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.

Direct peroral cholangioscopy using an ultraslim upper endoscope for management of residual stones after mechanical lithotripsy for retained common bile duct stones.

PubMed

Lee, Y N; Moon, J H; Choi, H J; Min, S K; Kim, H I; Lee, T H; Cho, Y D; Park, S-H; Kim, S-J

2012-09-01

The incidence of residual stones after mechanical lithotripsy for retained common bile duct (CBD) stones is relatively high. Peroral cholangioscopy using a mother-baby system may be useful for confirming complete extraction of stones, but has several limitations regarding routine use. We evaluated the role of direct peroral cholangioscopy (DPOC) using an ultraslim upper endoscope for the evaluation and removal of residual CBD stones after mechanical lithotripsy. From August 2006 to November 2010, 48 patients who had undergone mechanical lithotripsy for retained CBD stones with no evidence of filling defects in balloon cholangiography were recruited. The bile duct was inspected by DPOC after balloon cholangiography. Detected residual CBD stones were directly retrieved with a basket or balloon catheter under DPOC. The incidence of residual stones detected by DPOC, and the success rate of residual stone retrieval under DPOC were investigated. DPOC was successfully performed in 46 of the 48 patients (95.8%). Of these, 13 patients (28.3%) had residual CBD stones (mean number 1.4, range 1-3; mean diameter 4.5 mm, range 2.3-9.6). The residual stones were removed directly under DPOC in 11 of these patients (84.6%). There were no complications associated with DPOC or stone removal. DPOC using an ultraslim upper endoscope is a useful endoscopic procedure for the evaluation and extraction of residual stones after mechanical lithotripsy for retained CBD stones. © Georg Thieme Verlag KG Stuttgart · New York.

Is in vivo analysis of urinary stone composition feasible? Evaluation of an experimental setup of a Raman system coupled to commercial lithotripsy laser fibers.

PubMed

Miernik, Arkadiusz; Eilers, Yvan; Nuese, Christoph; Bolwien, Carsten; Lambrecht, Armin; Hesse, Albrecht; Rassweiler, Jens J; Schlager, Daniel; Wilhelm, Konrad; Wetterauer, Ulrich; Schoenthaler, Martin

2015-10-01

Raman spectroscopy allows immediate analysis of stone composition. In vivo stone analysis during endoscopic treatment may offer advantages concerning surgical strategy and metaphylaxis. Urinary stone components were evaluated utilizing an experimental setup of a Raman system coupled to commercial laser fibers. Samples of paracetamol (acetaminophen) and human urinary stones with known Raman spectra were analyzed using an experimental Raman system coupled to common commercial lithotripsy laser fibers (200 and 940 µm). Two different excitation lasers were used at wavelengths of 532 and 785 nm. Numerical aperture of the fibers, proportion of reflected light reaching the CCD chip, and integration times were calculated. Mathematical signal correction was performed. Both the laser beam profile and the quality of light reflected by the specimens were impaired significantly when used with commercial fibers. Acquired spectra could no longer be assigned to a specific stone composition. Subsequent measurements revealed a strong intrinsic fluorescence of the fibers and poor light acquisition properties leading to a significant decrease in the Raman signal in comparison with a free-beam setup. This was true for both investigated fiber diameters and both wavelengths. Microscopic examination showed highly irregular fiber tip surfaces (both new and used fibers). Our results propose that laser excitation and light acquisition properties of commercial lithotripsy fibers impair detectable Raman signals significantly in a fiber-coupled setting. This study provides essential physical and technological information for the development of an advanced fiber-coupled system able to be used for immediate stone analysis during endoscopic stone therapy.

Transurethral holmium-YAG laser lithotripsy for large symptomatic prostatic calculi: initial experience.

PubMed

Goyal, Neeraj Kumar; Goel, Apul; Sankhwar, Satyanarayan

2013-08-01

Symptomatic prostatic calculi are a rare clinical entity with wide range of management options, however, there is no agreement about the preferred method for treating these symptomatic calculi. In this study we describe our experience of transurethral management of symptomatic prostatic calculi using holmium-YAG laser lithotripsy. Patients with large, symptomatic prostatic stones managed by transurethral lithotripsy using holmium-YAG laser over 3-year duration were included in this retrospective study. Patients were evaluated for any underlying pathological condition and calculus load was determined by preoperative X-ray KUB film/CT scan. Urethrocystoscopy was performed using 30° cystoscope in lithotomy position under spinal anesthesia, followed by transurethral lithotripsy of prostatic calculi using a 550 μm laser fiber. Stone fragments were disintegrated using 100 W laser generators (VersaPulse PowerSuite 100 W, LUMENIS Surgical, CA). Larger stone fragments were retreived using Ellik's evacuator while smaller fragments got flushed under continuous irrigation. Five patients (median age 42 years) with large symptomatic prostatic calculi were operated using the described technique. Three patients had idiopathic stones while rest two had bulbar urethral stricture and neurogenic bladder, respectively. Median operative time was 62 min. All the patients were stone free at the end of procedure. Median duration of catheterization was 2 days. Significant improvement was observed in symptoms score and peak urinary flow and none of the patient had any complication. Transurethral management using holmium-YAG laser lithotripsy is a safe and highly effective, minimally invasive technique for managing symptomatic prostatic calculi of all sizes with no associated morbidity.

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.

[Influence of lithotripsy modalities on complication rate].

PubMed

Radulović, Slobodan; Milenković-Petronić, Dragica; Vuksanović, Aleksandar; Vavić, Bozo

2009-01-01

Localization of ureteric stones and difference in disintegration success are the most important factors in determining the first treatment approach for ureteric stones. The aim of our study was to evaluate the difference in complication rate between different ureteric stone litho-tripsy modalities. Two hundred sixty patients with ureteric stones were analyzed in a prospective bicentric study that lasted 1 year.The patients were divided into two groups: 1-120 patients who underwent ESWL (extracorporeal shockwave lithotripsy) treatment and II-140 patients who were treated endoscopically with ballistic lithotripsy. RESULTS Ureteroscopic lithotripsy of all pelvic and iliac stones was significantly more successful comparing to ESWL, while lumbar ureteric stone treatment with ureteroscopic lithotripsy was not significantly more successful than ESWL, except for lumbar stones larger than 100mm2 that were significantly better treated endoscopically. In the I group complications after lithotripsy were recorded in 64 (59.3%) and in the II group in 58 (42.0%) patients, meaning that complications were statistically significantly more frequent in the I than in the II group. In the II group complications were significantly more often recorded after treatment of proximal comparing to ureteric stones of other localizations, while in the I group complica-tions were significantly more often detected after treatment of impacted stones than in the II group. Being significantly successful comparing to ESWL, ureteric stone treatment with ureteroscopic lithotripsy should be considered as the first therapeutic option for all, especially impacted stones located in the iliac and pelvic ureteric portion. In spite of absent statistical difference in the success rate, ESWL should be chosen as the first treatment option in all cases of lumbar ureteric stones due to lower complication rate except for stones larger than 100mm2that should be primarily treated endoscopically.

Are we all doing it wrong? Influence of stripping and cleaving methods of laser fibers on laser lithotripsy performance.

PubMed

Kronenberg, Peter; Traxer, Olivier

2015-03-01

We assessed whether stripping and cleaving the laser fiber tip with specialized tools, namely laser fiber strippers, or ceramic or metal scissors, would influence lithotripsy performance. Laser fiber tips were stripped with a specialized laser fiber stripper or remained coated. The tips were then cleaved with metal or ceramic scissors. Laser lithotripsy experiments were performed with the 4 fiber tip combinations using an automated laser fragmentation testing system with artificial stones made of plaster of Paris or BegoStone Plus (Bego, Lincoln, Rhode Island). High frequency-low pulse energy (20 Hz and 0.5 J) and low frequency-high pulse energy (5 Hz and 2.0 J) settings were used for 30 seconds. Fissure width, depth and volume, and laser fiber tip photos were analyzed. Coated laser fiber tips always achieved significantly higher ablation volumes (sometimes greater than 50%) than stripped laser fiber tips (p <0.00001) regardless of cleaving scissor type, stone material or lithotripter setting. Coated fiber tips cleaved with metal scissors ablated as well as those cleaved with ceramic scissors (p = 0.16). However, stripped fibers were much less ablative when they were cut with metal scissors compared to ceramic scissors (p <0.00001). Harder stone material decreased ablation volume (p <0.00001). Low frequency-high pulse energy settings were an average of 3 times more ablative than high frequency-low pulse energy settings (p <0.00001). Stripping the fibers, a harder stone material and low frequency-high pulse energy settings were associated with increased fiber tip degradation. Coated laser fibers provided better lithotripsy performance and metal scissors were as good as ceramic scissors to cleave coated fibers. This knowledge may improve and simplify the way that laser lithotripsy procedures are done worldwide. Copyright © 2015 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Thulium fiber laser lithotripsy in an in vitro ureter model

NASA Astrophysics Data System (ADS)

Hardy, Luke A.; Wilson, Christopher R.; Irby, Pierce B.; Fried, Nathaniel M.

2014-12-01

Using a validated in vitro ureter model for laser lithotripsy, the performance of an experimental thulium fiber laser (TFL) was studied and compared to the clinical gold standard holmium:YAG laser. The holmium laser (λ=2120 nm) was operated with standard parameters of 600 mJ, 350 μs, 6 Hz, and 270-μm-core optical fiber. The TFL (λ=1908 nm) was operated with 35 mJ, 500 μs, 150 to 500 Hz, and a 100-μm-core fiber. Urinary stones (60% calcium oxalate monohydrate/40% calcium phosphate) of uniform mass and diameter (4 to 5 mm) were laser ablated with fibers through a flexible video-ureteroscope under saline irrigation with flow rates of 22.7 and 13.7 ml/min for the TFL and holmium laser, respectively. The temperature 3 mm from the tube's center and 1 mm above the mesh sieve was measured by a thermocouple and recorded throughout each experiment for both lasers. Total laser and operation times were recorded once all stone fragments passed through a 1.5-mm sieve. The holmium laser time measured 167±41 s (n=12). TFL times measured 111±49, 39±11, and 23±4 s, for pulse rates of 150, 300, and 500 Hz, respectively (n=12 each). Mean peak saline irrigation temperatures reached 24±1°C for holmium, and 33±3°C, 33±7°C, and 39±6°C, for TFL at pulse rates of 150, 300, and 500 Hz, respectively. To avoid thermal buildup and provide a sufficient safety margin, TFL lithotripsy should be performed with pulse rates below 500 Hz and/or increased saline irrigation rates. The TFL rapidly fragmented kidney stones due in part to its high pulse rate, high power density, high average power, and observation of reduced stone retropulsion and may provide a clinical alternative to the conventional holmium laser for lithotripsy.

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.

Thermal Response to High-Power Holmium Laser Lithotripsy.

PubMed

Aldoukhi, Ali H; Ghani, Khurshid R; Hall, Timothy L; Roberts, William W

2017-12-01

The aim of this study was to investigate "caliceal" fluid temperature changes during holmium laser activation/lithotripsy using settings up to 40 W power output with different irrigation flow rates. The experimental system consisted of a glass test tube (diameter 10 mm/length 75 mm) filled with deionized water, to mimic a calix. Real-time temperature was recorded using a thermocouple (Physitemp, NJ) positioned 5 mm from the bottom of the tube. A 200 μm laser fiber (Flexiva; Boston Scientific, MA) was introduced through the working channel of a disposable ureteroscope (LithoVue; Boston Scientific) and the laser fiber tip was positioned 15 mm above the bottom of the test tube. Deionized water irrigation (room temperature) through the working channel of the ureteroscope was delivered at flow rates of 0, 7-8, 14-15, and 38-40 mL/minute. A 120-W holmium laser (pulse 120; Lumenis, CA) was used. The following settings were explored: 0.5 J × 10 Hz, 1.0 J × 10 Hz, 0.5 J × 20 Hz, 1.0 J × 20 Hz, 0.5 J × 40 Hz, 1.0 J × 40 Hz, and 0.5 J × 80 Hz. During each experiment, the laser was activated continuously for 60 seconds. Temperature increased with increasing laser power output and decreasing irrigation flow rate. The highest temperature, 70.3°C (standard deviation 2.7), occurred with laser setting of 1.0 J × 40 Hz and no irrigation after 60 seconds of continuous laser firing. None of the tested laser settings and irrigation parameters produced temperature exceeding 51°C when activated for only 10 seconds of continuous laser firing. High-power holmium settings fired in long bursts with low irrigation flow rates can generate high fluid temperatures in a laboratory "caliceal" model. Awareness of this risk allows urologist to implement a variety of techniques (higher irrigation flow rates, intermittent laser activation, and potentially cooled irrigation fluid) to control and mitigate thermal

Thulium fiber laser lithotripsy using a muzzle brake fiber tip

NASA Astrophysics Data System (ADS)

Hutchens, Thomas C.; Gonzalez, David A.; Irby, Pierce B.; Fried, Nathaniel M.

2017-02-01

The Thulium fiber laser (TFL) is being explored as an alternative to Holmium:YAG laser for lithotripsy. TFL beam profile allows coupling of higher power into smaller fibers than multimode Holmium laser beam, without proximal fiber tip degradation. A smaller fiber provides more space in ureteroscope working channel for increased saline irrigation and allows maximum ureteroscope flexion. However, distal fiber tip burnback increases as fiber diameter decreases. Previous studies utilizing hollow steel sheaths around recessed distal fiber tips reduced fiber burnback, but increased retropulsion. In this study, a "fiber muzzle brake" was tested for reducing fiber burnback and stone retropulsion. TFL lithotripsy studies were performed at 1908 nm, 35 mJ, 500 μs, and 300 Hz using a 100-μm-core fiber. The optimal stainless steel muzzle brake tip tested consisted of a 1-cm-long, 560-μm-OD, 360-μm-ID tube with 275-μm thru hole located 250-μm from the distal end. The fiber tip was recessed a distance of 500 μm. Stone phantom retropulsion, fiber tip burnback, and calcium oxalate stone ablation studies were performed, ex vivo. Small stones with a mass of 40 +/- 4 mg and 4-mm-diameter were ablated over a 1.5-mm sieve in 25 +/- 4 s (n=10), without distal fiber tip burnback. Reduction in stone phantom retropulsion distance by 50% and 85% was observed when using muzzle brake tips versus 100-μm-core bare fibers and hollow steel tip fibers. The muzzle brake fiber tip provided efficient stone ablation, reduced stone retropulsion, and minimal fiber degradation during TFL lithotripsy.

Use of pneumatic lithotripsy for managing difficult CBD calculi.

PubMed

Farooq Qadri, Syed Javid; Khan, Muneer; Khan, Naveed

2011-01-01

About 7-12% of patients who harbor gallbladder calculi concomitant common bile duct (CBD) calculi are present. The treatment of gallbladder calculi has standardized in the form of laparoscopic cholecystectomy but management of CBD calculi is still evolving. Endoscopic removal of CBD calculi <2 cm in diameter is successful in 90-100% of cases but patients harboring stones >2 cm in diameter high failure rates can be seen. Traditionally, laparoscopically one can achieve success rate comparable to endoscopic surgery but large and impacted calculi may cause failures. If one uses pneumatic lithotripsy during laparoscopic management of CBD calculi one can achieve 100% stone clearance irrespective of size, degree of hardness and impaction. This study evaluates the feasibility of using pneumatic lithotripsy for CBD calculi. To our knowledge this is the 1st reported series of using pneumatic lithotripsy for CBD calculi. From June 2002 to June 2010 96 laparoscopic CBD explorations (LCBDE) were done for CBD calculi. Patients having choledocholithiasis with CBD diameter of >10 mm were taken for LCBDE while in patients with CBD diameter of <10 mm were referred for endoscopic clearance. Additionally ERCP failure cases were also subjected to LCBDE. Rigid nephroscope was used for LCBDE and usually calculi were removed by forceps only. In patients having large, hard &/or impacted calculi pneumatic lithotripsy were used for fragmentation. Out of the 96 patients in 12 (12.5%) cases pneumatic lithotripsy was used for stone fragmentation. Out of these 12 cases 5 (41.6%) were ERCP failure cases. At a mean hospital stay of 2.5 days 100% stone clearance was achieved in all cases with no perioperative complication. The present study shows how successfully pneumatic lithotripsy can be used to fragment large, hard &/or impacted CBD calculi. Pneumatic lithotripsy being user friendly easily available can reliably fragment CBD calculi in one session. Copyright © 2010 Surgical Associates

Lasers in clinical urology: state of the art and new horizons.

PubMed

Marks, Andrew J; Teichman, Joel M H

2007-06-01

We present an overview of current and emerging lasers for Urology. We begin with an overview of the Holmium:YAG laser. The Ho:YAG laser is the gold standard lithotripsy modality for endoscopic lithotripsy, and compares favorably to standard electrocautery transurethral resection of the prostate for benign prostatic hyperplasia (BPH). Available laser technologies currently being studied include the frequency doubled double-pulse Nd:Yag (FREDDY) and high-powered potassium-titanyl-phosphate (KTP) lasers. The FREDDY laser presents an affordable and safe option for intracorporeal lithotripsy, but it does not fragment all stone compositions, and does not have soft tissue applications. The high power KTP laser shows promise in the ablative treatment of BPH. Initial experiments with the Erbium:YAG laser show it has improved efficiency of lithotripsy and more precise ablative and incisional properties compared to Ho:YAG, but the lack of adequate optical fibers limits its use in Urology. Thulium:YAG fiber lasers have also demonstrated tissue ablative and incision properties comparable to Ho:YAG. Lastly, compact size, portability, and low maintenance schedules of fiber lasers may allow them to shape the way lasers are used by urologists in the future.

Combining ultrasonography and noncontrast helical computerized tomography to evaluate Holmium laser lithotripsy

PubMed Central

Mi, Jia; Li, Jie; Zhang, Qinglu; Wang, Xing; Liu, Hongyu; Cao, Yanlu; Liu, Xiaoyan; Sun, Xiao; Shang, Mengmeng; Liu, Qing

2016-01-01

Abstract The purpose of the study was to establish a mathematical model for correlating the combination of ultrasonography and noncontrast helical computerized tomography (NCHCT) with the total energy of Holmium laser lithotripsy. In this study, from March 2013 to February 2014, 180 patients with single urinary calculus were examined using ultrasonography and NCHCT before Holmium laser lithotripsy. The calculus location and size, acoustic shadowing (AS) level, twinkling artifact intensity (TAI), and CT value were all documented. The total energy of lithotripsy (TEL) and the calculus composition were also recorded postoperatively. Data were analyzed using Spearman's rank correlation coefficient, with the SPSS 17.0 software package. Multiple linear regression was also used for further statistical analysis. A significant difference in the TEL was observed between renal calculi and ureteral calculi (r = –0.565, P < 0.001), and there was a strong correlation between the calculus size and the TEL (r = 0.675, P < 0.001). The difference in the TEL between the calculi with and without AS was highly significant (r = 0.325, P < 0.001). The CT value of the calculi was significantly correlated with the TEL (r = 0.386, P < 0.001). A correlation between the TAI and TEL was also observed (r = 0.391, P < 0.001). Multiple linear regression analysis revealed that the location, size, and TAI of the calculi were related to the TEL, and the location and size were statistically significant predictors (adjusted r2 = 0.498, P < 0.001). A mathematical model correlating the combination of ultrasonography and NCHCT with TEL was established; this model may provide a foundation to guide the use of energy in Holmium laser lithotripsy. The TEL can be estimated by the location, size, and TAI of the calculus. PMID:27930563

Endoscopic laser-urethroplasty

NASA Astrophysics Data System (ADS)

Gilbert, Peter

2006-02-01

The objective was to prove the advantage of endoscopic laser-urethroplasty over internal urethrotomy in acquired urethral strictures. Patients and Method: From January, 1996 to June, 2005, 35 patients with a mean age of 66 years were submitted to endoscopic laser-urethroplasty for strictures of either the bulbar (30) or membranous (5) urethra. The operations were carried out under general anesthesia. First of all, the strictures were incised at the 4, 8 and 12 o'clock position by means of a Sachse-urethrotom. Then the scar flap between the 4 and 8 o'clock position was vaporized using a Nd:YAG laser, wavelength 1060 nm and a 600 pm bare fiber, the latter always being in contact with the tissue. The laser worked at 40W power in continuous mode. The total energy averaged 2574 J. An indwelling catheter was kept in place overnight and the patients were discharged the following day. Urinalysis, uroflowmetry and clinical examination were performed at two months after surgery and from then on every six months. Results: No serious complications were encountered. Considering a mean follow-up of 18 months, the average peak flow improved from 7.3 ml/s preoperatively to 18.7 mVs postoperatively. The treatment faded in 5 patients ( 14.3% ) who finally underwent open urethroplasty. Conclusions: Endoscopic laser-urethroplasty yields better short-term results than internal visual urethrotomy. Long-term follow-up has yet to confirm its superiority in the treatment of acquired urethral strictures.

Intracorporeal lithotripsy. Update on technology.

PubMed

Zheng, W; Denstedt, J D

2000-05-01

The number and variety of devices currently available for endoscopic lithotripsy reflect the reality that no single device is ideal in all situations. Although the search for the universal lithotriptor continues, the urologist must consider several factors if faced with the decision of which device to purchase. Perhaps foremost among these factors is the clinical situation with which one commonly deals. For example, although the smaller, flexible probes such as EHL or laser demonstrate considerable utility if used ureteroscopically, the larger stone burden associated with today's percutaneous nephrolithotripsy population often is treated more efficiently with one of the mechanical devices employing a larger, rigid probe, such as ultrasound or the Lithoclast. Similarly, the type and size of endoscopic equipment at one's disposal have a significant impact on which device to purchase or use. There are physical constraints affecting which device may or may not be used, rigid versus flexible endoscope, working channel caliber, and offset versus end-on-port. The skill and experience of the surgeon is also a factor of obvious importance, particularly if one is using a modality with a relatively narrow margin of safety such as EHL. Likewise, the training and experience of nursing personnel is a factor, especially regarding the use of lasers, which require certified personnel who are well versed in laser safety. Finally, in today's environment one must carefully evaluate cost in terms of not only initial capital outlay but also ongoing charges for disposable and maintenance items. Thus, the decision of which device to purchase is complex and requires careful evaluation of all of the previously noted variables. Likewise, if one is fortunate enough to have more than one device available, the decision of which lithotriptor to employ requires a similar decision based on sound surgical judgment.

Use of the Moses Technology to Improve Holmium Laser Lithotripsy Outcomes: A Preclinical Study.

PubMed

Elhilali, Mostafa M; Badaan, Shadie; Ibrahim, Ahmed; Andonian, Sero

2017-06-01

To evaluate in vitro and in vivo effects of Moses technology in Holmium laser and to compare it with the Regular mode in terms of lithotripsy efficiency and laser-tissue interactions. The Lumenis ® Pulse™ P120H holmium laser system together with Moses D/F/L fibers were used to compare the Regular mode with the Moses modes in stone retropulsion by using a high-speed camera, and stone ablation efficiency. In addition, a porcine ureteroscopy model was used to assess stone fragmentation and dusting as well as laser-tissue interaction with the ureteral wall. After a laser pulse, in vitro stone displacement experiments showed a significant reduction in retropulsion when using the Moses mode. The stone movement was reduced by 50 times at 0.8 J and 10 Hz (p < 0.01). The pronounced reduction of retropulsion in the Moses mode was clearly observed during fragmentation setting (high energy) and dusting (low energy, high Hz). In addition, stone fragmentation tests showed that the Moses modes resulted in a significantly higher ablation volume when compared with the Regular mode (160% higher; p < 0.001). In vivo assessment also supported the reduction in retropulsion when treating stones in the porcine kidney. Histological analysis of the porcine ureter after direct lasing in the Moses mode suggested less damage than in the Regular mode. The Moses technology resulted in more efficient laser lithotripsy, in addition to significantly reduced stone retropulsion, and displayed a margin of safety that may result in a shorter procedural time and safer lithotripsy.

Further characterization of photothermal breakdown products of uric acid stones following holmium:YAG laser lithotripsy

NASA Astrophysics Data System (ADS)

Glickman, Randolph D.; Weintraub, Susan T.; Kumar, Neeru; Corbin, Nicole S.; Lesani, Omid; Teichman, Joel M. H.

2000-06-01

Previously we found that Ho:YAG laser (2120 nm) lithotripsy of uric acid stones produced cyanide, a known thermal breakdown product of uric acid. We now report that alloxan, another thermal breakdown product, is also likely produced. Uric acid stones (approximately 98% pure) of human origin were placed in distilled water and subjected to one of the following experimental treatments: unexposed control, exposed to Ho:YAG laser, Nd:YAG laser, or mechanically crushed. Samples were then processed for HPLC analysis with UV detection. Peaks were identified by comparison to authentic standards. All samples contained uric acid, with retention time (RT) about 6 min. All of the laser-exposed samples contained a peak that eluted at 2.5 min, identical to the RT of authentic alloxan. Ho:YAG laser irradiation, however, produced a larger presumed alloxan peak than did the Nd:YAG laser. The peak at 2.5 min, as well as unidentified later-eluting peaks, were present in the laser-exposed, but not the unexposed or mechanically crushed, samples. These results confirm the thermal nature of lithotripsy performed with long-pulse IR lasers.

Thermal effects of Ho: YAG laser lithotripsy: real-time evaluation in an in vitro model.

PubMed

Hein, Simon; Petzold, Ralf; Schoenthaler, Martin; Wetterauer, Ulrich; Miernik, Arkadiusz

2018-04-24

To evaluate the thermal effect of Ho:YAG laser lithotripsy in a standardized in vitro model via real-time temperature measurement. Our model comprised a 20 ml test tube simulating the renal pelvis that was immersed in a 37 °C water bath. Two different laser fibers [FlexiFib (15-45 W), RigiFib 1000 (45-100 W), LISA laser products OHG, Katlenburg-Lindau, Germany] were placed in the test tube. An Ho:YAG 100 W laser was used in all experiments (LISA). Each experiment involved 120 s of continuous laser application, and was repeated five times. Different laser settings (high vs. low frequency, high vs. low energy, and long vs. short pulse duration), irrigation rates (0 up to 100 ml/min, realized by several pumps), and human calcium oxalate stone samples were analyzed. Temperature data were acquired by a real-time data logger with thermocouples (PICO Technology, Cambridgeshire, UK). Real-time measurements were assessed using MatLab ® . Laser application with no irrigation results in a rapid increase in temperature up to ∆28 K, rising to 68 °C at 100 W. Low irrigation rates yield significantly higher temperature outcomes. Higher irrigation rates result immediately in a lower temperature rise. High irrigation rates of 100 ml/min result in a temperature rise of 5 K at the highest laser power setting (100 W). Ho:YAG laser lithotripsy might be safe provided that there is sufficient irrigation. However, high power and low irrigation resulted in potentially tissue-damaging temperatures. Laser devices should, therefore, always be applied in conjunction with continuous, closely monitored irrigation whenever performing Ho:YAG laser lithotripsy.

Differentiation of tissue and kidney stones for laser lithotripsy using different spectroscopic approaches

NASA Astrophysics Data System (ADS)

Lange, Birgit; Cordes, Jens; Brinkmann, Ralf

2015-07-01

Holmium lasers are nowadays the gold standard for endoscopic laser lithotripsy. However, there is a risk of damaging or perforating the ureter or kidney tissue when the vision is poor. An automatic tissue/stone differentiation would improve the handling and safety of the procedure. To achieve this objective, an easy and robust real-time discrimination method has to be found which can be used to realize a feedback loop to control the laser system. Two possible approaches have been evaluated: White light reflectance and fluorescence spectroscopy. In both cases, we use the treatment fiber for detection and evaluate the possibility to decide whether the fiber is placed in front of tissue or calculus by the signal that is delivered by the surface in front of it. White light reflectance spectroscopy uses the standard light source for endourologic surgeries: Radiation of a Xenon light source is coupled to the ureteroscope via a liquid light guide. The part of the white light that is reflected back into the fiber is spectroscopically analyzed. In a clinical proof of concept study reflection signals were measured in vivo in 8 patients. For differentiation of stone and tissue via autofluorescence, excitation as well as detection was done via the treatment fiber. A suitable excitation wavelength was chosen with in vitro measurements (UV / visible) on several human renal calculi and porcine tissues. For verification of the positive results with green excitation in a clinical proof of concept study, a measurement set-up was realized which allows the recording of fluorescence signals during an endourological intervention.

Proteus mirabilis viability after lithotripsy of struvite calculi

NASA Astrophysics Data System (ADS)

Prabakharan, Sabitha; Teichman, Joel M. H.; Spore, Scott S.; Sabanegh, Edmund; Glickman, Randolph D.; McLean, Robert J. C.

2000-05-01

Urinary calculi composed of struvite harbor urease-producing bacteria within the stone. The photothermal mechanism of holmium:YAG lithotripsy is uniquely different than other lithotripsy devices. We postulated that bacterial viability of struvite calculi would be less for calculi fragmented with holmium:YAG irradiation compared to other lithotripsy devices. Human calculi of known struvite composition (greater than 90% magnesium ammonium phosphate hexahydrate) were incubated with Proteus mirabilis. Calculi were fragmented with no lithotripsy (controls), or shock wave, intracorporeal ultrasonic, electrohydraulic, pneumatic, holmium:YAG or pulsed dye laser lithotripsy. After lithotripsy, stone fragments were sonicated and specimens were serially plated for 48 hours at 38 C. Bacterial counts and the rate of bacterial sterilization were compared. Median bacterial counts (colony forming units per ml) were 8 X 106 in controls and 3 X 106 in shock wave, 3 X 107 in ultrasonic, 4 X 105 in electrohydraulic, 8 X 106 in pneumatic, 5 X 104 in holmium:YAG and 1 X 106 in pulsed dye laser lithotripsy, p less than 0.001. The rate of bacterial sterilization was 50% for holmium:YAG lithotripsy treated stones versus 0% for each of the other cohorts, p less than 0.01. P. mirabilis viability is less after holmium:YAG irradiation compared to other lithotripsy devices.

Expanding endourology for biliary stone disease: the efficacy of intracorporeal lithotripsy on refractory biliary calculi.

PubMed

Sninsky, Brian C; Sehgal, Priyanka D; Hinshaw, J Louis; McDermott, John C; Nakada, Stephen Y

2014-07-01

We evaluated the efficacy of ureteroscopic therapy (electrohydraulic lithotripsy [EHL] and intraductal laser lithotripsy [ILL]) in patients with challenging biliary stones secondary to anatomic variations resulting from a previous surgical procedure, including liver transplantation. A retrospective chart review was performed for all patients with previous surgical alteration of the gastrointestinal (GI) tract who underwent EHL or ILL via peroral or percutaneous access for choledocholithiasis by a single surgeon at our institution from 2000 to 2012. A database containing clinical and surgical variables was created, and long-term follow-up was conducted (3-138 months; median, 99 months). Thirteen patients (51.7±20.0 years; M:F, 10:3) in whom endoscopic retrograde cholangiopancreatography (ERCP), percutaneous transhepatic cholangiography (PTHC), or both failed were identified. Failure of ERCP/PTHC was because of inaccessibility of the calculi in all cases. Stone clearance was achieved in 12/13 (93%) patients; 8/12 (62%) after one procedure, and 4/12 (31%) after two procedures. One patient with biliary cast syndrome needed four interventions over 9 years. Major complications were low, with only one patient with hypotension and cholangitis that resolved with 24 hours of administration of intravenous fluids and antibiotics. Both endoscopic and percutaneous lithotripsies are effective treatments for refractory biliary calculi resulting from the post-surgical GI tract. Although a staged second procedure may be necessary in patients with significant stone burden, this is significantly better than extensive open surgery.

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

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.

[Endoscopic extraction of gallbladder calculi].

PubMed

Kühner, W; Frimberger, E; Ottenjann, R

1984-06-29

Endoscopic extraction of gallbladder stones were performed, as far as we know for the first time, in three patients with combined choledochocystolithiasis. Following endoscopic papillotomy (EPT) and subsequent mechanical lithotripsy of multiple choledochal concrements measuring up to 3 cm the gallbladder stones were successfully extracted with a Dormia basket through the cystic duct. The patients have remained free of complications after the endoscopic intervention.

Cavitation bubble dynamics during thulium fiber laser lithotripsy

NASA Astrophysics Data System (ADS)

Hardy, Luke A.; Kennedy, Joshua D.; Wilson, Christopher R.; Irby, Pierce B.; Fried, Nathaniel M.

2016-02-01

The Thulium fiber laser (TFL) is being explored for lithotripsy. TFL parameters differ from standard Holmium:YAG laser in several ways, including smaller fiber delivery, more strongly absorbed wavelength, low pulse energy/high pulse rate operation, and more uniform temporal pulse structure. High speed imaging of cavitation bubbles was performed at 105,000 fps and 10 μm spatial resolution to determine influence of these laser parameters on bubble formation. TFL was operated at 1908 nm with pulse energies of 5-75 mJ, and pulse durations of 200-1000 μs, delivered through 100-μm-core fiber. Cavitation bubble dynamics using Holmium laser at 2100 nm with pulse energies of 200-1000 mJ and pulse duration of 350 μs was studied, for comparison. A single, 500 μs TFL pulse produced a bubble stream extending 1090 +/- 110 μm from fiber tip, and maximum bubble diameters averaged 590 +/- 20 μm (n=4). These observations are consistent with previous studies which reported TFL ablation stallout at working distances < 1.0 mm. TFL bubble dimensions were five times smaller than for Holmium laser due to lower pulse energy, higher water absorption coefficient, and smaller fiber diameter used.

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.

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

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.

Does stone entrapment with ″Uro-Net″ improve Ho:YAG laser lithotripsy efficiency in percutaneous nephrolithotomy and cystolithopaxy?: an in vitro study.

PubMed

Marchini, Giovanni Scala; Rai, Aayushi; De, Shubha; Sarkissian, Carl; Monga, Manoj

2013-01-01

to test the effect of stone entrapment on laser lithotripsy efficiency. Spherical stone phantoms were created using the BegoStone® plaster. Lithotripsy of one stone (1.0 g) per test jar was performed with Ho:YAG laser (365 µm fiber; 1 minute/trial). Four laser settings were tested: I-0.8 J,8 Hz; II-0.2J,50 Hz; III-0.5 J,50 Hz; IV-1.5 J,40 Hz. Uro-Net (US Endoscopy) deployment was used in 3/9 trials. Post-treatment, stone fragments were strained though a 1mm sieve; after a 7-day drying period fragments and unfragmented stone were weighed. Uro-Net nylon mesh and wire frame resistance were tested (laser fired for 30s). All nets used were evaluated for functionality and strength (compared to 10 new nets). Student's T test was used to compare the studied parameters; significance was set at p < 0.05. Laser settings I and II caused less damage to the net overall; the mesh and wire frame had worst injuries with setting IV; setting III had an intermediate outcome; 42% of nets were rendered unusable and excluded from strength analysis. There was no difference in mean strength between used functional nets and non-used devices (8.05 vs. 7.45 lbs, respectively; p = 0.14). Setting IV was the most efficient for lithotripsy (1.9 ± 0.6 mg/s; p < 0.001) with or without net stabilization; setting III was superior to I and II only if a net was not used. Laser lithotripsy is not optimized by stone entrapment with a net retrieval device which may be damaged by high energy laser settings.

Laser scanning endoscope for diagnostic medicine

NASA Astrophysics Data System (ADS)

Ouimette, Donald R.; Nudelman, Sol; Spackman, Thomas; Zaccheo, Scott

1990-07-01

A new type of endoscope is being developed which utilizes an optical raster scanning system for imaging through an endoscope. The optical raster scanner utilizes a high speed, multifaceted, rotating polygon mirror system for horizontal deflection, and a slower speed galvanometer driven mirror as the vertical deflection system. When used in combination, the optical raster scanner traces out a raster similar to an electron beam raster used in television systems. This flying spot of light can then be detected by various types of photosensitive detectors to generate a video image of the surface or scene being illuminated by the scanning beam. The optical raster scanner has been coupled to an endoscope. The raster is projected down the endoscope, thereby illuminating the object to be imaged at the distal end of the endoscope. Elemental photodetectors are placed at the distal or proximal end of the endoscope to detect the reflected illumination from the flying spot of light. This time sequenced signal is captured by an image processor for display and processing. This technique offers the possibility for very small diameter endoscopes since illumination channel requirements are eliminated. Using various lasers, very specific spectral selectivity can be achieved to optimum contrast of specific lesions of interest. Using several laser lines, or a white light source, with detectors of specific spectral response, multiple spectrally selected images can be acquired simultaneously. The potential for co-linear therapy delivery while imaging is also possible.

Holmium: YAG laser lithotripsy versus pneumatic lithotripsy for treatment of distal ureteral calculi: a meta-analysis.

PubMed

Yin, Xiangrui; Tang, Ziwei; Yu, Bei; Wang, Yarong; Li, Yuehua; Yang, Qi; Tang, Wei

2013-04-01

The objective of this study was to estimate the treatment effect of Pneumatic Lithotripsy (PL) versus holmium: YAG laser lithotripsy (LL) in the treatment of distal ureteric calculi. A bibliographic search covering the period from 1990 to April 2012 was conducted using search engines such as MEDLINE, EMBASE, and Cochrane library. Data were extracted and analyzed with RevMan5.1 software. A total of 47 studies were scant, and 4 independent studies were finally recruited. Holmium: YAG LL conveyed significant benefits compared with PL in terms of early stone-free rate [odds ratio (OR)=4.42, 95% confidence interval (CI) (1.14, 17.16), p=0.03], delayed stone-free rate [OR=4.42, 95%CI (1.58, 12.37), p=0.005], mean operative time [WMD=-16.86, 95%CI (-21.33, -12.39), p<0.00001], retaining double-J catheter rate [OR=0.44, 95%CI (0.25, 0.78), p=0.004], and stone migration incidence [OR=0.26, 95%CI (0.11, 0.62), p=0.003], but not yet in the postoperative hematuria rate and the ureteral perforation rate according to this meta-analysis. Precise estimates on larger sample size and trials of high quality may provide more uncovered outcomes in the future.

Extracorporeal shock wave lithotripsy in the treatment of ureteral lithiasis: methodological controversies and therapeutic efficacy.

PubMed

Zanetti, G; Seveso, M; Montanari, E; Guarneri, A; Rovera, F; Trinchieri, A

1996-09-01

The treatment of ureteral stones has undergone a radical change in the last 15 years. First, the increased use of endoscopic procedures and then the introduction of extracorporeal lithotripsy relegated traditional surgery to a marginal role for this type of disorder. The best available treatment modality for ureteral lithiasis, particularly distal ureteral stones, is still a matter of great controversy among urologist. With the introduction in clinical use of second- and third generation lithotripters, which are even less invasive and require no anesthesia, interest has increased in treating patients by extracorporeal lithotripsy, reducing endoscopic monoeuvres to a minimum. The absolute contraindications to extracorporeal lithotripsy for ureteral stones are the same as those for renal stones: intractable hemostatic alterations, pregnancy, physical structure that limits positioning and altered patency of the urinary tract. From June 1990 to December 1994, 270 patients with ureteral stones were treated by extracorporeal lithotripsy at our center. The Dornier MPL 9000 lithotripter was used in 68 cases (25%) and the modified HM3 Dornier in 202 (75%). Pretreatment manoeuvres were performed in 130 patients (48%). Endoscopic manoeuvres were not performed in 140 patients treated in situ. 18 patients (13%) treated initially in situ subsequently underwent post-treatment manoeuvres which were required only in 3 patients who had undergone pretreatment. All patients were examined as outpatients 3 months after the treatment. A total of 241 patients (89%) were stone free, 121 who had undergone pretreatment manoeuvres and 119 who had been treated in situ. 29 patients (11%) were not stone free: 23 patients subsequently underwent endoscopic lithotripsy, 2 surgery and 4 stone removal by Dormia probe. The possibility of performing treatment without anesthesia, the absence of complications and the high proportion of successes make extracorporeal lithotripsy, particularly the in situ

Endoscopic laser recanalisation of presaccal canalicular obstruction

PubMed Central

Kuchar, A.; Novak, P.; Pieh, S.; Fink, M.; Steinkogler, F. J.

1999-01-01

AIM—To document the results of erbium (Er)-YAG laser treatment in presaccal canalicular obstruction in combination with the use of a flexible endoscope.
METHODS—For the first time an Er-YAG laser (Schwind, Sklerostom) was attached to a flexible endoscope (Schwind, Endognost) and used to recanalise a stenosis of the upper, lower, or common canaliculus. In 17 patients (mean age 41.5 (SD 11.9) years), 19 treatments (two bilateral) were performed. In all cases the scar was observed using the endoscope and was excised by laser ablation. A silicone intubation was performed in all cases. In addition to the endoscopy an irrigation was performed to prove the intactness of the lacrimal pathway system after laser treatment.
RESULTS—Membranous obstructions with a maximum length of 2.0 mm (14 procedures) in the canaliculus were opened easily using the laser, and the silicone intubation was subsequently performed without difficulty. Scars thicker than 2.0 mm could not be opened safely without canaliculus penetration (five procedures). Irrigation was positive in all cases up to the end of a 6 month period, providing the tubes remained in place. The maximum follow up is now 17 months (minimum 8 months) and in 16 cases (84.2%) the canaliculi are still intact.
CONCLUSION—Endoscopic laser treatment combined with silicone intubation enables us to recanalise presaccal stenoses of canaliculi under local anaesthesia up to a scar thickness of 2.0 mm. Best results can be achieved in cases where much tissue can be saved. Under such conditions this procedure can substitute for more invasive surgical techniques, especially a conjunctivo-dacryocystorhinostomy (CDCR).

 Keywords: laser recanalisation; presaccal canalicular obstruction; endoscopy PMID:10434867

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.

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.

Endoscopic and interstitial Nd:YAG laser therapy to control duodenal and periampullary carcinoma

NASA Astrophysics Data System (ADS)

Barr, Hugh; Fowler, Aiden L.

1996-12-01

Duodenal and periampullary cancer present with jaundice, bleeding and obstruction. Many patients are unsuitable for radical surgery. Endoscopic palliation of jaundice can be achieved using endoscopic sphincterotomy or stent insertion. However, the problems of bleeding and obstruction can be difficult to manage. Ten patients were treated using superficial Nd:YAG laser ablation and lower power interstitial laser therapy. After initial outpatient endoscopic therapy, treatment was repeated at 4 monthly intervals to prevent recurrent symptoms. Bleeding was controlled in all patients and only one patient developed obstructive symptoms between treatment sessions. This responded to further endoscopic laser therapy. The median survival was 21 months. Laser treated patients were compared with a historical series of 22 patients treated with endoscopic sphincterotomy or stent insertion. The complication rate was less in patients treated with the laser.

Thulium fiber laser lithotripsy using tapered fibers.

PubMed

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

2010-01-01

The Thulium fiber laser has recently been tested as a potential alternative to the Holmium:YAG laser for lithotripsy. This study explores use of a short taper for expanding the Thulium fiber laser beam at the distal tip of a small-core fiber. Thulium fiber laser radiation with a wavelength of 1,908 nm, 10 Hz pulse rate, 70 mJ pulse energy, and 1-millisecond pulse duration was delivered through a 2-m-length fiber with 150-microm-core-input-end, 300-microm-core-output-end, and 5-mm-length taper, in contact with human uric acid (UA) and calcium oxalate monohydrate (COM) stones, ex vivo (n = 10 each). Stone mass loss, stone crater depths, fiber transmission losses, fiber burn-back, irrigation rates, and deflection through a flexible ureteroscope were measured for the tapered fiber and compared with conventional fibers. After delivery of 1,800 pulses through the tapered fiber, mass loss measured 12.7+/-2.6 mg for UA and 7.2+/-0.8 mg COM stones, comparable to conventional 100-microm-core fibers (12.6+/-2.5 mg for UA and 6.8+/-1.7 mg for COM stones). No transmission losses or burn-back occurred for the tapered fiber after 36,000 pulses, while a conventional 150-microm fiber experienced significant tip degradation after only 1,800 pulses. High irrigation rates were measured with the tapered fiber inserted through the working port of a flexible ureteroscope without hindering its deflection, mimicking that of a conventional 150 microm fiber. The short tapered distal fiber tip allows expansion of the laser beam, resulting in decreased fiber tip damage compared to conventional small-core fibers, without compromising fiber bending, stone vaporization efficiency, or irrigation rates.

Treatment of ureteral calculus obstruction with laser lithotripsy in an Atlantic bottlenose dolphin (Tursiops truncatus).

PubMed

Schmitt, Todd L; Sur, Roger L

2012-03-01

An adult female bottlenose dolphin (Tursiops truncatus) presented with acute anorexia secondary to progressive azotemia (blood urea nitrogen = 213 mg/dl, creatinine [Cr] = 9.5 mg/dl) and electrolyte abnormalities (K = 7.4 mEq/L). It was later diagnosed with postrenal obstruction secondary to bilaterally obstructing ureteral calculi seen on ultrasound. Treatment of the obstruction required two endoscopic procedures, cystoscopy for ureteral stent placement and ureteroscopy to perform intracorporeal lithotripsy on the obstructing calculi. Before the first procedure, the dolphin's azotemia was stabilized with aggressive fluid therapy, peritoneal dialysis, and treatment for acidosis. Diuresis subsequent to the fluid therapy enabled passage of the right obstructing urolith. For both endoscopic procedures, the dolphin was placed in left lateral recumbency due to the peritoneal dialysis catheter in the right retroperitoneal region. For the first procedure, a 12-French (Fr) flexible cystoscope was inserted retrograde into the bladder via the urethra, whereupon a calculus was seen obstructing the left ureteral orifice. A 4.8-Fr, 26-cm double-pigtail ureteral stent was placed up the left ureter to relieve the postrenal obstruction. Inadvertent proximal migration of the left ureteral stent occurred during the procedure. However, renal parameters (serum Cr = 5.8, K = 5.4) improved significantly by the next day. For the second procedure, 28 hr later, ureteroscopy was performed to treat the calculus and replace the existing stent with a longer stent. The left ureteral calculus was pulverized into tiny fragments by using a holmium:yttrium-aluminum-garnet laser inserted through a 6.9-Fr semirigid ureteroscope. The migrated stent was visualized in the distal left ureter and replaced with a 90-cm single-pigtail ureteral stent that was sutured exterior to the urogenital slit and removed 3 days later. Renal function normalized over the next several days, and the dolphin recovered over

In vitro fragmentation efficiency of holmium: yttrium-aluminum-garnet (YAG) laser lithotripsy--a comprehensive study encompassing different frequencies, pulse energies, total power levels and laser fibre diameters.

PubMed

Kronenberg, Peter; Traxer, Olivier

2014-08-01

To assess the fragmentation (ablation) efficiency of laser lithotripsy along a wide range of pulse energies, frequencies, power settings and different laser fibres, in particular to compare high- with low-frequency lithotripsy using a dynamic and innovative testing procedure free from any human interaction bias. An automated laser fragmentation testing system was developed. The unmoving laser fibres fired at the surface of an artificial stone while the stone was moved past at a constant velocity, thus creating a fissure. The lithotripter settings were 0.2-1.2 J pulse energies, 5-40 Hz frequencies, 4-20 W power levels, and 200 and 550 μm core laser fibres. Fissure width, depth, and volume were analysed and comparisons between laser settings, fibres and ablation rates were made. Low frequency-high pulse energy (LoFr-HiPE) settings were (up to six times) more ablative than high frequency-low pulse energy (HiFr-LoPE) at the same power levels (P < 0.001), as they produced deeper (P < 0.01) and wider (P < 0.001) fissures. There were linear correlations between pulse energy and fragmentation volume, fissure width, and fissure depth (all P < 0.001). Total power did not correlate with fragmentation measurements. Laser fibre diameter did not affect fragmentation volume (P = 0.81), except at very low pulse energies (0.2 J), where the large fibre was less efficient (P = 0.015). At the same total power level, LoFr-HiPE lithotripsy was most efficient. Pulse energy was the key variable that drove fragmentation efficiency. Attention must be paid to prevent the formation of time-consuming bulky debris and adapt the lithotripter settings to one's needs. As fibre diameter did not affect fragmentation efficiency, small fibres are preferable due to better scope irrigation and manoeuvrability. © 2013 The Authors. BJU International © 2013 BJU International.

High-Frequency Dusting Versus Conventional Holmium Laser Lithotripsy for Intrarenal and Ureteral Calculi.

PubMed

Li, Roger; Ruckle, David; Keheila, Mohamed; Maldonado, Jonathan; Lightfoot, Michelle; Alsyouf, Muhannad; Yeo, Alexander; Abourbih, Samuel R; Olgin, Gaudencio; Arenas, Javier L; Baldwin, D Duane

2017-03-01

The efficiency of holmium laser lithotripsy for urolithiasis depends upon several factors, including laser pulse energy and frequency and stone composition and retropulsion. This study investigates the complex interplay between these factors and quantifies lithotripsy efficiency using different laser settings in a benchtop kidney and ureter model. In vitro caliceal and ex vivo porcine ureteral models were constructed. Calcium oxalate monohydrate stones were fragmented using a 200-μm laser fiber. In the caliceal model, stone fragmentation and vaporization rates at settings of 0.6 J/5 Hz, 0.2 J/15 Hz, and 0.2 J/50 Hz were compared. In the ureteral model, fragmentation time, retropulsion rate, fragmentation rate, and fragmented stone weight were compared at settings of 0.6 J/5 Hz and 0.2 J/15 Hz. Retropulsive forces generated at 0.6 J/5 Hz, 0.2 J/15 Hz, and 0.2 J/50 Hz settings were compared. Analysis was performed using Student's t-test and one-way ANOVA. In the caliceal model, the 0.6 J/5 Hz setting fragmented and vaporized stones at a higher rate than the 0.2 J/15 Hz setting (0.072 vs. 0.049 mg/s; p < 0.001). However, when the 0.2 J energy setting was combined with the 50 Hz frequency, the fragmentation rate (0.069 mg/s) was similar to the fragmentation rate at 0.6 J/5 Hz (0.072 mg/s; p = 0.677). In the ureteral model, the 0.6 J/5 Hz setting produced higher fragmentation rates (0.089 vs. 0.049 mg/s; p < 0.001), but resulted in significantly lower fragmented stone weight overall (16.815 vs. 25.485 mg; p = 0.009) due to higher retropulsion rates (0.732 vs. 0.213 mm/s; p < 0.001). Retropulsive forces decreased significantly when pulse energy decreased from 0.6 to 0.2 J (0.907 vs. 0.223 N; p < 0.001). Frequency did not affect retropulsive force at 15 and 50 Hz settings (0.223 vs. 0.288 N; p = 0.509). Laser lithotripsy of calcium oxalate monohydrate stones in the ureter

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

Holmium: yttrium aluminum garnet laser-assisted endoscopic sinus surgery: laboratory experience.

