibers. All tests were repeated 3 times. The stones were weighed before and after the experiments to evaluate the setting efficiency. Significant predictors of a highly efficient technique were assessed. A total of 144 tests were performed. Mean starting weight of the stones was 0.23 gm, which was consistent among the groups. After the experiment the median weight difference was 0.07 gm (range 0.01 to 0.24). When designating a 50% reduction in stone volume as the threshold indicating high efficiency, the significant predictors of an efficient popcorn technique were a long pulse (OR 2.7, 95% CI 1.05-7.15), a longer duration (OR 11.4, 95% CI 3.88-33.29), a small (273 μm) laser fiber (OR 0.23, 95% CI 0.08-0.70) and higher power (W) (OR 1.14, 95% CI 1.09-1.20). Higher energy, a longer pulse, frequencies higher than 10 Hz, a longer duration and a smaller laser fiber predict a popcorn technique that is more efficient at reducing stone volume. Copyright © 2017 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Shock Wave Injury to the Kidney in SWL: Review and Perspective

NASA Astrophysics Data System (ADS)

McAteer, James A.; Evan, Andrew P.; Willis, Lynn R.; Connors, Bret A.; Williams, James C.; Pishchalnikov, Yuri A.; Lingeman, James E.

2007-04-01

Shock wave lithotripsy (SWL) is a first-line option for treatment for urinary calculi—particularly effective for the removal of uncomplicated stones from the upper urinary tract. The success of lithotripsy is tempered, however, by the occurrence of acute injury that has been reported to progress to long-term complications. SW trauma to the kidney is a vascular lesion characterized by parenchymal and subcapsular bleeding. The acute lesion is dose-dependent, and typically localized to the focal volume of the lithotripter. Cavitation has been implicated in vessel rupture, but SW-shear has the potential to be a primary mechanism for damage as well. Possible chronic adverse effects of SWL may include new-onset hypertension, development of diabetes, and exacerbation of stone disease. If acute trauma could be reduced, it seems likely that serious long-term effects could be minimized, or even eliminated. Reducing the dose of SW's needed for stone breakage is one option. Improved coupling improves stone breakage, and slowing SW rate significantly improves stone-free outcomes. Experiments with animals now show that treatment protocols can be designed to protect against tissue injury. Initiating treatment with low energy SW's dramatically reduces lesion size, and reducing the rate of SW delivery virtually eliminates SW trauma altogether. SWL stands to gain from new advances in technology, as lithotripters become safer and more effective. Perhaps the greatest progress will be made when we have determined the physical mechanisms of SW action both for stone breakage and tissue damage, and have better characterized the biological response to SW's—as this will provide the principles needed to achieve the best combination of safety and efficiency with whatever lithotripter is at hand.

[Sialoendoscopy-assisted sialolithectomy for large parotid stones].

PubMed

Zhao, Jian; Zhang, Lei; Liu, Deng-gao; Zhang, Zu-yan; Yu, Guang-yan

2014-02-18

To explore the clinical application of endoscope-assisted operative retrieval of large parotid stones as a minimally invasive alternative. From January 2010 to April 2013, 6 patients (male: 5, female: 1, age from 30-62 years, and median age: 49.5 years)suffering from recurred swelling of parotid gland due to sialoliths were treated by endoscope-assisted parotid surgery in Peking University School and Hospital of Stomatology. All of the patients underwent clinical, ultrasonographic and cone-beam CT (CBCT) examinations to get the detailed information of the number, location and size of stones, which was recorded in the medical records. endoscope-assisted parotid surgery was performed under general anesthesia in all the 6 cases after the failure of basket or forcep retrieval firstly. During the operation, sialoendoscope was used to locate the stone exactly and then the calculus was exposed through a pre-auricular approach and released by incising the duct. The postoperative complications were recorded and observed during the follow-up periods. Preoperative radiological examinations showed that all of the sialoliths were near the hilum of parotid gland ducts in the 6 cases, which were 5-9 mm in diameter. All of the stones were removed successfully by endoscope-assisted operative retrieval. The incisions healed smoothly in all the 6 cases. There were no cases of facial nerve weakness, infection or salivary fistula. After a mean follow-up of 19 months (ranging from 6-36 months), 5 patients remained asymptomatic and 1 patient had mild obstructed or infective symptoms. The final results were satisfied. It is suggested that endoscope-assisted operative retrieval is a viable minimally invasive alternative to remove the large or recalcitrant parotid stones with a high successful rate and low complications.

Evidence for prosauropod dinosaur gastroliths in the Bull Run Formation (Upper Triassic, Norian) of Virginia