PubMed

Shapshay, S M; Rebeiz, E E; Bohigian, R K; Hybels, R L; Aretz, H T; Pankratov, M M

1991-02-01

Endoscopic sinus surgery has gained wide acceptance since its introduction into the United States. Complex sinus anatomy and troublesome bleeding have been associated with complications, which vary in severity from synechia to blindness and leakage of cerebrospinal fluid. Endoscopic sinus surgery using a holmium: yttrium aluminum garnet pulsed solid-state laser oscillating at 2.1 microns with fiberoptic delivery was performed in the laboratory, and the results were compared with those of conventional endoscopic sinus surgery. Three beagle dogs, six human cadaver heads, and one calf head were used in the in vivo and in vitro studies to evaluate the bone ablation, tissue coagulation, and hemostatic properties of the holmium: yttrium aluminum garnet laser. Modified endoscopic telescopes for sinus surgery, a newly developed handpiece for fiberoptic delivery, and other surgical instruments were used. The results indicate that the holmium: yttrium aluminum garnet laser and new delivery instrumentation provide good hemostasis and controlled soft-tissue ablation and bone removal. The access to all sinuses in the human cadaver model was very good. The canine in vivo study showed delayed but complete healing on the laser-treated side. Clinical evaluation of the holmium: yttrium aluminum garnet laser is warranted to increase the precision and safety of endoscopic sinus surgery.

Kidney stone ablation times and peak saline temperatures during Holmium:YAG and Thulium fiber laser lithotripsy, in vitro, in a ureteral model

NASA Astrophysics Data System (ADS)

Hardy, Luke A.; Wilson, Christopher R.; Irby, Pierce B.; Fried, Nathaniel M.

2015-02-01

Using a validated in vitro ureter model for laser lithotripsy, the performance of an experimental Thulium fiber laser (TFL) was studied and compared to clinical gold standard Holmium:YAG laser. The Holmium laser (λ = 2120 nm) was operated with standard parameters of 600 mJ, 350 μs, 6 Hz, and 270-μm-core optical fiber. TFL (λ = 1908 nm) was operated with 35 mJ, 500 μs, 150-500 Hz, and 100-μm-core fiber. Urinary stones (60% calcium oxalate monohydrate / 40% calcium phosphate), of uniform mass and diameter (4-5 mm) were laser ablated with fibers through a flexible video-ureteroscope under saline irrigation with flow rates of 22.7 ml/min and 13.7 ml/min for the TFL and Holmium laser, respectively. The temperature 3 mm from tube's center and 1 mm above mesh sieve was measured by a thermocouple and recorded during experiments. Total laser and operation times were recorded once all stone fragments passed through a 1.5-mm sieve. Holmium laser time measured 167 +/- 41 s (n = 12). TFL times measured 111 +/- 49 s, 39 +/- 11 s, and 23 +/- 4 s, for pulse rates of 150, 300, and 500 Hz (n = 12 each). Mean peak saline irrigation temperatures reached 24 +/- 1 °C for Holmium, and 33 +/- 3 °C, 33 +/- 7 °C, and 39 +/- 6 °C, for TFL at pulse rates of 150, 300, and 500 Hz. To avoid thermal buildup and provide a sufficient safety margin, TFL lithotripsy should be performed with pulse rates below 500 Hz and/or increased saline irrigation rates. The TFL rapidly fragmented kidney stones due in part to its high pulse rate, high power density, high average power, and reduced stone retropulsion, and may provide a clinical alternative to the conventional Holmium laser for lithotripsy.

Integrated and miniaturized endoscopic devices for use during high power infrared fiber laser surgery

NASA Astrophysics Data System (ADS)

Wilson, Christopher Ryan

The Thulium Fiber Laser (TFL) is currently being studied as a potential alternative to the conventional, solid-state Holmium:YAG laser (Ho:YAG) for the treatment of kidney stones. The TFL is an ideal candidate to replace the Ho:YAG for laser lithotripsy due to a higher absorption coefficient in water of the emitted wavelength, an ability to operate at high pulse rates, and a near single mode, Gaussian spatial beam profile. The higher absorption of the TFL wavelength by water translates to a decrease in ablation threshold by a factor of four. High pulse rate operation allows higher ablation rates than the Ho:YAG, thus decreasing operation time necessary to ablate the urinary stone. The Gaussian spatial beam profile allows the TFL to couple higher laser power into smaller optical fibers than those currently being used for Ho:YAG lithotripsy. This decrease in fiber diameter translates into a potential decrease in the size of ureteroscope working channel, higher saline irrigation rates for improved visibility and safety, and may also extend to a decrease in overall ureteroscope diameter. Furthermore, the improved spatial beam profile reduces the risk of damage to the input end of the fiber. Therefore, the trunk fiber, minus the distal fiber tip, may be preserved and re-used, resulting in significant cost savings. This thesis details rapid TFL lithotripsy at high pulse rates up to 500 Hz, both with and without the aid of a stone retrieval basket, in order to demonstrate the TFL's superior ablation rates over the Ho:YAG. Collateral damage testing of the TFL effect on the ureter wall and Nitinol stone baskets were conducted to ensure patient safety for future clinical use. Proximal fiber end damage testing was conducted to demonstrate fiber preservation, critical for permanent fiber integration. Optical fibers were fitted with fabricated hollow steel tips and integrated with stone retrieval baskets for testing. Ball tipped optical fibers were tested to maintain ablation

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

Peroral cholangioscopy with intracorporeal electrohydraulic lithotripsy for choledocholithiasis.

PubMed

Hixson, L J; Fennerty, M B; Jaffee, P E; Pulju, J H; Palley, S L

1992-03-01

Five patients with choledocholithiasis refractory to standard extraction methods after endoscopic sphincterotomy underwent peroral cholangioscopy with the "mother-daughter" endoscopy system. electrohydraulic lithotripsy of nine stones was performed successfully and without complication, other than minor transient bleeding in one patient. The outer sheath of the "daughter scope" sustained a linear burn in one instance. This method of stone fragmentation is a useful adjunct to achieve ductal clearance in difficult cases.

Increased Risk of New-Onset Hypertension After Shock Wave Lithotripsy in Urolithiasis: A Nationwide Cohort Study.

PubMed

Huang, Shi-Wei; Tsai, Chung-You; Wang, Jui; Pu, Yeong-Shiau; Chen, Pei-Chun; Huang, Chao-Yuan; Chien, Kuo-Liong

2017-10-01

Although shock wave lithotripsy is minimally invasive, earlier studies argued that it may increase patients' subsequent risk of hypertension and diabetes mellitus. This study evaluated the association between shock wave lithotripsy and new-onset hypertension or diabetes mellitus. The Taiwanese National Health Insurance Research Database was used to identify 20 219 patients aged 18 to 65 years who underwent the first stone surgical treatment (shock wave lithotripsy or ureterorenoscopic lithotripsy) between January 1999 and December 2011. A Cox proportional model was applied to evaluate associations. Time-varying Cox models were applied to evaluate the association between the number of shock wave lithotripsy sessions and the incidence of hypertension or diabetes mellitus. After a median follow-up of 74.9 and 82.6 months, 2028 and 688 patients developed hypertension in the shock wave lithotripsy and ureterorenoscopic lithotripsy groups, respectively. Patients who underwent shock wave lithotripsy had a higher probability of developing hypertension than patients who underwent ureterorenoscopic lithotripsy, with a hazard ratio of 1.20 (95% confidence interval, 1.10-1.31) after adjusting for covariates. The risk increased as the number of shock wave lithotripsy sessions increased. However, the diabetes mellitus risk was similar in the shock wave lithotripsy and ureterorenoscopic lithotripsy groups. Furthermore, the hazard ratio did not increase as the number of shock wave lithotripsy sessions increased. Shock wave lithotripsy consistently increased the incidence of hypertension on long-term follow-up. Therefore, alternatives to urolithiasis treatment (eg, endoscopic surgery or medical expulsion therapy) could avoid the hypertension risk. Furthermore, avoiding multiple sessions of shock wave lithotripsy could also evade the hypertension risk. © 2017 American Heart Association, Inc.

Proof-of-concept of a laser mounted endoscope for touch-less navigated procedures

PubMed Central

Kral, Florian; Gueler, Oezguer; Perwoeg, Martina; Bardosi, Zoltan; Puschban, Elisabeth J; Riechelmann, Herbert; Freysinger, Wolfgang

2013-01-01

Background and Objectives During navigated procedures a tracked pointing device is used to define target structures in the patient to visualize its position in a registered radiologic data set. When working with endoscopes in minimal invasive procedures, the target region is often difficult to reach and changing instruments is disturbing in a challenging, crucial moment of the procedure. We developed a device for touch less navigation during navigated endoscopic procedures. Materials and Methods A laser beam is delivered to the tip of a tracked endoscope angled to its axis. Thereby the position of the laser spot in the video-endoscopic images changes according to the distance between the tip of the endoscope and the target structure. A mathematical function is defined by a calibration process and is used to calculate the distance between the tip of the endoscope and the target. The tracked tip of the endoscope and the calculated distance is used to visualize the laser spot in the registered radiologic data set. Results In comparison to the tracked instrument, the touch less target definition with the laser spot yielded in an over and above error of 0.12 mm. The overall application error in this experimental setup with a plastic head was 0.61 ± 0.97 mm (95% CI −1.3 to +2.5 mm). Conclusion Integrating a laser in an endoscope and then calculating the distance to a target structure by image processing of the video endoscopic images is accurate. This technology eliminates the need for tracked probes intraoperatively and therefore allows navigation to be integrated seamlessly in clinical routine. However, it is an additional chain link in the sequence of computer-assisted surgery thus influencing the application error. Lasers Surg. Med. 45:377–382, 2013. © 2013 Wiley Periodicals, Inc. PMID:23737122

Therapeutic applications of lasers in urology: an update.

PubMed

Fried, Nathaniel M

2006-01-01

There has been renewed interest in the use of lasers for minimally invasive treatment of urologic diseases in recent years. The introduction of more compact, higher power, less expensive and more user-friendly solid-state lasers, such as the holmium:yttrium-aluminum-garnet (YAG), frequency-doubled neodymium:YAG and diode lasers has made the technology more attractive for clinical use. The availability of small, flexible, biocompatible, inexpensive and disposable silica optical fiber delivery systems for use in flexible endoscopes has also promoted the development of new laser procedures. The holmium:YAG laser is currently the workhorse laser in urology since it can be used for multiple soft- and hard-tissue applications, including laser lithotripsy, benign prostate hyperplasia, bladder tumors and strictures. More recently, higher power potassium-titanyl-phosphate lasers have been introduced and show promise for the treatment of benign prostatic hyperplasia. On the horizon, newer and more effective photosensitizing drugs are being tested for potential use in photodynamic therapy of bladder and prostate cancer. Additionally, new experimental lasers such as the erbium:YAG, Thulium and Thulium fiber lasers, may provide more precise incision of soft tissues, more efficient laser lithotripsy and more rapid prostate ablation. This review provides an update on the most important new clinical and experimental therapeutic applications of lasers in urology over the past 5 years.

Endoscopic laser treatment of subglottic and tracheal stenosis

NASA Astrophysics Data System (ADS)

Correa, Alex J.; Garrett, C. Gaelyn; Reinisch, Lou

1999-06-01

The ideal laser produces discrete wounds in a reproducible manner. The CO2 laser with its 10.6 micron wavelength is highly absorbed by water, its energy concentrated at the point of impact and the longer wavelength creates less scatter in tissue. The development of binocular endoscopic delivery system for use with binocular microlaryngoscopes have aided in using CO2 laser to treat patients with subglottic and tracheal stenosis. Often, patients with these disease processes require multiple endoscopic or open reconstructive procedures and my ultimately become tracheotomy dependent. The canine model of subglottic stenosis that has been develop allows testing of new agents as adjuncts to laser treatment. Mitomycin-C is an antibiotic with antitumor activity used in chemotherapy and also in ophthalmologic surgery due to its known inhibition of fibroblast proliferation. Current studies indicate this drug to have significant potential for improving our current management of this disease process.

Extracorporeal shock wave lithotripsy for obstructing pancreatic duct calculi.

PubMed

Matthews, K; Correa, R J; Gibbons, R P; Weissman, R M; Kozarek, R A

1997-08-01

A review was done to determine the effectiveness of extracorporeal shock wave lithotripsy (ESWL) in the treatment of impacted pancreatic duct calculi. A total of 19 patients, who were potential candidates for radical pancreatic surgery after unsuccessful endoscopic retrograde cholangiopancreatography, sphincterotomy and attempted stone extraction from the pancreatic ducts, underwent ESWL of the calculi. Followup ranged from 6 months to 6 years. Of the 19 patients 14 avoided a major operation and 6 have remained pain-free for the long term. Two patients died of causes not related to ESWL or endoscopic retrograde cholangiopancreatography. Five patients eventually underwent a Whipple or Puestow procedure for relief of symptoms or persistent obstruction. Complications were minimal. ESWL is a valuable adjunct in patients with impacted pancreatic duct calculi unretrievable by primary endoscopic retrograde cholangiopancreatography.

Fiber optic muzzle brake tip for reducing fiber burnback and stone retropulsion during thulium fiber laser lithotripsy

NASA Astrophysics Data System (ADS)

Hutchens, Thomas C.; Gonzalez, David A.; Irby, Pierce B.; Fried, Nathaniel M.

2017-01-01

The experimental thulium fiber laser (TFL) is being explored as an alternative to the current clinical gold standard Holmium:YAG laser for lithotripsy. The near single-mode TFL beam allows coupling of higher power into smaller optical fibers than the multimode Holmium laser beam profile, without proximal fiber tip degradation. A smaller fiber is desirable because it provides more space in the ureteroscope working channel for increased saline irrigation rates and allows maximum ureteroscope deflection. However, distal fiber tip burnback increases as fiber diameter decreases. Previous studies utilizing hollow steel sheaths around recessed distal fiber tips reduced fiber burnback but increased stone retropulsion. A "fiber muzzle brake" was tested for reducing both fiber burnback and stone retropulsion by manipulating vapor bubble expansion. TFL lithotripsy studies were performed at 1908 nm, 35 mJ, 500 μs, and 300 Hz using a 100-μm-core fiber. The optimal stainless steel muzzle brake tip tested consisted of a 1-cm-long, 560-μm-outer-diameter, 360-μm-inner-diameter tube with a 275-μm-diameter through hole located 250 μm from the distal end. The fiber tip was recessed a distance of 500 μm. Stone phantom retropulsion, fiber tip burnback, and calcium oxalate stone ablation studies were performed ex vivo. Small stones with a mass of 40±4 mg and 4-mm-diameter were ablated over a 1.5-mm sieve in 25±4 s (n=10) without visible distal fiber tip burnback. Reduction in stone phantom retropulsion distance by 50% and 85% was observed when using muzzle brake tips versus 100-μm-core bare fibers and hollow steel tip fibers, respectively. The muzzle brake fiber tip simultaneously provided efficient stone ablation, reduced stone retropulsion, and minimal fiber degradation during TFL lithotripsy.

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

Value of focal applied energy quotient in treatment of ureteral lithiasis with shock waves.

PubMed

Arrabal-Polo, Miguel Angel; Arrabal-Martin, Miguel; Palao-Yago, Francisco; Mijan-Ortiz, Jose Luis; Zuluaga-Gomez, Armando

2012-08-01

The treatment of ureteral lithiasis by extracorporeal shock wave lithotripsy (ESWL) is progressively being abandoned owing to advances in endoscopic lithotripsy. The purpose of this paper is to analyze the causes as to why ESWL is less effective-with a measurable parameter: focal applied energy quotient (FAEQ) that allows us to apply an improvement project in ESWL results for ureteral lithiasis. A prospective observational cohort study with 3-year follow-up and enrollment period was done with three groups of cases. In Group A, 83 cases of ureteral lithiasis were treated by endoscopic lithotripsy using Holmiun:YAG laser. In Group B, 81 cases of ureteral lithiasis were treated by ESWL using Doli-S device (EMSE 220F-XXP). In Group C, 65 cases of ureteral lithiasis were treated by ESWL using Doli-S device (EMSE 220F-XXP) (FAEQ >10). Statistical study and calculation of RR, NNT, Chi-square test, Fisher's exact test, and Student's t test were done. Efficiency quotient (EQ) and focal applied energy quotient [FAEQ = (radioscopy seconds/number of shock waves) × ESWL session J] were analyzed. From the results, the success rate of the treatment using Holmium:YAG laser lithotripsy and ESWL is found to be 94 and 48%, respectively, with a statistically significant difference (p < 0.001). Success rate of endoscopic laser lithotripsy for lumbar ureteral stones was 82% versus 57% of ESWL (p = 0.611). In Group B, FAEQ was 8.12. In Group C, success rate was 93.84% with FAEQ of 10.64%. When we compare results from endoscopic lithotripsy with Holmium:YAG laser in Group B with results from ESWL with FAEQ >10, we do not observe absolute benefit choosing one or the other. In conclusion, the application of ESWL with FAEQ >10, that is, improving radiologic focalization of the calculus and increasing the number of Joules/SW, makes possible a treatment as safe and equally efficient as Holmium:YAG laser lithotripsy in ureteral lithiasis less than 13 mm.

Fiber optic suctioning of urinary stone phantoms during laser lithotripsy

NASA Astrophysics Data System (ADS)

Blackmon, Richard L.; Case, Jason R.; Trammell, Susan R.; Irby, Pierce B.; Fried, Nathaniel M.

2013-03-01

Fiber optic attraction of urinary stones during laser lithotripsy has been previously observed, and this phenomenon may potentially be exploited to pull stones inside the urinary tract without mechanical grasping tools, thus saving the urologist valuable time and space in the ureteroscope's single working channel. In this study, Thulium fiber laser (TFL) high-pulse-rate/low-pulse-energy operation and Holmium:YAG low-pulse-rate/high-pulse-energy operation are compared for fiber optic "suctioning" of Plaster-of-Paris stone phantoms. A TFL with wavelength of 1908 nm, pulse energy of 35 mJ, pulse duration of 500 μs, and pulse rate of 10-350 Hz, and Holmium laser with wavelength of 2120 nm, pulse energy of 35-360 mJ, pulse duration of 300 μs, and pulse rate of 20 Hz were tested using 270-μm-core fibers. A peak "pull" speed of 2.5 mm/s was measured for both TFL (35 mJ and 150-250 Hz) and Holmium laser (210 mJ and 20 Hz). Particle image velocimetry and thermal imaging were used to track water flow for all parameters. Fiber optic suctioning of urinary stone phantoms is feasible for both lasers. However, TFL operation at high-pulse-rates/low-pulse-energies provides faster, smoother stone pulling than Holmium operation at low-pulserates/ high-pulse-energies. After further study, this method may be used to manipulate urinary stones in the clinic.

Complications and salvage options after laser lithotripsy for a vesical calculus in a tetraplegic patient: a case report.

PubMed

Vaidyanathan, Subramanian; Singh, Gurpreet; Selmi, Fahed; Hughes, Peter L; Soni, Bakul M; Oo, Tun

2015-01-01

Laser lithotripsy of vesical calculi in tetraplegic subjects with long-term urinary catheters is fraught with complications because of bladder wall oedema, infection, fragile urothelium, bladder spasms, and autonomic dysreflexia. Severe haematuria should be anticipated; failure to institute measures to minimise bleeding and prevent clot retention can be catastrophic. We present an illustrative case. A tetraplegic patient underwent laser lithotripsy of vesical stone under general anaesthesia. During lithotripsy, severe bladder spasms and consequent rise in blood pressure occurred. Bleeding continued post-operatively resulting in clot retention. CT revealed clots within distended but intact bladder. Clots were sucked out and continuous bladder irrigation was commenced. Bleeding persisted; patient developed repeated clot retention. Cystoscopy was performed to remove clots. Patient developed abdominal distension. Bladder rupture was suspected; bed-side ultrasound scan revealed diffuse small bowel dilatation with mild peritoneal effusion; under-filled bladder containing small clot. Patient developed massive abdominal distension and ileus. Two days later, CT with oral positive contrast revealed intra-peritoneal haematoma at the dome of bladder with perforation at the site of haematoma. Free fluid was noted within the peritoneal cavity. This patient was managed by gastric drainage and intravenous fluids. Patient's condition improved gradually with urethral catheter drainage. Follow-up CT revealed resolution of bladder rupture, perivesical haematoma, and intra-peritoneal free fluid. If bleeding occurs, bladder irrigation should be commenced immediately after surgery to prevent clot retention. When bladder rupture is suspected, CT of abdomen should be done instead of ultrasound scan, which may not reveal bladder perforation. It is debatable whether laparotomy and repair of bladder rupture is preferable to nonoperative management in tetraplegics. Anti-muscarinic drugs should

Laser versus stapler: outcomes in endoscopic repair of Zenker diverticulum.

PubMed

Adam, Stewart I; Paskhover, Boris; Sasaki, Clarence T

2012-09-01

To analyze a single surgeon's experience with endoscopic CO(2) laser and stapler repair of Zenker diverticulum (ZD) by comparing dysphagia and regurgitation outcomes. Retrospective chart review of 148 patient charts. Medical records of all patients receiving endoscopic repair of ZD with either CO(2) laser (61 patients) or stapler (67 patients) were reviewed. Additional data included demographics (age and sex), size (cm), preoperative and postoperative symptoms, need for revision, and complications. Symptoms of dysphagia were graded based on a modified Functional Oral Intake Scale 1 to 4 scale (1 = normal intake; 4 = severely limited/G-tube dependent). Regurgitation was also graded on a 1 to 4 scale (1 = no regurgitation; 4 = aspiration events). We noted no difference in patient age or defect size (laser, 3.26 cm; stapler, 3.53 cm; P .135). Significant differences were noted in return trips to the operating room for failed procedures (laser, 0; stapler, 7; P = .009), length of stay (laser, 3.19 days; stapler, 1.29 days; P < .001), time to oral intake (laser, 3.01 days; stapler, 1.22 days; P < .001). Significant improvement occurred in laser and staple patient symptom scales following surgery (P < .001). Laser dysphagia and regurgitation scores showed greater improvement when compared to stapler scores (P < .001). Endoscopic CO(2) laser and staple methods are effective in treating ZD. The laser can have greater efficacy and result in lower recurrence rates. Both methods are analyzed and compared. Copyright © 2012 The American Laryngological, Rhinological, and Otological Society, Inc.

Revision Zenker diverticulum: laser versus stapler outcomes following initial endoscopic failure.

PubMed

Adam, Stewart I; Paskhover, Boris; Sasaki, Clarence T

2013-04-01

We used a retrospective chart review to analyze revision endoscopic carbon dioxide (CO2) laser and staple repairs of recurrent Zenker diverticulum (ZD). The medical records of patients with recurrent ZD after primary endoscopic repair were selected. The chart data included method of repair (CO2 laser or stapler), demographics (age and sex), defect size (in centimeters), preoperative and postoperative symptoms, and complications. Patients' dysphagia was graded on a modified Functional Oral Intake Scale from 1 to 4 (1 being normal intake and 4 being severely limited intake or gastrostomy tube dependence). Regurgitation was also graded on a 1-to-4 scale (1 being no regurgitation and 4 being aspiration). A total of 148 consecutive patients with ZD were treated with endoscopic repair between 2000 and 2010. Twelve of these patients had revisions after failed primary endoscopic management procedures, all done with the stapler. Eight revision surgeries were performed by CO2 laser, and 4 by stapler repair. No difference was noted in patient age or defect size (laser, 3.06-cm defects; stapler, 2.75-cm defects). The length of hospital stay and the time to oral intake for the patients who had a revision stapler procedure were significantly greater (p values of 0.029 and 0.009) than those for the patients in the primary stapler procedure group. Better postoperative regurgitation scores were noted for patients who had a CO2 laser procedure. Secondary endoscopic repair for ZD recurrence is an effective treatment method. Better symptom outcomes were observed with secondary CO2 laser repair than with stapler revision. Patients with revision stapling had longer hospital stays and a longer time to oral intake than did patients with primary staple repairs.

Endoscopic diode laser therapy for chronic radiation proctitis.

PubMed

Polese, Lino; Marini, Lucia; Rizzato, Roberto; Picardi, Edgardo; Merigliano, Stefano

2018-01-01

The purpose of this study is to determine the effectiveness of endoscopic diode laser therapy in patients presenting rectal bleeding due to chronic radiation proctitis (CRP). A retrospective analysis of CRP patients who underwent diode laser therapy in a single institution between 2010 and 2016 was carried out. The patients were treated by non-contact fibers without sedation in an outpatient setting. Fourteen patients (median age 77, range 73-87 years) diagnosed with CRP who had undergone high-dose radiotherapy for prostatic cancer and who presented with rectal bleeding were included. Six required blood transfusions. Antiplatelet (three patients) and anticoagulant (two patients) therapy was not suspended during the treatments. The patients underwent a median of two sessions; overall, a mean of 1684 J of laser energy per session was used. Bleeding was resolved in 10/14 (71%) patients, and other two patients showed improvement (93%). Only one patient, who did not complete the treatment, required blood transfusions after laser therapy; no complications were noted during or after the procedures. Study findings demonstrated that endoscopic non-contact diode laser treatment is safe and effective in CRP patients, even in those receiving antiplatelet and/or anticoagulant therapy.

Endoscopic laser treatment for rectosigmoid villous adenoma: factors effecting the results

NASA Astrophysics Data System (ADS)

Brunetaud, Jean Marc; Maunoury, Vincent; Cochelard, Dominique; Boniface, Brigitte

1994-12-01

This present work reports the long term results after endoscopic laser treatment in 474 patients with benign rectosigmoid villous adenomas revealed by biopsy. Two types of wavelength were used: The 1.06 micrometers infrared light from the Nd:YAG laser and the green light from the argon laser or the Nd:YAG frequency doubled laser. In some patients, both wavelengths were used. Treatment was completed in 415 patients. Total tumor destruction was obtained in 92.8% of them, a carcinoma was detected in 6.5% on biopsy specimens obtained during laser treatment, and benign villous tissue persisted in 0.7%. During the average 30 mo. follow up period of the patients with total tumor destruction, 18% had a tumor recurrence. Treatment was well tolerated with a 1.8% complication rate (one perforation, one hemorrhage, and 7 stenosis requiring dilatation). Because treatment is long and difficult and cancer rate is high, endoscopic laser should be limited in patients with a circumferential villous adenoma to nonsurgical candidates. The risk of complication after surgery (some being fatal) has to be balanced against the risk of undetected carcinoma in the other patients and the indication for endoscopic laser treatment should be discussed case by case.

Comparison of carbon dioxide laser-assisted versus stapler-assisted endoscopic cricopharyngeal myotomy.

PubMed

Pollei, Taylor R; Hinni, Michael L; Hayden, Richard E; Lott, David G; Mors, Matthew B

2013-09-01

We directly compared endoscopic carbon dioxide (CO2) laser and stapler treatment methods for both cricopharyngeal hypertrophy (CPH) and Zenker's diverticulum (ZD). We performed a single-institution retrospective chart review of 153 patients who underwent either CO2 laser-assisted or stapler-assisted endoscopic cricopharyngeal myotomy (CPM). Isolated CPH was more likely to be treated with the CO2 laser than by stapler techniques. The ZD pouch size decreased significantly after surgery in both laser (p = 0.04) and stapler (p = 0.008) groups. The average duration of the procedure for CPM was longer for the laser than for the stapler (p = 0.01). Both techniques were successful when used in revision procedures. The overall complication rates were not statistically significantly different. Laser surgery trended toward a higher rate of major complications (2.4% versus 0%). Symptomatic recurrence was more likely after stapler surgery (p = 0.002). The rates of revision surgery were similar in the two groups (3.3% for laser and 4.3% for stapler). In the treatment of isolated CPH or ZD, stapler-assisted endoscopic surgery results in a shorter operative time, whereas laser-assisted CPM results in a decreased incidence of symptomatic recurrence.

Update on lasers in urology 2014: current assessment on holmium:yttrium-aluminum-garnet (Ho:YAG) laser lithotripter settings and laser fibers.

PubMed

Kronenberg, Peter; Traxer, Olivier

2015-04-01

The purpose of the study was to review the existing literature on holmium:yttrium-aluminum-garnet laser lithotripsy regarding lithotripter settings and laser fibers. An online search of current and past peer-reviewed literature on holmium laser lithotripsy was performed on several databases, including PubMed, SciElo, and Google Scholar. Relevant studies and original articles about lithotripter settings and laser fibers were examined, and the most important information is summarized and presented here. We examine how the choice of lithotripter settings and laser fibers influences the performance of holmium laser lithotripsy. Traditional laser lithotripter settings are analyzed, including pulse energy, pulse frequency, and power levels, as well as newly developed long-pulse modes. The impact of these settings on ablation volume, fragment size, and retropulsion is also examined. Advantages of small- and large-diameter laser fibers are discussed, and controversies are highlighted. Additionally, the influence of the laser fiber is examined, specifically the fiber tip preparation and the lithotripter settings' influence on tip degradation. Many technical factors influence the performance of holmium laser lithotripsy. Knowing and understanding these controllable parameters allows the urologist to perform a laser lithotripsy procedure safely, efficiently, and with few complications.

Laser and acoustic lens for lithotripsy

DOEpatents

Visuri, Steven R.; Makarewicz, Anthony J.; London, Richard A.; Benett, William J.; Krulevitch, Peter; Da Silva, Luiz B.

2002-01-01

An acoustic focusing device whose acoustic waves are generated by laser radiation through an optical fiber. The acoustic energy is capable of efficient destruction of renal and biliary calculi and deliverable to the site of the calculi via an endoscopic procedure. The device includes a transducer tip attached to the distal end of an optical fiber through which laser energy is directed. The transducer tip encapsulates an exogenous absorbing dye. Under proper irradiation conditions (high absorbed energy density, short pulse duration) a stress wave is produced via thermoelastic expansion of the absorber for the destruction of the calculi. The transducer tip can be configured into an acoustic lens such that the transmitted acoustic wave is shaped or focused. Also, compressive stress waves can be reflected off a high density/low density interface to invert the compressive wave into a tensile stress wave, and tensile stresses may be more effective in some instances in disrupting material as most materials are weaker in tension than compression. Estimations indicate that stress amplitudes provided by this device can be magnified more than 100 times, greatly improving the efficiency of optical energy for targeted material destruction.

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.

Indications and Outcomes of Endoscopic CO2 Laser Cricopharyngeal Myotomy

PubMed Central

Bergeron, Jennifer L.; Chhetri, Dinesh K.

2015-01-01

Objectives/Hypothesis To describe indications, management, and outcomes of endoscopic CO2 laser cricopharyngeal myotomy (CPM). Study Design Case series with chart review. Methods All patients treated with endoscopic CO2 laser CPM over a 6-year period were identified. A retrospective chart review was performed for surgical indication, history and physical examinations, and swallow evaluations. Swallowing outcomes were assessed using the Functional Outcome Swallowing Scale (FOSS); findings were compared across groups. Results Eighty-seven patients underwent endoscopic CO2 laser CPM during the study period for cricopharyngeal dysfunction. Indications included Zenker’s diverticulum (ZD) (39), DiGeorge syndrome (two), stroke (five), nerve injury (two), radiation for head and neck cancer (15), idiopathic (16), hyperfunctional tracheoesophageal speech (five) and dysphagia from cricopharyngeus stricture after laryngectomy (three). Mean, median, and mode time to feeding postoperatively were 1.4, 1, and 0 days respectively. Mean, median, and mode hospital stays were 1.8, 1, and 1 day respectively. Overall, FOSS scores improved from 2.6 to 1.6 (P < .001). Improvement was greatest for patients with ZD (2.4 to 1.0) and cricopharyngeal dysfunction from nerve injury (3.3 to 1.8) and least for those with prior radiation (3.9 to 3.2). All patients undergoing CPM for poor tracheoesophageal speech regained speech postoperatively. No patients developed mediastinitis, abscess, or fistula. Conclusions Endoscopic CO2 laser CPM is a safe treatment for cricopharyngeal dysfunction of various causes, though swallowing outcomes may vary depending on the surgical indication. Early feeding postoperatively after CPM is safe and facilitates early hospital discharge. PMID:24114581

Fiber optic muzzle brake tip for reducing fiber burnback and stone retropulsion during thulium fiber laser lithotripsy.

PubMed

Hutchens, Thomas C; Gonzalez, David A; Irby, Pierce B; Fried, Nathaniel M

2017-01-01

The experimental thulium fiber laser (TFL) is being explored as an alternative to the current clinical gold standard Holmium:YAG laser for lithotripsy. The near single-mode TFL beam allows coupling of higher power into smaller optical fibers than the multimode Holmium laser beam profile, without proximal fiber tip degradation. A smaller fiber is desirable because it provides more space in the ureteroscope working channel for increased saline irrigation rates and allows maximum ureteroscope deflection. However, distal fiber tip burnback increases as fiber diameter decreases. Previous studies utilizing hollow steel sheaths around recessed distal fiber tips reduced fiber burnback but increased stone retropulsion. A “fiber muzzle brake” was tested for reducing both fiber burnback and stone retropulsion by manipulating vapor bubble expansion. TFL lithotripsy studies were performed at 1908 nm, 35 mJ, 500 ?? ? s , and 300 Hz using a 100 - ? m -core fiber. The optimal stainless steel muzzle brake tip tested consisted of a 1-cm-long, 560 - ? m -outer-diameter, 360 - ? m -inner-diameter tube with a 275 - ? m -diameter through hole located 250 ?? ? m from the distal end. The fiber tip was recessed a distance of 500 ?? ? m . Stone phantom retropulsion, fiber tip burnback, and calcium oxalate stone ablation studies were performed ex vivo. Small stones with a mass of 40 ± 4 ?? mg and 4-mm-diameter were ablated over a 1.5-mm sieve in 25 ± 4 ?? s

Characterization of calculus migration during Ho:YAG laser lithotripsy by high speed camera using suspended pendulum method

NASA Astrophysics Data System (ADS)

Zhang, Jian James; Rajabhandharaks, Danop; Xuan, Jason Rongwei; Chia, Ray W. J.; Hasenberg, Tom

2014-03-01

Calculus migration is a common problem during ureteroscopic laser lithotripsy procedure to treat urolithiasis. A conventional experimental method to characterize calculus migration utilized a hosting container (e.g. a "V" grove or a test tube). These methods, however, demonstrated large variation and poor detectability, possibly attributing to friction between the calculus and the container on which the calculus was situated. In this study, calculus migration was investigated using a pendulum model suspended under water to eliminate the aforementioned friction. A high speed camera was used to study the movement of the calculus which covered zero order (displacement), 1st order (speed) and 2nd order (acceleration). A commercialized, pulsed Ho:YAG laser at 2.1 um, 365-um core fiber, and calculus phantom (Plaster of Paris, 10×10×10mm cube) were utilized to mimic laser lithotripsy procedure. The phantom was hung on a stainless steel bar and irradiated by the laser at 0.5, 1.0 and 1.5J energy per pulse at 10Hz for 1 second (i.e., 5, 10, and 15W). Movement of the phantom was recorded by a high-speed camera with a frame rate of 10,000 FPS. Maximum displacement was 1.25+/-0.10, 3.01+/-0.52, and 4.37+/-0.58 mm for 0.5, 1, and 1.5J energy per pulse, respectively. Using the same laser power, the conventional method showed <0.5 mm total displacement. When reducing the phantom size to 5×5×5mm (1/8 in volume), the displacement was very inconsistent. The results suggested that using the pendulum model to eliminate the friction improved sensitivity and repeatability of the experiment. Detailed investigation on calculus movement and other causes of experimental variation will be conducted as a future study.

Endoscopic Carbon Dioxide Laser Photocoagulation Of Bleeding Canine Gastric Ulcers

NASA Astrophysics Data System (ADS)

Gal, Dov; Ron, Nimrod; Orgad, Uri; Katzir, Abraham

1987-04-01

This is the first report which describes carbon dioxide laser photocoagulation of upper gastrointestinal bleeding via a flexible endoscope, using an infrared transmitting siver nalide fiber. Various laser parameters were checked to determine the optimal conditions for hemostasis. Both the acute effects of laser irradiation on tissue and the chronic effects on healing process were examined. Preliminary results indicate that carbon dioxide laser beam can successfully photocoagulate moderately bleeding ulcers.

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 laser parameters. All stones could be reliably disintegrated using the three laser systems at the different settings tested. Even though in our experimental set up the rhodamine 6G dye laser showed the best results, theses were not statistically significant to results obtained with the coumarin dye and the Alexandrite laser at high pulse energies. The mean fiber burn-off of the Alexandrite laser at 80 mJ (Do80:195 mm/cm3 stone vol.) was however 5 to 81 fold higher than with all other laser systems, a fact of clinical relevance as far as possible side effects of the quartz material in the bile duct are not yet known.

Holmium:YAG laser lithotripsy: A dominant photothermal ablative mechanism with chemical decomposition of urinary calculi.

PubMed

Chan, K F; Vassar, G J; Pfefer, T J; Teichman, J M; Glickman, R D; Weintraub, S T; Welch, A J

1999-01-01

Evidence is presented that the fragmentation process of long-pulse Holmium:YAG (Ho:YAG) lithotripsy is governed by photothermal decomposition of the calculi rather than photomechanical or photoacoustical mechanisms as is widely thought. The clinical Ho:YAG laser lithotriptor (2.12 microm, 250 micros) operates in the free-running mode, producing pulse durations much longer than the time required for a sound wave to propagate beyond the optical penetration depth of this wavelength in water. Hence, it is unlikely that shock waves are produced during bubble formation. In addition, the vapor bubble induced by this laser is not spherical. Thus the magnitude of the pressure wave produced at cavitation collapse does not contribute significantly to lithotripsy. A fast-flash photography setup was used to capture the dynamics of urinary calculus fragmentation at various delay times following the onset of the Ho:YAG laser pulse. These images were concurrently correlated with pressure measurements obtained with a piezoelectric polyvinylidene-fluoride needle-hydrophone. Stone mass-loss measurements for ablation of urinary calculi (1) in air (dehydrated and hydrated) and in water, and (2) at pre-cooled and at room temperatures were compared. Chemical and composition analyses were performed on the ablation products of several types of Ho:YAG laser irradiated urinary calculi, including calcium oxalate monohydrate (COM), calcium hydrogen phosphate dihydrate (CHPD), magnesium ammonium phosphate hexahydrate (MAPH), cystine, and uric acid calculi. When the optical fiber was placed perpendicularly in contact with the surface of the target, fast-flash photography provided visual evidence that ablation occurred approximately 50 micros after the initiation of the Ho:YAG laser pulse (250-350 micros duration; 375-400 mJ per pulse), long before the collapse of the cavitation bubble. The measured peak acoustical pressure upon cavitation collapse was negligible (< 2 bars), indicating that

Photothermal laser lithotripsy of uric acid calculi: clinical assessment of the effects of cyanide production

NASA Astrophysics Data System (ADS)

Teichman, Joel M. H.; Champion, Paolo C.; Glickman, Randolph D.; Wollin, Timothy A.; Denstedt, John D.

1999-06-01

The mechanism of holmium:YAG lithotripsy is photothermal. Holmium:YAG lithotripsy of uric acid calculi produces cyanide, which is a known, thermal decomposition produce of uric acid. we review our experience with holmium:YAG lithotripsy of uric acid to determine if there is any clinical evidence of cyanide toxicity. A retrospective analysis of all of our cases of holmium:YAG lithotripsy of uric acid calculi was done. Anesthetic and postoperative data were reviewed. A total of 18 patients with uric acid calculi were tread with holmium:YAG lithotripsy by urethroscopy (5), retrograde nephroscopy (2), percutaneous nephrolithotomy (5) or cystolithotripsy (6). Total holmium:YAG irradiation ranged from 1.2 to 331 kJ. No patient had evidence of increased end-tidal carbon dioxide, change sin electrocardiogram or significant decrease in postoperative serum bicarbonate. An 84 year old woman had decreased diastolic pressure of 30 mm Hg while under general anesthesia. No cyanide related neurologic, cardiac or respiratory complications were noted. These data suggest no significant cyanide toxicity from holmium:YAG lithotripsy or uric acid calculi in typical clinical settings. More specific studies in animals are warranted to characterize the risk.

Variable-focus side-firing endoscopic device

NASA Astrophysics Data System (ADS)

Lemberg, Vladimir G.; Black, Michael

1996-05-01

Conventional side-firing fiber technology exhibits performance limitations and utilizes expensive single-use only devices which often require multiple fibers for laser prostatectomy. Another limitation of existing side-firing fiber technology is its inability to focus the beam to create incisions for urologic applications such as laser TURP (transurethral resectional prostatectomy), tumor necrosis, lithotripsy, genital warts, and photodynamic therapy. Newly introduced variable-focus side-firing endoscopic device utilizes either one or two lenses and a mirror, onto a single cylinder of molded glass. The laser beam exits the optical fiber, passes through the lens, strikes the cylindrical mirror, and traverses the cylindrical surface. Depending on the design, the laser beam is reflected at the angles ranging from 30 degrees to 120 degrees out of the cylindrical lens. A second lens can be formed onto the side of the cylindrical surface at the beam's exit point. Another advantage of the innovative side-firing device is its capability to provide versatile matching to multiple laser wavelengths from 360 nm to 2.5 microns, and achieve power densities great enough to perform vaporization, incision and coagulation of tissue. Precise focusing of the laser beam results in reduced tissue necrosis of surrounding the treatment area as well as in decreased laser radiation back-scattering. Surgeons can very the focus by adjusting the distance from the tip to the target area. The variable focus side-firing device provides a focused beam at the range of 1.0 to 1.5 mm, for incision. Outside this range, it produces a defocused beam for coagulation.

In vitro study concerning the efficiency of the frequency-doubled double-pulse Neodymium:YAG laser (FREDDY) for lithotripsy of calculi in the urinary tract.

PubMed

Zörcher, T; Hochberger, J; Schrott, K M; Kühn, R; Schafhauser, W

1999-01-01

In a preclinical study we have tested both in vitro and in vivo, a new type of pulsed solid-state laser system that has not been applied in urology so far and has been developed for optimized intracorporal lithotripsy of biliary, salivary, and urinary calculi. Sixty one calculi from the human urinary tract were split in vitro into fragments with a remaining particle size of laser. In a supplementary animal test, the bladder mucosa of five rabbits was directly exposed to a highly rated laser beam to be able to assess the tissue lesion potential of the system. All the 61 urinary calculi with different composition were successfully split in vitro within a short period of time (2.5 +/- 4.6 minutes). During histopathologic examination of the exposed bladder walls of the rabbits only a small tissue lesion potential with urothelium changes exclusively at the surface was ascertained. The high degree of fragmentation efficiency, the purchase and maintenance costs, which due to its design are substantially lower in comparison to other laser lithotriptors, and the high degree of safety during application make this new laser a real alternative not only to the present laser lithotripsy systems but also to common ballistic lithotriptors. Copyright 1999 Wiley-Liss, Inc.

Endoscopic laser incision of the prostate

NASA Astrophysics Data System (ADS)

Gilbert, Peter T. O.

1998-07-01

To reduce morbidity and costs of transurethral incision of the prostate in cases with bladder neck obstruction and insignificant prostatic hyperplasia, a Nd:YAG laser, wavelength 1064 nm, was used for endoscopic tissue vaporization. Twenty seven patients suffering from severe urinary obstructive symptoms due to a high-riding vesical neck, were operated on under general anesthesia. Under endoscopic control and by means of a 600 micrometer lateral- firing quartz fiber two incisions were performed, starring at the 7 o'clock and 5 o'clock position, respectively, of the bladder neck and following the floor of the prostatic urethra to either side of the verumontanum. Vaporization was achieved with the fiber in permanent tissue contact and the laser working at 60 W power in continuous mode. Total energy averaged 10,000 J. No catheter was inserted and all patients were discharged on the same day after the first micturition. Anti-inflammatory agents were administered for two weeks. No serious complications were encountered postoperatively. Results were evaluated by means of clinical examination, uroflowmetry, sonographic measurement of residual urine and the International Prostate Symptom Score (IPSS) questionnaire. Considering a mean follow up of 15 months, all patients experienced considerable improvement of their obstruction, their urinary peak flow averaging 21 ml/s and their IPSS score 6.7 (preoperatively 12.2 ml/s and 21.8, respectively). As compared to the Collings knife, laser-incision of the prostate carries no risk of bleeding, thus obviating the need of catheterization. It can safely be done in an outpatient setting, probably as well under local as under general anesthesia.

Endoscopic removal of laser-cut covered self-expandable metallic biliary stents: A report of six cases.

PubMed

Tanisaka, Yuki; Ryozawa, Shomei; Kobayashi, Masanori; Harada, Maiko; Kobatake, Tsutomu; Omiya, Kumiko; Iwano, Hirotoshi; Arai, Shin; Nonaka, Kouichi; Mashimo, Yumi

2018-02-01

Covered self-expandable metallic stents (CSEMS) may provide palliative drainage for unresectable distal malignant biliary strictures. Laser-cut CSEMS allows easy positioning due to its characteristic of minimal stent shortening. Endoscopic stent removal is sometimes recommended for recurrent biliary obstruction (RBO). However, there are no previous reports of endoscopic removal of laser-cut CSEMS. The current study presents data from 6 patients who were placed a laser-cut CSEMS for unresectable distal malignant biliary strictures, and later endoscopic stent removal was attempted for RBO at the present institute. The duration of stent placement, the procedural success rate, the procedural duration, and accidental complications were evaluated. The mean duration of stent placement was 156±37.9 days (range, 117-205). The procedural success rate was 100%. The mean procedural duration was 11.8±7.5 min (range, 5-24). No complications were reported. Laser-cut CSEMS were safely removed from all patients. The present case report is the first to demonstrate that Endoscopic stent removal of laser-cut CSEMS was safely performed.

Stone retropulsion during holmium:YAG lithotripsy.

PubMed

Lee, Ho; Ryan, R Tres; Teichman, Joel M H; Kim, Jeehyun; Choi, Bernard; Arakeri, Navanit V; Welch, A J

2003-03-01

We modeled retropulsion during holmium:YAG lithotripsy on the conservation of momentum, whereby the force of ejected fragment debris off of the calculous surface should equal the force of retropulsion displacing the stone. We tested the hypothesis that retropulsion occurs as a result of ejected stone debris. Uniform calculous phantoms were irradiated with holmium:YAG energy in air and in water. Optical fiber diameter and pulse energy were varied. Motion of the phantom was monitored with high speed video imaging. Laser induced crater volume and geometry were characterized by optical coherence tomography. To determine the direction of plume laser burn paper was irradiated at various incident angles. Retropulsion was greater for phantoms irradiated in air versus water. Retropulsion increased as fiber diameter increased and as pulse energy increased (p <0.001). Crater volumes increased as pulse energy increased (p <0.05) and generally increased as fiber diameter increased. Crater geometry was wide and shallow for larger fibers, and narrow and deeper for smaller fibers. The ejected plume propagated in the direction normal to the burn paper surface regardless of the laser incident angle. Retropulsion increases as pulse energy and optical fiber diameter increase. Vector analysis of the ejected plume and crater geometry explains increased retropulsion using larger optical fibers. Holmium:YAG lithotripsy should be performed with small optical fibers to limit retropulsion.

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.

Confocal laser endomicroscopy: in vivo endoscopic tissue analysis.

PubMed

Smith, Christine; Ogilvie, Jeanette; McClelland, Laurie

2008-01-01

In today's fast-paced world of instant messaging, high-speed Internet, and cell phones, patients want results of procedures in the same high-speed fashion. The development of the new technique of confocal laser endomicroscopy and the restructuring of the endoscope may enable quick procedure results to be delivered. First used in Germany and Australia for research and now available for clinical use, confocal laser endomicroscopy has been approved by the Food and Drug Administration for marketing and clinical use in the United States. This article provides the gastroenterology nurse with information about how the confocal laser endomicroscope works, assisting with the procedure, and pre- and postprocedure patient instructions.

Calculus migration characterization during Ho:YAG laser lithotripsy by high-speed camera using suspended pendulum method.

PubMed

Zhang, Jian James; Rajabhandharaks, Danop; Xuan, Jason Rongwei; Chia, Ray W J; Hasenberg, Thomas

2017-07-01

Calculus migration is a common problem during ureteroscopic laser lithotripsy procedure to treat urolithiasis. A conventional experimental method to characterize calculus migration utilized a hosting container (e.g., a "V" grove or a test tube). These methods, however, demonstrated large variation and poor detectability, possibly attributed to the friction between the calculus and the container on which the calculus was situated. In this study, calculus migration was investigated using a pendulum model suspended underwater to eliminate the aforementioned friction. A high-speed camera was used to study the movement of the calculus which covered zero order (displacement), first order (speed), and second order (acceleration). A commercialized, pulsed Ho:YAG laser at 2.1 μm, a 365-μm core diameter fiber, and a calculus phantom (Plaster of Paris, 10 × 10 × 10 mm 3 ) was utilized to mimic laser lithotripsy procedure. The phantom was hung on a stainless steel bar and irradiated by the laser at 0.5, 1.0, and 1.5 J energy per pulse at 10 Hz for 1 s (i.e., 5, 10, and 15 W). Movement of the phantom was recorded by a high-speed camera with a frame rate of 10,000 FPS. The video data files are analyzed by MATLAB program by processing each image frame and obtaining position data of the calculus. With a sample size of 10, the maximum displacement was 1.25 ± 0.10, 3.01 ± 0.52, and 4.37 ± 0.58 mm for 0.5, 1, and 1.5 J energy per pulse, respectively. Using the same laser power, the conventional method showed <0.5 mm total displacement. When reducing the phantom size to 5 × 5 × 5 mm 3 (one eighth in volume), the displacement was very inconsistent. The results suggested that using the pendulum model to eliminate the friction improved sensitivity and repeatability of the experiment. A detailed investigation on calculus movement and other causes of experimental variation will be conducted as a future study.

Flexible ureterorenoscopy and laser lithotripsy in children

PubMed Central

Yeow, When-Chan; Pemberton, Richard; Barker, Andrew

2009-01-01

Background: Flexible ureterorenoscopy (FUR) and laser lithotripsy (LL) are techniques used in the management of upper urinary tract disorders. These techniques, so far established in adults, are now being used in children as well. We report our experience with 26 cases of pediatric upper urinary tract disorders treated using these techniques. Methods: In the period from 1997 to 2006, FUR was performed in 26 children (14 males and 12 females) in the age group of three months to 15 years with a mean age of 8.2 years. Twenty five were stented prior to undergoing FUR and 24 presented with suspected upper tract stones (17 pelvicalyceal and seven midureteric). Two cases showed JJ stent migration post-pyeloplasty. Results: Eight cases involved diagnostic procedures. Six excluded the presence of renal calculi, one had focal medullary sponge kidney, and one had calcified papillae. There were 15 cases of therapeutic FUR. Of these, 12 had LL with only one had incomplete stone fragmentation which subsequently passed spontaneously. Other therapeutic procedures included removal of migrated JJ stents and FUR with the basket removal of a midureteric calculus. Three cases failed ureterorenoscopy due to technical difficulties. The overall success rate was 88.5% for FUR. Conclusion: FUR and LL are valuable minimally invasive techniques for the examination and treatment of pediatric upper urinary tract conditions. Preoperative stenting improves passage of the ureteroscope and with progressive miniaturization of instruments, the lower weight limit will decrease. PMID:20671848

Endoscopic versus surgical drainage treatment of calcific chronic pancreatitis.

PubMed

Jiang, Li; Ning, Deng; Cheng, Qi; Chen, Xiao-Ping

2018-04-21

Endoscopic therapy and surgery are both conventional treatments to remove pancreatic duct stones that developed during the natural course of chronic pancreatitis. However, few studies comparing the effect and safety between surgery drainage and endoscopic drainage (plus Extracorporeal Shock Wave Lithotripsy, ESWL).The aim of this study was to compare the benefits between endoscopic and surgical drainage of the pancreatic duct for patients with calcified chronic pancreatitis. A total of 86 patients were classified into endoscopic/ESWL (n = 40) or surgical (n = 46) treatment groups. The medical records of these patients were retrospectively analyzed. Pain recurrence and hospital stays were similar between the endoscopic/ESWL treatment and surgery group. However, endoscopic/ESWL treatment yielded significantly lower medical expense and less complications compared with the surgical treatment. In selective patients, endoscopic/ESWL treatment could achieve comparable efficacy to the surgical treatment. With lower medical expense and less complications, endoscopic/ESWL treatment would be much preferred to be the initial treatment of choice for patients with calcified chronic pancreatitis. Copyright © 2018 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.

Diode laser assisted minimal invasive sphenoidotomy for endoscopic transphenoidal pituitary surgery: our technique and results.

PubMed

Lee, Jih-Chin; Lai, Wen-Sen; Ju, Da-Tong; Chu, Yueng-Hsiang; Yang, Jinn-Moon

2015-03-01

During endoscopic sinus surgery (ESS), intra-operative bleeding can significantly compromise visualization of the surgical field. The diode laser that provides good hemostatic and vaporization effects and excellent photocoagulation has been successfully applied in endoscopic surgery with several advantages. The current retrospective study demonstrates the feasibility of diode laser-combined endoscopic sinus surgery on sphenoidotomy. The patients who went through endoscopic transphenoidal pituitary surgery were enrolled. During the operation, the quality of the surgical field was assessed and graded by the operating surgeon using the scale proposed by Boezaart. The mean operation time was 37.80 ± 10.90 minutes. The mean score on the quality of surgical field was 1.95. A positive correlation between the lower surgical field quality score and the shorter surgical time was found with statistical significance (P < 0.0001). No infections, hemorrhages, or other complications occurred intra- or post-operatively. The diode laser-assisted sphenoidotomy is a reliable and safe approach of pituitary gland surgery with minimal invasiveness. It is found that application of diode laser significantly improved quality of surgical field and shortened operation time. © 2015 Wiley Periodicals, Inc.

Modelling of a laser-pumped light source for endoscopic surgery

NASA Astrophysics Data System (ADS)

Nadeau, Valerie J.; Elson, Daniel S.; Hanna, George B.; Neil, Mark A. A.

2008-09-01

A white light source, based on illumination of a yellow phosphor with a fibre-coupled blue-violet diode laser, has been designed and built for use in endoscopic surgery. This narrow light probe can be integrated into a standard laparoscope or inserted into the patient separately via a needle. We present a Monte Carlo model of light scattering and phosphorescence within the phosphor/silicone matrix at the probe tip, and measurements of the colour, intensity, and uniformity of the illumination. Images obtained under illumination with this light source are also presented, demonstrating the improvement in illumination quality over existing endoscopic light sources. This new approach to endoscopic lighting has the advantages of compact design, improved ergonomics, and more uniform illumination in comparison with current technologies.

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.

KTP laser assisted endoscopic tissue fibrin glue biocauterization for congenital pyriform sinus fistula in children.

PubMed

Huang, Yun-Chen; Peng, Steve Shinn-Forng; Hsu, Wei-Chung

2016-06-01

This study aims to assess the efficacy of a novel endoscopic management for congenital pyriform sinus fistula (CPSF) using potassium titanyl phosphate (KTP) laser assisted endoscopic tissue fibrin glue biocauterization in children. From 2010 to 2014, a total of 5 children with recurrent or acute suppurative thyroiditis or neck abscess secondary to CPSF were enrolled retrospectively in this study. Mean age at the first time of endoscopic biocauterization was 6.2 ± 0.7 (5-7) years. The barium swallow study detected a fistula in four cases. Endoscopy identified an internal opening at the pyriform sinus in all cases with four on the left side and one on the right side. All patients underwent KTP laser assisted endoscopic tissue fibrin glue biocauterization as treatment for CPSF. Only one case required the second endoscopic procedure due to fluctuation of symptoms. Post-endoscopic follow-up duration of these patients was 24.6 ± 11.6 (7-36) months. Neither complications nor recurrences were noted during follow-up in all patients. For children presenting with repeated acute suppurative thyroiditis or neck infections, clinicians should highly suspect the possibility of CPSF. Endoscopy should be performed not only to confirm the diagnosis but also could be served as an initial treatment modality of biocauterization by KTP laser and tissue fibrin glue, which was demonstrated as a less invasive, safe, and effective method in children. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Utility and safety of the flexible-fiber CO2 laser in endoscopic endonasal transsphenoidal surgery.

PubMed

Jayarao, Mayur; Devaiah, Anand K; Chin, Lawrence S

2011-01-01

This study sought to report on the utility and safety of the flexible-fiber CO2 laser in endoscopic endonasal transsphenoidal surgery. A retrospective chart review identified 16 patients who underwent laser-assisted transsphenoidal surgery. All tumor pathology types were considered. Results were assessed based on hormone status, tumor size, pathology, complications, and resection rates. Sixteen pituitary lesions (pituitary adenomas, 12; Rathke cleft cyst, 2; pituitary cyst and craniopharyngioma, 1 each) with an average size of 22.7 mm were identified by radiographic and pathologic criteria. All patients underwent flexible-fiber CO2 laser-assisted endoscopic endonasal transsphenoidal surgery. Of the adenomas, 8 were nonsecreting and 4 were secreting (3 prolactinomas and 1 ACTH secreting). Gross total resection was achieved in 7 of 16 patients (43.75%) with hormone remission in all patients (100%) after a mean follow-up of 19.3 months. Postoperative complications occurred in 3 patients (18.75%): 2 patients developed transient diabetes insipidus (DI) and 1 developed a CSF leak requiring surgical repair. Five patients (31.25%) underwent postoperative radiation to the residual lesions. We found that CO2-laser-assisted endoscopic endonasal transsphenoidal surgery for sellar tumors is a minimally invasive approach using a tool that is quick and effective at cutting and coagulation. The surgery has a low rate of complication, and no laser-related complications were encountered. The laser fiber allows the surgeon to safely cut and coagulate without the line-of-sight problems encountered with conventional CO2 lasers. Further studies are recommended to further define its role in endoscopic endonasal sellar surgery. Copyright © 2011 Elsevier Inc. All rights reserved.

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.

Endoscopic laser range scanner for minimally invasive, image guided kidney surgery

NASA Astrophysics Data System (ADS)

Friets, Eric; Bieszczad, Jerry; Kynor, David; Norris, James; Davis, Brynmor; Allen, Lindsay; Chambers, Robert; Wolf, Jacob; Glisson, Courtenay; Herrell, S. Duke; Galloway, Robert L.

2013-03-01

Image guided surgery (IGS) has led to significant advances in surgical procedures and outcomes. Endoscopic IGS is hindered, however, by the lack of suitable intraoperative scanning technology for registration with preoperative tomographic image data. This paper describes implementation of an endoscopic laser range scanner (eLRS) system for accurate, intraoperative mapping of the kidney surface, registration of the measured kidney surface with preoperative tomographic images, and interactive image-based surgical guidance for subsurface lesion targeting. The eLRS comprises a standard stereo endoscope coupled to a steerable laser, which scans a laser fan beam across the kidney surface, and a high-speed color camera, which records the laser-illuminated pixel locations on the kidney. Through calibrated triangulation, a dense set of 3-D surface coordinates are determined. At maximum resolution, the eLRS acquires over 300,000 surface points in less than 15 seconds. Lower resolution scans of 27,500 points are acquired in one second. Measurement accuracy of the eLRS, determined through scanning of reference planar and spherical phantoms, is estimated to be 0.38 +/- 0.27 mm at a range of 2 to 6 cm. Registration of the scanned kidney surface with preoperative image data is achieved using a modified iterative closest point algorithm. Surgical guidance is provided through graphical overlay of the boundaries of subsurface lesions, vasculature, ducts, and other renal structures labeled in the CT or MR images, onto the eLRS camera image. Depth to these subsurface targets is also displayed. Proof of clinical feasibility has been established in an explanted perfused porcine kidney experiment.

Endoscopic-assisted disruption of urinary calculi using a holmium:YAG laser in standing horses.

PubMed

Judy, Carter E; Galuppo, Larry D

2002-01-01

To describe a technique for endoscope-assisted disruption and removal of urinary calculi using a holmium:YAG laser in sedated, standing horses. Retrospective study. Six horses with urinary calculi. A holmium:YAG laser was used to disrupt naturally occurring urinary calculi in horses (4 geldings, 1 stallion, 1 mare). Ischial urethrotomy was performed in male horses to provide a portal for the endoscope and laser fiber. Calculus fragments were removed by a combination of lavage, transendoscopic basket snare removal, forceps, and digital manipulation. Ischial urethrotomies healed by second intention. Follow-up was obtained by recheck examination and telephone interview of owners. No major operative or postoperative complications occurred. Two calculi (1 stallion and 1 mare) were fragmented by a combination of laser ablation and manual disruption with a lithotrite. Postoperative dysuria occurred in the mare, but resolved after 1 month. Mean (+/- SD) follow-up was 306 +/- 149 days; no other complications were reported. Calcium carbonate urinary calculi (up to 15 cm in diameter) in horses can be effectively fragmented with a holmium:YAG laser. It is not known if this technique would be completely effective for larger calculi or extremely dense calculi. Calculus disruption by an endoscopically assisted holmium:YAG laser offers a minimally invasive method that can be performed in standing horses and that minimizes patient risk. Copyright 2002 by The American College of Veterinary Surgeons

Endoscopic laser-assisted dacryocistorhinostomy DCR with the placement of a customised silicone and Teflon bicanalicular stent Endoscopic laser-assisted dacryocystorhinostomy (DCR).

PubMed

D'Ecclesia, A; Cocchi, R F; Giordano, F; Mazzilli, E; Longo, C; Laborante, A

We present our experience in endoscopic laser assisted dacryocystorhinostomy (DCR) analyzing the results obtained with a new technique that involves placing bicanalicolar silicone stent more Teflon tube, in combination with paraseptal silastic sheet. In our study 49 of 57 patients (85%) at a mean follow up of at least 12 months have not reported epiphora or more episodes of acute dacryocystitis. 49 out of the 57 patients (85%) in our group reported no additional epiphora or episodes of acute dacryocystitis. Endoscopic DCR is currently the gold standard for sac and post-sac stenosis given the minimal invasiveness of the procedure and the long-term results that appear comparable to those obtained with extrinsic DCR. The principal problem is cicatricial stenosis that can occlude the stoma over time.

[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.

Transurethral lithotripsy with holmium-YAG laser of a large exogenous prostatic calculus.

PubMed

Hasegawa, Masanori; Ohara, Rei; Kanao, Kent; Nakajima, Yosuke

2011-04-01

Prostatic calculi are classified into two types, endogenous and exogenous calculi, based on their origin. Endogenous calculi are commonly observed in elderly men; however, exogenous prostatic calculi are extremely rare. We report here the case of a 51-year-old man who suffered incontinence and pollakiuria with a giant exogenous prostatic calculus almost completely replacing the prostatic tissue. X-rays and computed tomography demonstrated a large calculus of 65 × 58 mm in the small pelvic cavity. The patient underwent a transurethral lithotripsy with a holmium-YAG laser and a total of 85 g of disintegrated stones was retrieved and chemical stone analysis revealed the presence of magnesium ammonium phosphate. The incontinence improved and the voiding volume increased dramatically, and no stone recurrence in the prostatic fossa occurred at the 2 years follow-up. The etiology of this stone formation seemed to be based on some exogenous pathways combined with urinary stasis and chronic urinary infection due to compression fracture of the lumbar vertebra.

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.

Mechanical lithotripsy of pancreatic and biliary stones: complications and available treatment options collected from expert centers.

PubMed

Thomas, Miriam; Howell, Douglas A; Carr-Locke, David; Mel Wilcox, C; Chak, Amitabh; Raijman, Isaac; Watkins, James L; Schmalz, Michael J; Geenen, Joseph E; Catalano, Marc F

2007-09-01

PD and common bile duct (CBD) stones often require mechanical lithotripsy (ML) at ERCP for successful extraction. The frequency and spectrum of complications is not well described in the literature. To describe the frequency and spectrum of complications of ML. A comprehensive retrospective review of cases requiring ML of large or resistant PC and/or CBD stones using a 46-point data questionnaire on type(s) of complication, treatment attempted, and success of treatment. The study involved 7 tertiary referral centers with 712 ML cases (643 biliary and 69 pancreatic). Overall incidence of complications were: 4-4% (31/712); 23/643 biliary, 8/69 pancreatic; 21 single, 10 multiple. Biliary complications: trapped (TR)/broken (BR) basket (N = 11), wire fracture (FX) (N = 8), broken (BR) handle (N = 7), perforation/duct injury (N = 3). Pancreatic complications: TR/BR basket (N = 7), wire FX (N = 4), BR handle (N = 5), pancreatic duct leak (N = 1). Endoscopic intervention successfully treated complications in 29/31 cases (93.5%). Biliary group treatments: sphincterotomy (ES) extension (N = 7), electrohydraulic lithotripsy (EHL) (N = 11), stent (N = 3), per-oral Soehendra lithotripsy (N = 8), surgery (N = 1), extracorporeal lithotripsy (N = 5), and dislodge stones/change basket (N = 4). Pancreatic group treatments: ES extension (N = 3), EHL (N = 2), stent (N = 5), Soehendra lithotriptor (N = 4), dislodge stones/change basket (N = 2), extracorporeal lithotripsy (ECL) (N = 1), surgery (N = 1). Perforated viscus patient died at 30 days. The majority of ML in expert centers involved the bile duct. The complication rate of pancreatic ML is threefold greater than biliary lithotripsy. The most frequent complication of biliary and pancreatic ML is trapped/broken baskets. Extension of ES and EHL are the most frequently utilized treatment options.

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.

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.

A Miniaturized, 1.9F Integrated Optical Fiber and Stone Basket for Use in Thulium Fiber Laser Lithotripsy.

PubMed

Wilson, Christopher R; Hutchens, Thomas C; Hardy, Luke A; Irby, Pierce B; Fried, Nathaniel M

2015-10-01

The thulium fiber laser (TFL) is being explored as an alternative laser lithotripter to the standard holmium:yttrium-aluminum-garnet laser. The more uniform beam profile of the TFL enables higher power transmission through smaller fibers. In this study, a 100-μm core, 140-μm outer-diameter (OD) silica fiber with 5-mm length hollow steel tip was integrated with 1.3F (0.433-mm OD) nitinol wire basket to form a 1.9F (0.633-mm OD) device. TFL energy of 30 mJ, 500 μs pulse duration, and 500 Hz pulse rate was delivered to human uric acid stones, ex vivo. Stone ablation rates measured 1.5 ± 0.2 mg/s, comparable to 1.7 ± 0.3 mg/s using bare fiber tips separately with stone basket. With further development, this device may minimize stone retropulsion, allowing more efficient TFL lithotripsy at higher pulse rates. It may also provide increased flexibility, higher saline irrigation rates through the ureteroscope working channel, reduce fiber degradation compared with separate fiber and basket manipulation, and reduce laser-induced nitinol wire damage.

The holmium laser in urology.

PubMed

Wollin, T A; Denstedt, J D

1998-02-01

To review the physics related to the holmium laser, its laser-tissue interactions, and its application to the treatment of urological diseases. The holmium: YAG laser is a solid-state, pulsed laser that emits light at 2100 nm. It combines the qualities of the carbon dioxide and neodymium:YAG lasers providing both tissue cutting and coagulation in a single device. Since the holmium wavelength can be transmitted down optical fibers, it is especially suited for endoscopic surgery. The authors provide a review of the literature as it relates to the holmium laser and its application to urology. The holmium wavelength is strongly absorbed by water. Tissue ablation occurs superficially, providing for precise incision with a thermal injury zone ranging from 0.5 to 1.0 mm. This level of coagulation is sufficient for adequate hemostasis. The most common urologic applications of the holmium laser that have been reported include incision of urethral and ureteral strictures; ablation of superficial transitional cell carcinoma; bladder neck incision and prostate resection; and lithotripsy of urinary calculi. The holmium: YAG laser is a multi-purpose, multi-specialty surgical laser. It has been shown to be safe and effective for multiple soft tissue applications and stone fragmentation. Its utilization in urology is anticipated to increase with time as a result of these features.

Dependence of calculus retropulsion dynamics on fiber size and radiant exposure during Ho:YAG lithotripsy.

PubMed

Lee, Ho; Ryan, Robert T; Kim, Jeehyun; Choi, Bernard; Arakeri, Navanit V; Teichman, Joel M H; Welch, A J

2004-08-01

During pulsed laser lithotripsy, the calculus is subject to a strong recoil momentum which moves the calculus away from laser delivery and prolongs the operation. This study was designed to quantify the recoil momentum during Ho:YAG laser lithotripsy. The correlation among crater shape, debris trajectory, laser-induced bubble and recoil momentum was investigated. Calculus phantoms made from plaster of Paris were ablated with free running Ho:YAG lasers. The dynamics of recoil action of a calculus phantom was monitored by a high-speed video camera and the laser ablation craters were examined with Optical Coherent Tomography (OCT). Higher radiant exposure resulted in larger ablation volume (mass) which increased the recoil momentum. Smaller fibers produced narrow craters with a steep contoured geometry and decreased recoil momentum compared to larger fibers. In the presence of water, recoil motion of the phantom deviated from that of phantom in air. Under certain conditions, we observed the phantom rocking towards the fiber after the laser pulse. The shape of the crater is one of the major contributing factors to the diminished recoil momentum of smaller fibers. The re-entrance flow of water induced by the bubble collapse is considered to be the cause of the rocking of the phantom.

Histologic effects of different technologies for dissection in endoscopic surgery: Nd:YAG laser, high frequency and water-jet.

PubMed

Schurr, M O; Wehrmann, M; Kunert, W; Melzer, A; Lirici, M M; Trapp, R; Kanehira, E; Buess, G

1994-01-01

Precise cutting combined with reliable coagulation of the margins of the lesion is an important requirement for dissection techniques in endoscopic surgery. These requirements are met by the two most common ancillary energy sources applied for endoscopic dissection today, electrosurgery and "thermal lasers", mostly the Nd:YAG. For the comparison of the histological effects of monopolar and bipolar high frequency with the Nd:YAG laser an experimental in vitro and in vivo study has been performed. In order to evaluate the advantages of non thermal dissection for endoscopic procedures, a water jet cutting system was included in the in vitro study. In parenchymatous tissue the water jet was found to be the least traumatic technique, followed by bipolar high frequency, laser and monopolar high frequency. The water jet was not applicable for intestinal dissection since uncontrolled bloating of the rectal wall with uncontrolled disruption of the tissue layers occurred. A general disadvantage is that secure haemostasis in the line of incision is hard to achieve. In the microscopic comparison of the shape of the incision, the Nd:YAG laser produced the smoothest lesions with well-defined margins. The monopolar technique was more often associated with irregular and sometimes fissured margins. These results were confirmed in the in vivo part of the study (Transanal Endoscopic Microsurgery).

History, instrumentation, and techniques of flexible endoscopic laser surgery in horses.

PubMed

Blikslager, A T; Tate, L P

2000-08-01

There are clearly a number of applications for which flexible endoscopic laser surgery has become the state of the art in equine surgery, and the Nd:YAG laser seems to be the most versatile instrument for this type of surgery. Nevertheless, it is critical to understand the advantages and disadvantages of each laser technique. For example, the Nd:YAG laser used in a noncontact fashion seems to be superior when ablation of tissue is required such as treatment of upper airway masses. Conversely, contact Nd:YAG laser techniques have proven themselves to be superior when more precise cutting is advantageous such as treatment of epiglottic entrapment. Ultimately, it seems that a range of lasers is necessary to ensure selection of the most appropriate technique, adding significantly to the expense of equipment but improving the outcome for a range of equine diseases.

Endoscopic cystoventriculostomy and ventriculo-cysternostomy using a 2.0 micron fiber guided cw laser in children with hydrocephalus

NASA Astrophysics Data System (ADS)

Ludwig, Hans C.; Kruschat, Thomas; Knobloch, Torsten; Rostasy, Kevin M.; Teichmann, Heinrich O.; Buchfelder, Michael

2005-08-01

Preterm infants have a high incidence of post hemorrhagic or post infectious hydrocephalus often associated with ventricular or arachnoic cysts which carry a high risk of entrapment of cerebrospinal fluid (CSF). In these cases fenestration and opening of windows within the separating membranes are neurosurgical options. In occlusive hydrocephalus caused by aquaeductal stenosis 3rd ventriculostomy is the primary choice of the operative procedures. Although Nd:YAG and diode lasers have already been used in neuroendoscopic procedures, neurosurgeons avoid the use of high energy lasers in proximity to vital structures because of potential side effects. We have used a recently developed diode pumped solid state (DPSS) laser emitting light at a wavelength of 2.0 micron (Revolix TM LISA laser products, Katlenburg, Germany), which can be delivered through silica fibres towards endoscopic targets. From July 2002 until May 2005 22 endoscopic procedures in 20 consecutive patients (age 3 months to 12 years old) were performed. Most children suffered from complex post hemorrhagic and post infectious hydrocephalus, in whom ventriculoperitoneal shunt devices failed to restore a CSF equilibrium due to entrapment of CSF pathways by the cysts. We used two different endoscopes, a 6 mm Neuroendoscope (Braun Aesculap, Melsungen, Germany) and a 4 mm miniature Neuroscope (Storz, Tuttlingen, Germany). The endoscopes were connected to a standard camera and TV monitor, the laser energy was introduced through a 365 micron core diameter bare ended silica fibre (PercuFib, LISA laser products, Katlenburg, Germany) through the endoscope's working channel. The continuous wave laser was operated at power levels from 5 to 15 Watt in continuous and chopped mode. The frequency of the laser in chopped mode was varied between 5 and 20 Hz. All patients tolerated the procedure well. No immediate or long term side effects were noted. In 3 patients with cystic compression of the 4th ventricle, insertion of

Local shock-wave lithotripsy of distal ureteral calculi.

PubMed

Voges, G E; Wilbert, D M; Stöckle, M; Hohenfellner, R

1988-01-01

Since the initiation of the clinical trial utilizing a second-generation lithotripor (Lithostar, Siemens, Erlangen, FRG), 96 patients with distal ureteral calculi (i.e. calculi below the pelvic brim) underwent local shock-wave lithotripsy. Routine treatment was conducted under intravenous sedation and light analgesia only. Complete stone disintegration was achieved in 84 patients (87.5%), 11 requiring two sessions and 1 patient, three. In 7 patients ureteroscopy became necessary after unsuccessful local shock-wave treatment. In 2 of these patients a 9-french flexible ureteroscope and the Storz Q-switched neodymium-YAG laser was used for stone disintegration. In 3 cases loop extraction and in 2 cases open surgery had to be performed for definitive stone removal. All pre- and postoperative manipulations (except open surgery) were done on the Lithostar. Local shock-wave lithotripsy is a highly successful, noninvasive, time-saving and easily applicable technique. It has become our primary approach in the treatment of distal ureteral calculi.

Hollow steel tips for reducing distal fiber burn-back during thulium fiber laser lithotripsy.

PubMed

Hutchens, Thomas C; Blackmon, Richard L; Irby, Pierce B; Fried, Nathaniel M

2013-07-01

The use of thulium fiber laser (TFL) as a potential alternative laser lithotripter to the clinical holmium:YAG laser is being studied. The TFL's Gaussian spatial beam profile provides efficient coupling of higher laser power into smaller core fibers without proximal fiber tip degradation. Smaller fiber diameters are more desirable, because they free up space in the single working channel of the ureteroscope for increased saline irrigation rates and allow maximum ureteroscope deflection. However, distal fiber tip degradation and "burn-back" increase as fiber diameter decreases due to both excessive temperatures and mechanical stress experienced during stone ablation. To eliminate fiber tip burn-back, the distal tip of a 150-μm core silica fiber was glued inside 1-cm-long steel tubing with fiber tip recessed 100, 250, 500, 1000, or 2000 μm inside the steel tubing to create the hollow-tip fiber. TFL pulse energy of 34 mJ with 500-μs pulse duration and 150-Hz pulse rate was delivered through the hollow-tip fibers in contact with human calcium oxalate monohydrate urinary stones during ex vivo studies. Significant fiber tip burn-back and degradation was observed for bare 150-μm core-diameter fibers. However, hollow steel tip fibers experienced minimal fiber burn-back without compromising stone ablation rates. A simple, robust, compact, and inexpensive hollow fiber tip design was characterized for minimizing distal fiber burn-back during the TFL lithotripsy. Although an increase in stone retropulsion was observed, potential integration of the hollow fiber tip into a stone basket may provide rapid stone vaporization, while minimizing retropulsion.

Comparison of holmium:YAG and thulium fiber laser lithotripsy: ablation thresholds, ablation rates, and retropulsion effects.

PubMed

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

2011-07-01

The holmium:YAG (Ho:YAG) laser lithotriptor is capable of operating at high pulse energies, but efficient operation is limited to low pulse rates (∼10 Hz) during lithotripsy. On the contrary, the thulium fiber laser (TFL) is limited to low pulse energies, but can operate efficiently at high pulse rates (up to 1000 Hz). This study compares stone ablation threshold, ablation rate, and retropulsion for the two different Ho:YAG and TFL operation modes. The TFL (λ = 1908 nm) was operated with pulse energies of 5 to 35 mJ, 500-μs pulse duration, and pulse rates of 10 to 400 Hz. The Ho:YAG laser (λ = 2120 nm) was operated with pulse energies of 30 to 550 mJ, 350-μs pulse duration, and a pulse rate of 10 Hz. Laser energy was delivered through 200- and 270-μm-core optical fibers in contact mode with human calcium oxalate monohydrate (COM) stones for ablation studies and plaster-of-Paris stone phantoms for retropulsion studies. The COM stone ablation threshold for Ho:YAG and TFL measured 82.6 and 20.8 J∕cm(2), respectively. Stone retropulsion with the Ho:YAG laser linearly increased with pulse energy. Retropulsion with TFL was minimal at pulse rates less than 150 Hz, then rapidly increased at higher pulse rates. For minimal stone retropulsion, Ho:YAG operation at pulse energies less than 175 mJ at 10 Hz and TFL operation at 35 mJ at 100 Hz is recommended, with both lasers producing comparable ablation rates. Further development of a TFL operating with both high pulse energies of 100 to 200 mJ and high pulse rates of 100 to 150 Hz may also provide an alternative to the Ho:YAG laser for higher ablation rates, when retropulsion is not a primary concern.

Clinical assessment of diode laser-assisted endoscopic intrasphenoidal vidian neurectomy in the treatment of refractory rhinitis.

PubMed

Lai, Wen-Sen; Cheng, Sheng-Yao; Lin, Yuan-Yung; Yang, Pei-Lin; Lin, Hung-Che; Cheng, Li-Hsiang; Yang, Jinn-Moon; Lee, Jih-Chin

2017-12-01

For chronic rhinitis that is refractory to medical therapy, surgical intervention such as endoscopic vidian neurectomy (VN) can be used to control the intractable symptoms. Lasers can contribute to minimizing the invasiveness of ENT surgery. The aim of this retrospective study is to compare in patients who underwent diode laser-assisted versus traditional VN in terms of operative time, surgical field, quality of life, and postoperative complications. All patients had refractory rhinitis with a poor treatment response to a 6-month trial of corticosteroid nasal sprays and underwent endoscopic VN between November 2006 and September 2015. They were non-randomly allocated into either a cold instrument group or a diode laser-assisted group. Vidian nerve was excised with a 940-nm continuous wave diode laser through a 600-μm silica optical fiber, utilizing a contact mode with the power set at 5 W. A visual analog scale (VAS) was used to grade the severity of the rhinitis symptoms for quality of life assessment before the surgery and 6 months after. Of the 118 patients enrolled in the study, 75 patients underwent cold instrument VN and 43 patients underwent diode laser-assisted VN. Patients in the laser-assisted group had a significantly lower surgical field score and a lower postoperative bleeding rate than those in the cold instrument group. Changes in the VAS were significant in preoperative and postoperative nasal symptoms in each group. The application of diode lasers for vidian nerve transection showed a better surgical field and a lower incidence of postoperative hemorrhage. Recent advancements in laser application and endoscopic technique has made VN safer and more effective. We recommend this surgical approach as a reliable and effective treatment for patients with refractory rhinitis.

Lasers in the management of calcified urinary tract stents

NASA Astrophysics Data System (ADS)

Nseyo, Unyime O.; Tunuguntla, Hari S. G. R.; Crone, Michael

2003-06-01

Indwelling double J ureteral stents are used for internal urinary diversion for ureteral obstruction and post-surgical drainage of the upper urinary tract. Stent calcification is a serious complication especially in those with forgotten stents. In a retrospective review of 16 patients (10 male and 6 female) we found holmium laser to be highly effective in the management of calcified stents. Encrustations/calcifications were noted on the distal end of the sent in 6 patiens (37.5%), middle and distal portions in 2 patients (12.5%), along the entire length of the stent in 3 patients (18.75%), lower portion of the stent in 4 patients (25%) and at the upper and lower ends of the stent in one patient (6.25%). Cystolitholapaxy, retrograde ureteroscopy (URS) with holmium: YAG (yttrium-aluminum-garnet) laser intracorporeal lithotripsy, percutaneous nephrostolithotomy (PNL) and antegrade URS with holmium: YAG laser intracorporeal lithotripsy were effectively performed without intraoperative complications. Lithotripsy became necessary before stent removal in 11 patients (68.75%). Holmium laser lithotripsy was useful in managing 7 patients (43.75%), and shockwave lithotripsy (SWL) in 6 patients (37.5%). In two patients (12.5%) both holmium and SWL were used before the stent can be removed.

Studies On Endoscopic Local Hyperthermia Using Nd-YAG Laser

NASA Astrophysics Data System (ADS)

Tsunekawa, H.; Kanemaki, N.; Furusawa, A.; Hotta, M.; Kuroiwa, A.; Nishida, M.; Mori, N.; Watanabe, Y.; Morise, K.; Iizuka, A.

1987-03-01

Attempting a new method of laser irradiation for depressed gastric carcinoma, using a newly developed interstitial probe and laser attenuator, we applied local hyperthermia with prolonged low watt contact irradiation. Experimental studies were performed with this probe, using BDF1 mice injected hypodermically with Lewis lung carcinoma. A laser power of 2.0 w at the tip of fiber produced the most desirable temperature curve, about 43 - 60°C at the irradiation site. Clinical applications were carried out on 15 patients with early gastric carcinoma (mainly depressed), 10 preoperative pilot cases and 5 inoperable cases. In follow-up operations and biopsies gastric carcinoma was found to have completely dis-appeared in 2 of the preoperative and 4 of the inoperable cases. In the remaining 8 preoperative cases residual traces of carcinoma were found at the margin of the laser ulcer, but not at the bottom of it. We propose that endoscopic local hyperthermia using interstitial probe and low power irradiation (2.0 W) is the safest and most suitable method of dealing with depressed carcinoma.

Endoscopic placement of Jones lacrimal tubes with the assistance of holmium YAG laser.

PubMed

Boboridis, Kostas G; Downes, Richard N

2005-06-01

The aim of this paper is to highlight the use of the Holmium YAG laser in the endoscopic placement of Lester Jones tubes in patients with a blocked canaliculus or failed lacrimal pump function. Sixteen cases with a non-functional canaliculus were included over a one-year period. Following caruncle excision, a 19 G needle is inserted through the medial canthal tissues into the nasal space. Nasal endoscopy confirms the accurate positioning in relation to the nasal anatomy. With the Holmium YAG laser, a tissue channel is fashioned around the guide needle through the structures of the lateral nasal wall to facilitate an accurate and secure placement of the Jones tube. The endoscopic, laser-assisted placement reduces the operating time to less than 20 minutes, minimizes tissue trauma and does not require the initial surgical steps of an open DCR procedure. There were 14 cases (87.5%) with securely retained tubes and two cases (12.5%) that required tube replacement. The advantage of the procedure is especially great in revision surgery where the ostium is opened through scar tissue. Nasal endoscopy with the assistance of the Holmium YAG laser offers simplicity and precision in the placement of Jones tubes. It minimizes tissue trauma and increases the surgical success rate.

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.

Flexible ureteroscopic lithotripsy for the treatment of upper urinary tract calculi in infants

PubMed Central

Li, Jun; Han, Tiandong; Tian, Ye; Wang, Wenying; Du, Yuan

2016-01-01

We evaluated the clinical value of flexible ureteroscopic lithotripsy for the treatment of upper urinary tract calculi in infants. Fifty-five infants with upper urinary tract calculi were included in this study: 41 males and 14 females. Retrograde intrarenal surgery was performed by an 8 Fr/30 cm flexible ureterorenoscope (POLY®) combined with a holmium laser. CT scanning or radiography of the kidneys, ureters, and bladder region was performed one month after the operation to confirm the clearance of calculi. All the 55 infants with calculi in 74 sides underwent 66 flexible ureteroscopic lithotripsy procedures. The median operation time was 30 min. The median amount of flushing fluid was 500 mL. The stone-free rate after a single session treatment was 94.6%, within which 10 infants underwent simultaneous bilateral flexible ureteroscopy lithotripsy. Catheters were retained in 45 infants for 24–48 h after the operation. Continuous high fever due to reflux was present in two cases. Flushing fluid extravasation was found in one infant. Some patients with minor complications, such as mild hematuria, irritation symptoms, and low fever, recovered without treatment. The duration of hospitalization time after the operation was approximately 1–5 days. Flexible ureteroscopic lithotripsy is a safe, highly efficient, minimally invasive, and reproducible operation for removal of upper urinary tract calculi in infants. This technique is a convenient method for postoperative management of patients that enhances their rapid recovery. It is a promising option for therapy of infants ineffectively treated by extracorporeal shockwave lithotripsy. PMID:27633576

Flexible ureteroscopic lithotripsy for the treatment of upper urinary tract calculi in infants.

PubMed

Li, Jun; Xiao, Jing; Han, Tiandong; Tian, Ye; Wang, Wenying; Du, Yuan

2017-01-01

We evaluated the clinical value of flexible ureteroscopic lithotripsy for the treatment of upper urinary tract calculi in infants. Fifty-five infants with upper urinary tract calculi were included in this study: 41 males and 14 females. Retrograde intrarenal surgery was performed by an 8 Fr/30 cm flexible ureterorenoscope (POLY®) combined with a holmium laser. CT scanning or radiography of the kidneys, ureters, and bladder region was performed one month after the operation to confirm the clearance of calculi. All the 55 infants with calculi in 74 sides underwent 66 flexible ureteroscopic lithotripsy procedures. The median operation time was 30 min. The median amount of flushing fluid was 500 mL. The stone-free rate after a single session treatment was 94.6%, within which 10 infants underwent simultaneous bilateral flexible ureteroscopy lithotripsy. Catheters were retained in 45 infants for 24-48 h after the operation. Continuous high fever due to reflux was present in two cases. Flushing fluid extravasation was found in one infant. Some patients with minor complications, such as mild hematuria, irritation symptoms, and low fever, recovered without treatment. The duration of hospitalization time after the operation was approximately 1-5 days. Flexible ureteroscopic lithotripsy is a safe, highly efficient, minimally invasive, and reproducible operation for removal of upper urinary tract calculi in infants. This technique is a convenient method for postoperative management of patients that enhances their rapid recovery. It is a promising option for therapy of infants ineffectively treated by extracorporeal shockwave lithotripsy.

Endoscopic diode laser welding of mucosal grafts on the larynx: a new technique.

PubMed

Wang, Z; Pankratov, M M; Rebeiz, E E; Perrault, D F; Shapshay, S M

1995-01-01

Epithelial coverage of a laryngotracheal wound is an important factor in preventing stenosis, and endoscopic transplantation of a free mucosal graft without stents or sutures would be a significant therapeutic advance. In vitro and in vivo canine studies were performed to explore the feasibility of transplantation with a low-power diode laser (400 mW) enhanced by indocyanine green dye-doped albumin. The tensile strength of graft adherence in 10 cadaver larynges was strong (35.25 +/- 10.39 g). Survival studies in live canine models with a specially designed endoscopic instrument set showed excellent healing at 6, 14, and 28 days. Healing was documented with photography and by histologic examination. Successful endoscopic transplantation of a free mucosal graft should improve results of treatment for laryngotracheal stenosis and laryngeal reconstructive surgery.

Endoscopic laser-induced steam generator: a new method of treatment for early gastric cancer

NASA Astrophysics Data System (ADS)

Hayashi, Takuya; Arai, Tsunenori; Tajiri, Hisao; Nogami, Yashiroh; Hino, Kunihiko; Kikuchi, Makoto

1996-05-01

The minimum invasive endoscopic treatment for early gastric cancer has been popular in Japan. The endoscopic mucosal resection and laser coagulation by Nd:YAG laser irradiation has been the popular treatment method in this field. However, the submucosal cancer has not been successfully treated by these methods. To treat the submucosal cancer endoscopically, we developed a new coagulation therapy using hot steam generated by Nd:YAG laser. The steam of which temperature was over 10 deg. in Celsius was generated by the laser power of 30 W with 5 ml/min. of saline. The steam was emitted to canine gastric wall under laparotomy or endoscopy for 50 s respectively. Follow up endoscopy was performed on 3, 7, 14, 28 days after the treatment. Histological examination was studied on 7, 28 days, and just after the emission. In the acute observation, the submucosal layer was totally coagulated. On the 7th day, ulceration with white coat was seen. The mucosal defect, submucosal coagulation, and marked edema without muscle degeneration were found by the histological study. On the 14th day, the ulcer advanced in the scar stage. On the 28th day, it completely healed into white scar with mucosal regeneration and mucosal muscle thickening. We could obtain reproducible coagulation up to deep submucosal layer with large area in a short operation time. Moreover there were no degeneration of proper muscle. This treatment effectiveness could be easily controlled by the steam temperature and emission duration. We think that this method can be applied to early gastric cancer including the submucosal cancer, in particular poor risk case for operation. Further study should be done to apply this method to clinical therapy.

Endoscopic cystoventriculostomy and ventriculocysternostomy using a recently developed 2.0-micron fiber-guided high-power diode-pumped solid state laser in children with hydrocephalus

NASA Astrophysics Data System (ADS)

Ludwig, Hans C.; Kruschat, Thomas; Knobloch, Torsten; Rostasy, Kevin; Buchfelder, Michael

2005-04-01

Preterm infants have a high incidence of post hemorrhagic or post infectious hydrocephalus often associated with ventricular or arachnoic cysts which carry a high risk of entrapment of cerebrospinal fluid (CSF). In these cases fenestration and opening of windows within the separating membranes are neurosurgical options. Although Nd:YAG- and diode-lasers have already been used in neuroendoscopic procedures, neurosurgeons avoid the use of high energy lasers in proximity to vital structures because of potential side effects. We have used a recently developed diode pumped solid state (DPSS) laser emitting light at a wavelength of 2.0 μm (Revolix TM LISA laser products, Katlenburg, Germany), which can be delivered through silica fibres towards endoscopic targets. From July 2002 until June 2004 fourteen endoscopic procedures in 12 consecutive patients (age 3 months to 12 years old) were performed. Most children suffered from complex post hemorrhagic and post infectious hydrocephalus, in whom ventriculoperitoneal shunt devices failed to restore a CSF equilibrium due to entrapment of CSF pathways by the cysts. We used two different endoscopes, a 6 mm Neuroendoscope (Braun Aesculap, Melsungen, Germany; a 4 mm miniature Neuroscope (Storz, Tuttlingen, Germany). The endoscopes were connected to a standard camera and TV monitor, the laser energy was introduced through a 365 μm core diameter bare ended silica fibre (PercuFib, LISA laser products, Katlenburg, Germany) through the endoscope"s working channel. The continuous wave laser was operated at power levels from 5 to 15 Watt in continuous and chopped mode. The frequency of the laser in chopped mode was varied between 5 and 20 Hz. All patients tolerated the procedure well. No immediate or long term side effects were noted. In 3 patients with cystic compression of the 4th ventricle, insertion of a shunt device could be avoided. The authors conclude that the use of the new RevolixTM laser enables safe and effective procedures

[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

An integrated fiber and stone basket device for use in Thulium fiber laser lithotripsy

NASA Astrophysics Data System (ADS)

Wilson, Christopher R.; Hutchens, Thomas C.; Hardy, Luke A.; Irby, Pierce B.; Fried, Nathaniel M.

2014-03-01

The Thulium fiber laser (TFL) is being explored as an alternative laser lithotripter to the Holmium:YAG laser. The TFL's superior near-single mode beam profile enables higher power transmission through smaller fibers with reduced proximal fiber tip damage. Recent studies have also reported that attaching hollow steel tubing to the distal fiber tip decreases fiber degradation and burn-back without compromising stone ablation rates. However, significant stone retropulsion was observed, which increased with pulse rate. In this study, the hollow steel tip fiber design was integrated with a stone basket to minimize stone retropulsion during ablation. A device was constructed consisting of a 100-μm-core, 140-μm-OD silica fiber outfitted with 5-mm-long stainless steel tubing at the distal tip, and integrated with a 1.3-Fr (0.433-mm-OD) disposable nitinol wire basket, to form an overall 1.9-Fr (0.633-mm- OD) integrated device. This compact design may provide several potential advantages including increased flexibility, higher saline irrigation rates through the ureteroscope working channel, and reduced fiber tip degradation compared to separate fiber and stone basket manipulation. TFL pulse energy of 31.5 mJ with 500 μs pulse duration and pulse rate of 500 Hz was delivered through the integrated fiber/basket device in contact with human uric acid stones, ex vivo. TFL stone ablation rates measured 1.5 +/- 0.2 mg/s, comparable to 1.7 +/- 0.3 mg/s (P > 0.05) using standard bare fiber tips separately with a stone basket. With further development, this device may be useful for minimizing stone retropulsion, thus enabling more efficient TFL lithotripsy at higher pulse rates.

Endoscopic management of bile duct stones: residual bile duct stones after surgery, cholangitis, and "difficult stones".

PubMed

Karsenti, D

2013-06-01

Endoscopic treatment has become, according to the latest recommendations, the standard treatment for common bile duct stones (CBDS), although in certain situations, surgical clearance of the common duct at the time of laparoscopic cholecystectomy is still considered a possible alternative. The purpose of this article is not to compare endoscopic with surgical treatment of CBDS, but to describe the various techniques of endoscopic treatment, detailing their preferential indications and the various treatment options that must sometimes be considered when faced with "difficult calculi" of the CBD. The different techniques of lithotripsy and the role of biliary drainage with plastic or metallic stents will be detailed as well as papillary balloon dilatation and particularly the technique of sphincterotomy with macrodilatation of the sphincter of Oddi (SMSO), a recently described approach that has changed the strategy for endoscopic management of CBDS. Finally, the overall strategy for endoscopic management of CBDS, with description of different techniques, will be exposed. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Evaluation of the shock-wave pattern for endoscopic electrohydraulic lithotripsy.

PubMed

Vorreuther, R; Engelmann, Y

1995-01-01

We evaluated the electrical events and the resulting shock waves of the spark discharge for electrohydraulic lithotripsy at the tip of a 3.3F probe. Spark generation was achieved by variable combinations of voltage and capacity. The effective electrical output was determined by means of a high-voltage probe, a current coil, and a digital oscilloscope. Peak pressures, rise times, and pulse width of the pressure profiles were recorded using a polyvinylidene difluoride needle hydrophone in 0.9% NaCl solution at a distance of 10 mm. The peak pressure and the slope of the shock front depend solely on the voltage, while the pulse width was correlated with the capacity. Pulses of less than 1-microsecond duration can be obtained when low capacity is applied and the inductivity of the cables and plugs is kept at a low level. Using chalk as a stone model it was proven that short pulses of high peak pressure provided by a low capacity and a high voltage have a greater impact on fragmentation than the corresponding broader shock waves of lower peak pressure carrying the same energy.

An endoscopic laser Doppler flowmetry of a gastroduodenal mucosa at bleeding ulcer

NASA Astrophysics Data System (ADS)

Shapkin, U. G.; Kapralov, C. V.; Gogolev, A. A.; Lychagov, V. V.; Tuchin, V. V.

2006-08-01

One of the important problems of a bleeding gastroduodenal ulcer surgery is a prognosis of the recurrent hemorrhage and appraisal of endoscopic hemostasis quality. Endoscopic Laser Doppler Flowmetry of a mucous coat of stomach and a duodenum was made on 34 patients for the purpose of investigation of features of microcirculation. Analogous researches are made on 30 patients with a peptic ulcer and on 28 practically healthy people. Analysis of LDF-grams has shown certain differences in regional microcirculations in stomach and duodenal at normal and at a pathology. Increase of regional perfusion in periulcerose zone with its pathology disbalance can serve as a criterion for activities of an alteration processes in gastroduodenal ulcer defining the risk of possible hemorrhage.

A multicenter, randomized, controlled trial of transureteral and shock wave lithotripsy--which is the best minimally invasive modality to treat distal ureteral calculi in children?

PubMed

Basiri, Abbas; Zare, Samad; Tabibi, Ali; Sharifiaghdas, Farzaneh; Aminsharifi, Alireza; Mousavi-Bahar, Seyed Habibollah; Ahmadnia, Hassan

2010-09-01

Since there is insufficient evidence to determine the best treatment modality in children with distal ureteral calculi, we designed a multicenter, randomized, controlled trial to evaluate the efficacy and complications of transureteral and shock wave lithotripsy in these patients. A total of 100 children with distal ureteral calculi were included in the study. Of the patients 50 were randomized consecutively to undergo shock wave lithotripsy using a Compact Delta II lithotriptor (Dornier MedTech, Kennesaw, Georgia), and 50 were randomized to undergo transureteral lithotripsy with holmium laser and pneumatic lithotriptor between February 2007 and October 2009. Stone-free, complication and efficiency quotient rates were assessed in each group. Mean +/- SD patient age was 6.5 +/- 3.7 years (range 1 to 13). Mean stone surface was 35 mm(2) in the transureteral group and 37 mm(2) in the shock wave lithotripsy group. Stone-free rates at 2 weeks after transureteral lithotripsy and single session shock wave lithotripsy differed significantly, at 78% and 56%, respectively (p = 0.004). With 2 sessions of shock wave lithotripsy the stone-free rate increased to 72%. Efficiency quotient was significantly higher for transureteral vs shock wave lithotripsy (81% vs 62%, p = 0.001). Minor complications were comparable and negligible between the groups. Two patients (4%) who underwent transureteral lithotripsy sustained a ureteral perforation. In the short term it seems that transureteral and shock wave lithotripsy are acceptable modalities for the treatment of distal ureteral calculi in children. However, transureteral lithotripsy has a higher efficacy rate when performed meticulously by experienced hands using appropriate instruments. 2010 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Photoactive dye enhanced tissue ablation for endoscopic laser prostatectomy

NASA Astrophysics Data System (ADS)

Ahn, Minwoo; Nguyen, Trung Hau; Nguyen, Van Phuc; Oh, Junghwan; Kang, Hyun Wook

2015-02-01

Laser light has been widely used as a surgical tool to treat benign prostate hyperplasia with high laser power. The purpose of this study was to validate the feasibility of photoactive dye injection to enhance light absorption and eventually to facilitate tissue ablation with low laser power. The experiment was implemented on chicken breast due to minimal optical absorption Amaranth (AR), black dye (BD), hemoglobin powder (HP), and endoscopic marker (EM), were selected and tested in vitro with a customized 532-nm laser system with radiant exposure ranging from 0.9 to 3.9 J/cm2. Light absorbance and ablation threshold were measured with UV-VIS spectrometer and Probit analysis, respectively, and compared to feature the function of the injected dyes. Ablation performance with dye-injection was evaluated in light of radiant exposure, dye concentration, and number of injection. Higher light absorption by injected dyes led to lower ablation threshold as well as more efficient tissue removal in the order of AR, BD, HP, and EM. Regardless of the injected dyes, ablation efficiency principally increased with input parameter. Among the dyes, AR created the highest ablation rate of 44.2+/-0.2 μm/pulse due to higher absorbance and lower ablation threshold. Preliminary tests on canine prostate with a hydraulic injection system demonstrated that 80 W with dye injection yielded comparable ablation efficiency to 120 W with no injection, indicating 33 % reduced laser power with almost equivalent performance. In-depth comprehension on photoactive dye-enhanced tissue ablation can help accomplish efficient and safe laser treatment for BPH with low power application.