USGS Publications Warehouse

Weems, Robert E.; Culp, Michelle J.; Wings, Oliver

2007-01-01

Definitive criteria for distinguishing gastroliths from sedimentary clasts are lacking for many depositional settings, and many reported occurrences of gastroliths either cannot be verified or have been refuted. We discuss four occurrences of gastrolith-like stones (category 6 exoliths) not found within skeletal remains from the Upper Triassic Bull Run Formation of northern Virginia, USA. Despite their lack of obvious skeletal association, the most parsimonious explanation for several characteristics of these stones is their prolonged residence in the gastric mills of large animals. These characteristics include 1) typical gastrolith microscopic surface texture, 2) evidence of pervasive surface wear on many of these stones that has secondarily removed variable amounts of thick weathering rinds typically found on these stones, and 3) a width/length-ratio modal peak for these stones that is more strongly developed than in any population of fluvial or fanglomerate stones of any age found in this region. When taken together, these properties of the stones can be explained most parsimoniously by animal ingestion and gastric-mill abrasion. The size of these stones indicates the animals that swallowed them were large, and the best candidate is a prosauropod dinosaur, possibly an ancestor of the Early Jurassic gastrolith-producing prosauropod Massospondylus or Ammosaurus.Skeletal evidence for Upper Triassic prosauropods is lacking in the Newark Supergroup basins; footprints (Agrestipus hottoni and Eubrontes isp.) from the Bull Run Formation in the Culpeper basin previously ascribed to prosauropods are now known to be underprints (Brachychirotherium parvum) of an aetosaur and underprints (Kayentapus minor) of a ceratosaur. The absence of prosauropod skeletal remains or footprints in all but the uppermost (upper Rhaetian) Triassic rocks of the Newark Supergroup is puzzling because prosauropod remains are abundant elsewhere in the world in Upper Triassic (Carnian, Norian, and lower Rhaetian) continental strata. The apparent scarcity of prosauropods in Upper Triassic strata of the Newark Supergroup is interpreted as an artifact of ecological partitioning, created by the habitat range and dietary preferences of phytosaurs and by the preservational biases at that time within the lithofacies of the Newark Supergroup basins.

A special terpene combination (Rowatinex®) improves stone clearance after extracorporeal shockwave lithotripsy in urolithiasis patients: results of a placebo-controlled randomised controlled trial.

PubMed

Romics, Imre; Siller, György; Kohnen, Ralf; Mavrogenis, Stelios; Varga, József; Holman, Endre

2011-01-01

To investigate the safety and efficacy of a special terpene combination in the treatment of patients with urolithiasis after extracorporeal shockwave lithotripsy (ESWL). 222 patients with clinically stable kidney or ureter stones of 0.3-2.0 cm undergoing complication-free ESWL were randomised to receive a special terpene combination (Rowatinex®; 3 × 2 capsules/day) or placebo. The study consisted of a 12-week active treatment phase and a 2-week follow-up phase. All patients had a physical examination, and diagnosis of kidney stones was made by X-ray, intravenous pyelogram or ultrasound at weeks 1, 4, 8 and 12 as well as after 2 weeks of follow-up. Stone-free status was defined as obviously successful expulsion of calculi/fragments, being without any stone. In all, when compared to placebo, significantly more patients receiving the terpene combination treatment in the intent-to-treat (ITT) group [72 (67.9%) vs. 49 (50.0%); p = 0.0009] and the per-protocol (PP) group [69 (78.4%) vs. 48 (52.2%); p = 0.0004] were stone-free at the end of the study. Treatment with the terpene combination was also more effective when analysed with respect to the size of the treated stone. In addition, treatment with the terpene combination significantly reduced the median time to stone-free status from 85.0 to 56.0 days (p = 0.0061) and from 85.0 to 49.5 days (p = 0.0028) in the ITT and PP populations, respectively. Nine mild-to-moderate adverse events (AE; terpene combination group: 7 AE in 4 patients; placebo group: 2 AE in 2 patients) were assessed as drug-related. Treatment with the terpene combination is well tolerated and safe. The terpene combination was found to be an efficacious treatment in eliminating calculi fragments generated by ESWL as compared to placebo. The pharmacodynamic properties of the terpene combination (antilithogenic, antibacterial, antiinflammatory, spasmolytic and analgesic effects), which have been also confirmed in preclinical studies, represent a valuable alternative to the different drugs used in the treatment of urolithiasis. Copyright © 2010 S. Karger AG, Basel.

Ureteroscopy is more cost effective than shock wave lithotripsy for stone treatment: systematic review and meta-analysis.

PubMed

Geraghty, Robert M; Jones, Patrick; Herrmann, Thomas R W; Aboumarzouk, Omar; Somani, Bhaskar K

2018-05-05

A rising incidence of kidney stone disease has led to an increase in ureteroscopy (URS) and shock wave lithotripsy (SWL). Our aim was to compare the cost of URS and SWL for treatment of stones. A systematic review and meta-analysis based on Cochrane and PRISMA standards was conducted for all studies reporting on comparative cost of treatment between URS and SWL. The cost calculation was based on factual data presented in the individual studies as reported by the authors. English language articles from January 2001 to December 2017 using Medline, PubMed, EMBASE, CINAHL, Cochrane library and Google Scholar were selected. Our study was registered with PROSPERO (International prospective register of systematic reviews)-registration number CRD 42017080350. A total of 12 studies involving 2012 patients (SWL-1243, URS-769) were included after initial identification and screening of 725 studies with further assessment of 27 papers. The mean stone size was 10 and 11 mm for SWL and URS, respectively, with stone location in the proximal ureter (n = 8 studies), distal ureter (n = 1), all locations in the ureter (n = 1) and in the kidney (n = 2). Stone free rates (84 vs. 60%) were favourable for URS compared to SWL (p < 0.001). Complication rates (23 vs. 30%) were non-significantly in favor of SWL (p = 0.11) whereas re-treatment rates (11 vs. 27%) were non-significantly in favor of URS (p = 0.29). Mean overall cost was significantly lower for URS ($2801) compared to SWL ($3627) (p = 0.03). The included studies had high risk of bias overall. On sub-analysis, URS was significantly cost-effective for both stones  < 10 and  ≥ 10 mm and for proximal ureteric stones. There is limited evidence to suggest that URS is less expensive than SWL. However, due to lack of standardization, studies seem to be contradictory and further randomized studies are needed to address this issue.