In-Office Endoscopic Laryngeal Laser Procedures: A Patient Safety Initiative.

PubMed

Anderson, Jennifer; Bensoussan, Yael; Townsley, Richard; Kell, Erika

2018-05-01

Objective To review complications of in-office endoscopic laryngeal laser procedures after implementation of standardized safety protocol. Methods A retrospective review was conducted of the first 2 years of in-office laser procedures at St Michaels Hospital after the introduction of a standardized safety protocol. The protocol included patient screening, procedure checklist with standardized reporting of processes, medications, and complications. Primary outcomes measured were complication rates of in-office laryngeal laser procedures. Secondary outcomes included hemodynamic changes, local anesthetic dose, laser settings, total laser/procedure time, and incidence of sedation. Results A total of 145 in-office KTP procedures performed on 65 patients were reviewed. In 98% of cases, the safety protocol was fully implemented. The overall complication rate was 4.8%. No major complications were encountered. Minor complications included vasovagal episodes and patient intolerance. The rate of patient intolerance resulting early termination of anticipated procedure was 13.1%. Total local anesthetic dose averaged 172.9 mg lidocaine per procedure. The mean amount of laser energy dispersed was 261.2 J, with mean total procedure time of 48.3 minutes. Sixteen percent of patients had preprocedure sedation. Vital signs were found to vary modestly. Systolic blood pressure was lower postprocedure in 13.8% and symptomatic in 4.1%. Discussion The review of our standardized safety protocol has revealed that in-office laser treatment for laryngeal pathology has extremely low complication rates with safe patient outcomes. Implications for Practice The trend of shifting procedures out of the operating room into the office/clinic setting requires new processes designed to promote patient safety.

Endoscopic treatment by snare electrocoagulation prior to Nd:YAG laser photocoagulation in 85 voluminous colorectal villous adenomas.

PubMed

Aubert, A; Meduri, B; Fritsch, J; Aime, F; Baglin, A; Barbagelata, M

1991-05-01

The association of endoscopic resection with Nd:YAG laser photocoagulation was used to treat benign colorectal villous adenomas. Eight-five patients were included: 49 with surgical contraindications, 35 for whom surgical resection appeared to be too hazardous, and 1 who refused surgery. Forty-five tumors had an axial extension between 1 and 3 cm, and 40 tumors had an axial extension of at least 4 cm. Diathermic snare resection was performed to remove large tumoral fragments prior to laser photocoagulation of the residual flat lesions. Treatments were repeated every 15 days until total tumor destruction was achieved. A carcinoma was detected in biopsy specimens obtained during endoscopic treatment of five patients. Two patients were lost to follow-up. Treatment results could be analyzed in 78 patients. Successful treatment was achieved in 67 patients. Tumor destruction was complete in 77 percent of patients who had lesions of at least 4 cm diameter and in 93 percent of patients with smaller lesions. The axial extension of the tumor was the main factor affecting the results of treatment. No major complications occurred. During the average 103-week follow-up period, 21 percent of the patients with total tumor destruction had a recurrence. The risk of recurrence was correlated with the number of initial treatment sessions and previous surgery treatment. It would appear that the treatment with endoscopic resection prior to Nd:YAG laser photocoagulation is a safe and effective method in the destruction of colorectal villous adenomas.

Laser applications in surgery

PubMed Central

Azadgoli, Beina

2016-01-01

In modern medicine, lasers are increasingly utilized for treatment of a variety of pathologies as interest in less invasive treatment modalities intensifies. The physics behind lasers allows the same basic principles to be applied to a multitude of tissue types using slight modifications of the system. Multiple laser systems have been studied within each field of medicine. The term “laser” was combined with “surgery,” “ablation,” “lithotripsy,” “cancer treatment,” “tumor ablation,” “dermatology,” “skin rejuvenation,” “lipolysis,” “cardiology,” “atrial fibrillation (AF),” and “epilepsy” during separate searches in the PubMed database. Original articles that studied the application of laser energy for these conditions were reviewed and included. A review of laser therapy is presented. Laser energy can be safely and effectively used for lithotripsy, for the treatment of various types of cancer, for a multitude of cosmetic and reconstructive procedures, and for the ablation of abnormal conductive pathways. For each of these conditions, management with lasers is comparable to, and potentially superior to, management with more traditional methods. PMID:28090508

Evaluation of six holmium:YAG optical fibers for ureteroscopy: What's new in 2009?

NASA Astrophysics Data System (ADS)

Knudsen, Bodo E.; Teichman, Joel M. H.

2010-02-01

The holmium:yttrium aluminum garnet (YAG) laser is the gold standard laser for intracorporeal lithotripsy.1 Optical fibers are utilized to transmit laser energy to the surface of a stone for fragmentation via a predominant photothermal mechanism.2 Previous work has demonstrated that performance characteristics of holmium:YAG optical fibers used for laser lithotripsy varies. Performance may difference not only between fibers made by different manufacturers but also between individual fibers produced by the same manufacturer.3,4 Fiber failure with bending, such as during lower pole ureterorenoscopy, can lead to catastrophic endoscope damage resulting in costly repair. Manufacturers continue to develop new holmium:YAG optical fibers. In this study we evaluate a series of newly commercially available fibers using a previously designed testing protocol. This study was designed to determine the performance and threshold for failure of six newly available holmium:YAG laser fibers from Cook Medical and Fibertech Gmbh. We hypothesize that fiber performance will continue to vary amongst different holmium:YAG optical fibers.

Lithotripsy.

PubMed

Leighton, T G; Cleveland, R O

2010-01-01

Shock wave lithotripsy (SWL) is the process of fragmentation of renal or ureteric stones by the use of repetitive shock waves generated outside the body and focused onto the stone. Following its introduction in 1980, SWL revolutionized the treatment of kidney stones by offering patients a non-invasive procedure. It is now seen as a mature technology and its use is perceived to be routine. It is noteworthy that, at the time of its introduction, there was a great effort to discover the mechanism(s) by which it works, and the type of sound field that is optimal. Although nearly three decades of subsequent research have increased the knowledge base significantly, the mechanisms are still controversial. Furthermore there is a growing body of evidence that SWL results in injury to the kidney which may have long-term side effects, such as new onset hypertension, although again there is much controversy within the field. Currently, use of lithotripsy is waning, particularly with the advent of minimally invasive ureteroscopic approaches. The goal here is to review the state of the art in SWL and to present the barriers and challenges that need to be addressed for SWL to deliver on its initial promise of a safe, effective, non-invasive treatment for kidney stones.

[Endonasal versus trans-canalicular endoscopic dacriocystorhinostomy using diode laser. Surgical techniques and outcomes].

PubMed

Piédrola Maroto, David; Franco Sánchez, Javier; Reyes Eldblom, Robin; Monje Vega, Elena; Conde Jiménez, Manuel; Ortiz Rueda, Manuel

2008-01-01

To evaluate the benefits and disadvantages of the endoscopic endonasal versus transcanalicular approaches using diode laser, and to compare their clinical outcomes. A total of 127 patients were operated on, 80 of them with the endonasal approach (Group I) and 47 with the transcanalicular technique (Group II). Epiphora improved completely in 67 patients in Group I (83.7 %) while the other 13 (16.2 %) continued to present the same symptoms. In Group II, a successful result was achieved in 39 patients (82.9 %) and 8 (17 %) of them had to be re-operated because of the persistence of epiphora. The surgical outcomes are similar with both laser techniques. The main advantages of using diode laser are that it does not require general anaesthesia, the lower intra- and peri-operative morbidity, the lack of nasal packing and the greater ease of performing additional interventions if it fails. The only real disadvantage of laser procedures is the high cost.

Endoscopic Removal of a Nitinol Mesh Stent from the Ureteropelvic Junction after 15 Years

PubMed Central

Smrkolj, Tomaž; Šalinović, Domagoj

2015-01-01

We report a rare case of a patient with a large stone encrusted on a nitinol mesh stent in the ureteropelvic junction. The stent was inserted in the year 2000 after failure of two pyeloplasty procedures performed due to symptomatic ureteropelvic junction stenosis. By combining minimally invasive urinary stone therapies—extracorporeal shock wave lithotripsy, semirigid ureterorenoscopy with laser lithotripsy, and percutaneous nephrolithotomy—it was possible to completely remove the encrusted stone and nitinol mesh stent that was implanted for 15 years, rendering the patient symptom and obstruction free. PMID:26697258

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.

Monitoring blood-flow in the mouse cochlea using an endoscopic laser speckle contrast imaging system

PubMed Central

Yu, Sunkon; Jung, Byungjo; Choi, Jin Sil

2018-01-01

Laser speckle contrast imaging (LSCI) enables continuous high-resolution assessment of microcirculation in real-time. We applied an endoscope to LSCI to measure cochlear blood-flow in an ischemia–reperfusion mouse model. We also explored whether using xenon light in combination with LSCI facilitates visualization of anatomical position. Based on a previous preliminary study, the appropriate wavelength for penetrating the thin bony cochlea was 830 nm. A 2.7-mm-diameter endoscope was used, as appropriate for the size of the mouse cochlea. Our endoscopic LSCI system was used to illuminate the right cochlea after dissection of the mouse. We observed changes in the speckle signals when we applied the endoscopic LSCI system to the ischemia-reperfusion mouse model. The anatomical structure of the mouse cochlea and surrounding structures were clearly visible using the xenon light. The speckle signal of the cochlea was scattered, with an intensity that varied between that of the stapes (with the lowest signal), the negative control, and the stapedial artery (with the highest signal), the positive control. In the cochlear ischemia–reperfusion mouse model, the speckle signal of the cochlea decreased during the ischemic phase, and increased during the reperfusion phase, clearly reflecting cochlear blood-flow. The endoscopic LSCI system generates high-resolution images in real-time, allowing visualization of blood-flow and its changes in the mouse cochlea. Anatomical structures were clearly matched using LSCI along with visible light. PMID:29489849

Monitoring blood-flow in the mouse cochlea using an endoscopic laser speckle contrast imaging system.

PubMed

Kong, Tae Hoon; Yu, Sunkon; Jung, Byungjo; Choi, Jin Sil; Seo, Young Joon

2018-01-01

Laser speckle contrast imaging (LSCI) enables continuous high-resolution assessment of microcirculation in real-time. We applied an endoscope to LSCI to measure cochlear blood-flow in an ischemia-reperfusion mouse model. We also explored whether using xenon light in combination with LSCI facilitates visualization of anatomical position. Based on a previous preliminary study, the appropriate wavelength for penetrating the thin bony cochlea was 830 nm. A 2.7-mm-diameter endoscope was used, as appropriate for the size of the mouse cochlea. Our endoscopic LSCI system was used to illuminate the right cochlea after dissection of the mouse. We observed changes in the speckle signals when we applied the endoscopic LSCI system to the ischemia-reperfusion mouse model. The anatomical structure of the mouse cochlea and surrounding structures were clearly visible using the xenon light. The speckle signal of the cochlea was scattered, with an intensity that varied between that of the stapes (with the lowest signal), the negative control, and the stapedial artery (with the highest signal), the positive control. In the cochlear ischemia-reperfusion mouse model, the speckle signal of the cochlea decreased during the ischemic phase, and increased during the reperfusion phase, clearly reflecting cochlear blood-flow. The endoscopic LSCI system generates high-resolution images in real-time, allowing visualization of blood-flow and its changes in the mouse cochlea. Anatomical structures were clearly matched using LSCI along with visible light.

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

Fragmentation of salivary stones with a 980nm diode laser.

PubMed

Luers, Jan Christoffer; Petry-Schmelzer, Jan Niklas; Hein, Wolfgang G; Gostian, Antoniu-Oreste; Hüttenbrink, Karl-Bernd; Beutner, Dirk

2014-02-01

Intraductal laser lithotripsy is a preferred method to fragment large, immobile intraglandular salivary stones. A number of different laser systems has been investigated for this purpose. It was our aim to study the effectiveness of a 980nm diode laser when fragmenting salivary stones in an experimental set up. In an experimental set up we used a 980nm diode laser for the lithotripsy of 9 salivary stones. The temperature circle around the laser fibre tip was measured and stone remnants were chemically analysed for their composition. The salivary stones had a mean diameter of 6.7mm×5.6mm×3.0mm. Laser fragmentation with the diode laser was successful at all stones. The temperature next to the salivary stone increased to around 30°C during the active lithotripsy with continuous rinsing (fluid temperature 21°C). At a distance of 2mm the temperature around the laser fibre's tip is reduced by already about 50%. The salivary stones mainly consisted of carbonate apatite, followed by β-calcium phosphate and other calcium phosphates. The fragmentation of salivary stones with a 980nm diode laser is possible in principle. Under a continuous irrigation with a positioning of the laser fibre's tip at the centre of the stone, no relevant temperature increase in the vicinity of the stone occurs. However, before the laser is used in humans, in vivo experiments on animal material seem to be advisable. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Direct peroral cholangioscopy using an ultrathin endoscope: making technique easier.

PubMed

Sola-Vera, Javier; Uceda, Francisco; Cuesta, Rubén; Vázquez, Narcís

2014-01-01

Cholangioscopy is a useful tool for the study and treatment of biliary pathology. Ultrathin upper endoscopes allow direct peroral cholangioscopy (DPC) but have some drawbacks. The aim of the study was to evaluate the success rate of DPC with an ultrathin endoscope using a balloon catheter to reach the biliary confluence. Prospective observational study. An ultrathin endoscope (Olympus XP180N, outer diameter 5.5 mm, working channel 2 mm) was used. To access the biliary tree, free-hand technique was used. To reach the biliary confluence an intraductal balloon catheter (Olympus B5-2Q diameter 1.9 mm) and a 0.025 inch guide wire was used. In all cases sphincterotomy and/or sphincteroplasty was performed. The success rate was defined as the percentage of cases in which the biliary confluence could be reached with the ultrathin endoscope. Fifteen patients (8 men/7 women) were included. Mean age was 77.7 + or - 10.8 years (range 45-91). The indications for cholangioscopy were suspected bile duct stones (n = 9), electrohydraulic lithotripsy for the treatment of difficult choledocholithiasis (n = 5) and evaluation of biliary stricture (n = 1). Access to the bile duct was achieved in 14/15 cases (93.3%). Biliary confluence was reached in 13/15 cases (86.7%). One complication was observed in one patient (oxigen desaturation). DPC with an ultrathin endoscope can be done with the free-hand technique. Intraductal balloon-guided DPC allows full examination of the common bile duct in most cases.

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.

Scanning electron microscopy of real and artificial kidney stones before and after Thulium fiber laser ablation in air and water

NASA Astrophysics Data System (ADS)

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

2018-02-01

We investigated proposed mechanisms of laser lithotripsy, specifically for the novel, experimental Thulium fiber laser (TFL). Previous lithotripsy studies with the conventional Holmium:YAG laser noted a primary photothermal mechanism (vaporization). Our hypothesis is that an additional mechanical effect (fragmentation) occurs due to vaporization of water in stone material from high absorption of energy, called micro-explosions. The TFL irradiated calcium oxalate monohydrate (COM) and uric acid (UA) stones, as well as artificial stones (Ultracal30 and BegoStone), in air and water environments. TFL energy was varied to determine the relative effect on the ablation mechanism. Scanning electron microscopy (SEM) was used to study qualitative and characteristic changes in surface topography with correlation to presumed ablation mechanisms. Laser irradiation of stones in air produced charring and melting of the stone surface consistent with a photothermal effect and minimal fragmentation, suggesting no mechanical effect from micro-explosions. For COM stones ablated in water, there was prominent fragmentation in addition to recognized photothermal effects, supporting dual mechanisms during TFL lithotripsy. For UA stones, there were minimal photothermal effects, and dominant effects were mechanical. By increasing TFL pulse energy, a greater mechanical effect was demonstrated for both stone types. For artificial stones, there was no significant evidence of mechanical effects. TFL laser lithotripsy relies on two prominent mechanisms for stone ablation, photothermal and mechanical. Water is necessary for the mechanical effect which can be augmented by increasing pulse energy. Artificial stones may not provide a predictive model for mechanical effects during laser lithotripsy.

[Prospective evaluation of pain associated with indwelling JJ stents following ureterorenoscopic lithotripsy].

PubMed

Dudek, Przemysław; Gołabek, Tomasz; Jaskulski, Jarosław; Orłowski, Paweł; Bukowczan, Jakub; Szopiński, Tomasz; Chłosta, Piotr

2013-01-01

Routine placement of JJ ure teric stents, following uncomplicated endoscopic removal of a ureteral stone, still remains debatable. Indwelling JJ stents are not without any risks. They often can cause marked discomfort, or even pain. The aim of this study was to prospectively evaluate patient's perceived pain due to renal colic and indwelling JJ stent left following ure terorenoscopic lithotripsy (URSL). 54 patients with colicky pain due to distal ureteric stone, and who underwent uncompli cated ureterorenoscopic lithotripsy, were included in the study. Follow ing URSL, patients were randomly selected to have either JJ stent left in situ (Group I), or remain without a stent (Group II). Among all study par ticipants levels of pain prior, as well as 14 days after the procedure were evalu ated with the use of a visual analogue pain scale. Pain perception at the time of colic did not vary between men and women (6.30 +/- 1.33 and 6.38 +/- 1.11, respectively, p=0.293). Similarly, no differences in perceived pain were noted 14 days following URSL. Mean pain score in patients with indwelling JJ stent was 2.12 +/- 1.23 as compared to 2.15 +/- 0.67 in those without it (p=0.148). No increase in pain levels due to indwelling JJ stent could be observed. Further research to allow for better assessment of discomfort and pain caused by an indwelling JJ stent on a larger cohort, and which could also discriminate patients' psy chosomatic symptoms, is needed.

Endoscopic versus surgical drainage of the pancreatic duct in chronic pancreatitis.

PubMed

Cahen, Djuna L; Gouma, Dirk J; Nio, Yung; Rauws, Erik A J; Boermeester, Marja A; Busch, Olivier R; Stoker, Jaap; Laméris, Johan S; Dijkgraaf, Marcel G W; Huibregtse, Kees; Bruno, Marco J

2007-02-15

For patients with chronic pancreatitis and a dilated pancreatic duct, ductal decompression is recommended. We conducted a randomized trial to compare endoscopic and surgical drainage of the pancreatic duct. All symptomatic patients with chronic pancreatitis and a distal obstruction of the pancreatic duct but without an inflammatory mass were eligible for the study. We randomly assigned patients to undergo endoscopic transampullary drainage of the pancreatic duct or operative pancreaticojejunostomy. The primary end point was the average Izbicki pain score during 2 years of follow-up. The secondary end points were pain relief at the end of follow-up, physical and mental health, morbidity, mortality, length of hospital stay, number of procedures undergone, and changes in pancreatic function. Thirty-nine patients underwent randomization: 19 to endoscopic treatment (16 of whom underwent lithotripsy) and 20 to operative pancreaticojejunostomy. During the 24 months of follow-up, patients who underwent surgery, as compared with those who were treated endoscopically, had lower Izbicki pain scores (25 vs. 51, P<0.001) and better physical health summary scores on the Medical Outcomes Study 36-Item Short-Form General Health Survey questionnaire (P=0.003). At the end of follow-up, complete or partial pain relief was achieved in 32% of patients assigned to endoscopic drainage as compared with 75% of patients assigned to surgical drainage (P=0.007). Rates of complications, length of hospital stay, and changes in pancreatic function were similar in the two treatment groups, but patients receiving endoscopic treatment required more procedures than did patients in the surgery group (a median of eight vs. three, P<0.001). Surgical drainage of the pancreatic duct was more effective than endoscopic treatment in patients with obstruction of the pancreatic duct due to chronic pancreatitis. (Current Controlled Trials number, ISRCTN04572410 [controlled-trials.com].). Copyright 2007

[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

Proximal fiber tip damage during Holmium:YAG and thulium fiber laser ablation of kidney stones

NASA Astrophysics Data System (ADS)

Wilson, Christopher R.; Hardy, Luke A.; Irby, Pierce B.; Fried, Nathaniel M.

2016-02-01

The Thulium fiber laser (TFL) is being studied as an alternative to Holmium:YAG laser for lithotripsy. TFL beam originates within an 18-μm-core thulium doped silica fiber, and its near single mode, Gaussian beam profile enables transmission of higher laser power through smaller fibers than possible during Holmium laser lithotripsy. This study examines whether TFL beam profile also reduces proximal fiber tip damage compared to Holmium laser multimodal beam. TFL beam at wavelength of 1908 nm was coupled into 105-μm-core silica fibers, with 35-mJ energy, 500-μs pulse duration, and pulse rates of 50-500 Hz. For each pulse rate, 500,000 pulses were delivered. Magnified images of proximal fiber surfaces were taken before and after each trial. For comparison, 20 single-use, 270-μm-core fibers were collected after clinical Holmium laser lithotripsy procedures using standard settings (600 mJ, 350 μs, 6 Hz). Total laser energy, number of laser pulses, and laser irradiation time were recorded, and fibers were rated for damage. For TFL studies, output power was stable, and no proximal fiber damage was observed after delivery of 500,000 pulses at settings up to 35 mJ, 500 Hz, and 17.5 W average power. In contrast, confocal microscopy images of fiber tips after Holmium lithotripsy showed proximal fiber tip degradation in all 20 fibers. The proximal fiber tip of a 105-μm-core fiber transmitted 17.5 W of TFL power without degradation, compared to degradation of 270-μm-core fibers after transmission of 3.6 W of Holmium laser power. The smaller and more uniform TFL beam profile may improve fiber lifetime, and potentially reduce costs for the surgical disposables as well.

Complications associated with cervical endoscopic discectomy with the holmium laser.

PubMed

Haufe, Scott M W; Mork, Anthony R

2004-02-01

Our aim was to determine the rate of surgical complications associated with cervical endoscopic discectomy (CED). There are no studies that state the degree of complications after CED. Forty-one patients underwent CED with holmium laser. Two out of 41 patients incurred vascular compromise during the procedure. One patient developed recurrent laryngeal nerve damage. One patient developed discitis, and two patients complained of a "clicking" sensation postoperatively. Although CED has a relatively high success rate, there is a 15% rate of complications associated with the procedure. Most of the complications were minor (such as vascular compromise, recurrent laryngeal nerve injury, and postoperative "clicking" sensations), but there was one case of severe discitis, and there is the potential of serious complication from both vascular compromise and neural injury.

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.

Efficacy of combining flexible and rigid ureteroscopy for transurethral lithotripsy.

PubMed

Shigemura, Katsumi; Yasufuku, Tomihiko; Yamashita, Masuo; Arakawa, Soichi; Fujisawa, Masato

2010-08-23

Transurethral lithotripsy (TUL) is a common procedure in urology. However, controversy persists about how to deal with stones pushed up into kidney from the ureter during the procedure of TUL. This study investigated the efficacy of combining flexible ureteroscopy and rigid ureteroscopy for pushed-up stones into kidney during TUL. Fotry-one patients underwent TUL by a single surgeon from July 2007 to May 2009. Eight cases resulted in pushed-up stones during operation or involved existing kidney stones. We used a Zero-tip or Litho Catch Basket catheter and a flexible ureteroscope to carry these stones in kidney down into the ureter where the rigid ureteroscope could then reach and handle the stone for lithotripsy or being taken away. A Lithoclast system was used for lithotripsy. Five cases involved stones pushed up during surgery and 3 cases involved stones already in the kidney in detail. We pulled the stones down into the ureter in all cases and successfully completed lithotripsy or removed the stone, thus avoiding the performance of additional extracorporeal shock wave lithotripsy (ESWL). In conclusions, combined use of flexible ureteroscopy and rigid ureteroscopy for upper urinary tract stones pushed up into the kidney during TUL or renal stones could be useful for avoiding additional ESWL.

A novel stone retrieval basket for more efficient lithotripsy procedures.

PubMed

Salimi, N; Mahajan, A; Don, J; Schwartz, B

2009-01-01

This paper presents the development of an improved stone retrieval device that uses a newly designed cage of Nitinol wires encompassing a mesh basket made of a material that is laser resistant. Current methods to extract large stones involve imaging, using a laser to fragment the stones and then using existing cage-like baskets to trap the fragments individually and extracting them one at a time. These procedures are tedious, and may result in leaving some fragments behind that can reform causing the need for another procedure. The device presented in this paper will have a mesh-like sack which will consist of a laser resistant material of polytetrafluoroethylene (PTFE) enclosed within a newly designed Nitinol cage. Two alternate designs are provided for the cage in this paper. The handle of the device is revised to allow for a 3 Fr (1 mm) opening such that a laser's fiber optic cable can enter the device. Using this device a laser can be used to fragment the stone, and all the fragments are retained in the basket in both the design options. The basket can then be retracted allowing for the retrieval of all the fragments in one shot. The stone retrieval basket presented in this paper will significantly improve the efficiency and effectiveness of lithotripsy procedures for removal of large kidney and biliary tract stones.

Holographic high-resolution endoscopic image recording

NASA Astrophysics Data System (ADS)

Bjelkhagen, Hans I.

1991-03-01

Endoscopic holography or endoholography combines the features of endoscopy and holography. The purpose of endoholographic imaging is to provide the physician with a unique means of extending diagnosis by providing a life-like record of tissue. Endoholographic recording will provide means for microscopic examination of tissue and in some cases may obviate the need to excise specimens for biopsy. In this method holograms which have the unique properties of three-dimensionality large focal depth and high resolution are made with a newly designed endoscope. The endoscope uses a single-mode optical fiber for illumination and single-beam reflection holograms are recorded in close contact with the tissue at the distal end of the endoscope. The holograms are viewed under a microscope. By using the proper combinations of dyes for staining specific tissue types with various wavelengths of laser illumination increased contrast on the cellular level can be obtained. Using dyes such as rose bengal in combination with the 514. 5 nm line of an argon ion laser and trypan blue or methylene blue with the 647. 1 nm line of a krypton ion laser holograms of the stained colon of a dog showed the architecture of the colon''s columnar epithelial cells. It is hoped through chronological study using this method in-vivo an increased understanding of the etiology and pathology of diseases such as Crohn''s diseases colitis proctitis and several different forms of cancer will help

High-resolution imaging using endoscopic holography

NASA Astrophysics Data System (ADS)

Bjelkhagen, Hans I.

1990-08-01

Endoscopic holography or endoholography combines the features of endoscopy and holography. The purpose of endoholographic imaging is to provide the physician with a unique means of extending diagnosis by providing a life-like record of tissue. Endoholographic recording will provide means for microscopic examination of tissue and in some cases may obviate the need to excise specimens for biopsy. In this method holograms which have the unique properties of three-dimensionality large focal depth and high resolution are made with a newly designed endoscope. The endoscope uses a single-mode optical fiber for illumination and single-beam reflection holograms are recorded in close contact with the tissue at the distal end of the endoscope. The holograms are viewed under a microscope. By using the proper combinations of dyes for staining specific tissue types with various wavelengths of laser illumination increased contrast on the cellular level can be obtained. Using dyes such as rose bengal in combination with the 514. 5 nm line of an argon ion laser and trypan blue or methylene blue with the 647. 1 nm line of a krypton ion laser holograms of the stained colon of a dog showed the architecture of the colon''s columnar epithelial cells. It is hoped through chronological study using this method in-vivo an increased understanding of the etiology and pathology of diseases such as Crohn''s diseases colitis proctitis and several different forms of cancer will help to their control. 1.

Photoactive dye-enhanced tissue ablation for endoscopic laser prostatectomy.

PubMed

Ahn, Minwoo; Hau, Nguyen Trung; Van Phuc, Nguyen; Oh, Junghwan; Kang, Hyun Wook

2014-11-01

Laser light has been widely used as a surgical tool to treat benign prostate hyperplasia (BPH) over 20 years. Recently, application of high laser power up to 200 W was often reported to swiftly remove a large amount of prostatic tissue. The purpose of this study was to validate the feasibility of photoactive dye injection to enhance light absorption and eventually to facilitate tissue vaporization with low laser power. Chicken breast tissue was selected as a target tissue due to minimal optical absorption at the visible wavelength. Four biocompatible photoactive dyes, including amaranth (AR), black dye (BD), hemoglobin powder (HP), and endoscopic marker (EM), were selected and tested in vitro with a customized 532 nm laser system with radiant exposure ranging from 0.9 to 3.9 J/cm(2) . Light absorbance and ablation threshold were measured with UV-Vis spectrometer and Probit analysis, respectively, and compared to feature the function of the injected dyes. Ablation performance with dye-injection was evaluated in light of radiant exposure, dye concentration, and number of injection. Higher light absorption by injected dyes led to lower ablation threshold as well as more efficient tissue removal in the order of AR, BD, HP, and EM. Regardless of the injected dyes, ablation efficiency principally increased with radiant exposure, dye concentration, and number of injection. Among the dyes, AR created the highest ablation rate of 44.2 ± 0.2 µm/pulse due to higher absorbance and lower ablation threshold. High aspect ratios up to 7.1 ± 0.4 entailed saturation behavior in the tissue ablation injected with AR and BD, possibly resulting from plume shielding and increased scattering due to coagulation. Preliminary tests on canine prostate with a hydraulic injection system demonstrated that 80 W with dye injection yielded comparable ablation efficiency to 120 W with no injection, indicating 33% reduced laser power with almost equivalent performance. Due to

[Treatment of kidney stones using shock-wave lithotripsy with sonographic control].

PubMed

Benes, J; Chmel, J; Simon, V; Stuka, C; Flejsar, P

1991-10-01

Lithotripsy by means of an extracorporeal shock-wave was performed in 128 patients with urolithiasis. In this group for the first time in Czechoslovakia ultrasound control of kidney stones was used in 44 patients; in the remainder X-ray control was used. The authors used equipment designed and manufactured locally. The ultrasonic probe is laterally connected with the shock-wave applicator. Disappearance of the fragments after lithotripsy was achieved in 39 patients where ultrasonic control was used. The paper presents the results, discusses the advantages and limitations of ultrasonic control in extracorporeal lithotripsy of urolithiasis.

[Treatment of kidney calculi using shock-wave lithotripsy with ultrasonic guidance].

PubMed

Benes, J; Chmel, J; Simon, V; Stuka, C; Flejsar, P

1991-01-01

Lithotripsy by means of an extracorporeal shock-wave was performed in 128 patients with urolithiasis. In this group for the first time in Czechoslovakia ultrasound control of kidney stones was used in 44 patients; in the remainder X-ray control was used. The authors used equipment designed and manufactured locally. The ultrasonic probe is laterally connected with the shock-wave applicator. Disappearance of the fragments after lithotripsy was achieved in 39 patients where ultrasonic control was used. The paper presents the results, discusses the advantages and limitations of ultrasonic control in extracorporeal lithotripsy of urolithiasis.

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

Single- and double-balloon enteroscopy-assisted endoscopic retrograde cholangiopancreatography in patients with Roux-en-Y plus hepaticojejunostomy anastomosis and Whipple resection.

PubMed

Itokawa, Fumihide; Itoi, Takao; Ishii, Kentaro; Sofuni, Atsushi; Moriyasu, Fuminori

2014-04-01

In patients with Roux-en-Y hepaticojejunostomy (HJ with R-Y) and Whipple resection, endoscopic retrograde cholangiopancreatography (ERCP) can be challenging. We report our experience with ERCP using balloon-assisted enteroscopy (BAE) (BAE-ERCP) in patients with HJ with R-Y, and Whipple resection. BAE-ERCP procedures were carried out in 62 patients (HJ with R-Y:Whipple resection=34:28). Overall, the rates of reaching the anastomosis were 85.3% (29/34) in HJ with R-Y and 96.4% (27/28) in Whipple resection. In terms of HJ with R-Y, insertion success rate by standard single-balloon enteroscopy (SBE) was 89.3% (25/28). Insertion success rate by short BAE, including SBE and double-balloon enteroscopy (DBE), was 50% (3/6). There was a statistically significant difference of insertion success rate between standard long BE and short BE (P=0.021). However, in the Whipple patients, insertion success rate by standard and short SBE was 93.8% (15/16) and 91.7% (11/12), respectively. Initial insertion success rate by short BAE in Whipple patients was significantly higher than in HJ with R-Y (91.7% vs 50%, P=0.045). Therapeutic interventions included dilation of anastomosis stricture, stone extraction, endoscopic mechanical lithotripsy, biliary stent placement, stent extraction, endoscopic nasobiliary drainage, direct cholangioscopy, and electrohydraulic lithotripsy. Our HJ with R-Y series and Whipple series treatment success rate was 90% (18/20) and 95.0% (19/20), respectively. BAE-ERCP enabled ERCP to be carried out in patients with HJ. It is considered safe and feasible. Further experience and device improvement are needed. © 2014 The Authors. Digestive Endoscopy © 2014 Japan Gastroenterological Endoscopy Society.

Does extracorporeal shock wave lithotripsy cause hearing impairment in children?

PubMed

Tuncer, Murat; Sahin, Cahit; Yazici, Ozgur; Kafkasli, Alper; Turk, Akif; Erdogan, Banu A; Faydaci, Gokhan; Sarica, Kemal

2015-03-01

We evaluated the possible effects of noise created by high energy shock waves on the hearing function of children treated with extracorporeal shock wave lithotripsy. A total of 65 children with normal hearing function were included in the study. Patients were divided into 3 groups, ie those becoming stone-free after 1 session of shock wave lithotripsy (group 1, 22 children), those requiring 3 sessions to achieve stone-free status (group 2, 21) and healthy children/controls (group 3, 22). Extracorporeal shock wave lithotripsy was applied with patients in the supine position with a 90-minute frequency and a total of 2,000 shock waves in each session (Compact Sigma, Dornier MedTech, Wessling, Germany). Second energy level was used with a maximum energy value of 58 joules per session in all patients. Hearing function and possible cochlear impairment were evaluated by transient evoked otoacoustic emissions test at 1.0, 1.4, 2.0, 2.8 and 4.0 kHz frequencies before the procedure, 2 hours later, and 1 month after completion of the first shock wave lithotripsy session in groups 1 and 2. In controls the same evaluation procedures were performed at the beginning of the study and 7 weeks later. Regarding transient evoked otoacoustic emissions data, in groups 1 and 2 there was no significant alteration in values obtained after shock wave lithotripsy compared to values obtained at the beginning of the study, similar to controls. A well planned shock wave lithotripsy procedure is a safe and effective treatment in children with urinary stones and causes no detectable harmful effect on hearing function. Copyright © 2015 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

New application system for laser and ultrasonic therapy in endoscopic surgery

NASA Astrophysics Data System (ADS)

Desinger, Kai; Helfmann, Juergen; Stein, Thomas; Mueller, Gerhard J.

1996-12-01

Flexible acoustic waveguides for selective tissue fragmentation are not yet commercially available. Experimental studies have shown the possibility of transmission of acoustical transients via optical silica glass fibers. The aim of this project is the development of a new endoscopic application system that would enable surgeons to use the laser and the ultrasound technique for therapy simultaneously. The concept of this application system is based on the transmission of laser radiation and ultrasound power via flexible silica glass fibers. Theoretical and experimental results on the feasibility of such an application system for an ultrasonic power delivery system are presented. Piezo-electric transducers are used to provide a high efficiency in generating the ultrasonic power. With reference to the CUSA-technique, a special flexible guiding system has been designed for providing aspiration at the tip and for protection of the fiber. The system transmits via an optical fiber up to 100 Watt Nd:YAG laser radiation. The axial oscillation of the fiber tip is +/- micrometers at a frequency of 27 kHz. First results of in vitro experiments are presented. The parenchymatous cells of liver can be fragmented without destruction of the collagenous matrix. The laser can be optionally used to coagulate bleedings or to cut collagenous tissues in contact. Applications for an acoustical and optical waveguide in ultrasonic surgery are demonstrated. This new approach in developing a first application system for the therapeutical use of laser radiation and power ultrasound in minimal invasive surgery via optical waveguides offers new possibilities in surgery. The laser ultrasonic surgical therapy (LUST) with its thin and flexible applicator provides new working fields especially for neuro or liver surgery. The tip can be bent and thus areas which could not be treated before have now been made accessible. Without changing the instrumentation, the surgeon can use the laser for tissue

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.

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

Endoscopic treatment of malignant airway obstructions in 2,008 patients.

PubMed

Cavaliere, S; Venuta, F; Foccoli, P; Toninelli, C; La Face, B

1996-12-01

We report our 13-year experience with endoscopic treatment of malignant obstructions of the airway by Nd:YAG laser, stents, and intraluminal brachytherapy in 2,008 patients. We performed 2,610 laser resections in 1,838 patients, 66 high dose rate brachytherapies, and we placed 393 tracheobronchial silicone stents in 306 patients. We used the rigid bronchoscope in 96% of the laser procedures and in all cases requiring stent placement; general anesthesia was given to 90% of these patients. Endobronchial radiotherapy was performed under local, anesthesia. In 93% of patients undergoing laser resection, we obtained an immediate patency of the airway with consequent improvement of quality of life. The median time between the first and second laser treatment was 102 days, being longer in the case of stent placement (when required) or in association with brachytherapy. Even if endoscopic treatment should be considered only for palliation, laser vaporization could be curative in case of in situ carcinoma. Since 1983, we have treated 23 such lesions in 17 patients and up to now, none has recurred. Finally, endoscopic resection may allow a better assessment of the true extent of the tumor, shifting to surgery patients originally considered to have inoperable disease or allowing lung-sparing operations (21 and 18 patients of our series, respectively). The total mortality rate was 0.4% (12 patients over 2,798 treatments; 2,710 Nd:YAG laser + 151 stents without laser + 37 brachytherapies without laser) in the first week after the procedures, and was mainly related to cardiovascular problems and respiratory failure. In conclusion, endoscopic resection of lung malignancies is rapid, effective, repeatable, and complementary to other treatments; although it should be considered only palliative, laser resection could be curative in patients with in situ carcinomas and early cancers. Laser, stents, and endoluminal brachytherapy should be available in all centers with major experience

Intraluminal pneumatic lithotripsy for the removal of encrusted urinary catheters.

PubMed

Canby-Hagino, E D; Caballero, R D; Harmon, W J

1999-12-01

Urologists frequently treat patients requiring long-term urinary drainage with a percutaneous nephrostomy tube or ureteral stent. When such tubes are neglected and become encrusted, removal challenges even experienced urologists. We describe a new, minimally invasive technique for safely and rapidly removing encrusted, occluded tubes using the Swiss Lithoclast pneumatic lithotriptor. Patients presenting with an encrusted urinary catheter were evaluated by excretory urography for renal function and obstruction. Gentle manual extraction of the tube was attempted, followed by traditional extracorporeal shock wave lithotripsy and/or ureteroscopy. When the tube was not extracted, patients were then treated with intraluminal insertion of a pneumatic lithotripsy probe. One patient presented with an encrusted, occluded nephrostomy tube and 2 had an encrusted, occluded, indwelling ureteral stent. None was removed by manual traction. Intraluminal encrustations prevented the pigtail portions of these tubes from uncoiling and removal. In each case a pneumatic lithotripsy probe was inserted into the lumen of the catheter and advanced in a jackhammer-like fashion. This technique resulted in disruption of the intraluminal encrustations and straightening of the tubes so that they were removed in an atraumatic manner. Intraluminal pneumatic lithotripsy is a safe, easy and rapid technique for removing encrusted urinary catheters. It is unique in that the pneumatic lithotripsy probe functions in an aqueous and nonaqueous environment, and dislodges intraluminal calcifications. We recommend its use as first line treatment for removing encrusted urinary catheters.

Endoscopic management of chronic radiation proctitis

PubMed Central

Rustagi, Tarun; Mashimo, Hiroshi

2011-01-01

Chronic radiation proctopathy occurs in 5%-20% of patients following pelvic radiotherapy. Although many cases resolve spontaneously, some lead to chronic symptoms including diarrhea, tenesmus, urgency and persistent rectal bleeding with iron deficiency anemia requiring blood transfusions. Treatments for chronic radiation proctitis remain unsatisfactory and the basis of evidence for various therapies is generally insufficient. There are very few controlled or prospective trials, and comparisons between therapies are limited because of different evaluation methods. Medical treatments, including formalin, topical sucralfate, 5-amino salicylic acid enemas, and short chain fatty acids have been used with limited success. Surgical management is associated with high morbidity and mortality. Endoscopic therapy using modalities such as the heater probe, neodymium:yttrium-aluminium-garnet laser, potassium titanyl phosphate laser and bipolar electrocoagulation has been reported to be of some benefit, but with frequent complications. Argon plasma coagulation is touted to be the preferred endoscopic therapy due to its efficacy and safety profile. Newer methods of endoscopic ablation such as radiofrequency ablation and cryotherapy have been recently described which may afford broader areas of treatment per application, with lower rate of complications. This review will focus on endoscopic ablation therapies, including such newer modalities, for chronic radiation proctitis. PMID:22147960

Endoscopic management of chronic radiation proctitis.

PubMed

Rustagi, Tarun; Mashimo, Hiroshi

2011-11-07

Chronic radiation proctopathy occurs in 5%-20% of patients following pelvic radiotherapy. Although many cases resolve spontaneously, some lead to chronic symptoms including diarrhea, tenesmus, urgency and persistent rectal bleeding with iron deficiency anemia requiring blood transfusions. Treatments for chronic radiation proctitis remain unsatisfactory and the basis of evidence for various therapies is generally insufficient. There are very few controlled or prospective trials, and comparisons between therapies are limited because of different evaluation methods. Medical treatments, including formalin, topical sucralfate, 5-amino salicylic acid enemas, and short chain fatty acids have been used with limited success. Surgical management is associated with high morbidity and mortality. Endoscopic therapy using modalities such as the heater probe, neodymium:yttrium-aluminium-garnet laser, potassium titanyl phosphate laser and bipolar electrocoagulation has been reported to be of some benefit, but with frequent complications. Argon plasma coagulation is touted to be the preferred endoscopic therapy due to its efficacy and safety profile. Newer methods of endoscopic ablation such as radiofrequency ablation and cryotherapy have been recently described which may afford broader areas of treatment per application, with lower rate of complications. This review will focus on endoscopic ablation therapies, including such newer modalities, for chronic radiation proctitis.

Automatic Tracking Algorithm in Coaxial Near-Infrared Laser Ablation Endoscope for Fetus Surgery

NASA Astrophysics Data System (ADS)

Hu, Yan; Yamanaka, Noriaki; Masamune, Ken

2014-07-01

This article reports a stable vessel object tracking method for the treatment of twin-to-twin transfusion syndrome based on our previous 2 DOF endoscope. During the treatment of laser coagulation, it is necessary to focus on the exact position of the target object, however it moves by the mother's respiratory motion and still remains a challenge to obtain and track the position precisely. In this article, an algorithm which uses features from accelerated segment test (FAST) to extract the features and optical flow as the object tracking method, is proposed to deal with above problem. Further, we experimentally simulate the movement due to the mother's respiration, and the results of position errors and similarity verify the effectiveness of the proposed tracking algorithm for laser ablation endoscopy in-vitro and under water considering two influential factors. At average, the errors are about 10 pixels and the similarity over 0.92 are obtained in the experiments.

Thulium fiber laser ablation of kidney stones using a 50-μm-core silica optical fiber

NASA Astrophysics Data System (ADS)

Blackmon, Richard L.; Hutchens, Thomas C.; Hardy, Luke A.; Wilson, Christopher R.; Irby, Pierce B.; Fried, Nathaniel M.

2015-01-01

Our laboratory is currently studying the experimental thulium fiber laser (TFL) as a potential alternative laser lithotripter to the gold standard, clinical Holmium:YAG laser. We have previously demonstrated the efficient coupling of TFL energy into fibers as small as 100-μm-core-diameter without damage to the proximal end. Although smaller fibers have a greater tendency to degrade at the distal tip during lithotripsy, fiber diameters (≤200 μm) have been shown to increase the saline irrigation rates through the working channel of a flexible ureteroscope, to maximize the ureteroscope deflection, and to reduce the stone retropulsion during laser lithotripsy. In this study, a 50-μm-core-diameter, 85-μm-outer-diameter, low-OH silica fiber is characterized for TFL ablation of human calcium oxalate monohydrate urinary stones, ex vivo. The 50-μm-core fiber consumes approximately 30 times less cross-sectional area inside the single working channel of a ureteroscope than the standard 270-μm-core fiber currently used in the clinic. The ureteroscope working channel flow rate, including the 50-μm fiber, decreased by only 10% with no impairment of ureteroscope deflection. The fiber delivered up to 15.4±5.9 W under extreme bending (5-mm-radius) conditions. The stone ablation rate measured 70±22 μg/s for 35-mJ-pulse-energy, 500-μs-pulse-duration, and 50-Hz-pulse-rate. Stone retropulsion and fiber burnback averaged 201±336 and 3000±2600 μm, respectively, after 2 min. With further development, thulium fiber laser lithotripsy using ultra-small, 50-μm-core fibers may introduce new integration and miniaturization possibilities and potentially provide an alternative to conventional Holmium:YAG laser lithotripsy using larger fibers.

Invasive fungal bezoar requiring partial cystectomy.

PubMed

Sundi, Debasish; Tseng, Kenneth; Mullins, Jeffrey K; Marr, Kieren A; Hyndman, Matthew Eric

2012-02-01

A 67-year-old man developed dysuria and position-dependent obstructive voiding symptoms after undergoing holmium laser ablation of the prostate (HOLAP) for benign prostatic hypertrophy. A large fungal (candidal) ball adherent to the bladder wall was removed by loop excision, but the bezoar recurred in 2 weeks despite systemic fluconazole and intravesical amphotericin B. A second attempt at endoscopic removal with ultrasonic lithotripsy, endoscopic graspers, and fulguration was also unsuccessful. The patient underwent open partial cystectomy to remove his invasive fungal bezoar. Convalescence was unremarkable. Urinalysis, culture, and follow-up cystoscopy after partial cystectomy demonstrated successful definitive treatment of the fungal ball. Copyright © 2012 Elsevier Inc. All rights reserved.

Present-day potentialities of endoscopic diagnostics and treatment of early cancer in respiratory and digestive tracts

NASA Astrophysics Data System (ADS)

Sokolov, Victor V.; Zharkova, Natalia N.; Filonenko, E. V.; Telegina, L. V.; Karpova, E. S.

1999-12-01

The paper presents the latest potentialities of the endoscopic fluorescent diagnostics as well as endoscopic electric-, laser surgery and photodynamic therapy (PDT) of the early cancer in the respiratory and digestive tracts. We present in detail indication and factors determining the application of the endoscopic resection of the tumor. The advantages of the combination application of PDT, electro-, Nd:YAG laser surgery and brachitherapy are stressed. The near and remote results of endoscopic treatment of the early cancer in larynx (37), lung (109), esophagus (39) and stomach (58) are shown.

Extracorporeal shockwave lithotripsy of distal ureteral calculi.

PubMed

Miller, K; Bubeck, J R; Hautmann, R

1986-01-01

To date, the use of extracorporeal shockwave lithotripsy (ESWL) has been limited to renal calculi and ureteral calculi above the pelvic brim. Modifying the position of the patient on the support of the Dornier lithotripter HM3, we were able to localize and treat distal ureteral calculi. Until April 1986, 43 patients with stones in the lower ureter underwent contact-free lithotripsy. Treatment was successful in 39 patients (90%), 2 of these requiring 2 sessions. In 4 patients treatment failed and stone removal was accomplished using ureteroscopy or open surgery. No complications or adverse side effects were encountered in the whole series. ESWL is now the method of choice for the treatment of distal ureteral calculi in our department.

Voice quality after endoscopic laser surgery and radiotherapy for early glottic cancer: objective measurements emphasizing the Voice Handicap Index

PubMed Central

Caminero Cueva, Maria Jesús; Señaris González, Blanca; Llorente Pendás, José Luis; Gorriz Gil, Carmen; López Llames, Aurora; Alonso Pantiga, Ramón; Suárez Nieto, Carlos

2007-01-01

We analyzed the functional outcome and self-evaluation of the voice of patients with T1 glottic carcinoma treated with endoscopic laser surgery and radiotherapy. We performed an objective voice evaluation, as well as a physical, emotional and functional well being assessment of 19 patients treated with laser surgery and 18 patients treated with radiotherapy. Voice quality is affected both by surgery and radiotherapy. Voice parameters only show differences in the maximum phonation time between both treatments. Results in the Voice Handicap Index show that radiotherapy has less effect on patient voice quality perception. There is a reduced impact on the patient’s perception of voice quality after radiotherapy, despite there being no significant differences in vocal quality between radiotherapy and laser cordectomy. PMID:17999074

Treatment philosophy and retreatment rates following piezoelectric lithotripsy.