Thulium fiber laser induced vapor bubbles using bare, tapered, ball, hollow steel, and muzzle brake fiber optic tips

NASA Astrophysics Data System (ADS)

Gonzalez, David A.; Hardy, Luke A.; Hutchens, Thomas C.; Irby, Pierce B.; Fried, Nathaniel M.

2018-02-01

This study characterizes laser-induced vapor bubbles for five distal fiber optic tip configurations, to provide insight into stone retropulsion experienced during laser ablation of kidney stones. A TFL with 1908-nm wavelength delivered 34 mJ energy per pulse at 500-μs pulse duration through five different fibers: 100-μm-core/170-μm-OD bare fiber tip, 150-μm- to 300-μm-core tapered fiber tip, 100-μm-core/300-μm-OD ball tip fiber, 100-μm-core/340- μm-OD hollow steel tip fiber, and 100-μm-core/560-μm-OD muzzle brake fiber tip. A high speed camera with 10- μm spatial and 9.5-μs temporal resolution imaged vapor bubble dynamics. A needle hydrophone measured pressure transients in forward (0°) and side (90°) directions while placed at a 6.8 +/- 0.4 mm distance from fiber tip. Maximum bubble dimensions (width/length) averaged 0.7/1.5, 1.0/1.6, 0.5/1.1, 0.8/1.9, and 0.7/1.5 mm, for bare, tapered, ball, hollow steel, and muzzle tips, respectively (n=5). The hollow steel tip exhibited the most elongated vapor bubble shape, translating into increased forward pressure in this study and consistent with higher stone retropulsion in previous reports. Relative pressures (a.u.) in (forward/side) directions averaged 1.7/1.6, 2.0/2.0, 1.4/1.2, 6.8/1.1, and 0.3/1.2, for each fiber tip (n=5). For hollow steel tip, forward pressure was 4× higher than for bare fiber. For the muzzle brake fiber tip, forward pressure was 5× lower than for bare fiber. Bubble dimensions and pressure measurements demonstrated that the muzzle tip reduced forward pressure by partially venting vapors through side holes, consistent with lower stone retropulsion observed in previous reports.

Neoinfundibulotomy for the management of symptomatic caliceal diverticula.

PubMed

Auge, Brian K; Munver, Ravi; Kourambas, John; Newman, Glenn E; Wu, Ning Z; Preminger, Glenn M

2002-04-01

Direct percutaneous access provides effective treatment for complex caliceal diverticula. Yet, access into the diverticulum alone is usually tenuous and passage of a guide wire across a stenotic infundibulum is often impossible. An alternative technique is described which creates a "neoinfundibulum" to assist in the management of symptomatic caliceal diverticula. During a 6-year period 22 patients with symptomatic caliceal diverticula were treated via a percutaneous approach, of whom 21 had calculi within the diverticula. After accessing the diverticulum directly, it was impossible to pass a guide wire through the stenotic infundibulum in 18 (82%) patients, prompting advancement of the access needle through the diverticular wall into the renal pelvis. Once secure access was established, balloon dilation was performed to 30Fr to create the "neoinfundibulum." Percutaneous ultrasonic lithotripsy was performed in the usual fashion. A 22Fr Councill catheter was placed to keep the infundibular tract open for 5 to 7 days to allow complete epithelialization and drainage. Stone-free, symptom-free and complication rates were assessed. Pain, recurrent urinary tract infections and hematuria were the presenting complaints in the subgroup of patients undergoing "neoinfundibulotomy." Average stone burden was 11.7 x 12 mm. and average hospital stay was 2.8 days. Of the patients 94% were symptom-free at 6-week followup, and 80% were stone-free on followup excretory urography. The remaining patients had residual stone fragments less than 3 mm. in diameter. Complications related to access were identified in 2 patients who sustained a pneumothorax after a supra-11th rib access, which was successfully managed with tube thoracostomy. Percutaneous management of complex caliceal diverticula provides a safe and effective option for symptomatic patients. When the stenotic infundibulum cannot be traversed with a guide wire, creation of a new infundibulum offers a secure alternative for accessing the collecting system, while providing equally effective results.

Chemically and size-resolved particulate matter dry deposition on stone and surrogate surfaces inside and outside the low emission zone of Milan: application of a newly developed "Deposition Box".

PubMed

Ferrero, Luca; Casati, Marco; Nobili, Lara; D'Angelo, Luca; Rovelli, Grazia; Sangiorgi, Giorgia; Rizzi, Cristiana; Perrone, Maria Grazia; Sansonetti, Antonio; Conti, Claudia; Bolzacchini, Ezio; Bernardi, Elena; Vassura, Ivano

2018-04-01

The collection of atmospheric particles on not-filtering substrates via dry deposition, and the subsequent study of the particle-induced material decay, is trivial due to the high number of variables simultaneously acting on the investigated surface. This work reports seasonally resolved data of chemical composition and size distribution of particulate matter deposed on stone and surrogate surfaces obtained using a new method, especially developed at this purpose. A "Deposition Box" was designed allowing the particulate matter dry deposition to occur selectively removing, at the same time, variables that can mask the effect of airborne particles on material decay. A pitched roof avoided rainfall and wind variability; a standardised gentle air exchange rate ensured a continuous "sampling" of ambient air leaving unchanged the sampled particle size distribution and, at the same time, leaving quite calm condition inside the box, allowing the deposition to occur. Thus, the "Deposition Box" represents an affordable tool that can be used complementary to traditional exposure systems. With this system, several exposure campaigns, involving investigated stone materials (ISMs) (Carrara Marble, Botticino limestone, Noto calcarenite and Granite) and surrogate (Quartz, PTFE, and Aluminium) substrates, have been performed in two different sites placed in Milan (Italy) inside and outside the low emission zone. Deposition rates (30-90 μg cm -2  month -1 ) showed significant differences between sites and seasons, becoming less evident considering long-period exposures due to a positive feedback on the deposition induced by the deposited particles. Similarly, different stone substrates influenced the deposition rates too. The collected deposits have been observed with optical and scanning electron microscopes and analysed by ion chromatography. Ion deposition rates were similar in the two sites during winter, whereas it was greater outside the low emission zone during summer and considering the long-period exposure. The dimensional distribution of the collected deposits showed a significant presence of fine particles in agreement with deposition rate of the ionic fraction. The obtained results allowed to point out the role of the fine particles fraction and the importance of making seasonal studies.

Stone formation in the Middle Eastern Gulf States: A review.

PubMed

Robertson, William G

2012-09-01

To review the possible causes of the high incidence of urolithiasis in the oil-rich Gulf States. Data were extracted from published reports on the incidence of urolithiasis, affluence and diet in the Gulf States, various Western countries and China. There are strong relationships: (a) between the life-expectancy of stones in men and the Gross National Income (GNI) per capita of these countries; and (b) between the daily consumption of animal protein and GNI per capita. Together these data suggest that the occurrence of stones is proportional to the intake of animal protein, although they also indicate that there are additional factors that further increase the risk of urolithiasis in the populations of the Gulf. The consumption of oxalate in the Gulf is three times higher and that of calcium a half of what it is in Western countries. Thus, the average oxalate/calcium ratio in the intestines of the Gulf populations is five to six times higher than that in Western populations, leading to enteric hyperoxaluria and an increased risk of calcium-oxalate stone formation. The risk is further accentuated by the lower urine volumes, due to the hot, dry climate of the region, and lower excretions of citrate, from the highly acidic urine resulting from the high intake of animal protein. There is a high incidence of uric acid-containing stones from the acidic urine and the hyperuricosuria caused by the high intake of purine. The high incidence of urolithiasis in the Gulf is due to an adverse combination of dietary and environmental factors.

Radiation exposure of patient and surgeon in minimally invasive kidney stone surgery.

PubMed

Demirci, A; Raif Karabacak, O; Yalçınkaya, F; Yiğitbaşı, O; Aktaş, C

2016-05-01

Percutaneous nephrolithotomy (PNL) and retrograde intrarenal surgery (RIRS) are the standard treatments used in the endoscopic treatment of kidney stones depending on the location and the size of the stone. The purpose of the study was to show the radiation exposure difference between the minimally invasive techniques by synchronously measuring the amount of radiation the patients and the surgeon received in each session, which makes our study unique. This is a prospective study which included 20 patients who underwent PNL, and 45 patients who underwent RIRS in our clinic between June 2014 and October 2014. The surgeries were assessed by dividing them into three steps: step 1: the access sheath or ureter catheter placement, step 2: lithotripsy and collection of fragments, and step 3: DJ catheter or re-entry tube insertion. For the PNL and RIRS groups, mean stone sizes were 30mm (range 16-60), and 12mm (range 7-35); mean fluoroscopy times were 337s (range 200-679), and 37s (range 7-351); and total radiation exposures were 142mBq (44.7 to 221), and 4.4mBq (0.2 to 30) respectively. Fluoroscopy times and radiation exposures at each step were found to be higher in the PNL group compared to the RIRS group. When assessed in itself, the fluoroscopy time and radiation exposure were stable in RIRS, and the radiation exposure was the highest in step 1 and the lowest in step 3 in PNL. When assessed for the 19 PNL patients and the 12 RIRS patients who had stone sizes≥2cm, the fluoroscopy time in step 1, and the radiation exposure in steps 1 and 2 were found to be higher in the PNL group than the RIRS group (P<0.001). Although there is need for more prospective randomized studies, RIRS appears to be a viable alternate for PNL because it has short fluoroscopy time and the radiation exposure is low in every step. 4. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

A comparative, epidemiological study of acute renal colic presentations to emergency departments in Doha, Qatar, and Melbourne, Australia.