PubMed

Fegan, J; Camp, L A; Wilson, W T; Miller, G L; Preminger, G M

1993-01-01

Second generation lithotriptors offer the advantage of anesthesia-free fragmentation of renal and ureteral calculi but they frequently require multiple treatments to attain a stone-free status. However, excessive single lithotripsy sessions or multiple treatments may be associated with significant damage to the kidney. For some clinicians a common treatment philosophy involves evaluation of serial plain abdominal films every 24 hours after lithotripsy and immediate retreatment of all patients with incomplete fragmentation. To avoid unnecessary retreatments and, thus, minimize potential renal damage, we prospectively evaluated 100 patients undergoing lithotripsy on a Wolf Piezolith 2300 device. Patients were routinely treated with 4,000 shocks at 1,100 bar. Serial plain abdominal films were obtained at 1 day and 2 weeks after lithotripsy. The need for retreatment was determined by the plain abdominal film results. Additional therapy was considered necessary if there was no stone fragmentation or if residual fragments measured greater than 4 mm. Of the patients whose plain abdominal film at 24 hours indicated the need for a repeat treatment 43% were stone-free on the 2-week film. Thus, these patients were spared an unnecessary treatment by allowing adequate time for the stone fragments to pass spontaneously. Our data suggest that repeat treatments on second generation lithotriptors should not be performed within 24 hours. Rather, the patient should be reevaluated at least 1 to 2 weeks later to avoid unnecessary retreatment with the attendant potential for renal injury. In addition, when comparing the retreatment rates of various lithotriptors, one should also consider the treatment philosophy used at the particular institution and the timing of the radiographic studies used to determine the stone-free status.

New laser soldering-based closures: a promising method in natural orifice transluminal endoscopic surgery.

PubMed

Bogni, Serge; Ortner, Maria-Anna; Vajtai, Istvan; Jost, Christian; Reinert, Michael; Dallemagne, Bernard; Frenz, Martin

2012-07-01

Complete closure of gastrotomy is the linchpin of safe natural orifice transgastric endoscopic surgery. To evaluate feasibility and efficacy of a new method of gastrotomy closure by using a sutureless laser tissue-soldering (LTS) technique in an ex vivo porcine stomach. In vitro experiment. Experimental laboratory. Histological analysis and internal and external liquid pressure with and without hydrochloric acid exposure were determined comparing gastrotomy closure with LTS and with hand-sewn surgical sutures. Comparison of LTS and hand-sewn surgical gastrotomy closure. The primary outcome parameter was the internal leak pressure. Secondary parameters were the difference between internal and external leak pressures, the impact of an acid environment on the device, histological changes, and feasibility of endoscopic placement. The internal liquid leak pressure after LTS was almost twice as high as after hand-sewn surgical closure (416 ± 53 mm Hg vs 229 ± 99 mm Hg; P = .01). The internal leak pressure (416 ± 53 mm Hg) after LTS was higher than the external leak pressure (154 ± 46 mm Hg; P < .0001). An acidic environment did not affect leak pressure after LTS. Endoscopic LTS closure was feasible in all experiments. Histopathology revealed only slight alterations beneath the soldering plug. In vitro experiments. Leak pressure after LTS closure of gastrotomy is higher than after hand-sewn surgical closure. LTS is a promising technique for closure of gastrotomies and iatrogenic perforations. Further experiments, in particular survival studies, are mandatory. Copyright © 2012 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.

Preventing stone retropulsion during intracorporeal lithotripsy.

PubMed

Elashry, Osama M; Tawfik, Ahmad M

2012-12-01

Several studies of ureteroscopic treatment for ureteral stones have reported that most stone clearance failures can be attributed to stone fragment retropulsion. Stone retropulsion can result in increased operative time and cost-resulting from the need to change from the semi-rigid ureteroscope to a flexible instrument to chase migrated calculi-and additional procedures to treat residual migrated fragments are often required. The degree of migration depends mainly on the energy source used for lithotripsy; pneumatic and electrohydraulic lithotripters are associated with a greater degree of retropulsion than lasers. Different stone-trapping strategies and devices have been developed to minimize stone migration. Novel devices include the Lithovac(®) suction device, the Passport(™) balloon, the Stone Cone(™), the PercSys Accordion(®), the NTrap(®), and stone baskets such as the LithoCatch(™), the Parachute(™), and the Escape(®). Some authors have also reported on the use of lubricating jelly and BackStop(®) gel (a reverse thermosensitive polymeric plug); these devices are instilled proximal to the stone prior to the application of kinetic energy in order to prevent retrograde stone migration.

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

Micromotor endoscope catheter for in vivo, ultrahigh-resolution optical coherence tomography.

PubMed

Herz, P R; Chen, Y; Aguirre, A D; Schneider, K; Hsiung, P; Fujimoto, J G; Madden, K; Schmitt, J; Goodnow, J; Petersen, C

2004-10-01

A distally actuated, rotational-scanning micromotor endoscope catheter probe is demonstrated for ultrahigh-resolution in vivo endoscopic optical coherence tomography (OCT) imaging. The probe permits focus adjustment for visualization of tissue morphology at varying depths with improved transverse resolution compared with standard OCT imaging probes. The distal actuation avoids nonuniform scanning motion artifacts that are present with other probe designs and can permit a wider range of imaging speeds. Ultrahigh-resolution endoscopic imaging is demonstrated in a rabbit with <4-microm axial resolution by use of a femtosecond Cr:forsterite laser light source. The micromotor endoscope catheter probe promises to improve OCT imaging performance in future endoscopic imaging applications.

Micromotor endoscope catheter for in vivo, ultrahigh-resolution optical coherence tomography

NASA Astrophysics Data System (ADS)

Herz, P. R.; Chen, Y.; Aguirre, A. D.; Schneider, K.; Hsiung, P.; Fujimoto, J. G.; Madden, K.; Schmitt, J.; Goodnow, J.; Petersen, C.

2004-10-01

A distally actuated, rotational-scanning micromotor endoscope catheter probe is demonstrated for ultrahigh-resolution in vivo endoscopic optical coherence tomography (OCT) imaging. The probe permits focus adjustment for visualization of tissue morphology at varying depths with improved transverse resolution compared with standard OCT imaging probes. The distal actuation avoids nonuniform scanning motion artifacts that are present with other probe designs and can permit a wider range of imaging speeds. Ultrahigh-resolution endoscopic imaging is demonstrated in a rabbit with <4-µm axial resolution by use of a femtosecond Crforsterite laser light source. The micromotor endoscope catheter probe promises to improve OCT imaging performance in future endoscopic imaging applications.

[Non-biological 3D printed simulator for training in percutaneous nephro- lithotripsy].

PubMed

Alyaev, Yu G; Sirota, E S; Bezrukov, E A; Ali, S Kh; Bukatov, M D; Letunovskiy, A V; Byadretdinov, I Sh

2018-03-01

To develop a non-biological 3D printed simulator for training and preoperative planning in percutaneous nephrolithotripsy (PCNL), which allows doctors to master and perform all stages of the operation under ultrasound and fluoroscopy guidance. The 3D model was constructed using multislice spiral computed tomography (MSCT) images of a patient with staghorn urolithiasis. The MSCT data were processed and used to print the model. The simulator consisted of two parts: a non-biological 3D printed soft model of a kidney with reproduced intra-renal vascular and collecting systems and a printed 3D model of a human body. Using this 3D printed simulator, PCNL was performed in the interventional radiology operating room under ultrasound and fluoroscopy guidance. The designed 3D printed model of the kidney completely reproduces the individual features of the intra-renal structures of the particular patient. During the training, all the main stages of PCNL were performed successfully: the puncture, dilation of the nephrostomy tract, endoscopic examination, intra-renal lithotripsy. Our proprietary 3D-printed simulator is a promising development in the field of endourologic training and preoperative planning in the treatment of complicated forms of urolithiasis.

New application system for simultaneous laser and ultrasonic transmission in endoscopic surgery (LUST)

NASA Astrophysics Data System (ADS)

Desinger, Kai; Helfmann, Juergen; Stein, Thomas; Liebold, K.; Mueller, Gerhard J.

1998-04-01

A new combined Laser and Ultrasound Surgical Therapy (LUST) device for an endoscopically suitable coagulation and tissue fragmentation based on the transmission of laser radiation and ultrasound via flexible silica glass fibers was developed at the LMTB. The ultrasound tissue interaction is based on the well-known CUSA-technology, which enables the surgeon to cut various types of tissue with different degrees of effectiveness. This selective cutting performance is a very useful feature, e.g. for a brain tumor extirpation, where it must be guaranteed that vessels and nerves are not affected while ensuring a fast reduction of the tumor mass. Application fields are in oncology, neurosurgery and angioplasty. The laser radiation can be used for tissue coagulation purposes and homeostasis. With a fiber based LUST-system working at a resonance frequency of 30 kHz, using a laser-vibrometer, velocity amplitudes of up to 20 m/s could be detected at the distal end which corresponds to an elongation of more than 100 micrometers . The investigations have shown that the velocity amplitude, next to suction, frequency and cross section of the active fiber tip, has the greatest impact on the fragmentation rate. With a suction setting of 5 W, the following tissue fragmentation rates could be achieved with a 1.3 mm2 fiber cross section and a tip amplitude velocity of 12 m/s: brain tissue 50 mg/s, liver 4,5 mg/s and kidney 4 mg/s. Laser radiation up to 25 watt was sufficient to coagulate soft tissue. This new approach in developing an application system for the therapeutical use of laser radiation and ultrasound via optical waveguides offers new possibilities in minimally invasive surgery, providing a complete new working sphere for the surgeon. The flexible opto-acoustic waveguide (400 - 1700 micrometers ) can be bent making areas accessible which were inaccessible before. The surgeon can use the laser radiation for tissue coagulation or cutting and the ultrasound for tissue

An effective technique to facilitate radiographic stone visualization with an internal stent during shock wave lithotripsy.

PubMed

Sundaram, C P; Saltzman, B

1998-10-01

We describe a simple method to assist stone localization during shock wave lithotripsy in the presence of a Double J stent. A 4F whistle tip ureteral catheter is passed alongside a previously inserted 6F Double J stent. The tip of the ureteral stent is positioned in the lower or mid third of the ureter. Contrast material is injected through the ureteral catheter during lithotripsy to assist stone localization. This technique has been successful in localization of poorly opacified renal stones during lithotripsy. Radiolucent and poorly calcified renal stones can be easily localized during shock wave lithotripsy, despite the presence of a Double J stent. No special catheters or stents are required for this technique.

Lasers in digestive endoscopy

NASA Astrophysics Data System (ADS)

Brunetaud, Jean Marc; Maunoury, Vincent; Cochelard, Dominique

1997-01-01

Lasers were introduced in digestive endoscopy to stop active gastroduodenal hemorrhages. Their use spread progressively to the treatment of chronic hemorrhages from vascular malformations and sessile tumors. Laser face competition from other endoscopic techniques such as electrocoagulation, injection techniques, dilation, stents, and brachytherapy. Many series have reported the efficacy of lasers in digestive endoscopy used for their thermal or photochemical effects. However, they were gradually abandoned for the treatment of hemorrhages because of competition from nonlaser techniques. Lasers are still used for ablation of sessile tumors, but their true impact is difficult to evaluate. Modern methods of technology assessment did not allow gastroenterologists to clearly define the place of lasers among surgery, radio-chemotherapy, and other endoscopic techniques, and data on the daily use of lasers are not available. Therefore, the conclusion can only be subjective. The best current application of thermal lasers appears to be in the treatment of rectosigmoid villous adenomas in elderly patients. Small superficial rectal cancers may also become a good subject due to the impact of endoscopic ultrasonography. Early lesions with multifocal or diffuse disease such as early esophageal cancers could be the most promising subject of application for photodynamic therapy in the future.

Holmium:YAG surgical lasers.

PubMed

1995-03-01

"Holmium:YAG (Ho:YAG)" is the shorthand name for a family of solid-state lasers that use the doping element holmium in a laser crystal (e.g., YAG [yttrium-aluminum-garnet]) and that emit energy at approximately 2.1 microns. This wavelength is relatively new to medicine and has been used in laser surgery for only about the last six years. Like the carbon dioxide (CO2) laser when it was first used clinically, the Ho:YAG laser is poised for rapid and wide-spread use. Ho:YAG lasers, like CO2 lasers, offer precise cutting with minimal damage to adjacent tissue; however, unlike CO2 lasers, they also offer fiberoptic delivery (which is ideal for endoscopic use) and the ability to treat tissue in a liquid-filled environment (e.g., saline, blood). The initial specialty for which the Ho:YAG laser was used was arthroscopic surgery, especially diskectomy. Today, it is effectively used in many surgical specialties, including general surgery, urology, laparoscopy, neurosurgery, lithotripsy, angioplasty, orthopedic surgery (which includes procedures such as meniscectomy, bone sculpting [may also be performed in plastic surgery], and some experimental surgery, such as cartilage shrinking to tighten loose joints), and dentistry. Because of its broad range of potential applications, it has been called the "Swiss Army Knife" of lasers. High-powered Ho:YAG lasers, which enable surgeons to work more quickly and cut more smoothly, have been made available only within the last three years (units offering > 20 W) to 18 months (units offering > 60 W). Because of this rapid increase, high-powered units are still relatively expensive, and it is not yet clear whether maximum power outputs will continue to increase or whether the cost of higher-power units will begin to come down. Although low-power and high-power Ho:YAG lasers can be used for the same procedures, their different ranges of possible clinical techniques make them better suited to different applications: low-power units are

Extracorporeal Shock Wave Lithotripsy for Chinese Patients With Pancreatic Stones: A Prospective Study of 214 Cases.

PubMed

Hu, Liang-Hao; Ye, Bo; Yang, Yu-Guang; Ji, Jun-Tao; Zou, Wen-Bin; Du, Ting-Ting; Hao, Jun-Feng; Jiang, Ying-Yi; Liao, Zhuan; Li, Zhao-Shen

2016-02-01

This study aims to evaluate prospectively the safety and efficacy of extracorporeal shock wave lithotripsy (ESWL) in Chinese patients. A total of 214 patients with painful chronic pancreatitis and pancreatic stones who underwent ESWL followed by endoscopic retrograde cholangiopancreatography from March 2011 to February 2012 in Changhai Hospital were enrolled. The main pancreatic duct clearance rate and complications were recorded prospectively. Symptoms, weight, quality of life, and pancreatic function were assessed before and after ESWL and endotherapy. A total of 473 ESWL procedures were performed in 214 patients. Stones were fragmented in all cases. Complete clearance of main pancreatic duct stones and successful endoscopic decompression were achieved in 155 (72.4%) and 188 (90.8%) of 214 patients, respectively. Complications were observed after 20 sessions (20 of 473, 4.23%). Follow-up (n = 195) after 18.5 ± 3.3 months showed that complete and partial pain relief were achieved in 71.3% and 24.0% of the patients, respectively. The scores for the quality of life (5.8 ± 1.7 vs 8.1 ± 1.2, P < 0.05) and mental health from the Medical Outcomes Study 36-Item Short-Form General Health Survey questionnaire (62.2 ± 21.5 vs 68.5 ± 16.4, P < 0.05) improved after ESWL. Thus, ESWL is a safe and effective method to treat Chinese patients with pancreatic stones. This procedure can significantly improve the success rate of endotherapy.

[Renal hematomas after extracorporeal shock-wave lithotripsy (ESWL)].

PubMed

Pastor Navarro, Héctor; Carrión López, Pedro; Martínez Ruiz, Jesús; Pastor Guzmán, José Ma; Martínez Martín, Mariano; Virseda Rodríguez, Julio A

2009-03-01

The use of fragmentation due to shock- waves as a treatment of urinary stone was one of the most important therapeutics findings in the history of urology. It's the first election treatment for most of the calculus at renal and urethral location due to the fact that it is a low invasive treatment and it has a few number of complications, but this method also has a few negative side effects, it can caused a more or less important traumatic lesion at the organs which crosses the shock-waves, including the kidney where it can caused a small contusion or renal hematoma with different resolution and treatment. We reviewed 4815 extracorporeal shock-wave lithotripsy that we performed in our department in which we found six cases with subcapsular and perirenal hematoma which we followed up and treated. After the urological complications (pain, obstruction and infection) the renal and perirenal hematic collections are the most frequent adverse effects of shock-waves used in lithotripsy, these are related to the power of energy used and patient age. Between the years 1992-2007 we performed 4.815 extracorporeal shock-wave lithotripsy finding seven cases of severe hematoma, less then 1%. Treatment of these complications is usually not aggressive though sometimes it is necessary to perform surgical drainage and even nephrectomy.

Emergency shock wave lithotripsy for ureteric stones.

PubMed

Dasgupta, Ranan; Hegarty, Nicholas; Thomas, Kay

2009-03-01

Extracorporeal shock wave lithotripsy has been used for over 2 decades, but its application in the acute setting remains under review. With continuing refinements to the technology, it is timely to review its efficacy in the emergency setting. The procedure has an overall low morbidity and is generally well tolerated. Success rates of 70-80% are reported in a number of studies, with relatively low complication rates. Although much attention has been given to the improvements in the outcome of ureteroscopic stone clearance, the benefits of a noninvasive procedure which does not require general anaesthesia may be appealing and indeed preferable for many patients. This should remain a valid alternative treatment option offered to patients, and its provision may be restricted by resource availability rather than clinical evidence. Centres should be identified that can offer an emergency extracorporeal shock wave lithotripsy service and patients informed of outcome data from such centres.

Uncovering the Secret of Shock Wave Lithotripsy

NASA Astrophysics Data System (ADS)

Zhong, P.

Shock wave lithotripsy (SWL) is an engineering innovation that has revolutionized the treatment of kidney stone disease since the early 1980s [1] - [3]. Today, SWL is the first-line therapy for millions of patients worldwide with renal and upper urinary stones [3, 4].

A Case of Acute Pancreatitis developing after Extracorporeal Shock Wave Lithotripsy.

PubMed

Goral, Vedat; Sahin, Erkan; Arslan, Murat

2015-01-01

Extracorporeal shock wave lithotripsy (ESWL) is a standard treatment method used for the treatment of renal calculi and upper ureteral calculi. Acute pancreatitis is a serious condition which develops due to multiple etiologic factors and is characterized by autodigestion of the pancreas. A case of acute pancreatitis which developed following ESWL performed for right renal calculi treatment is presented here. Goral V, Sahin E, Arslan M. A Case of Acute Pancreatitis developing after Extracorporeal Shock Wave Lithotripsy. Euroasian J Hepato-Gastroenterol 2015;5(1):52-54.

Influence of Pelvicaliceal Anatomy on Stone Clearance After Flexible Ureteroscopy and Holmium Laser Lithotripsy for Large Renal Stones.

PubMed

Inoue, Takaaki; Murota, Takashi; Okada, Shinsuke; Hamamoto, Shuzo; Muguruma, Kouei; Kinoshita, Hidefumi; Matsuda, Tadashi

2015-09-01

This study was performed to evaluate the impact of pelvicaliceal anatomy on stone clearance in patients with remnant fragments in the lower pole after flexible ureteroscopy and holmium laser lithotripsy (fURSL) for renal stones >15 mm. This retrospective study included 67 patients with radiopaque residual fragments (>2 mm) in the lower pole after fURSL for large renal stones (>15 mm). The preoperative infundibular length (IL), infundibular width (IW), infundibulopelvic angle (IPA), and caliceal pelvic height (CPH) were measured using intravenous urography. Multivariate analysis was performed to determine whether any of these measurements affected stone clearance. Of the 67 patients, 55 (82.1%) were stone free (SF) 3 months after fURSL. The anatomic factors significantly favorable for an SF status were a short IL, broad IW, wide IPA, and low CPH. On multivariate analysis, the IPA had a significant influence on an SF status after fURSL (p=0.010). An IPA <30° was a negative risk factor (p=0.019). Postoperative complications occurred in nine patients (13.4%), including Clavien grade I complications in two patients (2.9%), grade II in six patients (8.9%), and grade IIIa in one patient (1.8%). Almost all complications were minor. An IPA <30° is the only negative risk factor for stone clearance after fURSL for large renal stones according to our multivariate analysis. Additional studies are required to further evaluate the characteristics of the pelvicaliceal anatomy influencing stone clearance.

Applications of rigid and flexible GRIN-endoscopes

NASA Astrophysics Data System (ADS)

Schenkl, Selma; Ehlers, Alexander; Riemann, Iris; Messerschmidt, Bernhard; Bückle, Rainer; König, Karsten

2007-02-01

Multiphoton autofluorescence imaging became an important technique for minimal invasive examination of cells in biological tissue. Rigid and flexible endoscopes based on gradient index lenses (GRIN-lenses) extend this minimalinvasive technique to deep lying cell layers, inner body and specimens, difficult to access. In the rigid endoscope, a GRIN-lens overcomes the limited depth range, given by the working distance of the microscope objective. The focus of the conventional laser scanning tomography is reproduced tens of millimeters in the specimen under study by the GRIN-lens (diameter 1.8 and 3 μm). We will present images of fluorescent beads, proteins cells and skin tissue, as well as first in vivo measurements on human skin. The autofluorescence signal stems from the endogenous fluorophore elastin and SHG from collagen. The flexible endoscope dispenses completely the need of a microscope next to the specimen of interest. The excitation laser pulses is delivered via a well-characterized photonic crystal fiber and subsequently focused by a newly designed GRIN-lens system. The fluorescence, also transferred by a fiber is detected by a PMT detector. We will show the excellent imaging qualities of a newly developed GRIN-lens system with high-resolution images of proteins, cells and plant tissue and give an out-look on multiphoton endoscopy.

Advanced endoscopic imaging in gastric neoplasia and preneoplasia

PubMed Central

Lee, Jonathan W J; Lim, Lee Guan; Yeoh, Khay Guan

2017-01-01

Conventional white light endoscopy remains the current standard in routine clinical practice for early detection of gastric cancer. However, it may not accurately diagnose preneoplastic gastric lesions. The technological advancements in the field of endoscopic imaging for gastric lesions are fast growing. This article reviews currently available advanced endoscopic imaging modalities, in particular chromoendoscopy, narrow band imaging and confocal laser endomicroscopy, and their corresponding evidence shown to improve diagnosis of preneoplastic gastric lesions. Raman spectrometry and polarimetry are also introduced as promising emerging technologies. PMID:28176895

Novel fiber optic tip designs and devices for laser surgery

NASA Astrophysics Data System (ADS)

Hutchens, Thomas Clifton

Fiber optic delivery of laser energy has been used for years in various types of surgical procedures in the human body. Optical energy provides several benefits over electrical or mechanical surgery, including the ability to selectively target specific tissue types while preserving others. Specialty fiber optic tips have also been introduced to further customize delivery of laser energy to the tissue. Recent evolution in lasers and miniaturization has opened up opportunities for many novel surgical techniques. Currently, ophthalmic surgeons use relatively invasive mechanical tools to dissect retinal deposits which occur in proliferative diabetic retinopathy. By using the tight focusing properties of microspheres combined with the short optical penetration depth of the Erbium:YAG laser and mid-IR fiber delivery, a precise laser scalpel can be constructed as an alternative, less invasive and more precise approach to this surgery. Chains of microspheres may allow for a self limiting ablation depth of approximately 10 microm based on the defocusing of paraxial rays. The microsphere laser scalpel may also be integrated with other surgical instruments to reduce the total number of handpieces for the surgeon. In current clinical laser lithotripsy procedures, poor input coupling of the Holmium:YAG laser energy frequently damages and requires discarding of the optical fiber. However, recent stone ablation studies with the Thulium fiber laser have provided comparable results to the Ho:YAG laser. The improved spatial beam profile of the Thulium fiber laser can also be efficiently coupled into a fiber approximately one third the diameter and reduces the risk of damaging the fiber input. For this reason, the trunk optical fiber minus the distal fiber tip can be preserved between procedures. The distal fiber tip, which degrades during stone ablation, could be made detachable and disposable. A novel, low-profile, twist-locking, detachable distal fiber tip interface was designed

Stone/tissue differentiation during intracorporeal lithotripsy using diffuse white light reflectance spectroscopy: In vitro and clinical measurements.

PubMed

Lange, Birgit; Jocham, Dieter; Brinkmann, Ralf; Cordes, Jens

2014-10-01

Holmium laser lithotripsy is the 'gold standard' for intracorporeal fragmentation of stones. However, there is a risk of damaging and perforating the ureter wall when the laser is accidentally fired while the fiber is in contact with tissue. The aim of this study was to evaluate if white illumination light, diffusely reflected back into the treatment fiber and spectrally analyzed, can be used for differentiating between stone and tissue. Firstly, in vitro reflectance spectra (Xenon light source, wavelength range λ = 350-850 nm) of 38 human kidney stones, porcine renal calix and ureter tissue were collected. Secondly, in an in vivo study with 8 patients, 72 ureter and 49 stone reflectance signals were recorded during endourological interventions. The spectra were analyzed to discriminate between stone and tissue by the absence or presence of minima due to hemoglobin absorption at λ1  = 542nm and λ3  = 576nm. In vitro, all stone and tissue signals could correctly be identified by calculating the ratio R = I (λ1  = 542 nm)/I (λ2  = 475 nm): Because of the hemoglobin absorption at λ1 , R is smaller for tissue than for calculi. In vivo, only 75% tissue spots could correctly be identified utilizing this method. Using the more sophisticated evaluation of looking for minima in the diffuse reflectance spectra at λ1  = 542 nm and λ3  = 576 nm, 62 out of 64 tissue spots were correctly identified (sensitivity 96.9%). This was also the case for 39 out of 43 stone spots. Taking into account the number of measured spectra, a tissue detection probability of 91% and a stone detection probability of 77% was achieved (significance level 5%). White light diffusely reflected off the treatment zone into the fiber can be used to strongly improve the safety of Holmium laser lithotripsy by implementing an automatic feedback control algorithm that averts mispositioning the fiber. © 2014 Wiley Periodicals, Inc.

Endoscopic ultrasonography in the management of esophageal cancer

NASA Astrophysics Data System (ADS)

Trowers, Eugene A.

2000-05-01

Precise tumor-staging is critical in the management of early esophageal caner. Endoscopic ultrasound (EUS) allows the endoscopist a view beyond the esophageal wall which opens the door to a variety of new gastroenterologic techniques. Endoscopic mucosal resection, laser photoablation and photodynamic therapy may be successfully employed in early esophageal cancer management. Combination radiation therapy and chemotherapy have shown better responses in advanced cancer. Expandable metallic stents may also provide palliation with inoperable esophageal cancer. The efficacy of EUS in the management of esophageal cancer is critically reviewed.

Possibilities of lasers within NOTES.

PubMed

Stepp, Herbert; Sroka, Ronald

2010-10-01

Lasers possess unique properties that render them versatile light sources particularly for NOTES. Depending on the laser light sources used, diagnostic as well as therapeutic purposes can be achieved. The diagnostic potential offered by innovative concepts such as new types of ultra-thin endoscopes and optical probes supports the physician with optical information of ultra-high resolution, tissue discrimination and manifold types of fluorescence detection. In addition, the potential 3-D capability promises enhanced recognition of tissue type and pathological status. These diagnostic techniques might enable or at least contribute to accurate and safe procedures within the spatial restrictions inherent with NOTES. The therapeutic potential ranges from induction of phototoxic effects over tissue welding, coagulation and tissue cutting to stone fragmentation. As proven in many therapeutic laser endoscopic treatment concepts, laser surgery is potentially bloodless and transmits the energy without mechanical forces. Specialized NOTES endoscopes will likely incorporate suitable probes for improving diagnostic procedures, laser fibres with advantageous light delivery possibility or innovative laser beam manipulation systems. NOTES training centres may support the propagation of the complex handling and the safety aspects for clinical use to the benefit of the patient.

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.

A novel technique using high energy synchronous double-wave laser in endoscopic submucosal dissection of patients with superficial esophageal neoplasm.

PubMed

Yao, Jun; Li, Jun; Wang, Peng; Liu, Feng; Li, Zhaoshen

2018-06-08

BACKGROUND : Endoscopic submucosal dissection (ESD) has been widely used to treat superficial esophageal neoplasms (SENs). Intraoperative bleeding is one of the main concerns that makes ESD in the esophagus more difficult and time consuming with higher complication rates. We introduced a novel laser endoknife system that enabled better intraoperative hemostasis, and preliminarily investigated its feasibility in ESD for patients with SENs.  17 consecutive patients with SENs were prospectively enrolled. The laser endoknife system was used in marking and submucosal dissection. Data on therapeutic outcomes were collected and analyzed.  The median diameter of the lesions was 2.5 cm and of the resected specimens was 3.0 cm. The median procedure time was 48 minutes. Histologic evaluation revealed 15 high grade intraepithelial neoplasias and two squamous cell carcinomas. No intraoperative bleeding occurred during laser cutting and no significant complications occurred postoperatively. Curative R0 resection was achieved in all patients.  Our new laser endoknife system was feasible in the submucosal dissection of SENs and showed great prospects for future application. © Georg Thieme Verlag KG Stuttgart · New York.

Urinary extracorporeal shock wave lithotripsy: equipment, techniques, and overview.

PubMed

Pfister, R C; Papanicolaou, N; Yoder, I C

1988-01-01

Second generation urinary lithotriptors are characterized by extensive technical alterations and significant equipment improvement in the functional, logistical, and medical aspects of shock wave lithotripsy (SWL). These newer devices feature a water bath-free environment, a reduced anesthesia requirement, improved imaging, functional uses in addition to lithotripsy, or combinations thereof. Shock wave generation by spark gap, electromagnetic, piezoelectric and microexplosive techniques are related to their peak energy, frequency, and total energy capabilities which impacts on both anesthesia needs and the length and number of treatment sessions required to pulverize calculi. A master table summarizes the types of SW energy, coupling, imaging systems, patient transport, functional features, cost, and treatment effectiveness of 12 worldwide lithotriptors in various stages of investigative and clinical trials as monitored by the Food and Drug Administration (FDA) of America.

High-speed photography during laser-based gall bladder stone lithotripsy

NASA Astrophysics Data System (ADS)

Kokaj, Jahja O.

2001-04-01

Shadowgraphy of gall bladder stone, which is held by a basket and immersed in a civete is performed. The exposure time is determined by the time of a N-Dye laser pulse used as a lightening source for photography. The shadowgram is projected in the objective of a camera which is connected to a microscope. The light coming from the laser, illuminates the civete collecting optical information of the stone and physical phenomena appearing above the stone. On top of the stone a tip of optical fiber is fixed, which is used for transmitting Ho:Yag laser power to the stone. Using a computer and time delay the laser pulses used for destruction and illumination are synchronized. Since the N-Dye laser pulse is pico-second range and the Ho:Yag laser pulse is in the range of micro-second, many image frames are obtained within the time of one pulse applied during the destruction. It is known that in the process of stone destruction several phenomena like plume, plasma, shock wave and bubble formation take place. However, the physical mechanism of the stone destruction is not yet completely understood. From the obtained results the above phenomena are studied which gives new information and clue for understanding some of the mentioned phenomena. The laser power which is guided by an optical fiber into the gall bladder or kidney of the human body can damage the living tissue and cause some serious health problems. For this reason the fiber needs to be oriented properly during the action of the laser power.

Our experience with transcanalicular laser-assisted endoscopic dacryocystorhinostomy (TCLADCR) in patients of chronic dacryocystitis with deviated nasal septum.

PubMed

Goel, Ruchi; Nagpal, Smriti; Kumar, Sushil; Kamal, Saurabh; Dangda, Sonal; Bodh, Sonam Angmo

2015-12-01

The purpose of this study is to study the operative difficulties and success rate of transcanalicular laser-assisted endoscopic dacryocystorhinostomy in patients of chronic dacryocystitis with deviated nasal septum (DNS). A prospective interventional clinical study of 36 consecutive patients suffering from chronic dacryocystitis with nasolacrimal duct obstruction with DNS undergoing primary TCLADCR from March to June 2011 was carried out. Diode laser was used to create a 16-mm(2) ostium which was enlarged to 64 mm(2) using Blakesley's forceps. Success was defined as anatomical patency and absence of symptoms at 12 months of follow-up. Out of the 36 patients, 25 were females with ages 20-72 years, and 19 were left sided. There were 12 high, 12 mid and 12 basal DNS towards the side of surgery, mild to moderate in severity. Intraoperatively there was difficulty in visualising the aiming beam in the nose, tedious manipulation of endoscope and excessive bleeding in 3 patients. Increased bleeding and failures were significantly higher in high DNS (Fisher exact test-2 tailed: 0.0045). The procedure was successful in 94.4 % cases with average ostium size of 21.94 mm(2) at 12 months and no statistically significant difference in success rates between mild and moderate DNS (Fisher exact test-2 tailed: 1.000). Also there was no difference in the complication rate between mild and moderate DNS (Fisher exact test-2 tailed: 0.0841). TCLADCR is an effective procedure in patients with mild to moderate mid and basal DNS and obviates the need for multiple procedures and a cutaneous scar.

Electromagnetic shock-wave lithotripsy of gallbladder calculi. Multicentered preliminary report on experience with 276 patients.

PubMed

Classen, M; Cremer, M; Faustini, S; Meiser, G; zum Büschenfelde, M; Neuhaus, H; Ott, R; Pizzi, P; Salvini, A; Staritz, M

1990-08-01

The Lithostar Working Group reports on the first 276 patients who underwent lithotripsy of biliary calculi by means of an electromagnetic Lithotriptor (Lithostar Plus from Siemens). Some 66% (183/276) and 27% (75/276) of the patients had solitary and two or three stones, respectively while 7% (18/276) had more than three gallbladder calculi. Calcified calculi were found in 11% of the patients. On an average the patients were treated in 1.6 (range 1.4-2.15) sessions; with the exception of one user the maximal energy (setting 9) was applied. The upper limit of shock waves per session was 1500-6000 (x = 2189 +/- 1058). 17% and 48% of the patients were free from calculi after 3 and 6 months, respectively. During the follow-up period 14% of the patients complained of severe biliary pain and 1.5% suffered from pancreatitis, which was controlled by conservative treatment. In three out of five patients with a transitory cholestatic jaundice endoscopic papillotomy was necessary. Four patients underwent an elective cholecystectomy. Considering the selection of the patients, the results obtained are comparable with those found in other studies.

Ultrahigh-resolution endoscopic optical coherence tomography

NASA Astrophysics Data System (ADS)

Chen, Yu; Herz, Paul R.; Hsiung, Pei-Lin; Aguirre, Aaron D.; Mashimo, Hiroshi; Desai, Saleem; Pedrosa, Macos; Koski, Amanda; Schmitt, Joseph M.; Fujimoto, James G.

2005-01-01

Early detection of gastrointestinal cancer is essential for the patient treatment and medical care. Endoscopically guided biopsy is currently the gold standard for the diagnosis of early esophageal cancer, but can suffer from high false negative rates due to sampling errors. Optical coherence tomography (OCT) is an emerging medical imaging technology which can generate high resolution, cross-sectional images of tissue in situ and in real time, without the removal of tissue specimen. Although endoscopic OCT has been used successfully to identify certain pathologies in the gastrointestinal tract, the resolution of current endoscopic OCT systems has been limited to 10 - 15 m for clinical procedures. In this study, in vivo imaging of the gastrointestinal tract is demonstrated at a three-fold higher resolution (< 5 m), using a portable, broadband, Cr4+:Forsterite laser as the optical light source. Images acquired from the esophagus, gastro-esophageal junction and colon on animal model display tissue microstructures and architectural details at high resolution, and the features observed in the OCT images are well-matched with histology. The clinical feasibility study is conducted through delivering OCT imaging catheter using standard endoscope. OCT images of normal esophagus, Barrett's esophagus, and esophageal cancers are demonstrated with distinct features. The ability of high resolution endoscopic OCT to image tissue morphology at an unprecedented resolution in vivo would facilitate the development of OCT as a potential imaging modality for early detection of neoplastic changes.

Massive Pulmonary Calculi Embolism: A Novel Complication of Pneumatic Lithotripsy: A Case Report.

PubMed

Zhang, Lin; Zhou, Yiwu

2015-07-01

Pneumatic lithotripsy is a minimally invasive technique mainly for the treatment of urinary staghorn stones. Previous literatures have reported some therapeutic complications during or after this procedure, but calculi embolism has not been mentioned before.We report here a fatal case of calculi-induced pulmonary embolism in an adult woman who underwent pneumatic lithotripsy. An autopsy did not reveal any evidence of pulmonary embolism. However, light microscopy revealed noticeable presence of calculi in pulmonary arterioles and capillaries, as evidenced by environmental scanning electron microscope and energy dispersive X-ray analysis. The primary determinants of calculi embolism include intrarenal pressure, and volume and viscosity of the calculi fragments formation. Vascular intravasation of smashed calculi might increase pulmonary vascular resistance and hypoxemia and decrease cardiac output.This case report intends to provide information for clinicians to consider the probability of intraoperative calculi embolism during lithotripsies when patients develop typical symptoms of acute pulmonary embolism.

Simple fibre based dispersion management for two-photon excited fluorescence imaging through an endoscope

NASA Astrophysics Data System (ADS)

Dimopoulos, Konstantinos; Marti, Dominik; Andersen, Peter E.

2018-02-01

We want to implement two-photon excitation fluorescence microscopy (TPEFM) into endoscopes, since TPEFM can provide relevant biomarkers for cancer staging and grading in hollow organs, endoscopically accessible through natural orifices. However, many obstacles must be overcome, among others the delivery of short laser pulses to the distal end of the endoscope. To this avail, we present imaging results using an all-fibre dispersion management scheme in a TPEFM setup. The scheme has been conceived by Jespersen et al. in 20101 and relies on the combination of a single mode fibre with normal and a higher order mode fibre with anomalous dispersion properties, fused in series using a long period grating. We show that using this fibre assembly, a simple and robust pulsed laser delivery system without any free-space optics, which is thus suitable for clinical use, can be realised.

Is pre-shock wave lithotripsy stenting necessary for ureteral stones with moderate or severe hydronephrosis?

PubMed

El-Assmy, Ahmed; El-Nahas, Ahmed R; Sheir, Khaled Z

2006-11-01

We performed a prospective, randomized clinical trial to evaluate the outcome of ureteral stents for solitary ureteral stones 2 cm or less in moderately or severely obstructed systems using shock wave lithotripsy. Between 2001 and 2004, 186 patients who met study criteria were randomized into 2 groups. Group 1 received a pre-shock wave lithotripsy 6Fr Double-J stent and group 2 had no stent. Patients were treated with a Dornier MFL 5000 lithotripter. Results were compared in terms of clearance rates, number of shock waves and sessions, irritative voiding symptoms, incidence of complications and secondary interventions. Failure was defined as the need for additional procedure(s) for stone extraction. Overall 164 patients (88.2%) became stone-free after shock wave lithotripsy. Complete stone fragmentation was achieved after 1 to 3 and more than 3 session in 108 (58.1%), 30 (16.1%), 13 (7%) and 14 patients (7.5%), respectively. Ureteral stent insertion did not affect the stone-free rate, which was 84.9% and 91.4% in groups 1 and 2, respectively (p = 0.25). There was no statistical difference in the re-treatment rate, flank pain or temperature in the 2 groups. However, all patients in the stented group significantly complained of side effects attributable to the stent, including dysuria, suprapubic pain, hematuria, pyuria and positive urinary culture. Pretreatment stenting provides no advantage over in situ shock wave lithotripsy for significantly obstructing ureteral calculi. Shock wave lithotripsy is reasonable initial therapy for ureteral stones 2 cm or less that cause moderate or severe hydronephrosis.

Single-session ureteroscopic pneumatic lithotripsy for the management of bilateral ureteric stones.

PubMed

Isen, Kenan

2012-01-01

In nowadays there is no consensus on single-session ureteroscopic lithotripsy (URSL) for the management of bilateral ureteric stones. The aim of this study was to evaluate efficacy and safety of single-session URSL in patients with bilateral ureteric stones. 41 patients who have undergone bilateral single-session URSL were evaluted in this study. A 8/9.8 Fr Wolf semi-rigid ureteroscope was used for the procedures, and the stones were fragmented with pneumatic lithotripter. A high stone-free rate was achieved (90.2%) after single endoscopic procedure with a retreatment rate of 9.8%. The procedure was most successful for distal ureteric stones with a 96.2% stone-free rate followed by middle ureteric stones with a 81.8% stone-free rate while the least success was achieved for proximal ureteric stones with a 77.7% stone-free rate (p < 0.05). A greater stone-free rate was obtained in those with stones less than 10 mm (93.7%) than in those with stones larger than 10 mm (77.7%) (p < 0.05). Ureteral perforation occurred in only one patient (2.4%). No long-term complication was observed in any patient. Bilateral single-session URSL can be performed effectively and safely with a low complication rate in patients with bilateral ureteric stones. It can reduce the need of anaesthetics and hospital stay.

Optical transfection using an endoscope-like system.

PubMed

Ma, Nan; Gunn-Moore, Frank; Dholakia, Kishan

2011-02-01

Optical transfection is a powerful method for targeted delivery of therapeutic agents to biological cells. A tightly focused pulsed laser beam may transiently change the permeability of a cell membrane to facilitate the delivery of foreign genetic material into cells. We report the first realization of an endoscope-like integrated system for optical transfection. An imaging fiber (coherent optical fiber bundle) with ∼ 6000 cores (pixels) embedded in a fiber cladding of ∼ 300 μm in diameter, produces an image circle (area) of ∼ 270 μm diam. This imaging fiber, with an ordered axicon lens array chemically etched at its exit face, is used for the delivery of a femtosecond laser to the cell membrane for optical transfection along with subcellular resolution imaging. A microcapillary-based microfluidic system for localized drug delivery was also combined in this miniature, flexible system. Using this novel system, a plasmid transfection efficiency up to ∼ 72% was obtained for CHO-K1 cells. This endoscope-like system opens a range of exciting applications, in particular, in the targeted in vivo optical microsurgery area.

Endoscopic laser Doppler flowmetry in the experiment and in the bleeding gastric and duodenal ulcer clinic

NASA Astrophysics Data System (ADS)

Kapralov, S. V.; Shapkin, Y. G.; Lychagov, V. V.; Tuchin, V. V.

2007-05-01

One of the most complex problems of emergency surgery is the choice of surgical tactics to deal with bleeding peptic ulcer. Endoscopic hemostasis is prescribed to patients with continuing bleedings and prerelapse syndrome. But till nowdays the objective verification of the prerelapse condition had not been worked out. What is more there are no objective criteria to judge the effectiveness of the carried endohemostasis. The aim of the study was to work out a new objective diagnostic method of pre-recurrence syndrome that can be able to make prognosis for possible gastroduodenal ulcer bleeding recurrence more precise. Laser Doppler flowmetry was the method of studies the regional perfusion. The device used in this work was made at the Optics and Biophysics Department of Saratov State University.

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.

Case series: Endoscopic management of fourth branchial arch anomalies.

PubMed

Watson, G J; Nichani, J R; Rothera, M P; Bruce, I A

2013-05-01

Fourth branchial arch anomalies represent <1% of all branchial anomalies and present as recurrent neck infections or suppurative thyroiditis. Traditionally, management has consisted of treatment of the acute infection followed by hemithyroidectomy, surgical excision of the tract and obliteration of the opening in the pyriform fossa. Recently, it has been suggested that endoscopic obliteration of the sinus tract alone using laser, chemo or electrocautery is a viable alternative to open surgery. To determine the results of endoscopic obliteration of fourth branchial arch fistulae in children in our institute. Retrospective case note review of all children undergoing endoscopic treatment of fourth branchial arch anomalies in the last 7 years at the Royal Manchester Children's Hospital. Patient demographics, presenting symptoms, investigations and surgical technique were analysed. The primary and secondary outcome measures were resolution of recurrent infections and incidence of surgical complications, respectively. In total 5 cases were identified (4 females and 1 male) aged between 3 and 12 years. All presented with recurrent left sided neck abscesses. All children underwent a diagnostic laryngo-tracheo-bronchoscopy which identified a sinus in the apex of the left pyriform fossa. This was obliterated using electrocautery in 1 patient, CO₂ laser/Silver Nitrate chemocautery in 2 patients and Silver Nitrate chemocautery in a further 2 patients. There were no complications and no recurrences over a mean follow-up period of 25 months (range 11-41 months). Endoscopic obliteration of pyriform fossa sinus is a safe method for treating fourth branchial arch anomalies with no recurrence. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Feasibility of endoscopic laser speckle imaging modality in the evaluation of auditory disorder: study in bone-tissue phantom

NASA Astrophysics Data System (ADS)

Yu, Sungkon; Jang, Seulki; Lee, Sangyeob; Park, Jihoon; Ha, Myungjin; Radfar, Edalat; Jung, Byungjo

2016-03-01

This study investigates the feasibility of an endoscopic laser speckle imaging modality (ELSIM) in the measurement of perfusion of flowing fluid in optical bone tissue phantom(OBTP). Many studies suggested that the change of cochlear blood flow was correlated with auditory disorder. Cochlear microcirculation occurs under the 200μm thickness bone which is the part of the internal structure of the temporal bone. Concern has been raised regarding of getting correct optical signal from hard tissue. In order to determine the possibility of the measurement of cochlear blood flow under bone tissue using the ELSIM, optical tissue phantom (OTP) mimicking optical properties of temporal bone was applied.

Shear Wave Elastographic Alterations in the Kidney After Extracorporeal Shock Wave Lithotripsy.

PubMed

Turkay, Rustu; Inci, Ercan; Bas, Derya; Atar, Arda

2018-03-01

Extracorporeal shock wave lithotripsy (ESWL) is a method used frequently for the treatment of renal stone disease. Although its safety is proven, there are still concerns about its unwanted effects on kidneys. In this prospective study, we aimed to evaluate renal tissue alterations with shear wave elastography (SWE) after ESWL. We also studied the correlation between SWE and resistive index (RI) changes. The study included 59 patients who underwent ESWL treatment for renal stone disease. We performed SWE and color Doppler ultrasonography to calculate SWE and RI values before, 1 hour after, and 1 week after lithotripsy treatment. A binary comparison was performed by the Bonferroni test. The correlation between SWE and RI values was evaluated by a Pearson correlation analysis. The patients included 26 women (44.1%) and 33 men (55.9%). Their ages ranged from 20 to 65 years (mean ± SD, 45.0 ± 1.1 years). Stone diameters ranged from 7 to 19 mm (mean, 13.0 ± 0.5 mm). There was a significant difference in SWE values before and 1 hour after lithotripsy treatment (P = .001; P < .01). In the follow-up measurement 1 week after treatment, this difference disappeared (P > .99; P > .05). Resistive index values increased significantly 1 hour after lithotripsy treatment and returned to prelithotripsy values 1 week after treatment. In the correlation analysis, SWE and RI values were not correlated. Measurements of alterations in SWE values after ESWL can provide useful information about renal tissue injury. © 2017 by the American Institute of Ultrasound in Medicine.

[Color processing of ultrasonographic images in extracorporeal lithotripsy].

PubMed

Lardennois, B; Ziade, A; Walter, K

1991-02-01

A number of technical difficulties are encountered in the ultrasonographic detection of renal stones which unfortunately limit its performance. The margin of error of firing in extracorporeal shock-wave lithotripsy (ESWL) must be reduced to a minimum. The role of the ultrasonographic monitoring during lithotripsy is also essential: continuous control of the focussing of the short-wave beamand assessment if the quality of fragmentation. The authors propose to improve ultrasonographic imaging in ESWL by means of intraoperative colour processing of the stone. Each shot must be directed to its target with an economy of vision avoiding excessive fatigue. The principle of the technique consists of digitalization of the ultrasound video images using a Macintosh Mac 2 computer. The Graphis Paint II program is interfaced directly with the Quick Capture card and recovers the images on its work surface in real time. The program is then able to attribute to each of these 256 shades of grey any one of the 16.6 million colours of the Macintosh universe with specific intensity and saturation. During fragmentation, using the principle of a palette, the stone changes colour from green to red indicating complete fragmentation. A Color Space card converts the digital image obtained into a video analogue source which is visualized on the monitor. It can be superimposed and/or juxtaposed with the source image by means of a multi-standard mixing table. Colour processing of ultrasonographic images in extracoporeal shockwave lithotripsy allows better visualization of the stones and better follow-up of fragmentation and allows the shockwave treatment to be stopped earlier. It increases the stone-free performance at 6 months. This configuration will eventually be able to integrate into the ultrasound apparatus itself.

Miniature ball-tip optical fibers for use in thulium fiber laser ablation of kidney stones

NASA Astrophysics Data System (ADS)

Wilson, Christopher R.; Hardy, Luke A.; Kennedy, Joshua D.; Irby, Pierce B.; Fried, Nathaniel M.

2016-01-01

Optical fibers, consisting of 240-μm-core trunk fibers with rounded, 450-μm-diameter ball tips, are currently used during Holmium:YAG laser lithotripsy to reduce mechanical damage to the inner lining of the ureteroscope working channel during fiber insertion and prolong ureteroscope lifetime. Similarly, this study tests a smaller, 100-μm-core fiber with 300-μm-diameter ball tip during thulium fiber laser (TFL) lithotripsy. TFL was operated at a wavelength of 1908 nm, with 35-mJ pulse energy, 500-μs pulse duration, and 300-Hz pulse rate. Calcium oxalate/phosphate stone samples were weighed, laser procedure times were measured, and ablation rates were calculated for ball tip fibers, with comparison to bare tip fibers. Photographs of ball tips were taken before and after each procedure to track ball tip degradation and determine number of procedures completed before need for replacement. A high speed camera also recorded the cavitation bubble dynamics during TFL lithotripsy. Additionally, saline irrigation rates and ureteroscope deflection were measured with and without the presence of TFL fiber. 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 greater than four stone procedures before failure, defined by rapid decline in stone ablation rates. Mechanical damage at the front surface of the ball tip was the limiting factor in fiber lifetime. The small fiber diameter did not significantly 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 into the ureter without risk of instrument damage or tissue perforation, and without compromising stone ablation efficiency during TFL lithotripsy.