PubMed

Pathan, Sameer A; Mitra, Biswadev; Bhutta, Zain A; Qureshi, Isma; Spencer, Elle; Hameed, Asmaa A; Nadeem, Sana; Tahir, Ramsha; Anjum, Shahzad; Cameron, Peter A

2018-01-03

This study aimed to compare the epidemiology, clinical presentations, management, and outcomes of renal colic presentations in two major academic centers from geographically diverse populations: Qatar (a country in the Afro-Asian stone belt) and South-Eastern Australia (not within a stone belt). We undertook a retrospective cohort study of patients with renal colic who presented to the Hamad General Hospital Emergency Department (HGH-ED), Qatar, and The Alfred ED, Melbourne, Australia, during a period of 1 year from August 1, 2012, to July 31, 2013. Cases were identified using ICD-9-CM codes, and an electronic template was used to record the data on predefined clinical variables. A total of 12,223 from the HGH-ED and 384 from The Alfred ED were identified as renal colic presentations during the study period. The rate of renal colic presentations at the HGH-ED was 27.9 per 1000 ED visits compared to 6.7 per 1000 ED visits at The Alfred ED. Patients presenting to the HGH-ED were significantly younger [34.9 years (29.0-43.4) than The Alfred ED [48 years (37-60); P < 0.001]. The median stone size was larger in the HGH-ED group [6 (4-8) mm] versus The Alfred ED group [4 (3-6) mm, P < 0.001]. The intervention rate in the stone-positive population was significantly higher in the HGH-ED group as opposed to The Alfred ED group (38.7 versus 11.9%, P < 0.001). At the time of discharge, The Alfred ED group received fewer analgesic prescriptions (55.8 versus 83.5%, P < 0.001) and more tamsulosin prescriptions (25.3 versus 11.7%, P < 0.001). Renal colic presentations to the HGH-ED, Qatar, were younger, with larger stone size mostly located in the lower ureter, compared to The Alfred ED, Melbourne, Australia. The findings suggest that the benefits of treatment including medical expulsion therapy will vary between the two populations. Differences in epidemiology and patient mix should be considered while tailoring strategies for effective management of patients with renal colic in a given setting.

Comparison of the clinical efficacy and safety of retroperitoneal laparoscopic ureterolithotomy and ureteroscopic holmium laser lithotripsy in the treatment of obstructive upper ureteral calculi with concurrent urinary tract infections.

PubMed

Jiang, Jun-Tao; Li, Wei-Guo; Zhu, Yi-Ping; Sun, Wen-Lan; Zhao, Wei; Ruan, Yuan; Zhong, Chen; Wood, Kristofer; Wei, Hai-Bin; Xia, Shu-Jie; Sun, Xiao-Wen

2016-07-01

The aim of this study is to compare the clinical efficacy and safety of retroperitoneal laparoscopic ureterolithotomy (RPLU) and ureteroscopic holmium laser lithotripsy (UHLL) as two minimally invasive procedures in managing obstructive upper ureteral calculi with concurrent urinary tract infections (UTI). The retrospective study included 189 patients who underwent unilateral obstructive upper ureteral stones with concurrent UTI from January 2007 to November 2014 at our institution. Patients received RPLU (81 cases) or UHLL (108 cases). All patients received preoperative anti-infection treatment (indwelling ureteral stent and/or preoperative antibiotics). Collected data, including sex, age, stone size, success rate, operation duration, post-operation hospitalization time, and post-operation complications, were compared. All patients were followed up for more than 6 months after surgeries, and no ureterostenosis occurred. The study included 189 patients, 41 (21.7 %) females and 148 (78.3 %) males with a medium age of 52 years (range 22-81 years). All surgeries were successfully performed without conversion to open surgery. Stone size in the RPLU group was larger than that of the UHLL group (16.1 ± 1.4 vs. 10.4 ± 1.6 mm, P = 0.012). Operative duration (P = 0.009) and hospitalization time (P < 0.001) in the UHLL group were significantly shorter than those in the RPLU group, whereas stone clearance rate was significantly higher in the RPLU group (100 vs. 88.9 %, P = 0.002). Of note, postoperative fever was more common in patients treated with UHLL (15 cases) versus RPLU (4 cases) (13.9 vs. 4.9 %, P = 0.043). Moreover, in the UHLL group, three patients without a preoperative indwelling ureteral stent were complicated with sepsis, which was not seen in RPLU group. In our study, the safety and stone clearance rate of RPLU are better than those of UHLL in the treatment of unilateral upper ureteric calculi with concurrent UTI. Preoperative antibiotics and indwelling ureteral stent may reduce the risk of postoperative infections.

Renal function changes after percutaneous nephrolithotomy in patients with renal calculi with a solitary kidney compared to bilateral kidneys.

PubMed

Shi, Xiaolei; Peng, Yonghan; Li, Ling; Li, Xiao; Wang, Qi; Zhang, Wei; Dong, Hao; Shen, Rong; Lu, Chaoyue; Liu, Min; Gao, Xiaofeng; Sun, Yinghao

2018-05-26

To evaluate renal function changes and risk factors for acute kidney injury (AKI) after percutaneous nephrolithotomy (PCNL) in patients with renal calculi with a solitary kidney (SK) or normal bilateral kidneys (BKs). Between 2012 and 2016, 859 patients undergoing PCNL were retrospectively reviewed at Changhai Hospital. In all, 53 patients with a SK were paired with 53 patients with normal BKs via a propensity score-matched analysis. Data for the following variables were collected: age, sex, body mass index, stone size, distribution, operation time, perioperative outcomes, and complications. The complications were graded according to the modified Clavien-Dindo system. Univariable and multivariable logistic regression models were constructed to evaluate risk factors for predicting AKI. The SK and BKs groups were comparable in terms of age, sex ratio, stone size, stone location distribution, comorbidities, and American Society of Anesthesiologists Physical Status classification. The initial and final stone-free rates were comparable between the SK and BKs groups (initial: 52.83% vs 58.49%, P = 0.696; final: 84.91% vs 92.45%, P = 0.359). There was no difference between the two groups for complications, according to the Clavien-Dindo grades. The estimated glomerular filtration rate (eGFR) increased dramatically after the stone burden was immediately relieved, and during the 6-month follow-up eGFR was lower in the SK group compared with the BKs group. We found a modest improvement in renal function immediately after PCNL in the BKs group, and renal function gain was delayed in the SK group. Through logistic regression analysis, we discovered that a SK, preoperative creatinine and diabetes were independent risk factors for predicting AKI after PCNL. Considering the overall complication rates, PCNL is generally a safe procedure for treating renal calculi amongst patients with a SK or normal BKs. Follow-up renal function analysis showed a modest improvement in patients of both groups. Compared to patients with normal BKs, patients with a SK were more likely to develop AKI after PCNL. © 2018 The Authors BJU International © 2018 BJU International Published by John Wiley & Sons Ltd.

Recent advances in lithotripsy technology and treatment strategies: A systematic review update

PubMed Central

Elmansy, H.E.; Lingeman, J.E.

2017-01-01

Introduction Shock wave lithotripsy (SWL) is a well – established treatment option for urolithiasis. The technology of SWL has undergone significant changes in an attempt to better optimize the results while reducing failure rates. There are some important limitations that restrict the use of SWL. In this review, we aim to place these advantages and limitations in perspective, assess the current role of SWL, and discuss recent advances in lithotripsy technology and treatment strategies. Methods A comprehensive review was conducted to identify studies reporting outcomes on ESWL. We searched for literature (PubMed, Embase, Medline) that focused on the physics of shock waves, theories of stone disintegration, and studies on optimising shock wave application. Relevant articles in English published since 1980 were selected for inclusion. Results Efficacy has been shown to vary between lithotripters. To maximize stone fragmentation and reduce failure rates, many factors can be optimized. Factors to consider in proper patient selection include skin – to – stone distance and stone size. Careful attention to the rate of shock wave administration, proper coupling of the treatment head to the patient have important influences on the success of lithotripsy. Conclusion Proper selection of patients who are expected to respond well to SWL, as well as attention to the technical aspects of the procedure are the keys to SWL success. Studies aiming to determine the mechanisms of shock wave action in stone breakage have begun to suggest new treatment strategies to improve success rates and safety. PMID:27890653

Identification and cause of decay of building materials used in the architectural heritage of Bizerte city (Tunisia)

NASA Astrophysics Data System (ADS)

Zoghlami, Karima; Lopez-Arce, Paula; Navarro, Antonia; Zornoza-Indart, Ainara; Gómez, David

2017-04-01

Monuments and historical buildings of Bizerte show a disturbing state of degradation. In order to propose a compatible materials for the restauration works such as stone of substitution and restauration mortars, a geological context was analysed with the objectif to localize historical quarries accompanied by a sedimentological study to identify the exploited geological formations. Petrophysical and chemical caracterisation of both stone and mortars have been carried out. With the aim to determine the origin of the erosion and the degree of stone decay, a combination of micro-destructive and non-destructive techniques have been used on-site and in-lab. Moisture measurements, ultrasonic velocity propagation and water absorption by Karsten pipe test together with polarized light and fluorescence optical microscopy, mercury intrusion porosimetry and ion chromatography analyses were carried out to perform petrophysical characterization of stone samples and determination of soluble salts. For the characterization of mortars, granulometric study was performed to determine the nature of components and their grain size distribution. Thin sections of mortar samples were examined for the petrographical and mineralogical characterization. X-ray diffraction (XRD) analysis of finely pulverized samples was performed in order to identify the mineral crystalline phases of the mortars. Thermal analyses [thermogravimetry (TG)] were performed in order to determine the nature of the binder and its properties. Porosity was determined following UNE-EN 1936 (2007) standart test. Geological and petrographical study showed that historical buildings are essentially built with high porous bioclastic calcarenite partially cemented by calcite which is Würm in age and outcrops all along the northern coast of Bizerte where several historical quarries were identified. Occasionally, two other types of lithologies were used as building stones and they correspond to two varieties of oligocene sandstones (brown quartz-arenite cemented by iron oxide and ochre-green colored sandstone cemented by calcite) and an eocene white limestone corresponding to a fine-grained globigerine wackstone according to Dunham classification. Results of the petrophysical study show that small variations in the petrographic characteristics of the building geomaterials, such as type and degree of cementation, porous network configuration and presence or absence of soluble salts leads to differential stone weathering. Results of study's mortars show that original and restoration mortars have similar mineralogical composition but different grain size distribution and proportion of binder/agregats. They differ equally by the nature of raw materials as demonstrated by the thermal analyses. The study show that little variation of these parameters can affect the durability and the performance of mortars and can accelerate the degradation process of the building stones, especially the oligocene and eocene lithotypes.

Protection of obstetric dimensions in a small-bodied human sample.