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.

Ureteroscopic Lithotripsy

PubMed Central

Bagley, Demetrius H.

1997-01-01

There is a wide array of endoscopic lithotriptors presently available. Each of these has its own advantages and disadvantages. No single lithotriptor is suitable for all applications and none can meet the goal of fragmenting all calculi while remaining harmless to tissue. PMID:18493444

Use of the holmium:YAG laser in urology

NASA Astrophysics Data System (ADS)

Mattioli, Stefano

1997-12-01

The Holmium-YAG is a versatile laser with multiple soft- tissue applications including tissue incision and vaporization, and pulsed-laser applications such as lithotripsy. At 2140 nanometers, the wavelength is highly absorbed by tissue water. Further, like CO2 laser, the Holmium produces immediate tissue vaporization while minimizing deep thermal damage to surrounding tissues. It is an excellent instrument for endopyelotomy, internal urethrotomy, bladder neck incisions and it can be used to resect the prostate. The Holmium creates an acute TUR defect which gives immediate results like the TURP. More than 50 patients were treated from Jan. 1996 to Jan. 1997 for obstructive symptoms due to benign prostatic hyperplasia, bladder neck stricture, urethral stenosis, and superficial bladder tumors.

Treatment of Renal Calculi with Extracorporeal Shock Wave Lithotripsy

PubMed Central

Eberwein, P. M.; Denstedt, J. D.

1992-01-01

In 12 years, extracorporeal shock wave lithotripsy has replaced other treatment techniques for most surgical calculi in the upper urinary tract. Worldwide clinical series have documented its efficacy. Technological advances and modifications have significantly expanded the clinical applications of this technique. Imagesp1673-aFigure 3 PMID:21221368

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

Systems workplace for endoscopic surgery.

PubMed

Irion, K M; Novak, P

2000-01-01

With the advent of minimally invasive surgery (MIS) a decade ago, the requirements for operating rooms (OR) and their equipment have been increased. Compared with conventional open surgery, the new endoscopic techniques require additional tools. Television systems, for video-assisted image acquisition and visualisation, including cameras, monitors and light systems, as well as insufflators, pumps, high-frequency units, lasers and motorised therapy units, are nowadays usually made available on carts during endoscopic surgery. In conjunction with a set of endoscopic instruments, these high-tech units allow new operating techniques to be performed. The benefit for patients has become clear in recent years; however, the technical complexity of OR has also increased considerably. To minimise this problem for the OR personnel, the MIS concept 'OR1' (Operating Room 1) was developed and implemented. OR1 is a fully functional and integrated multi-speciality surgical suite for MIS. The centrepieces of the OR1 are the Storz Communication Bus (SCB) and the advanced image and data archiving system (Aida) from Karl Storz, Tuttlingen, Germany. Both components allow monitoring, access and networking of the MIS equipment and other OR facilities, as well as the acquisition, storage and display of image, patient and equipment data during the endoscopic procedure. A central user interface allows efficient, simplified operation and online clinical images. Due to the system integration, the handling of complex equipment is considerably simplified, logistical procedures in the OR are improved, procedure times are shorter and, particularly noteworthy, operative risk can be reduced through simplified device operation.

Endoscopic treatment of chronic radiation proctopathy.

PubMed

Wilson, Sydney A; Rex, Douglas K

2006-09-01

Chronic radiation proctopathy is a complication of pelvic radiation therapy. The acute phase of radiation injury to the rectum occurs during or up to 3 months following radiation. Acute radiation injury can continue into a chronic phase or chronic radiation proctopathy may develop after a latent period of several months or years. Symptoms associated with the condition include diarrhea, rectal pain, bleeding, tenesmus, and stricture formation. Of the various symptoms, only bleeding from radiation-induced telangiectasias is amenable to endoscopic therapy. This paper summarizes the findings of experts in the field on endoscopic treatment of bleeding from chronic radiation proctopathy. Medical management is generally ineffective in controlling bleeding from chronic radiation proctopathy. Surgical intervention has a high incidence of morbidity. Promising advances have been made in endoscopic therapy, including formalin, neodymium/yttrium aluminum garnet, argon and potassium titanyl phosphate laser treatments, as well as argon plasma coagulation. Argon plasma coagulation presents an effective, efficient, inexpensive and reasonably safe noncontact method for destruction of radiation telangiectasias. Based on currently available data and trends, argon plasma coagulation is the favored treatment for bleeding from chronic radiation proctopathy.

History of lasers.

PubMed

Gross, Andreas J; Herrmann, Thomas R W

2007-06-01

The developments of laser technology from the cradle of modern physics in 1900 by Planck to its latest medical boundaries is an exciting example of how basic physics finds its way into clinical practice. This article merits the protagonists and their contribution to the steps in this development. The competition between the different research groups finally led to the award of the Nobel Prize to Townes, Basov and Prokhorov in 1964 for the scientific basis on quantum electronics, which led to the construction of oscillators and amplifiers based on the laser-maser principle. Forty-three years after Einstein's first theories Maiman introduced the first ruby laser for commercial use. This marked the key step for the laser application and pioneered fruitful cooperations between basic and clinical science. The pioneers of lasers in clinical urology were Parsons in 1966 with studies in canine bladders and Mulvany 1968 with experiments in calculi fragmentation. The central technological component for the triumphal procession of lasers in urology is the endoscope. Therefore lasers are currently widely used, being the tool of choice in some areas, such as endoscopical lithotriptic stone treatment or endoluminal organ-preserving tumor ablation. Furthermore they show promising treatment alternatives for the treatment of benign prostate hyperplasia.

Electromagnetic and Electrohydraulic Shock Wave Lithotripsy-Induced Urothelial Damage: Is There a Difference?

PubMed

Mustafa, Mahmoud; Aburas, Honood; Helo, Fatima M; Qarawi, Lailah

2017-02-01

To evaluate and compare the acute effect of electromagnetic and electrohydraulic extracorporeal shockwave lithotripsy (SWL) on the urothelial layers of kidney and ureter. Fifty patients, 29 males (58%) and 21 females (42%), with an average age of 51.68 years (range: 37-70) who underwent SWL application in two different centers were included. Twenty-eight patients (56%) were treated with electrohydraulic and 22 (44%) were treated with electromagnetic lithotripsy. Urinary cytologic examinations were done immediately before and after SWL therapy and 10 days later. The average numbers of epithelial cells, red blood cells (RBC), and myocytes were counted under 40 × magnification. There were significant differences in the number of epithelial cells and RBC before and after immediate application of SWL: 1.66 and 14.9 cells/field, (p = 0.001), 5.44 and 113.45 cells/field, respectively (p = 0.001). The number of RBC was significantly higher in patients treated with electromagnetic lithotripsy than those treated with electrohydraulic: 141.9 and 93.4 cells/field, respectively (p = 0.02). No myocyte or basement membrane elements were detected in any of the cytologic examinations. Cytologic examinations done after 10 days of SWL therapy revealed recovery of all abnormal cytologic findings. The acute increments in the number of epithelial cells and RBC after SWL were statistically significant but it was not permanent. SWL-induced urinary urothelial lesion is limited to the mucosal layer and there was no evidence of damage to the basal membrane or muscle layer. Electromagnetic lithotripsy caused high numbers of RBC than the electrohydraulic device on the postimmediate urine cytologic examination.

Complete prostatic ablation using a two-stage laser

NASA Astrophysics Data System (ADS)

Sayer, Jeanie; Cromeens, Douglas M.; Price, Roger E.; Johnson, Douglas E.

1993-05-01

Laser photoirradiation has been delivered endoscopically for the treatment of both benign prostatic hyperplasia and early localized prostatic carcinoma. In treating carcinoma, aggressive transurethral resection of the prostate has been followed with laser irradiation to the remnants of malignant capsular disease. No attempt has been made heretofore to completely destroy the glandular prostate using laser irradiation alone. We performed a two-stage endoscopic laser prostatectomy in 6 adult mongrel dogs in an attempt to completely destroy the glandular prostate. Although no complications developed, histologic evaluation of the prostate revealed viable glandular elements in the midst of necrosis and atrophy. We conclude that in order to accomplish total ablation of the glandular prostate using laser photoirradiation, more precise thermal telemetry is needed.

Chronic radiation proctopathy: A practical review of endoscopic treatment.

PubMed

Lenz, Luciano; Rohr, Rachel; Nakao, Frank; Libera, Ermelindo; Ferrari, Angelo

2016-02-27

Chronic radiation proctopathy (CRP) is a troublesome complication of pelvic radiotherapy. The most common presentation is rectal bleeding. CRP symptoms interfere with daily activities and decrease quality of life. Rectal bleeding management in patients with CRP represents a conundrum for practitioners. Medical therapy is ineffective in general and surgical approach has a high morbid-mortality. Endoscopy has a role in the diagnosis, staging and treatment of this disease. Currently available endoscopic modalities are formalin, potassium titanyl phosphate laser, neodymium:yttrium-aluminum-garnet laser, argon laser, bipolar electrocoagulation (BiCAP), heater probe, band ligation, cryotherapy, radiofrequency ablation and argon plasma coagulation (APC). Among these options, APC is the most promising.

Threshold Damage of In vivo Porcine Skin at 2000 nm Laser Irradiation

DTIC Science & Technology

2006-01-01

surgery. J Clin Laser Med Surg 1992; 10:211-216. 8. Shapshay SM, Rebeiz EE, Pankratov MM. Holmium: Yttrium Aluminium Garnet laser-assisted endoscopic...laser-assisted endoscopic sinus surgery: laboratory experience. Laryngoscope 1991 ; 101:142-149. 10. Min K, Leu H, Zweifel K. Quantitative determination...JTF. Choice of clip levels for beam width measurements using knife-edge techniques. IEEE J. Quantum Electron. 1991 ; 27:1098-1104 19. Finney DJ

High-quality endoscope reprocessing decreases endoscope contamination.

PubMed

Decristoforo, P; Kaltseis, J; Fritz, A; Edlinger, M; Posch, W; Wilflingseder, D; Lass-Flörl, C; Orth-Höller, D

2018-02-24

Several outbreaks of severe infections due to contamination of gastrointestinal (GI) endoscopes, mainly duodenoscopes, have been described. The rate of microbial endoscope contamination varies dramatically in literature. The aim of this multicentre prospective study was to evaluate the hygiene quality of endoscopes and automated endoscope reprocessors (AERs) in Tyrol/Austria. In 2015 and 2016, a total of 463 GI endoscopes and 105 AERs from 29 endoscopy centres were analysed by a routine (R) and a combined routine and advanced (CRA) sampling procedure and investigated for microbial contamination by culture-based and molecular-based analyses. The contamination rate of GI endoscopes was 1.3%-4.6% according to the national guideline, suggesting that 1.3-4.6 patients out of 100 could have had contacts with hygiene-relevant microorganisms through an endoscopic intervention. Comparison of R and CRA sampling showed 1.8% of R versus 4.6% of CRA failing the acceptance criteria in phase I and 1.3% of R versus 3.0% of CRA samples failing in phase II. The most commonly identified indicator organism was Pseudomonas spp., mainly Pseudomonas oleovorans. None of the tested viruses were detected in 40 samples. While AERs in phase I failed (n = 9, 17.6%) mainly due to technical faults, phase II revealed lapses (n = 6, 11.5%) only on account of microbial contamination of the last rinsing water, mainly with Pseudomonas spp. In the present study the contamination rate of endoscopes was low compared with results from other European countries, possibly due to the high quality of endoscope reprocessing, drying and storage. Copyright © 2018 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

New digital cholangiopancreatoscopy for diagnosis and therapy of pancreaticobiliary diseases (with videos).

PubMed

Tanaka, Reina; Itoi, Takao; Honjo, Mitsusyoshi; Tsuchiya, Takayoshi; Kurihara, Toshio; Tsuji, Shujiro; Tonozuka, Ryosuke; Kamada, Kentato; Sofuni, Atsushi; Mukai, Shuntaro

2016-04-01

Recently, a new digital cholangiopancreatoscopy (DCPS) has been developed. The aim of this study is to retrospectively evaluate the utility of new DCPS in patients with pancreaticobiliary diseases. Digital cholangiopancreatoscopy was used in 26 patients (16 men) with pancreaticobiliary diseases that could not be diagnosed and treated by standard endoscopic retrograde cholangiopancreatography (ERCP). The procedures included DCPS-guided tissue sampling and interventions. Technical success and adverse events were evaluated. Among the 26 patients, 19 patients were classified for diagnostic purposes and seven for therapeutic purposes. The detailed breakdown of the particular conditions and numbers of patients was as follows: indeterminate bile duct (BD) lesion, indeterminate pancreatic duct (PD) lesion, lithotripsy by yttrium aluminum garnet-laser or electrohydraulic lithotripsy, removal of migrated BD stent and PD stent, and guidewire passing across the biliary stricture. The overall technical success rates of visualizing the target lesions and therapeutic interventions were 100% and 85.7%, respectively. The incidence of procedure-related adverse events among the patients was 7.7% (2/26). Cholangitis developed in one of the patients and post-endoscopic sphincterotomy bleeding in one patient. All adverse events were successfully treated by conservative therapy. Digital cholangiopancreatoscopy has a high potential for providing an accurate diagnosis and facilitating therapy in patients with pancreaticobiliary diseases. © 2016 Japanese Society of Hepato-Biliary-Pancreatic Surgery.

Quantitative evaluation of the safety of mucosal incision and submucosal dissection for colon during endoscopic submucosal dissection using carbon dioxide laser

NASA Astrophysics Data System (ADS)

Noguchi, Takuma; Honda, Norihiro; Hazama, Hisanao; Morita, Yoshinori; Awazu, Kunio

2018-02-01

Since the increase in the overall mortality rate in patients with colon cancer is remarkably high in recent years, early treatment is required. For this reason, endoscopic submucosal dissection (ESD) has been at the forefront of international attention as a low invasive treatment for early digestive cancer. In current ESD procedure, an electrosurgical knife is used for mucosal incision and subsequent submucosal dissection. However, the perforation has been reported to occur by approximately 5%. Thus, to enhance the tissue selectivity of this modality, we focused on the application of laser for ESD. A carbon dioxide laser was chosen as a surgical knife because the saline or a sodium hyaluronate solution injected into the submucosal layer in current ESD procedure has a high absorption coefficient at the wavelength of the carbon dioxide laser. In this research, ex vivo experiment was performed at the output power of 3-7 W and discuss the optimum irradiation power of laser. As a result of ex vivo experiment using extracted porcine colon tissues, mucosal incision and submucosal dissection were safely and less invasively performed in every output power, without reaching the thermal damage to a muscular layer. This is because a carbon dioxide laser is strongly absorbed by saline injected into submucosa. ESD using a carbon dioxide laser is a safer method for the treatment of early colon cancer. We are planning to measure and compare the optical and thermal properties of porcine colon with those of human colon.

Experimental application of pulsed laser-induced water jet for endoscopic submucosal dissection: mechanical investigation and preliminary experiment in swine.

PubMed

Sato, Chiaki; Nakano, Toru; Nakagawa, Atsuhiro; Yamada, Masato; Yamamoto, Hiroaki; Kamei, Takashi; Miyata, Go; Sato, Akira; Fujishima, Fumiyoshi; Nakai, Masaaki; Niinomi, Mitsuo; Takayama, Kazuyoshi; Tominaga, Teiji; Satomi, Susumu

2013-05-01

A current drawback of endoscopic submucosal dissection (ESD) for early-stage gastrointestinal tumors is the lack of instruments that can safely assist with this procedure. We have developed a pulsed jet device that can be incorporated into a gastrointestinal endoscope. Here, we investigated the mechanical profile of the pulsed jet device and demonstrated the usefulness of this instrument in esophageal ESD in swine. The device comprises a 5-Fr catheter, a 14-mm long stainless steel tube for generating the pulsed water jet, a nozzle and an optical quartz fiber. The pulsed water jet was generated at pulse rates of 3 Hz by irradiating the physiological saline (4°C) within the stainless steel tube with an holmium-doped yttrium-aluminum-garnet (Ho:YAG) laser at 1.1 J/pulse. Mechanical characteristics were evaluated using a force meter. The device was used only for the part of submucosal dissection in the swine ESD model. Tissues removed using the pulsed jet device and a conventional electrocautery device, and the esophagus, were histologically examined to assess thermal damage. The peak impact force was observed at a stand-off distance of 40 mm (1.1 J/pulse). ESD using the pulsed jet device was successful, as the tissue specimens showed precise dissection of the submucosal layer. The extent of thermal injury was significantly lower in the dissected bed using the pulsed jet device. The results showed that the present endoscopic pulsed jet system is a useful alternative for a safe ESD with minimum tissue injury. © 2012 The Authors. Digestive Endoscopy © 2012 Japan Gastroenterological Endoscopy Society.

[Place of the ureteroscopy in the treatment of the children urolithiasis].

PubMed

Fotso Kamdem, A; Tekaili, Y; Boillot, B; Dodat, H; Aubert, D

2010-03-01

To determine the efficiency and the role of ureteroscopy in the treatment of urolithiasis in children. A multicenter retrospective study was conducted between January 2006 and March 2008 in the department of pediatric surgery and urology of Besançon, Lyon and Grenoble. The clinical data of 17 children having benefited from one or more ureteroscopy procedures for urolithiasis were analyzed. These data concerned age, sex, antecedents of metabolic diseases, existence of a malformed uropathy, how the urolithiasis was discovered, therapeutic indications, endoscopic procedures, type of endoscopic treatment for urolithiasis, results and complications. Twenty-six ureteroscopies were carried out for 17 children (eight girls and nine boys) aged between 9 months and 12 years (mean: 5 (1/2) years old) as a first-line treatment or after extracorporeal shock wave lithotripsy. A 6/7,5 Fr semi-rigid ureteroscope was used in all case. Only once, the operator chose a flexible ureteroscope. Lithotripsy was carried out 15 times with YAG Holmium laser, four times with Swiss Lithoclast and six times by simple extraction with a Dormia type basket .A stent probe was left in place after endoscopy for 14 children. The "stone free" rate was 88% with an average hindsight of 11 months. Two incidents without major complication were recorded: a section of the guide by the laser beam and a perforation with extravasation of the contrast agent. Ureteroscopy is the first-line treatment in isolated ureteral urolithiasis. On the other hand, LEC remains the treatment of choice for Starghon calculi, since LIC should be offered only in the event of failure of LEC. Copyright 2009. Published by Elsevier Masson SAS.

Optimization of a novel Tm fiber laser lithotripter in terms of stone ablation efficiency and retropulsion reduction

NASA Astrophysics Data System (ADS)

Yaroslavsky, Ilya; Vinnichenko, Victoria; McNeill, Tyler; Novoseltseva, Anna; Perchuk, Igor; Vybornov, Alexander; Altshuler, Gregory; Gapontsev, Valentin

2018-02-01

Recently, a Thulium (Tm) fiber laser operating at a wavelength of 1940 nm and peak power up to 500 W has been introduced as a promising energy source for laser lithotripsy. Direct comparative studies have demonstrated considerable advantages of Tm fiber laser over the current industry-standard 2100 nm Holmium:YAG (Ho:YAG) device in terms of ablation rate and retropulsion effects. In this work, we investigated avenues of further improving stone ablation efficiency and reducing retropulsion. Specifically, the roles of temporal pulse structure and fiber tip preparation were studied in detail. Experiments were conducted on Bego stone phantoms in an aqueous environment using a computerized 2D stage for controlled scanning of the fiber over the stone surface. High-resolution 3D-enabled optical microscopy was employed to assess both fiber tip damage and stone ablation rate. Retropulsion effects were quantified using a high-speed video camera. Fiber burn back was evaluated as well. Fiber performance could be preserved during prolonged (up to 15 min) procedures when the fiber tip was adequately prepared. Furthermore, the results were compared with available literature for similar experiments performed with the Ho:YAG laser. The data obtained provide an important foundation for optimizing clinical performance of Tm fiber systems for lithotripsy.

Numerical Response Surfaces of Volume of Ablation and Retropulsion Amplitude by Settings of Ho:YAG Laser Lithotripter

PubMed Central

Rutherford, Jonathan; Solomon, Metasebya; Cheng, Brian; Xuan, Jason R.; Gong, Jason; Yu, Honggang; Xia, Michael L. D.; Yang, Xirong; Hasenberg, Thomas; Curran, Sean

2018-01-01

Objectives Although laser lithotripsy is now the preferred treatment option for urolithiasis due to shorter operation time and a better stone-free rate, the optimal laser settings for URS (ureteroscopic lithotripsy) for less operation time remain unclear. The aim of this study was to look for quantitative responses of calculus ablation and retropulsion by performing operator-independent experiments to determine the best fit versus the pulse energy, pulse width, and the number of pulses. Methods A lab-built Ho:YAG laser was used as the laser pulse source, with a pulse energy from 0.2 J up to 3.0 J and a pulse width of 150 μs up to 1000 μs. The retropulsion was monitored using a high-speed camera, and the laser-induced craters were evaluated with a 3-D digital microscope. The best fit to the experimental data is done by a design of experiment software. Results The numerical formulas for the response surfaces of ablation speed and retropulsion amplitude are generated. Conclusions The longer the pulse, the less the ablation or retropulsion, while the longer pulse makes the ablation decrease faster than the retropulsion. The best quadratic fit of the response surface for the volume of ablation varied nonlinearly with pulse duration and pulse number. PMID:29707187

[EFFECTIVENESS OF EXTRACORPOREAL SHOCK WAVE LITHOTRIPSY IN PATIENTS WITH UROLITHIASIS OF A SOLITARY KIDNEY].

PubMed

Parshenkova, I G; Dutov, V V; Rumjancev, A A; Mamedov, E A

2015-01-01

The article presents results of extracorporeal shock wave lithotripsy (ESWL) in 62 patients with urolithiasis of a solitary kidney. In 50 (80.6%) patients calculi were located in the kidney and in 12 (19.4%) patients in the ureter. Effectiveness of ESWL at 3 month follow-up was 85.5%, which is somewhat lower than in patients with two healthy kidneys due to the choice of sparing low-energy modes of lithotripsy. The effectiveness of ESWL depended on the size of the original calculi (p<0.0001), and the baseline urodynamics of the upper urinary tract (p<0.0001). The rates of complications (32.3%) and auxiliary procedures (16.1%) were relatively low, due to the usage of pre-drainage of the kidney before a session of ESWL in patients with large and multiple calculi. There was no correlation between the occurrence of complications during treatment and the clinical form of a solitary kidney (p>0.05). In patients with stones larger than 1 cm and a moderate baseline abnormalities of the upper urinary tract urodynamics ESWL was less effective (p<0.0001), they had increased time of lithotripsy (p=0.013), more sessions (p<0.0001), complications (19.4%, p=0.043) and auxiliary manipulation (9.7%). Nevertheless, the duration of stay in hospital in the postoperative period did not correlate with the size of calculus (p=0.504). Extracorporeal shock wave lithotripsy is a highly effective and safe treatment of stones of a solitary kidney. Rational choice of indications and contraindications for the use of ESWL in a specific clinical situation is of great importance.

Orbital endoscopic surgery

PubMed Central

Selva, Dinesh

2008-01-01

Minimally invasive ″keyhole″ surgery performed using endoscopic visualization is increasing in popularity and is being used by almost all surgical subspecialties. Within ophthalmology, however, endoscopic surgery is not commonly performed and there is little literature on the use of the endoscope in orbital surgery. Transorbital use of the endoscope can greatly aid in visualizing orbital roof lesions and minimizing the need for bone removal. The endoscope is also useful during decompression procedures and as a teaching aid to train orbital surgeons. In this article, we review the history of endoscopic orbital surgery and provide an overview of the technique and describe situations where the endoscope can act as a useful adjunct to orbital surgery. PMID:18158397

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.

Laser induced fluorescence as a diagnostic tool integrated into a scanning fiber endoscope for mouse imaging

NASA Astrophysics Data System (ADS)

Brown, Christopher M.; Maggio-Price, Lillian; Seibel, Eric J.

2007-02-01

Scanning fiber endoscope (SFE) technology has shown promise as a minimally invasive optical imaging tool. To date, it is capable of capturing full-color 500-line images, at 15 Hz frame rate in vivo, as a 1.6 mm diameter endoscope. The SFE uses a singlemode optical fiber actuated at mechanical resonance to scan a light spot over tissue while backscattered or fluorescent light at each pixel is detected in time series using several multimode optical fibers. We are extending the capability of the SFE from a RGB reflectance imaging device to a diagnostic tool by imaging laser induced fluorescence (LIF) in tissue, allowing for correlation of endogenous fluorescence to tissue state. Design of the SFE for diagnostic imaging is guided by a comparison of single point spectra acquired from an inflammatory bowel disease (IBD) model to tissue histology evaluated by a pathologist. LIF spectra were acquired by illuminating tissue with a 405 nm light source and detecting intrinsic fluorescence with a multimode optical fiber. The IBD model used in this study was mdr1a-/- mice, where IBD was modulated by infection with Helicobacter bilis. IBD lesions in the mouse model ranged from mild to marked hyperplasia and dysplasia, from the distal colon to the cecum. A principle components analysis (PCA) was conducted on single point spectra of control and IBD tissue. PCA allowed for differentiation between healthy and dysplastic tissue, indicating that emission wavelengths from 620 - 650 nm were best able to differentiate diseased tissue and inflammation from normal healthy tissue.

Selective mucosal ablation using CO2 laser for the development of novel endoscopic submucosal dissection: comparison of continuous wave and nanosecond pulsed wave

NASA Astrophysics Data System (ADS)

Ishii, K.; Watanabe, S.; Obata, D.; Hazama, H.; Morita, Y.; Matsuoka, Y.; Kutsumi, H.; Azuma, T.; Awazu, K.

2010-02-01

Endoscopic submucosal dissection (ESD) is accepted as a minimally invasive treatment technique for small early gastric cancers. Procedures are carried out using some specialized electrosurgical knifes with a submucosal injection solution. However it is not widely used because its procedure is difficult. The objective of this study is to develop a novel ESD method which is safe in principle and widely used by using laser techniques. In this study, we used CO2 lasers with a wavelength of 10.6 μm for mucosal ablation. Two types of pulse, continuous wave and pulsed wave with a pulse width of 110 ns, were studied to compare their values. Porcine stomach tissues were used as a sample. Aqueous solution of sodium hyaluronate (MucoUpR) with 50 mg/ml sodium dihydrogenphosphate is injected to a submucosal layer. As a result, ablation effect by CO2 laser irradiation was stopped because submucosal injection solution completely absorbed CO2 laser energy in the invasive energy condition which perforates a muscle layer without submucosal injection solution. Mucosal ablation by the combination of CO2 Laser and a submucosal injection solution is a feasible technique for treating early gastric cancers safely because it provides a selective mucosal resection and less-invasive interaction to muscle layer.

Successful endoscopic removal of a rare, large impacted pancreatic duct stone using grasping forceps: A case report with video.

PubMed

Liu, Qin; Wang, Yiping; Zeng, Hongze; Hu, Bing

2018-04-01

As a main complication of chronic pancreatitis (CP), pancreatic duct stones (PDSs) are often associated with ductal obstruction resulting in increasing intraductal and parenchymal pressure and long-lasting pain. There are many methods for removing PDSs. However, for large stones, it is technically difficult to remove them entirely by endoscopic retrograde cholangiopancreatography (ERCP). A 57-year-old man presented with a chief complaint of severe epigastric pain radiating to his back 3 or 4 times annually for 2 years. The abdominal computed tomography scan revealed dilation of the proximal pancreatic duct with an irregular high-density calcification shadow located at the head of the pancreas. A pancreatic stent was placed initially by ERCP to relieve epigastric pain and alleviate symptom. Repeated ERCP was subsequently performed 2 months later to extract the impacted large pancreatic stone. By using grasping forceps, the huge coralloid stone (272 × 0 mm) was successfully extracted in an en bloc manner. Then, a 7-French × 5 cm plastic pancreatic stent was placed for 2 weeks. The patient was free of any pancreatic pain during the 2-year follow-up. Generally, for large or impacted pancreatic stones, endoscopic removal is technically difficult to achieve. Pancreatic stenting can be an effective method of alleviating abdominal pain and facilitating subsequent endoscopic lithoextraction. Extraction of large stones with grasping forceps can be an alternative approach instead of extracorporeal shock wave lithotripsy or surgery when stones are impacted at the papilla's orifice and partially protruding into the duodenal lumen.

Advanced endoscopic imaging: European Society of Gastrointestinal Endoscopy (ESGE) Technology Review.

PubMed

East, James E; Vleugels, Jasper L; Roelandt, Philip; Bhandari, Pradeep; Bisschops, Raf; Dekker, Evelien; Hassan, Cesare; Horgan, Gareth; Kiesslich, Ralf; Longcroft-Wheaton, Gaius; Wilson, Ana; Dumonceau, Jean-Marc

2016-11-01

Background and aim: This technical review is an official statement of the European Society of Gastrointestinal Endoscopy (ESGE). It addresses the utilization of advanced endoscopic imaging in gastrointestinal (GI) endoscopy. Methods: This technical review is based on a systematic literature search to evaluate the evidence supporting the use of advanced endoscopic imaging throughout the GI tract. Technologies considered include narrowed-spectrum endoscopy (narrow band imaging [NBI]; flexible spectral imaging color enhancement [FICE]; i-Scan digital contrast [I-SCAN]), autofluorescence imaging (AFI), and confocal laser endomicroscopy (CLE). The Grading of Recommendations Assessment, Development and Evaluation (GRADE) system was adopted to define the strength of recommendation and the quality of evidence. Main recommendations: 1. We suggest advanced endoscopic imaging technologies improve mucosal visualization and enhance fine structural and microvascular detail. Expert endoscopic diagnosis may be improved by advanced imaging, but as yet in community-based practice no technology has been shown consistently to be diagnostically superior to current practice with high definition white light. (Low quality evidence.) 2. We recommend the use of validated classification systems to support the use of optical diagnosis with advanced endoscopic imaging in the upper and lower GI tracts (strong recommendation, moderate quality evidence). 3. We suggest that training improves performance in the use of advanced endoscopic imaging techniques and that it is a prerequisite for use in clinical practice. A learning curve exists and training alone does not guarantee sustained high performances in clinical practice. (Weak recommendation, low quality evidence.) Conclusion: Advanced endoscopic imaging can improve mucosal visualization and endoscopic diagnosis; however it requires training and the use of validated classification systems. © Georg Thieme Verlag KG Stuttgart · New York.

Confocal laser endomicroscopy and ultrasound endoscopy during the same endoscopic session for diagnosis and staging of gastric neoplastic lesions.

PubMed

Gheorghe, C; Iacob, R; Dumbrava, Mona; Becheanu, G; Ionescu, M

2009-01-01

Confocal LASER endomicroscopy (CLE) is a newly developed endoscopic technique which allows subsurface in vivo histological assessment during ongoing endoscopy and targeted biopsies. Ultrasound endoscopy (EUS) is a useful tool in staging upper GI malignant lesions. We describe for the first time the use of both techniques during the same endoscopic session, in a pilot study, in order to increase the diagnostic yield of histological assessment and provide the staging of the gastric neoplastic lesions thus decreasing the time to therapeutic decision. CLE has been performed with the Pentax EG-3870CIK confocal endomicroscope after a 5 ml intravenous 10% fluorescein injection; EUS has been performed subsequently, during the same endoscopic Propofol sedation session, using a standard radial EUS-scope. Eleven patients have been investigated, 4 females, 7 males, mean age 59.7 +/- 12.3 years. The indication of CLE/EUS exploration was the presence of a gastric polypoid lesion in 37% of cases, atypical gastric ulcer in 27% of patients, gastric lymphoma 18%, suspicion of gastric cancer recurrence after resection 9% and infiltrating type gastric cancer 9%. Histological assessment after targeted biopsy has established the diagnosis of gastric adenocarcinoma in 55% of cases, gastric lymphoma in 18% of cases, gastric adenoma, gastric GIST and gastric foveolar hyperplasia in 9% of cases respectively. CLE has allowed targeted biopsies in 81.8% of cases. In 2 patients - one case with suspected recurrent gastric cancer after surgery and one case of gastric lymphoma, CLE has indicated normal gastric mucosa. The EUS evaluation has shown TO lesion in two cases, T1 in 3 cases, T2 in 3 cases, T3 in one case. The EUS evaluation showed in one gastric lymphoma patient a lesion interesting the mucosa and submucosa with regional adenopathy and a submucosal lesion with regional adenopathy in the other gastric lymphoma case. The therapeutic decision was surgery in 73% of cases, chemotherapy and

Effects of shielded or unshielded laser and electrohydraulic lithotripsy on rabbit bladder.

PubMed

Bhatta, K M; Rosen, D I; Flotte, T J; Dretler, S P; Nishioka, N S

1990-04-01

The pulsed dye laser and electrohydraulic lithotriptor (EHL) are both effective devices for fragmenting urinary and biliary calculi. Both fragment stones by producing a plasma-mediated shockwave. Recently, a plasma shield consisting of a hollow spring and a metal end cap has been described for use with the laser and EHL devices in an attempt to minimize tissue damage without adversely affecting stone fragmentation rates. The tissue effects produced by a pulsed dye laser and an EHL device with and without plasma shields were examined and compared using rabbit urinary bladders. If blood was present, the unshielded laser perforated the bladder wall in two pulses. However, in the absence of blood, over 100 pulses were needed for the laser to perforate the bladder. A mean of six pulses were required to perforate the bladder wall with a shielded laser. The unshielded EHL perforated the bladder wall in two pulses, whereas, the shielded EHL required a mean of 35 pulses. Microscopically, areas of exposure revealed hemorrhage and tissue ablation. We conclude that all devices examined can produce significant tissue damage when discharged directly onto bladder epithelium.

[Questions of terminology, systematization and grading of complications of contact ureteral lithotripsy].

PubMed

Dutov, V V; Bazaev, V V; Mamedov, E A; Urenkov, S B; Podoinitsyn, A A

2017-07-01

To investigate the advantages and disadvantages of the current variants of systematization and grading of complications of contact ureteral lithotripsy (CULT) and develop a working classification of CULT complications. The study analyzed results of 545 fluoroscopy-guided endoscopic procedures performed at the MRRCI Clinic of Urology from 2008 to 2015 in 506 patients with ureterolithiasis. The proposed and implemented classification and terminology of CULT complications unifies the diagnostic and management algorithm. This tool is more systematic and structured than the classical classification and universal methods of systematization and grading of CULT complications (classifying CULT complications in "major" and "minor", PULS scale, Satava and Clavien-Dindo grading systems). Given the lack of clear grading of ureteral rupture, it was divided into amputation (two-level rupture) and avulsion (one-level rupture). Using such term as extravasation of the contrast media and/or migration of the stone outside of the ureter is groundless because these complications occur only after the perforation of the ureteral wall. Therefore, these conditions are complications not of CULT, but of the ureteral wall perforation. The ureteral perforation was classified into macro- and micro-perforation. The existing terminology, classification and grading of the CULT complications should undergo a more detailed analysis. None of the existing classifications of CULT complications afford them to be fully staged and systematized. The working classification of complications of CULT developed at the M.F. Vladimirsky MRRCI Clinic of Urology warrants a multi-center prospective study to validate it and investigate its effectiveness.

Use of ureteral stent in extracorporeal shock wave lithotripsy for upper urinary calculi: a systematic review and meta-analysis.

PubMed

Shen, Pengfei; Jiang, Min; Yang, Jie; Li, Xiong; Li, Yutao; Wei, Wuran; Dai, Yi; Zeng, Hao; Wang, Jia

2011-10-01

This systematic review was performed to assess the necessity and complications of stenting before extracorporeal shock wave lithotripsy in the management of upper urinary stones. A systematic research of PubMed®, EMBASE® and the Cochrane Library was performed to identify all randomized controlled trials. The comparisons were about the outcomes and complications of extracorporeal shock wave lithotripsy in the management of upper urinary stones with or without Double-J stenting before extracorporeal shock wave lithotripsy, including stone-free rate, Steinstrasse, lower urinary tract symptoms, hematuria, fever, urinary tract infection, pain and analgesia, auxiliary treatment, and nausea and vomiting. We used the Cochrane Collaboration's Review Manager (RevMan) 5.0.2 software for statistical analysis. Eight randomized controlled trials were included in analysis that reported 876 patients in total, divided into the stented group of 453 and the stentless group of 423. All studies recorded the stone-free rate and the results of the meta-analysis showed no difference between the groups (RR 0.97, 95% CI 0.91-1.03, p = 0.27). The total incidence of Steinstrasse in the stented group was similar to that of the stentless group with the exception of 1 study. However, the incidence of lower urinary tract symptoms was significantly higher in the stented group than in the stentless group (RR 4.10, 95% CI 2.21-7.61, p <0.00001). Significant differences could not be found in hematuria, fever, urinary tract infection, pain and analgesia, auxiliary treatment, or nausea and vomiting between the groups. The systematic review suggested significant advantages of stenting before extracorporeal shock wave lithotripsy compared to in situ extracorporeal shock wave lithotripsy in terms of Steinstrasse. However, stenting did not benefit stone-free rate and auxiliary treatment after extracorporeal shock wave lithotripsy, and it induced more lower urinary tract symptoms. More high quality

Excimer laser in arthroscopic surgery

NASA Astrophysics Data System (ADS)

Koort, Hans J.

1991-05-01

The development of efficient high-power lasersystems for use in surgery, especially in arthroscopic fields, leads to a new push for all endoscopic techniques. Both techniques, laser and endoscope, complete each other in an ideal way and allow applications which could not be reached with conventional techniques. One of the newer laser types is the excimer laser, which will be a good choice for surface treatment because of its very considerate interaction with tissue. One example is the ablation or smoothing of articular cartilage and meniscal shaving in orthopaedics. On the other hand, the power of this laser system is high enough to cut tissue, for instance in the lateral release, and offers therefore an alternative to the mechanical and electrical instruments. All lasers can only work fine with effective delivery systems. Sometimes there is only a single fiber, which becomes very stiff at diameters of more than 800 micrometers . This fiber often allows only the tangential treatment of tissue, most of the laser power is lost in the background. New fiber systems with many, sometimes hundreds of very thin single fibers, could offer a solution. Special handpieces and fibersystems offer distinct advantages in small joint arthroscopy, especially those for use with excimer lasers will be discussed.

Prospective analysis of a complete retrograde ureteroscopic technique with holmium laser stent cutting for management of encrusted ureteral stents.

PubMed

Thomas, Alexandre; Cloutier, Jonathan; Villa, Luca; Letendre, Julien; Ploumidis, Achilles; Traxer, Olivier

2017-03-14

To propose and evaluate a new endoscopic technique using only a retrograde ureteroscopic approach for the removal of heavily encrusted ureteral stents. Data from 51 consecutive patients with encrusted and retained ureteral stents were prospectively collected. Description of the successive steps of surgery is detailed. The Holmium-YAG laser properties offer the opportunity for fragmentation of stent-attached encrustation and the ability to cut the stent itself. Reducing the length of the stent is critical to creating space in the ureter and to allow free access for ureteroscopes or ureteral access sheath placement. The primary outcome of this study was the feasibility and the safety of this retrograde intra-renal approach. Some factors of encrustation and outcomes are also discussed in comparison with lithotripsy, percutaneous, laparoscopic, open surgery or a combination of these techniques. The removal of the encrusted stent was possible with only this retrograde technique in 98% of patients. The transection of the encrusted stent with the Holmium-YAG laser was useful in 71% of the patients. Mean operative time was 110 minutes and mean hospital stay was 2.33 days. Postoperative complications were mainly non-obstructive pyelonephritis (10%). The most significant predictor of this life threatened complication was the presence of struvite stones with the encrusted stent (p=0,018). Contrariwise, operative time, BMI, gender and encrustation rate were not associated with postoperative pyelonephritis. Cystine stone disease or pregnancy both led to faster stent encrustation. Retrograde ureteroscopic surgery is efficient and safe for removing retained stents and associated stone burdens. The Holmium-YAG laser is essential to perform the encrustation removal and sectioning of the stent.

Comparison of the Nanopulse Lithotripter to the Holmium Laser: Stone Fragmentation Efficiency and Impact on Flexible Ureteroscope Deflection and Flow.

PubMed

Kaplan, Adam G; Chen, Tony T; Sankin, Georgy; Yang, Chen; Dale, Joanne A; Simmons, W Neal; Zhong, Pei; Preminger, Glenn M; Lipkin, Michael Eric

2016-11-01

The Nanopulse Lithotripter (NPL; Lithotech Medical, Israel) is a novel intracorporeal device that uses a nanosecond duration electrical discharge through a reusable flexible coaxial probe to endoscopically fragment urinary stones. This device was compared with a holmium laser lithotripsy (HoL) with regard to stone fragmentation efficiency (SFE) and its impact on flexible ureteroscope (URS) deflection and flow of irrigation. Using a custom bench model, a 6 mm BegoStone cylindrical phantom (mixture 5:2) was confined under 0.9% saline atop sequential mesh sieves. The SFE of two NPL probe sizes (2.0F, 3.6F) and two HoL fibers (200, 365 μm) was evaluated using concordant settings of 1 J and 5 Hz. URS deflection and irrigation flow with NPL probes in the working channel were tested in five new fourth generation flexible URS and compared with other adjunct endourologic instruments. The 2.0F NPL showed improved SFE compared with the 200 μm laser (86 mg/min vs 52 mg/min, p = 0.014) as did the 3.6F NPL vs the 365 μm laser (173 mg/min vs 80 mg/min, p = 0.05). The NPL created more 1 to 2 mm fragments; the laser created more dust. URS deflection reduced by 3.75° with the 2.0 NPL probe. URS irrigation flow reduced from 36.5 to 6.3 mL/min with the 2.0F NPL probe. NPL shows improved SFE compared with HoL. Flow with the 2.0F probe is akin to a stone basket. NPL offers an effective alternative to HoL.

Tracking kidney stones with sound during shock wave lithotripsy

NASA Astrophysics Data System (ADS)

Kracht, Jonathan M.

The prevalence of kidney stones has increased significantly over the past decades. One of the primary treatments for kidney stones is shock wave lithotripsy which focuses acoustic shock waves onto the stone in order to fragment it into pieces that are small enough to pass naturally. This typically requires a few thousand shock waves delivered at a rate of about 2 Hz. Although lithotripsy is the only non-invasive treatment option for kidney stories, both acute and chronic complications have been identified which could be reduced if fewer shock waves were used. One factor that could be used to reduce the number of shock waves is accounting for the motion of the stone which causes a portion of the delivered shock waves to miss the stone, yielding no therapeutic benefit. Therefore identifying when the stone is not in focus would allow tissue to be spared without affecting fragmentation. The goal of this thesis is to investigate acoustic methods to track the stone in real-time during lithotripsy in order to minimize poorly-targeted shock waves. A relatively small number of low frequency ultrasound transducers were used in pulse-echo mode and a novel optimization routine based on time-of-flight triangulation is used to determine stone location. It was shown that the accuracy of the localization may be estimated without knowing the true stone location. This method performed well in preliminary experiments but the inclusion of tissue-like aberrating layers reduced the accuracy of the localization. Therefore a hybrid imaging technique employing DORT (Decomposition of the Time Reversal Operator) and the MUSIC (Multiple Signal Classification) algorithm was developed. This method was able to localize kidney stories to within a few millimeters even in the presence of an aberrating layer. This would be sufficient accuracy for targeting lithotripter shock waves. The conclusion of this work is that tracking kidney stones with low frequency ultrasound should be effective clinically.

Advances in lithotripsy and stone disease treatment.

PubMed

Newman, J

1996-01-01

Stone disease can be traced back as far as the human record. This article traces the diagnosis and treatment of stone disease from primitive attempts at stone removal in ancient civilizations to the advent of extracorporeal shock wave lithotripsy (ESWL) in the 1970s. ESWL revolutionized the treatment of stone disease, offering patients a less painful alternative to the traditional surgical removal of stones. This article discusses recent advances in ESWL, describes the radiologic technologist's role in diagnosing and managing stone disease, and outlines future prospects in the treatment of stone disease.

The study of laser pulse width on efficiency of Ho:YAG laser lithotripsy

NASA Astrophysics Data System (ADS)

Zhang, Jian J.; Rutherford, Jonathan; Solomon, Metasebya; Cheng, Brian; Xuan, Jason R.; Gong, Jason; Yu, Honggang; Xia, Michael; Yang, Xirong; Hasenberg, Thomas; Curran, Sean

2017-02-01

When treating ureteral calculi, retropulsion can be reduced by using a longer pulse width without compromising fragmentation efficiency (from the studies by David S. Finley et al. and Hyun Wook Kang et al.). In this study, a lab build Ho:YAG laser was used as the laser pulse source, with pulse energy from 0.2J up to 3.0 J, and electrical pump pulse width from 150 us up to 1000 us. The fiber used in the investigation is a 365 μm core diameter fiber, SureFlexTM, Model S-LLF365. Plaster of Paris calculus phantoms were ablated at different energy levels (0.2, 0.5, 1, 2, 3J) and with different number of pulses (1, 3, 10) using different electrical pump pulse width (333, 667, 1000 μs). The dynamics of the recoil action of a calculus phantom was monitored using a high-speed camera with frame rate up to 1 million frame per second (Photron Fastcam SA5); and the laser-induced craters were evaluated with a 3-D digital microscope (Keyence VHX-900F). A design of experiment software (DesignExpert-10, Minneapolis, MN, USA) is used in this study for the best fit of surface response on volume of dusting and retropulsion amplitude. The numerical formulas for the response surfaces of dusting speed and retropulsion amplitude are generated. More detailed investigation on the optimal conditions for dusting of other kinds of stone samples and the fiber size effect will be conducted as a future study.

Novel Concept of Attaching Endoscope Holder to Microscope for Two Handed Endoscopic Tympanoplasty.

PubMed

Khan, Mubarak M; Parab, Sapna R

2016-06-01

The well established techniques in tympanoplasty are routinely performed with operating microscopes for many decades now. Endoscopic ear surgeries provide minimally invasive approach to the middle ear and evolving new science in the field of otology. The disadvantage of endoscopic ear surgeries is that it is one-handed surgical technique as the non-dominant left hand of the surgeon is utilized for holding and manipulating the endoscope. This necessitated the need for development of the endoscope holder which would allow both hands of surgeon to be free for surgical manipulation and also allow alternate use of microscope during tympanoplasty. To report the preliminary utility of our designed and developed endoscope holder attachment gripping to microscope for two handed technique of endoscopic tympanoplasty. Prospective Non Randomized Clinical Study. Our endoscope holder attachment for microscope was designed and developed to aid in endoscopic ear surgery and to overcome the disadvantage of single handed endoscopic surgery. It was tested for endoscopic Tympanoplasty. The design of the endoscope holder attachment is described in detail along with its manipulation and manoeuvreing. A total of 78 endoholder assisted type 1 endoscopic cartilage tympanoplasties were operated to evaluate its feasibility for the two handed technique and to evaluate the results of endoscopic type 1 cartilage tympanoplasty. In early follow up period ranging from 6 to 20 months, the graft uptake was seen in 76 ears with one residual perforation and 1 recurrent perforations giving a success rate of 97.435 %. Our endocsope holder attachment for gripping microscope is a good option for two handed technique in endoscopic type 1 cartilage tympanoplasty. The study reports the successful application and use of our endoscope holder attachment for gripping microscope in two handed technique of endoscopic type 1 cartilage tympanoplasty and comparable results with microscopic techniques. IV.

Automated high-level disinfection of nonchanneled flexible endoscopes: duty cycles and endoscope repair.

PubMed

Statham, Melissa McCarty; Willging, J Paul

2010-10-01

Guidelines issued by the Association of Operating Room Nurses and the Association of Professionals in Infection Control and Epidemiology recommend high-level disinfection (HLD) for semicritical instruments, such as flexible endoscopes. We aim to examine the durability of endoscopes to continued use and automated HLD. We report the number of duty cycles a flexible endoscope can withstand before repairs should be anticipated. Retrospective review. A total of 4,336 endoscopic exams and subsequent disinfection cycles were performed with 60 flexible endoscopes in an outpatient tertiary pediatric otolaryngology practice from 2005 to 2009. All endoscopes were systemically cleaned with mechanical cleansing followed by leak testing, enzymatic cleaning, and exposure to Orthophthaldehyde (0.55%) for 5 minutes at a temperature of at least 25°C, followed by rinsing for 3 minutes. A total of 77 repairs were performed, 48 major (average cost $3,815.97), and 29 minor (average cost $326.85). On average, the 2.2-mm flexible endoscopes were utilized for 61.9 examinations before major repair was needed, whereas the 3.6 mm endoscopes were utilized for 154.5 exams before needing minor repairs. No major repairs have been needed to date on the 3.6-mm endoscopes. Automated endoscope reprocessor use for HLD is an effective means to disinfect and process flexible endoscopes. This minimizes variability in the processing of the endoscopes and maximizes the rate of successful HLD. Even when utilizing standardized, automated HLD and limiting the number of personnel processing the endoscopes, smaller fiberoptic endoscopes demonstrate a shortened time interval between repairs than that seen with the larger endoscopes. Laryngoscope, 2010.

Endoscopic neurosurgery "around the corner" with a rigid endoscope. Technical note.

PubMed

Hopf, N J

1999-03-01

Endoscopically "working around the corner" is presently restricted to the use of flexible endoscopes or an endoscope-assisted microneurosurgical (EAM) technique. In order to overcome the limitations of these solutions, endoscopic equipment and techniques were developed for "working around the corner" with rigid endoscopes. A steering insert with a 5 French working channel is capable of steering instruments around the corner by actively bending the guiding track and consecutively the instrument. A special fixation device enables strict axial rotation of the endoscope in the operating field. Endoscopic procedures "around the corner", including aqueductal stenting, pellucidotomy, third ventriculostomy and biopsy were performed in human cadavers. Special features of the used pediatric neuroendoscope system, i.e., reliable fixation, axial rotation, and controlled steering of instruments, increase the safety and reduce the surgical traumatization in selected cases, such as obstructive hydrocephalus due to a mass lesion in the posterior third ventricle, since endoscopic third ventriculostomy and biopsy can be performed through the same burr hole trephination. Limitations of this technique are given by the size of the foramen of Monro and the height of the third ventricle as well as by the bending angle of the instruments (40-50 degrees).