PubMed

Kurki, Helen K

2007-08-01

In human females, the bony pelvis must find a balance between being small (narrow) for efficient bipedal locomotion, and being large to accommodate a relatively large newborn. It has been shown that within a given population, taller/larger-bodied women have larger pelvic canals. This study investigates whether in a population where small body size is the norm, pelvic geometry (size and shape), on average, shows accommodation to protect the obstetric canal. Osteometric data were collected from the pelves, femora, and clavicles (body size indicators) of adult skeletons representing a range of adult body size. Samples include Holocene Later Stone Age (LSA) foragers from southern Africa (n = 28 females, 31 males), Portuguese from the Coimbra-identified skeletal collection (CISC) (n = 40 females, 40 males) and European-Americans from the Hamann-Todd osteological collection (H-T) (n = 40 females, 40 males). Patterns of sexual dimorphism are similar in the samples. Univariate and multivariate analyses of raw and Mosimann shape-variables indicate that compared to the CISC and H-T females, the LSA females have relatively large midplane and outlet canal planes (particularly posterior and A-P lengths). The LSA males also follow this pattern, although with absolutely smaller pelves in multivariate space. The CISC females, who have equally small stature, but larger body mass, do not show the same type of pelvic canal size and shape accommodation. The results suggest that adaptive allometric modeling in at least some small-bodied populations protects the obstetric canal. These findings support the use of population-specific attributes in the clinical evaluation of obstetric risk. (c) 2007 Wiley-Liss, Inc.

Observations on Middle Stone Age human teeth from Klasies River Main Site, South Africa.

PubMed

Grine, Frederick E

2012-11-01

The human fossils, artefacts and faunal remains from the Middle Stone Age (MSA) deposits of Klasies River Main Site have featured prominently in discussions of the evolution of modern human morphology and the emergence of human behavioral modernity. Nearly 40 human fossils were uncovered by John Wymer's (1967-1968) excavations, and subsequent work by Hilary Deacon (1984-1995) has produced an additional dozen specimens. Many of the latter have been described, but most of the dental remains have been afforded only cursory mention and provisional identification. These specimens are documented here, and questions of individual association among some of the fossils from Wymer's excavations are also addressed. Three teeth provide the first indisputable evidence for juvenile individuals in the deposit. The proportion of juvenile to adult remains in the MSA levels at Klasies is notably lower than in other penecontemporaneous South African coastal MSA sites such as Die Kelders Cave 1 and Blombos Cave, where the proportion of juveniles is seemingly in closer keeping with coastal, geographically proximate Later Stone Age sites such as Oakhurst Shelter and Matjes River Cave. The sizes of most of the recently identified human teeth from Klasies seem to affirm at least one arguable aspect of morphometric modernity in the MSA at this site in the form of a tendency for tooth size reduction. Copyright © 2012 Elsevier Ltd. All rights reserved.

Combined use of flexible ureteroscopic lithotripsy with micro-percutaneous nephrolithotomy in pediatric multiple kidney stones.

PubMed

Li, Jun; Wang, Wenying; Du, Yuan; Tian, Ye

2018-03-28

We investigated the clinical value of treating pediatric multiple kidney stones with extensive distribution using flexible ureteroscopic lithotripsy (FUL) combined with micro-percutaneous nephrolithotomy (micro-PNL). In total, 21 pediatric patients with multiple renal calculi between May 2016 and June 2017 received FUL combined with micro-PNL. The group included 13 boys and eight girls; the patients' mean age was 3.8 years (range 1-8 years). The maximum stone diameter ranged from 1.0 to 1.5 cm. FUL was first performed in the lithotomy position to fragment stones that were located in the renal pelvis, and upper and mid-renal calyx. Patients were then moved to a prone position, and micro-PNL was performed to treat lower pole stones that could not be reached by the flexible ureteroscope during FUL. Percutaneous renal access to the lower calyx was achieved using a 4.8F "all-seeing needle" with ultrasound guidance, and stone fragmentation was performed with a 200-μm holmium laser at different settings to disintegrate 1- to 2-mm fragments. All 21 pediatric patients with multiple kidney stones underwent combined FUL and micro-PNL. The stone free rate (SFR) was 85.7% (18/21). The mean surgical time was 45 min (range 30-70 min). The mean volume of irrigation fluid used was 480 mL (range 300-1200 mL). The mean surgical time for FUL and micro-PNL was 31 min and 14 min, respectively, and the mean volume of fluid used for FUL and micro-PNL was 360 mL and 120 mL, respectively. According to the modified Clavien classification, grade 1 and 2 postoperative complications occurred in five and one patients, respectively. The mean decrease in the level of hemoglobin was 0.4 g/dL (0-0.7 g/dL), and no patients required a transfusion. The average hospital stay was 3 days (range 2-5 days). Combined FUL and micro-PNL is a safe, effective, and minimally invasive operation to remove multiple renal calculi with extensive distribution in children in selected cases. Copyright © 2018 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

Recovering Ancient Inscriptions by X-ray Fluorescence Imaging

NASA Astrophysics Data System (ADS)

Powers, Judson; Dimitrova, Nora; Huang, Rong; Smilgies, Detlef-M.; Bilderback, Don; Clinton, Kevin; Thorne, Robert

2006-03-01

For many ancient cultures including those of the Mediterranean, carved stone inscriptions provide our most detailed historical record. Over the ages the surfaces of many of these inscriptions have been eroded so that the original text can no longer be distinguished. A method that allowed at least partial recovery of this lost text would provide a major breakthrough for the study of these cultures. The scope of analytical techniques that can be applied to stone tablets is limited by their large size and weight. We have applied X-ray fluorescence imaging to study the text of ancient stone inscriptions [1]. This method allows the concentrations of trace elements, including those introduced during inscription and painting, to be measured and mapped. The images created in this way correspond exactly to the published text of the inscription, both when traces of letters are visible with the naked eye and when they are barely detectable. [1] J. Powers et al., Zeitschrift für Papyrologie und Epigraphik 152: 221-227 (2005).

Adsorption of gold ions from industrial wastewater using activated carbon derived from hard shell of apricot stones - an agricultural waste.

PubMed

Soleimani, Mansooreh; Kaghazchi, Tahereh

2008-09-01

In this study, hard shell of apricot stones was selected from agricultural solid wastes to prepare effective and low cost adsorbent for the gold separation from gold-plating wastewater. Different adsorption parameters like adsorbent dose, particle size of activated carbon, pH and agitation speed of mixing on the gold adsorption were studied. The results showed that under the optimum operating conditions, more than 98% of gold was adsorbed onto activated carbon after only 3h. The equilibrium adsorption data were well described by the Freundlich and Langmuir isotherms. Isotherms have been used to obtain thermodynamic parameters. Gold desorption studies were performed with aqueous solution mixture of sodium hydroxide and organic solvents at ambient temperatures. Quantitative recovery of gold ions is possible by this method. As hard shell of apricot stones is a discarded as waste from agricultural and food industries, the prepared activated carbon is expected to be an economical product for gold ion recovery from wastewater.

A vacuum-operated pore-water extractor for estuarine and freshwater sediments

USGS Publications Warehouse

Winger, Parley V.; Lasier, Peter J.

1991-01-01

A vacuum-operated pore-water extractor for estuarine and freshwater sediments was developed and constructed from a fused-glass air stone attached with aquarium airline tubing to a 30 or 60 cc polypropylene syringe. Pore water is extracted by inserting the air stone into the sediment and creating a vacuum by retracting and bracing the syringe plunger. A hand-operated vacuum pump attached to a filtration flask was also evaluated as an alternative vacuum source. The volume and time to extract pore water varies with the number of devices and the sediment particle size. Extraction time is longer for fine sediments than for sandy sediments. Four liters of sediment generally yield between 500 and 1,500 mL of pore water. The sediment that surrounds and accumulates on the air stone acts as a filter, and, except for the first few milliliters, the collected pore water is clear. Because there is no exposure to air or avenue for escape, volatile compounds andin situ characteristics are retained in the extracted pore water.

Table Talk: The Case for Collaboration

ERIC Educational Resources Information Center

Kaboolian, Linda

2006-01-01

According to Joe A. Stone of the University of Oregon, average students do better in classrooms with unionized teachers, but less able and more able students do not. While this particular assumption lacks empirical clarity, many administrators and school board members feel that it would be much easier to reform public education if teacher unions…

The Effects of Weather on Rapid Runway Repair. Volume 1

DTIC Science & Technology

1983-05-01

stress include chronic heat exhaustion, forms of tropical dermatosis , and renal stones. Interestingly, no chronic physiological failures resulting from...kcal/m2 /hr as described by Lowry), or 90 kcal/hr or 105 watts for the average adult male (with 1.8 m2 of body surface area). Normal work is expected

"Sticks and Stones": Masculinities and Conflict Spaces

ERIC Educational Resources Information Center

Tucker, Leigh Adams; Govender, Kaymarlin

2017-01-01

Drawing upon a post-structural ethnography of boys' constructions of gendered and sexual identities in one South African high school, this paper empirically seeks to theorise how 20 Grade 8 boys, identified as The Jokers, The Achievers, The Outcasts and The Average Ou's, simultaneously seek out spaces in male peer culture to cultivate, police and…

Calcium oxalate stone formation in the inner ear as a result of an Slc26a4 mutation.

PubMed

Dror, Amiel A; Politi, Yael; Shahin, Hashem; Lenz, Danielle R; Dossena, Silvia; Nofziger, Charity; Fuchs, Helmut; Hrabé de Angelis, Martin; Paulmichl, Markus; Weiner, Steve; Avraham, Karen B

2010-07-09

Calcium oxalate stone formation occurs under pathological conditions and accounts for more than 80% of all types of kidney stones. In the current study, we show for the first time that calcium oxalate stones are formed in the mouse inner ear of a genetic model for hearing loss and vestibular dysfunction in humans. The vestibular system within the inner ear is dependent on extracellular tiny calcium carbonate minerals for proper function. Thousands of these biominerals, known as otoconia, are associated with the utricle and saccule sensory maculae and are vital for mechanical stimulation of the sensory hair cells. We show that a missense mutation within the Slc26a4 gene abolishes the transport activity of its encoded protein, pendrin. As a consequence, dramatic changes in mineral composition, size, and shape occur within the utricle and saccule in a differential manner. Although abnormal giant carbonate minerals reside in the utricle at all ages, in the saccule, a gradual change in mineral composition leads to a formation of calcium oxalate in adult mice. By combining imaging and spectroscopy tools, we determined the profile of mineral composition and morphology at different time points. We propose a novel mechanism for the accumulation and aggregation of oxalate crystals in the inner ear.