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

Image-guided intervention in the human bile duct using scanning fiber endoscope system

NASA Astrophysics Data System (ADS)

Seibel, Eric J.; Jo, Javier A.; Melville, C. David; Johnston, Richard S.; Naumann, Christopher R.; Saunders, Michael D.

2012-01-01

Bile duct cancers are increasing in frequency while being difficult to diagnose. Currently available endoscopic imaging devices used in the biliary tree are low resolution with poor image quality, leading to inadequate evaluation of indeterminate biliary strictures. However, a new ultrathin and flexible cholangioscope system has been successfully demonstrated in a human subject. This mini-cholangioscope system uses a scanning fiber endoscope (SFE) as a forward-imaging guidewire, dimensions of 1.2-mm diameter and 3-m length. Full color video (500-line resolution at 30Hz) is the standard SFE imaging mode using spiral scanning of red, green, and blue laser light at low power. Image-guided operation of the biopsy forceps was demonstrated in healthy human bile ducts with and without saline flushing. The laser-based video imaging can be switched to various modes to enhance tissue markers of disease, such as widefield fluorescence and enhanced spectral imaging. In parallel work, biochemical discrimination of tissue health in pig bile duct has been accomplished using fiberoptic delivery of pulsed UV illumination and time-resolved autofluorescence spectroscopic measurements. Implementation of time-resolved fluorescence spectroscopy for biochemical assessment of the bile duct wall is being done through a secondary endoscopic channel. Preliminary results indicate that adequate SNR levels (> 30 dB) can be achieved through a 50 micron fiber, which could serve as an optical biopsy probe. The SFE is an ideal mini-cholangioscope for integration of both tissue and molecular specific image contrast in the future. This will provide the physician with unprecedented abilities to target biopsy locations and perform endoscopically-guided therapies.

Holmium laser lithotripsy (HoLL) of ureteral calculi

NASA Astrophysics Data System (ADS)

Kuntz, Rainer M.; Lehrich, Karin; Fayad, Amr

2001-05-01

The effectiveness and side effects of ureteroscopic HoLL of ureteral stones should be evaluated. In 63 patients (17 female, 46 males) a total of 75 stones of 3-20 mm diameter were treated with ureteroscopic HoLL. 18.7 percent of stones were located in the proximal third, 24.0 percent in the middle third and 57.3 percent in the distal third of the ureter. HoLL was performed with small diameter semirigid and flexible ureteroscopes, 220 or 365 nm flexible laser fibers and a holmium:YAG laser at a power of 5-15 W (0.5-1.0 J, 10- 15 Hz). 47 of 63 patients (74.6 percent) were immediately free of stones, and 8 others (12.6 percent) lost their residual fragments spontaneously within two weeks. Another 2 patients received additional chmolitholysis for uric acid stone fragments, i.e. 90.5 percent of patients were stone free by one sitting of ureterscopic HoLL. Of the remaining 6 patients (9.5 percent) who still had residual calculi 4 weeks after HoLL, 2 asymptomatic patients refused any additional treatment, 2 patients preferred treatment with ESWL, and 2 patients had a successful second HoLL, thereby raising the success rate of ureteroscopic HoLL to 93.7 percent. 2 patients showed contrast medium extravasation on retrograde ureterograms, due to guide wire perforation. No ureteral stricture occurred. In conclusion, transurethral ureteroscopic HoLL proved to be a safe and successful minimal invasive treatment of ureteral calculi.

Endoscopic features of lymphoid follicles using blue laser imaging (BLI) endoscopy in the colorectum and its association with chronic bowel symptoms

PubMed Central

Takahama, Kazuya; Tahara, Sayumi; Yoshida, Dai; Horiguchi, Noriyuki; Kawamura, Tomohiko; Okubo, Masaaki; Nagasaka, Mitsuo; Nakagawa, Yoshihito; Urano, Makoto; Shibata, Tomoyuki; Tuskamoto, Tetsuya; Ieda, Hiro-o; Kuroda, Makoto; Ohmiya, Naoki

2017-01-01

Background/Aim In the colorectum, lymphoid follicles hyperplasia (LH) is sometimes observed as small, round, yellowish-white nodules. The novel image-enhanced endoscopy system named blue laser imaging (BLI) provides enhanced the contrast of surface vessels using lasers for light illumination. We investigated the endoscopic features of LH observed by using BLI endoscopy and its association with chronic bowel symptoms. Patients/Methods 300 participants undergoing colonoscopy for various indications were enrolled. Entire colorectum was observed by using BLI-bright mode with non-magnification view. LH was defined as well demarcated white nodules. Elevated LH with erythema was distinguished as LH severe. Results LHs were observed more clearly by using BLI-bright mode compared to conventional white light colonoscopy and were also histologically confirmed as intense infiltration of lymphocytes or plasmacytes. LH was observed in 134 subjects (44.6%) and 67 (22.3%) were LH severe. LH was associated younger age (Odds ratio (OR) = 1.05, 95%Confidence Interval (95%CI) = 1.03–1.07, P<0.0001) and chronic bowel symptoms including constipation, hard stools, diarrhea and loose stools (all LH: OR = 4.03, 95%CI = 2.36–6.89, P<0.0001, LH severe: OR = 5.31, 95%CI = 2.64–10.71, P<0.0001). LH severe was closely associated with both constipation associated symptoms (OR = 3.94, 95%CI = 1.79–8.66, P = 0.0007) and diarrhea associated symptoms (OR = 5.22, 95%CI = 2.09–13.05, P = 0.0004). In particular, LH severe in the ascending colon was strongly associated with bowel symptoms (P<0.0001). Conclusion LH, visualized by using BLI endoscopy was associated with bowel symptom, raising the possibility of pathogenic role of this endoscopic finding in the functional lower gastrointestinal disorders. PMID:28763491

Endoscopic root canal treatment.

PubMed

Moshonov, Joshua; Michaeli, Eli; Nahlieli, Oded

2009-10-01

To describe an innovative endoscopic technique for root canal treatment. Root canal treatment was performed on 12 patients (15 teeth), using a newly developed endoscope (Sialotechnology), which combines an endoscope, irrigation, and a surgical microinstrument channel. Endoscopic root canal treatment of all 15 teeth was successful with complete resolution of all symptoms (6-month follow-up). The novel endoscope used in this study accurately identified all microstructures and simplified root canal treatment. The endoscope may be considered for use not only for preoperative observation and diagnosis but also for active endodontic treatment.

Low-cost endoscopic third ventriculostomy simulator with mimetic endoscope.

PubMed

Garling, Richard Justin; Jin, Xin; Yang, Jianzhong; Khasawneh, Ahmad H; Harris, Carolyn Anne

2018-05-11

OBJECTIVE Hydrocephalus affects approximately 1 in 500 people in the US, yet ventricular shunting, the gold standard of treatment, has a nearly 85% failure rate. Endoscopic third ventriculostomy (ETV) is an alternative surgical approach for a specific subset of hydrocephalic patients, but can be limited by the inability of neurosurgical residents to practice prior to patient contact. The goal of this study was to create an affordable ETV model and endoscope for resident training. METHODS Open-source software was used to isolate the skull and brain from the CT and MR images of a 2-year-old boy with hydrocephalus. A 3D printer created the skull and a 3D mold of the brain. A mixture of silicone and silicone tactile mutator was used to cast the brain mold prior to subsequent compression and shearing modulus testing. A mimetic endoscope was then created from basic supplies and a 3D printed frame. A small cohort of neurosurgical residents and attending physicians evaluated the ETV simulator with mimetic endoscope. RESULTS The authors successfully created a mimetic endoscope and ETV simulator. After compression and shearing modulus testing, a silicone/Slacker ratio between 10:6 and 10:7 was found to be similar to that of human brain parenchyma. Eighty-seven percent of participants strongly agreed that the simulator was useful for resident training, and 93% strongly agreed that the simulator helped them understand how to orient themselves with the endoscope. CONCLUSIONS The authors created an affordable (US$123, excluding 3D printer), easy-to-use ETV simulator with endoscope. Previous models have required expensive software and costly operative endoscopes that may not be available to most residents. Instead, this attempt takes advantage of open-source software for the manipulation and fabrication of a patient-specific mold. This model can assist with resident development, allowing them to safely practice use of the endoscope in ETV.

New developments in diagnosis and non-surgical treatment of chronic pancreatitis.

PubMed

Inui, Kazuo; Yoshino, Junji; Miyoshi, Hironao; Yamamoto, Satoshi; Kobayashi, Takashi

2013-12-01

Chronic pancreatitis is progressive and irreversible, leading to digestive and absorptive disorders by destruction of the exocrine pancreas and to diabetes mellitus by destruction of the endocrine pancreas. When complications such as pancreatolithiasis and pseudocyst occur, elevated pancreatic ductal pressure exacerbates pain and induces other complications, worsening the patient's general condition. Combined treatment with extracorporeal shock-wave lithotripsy and endoscopic lithotripsy is a useful, minimally invasive, first-line treatment approach that can preserve pancreatic exocrine function. Pancreatic duct stenosis elevates intraductal pressure and favor both pancreatolithiasis and pseudocyst formation, making effective treatment vitally important. Endoscopic treatment of benign pancreatic duct stenosis stenting frequently decreases pain in chronic pancreatitis. Importantly, stenosis of the main pancreatic duct increases risk of stone recurrence after treatment of pancreatolithiasis. Recently, good results were reported in treating pancreatic duct stricture with a fully covered self-expandable metallic stent, which shows promise for preventing stone recurrence after lithotripsy in patients with pancreatic stricture. Chronic pancreatitis has many complications including pancreatic carcinoma, pancreatic atrophy, and loss of exocrine and endocrine function, as well as frequent recurrence of stones after treatment of pancreatolithiasis. As early treatment of chronic pancreatitis is essential, the new concept of early chronic pancreatitis, including characteristics findings in endoscopic ultrasonograms, is presented. © 2013 Journal of Gastroenterology and Hepatology Foundation and Wiley Publishing Asia Pty Ltd.

Deciding to buy expensive technology. The case of biliary lithotripsy.

PubMed

Weingart, S N

1995-01-01

Acquiring expensive, new medical technology requires an evaluation of the efficacy and effectiveness, safety, profitability, feasibility, and risk of a project in the context of the hospital's social responsibility and institutional strategy. A case study of the decision to bring biliary lithotripsy to Strong Memorial Hospital illustrates how these criteria offer managers a coherent approach to difficult and consequential decisions about acquiring medical technology.

Endoscopic ultrasound

MedlinePlus

... page: //medlineplus.gov/ency/article/007646.htm Endoscopic ultrasound To use the sharing features on this page, please enable JavaScript. Endoscopic ultrasound is a type of imaging test. It is ...

Clinical efficacy, safety, and costs of percutaneous occlusive balloon catheter-assisted ureteroscopic lithotripsy for large impacted proximal ureteral calculi: a prospective, randomized study.

PubMed

Qi, Shiyong; Li, Yanni; Liu, Xu; Zhang, Changwen; Zhang, Hongtuan; Zhang, Zhihong; Xu, Yong

2014-09-01

To evaluate the clinical efficacy, safety, and costs of percutaneous occlusive balloon catheter-assisted ureteroscopic lithotripsy (POBC-URSL) for large impacted proximal ureteral calculi. 156 patients with impacted proximal ureteral stones ≥1.5 cm in size were randomized to ureteroscopic lithotripsy (URSL), POBC-URSL, and percutaneous nephrolithotomy (PNL) group between May 2010 and May 2013. For URSL, the calculi were disintegrated with the assistance of anti-retropulsion devices. POBC-URSL was performed with the assistance of an 8F percutaneous occlusive balloon catheter. PNL was finished with the combination of an ultrasonic and a pneumatic lithotripter. A flexible ureteroscope and a 200 μm laser fiber were used to achieve stone-free status to a large extent for each group. Variables studied were mean operative time, auxiliary procedure, postoperative hospital stay, operation-related complications, stone clearance rate, and treatment costs. The mean lithotripsy time for POBC-URSL was shorter than URSL, but longer than PNL (42.6±8.9 minutes vs 66.7±15.3 minutes vs 28.1±6.3 minutes, p=0.014). The auxiliary procedure rate and postoperative fever rate for POBC-URSL were significantly lower than URSL and comparable to PNL (p<0.01, p=0.034). POBC-URSL was superior to URSL with regard to the stone clearance rate at 3 days postoperatively, and as good as PNL (98.1% vs 75.0% vs 96.2%, p<0.01). The postoperative hospital stay and hematuria rate were lower in POBC-URSL group than PNL group and similar to URSL group (p=0.016, p<0.01). The treatment costs were lowest in POBC-URSL group ($1205.0±$113.9 vs $1731.7±$208.1 vs $2446.4±$166.4, p=0.004). For large impacted proximal ureteral calculi, POBC-URSL was associated with a higher stone clearance rate, fewer complications and costs. POBC-URSL combined the advantages of URSL and PNL.

Efficacy and safety of extracorporeal shock wave lithotripsy for chronic pancreatitis.

PubMed

Vaysse, Thibaut; Boytchev, Isabelle; Antoni, Guillemette; Croix, Damien Sainte; Choury, André Daniel; Laurent, Valérie; Pelletier, Gilles; Buffet, Catherine; Bou-Farah, Rita; Carbonnel, Franck

2016-11-01

There is still uncertainty regarding the efficacy and optimal modalities of extracorporeal shock wave lithotripsy (ESWL) in the treatment of chronic pancreatitis. The aims of the present study were to assess the safety and the efficacy of ESWL, either alone or followed by therapeutic endoscopic retrograde cholangiopancreatography (adjuvant ERCP) and to determine predictive factors of efficacy, in a real-life setting. This study included all consecutive patients who underwent an ESWL in a single University Hospital between 2001 and 2012. The indication for ESWL was obstructive stone(s) of the main pancreatic duct resulting in either painful chronic pancreatitis or recurrent acute pancreatitis. Success was defined by resolution of pain, no analgesic treatment, no acute pancreatitis and no surgical treatment for chronic pancreatitis 6 months after the ESWL. One hundred and forty-six patients were studied; 6/146 (4%) had a complication of ESWL. Among the 132 patients in whom follow-up was completed, 91 (69%) had an adjuvant ERCP. After 6 months of follow-up, 100/132 (76%) patients achieved success. In multivariate analysis, the single significant predictive factor of the success of the ESWL treatment was chronic pain (p = 0.03). Patients who had chronic pain and needed opioid treatment had less chance of success than patients without chronic pain (OR 95%CI 0.31 [0.07-1.14]). We found no difference in the success rates between patients who underwent adjuvant ERCP and those who had ESWL only (p = 0.93). This study shows that the ESWL is a safe and effective treatment for patients with chronic pancreatitis and obstructive stones within the main pancreatic duct. Systematic association with therapeutic ERCP appears to provide no additional benefit and is therefore not recommended.

Treatment of mid- and lower ureteric calculi: extracorporeal shock-wave lithotripsy vs laser ureteroscopy. A comparison of costs, morbidity and effectiveness.

PubMed

Bierkens, A F; Hendrikx, A J; De La Rosette, J J; Stultiens, G N; Beerlage, H P; Arends, A J; Debruyne, F M

1998-01-01

To determine the efficacy and costs of extracorporeal shock-wave lithotripsy (ESWL) compared with ureteroscopy (URS) in the treatment of mid- and lower ureteric calculi. The records of patients treated primarily by ESWL and URS were analysed retrospectively. Treatment with ESWL included 63 patients (42 men and 21 women, mean age 52 years, range 23-78, 19 mid- and 44 lower ureteric calculi). All patients received 4000 shock waves at a mean energy setting of 18.1 kV. URS was used in 105 patients, with a 7.2 F miniscope or the 7.1 F flexible scope. Stones were fragmented with a pulsed-dye laser lithotripter at 504 nm and a power of up to 130 mJ (mean 53 mJ) using a 200 or 320 microns fibre. All ureteroscopies were performed with the patient under general (n = 17) or spinal (n = 87) anaesthesia in a mean treatment duration of 34 min. Stones were located in the mid-ureter in 24 patients and in the lower ureter in 80. The outcome was assessed by stone-free rates, re-treatment rates, time to become stone-free, complication and costs. ESWL for mid- and lower ureteric calculi resulted in a success rate of 90% and 81%, respectively, compared with 96% and 99% for URS. However, patients treated with URS were stone-free within 2 days, whereas patients in the ESWL group required up to 4 months. The best results for ESWL were achieved with stones of < 50 mm2. The costs of URS were higher than those for ESWL. ESWL provides a noninvasive, simple and safe option for the management of mid- and lower ureteric calculi, provided that the stones are < 50 mm2; larger stones are best treated by URS.

Carbon Dioxide Laser Fiber Optics In Endoscopy

NASA Astrophysics Data System (ADS)

Fuller, Terry A.

1982-12-01

Carbon dioxide laser surgery has been limited to a great extent to surgical application on the integument and accessible cavities such as the cervix, vagina, oral cavities, etc. This limitation has been due to the rigid delivery systems available to all carbon dioxide lasers. Articulating arms (series of hollow tubes connected by articulating mirrors) have provided an effective means of delivery of laser energy to the patient as long as the lesion was within the direct line of sight. Even direct line-of-sight applications were restricted to physical dimension of the articulating arm or associated hand probes, manipulators and hollow tubes. The many attempts at providing straight endoscopic systems to the laser only stressed the need for a fiber optic capable of carrying the carbon dioxide laser wavelength. Rectangular and circular hollow metal waveguides, hollow dielectric waveguides have proven ineffective to the stringent requirements of a flexible surgical delivery system. One large diameter (1 cm) fiber optic delivery system, incorporates a toxic thalliumAbased fiber optic material. The device is an effective alternative to an articulating arm for external or conventional laser surgery, but is too large and stiff to use as a flexible endoscopic tool. The author describes the first highly flexible inexpensive series of fiber optic systems suitable for either conventional or endoscopic carbon dioxide laser surgery. One system (IRFLEX 3) has been manufactured by Medlase, Inc. for surgical uses capable of delivering 2000w, 100 mJ pulsed energy and 15w continuous wave. The system diameter is 0.035 inches in diameter. Surgically suitable fibers as small as 120 um have been manufactured. Other fibers (IRFLEX 142,447) have a variety of transmission characteristics, bend radii, etc.

Endoscope field of view measurement.

PubMed

Wang, Quanzeng; Khanicheh, Azadeh; Leiner, Dennis; Shafer, David; Zobel, Jurgen

2017-03-01

The current International Organization for Standardization (ISO) standard (ISO 8600-3: 1997 including Amendment 1: 2003) for determining endoscope field of view (FOV) does not accurately characterize some novel endoscopic technologies such as endoscopes with a close focus distance and capsule endoscopes. We evaluated the endoscope FOV measurement method (the FOV WS method) in the current ISO 8600-3 standard and proposed a new method (the FOV EP method). We compared the two methods by measuring the FOV of 18 models of endoscopes (one device for each model) from seven key international manufacturers. We also estimated the device to device variation of two models of colonoscopes by measuring several hundreds of devices. Our results showed that the FOV EP method was more accurate than the FOV WS method, and could be used for all endoscopes. We also found that the labelled FOV values of many commercial endoscopes are significantly overstated. Our study can help endoscope users understand endoscope FOV and identify a proper method for FOV measurement. This paper can be used as a reference to revise the current endoscope FOV measurement standard.

Endoscope field of view measurement

PubMed Central

Wang, Quanzeng; Khanicheh, Azadeh; Leiner, Dennis; Shafer, David; Zobel, Jurgen

2017-01-01

The current International Organization for Standardization (ISO) standard (ISO 8600-3: 1997 including Amendment 1: 2003) for determining endoscope field of view (FOV) does not accurately characterize some novel endoscopic technologies such as endoscopes with a close focus distance and capsule endoscopes. We evaluated the endoscope FOV measurement method (the FOVWS method) in the current ISO 8600-3 standard and proposed a new method (the FOVEP method). We compared the two methods by measuring the FOV of 18 models of endoscopes (one device for each model) from seven key international manufacturers. We also estimated the device to device variation of two models of colonoscopes by measuring several hundreds of devices. Our results showed that the FOVEP method was more accurate than the FOVWS method, and could be used for all endoscopes. We also found that the labelled FOV values of many commercial endoscopes are significantly overstated. Our study can help endoscope users understand endoscope FOV and identify a proper method for FOV measurement. This paper can be used as a reference to revise the current endoscope FOV measurement standard. PMID:28663840

Future Development of Endoscopic Accessories for Endoscopic Submucosal Dissection

PubMed Central

Jang, Jae-Young

2017-01-01

Endoscopic submucosal dissection (ESD) has recently been accepted as a standard treatment for patients with early gastric cancer (EGC), without lymph node metastases. Given the rise in the number of ESDs being performed, new endoscopic accessories are being developed and existing accessories modified to facilitate the execution of ESD and reduce complication rates. This paper examines the history underlying the development of these new endoscopic accessories and indicates future directions for the development of these accessories. PMID:28609819

Novel instrumentation in urologic surgery: Shock wave lithotripsy

PubMed Central

Semins, Michelle J.; Matlaga, Brian R.

2010-01-01

Extracorporeal shock wave lithotripsy (SWL) was first introduced in 1980 and it rapidly revolutionized the treatment of stone disease. SWL is a non-invasive, outpatient procedure that now accounts for the majority of stone removal procedures. Since the introduction of first generation lithotripter, the Dornier HM3 machine, SWL devices have undergone many modifications secondary to limitations, in efforts to create a more effective and efficient way to treat stones and decrease possible morbidities. Herein, we review the evolution of the technology and advances in the instrumentation over the last three decades. PMID:21116366

New tip design and shock wave pattern of electrohydraulic probes for endoureteral lithotripsy.

PubMed

Vorreuther, R

1993-02-01

A new tip design of a 3.3F electrohydraulic probe for endoureteral lithotripsy was evaluated in comparison to a regular probe. The peak pressure, as well as the slope of the shock front, depend solely on the voltage. Increasing the capacity leads merely to broader pulses. A laser-like short high-pressure pulse has a greater impact on stone disintegration than a corresponding broader low-pressure pulse of the same energy. Using the regular probe, only positive pressures were obtained. Pressure distribution around the regular tip was approximately spherical, whereas the modified probe tip "beamed" the shock wave to a great extent. In addition, a negative-pressure half-cycle was added to the initial positive peak pressure, which resulted in a higher maximal pressure amplitude. The directed shock wave had a greater depth of penetration into a model stone. Thus, the ability of the new probe to destroy harder stones especially should be greater. The trauma to the ureter was reduced when touching the wall tangentially. No difference in the effect of the two probes was seen when placing the probe directly on the mucosa.

Clinical study using novel endoscopic system for measuring size of gastrointestinal lesion

PubMed Central

Oka, Kiyoshi; Seki, Takeshi; Akatsu, Tomohiro; Wakabayashi, Takao; Inui, Kazuo; Yoshino, Junji

2014-01-01

AIM: To verify the performance of a lesion size measurement system through a clinical study. METHODS: Our proposed system, which consists of a conventional endoscope, an optical device, an optical probe, and a personal computer, generates a grid scale to measure the lesion size from an endoscopic image. The width of the grid scale is constantly adjusted according to the distance between the tip of the endoscope and lesion because the lesion size on an endoscopic image changes according to the distance. The shape of the grid scale was corrected to match the distortion of the endoscopic image. The distance was calculated using the amount of laser light reflected from the lesion through an optical probe inserted into the instrument channel of the endoscope. The endoscopist can thus measure the lesion size without contact by comparing the lesion with the size of the grid scale on the endoscopic image. (1) A basic test was performed to verify the relationship between the measurement error eM and the tilt angle of the endoscope; and (2) The sizes of three colon polyps were measured using our system during endoscopy. These sizes were immediately measured by scale after their removal. RESULTS: There was no error at α = 0°. In addition, the values of eM (mean ± SD) were 0.24 ± 0.11 mm (α = 10°), 0.90 ± 0.58 mm (α = 20°) and 2.31 ± 1.41 mm (α = 30°). According to these results, our system has been confirmed to measure accurately when the tilt angle is less than 20°. The measurement error was approximately 1 mm in the clinical study. Therefore, it was concluded that our proposed measurement system was also effective in clinical examinations. CONCLUSION: By combining simple optical equipment with a conventional endoscope, a quick and accurate system for measuring lesion size was established. PMID:24744595

Comparison of tissue injury from focused ultrasonic propulsion of kidney stones versus extracorporeal shock wave lithotripsy.

PubMed

Connors, Bret A; Evan, Andrew P; Blomgren, Philip M; Hsi, Ryan S; Harper, Jonathan D; Sorensen, Mathew D; Wang, Yak-Nam; Simon, Julianna C; Paun, Marla; Starr, Frank; Cunitz, Bryan W; Bailey, Michael R; Lingeman, James E

2014-01-01

Focused ultrasonic propulsion is a new noninvasive technique designed to move kidney stones and stone fragments out of the urinary collecting system. However, to our knowledge the extent of tissue injury associated with this technique is not known. We quantitated the amount of tissue injury produced by focused ultrasonic propulsion under simulated clinical treatment conditions and under conditions of higher power or continuous duty cycles. We compared those results to extracorporeal shock wave lithotripsy injury. A human calcium oxalate monohydrate stone and/or nickel beads were implanted by ureteroscopy in 3 kidneys of live pigs weighing 45 to 55 kg and repositioned using focused ultrasonic propulsion. Additional pig kidneys were exposed to extracorporeal shock wave lithotripsy level pulse intensity or continuous ultrasound exposure 10 minutes in duration using an ultrasound probe transcutaneously or on the kidney. These kidneys were compared to 6 treated with an unmodified Dornier HM3 lithotripter (Dornier Medical Systems, Kennesaw, Georgia) using 2,400 shocks at 120 shock waves per minute and 24 kV. Histological analysis was performed to assess the volume of hemorrhagic tissue injury created by each technique according to the percent of functional renal volume. Extracorporeal shock wave lithotripsy produced a mean ± SEM lesion of 1.56% ± 0.45% of functional renal volume. Ultrasonic propulsion produced no detectable lesion with simulated clinical treatment. A lesion of 0.46% ± 0.37% or 1.15% ± 0.49% of functional renal volume was produced when excessive treatment parameters were used with the ultrasound probe placed on the kidney. Focused ultrasonic propulsion produced no detectable morphological injury to the renal parenchyma when using clinical treatment parameters but produced injury comparable in size to that of extracorporeal shock wave lithotripsy when using excessive treatment parameters. Copyright © 2014 American Urological Association Education and

Flexible endoscopes: structure and function: the endoscopic retrograde cholangiopancreatography elevator system.

PubMed

Holland, Pat; Shoop, Nancy M

2002-01-01

Flexible endoscopes are complex medical instruments that are easily damaged. In order to maintain the flexible endoscope in optimum working condition, the user must have a thorough understanding of the structure and function of the instrument. This is the fourth in a series of articles presenting an in-depth look at the care and handling of the flexible endoscope. The first three articles discussed the air-water system, the suction channel system, and the mechanical system. This article will focus specifically on the endoscopic retrograde cholangiopancreatography elevator system.

Minimally invasive management with holmium laser in total urinary tract calculi.

PubMed

Zhang, Xiao; Yu, Jianjun; Yang, Ranxing

2013-05-01

The purpose of this article was to study the management of total urinary tract calculi using holmium laser minimally invasive techniques. It is rare for patients to present kidney stones, ureteral stones, and bladder stones simultaneously, and their treatment is considered to be complicated and difficult, specifically by minimally invasive techniques. We collected seven cases of total urinary tract calculi from May 2007 to September 2012. Three cases were unilateral, and the others were bilateral. All of the cases presented calculus in the bladder, ureter, and kidney, which were secondary to the long-term indwelling double J stent or lower urinary obstruction. Extracorporeal shock-wave lithotripsy (SWL) was administered first, followed by the operation. For patients with bilateral calculi, at one stage, ureteroscopic lithotripsy (URL) with holmium laser was performed in all four cases to remove the bladder and bilateral ureter stones. Then, all patients underwent percutaneous nephrolithotomy (PCNL) with holmium procedures to address the bilateral kidney and upper ureter stones at the second stage. The indwelling double J stents were removed at the same time. For the patients with unilateral calculi, we performed a single operation, but it was conducted using the same treatment sequence as the bilateral procedure. The related symptoms in all cases disappeared after the operation. Re-examination showed that the stones were nearly dissolved and that renal function was recovered. URL with holmium laser for the bladder and ureters combined with PCNL to dissolve kidney and upper ureteral stones could be the ideal choice for the treatment of total urinary tract calculi.

Surgical Lasers In Gynecology

NASA Astrophysics Data System (ADS)

Schellhas, Helmut F.; Barnes, Alfonso E.

1982-12-01

Multipurpose surgical CO2 lasers marketed in the USA have been developed to be applicable to a variety of surgical procedures in many surgical fields. They are all suited for endoscopic surgical procedures and can be fitted to all standard surgical microscopes. They all can adjust the focal length of the laser beam to the different standard focal lengths of the surgical microscope which for instance in laryngoscopy is 400 mm and in colposcopy 300 mm. One laser instrument can even change the spot size in a given focal distance which is very advantageous for some microsurgical procedures (Merrimack Laboratories 820). All multipurpose surgical CO2 laser systems provide a multi-articulated surgical arm for free-hand surgery. The surgical arms are cumbersome to use but they are adapted to the surgeons needs with ingenuity. The practicality of the multi-articulated surgical arms depends mostly on the distance of the handpiece from the surgical console which now is also overbridged by the laser tube in most surgical laser system. The spot size of the beam is variable in most handpieces by interchangeable lenses which modify the focal distance of the beam and the power density. Another common feature in all systems is a coaxial He-Ne pilot light which provides a red spot which unfortunately becomes invisible in a bleeding surgical field. Most surgical laser systems have a spacial mode of TEM 00 which is essential for incisional surgery. The continuous mode of beam delivery is used for incisional surgery and also for most endoscopic procedures.

Robot-assisted endoscope guidance versus manual endoscope guidance in functional endonasal sinus surgery (FESS).

PubMed

Eichhorn, Klaus Wolfgang; Westphal, Ralf; Rilk, Markus; Last, Carsten; Bootz, Friedrich; Wahl, Friedrich; Jakob, Mark; Send, Thorsten

2017-10-01

Having one hand occupied with the endoscope is the major disadvantage for the surgeon when it comes to functional endoscopic sinus surgery (FESS). Only the other hand is free to use the surgical instruments. Tiredness or frequent instrument changes can thus lead to shaky endoscopic images. We collected the pose data (position and orientation) of the rigid 0° endoscope and all the instruments used in 16 FESS procedures with manual endoscope guidance as well as robot-assisted endoscope guidance. In combination with the DICOM CT data, we tracked the endoscope poses and workspaces using self-developed tracking markers. All surgeries were performed once with the robot and once with the surgeon holding the endoscope. Looking at the durations required, we observed a decrease in the operating time because one surgeon doing all the procedures and so a learning curve occurred what we expected. The visual inspection of the specimens showed no damages to any of the structures outside the paranasal sinuses. Robot-assisted endoscope guidance in sinus surgery is possible. Further CT data, however, are desirable for the surgical analysis of a tracker-based navigation within the anatomic borders. Our marker-based tracking of the endoscope as well as the instruments makes an automated endoscope guidance feasible. On the subjective side, we see that RASS brings a relief for the surgeon.

Endoscopic papillary large balloon dilation for the removal of bile duct stones.

PubMed

Kim, Jin Hong; Yang, Min Jae; Hwang, Jae Chul; Yoo, Byung Moo

2013-12-14

Endoscopic papillary large balloon dilation (EPLBD) with endoscopic sphincterotomy (EST) has been widely used as the alternative to EST along with endoscopic mechanical lithotripsy (EML) for the removal of large or difficult bile duct stones. Furthermore, EPLBD without EST was recently introduced as its simplified alternative technique. Thus, we systematically searched PubMed, Medline, the Cochrane Library and EMBASE, and analyzed all gathered data of EPLBD with and without EST, respectively, by using a single standardized definition, reviewing relevant literatures, published between 2003 and June 2013, where it was performed with large-diameter balloons (12-20 mm). The outcomes, including the initial success rate, the rate of needs for EML, and the overall success rate, and adverse events were assessed in each and compared between both of two procedures: "EPLBD with EST" and "EPLBD without EST". A total of 2511 procedures from 30 published articles were included in EPLBD with EST, while a total of 413 procedures from 3 published articles were included in EPLBD without EST. In the results of outcomes, the overall success rate was 96.5% in EPLBD with EST and 97.2% in EPLBD without EST, showing no significant difference between both of them. The initial success rate (84.0% vs 76.2%, P < 0.001) and the success rate of EPLBD without EML (83.2% vs 76.7%, P = 0.001) was significantly higher, while the rate of use of EML was significantly lower (14.1% vs 21.6%, P < 0.001), in EPLBD with EST. The rate of overall adverse events, pancreatitis, bleeding, perforation, other adverse events, surgery for adverse events, and fatal adverse events were 8.3%, 2.4%, 3.6%, 0.6%, 1.7%, 0.2% and 0.2% in EPLBD with EST and 7.0%, 3.9%, 1.9%, 0.5%, 0.7%, 0% and 0% in EPLBD without EST, respectively, showing no significant difference between both of them. In conclusion, recent accumulated results of EPLBD with or even without EST suggest that it is a safe and effective procedure for the

The Clinical Accuracy of Endoscopic Ultrasonography and White Light Imaging in Gastric Endoscopic Submucosal Dissection

PubMed Central

Park, Soon Hong; Sung, Sang Hun; Lee, Seung Jun; Jung, Min Kyu; Kim, Sung Kook

2012-01-01

Purpose Gastric mucosal neoplastic lesions should have characteristic endoscopic features for successful endoscopic submucosal dissection. Materials and Methods Out of the 1,010 endoscopic submucosal dissection, we enrolled 62 patients that had the procedure cancelled. Retrospectively, whether the reasons for cancelling the endoscopic submucosal dissection were consistent with the indications for an endoscopic submucosal dissection were assessed by analyzing the clinical outcomes of the patients that had the surgery. Results The cases were divided into two groups; the under-diagnosed group (30 cases; unable to perform an endoscopic submucosal dissection) and the over-diagnosed group (32 cases; unnecessary to perform an endoscopic submucosal dissection), according to the second endoscopic findings, compared with the index conventional white light image. There were six cases in the under-diagnosed group with advanced gastric cancer on the second conventional white light image endoscopy, 17 cases with submucosal invasion on endoscopic ultrasonography findings, 5 cases with a size greater than 3 cm and ulcer, 1 case with diffuse infiltrative endoscopic features, and 1 case with lymph node involvement on computed tomography. A total of 25 patients underwent a gastrectomy to remove a gastric adenocarcinoma. The overall accuracy of the decision to cancel the endoscopic submucosal dissection was 40% (10/25) in the subgroup that had the surgery. Conclusions The accuracy of the decision to cancel the endoscopic submucosal dissection, after conventional white light image and endoscopic ultrasonography, was low in this study. Other diagnostic options are needed to arrive at an accurate decision on whether to perform a gastric endoscopic submucosal dissection. PMID:22792522

Endoscopic injection therapy.

PubMed

Kim, Sang Woon; Lee, Yong Seung; Han, Sang Won

2017-06-01

Since the U.S. Food and Drug Administration approved dextranomer/hyaluronic acid copolymer (Deflux) for the treatment of vesicoureteral reflux, endoscopic injection therapy using Deflux has become a popular alternative to open surgery and continuous antibiotic prophylaxis. Endoscopic correction with Deflux is minimally invasive, well tolerated, and provides cure rates approaching those of open surgery (i.e., approximately 80% in several studies). However, in recent years a less stringent approach to evaluating urinary tract infections (UTIs) and concerns about long-term efficacy and complications associated with endoscopic injection have limited the use of this therapy. In addition, there is little evidence supporting the efficacy of endoscopic injection therapy in preventing UTIs and vesicoureteral reflux-related renal scarring. In this report, we reviewed the current literature regarding endoscopic injection therapy and provided an updated overview of this topic.

The efficacy and safety of the flexible fiber CO2 laser delivery system in the endoscopic management of pediatric airway problems: Our long term experience.

PubMed

Lee, Gi Soo; Irace, Alexandra; Rahbar, Reza

2017-06-01

To report the use of flexible fiber CO2 laser in the endoscopic management of pediatric airway cases. A retrospective review was conducted of patients who underwent CO2 laser-assisted airway procedures between September 2007 and January 2014 at a tertiary pediatric hospital. Sixty-eight patients underwent 80 procedures utilizing flexible fiber CO2 laser. Procedures included supraglottoplasty (n = 32), laryngeal cleft repair (type I [n = 10], type II [n = 7], type III [n = 6]), suprastomal granuloma excision (n = 6), cordotomy (n = 4), laryngeal neurofibroma excision (n = 4), laryngeal granulomatous mass excision (n = 1), subglottic stenosis excision (n = 6), division of glottic web (n = 2), subglottic cyst excision (n = 1), and supraglottic biopsy (n = 1). Ages ranged from 8 days to 21 years (median 11 months). No intraoperative or postoperative complications related to the use of laser were noted. The flexible fiber CO2 laser can be safely and effectively used to address a variety of pediatric airway lesions. Previously, the use of CO2 laser in minimally invasive airway surgery has been limited due to the articulating arm carrier, absence of a hand piece, and the direct line-of sight view required. The fiber allows the cutting beam to be directed at the site of the lesion and bypasses limitations posed by other laser systems. Copyright © 2017 Elsevier B.V. All rights reserved.

PubMed Central

Farneti, P.; Cantore, S.; Macrì, G.; Chuchueva, N.; Cuffaro, L.; Pasquini, L.; Puxeddu, R.

2017-01-01

SUMMARY Obstructive sialadenitis is the most common non-neoplastic disease of the salivary glands, and sialendoscopy is increasingly used in both diagnosis and treatment, associated in selected cases with endoscopic laser lithotripsy. Sialendoscopy is also used for combined minimally invasive external and endoscopic approaches in patients with larger and proximal stones that would require excessively long laser procedures. The present paper reports on the technical experience from the Ear, Nose and Throat Unit of the Sant'Orsola-Malpighi Hospital of Bologna, and from the Department of Otorhinolaryngology of the University Hospital of Cagliari, Italy, including the retrospective analysis of the endoscopic and endoscopic assisted procedures performed on 48 patients (26 females and 22 males; median age 45.3; range 8-83 years) treated for chronic obstructive sialadenitis at the University Hospital of Cagliari from November 2010 to April 2016. The results from the Sant'Orsola-Malpighi Hospital of Bologna have been previously published. The technical aspects of sialendoscopy are carefully described. The retrospective analysis of the University Hospital of Cagliari shows that the disease was unilateral in 40 patients and bilateral in 8; a total of 56 major salivary glands were treated (22 submandibular glands and 34 parotids). Five patients underwent bilateral sialendoscopy for juvenile recurrent parotitis. 10 patients were treated for non-lithiasic obstructive disease. In 33 patients (68.75%) the obstruction was caused by salivary stones (bilateral parotid lithiasis in 1 case). Only 8 patients needed a sialectomy (5 submandibular glands and 3 parotids). The conservative approach to obstructive sialadenitis is feasible and can be performed either purely endoscopically or in a combined modality, with a high percentage of success. The procedure must be performed with dedicated instrumentation by a skilled surgeon after proper training since minor to major complications can

Proximal design for a multimodality endoscope with multiphoton microscopy, optical coherence microscopy and visual modalities

NASA Astrophysics Data System (ADS)

Kiekens, Kelli C.; Talarico, Olivia; Barton, Jennifer K.

2018-02-01

A multimodality endoscope system has been designed for early detection of ovarian cancer. Multiple illumination and detection systems must be integrated in a compact, stable, transportable configuration to meet the requirements of a clinical setting. The proximal configuration presented here supports visible light navigation with a large field of view and low resolution, high resolution multiphoton microscopy (MPM), and high resolution optical coherence microscopy (OCM). All modalities are integrated into a single optical system in the endoscope. The system requires two light sources: a green laser for visible light navigation and a compact fiber based femtosecond laser for MPM and OCM. Using an inline wavelength division multiplexer, the two sources are combined into a single mode fiber. To accomplish OCM, a fiber coupler is used to separate the femtosecond laser into a reference arm and signal arm. The reflected reference arm and the signal from the sample are interfered and wavelength separated by a reflection grating and detected using a linear array. The MPM signal is collimated and goes through a series of filters to separate the 2nd and 3rd harmonics as well as twophoton excitation florescence (2PEF) and 3PEF. Each signal is independently detected on a photo multiplier tube and amplified. The visible light is collected by multiple high numerical aperture fibers at the endoscope tip which are bundled into one SMA adapter at the proximal end and connected to a photodetector. This integrated system design is compact, efficient and meets both optical and mechanical requirements for clinical applications.

Extracorporeal shockwave lithotripsy, endourology and open surgery: the management and follow-up of 200 patients with urinary calculi.

PubMed Central

Webb, D. R.; McNicholas, T. A.; Whitfield, H. N.; Wickham, J. E.

1985-01-01

The management and follow up of 200 consecutive patients with renal and ureteric calculi are presented. The primary treatment of 185 (92.5%) was by extracorporeal shockwave lithotripsy (ESWL), of whom three (1.6)%) with large calculi underwent percutaneous nephrolithotripsy (PCNL) prior to ESWL as a planned combined procedure. Twelve (6%) were treated by PCNL or ureterorenoscopy (URS) as their definitive treatment and three (1.5%) by conventional open renal and ureteric surgery. The average in-patient stay was 3.8 days and most returned to normal activity within one day of discharge. Of the 185 patients 102 (55%) required no analgesia after treatment by ESWL, 29 (15.6%) required parenteral analgesia and the rest were comfortable with oral non-narcotic medication. Thirty (16%) required auxillary treatment by percutaneous nephrostomy (PCN), PCNL and URS following ESWL for obstructive complications from stone particles. Two required further ESWL and one PCNL at three months for large fragments. Overall, open surgery was required for only 1% of renal calculi and 13% of ureteric stones. These results are consistant with the extensive West German experience confirming that most urinary calculi are now best managed by ESWL and endoscopic techniques. Where these facilities are available open surgery should only be necessary for less than 5% of upper urinary tract stones. PMID:4073760

Fast calibration of electromagnetically tracked oblique-viewing rigid endoscopes.

PubMed

Liu, Xinyang; Rice, Christina E; Shekhar, Raj

2017-10-01

The oblique-viewing (i.e., angled) rigid endoscope is a commonly used tool in conventional endoscopic surgeries. The relative rotation between its two moveable parts, the telescope and the camera head, creates a rotation offset between the actual and the projection of an object in the camera image. A calibration method tailored to compensate such offset is needed. We developed a fast calibration method for oblique-viewing rigid endoscopes suitable for clinical use. In contrast to prior approaches based on optical tracking, we used electromagnetic (EM) tracking as the external tracking hardware to improve compactness and practicality. Two EM sensors were mounted on the telescope and the camera head, respectively, with considerations to minimize EM tracking errors. Single-image calibration was incorporated into the method, and a sterilizable plate, laser-marked with the calibration pattern, was also developed. Furthermore, we proposed a general algorithm to estimate the rotation center in the camera image. Formulas for updating the camera matrix in terms of clockwise and counterclockwise rotations were also developed. The proposed calibration method was validated using a conventional [Formula: see text], 5-mm laparoscope. Freehand calibrations were performed using the proposed method, and the calibration time averaged 2 min and 8 s. The calibration accuracy was evaluated in a simulated clinical setting with several surgical tools present in the magnetic field of EM tracking. The root-mean-square re-projection error averaged 4.9 pixel (range 2.4-8.5 pixel, with image resolution of [Formula: see text] for rotation angles ranged from [Formula: see text] to [Formula: see text]. We developed a method for fast and accurate calibration of oblique-viewing rigid endoscopes. The method was also designed to be performed in the operating room and will therefore support clinical translation of many emerging endoscopic computer-assisted surgical systems.

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.

Systematic Review of Endoscopic Obliteration Techniques for Managing Congenital Piriform Fossa Sinus Tracts in Children.

PubMed

Lachance, Sophie; Chadha, Neil K

2016-02-01

Piriform fossa sinus tracts (PFSTs) are a recognized cause of recurrent deep neck infections in the pediatric population. Conventional management has historically required open resection, but over recent years minimally invasive endoscopic approaches to obliterate the pharyngeal opening of the sinus have been performed in many centers. However, there is a lack of clear evidence regarding the success rate and safety of these approaches. To determine the success rate of endoscopic management of PFST through a systematic review of the existing literature. MEDLINE (1964-2014) and bibliographies of identified papers. Two authors independently reviewed 170 abstracts and identified relevant studies for full-text review. Data were independently extracted from those studies, and the Oxford Centre for Evidence-Based Medicine guidelines were used to classify the level of evidence. Thirteen studies met the inclusion criteria, comprising a total of 84 patients. All included studies were evidence level 4 (case series). Various methods of obliterating the PFST were described: electrocautery (n = 39), laser (n = 19), trichloroacetic acid (n = 19), silver nitrate (n = 4), combination of silver nitrate and laser (n = 2), and fibrin glue (n = 1). The success rate for endoscopic management of PFST was 89.3% overall (90.5% in primary cases and 85.7% in revision cases). The only adverse event reported was temporary vocal cord immobility in 2.4% (n = 2) of cases. Endoscopic management of pediatric PFST appears to be safe and effective, as a primary option and for revision after open surgery. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2015.

Observations of the collapses and rebounds of millimeter-sized lithotripsy bubbles

PubMed Central

Kreider, Wayne; Crum, Lawrence A.; Bailey, Michael R.; Sapozhnikov, Oleg A.

2011-01-01

Bubbles excited by lithotripter shock waves undergo a prolonged growth followed by an inertial collapse and rebounds. In addition to the relevance for clinical lithotripsy treatments, such bubbles can be used to study the mechanics of inertial collapses. In particular, both phase change and diffusion among vapor and noncondensable gas molecules inside the bubble are known to alter the collapse dynamics of individual bubbles. Accordingly, the role of heat and mass transport during inertial collapses is explored by experimentally observing the collapses and rebounds of lithotripsy bubbles for water temperatures ranging from 20 to 60 °C and dissolved gas concentrations from 10 to 85% of saturation. Bubble responses were characterized through high-speed photography and acoustic measurements that identified the timing of individual bubble collapses. Maximum bubble diameters before and after collapse were estimated and the corresponding ratio of volumes was used to estimate the fraction of energy retained by the bubble through collapse. The rebounds demonstrated statistically significant dependencies on both dissolved gas concentration and temperature. In many observations, liquid jets indicating asymmetric bubble collapses were visible. Bubble rebounds were sensitive to these asymmetries primarily for water conditions corresponding to the most dissipative collapses. PMID:22088027

Probe-based confocal laser endomicroscopy in the margin delineation of early gastric cancer for endoscopic submucosal dissection.

PubMed

Park, Jun Chul; Park, Yehyun; Kim, Hyun Ki; Jo, Jeong-Hyeon; Park, Chan Hyuk; Kim, Eun Hye; Jung, Da Hyun; Chung, Hyunsoo; Shin, Sung Kwan; Lee, Sang Kil; Lee, Yong Chan

2017-05-01

We evaluated probe-based confocal laser endomicroscopy (pCLE) in the margin delineation of early gastric cancer (EGC) for endoscopic submucosal dissection in comparison with white-light imaging with chromoendoscopy (CE). We conducted a prospective, randomized controlled study from November 2013 to October 2014 in a tertiary referral hospital. A total of 101 patients scheduled for endoscopic submucosal dissection due to differentiated EGC were randomized into pCLE and CE groups (pCLE 51, CE 50). Markings were made by electrocautery at the proximal and distal tumor margins, as determined by either pCLE or CE. The distance from the marking to the tumor margin was measured in the resected specimen histopathologically and was compared between the two groups by a linear mixed model. Among 104 lesions, 80 lesions with 149 markings (pCLE 68, CE 81) were analyzed after excluding undifferentiated EGCs (n = 8) and unidentifiable markings (n = 13). Although the complete resection rate showed no difference between the groups (94.6% vs 93.2%, P = 1.000), the median distance from the marking to the margin was shorter in the pCLE group (1.3 vs 1.8 mm, P = 0.525) and the proportion of the distance <1 mm was higher (43.9% vs 27.6%, P = 0.023) in the pCLE group. Finally, subgroup analysis with superficial flat lesions (18 lesions, 31 marking dots) showed a significantly decreased distance in the pCLE group (0.5 vs 3.1 mm, P = 0.007). Among EGCs with superficial flat morphology, in which the accurate evaluation of lateral extent is difficult with CE, pCLE would be useful for more precise margin delineation. © 2016 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.

Linked color imaging application for improving the endoscopic diagnosis accuracy: a pilot study.

PubMed

Sun, Xiaotian; Dong, Tenghui; Bi, Yiliang; Min, Min; Shen, Wei; Xu, Yang; Liu, Yan

2016-09-19

Endoscopy has been widely used in diagnosing gastrointestinal mucosal lesions. However, there are still lack of objective endoscopic criteria. Linked color imaging (LCI) is newly developed endoscopic technique which enhances color contrast. Thus, we investigated the clinical application of LCI and further analyzed pixel brightness for RGB color model. All the lesions were observed by white light endoscopy (WLE), LCI and blue laser imaging (BLI). Matlab software was used to calculate pixel brightness for red (R), green (G) and blue color (B). Of the endoscopic images for lesions, LCI had significantly higher R compared with BLI but higher G compared with WLE (all P < 0.05). R/(G + B) was significantly different among 3 techniques and qualified as a composite LCI marker. Our correlation analysis of endoscopic diagnosis with pathology revealed that LCI was quite consistent with pathological diagnosis (P = 0.000) and the color could predict certain kinds of lesions. ROC curve demonstrated at the cutoff of R/(G+B) = 0.646, the area under curve was 0.646, and the sensitivity and specificity was 0.514 and 0.773. Taken together, LCI could improve efficiency and accuracy of diagnosing gastrointestinal mucosal lesions and benefit target biopsy. R/(G + B) based on pixel brightness may be introduced as a objective criterion for evaluating endoscopic images.

Instrumentation For The Surgical Application Of The Nd:YAG Laser

NASA Astrophysics Data System (ADS)

Frank, F.; Bailer, P.; Beck, O.; Bowering, R.; Hofstetter, A.

1984-03-01

The Nd:YAG laser has become a coagulation instrument, which has found acceptance in interdisciplinary surgery. The main contributors are its highly efficient coagulation capability in interaction with tissue and the fact that the Nd:YAG laser beam can be transmitted by means of a simple quartz-glass fiber. Appropriate systems and instruments for transmission and operation have been developed for the various applications in neurosurgery, pulmology, gastroenterology, urology, gynaecology and dermatology. Operation methods in open and endoscopic surgery under use of several hand held devices and flexible as well as rigid endoscopes are being demonstrated by clinical examples of application.

Extracorporeal shock wave lithotripsy for pancreatic and large common bile duct stones

PubMed Central

Tandan, Manu; Reddy, D Nageshwar

2011-01-01

Extraction of large pancreatic and common bile duct (CBD) calculi has always challenged the therapeutic endoscopist. Extracorporeal shockwave lithotripsy (ESWL) is an excellent tool for patients with large pancreatic and CBD calculi that are not amenable to routine endotherapy. Pancreatic calculi in the head and body are targeted by ESWL, with an aim to fragment them to < 3 mm diameter so that they can be extracted by subsequent endoscopic retrograde cholangiopancreatography (ERCP). In our experience, complete clearance of the pancreatic duct was achieved in 76% and partial clearance in 17% of 1006 patients. Short-term pain relief with reduction in the number of analgesics ingested was seen in 84% of these patients. For large CBD calculi, a nasobiliary tube is placed to help target the calculi, as well as bathe the calculi in saline - a simple maneuver which helps to facilitate fragmentation. The aim is to fragment calculi to < 5 mm size and clear the same during ERCP. Complete clearance of the CBD was achieved in 84.4% of and partial clearance in 12.3% of 283 patients. More than 90% of the patients with pancreatic and biliary calculi needed three or fewer sessions of ESWL with 5000 shocks being delivered at each session. The use of epidural anesthesia helped in reducing patient movement. This, together with the better focus achieved with newer third-generation lithotripters, prevents collateral tissue damage and minimizes the complications. Complications in our experience with nearly 1300 patients were minimal, and no extension of hospital stay was required. Similar rates of clearance of pancreatic and biliary calculi with minimal adverse effects have been reported from the centers where ESWL is performed regularly. In view of its high efficiency, non-invasive nature and low complication rates, ESWL can be offered as the first-line therapy for selected patients with large pancreatic and CBD calculi. PMID:22110261

Sparse aperture endoscope

DOEpatents

Fitch, J.P.

1999-07-06

An endoscope is disclosed which reduces the volume needed by the imaging part, maintains resolution of a wide diameter optical system, while increasing tool access, and allows stereographic or interferometric processing for depth and perspective information/visualization. Because the endoscope decreases the volume consumed by imaging optics such allows a larger fraction of the volume to be used for non-imaging tools, which allows smaller incisions in surgical and diagnostic medical applications thus produces less trauma to the patient or allows access to smaller volumes than is possible with larger instruments. The endoscope utilizes fiber optic light pipes in an outer layer for illumination, a multi-pupil imaging system in an inner annulus, and an access channel for other tools in the center. The endoscope is amenable to implementation as a flexible scope, and thus increases it's utility. Because the endoscope uses a multi-aperture pupil, it can also be utilized as an optical array, allowing stereographic and interferometric processing. 7 figs.

Sparse aperture endoscope

DOEpatents

Fitch, Joseph P.

1999-07-06

An endoscope which reduces the volume needed by the imaging part thereof, maintains resolution of a wide diameter optical system, while increasing tool access, and allows stereographic or interferometric processing for depth and perspective information/visualization. Because the endoscope decreases the volume consumed by imaging optics such allows a larger fraction of the volume to be used for non-imaging tools, which allows smaller incisions in surgical and diagnostic medical applications thus produces less trauma to the patient or allows access to smaller volumes than is possible with larger instruments. The endoscope utilizes fiber optic light pipes in an outer layer for illumination, a multi-pupil imaging system in an inner annulus, and an access channel for other tools in the center. The endoscope is amenable to implementation as a flexible scope, and thus increases the utility thereof. Because the endoscope uses a multi-aperture pupil, it can also be utilized as an optical array, allowing stereographic and interferometric processing.

Towards endoscopic ultrafast laser microsurgery of vocal folds

NASA Astrophysics Data System (ADS)

Hoy, Christopher L.; Everett, W. Neil; Yildirim, Murat; Kobler, James; Zeitels, Steven M.; Ben-Yakar, Adela

2012-03-01

Vocal fold scarring is a predominant cause of voice disorders yet lacks a reliable treatment method. The injection of soft biomaterials to improve mechanical compliance of the vocal folds has emerged as a promising treatment. Here, we study the use of precise femtosecond laser microsurgery to ablate subsurface voids, with a goal of eventually creating a plane in dense subepithelial scar tissue into which biomaterials can be injected for their improved localization. Specifically, we demonstrate the ablation of small subepithelial voids in porcine vocal fold tissue up to 120 µm below the surface such that larger voids in the active area of vocal fold mucosa (~3×10 mm2) can eventually be ablated in about 3 min. We use sub-µJ, 776-nm pulses from a compact femtosecond fiber laser system operating at a 500-kHz repetition rate. The use of relatively high repetition rates, with a small number of overlapping pulses, is critical to achieving ablation in a very short time while still avoiding significant heat deposition. Additionally, we use the same laser for nonlinear optical imaging to provide visual feedback of tissue structure and to confirm successful ablation. The ablation parameters, including pulse duration, pulse energy, spot size, and scanning speed, are comparable to the specifications in our recently developed miniaturized femtosecond laser surgery probes, illustrating the feasibility of developing an ultrafast laser surgical instrument.

Endoscopic low-coherence topography measurement for upper airways and hollow samples

NASA Astrophysics Data System (ADS)

Delacrétaz, Yves; Shaffer, Etienne; Pavillon, Nicolas; Kühn, Jonas; Lang, Florian; Depeursinge, Christian

2010-11-01

To evaluate the severity of airway pathologies, quantitative dimensioning of airways is of utmost importance. Endoscopic vision gives a projective image and thus no true scaling information can be directly deduced from it. In this article, an approach based on an interferometric setup, a low-coherence laser source and a standard rigid endoscope is presented, and applied to hollow samples measurements. More generally, the use of the low-coherence interferometric setup detailed here could be extended to any other endoscopy-related field of interest, e.g., gastroscopy, arthroscopy and other medical or industrial applications where tri-dimensional topology is required. The setup design with a multiple fibers illumination system is presented. Demonstration of the method ability to operate on biological samples is assessed through measurements on ex vivo pig bronchi.

Application of a 980-nanometer diode laser in neuroendoscopy: a case series.

PubMed

Reis, Rodolfo Casimiro; Teixeira, Manoel Jacobsen; Mancini, Marilia Wellichan; Almeida-Lopes, Luciana; de Oliveira, Matheus Fernandes; Pinto, Fernando Campos Gomes

2016-02-01

Ventricular neuroendoscopy represents an important advance in the treatment of hydrocephalus. High-power (surgical) Nd:YAG laser and low-level laser therapy (using 685-nm-wavelength diode laser) have been used in conjunction with neuroendoscopy with favorable results. This study evaluated the use of surgical 980-nm-wavelength diode laser for the neuroendoscopic treatment of ventricular diseases. Nine patients underwent a neuroendoscopic procedure with 980-nm diode laser. Complications and follow-up were recorded. Three in-hospital postoperative complications were recorded (1 intraventricular hemorrhage and 2 meningitis cases). The remaining 6 patients had symptom improvement after endoscopic surgery and were discharged from the hospital within 24-48 hours after surgery. Patients were followed for an average of 14 months: 1 patient developed meningitis and another died suddenly at home. The other patients did well and were asymptomatic until the last follow-up consultation. The 980-nm diode laser is considered an important therapeutic tool for endoscopic neurological surgeries. This study showed its application in different ventricular diseases.

Diagnostic and therapeutic direct peroral cholangioscopy using an intraductal anchoring balloon.

PubMed

Parsi, Mansour A; Stevens, Tyler; Vargo, John J

2012-08-14

To report our experience using a recently introduced anchoring balloon for diagnostic and therapeutic direct peroral cholangioscopy (DPOC). Consecutive patients referred for diagnostic or therapeutic peroral cholangioscopy were evaluated in a prospective cohort study. The patients underwent DPOC using an intraductal anchoring balloon, which was recently introduced to allow consistent access to the biliary tree with an ultraslim upper endoscope. The device was later voluntarily withdrawn from the market by the manufacturer. Fourteen patients underwent DPOC using the anchoring balloon. Biliary access with an ultraslim upper endoscope was accomplished in all 14 patients. In 12 (86%) patients, ductal access required sphincteroplasty with a 10-mm dilating balloon. Intraductal placement of the ultraslim upper endoscope allowed satisfactory visualization of the biliary mucosa to the level of the confluence of the right and left hepatic ducts in 13 of 14 patients (93%). Therapeutic interventions by DPOC were successfully completed in all five attempted cases (intraductal biopsy in one and DPOC guided laser lithotripsy in four). Adverse events occurred in a patient on immunosuppressive therapy who developed an intrahepatic biloma at the site of the anchoring balloon. This required hospitalization and antibiotics. Repeat endoscopic retrograde cholangiopancreatography 8 wk after the index procedure showed resolution of the biloma. Use of this anchoring balloon allowed consistent access to the biliary tree for performance of diagnostic and therapeutic DPOC distal to the biliary bifurcation.

Fabrication of a chirped artificial compound eye for endoscopic imaging fiber bundle by dose-modulated laser lithography and subsequent thermal reflow

NASA Astrophysics Data System (ADS)

Deng, Shengfeng; Lyu, Jinke; Sun, Hongda; Cui, Xiaobin; Wang, Tun; Lu, Miao

2015-03-01

A chirped artificial compound eye on a curved surface was fabricated using an optical resin and then mounted on the end of an endoscopic imaging fiber bundle. The focal length of each lenslet on the curved surface was variable to realize a flat focal plane, which matched the planar end surface of the fiber bundle. The variation of the focal length was obtained by using a photoresist mold formed by dose-modulated laser lithography and subsequent thermal reflow. The imaging performance of the fiber bundle was characterized by coupling with a coaxial light microscope, and the result demonstrated a larger field of view and better imaging quality than that of an artificial compound eye with a uniform focal length. Accordingly, this technology has potential application in stereoscopic endoscopy.

Renal staghorn calculosis: our experience with the percutaneous treatment with or without extracorporeal shock wave lithotripsy.

PubMed

Bianchi, G; Malossini, G; Beltrami, P; Mobilio, G; Giusti; Caluccio, G

1998-04-01

In this paper we report our results in the treatment of renal staghorn stones by percutaneous lithotripsy (PCNL) with or without extracorporeal shock wave lithotripsy (ESWL). Over a period of 5 years, 244 patients with renal calculosis were treated by PCNL in our Department. Seventy-four of these were cases of renal staghorn calculosis: 44 presented a partial staghorn stone and in 30 cases the stone formation completely occupied the pyelocalieal cavity. We performed first a PCNL via a rigid nephroscope. Stones were crushed using an ultrasonic lithotrite; an electrohydraulic probe was used when the calculus was resistant to ultrasound. The patients were submitted to one or more percutaneous treatments followed by extracorporeal lithotripsy to complete the operation, when required. The patients were divided into two groups according to the type of stone: the first group comprised 59 patients with a partial or complete simple staghorn stone and the second comprised 15 patients with a complete complex staghorn stone. Complete resolution was achieved in 55 of the 59 cases (93.2%) in the first group and in 9 of the 15 cases (60%) in the second. We had no complications. Our experience confirms that PCNL is the elective treatment for partial and complete staghorn stones and ESWL in these types of stones must be utilized only as ancillary treatment for residual fragments.

The Steris Reliance EPS endoscope processing system: a new automated endoscope reprocessing technology.

PubMed

2007-01-01

In this Evaluation, we examine whether the Steris Reliance EPS--a flexible endoscope reprocessing system that was recently introduced to the U.S. market--offers meaningful advantages over "traditional" automated endoscope reprocessors (AERs). Most AERs on the market function similarly to one another. The Reliance EPS, however, includes some unique features that distinguish it from other AERs. For example, it incorporates a "boot" technology for loading the endoscopes into the unit without requiring a lot of endoscope-specific connectors, and it dispenses the germicide used to disinfect the endoscopes from a single-use container. This Evaluation looks at whether the unique features of this model make it a better choice than traditional AERs for reprocessing flexible endoscopes. Our study focuses on whether the Reliance EPS is any more likely to be used correctly-thereby reducing the likelihood that an endoscope will be reprocessed inadequately-and whether the unit possesses any design flaws that could lead to reprocessing failures. We detail the unit's advantages and disadvantages compared with other AERs, and we describe what current users have to say. Our conclusions will help facilities determine whether to select the Reliance EPS.

Endoscopic Skull Base Surgery

PubMed Central

Senior, Brent A

2008-01-01

Endoscopic skull base surgery has undergone rapid advancement in the past decade moving from pituitary surgery to suprasellar lesions and now to a myriad of lesions extending from the cribriform plate to C2 and laterally out to the infratemporal fossa and petrous apex. Evolution of several technological advances as well as advances in understanding of endoscopic anatomy and the development of surgical techniques both in resection and reconstruction have fostered this capability. Management of benign disease via endoscopic methods is largely accepted now but more data is needed before the controversy on the role of endoscopic management of malignant disease is decided. Continued advances in surgical technique, navigation systems, endoscopic imaging technology, and robotics assure continued brisk evolution in this expanding field. PMID:19434274

Mitomycin C and the endoscopic treatment of laryngotracheal stenosis: are two applications better than one?

PubMed

Smith, Marshall E; Elstad, Mark

2009-02-01

Endoscopic treatment of laryngotracheal stenosis by airway dilation, despite short-term improvement, is often associated with long-term relapse. Mitomycin-C (MMC) inhibits fibroblast proliferation and synthesis of extracellular matrix proteins, and thereby modulates wound healing and scarring. MMC application at the time of endoscopic dilation and laser surgery has been suggested to improve outcomes, but this has not been studied in a rigorous manner. This study examines the hypothesis that two topical applications of MMC given 3-6 weeks apart will result in decreased scarring/restenosis of the airway, when compared to a single topical application. A randomized, prospective, double-blind, placebo-controlled clinical trial. Twenty-six patients with laryngotracheal stenosis due to idiopathic subglottic stenosis, postintubation stenosis, or Wegener's granulomatosis entered a protocol to receive three endoscopic CO(2) laser and dilation procedures over a 3-month interval. At the first procedure, after radial CO(2) laser incision and airway dilation, all patients received topical application of MMC (0.5 mg/mL) to the airway lesion. One month later, a second endoscopic incision and dilation was performed and the patients were randomized to either a second application of mitomycin-C or to application of saline placebo. A third dilation procedure was performed 2 months later, without MMC application. Patients were followed for up to 5 years for relapse of airway stenosis with clinical symptoms sufficient to require a subsequent procedure. The relapse rates at 1, 3, and 5 years were 7%, 36%, and 69% for patients treated with two applications of MMC compared to 33%, 58%, and 70% for patients treated with one application of MMC. The median interval to relapse was 3.8 years in the two-application group, compared with 2.4 years in the one-application group. This prospective randomized double-blind placebo-controlled trial suggests that, in the endoscopic management of

The comparation of effects and security of double-J stent retention and ureteroscopy lithotripsy in the treatment of symptomatic ureteral calculi during pregnancy.

PubMed

Tan, Shu-Tao; Chen, Xiaonan; Sun, Ming; Wu, Bin

2018-06-01

To describe the efficacy of double-J stent retention and ureteroscopy lithotripsy, we performed a study to evaluate the management of symptomatic ureteral calculi during pregnancy. From January 2005 and June 2015, 53 pregnant women with symptomatic ureteral calculi were admitted and treated in our hospital. According to the treatment techniques, there were divided into two groups: double-J stent retention group (30 cases) and ureteroscopy lithotripsy group (23 cases). We collected the characteristics and treatment outcome of the patients. Double-J stent retention was performed on 30 patients. And the stents were successfully inserted in 25 patients (83.3%). 4 cases got complication in double-J group (16%). The mean operating time, medical cost and hospitalization time of double-J group were 20.6 min, 1632 yuan and 1.3 days. Ureteroscopy lithotripsy was performed on 23 patients. 20 patients were operated successfully (87.0%). 2 cases got complication in ureteroscopy group (10.0%). The mean operating time, medical cost and hospitalization time of ureteroscopy group were 41.5 min, 2792 yuan and 6.0 days. In summary, both double-J stent retention and ureteroscopy lithotripsy are effective and safe in the managation of ureteral calculi during pregnancy. Copyright © 2018 Elsevier B.V. All rights reserved.

Endoscopic Devices for Obesity.

PubMed

Sampath, Kartik; Dinani, Amreen M; Rothstein, Richard I

2016-06-01

The obesity epidemic, recognized by the World Health Organization in 1997, refers to the rising incidence of obesity worldwide. Lifestyle modification and pharmacotherapy are often ineffective long-term solutions; bariatric surgery remains the gold standard for long-term obesity weight loss. Despite the reported benefits, it has been estimated that only 1% of obese patients will undergo surgery. Endoscopic treatment for obesity represents a potential cost-effective, accessible, minimally invasive procedure that can function as a bridge or alternative intervention to bariatric surgery. We review the current endoscopic bariatric devices including space occupying devices, endoscopic gastroplasty, aspiration technology, post-bariatric surgery endoscopic revision, and obesity-related NOTES procedures. Given the diverse devices already FDA approved and in development, we discuss the future directions of endoscopic therapies for obesity.

Development of Endoscopic Diagnosis and Treatment for Chronic Unilateral Hematuria: 35 Years Experience.

PubMed

Tanimoto, Ryuta; Kumon, Hiromi; Bagley, Demetrius H

2017-04-01

Chronic unilateral hematuria (CUH) is also called lateralizing essential hematuria, benign essential hematuria, and benign lateralizing hematuria, which was defined as intermittent or continuous gross hematuria that cannot be diagnosed with standard radiology and hematology studies, together with unilateral bloody efflux by cystoscopy. CUH is rare, but sometimes confused with malignancy or life-threatening hemorrhage. Therefore, it can cause considerable anxiety to not only patients but also urologists. For this study, we summarized articles about endoscopic diagnosis and treatment of CUH, and discussed the development of endourology for CUH. We searched articles related to CUH that were indexed in the PubMed database and published in English. Key terms used were "unilateral," "lateralizing," "chronic," "benign," and "idiopathic" hematuria. We found 15 pertinent articles reporting CUH. Endoscopically, CUH can be classified into three categories: discrete lesion, diffuse lesion, or no (unidentified) lesion. Currently, endoscopic techniques for CUH are similar to the techniques for upper tract urothelial carcinoma, using semi-rigid and flexible ureteroscopes with diathermy fulguration or laser ablation for treatment. The overall success rate of endoscopic treatment for CUH, defined as resolution of gross hematuria after treatment, was 93% (190/205). The recurrence rate, defined as recurrent gross hematuria after treatment, was 10% (19/189). Advancements in endoscopic devices and techniques have enabled more accurate and less invasive diagnosis and treatment of CUH. Once CUH is defined, flexible ureteroscopy is the diagnostic and therapeutic technique of choice.

Patient Response to Endoscopic Therapy for Gastroesophageal Varices Based on Endoscopic Ultrasound Findings.

PubMed

Tseng, Yujen; Ma, Lili; Luo, Tiancheng; Zeng, Xiaoqing; Li, Feng; Li, Na; Wei, Yichao; Chen, Shiyao

2018-04-27

Gastroesophageal variceal hemorrhage is a common complication of portal hypertension. Endoscopic therapy is currently recommended for preventing gastroesophageal variceal rebleed. However, the rate of variceal rebleed and its associated mortality remain concerning. This study is aimed at differentiating patient response to endoscopic therapy based on endoscopic ultrasound (EUS) findings. One-hundred seventy patients previously treated with repeat endoscopic therapy for secondary prophylaxis were enrolled and classified into two groups based on treatment response. Prior to consolidation therapy, all patients received an EUS examination to observe for extraluminal phenomena. All available follow-up endoscopic examination records were retrieved to validate study results. Of the 170 subjects, 106 were poor responders, while 64 were good responders. The presence of para-gastric, gastric perforating, and esophageal perforating veins was associated with poor patient response (p＜0.001). The odds ratio for para-gastric veins was 5.374. Follow-up endoscopic findings for poor responders with incomplete variceal obliteration was closely correlated with the presence of para-gastric veins (p=0.002). The presence of para-gastric veins is a characteristic of poor response to endoscopic therapy for treating gastroesophageal varices. Early identification of this subgroup necessitates a change in course of treatment to improve overall patient outcome.

Autonomous locomotion of capsule endoscope in gastrointestinal tract.

PubMed

Yang, Sungwook; Park, Kitae; Kim, Jinseok; Kim, Tae Song; Cho, Il-Joo; Yoon, Eui-Sung

2011-01-01

Autonomous locomotion in gastrointestinal (GI) tracts is achieved with a paddling-based capsule endoscope. For this, a miniaturized encoder module was developed utilizing a MEMS fabrication technology to monitor the position of paddles. The integrated encoder module yielded the high resolution of 0.0025 mm in the linear motion of the paddles. In addition, a PID control method was implemented on a DSP to control the stroke of the paddles accurately. As a result, the average accuracy and the standard deviation were measured to be 0.037 mm and 0.025 mm by a laser position sensor for the repetitive measurements. The locomotive performance was evaluated via ex-vivo tests according to various strokes in paddling. In an in-vivo experiment with a living pig, the locomotion speed was improved by 58% compared with the previous control method relying on a given timer value for reciprocation of the paddles. Finally, the integrated encoder module and the control system allow consistent paddling during locomotion even under loads in GI tract. It provides the autonomous locomotion without intervention in monitoring and controlling the capsule endoscope.

Functional results of endoscopic laser surgery in advanced head and neck tumors

NASA Astrophysics Data System (ADS)

Sadick, Haneen; Baker-Schreyer, Antonio; Bergler, Wolfgang; Maurer, Joachim; Hoermann, Karl

1998-01-01

Functional results following lasersurgery of minor laryngeal carcinomas were very encouraging. The indication for lasersurgical intervention was then extended to larger carcinomas of the larynx and hypopharynx. The purpose of this study was to assess vocal function and swallowing ability after endoscopic lasersurgery and to compare the results with conventional surgical procedures. From January 1994 to December 1996, 72 patients with advanced squamous cell carcinoma of the larynx and hypopharynx were examined prospectively. The patients underwent endoscopic lasersurgery instead of laryngopharyngectomy. The voice quality was evaluated pre- and postoperatively by subjective assessment, registration of voice parameters and sonegraphic classification. The swallowing ability was judged according to individual scores. The necessity of tracheostomy and nasogastric tube were registered and the duration of hospitalization was documented. The results showed that laryngeal phonation and swallowing ability were significantly better 12 months after lasersurgery compared to the preoperative findings whereas the recurrence rate was similar or even better after conventional pharyngolaryngectomy. Lasersurgery as an alternative surgical procedure to laryngectomy enables patients to retain a sufficient voice function and swallowing ability.

endoscope-i: an innovation in mobile endoscopic technology transforming the delivery of patient care in otolaryngology.

PubMed

Mistry, N; Coulson, C; George, A

2017-11-01

Digital and mobile device technology in healthcare is a growing market. The introduction of the endoscope-i, the world's first endoscopic mobile imaging system, allows the acquisition of high definition images of the ear, nose and throat (ENT). The system combines the e-i Pro camera app with a bespoke engineered endoscope-i adaptor which fits securely onto the iPhone or iPod touch. Endoscopic examination forms a salient aspect of the ENT work-up. The endoscope-i therefore provides a mobile and compact alternative to the existing bulky endoscopic systems currently in use which often restrict the clinician to the clinic setting. Areas covered: This article gives a detailed overview of the endoscope-i system together with its applications. A review and comparison of alternative devices on the market offering smartphone adapted endoscopic viewing systems is also presented. Expert commentary: The endoscope-i fulfils unmet needs by providing a compact, highly portable, simple to use endoscopic viewing system which is cost-effective and which makes use of smartphone technology most clinicians have in their pocket. The system allows real-time feedback to the patient and has the potential to transform the way that healthcare is delivered in ENT as well as having applications further afield.

Improving patient and user safety during endoscopic investigation of the pancreatic and biliary ducts

NASA Astrophysics Data System (ADS)

Chandler, John E.; Melville, C. David; Lee, Cameron M.; Saunders, Michael D.; Burkhardt, Matthew R.; Seibel, Eric J.

2011-03-01

Endoscopic investigation of the main pancreatic duct and biliary ducts is called endoscopic retrograde cholangiopancreatography (ERCP), and carries a risk of pancreatitis for the patient. During ERCP, a metal guidewire is inserted into the pancreatobiliary duct from a side-viewing large endoscope within the duodenum. To verify correct placement of the ERCP guidewire, an injection of radiopaque dye is required for fluoroscopic imaging, which exposes the patient and clinical team to x-ray radiation. A safer and more effective means to access the pancreatobiliary system can use direct optical imaging, although the endoscope diameter and stiffness will be significantly larger than a guidewire's. To quantify this invasiveness before human testing, a synthetic force-sensing pancreas was fabricated and attached to an ERCP training model. The invasiveness of a new, 1.7-mm diameter, steerable scanning fiber endoscope (SFE) was compared to the standard ERCP guidewire of 0.89-mm (0.035") diameter that is not steerable. Although twice as large and significantly stiffer than the ERCP guidewire, the SFE generated lower or significantly less average force during insertion at all 4 sensor locations (P<0.05) within the main pancreatic duct. Therefore, the addition of steering and forward visualization at the tip of the endoscope reduced the invasiveness of the in vitro ERCP procedure. Since fluoroscopy is not required, risks associated with dye injection and x-ray exposure can be eliminated when using direct optical visualization. Finally, the SFE provides wide-field high resolution imaging for image-guided interventions, laser-based fluorescence biomarker imaging, and spot spectral analysis for future optical biopsy.

A novel endoscopic fluorescent band ligation method for tumor localization.

PubMed

Hyun, Jong Hee; Kim, Seok-Ki; Kim, Kwang Gi; Kim, Hong Rae; Lee, Hyun Min; Park, Sunup; Kim, Sung Chun; Choi, Yongdoo; Sohn, Dae Kyung

2016-10-01

Accurate tumor localization is essential for minimally invasive surgery. This study describes the development of a novel endoscopic fluorescent band ligation method for the rapid and accurate identification of tumor sites during surgery. The method utilized a fluorescent rubber band, made of indocyanine green (ICG) and a liquid rubber solution mixture, as well as a near-infrared fluorescence laparoscopic system with a dual light source using a high-powered light-emitting diode (LED) and a 785-nm laser diode. The fluorescent rubber bands were endoscopically placed on the mucosae of porcine stomachs and colons. During subsequent conventional laparoscopic stomach and colon surgery, the fluorescent bands were assayed using the near-infrared fluorescence laparoscopy system. The locations of the fluorescent clips were clearly identified on the fluorescence images in real time. The system was able to distinguish the two or three bands marked on the mucosal surfaces of the stomach and colon. Resection margins around the fluorescent bands were sufficient in the resected specimens obtained during stomach and colon surgery. These novel endoscopic fluorescent bands could be rapidly and accurately localized during stomach and colon surgery. Use of these bands may make possible the excision of exact target sites during minimally invasive gastrointestinal surgery.

Endoscopic management of colorectal adenomas.

PubMed

Meier, Benjamin; Caca, Karel; Fischer, Andreas; Schmidt, Arthur

2017-01-01

Colorectal adenomas are well known precursors of invasive adenocarcinoma. Colonoscopy is the gold standard for adenoma detection. Colonoscopy is far more than a diagnostic tool, as it allows effective treatment of colorectal adenomas. Endoscopic resection of colorectal adenomas has been shown to reduce the incidence and mortality of colorectal cancer. Difficult resection techniques are available, such as endoscopic mucosal resection, endoscopic submucosal dissection and endoscopic full-thickness resection. This review aims to provide an overview of the different endoscopic resection techniques and their indications, and summarizes the current recommendations in the recently published guideline of the European Society of Gastrointestinal Endoscopy.

Endoscopic management of colorectal adenomas

PubMed Central

Meier, Benjamin; Caca, Karel; Fischer, Andreas; Schmidt, Arthur

2017-01-01

Colorectal adenomas are well known precursors of invasive adenocarcinoma. Colonoscopy is the gold standard for adenoma detection. Colonoscopy is far more than a diagnostic tool, as it allows effective treatment of colorectal adenomas. Endoscopic resection of colorectal adenomas has been shown to reduce the incidence and mortality of colorectal cancer. Difficult resection techniques are available, such as endoscopic mucosal resection, endoscopic submucosal dissection and endoscopic full-thickness resection. This review aims to provide an overview of the different endoscopic resection techniques and their indications, and summarizes the current recommendations in the recently published guideline of the European Society of Gastrointestinal Endoscopy. PMID:29118553

New endoscopic and cytologic tools for cancer surveillance in the digestive tract

PubMed Central

Brentnall, Teresa A.; Dominitz, Jason A.

2009-01-01

Synopsis Cancer surveillance is an increasing part of everyday practice in gastrointestinal endoscopy due to the identification of high risk groups from genetic and biomarker testing, genealogic and epidemiologic studies, and the increasing number of cancer survivors. An efficient surveillance program requires a cost-effective means for image-guided cancer detection and biopsy. A laser-based tethered-capsule endoscope with enhanced spectral imaging is introduced for unsedated surveillance of the lower esophagus. An ultrathin version of this same endoscope technology provides a 1.2-mm guidewire with imaging capability and cannula-style tools are proposed for image-guided biopsy. Advanced 3D cell visualization techniques are described for increasing the sensitivity of early cancer diagnosis from hematoxylin-stained cells sampled from the pancreatic and biliary ducts. PMID:19423026

Endoscopic treatments for portal hypertension.

PubMed

Lo, Gin-Ho

2018-02-01

Acute esophageal variceal hemorrhage is a dreaded complication of portal hypertension. Its management has evolved rapidly in recent years. Endoscopic therapy is often employed to arrest bleeding varices as well as to prevent early rebleeding. The combination of vasoconstrictor and endoscopic therapy is superior to vasoconstrictor or endoscopic therapy alone for control of acute esophageal variceal hemorrhage. After control of acute variceal bleeding, combination of banding ligation and beta-blockers is generally recommended to prevent variceal rebleeding. To prevent the catastrophic event of acute variceal bleeding, endoscopic banding ligation is an important tool in the prophylaxis of first bleeding. Endoscopic obturation with cyanoacrylate is usually utilized to arrest acute gastric variceal hemorrhage as well as to prevent rebleeding. It can be concluded that endoscopic therapies play a pivotal role in management of portal hypertensive bleeding.

Foot-controlled robotic-enabled endoscope holder for endoscopic sinus surgery: A cadaveric feasibility study.

PubMed

Chan, Jason Y K; Leung, Iris; Navarro-Alarcon, David; Lin, Weiyang; Li, Peng; Lee, Dennis L Y; Liu, Yun-hui; Tong, Michael C F

2016-03-01

To evaluate the feasibility of a unique prototype foot-controlled robotic-enabled endoscope holder (FREE) in functional endoscopic sinus surgery. Cadaveric study. Using human cadavers, we investigated the feasibility, advantages, and disadvantages of the robotic endoscope holder in performing endoscopic sinus surgery with two hands in five cadaver heads, mimicking a single nostril three-handed technique. The FREE robot is relatively easy to use. Setup was quick, taking less than 3 minutes from docking the robot at the head of the bed to visualizing the middle meatus. The unit is also relatively small, takes up little space, and currently has four degrees of freedom. The learning curve for using the foot control was short. The use of both hands was not hindered by the presence of the endoscope in the nasal cavity. The tremor filtration also aided in the smooth movement of the endoscope, with minimal collisions. The FREE endoscope holder in an ex-vivo cadaver test corroborated the feasibility of the robotic prototype, which allows for a two-handed approach to surgery equal to a single nostril three-handed technique without the holder that may reduce operating time. Further studies will be needed to evaluate its safety profile and use in other areas of endoscopic surgery. NA. Laryngoscope, 126:566-569, 2016. © 2015 The American Laryngological, Rhinological and Otological Society, Inc.

Principles of endoscopic ear surgery.

PubMed

Tarabichi, Muaaz; Kapadia, Mustafa

2016-10-01

The aim of this review is to study the rationale, limitations, techniques, and long-term outcomes of endoscopic ear surgery. The article discusses the advantages of endoscopic ear surgery in treating cholesteatoma and how the hidden sites like facial recess, sinus tympani, and anterior epitympanum are easily accessed using the endoscope. Transcanal endoscopic approach allows minimally invasive removal of cholesteatoma with results that compare well to traditional postauricular tympanomastoidectomy.

Accuracy of radiological features for predicting extracorporeal shock wave lithotripsy success for treatment of kidney calculi.

PubMed

Arshadi, Hamid; Dianat, Seyed Saied; Ganjehei, Leila

2009-01-01

Our aim was to assess the accuracy of radiological characteristics observed by the urologist in estimating the success rate of extracorporeal shock wave lithotripsy (SWL) in patients with kidney calculi. Patients with kidney calculi sized 10 mm to 15 mm who underwent SWL in our center were enrolled. One urologist estimated the success chance of SWL based on plain abdominal radiography. Accordingly, the patients were categorized into 2 groups with more than 75% chance of fragmentation (group 1) and with 50% to 75% estimated chance of fragmentation (group 2). Factors used for estimation included calculus shape, homogeneity, and density as compared with the adjacent 12th rib. The estimations were compared with the resulted stone-free rate after a 3-month follow-up. A total of 137 patients were studied, of whom, 92 (67.2%) were categorized in group 1 and 45 (32.8%) in group 2, before the lithotripsy. Successful treatment was recorded in 101 patients (73.7%). Eighty-five patients with favorable estimated chance of successful lithotripsy (92.4%) had successful SWL, and 29 with less favorable estimate (64.4%) did not have successful fragmentation following 2 sessions of SWL (P < .001). The sensitivity and specificity of radiological parameters for prediction of treatment success were 84.2% and 80.6%, respectively. We found that certain radiographic features of urinary calculi such as calculus density, as compared with the adjacent bone, and calculus shape could have predictive impression for the success rate of SWL.

Novel and safer endoscopic cholecystectomy using only a flexible endoscope via single port

PubMed Central

Mori, Hirohito; Kobayashi, Nobuya; Kobara, Hideki; Nishiyama, Noriko; Fujihara, Shintaro; Chiyo, Taiga; Ayaki, Maki; Nagase, Takashi; Masaki, Tsutomu

2016-01-01

AIM: To apply the laparoscopic and endoscopic cooperative surgery concept, we investigated whether endoscopic cholecystectomy could be performed more safely and rapidly via only 1 port or not. METHODS: Two dogs (11 and 13-mo-old female Beagle) were used in this study. Only 1 blunt port was created, and a flexible endoscope with a tip attachment was inserted between the fundus of gallbladder and liver. After local injection of saline to the gallbladder bed, resection of the gallbladder bed from the liver was performed. After complete resection of the gallbladder bed, the gallbladder was pulled up to resect its neck using the Ring-shaped thread technique. The neck of the gallbladder was cut using scissor forceps. Resected gallbladder was retrieved using endoscopic net forceps via a port. RESULTS: The operation times from general anesthetizing with sevoflurane to finishing the closure of the blunt port site were about 50 min and 60 min respectively. The resection times of gallbladder bed were about 15 min and 13 min respectively without liver injury and bleeding at all. Feed were given just after next day of operation, and they had a good appetite. Two dogs are in good health now and no complications for 1 mo after endoscopic cholecystectomy using only a flexible endoscope via one port. CONCLUSION: We are sure of great feasibility of endoscopic cholecystectomy via single port for human. PMID:27053847

Endoscopic Evacuation of Subdural Collections.

PubMed

Boyaci, Suat; Gumustas, Oguzhan Guven; Korkmaz, Serdar; Aksoy, Kaya

2016-01-01

Intraoperative use of the endoscope is a hot topic in neurosurgery and it gives broader visualization of critical and hardlyreached areas. Endoscope-assisted surgical approach to chronic subdural haematoma (SDH) is a minimally invasive technique and may give an expansion to the regular method of burr-hole haematoma drainage. Endoscope-assisted haematoma drainage with mini-craniotomy was performed over a 24-month period, and prospectively collected data is reviewed. A total of 10 procedures (8 patients) were performed using the endoscopeassisted technique. Four of them were chronic SDH and six were subacute SDH. Procedures were extended 20 minutes in average because of endoscopic intervention. There was no extra-morbidity through the study as a consequence of endoscopic assessment. Endoscope-assisted techniques can make the operation safe in selected circumstances with improved intraoperative visualization. It may likewise take into consideration the identification and destruction of neo-membranes, septums and solid clots. In addition, the source of bleeding can be easily coagulated. The endoscope-assisted techniques, with all of these features, can alter the pre- and intra-operative decision-making for selected patients.

21 CFR 876.1500 - Endoscope and accessories.

Code of Federal Regulations, 2013 CFR

2013-04-01

... within this generic type of device include cleaning accessories for endoscopes, photographic accessories for endoscopes, nonpowered anoscopes, binolcular attachments for endoscopes, pocket battery boxes... endoscope, smoke removal tube, rechargeable battery box, pocket battery box, bite block for endoscope, and...

21 CFR 876.1500 - Endoscope and accessories.

Code of Federal Regulations, 2011 CFR

2011-04-01

... within this generic type of device include cleaning accessories for endoscopes, photographic accessories for endoscopes, nonpowered anoscopes, binolcular attachments for endoscopes, pocket battery boxes... endoscope, smoke removal tube, rechargeable battery box, pocket battery box, bite block for endoscope, and...

21 CFR 876.1500 - Endoscope and accessories.

Code of Federal Regulations, 2012 CFR

2012-04-01

... within this generic type of device include cleaning accessories for endoscopes, photographic accessories for endoscopes, nonpowered anoscopes, binolcular attachments for endoscopes, pocket battery boxes... endoscope, smoke removal tube, rechargeable battery box, pocket battery box, bite block for endoscope, and...

21 CFR 876.1500 - Endoscope and accessories.

Code of Federal Regulations, 2010 CFR

2010-04-01

... within this generic type of device include cleaning accessories for endoscopes, photographic accessories for endoscopes, nonpowered anoscopes, binolcular attachments for endoscopes, pocket battery boxes... endoscope, smoke removal tube, rechargeable battery box, pocket battery box, bite block for endoscope, and...

21 CFR 876.1500 - Endoscope and accessories.

Code of Federal Regulations, 2014 CFR

2014-04-01

... within this generic type of device include cleaning accessories for endoscopes, photographic accessories for endoscopes, nonpowered anoscopes, binolcular attachments for endoscopes, pocket battery boxes... endoscope, smoke removal tube, rechargeable battery box, pocket battery box, bite block for endoscope, and...

Laser application in neurosurgery

PubMed Central

Belykh, Evgenii; Yagmurlu, Kaan; Martirosyan, Nikolay L.; Lei, Ting; Izadyyazdanabadi, Mohammadhassan; Malik, Kashif M.; Byvaltsev, Vadim A.; Nakaji, Peter; Preul, Mark C.

2017-01-01

Background: Technological innovations based on light amplification created by stimulated emission of radiation (LASER) have been used extensively in the field of neurosurgery. Methods: We reviewed the medical literature to identify current laser-based technological applications for surgical, diagnostic, and therapeutic uses in neurosurgery. Results: Surgical applications of laser technology reported in the literature include percutaneous laser ablation of brain tissue, the use of surgical lasers in open and endoscopic cranial surgeries, laser-assisted microanastomosis, and photodynamic therapy for brain tumors. Laser systems are also used for intervertebral disk degeneration treatment, therapeutic applications of laser energy for transcranial laser therapy and nerve regeneration, and novel diagnostic laser-based technologies (e.g., laser scanning endomicroscopy and Raman spectroscopy) that are used for interrogation of pathological tissue. Conclusion: Despite controversy over the use of lasers for treatment, the surgical application of lasers for minimally invasive procedures shows promising results and merits further investigation. Laser-based microscopy imaging devices have been developed and miniaturized to be used intraoperatively for rapid pathological diagnosis. The multitude of ways that lasers are used in neurosurgery and in related neuroclinical situations is a testament to the technological advancements and practicality of laser science. PMID:29204309

Laser-induced fluorescence for the detection of esophageal and skin cancer

NASA Astrophysics Data System (ADS)

Vo-Dinh, Tuan; Panjehpour, Masoud; Overholt, Bergein F.; Julius, Clark E.; Overholt, Suzanne; Phan, Mary N.

2003-07-01

Laser-induced fluorescence (LIF) is used for in-vivo cancer diagnosis of the esophagus and skin cancer. For esophageal measurements a fiberoptic probe inserted through an endoscope was used. Autofluorescence of normal and malignant tissues were measured directly on patient skin without requiring an endoscope. Measurement of the fluorescence signal from the tissue was performed using laser excitation at 410 nm. The methodology was applied to differentiate normal and malignant tumors of the esophagus and malignant skin lesions. The results of this LIF approach were compared with histopathology results of the biopsy samples and indicated excellent agreement in the classification of normal and malignant tumors for the samples investigated.

Endoscopic submucosal dissection for locally recurrent colorectal lesions after previous endoscopic mucosal resection.

PubMed

Zhou, Pinghong; Yao, Liqing; Qin, Xinyu; Xu, Meidong; Zhong, Yunshi; Chen, Weifeng

2009-02-01

The objective of this study was to determine the efficacy and safety of endoscopic submucosal dissection for locally recurrent colorectal cancer after previous endoscopic mucosal resection. A total of 16 patients with locally recurrent colorectal lesions were enrolled. A needle knife, an insulated-tip knife and a hook knife were used to resect the lesion along the submucosa. The rate of the curative resection, procedure time, and incidence of complications were evaluated. Of 16 lesions, 15 were completely resected with endoscopic submucosal dissection, yielding an en bloc resection rate of 93.8 percent. Histologic examination confirmed that lateral and basal margins were cancer-free in 14 patients (87.5 percent). The average procedure time was 87.2 +/- 60.7 minutes. None of the patients had immediate or delayed bleeding during or after endoscopic submucosal dissection. Perforation in one patient (6.3 percent) was the only complication and was managed conservatively. The mean follow-up period was 15.5 +/- 6.8 months; none of the patients experienced lesion residue or recurrence. Endoscopic submucosal dissection appears to be effective for locally recurrent colorectal cancer after previous endoscopic mucosal resection, making it possible to resect whole lesions and provide precise histologic information.

Water content contribution in calculus phantom ablation during Q-switched Tm:YAG laser lithotripsy.

PubMed

Zhang, Jian J; Rajabhandharaks, Danop; Xuan, Jason Rongwei; Wang, Hui; Chia, Ray W J; Hasenberg, Tom; Kang, Hyun Wook

2015-01-01

Q-switched (QS) Tm:YAG laser ablation mechanisms on urinary calculi are still unclear to researchers. Here, dependence of water content in calculus phantom on calculus ablation performance was investigated. White gypsum cement was used as a calculus phantom model. The calculus phantoms were ablated by a total 3-J laser pulse exposure (20 mJ, 100 Hz, 1.5 s) and contact mode with N=15 sample size. Ablation volume was obtained on average 0.079, 0.122, and 0.391  mm3 in dry calculus in air, wet calculus in air, and wet calculus in-water groups, respectively. There were three proposed ablation mechanisms that could explain the effect of water content in calculus phantom on calculus ablation performance, including shock wave due to laser pulse injection and bubble collapse, spallation, and microexplosion. Increased absorption coefficient of wet calculus can cause stronger spallation process compared with that caused by dry calculus; as a result, higher calculus ablation was observed in both wet calculus in air and wet calculus in water. The test result also indicates that the shock waves generated by short laser pulse under the in-water condition have great impact on the ablation volume by Tm:YAG QS laser.

Endoscopic management of sinonasal hemangiopericytoma.

PubMed

Tessema, Belachew; Eloy, Jean Anderson; Folbe, Adam J; Anstead, Amy S; Mirani, Neena M; Jourdy, Deya N; Joudy, Deya N; Ruiz, Jose W; Casiano, Roy R

2012-03-01

Sinonasal hemangiopericytomas (SNHPCs) are rare perivascular tumors with low-grade malignant potential. Traditionally, these tumors have been treated with open approaches such as lateral rhinotomy, Caldwell-Luc, or transfacial approaches. Increased experience with endoscopic management of benign and malignant sinonasal tumors has led to a shift in management of SNHPC. The authors present their experience in the largest series of patients with SNHPC managed endoscopically. Case series at a tertiary care medical center. A retrospective chart review of all patients undergoing endoscopic management of SNHPC at the University of Miami between 1999 and 2008 was conducted. All endoscopic resections were performed with curative intent. Twelve patients with the diagnosis of SNHPC were treated endoscopically. Mean age was 62.5 years (range, 51-83 years). There were 6 men and 6 women. The mean follow-up was 41 months (range, 15-91 months). Seven (58.3%) presented with nasal obstruction, whereas 4 (41.6%) had epistaxis as their initial presenting symptom. Preoperative angiography or embolization was not performed in any case. Mean estimated blood loss was 630 mL (range, 100-1500 mL). Six patients underwent endonasal endoscopic anterior skull base resection; 4 had complete endoscopic resection all with negative margins. None underwent postoperative adjuvant treatment. No recurrence or metastatic disease was observed in this patient population. Endoscopic management of SNHPC is a feasible approach and did not compromise outcomes in this experience. In this series, familiarity with advance endoscopic sinus surgery was necessary to manage these patients. Postoperative adjuvant therapy was not necessary in this cohort.

Pulsed laser-induced liquid jet: evolution from shock/bubble interaction to neurosurgical application

NASA Astrophysics Data System (ADS)

Nakagawa, A.; Kumabe, T.; Ogawa, Y.; Hirano, T.; Kawaguchi, T.; Ohtani, K.; Nakano, T.; Sato, C.; Yamada, M.; Washio, T.; Arafune, T.; Teppei, T.; Atsushi, K.; Satomi, S.; Takayama, K.; Tominaga, T.

2017-01-01

The high-speed liquid (water) jet has distinctive characteristics in surgical applications, such as tissue dissection without thermal damage and small blood vessel preservation, that make it advantageous over more conventional instruments. The continuous pressurized jet has been used since the first medical application of water jets to liver surgery in the 1980s, but exhibited drawbacks partly related to the excess water supply required and unsuitability for application to microsurgical instruments intended for deep, narrow lesions (endoscopic instrumentation and catheters) due to limitations in miniaturization of the device. To solve these issues, we initiated work on the pulsed micro-liquid jet. The idea of the pulsed micro-liquid jet originated from the observation of tissue damage by shock/bubble interactions during extracorporeal shock wave lithotripsy and evolved into experimental application for recanalization of cerebral embolisms in the 1990s. The original method of generating the liquid jet was based on air bubble formation and microexplosives as the shock wave source, and as such could not be applied clinically. The air bubble was replaced by a holmium:yttrium-aluminum-garnet (Ho:YAG) laser-induced bubble. Finally, the system was simplified and the liquid jet was generated via irradiation from the Ho:YAG laser within a liquid-filled tubular structure. A series of investigations revealed that this pulsed laser-induced liquid jet (LILJ) system has equivalent dissection and blood vessel preservation characteristics, but the amount of liquid usage has been reduced to less than 2 μ l per shot and can easily be incorporated into microsurgical, endoscopic, and catheter devices. As a first step in human clinical studies, we have applied the LILJ system for the treatment of skull base tumors through the transsphenoidal approach in 9 patients (7 pituitary adenomas and 2 chordomas), supratentorial glioma (all high grade glioma) in 8 patients, including one with

Perspective on Lithotripsy Adverse Effects

NASA Astrophysics Data System (ADS)

Knoll, Thomas; Wendt-Nordahl, Gunnar

2008-09-01

Shock wave lithotripsy (SWL) is an effective and without any doubt the least invasive procedure to treat upper urinary tract calculi. Acute complications are rarely reported and do not require specific treatment in most cases. However, one should be aware that energy levels sufficient for stone breakage are capable of damaging tissue as well, and significant hematoma—not only in the kidney but as well in surrounding organs—has been observed. Furthermore, only little is known about the long-term effects of SWL. Some authors have reported an increased incidence of hypertension and possibly also diabetes mellitus. Such chronic diseases—if indeed related to prior SWL—may be a late result of acute SWL-related trauma but the discussion on the underlying pathogenesis is controversial. Many factors have to be considered, such as the natural history of recurrent stone formers, technical principles of SWL, and differences in treatment protocols. Promising studies are currently underway to optimize stone breakage while limiting potential collateral damage. With this progress, SWL remains a safe treatment option for most urinary calculi.

Endoscopic therapy of neoplasia related to Barrett's esophagus and endoscopic palliation of esophageal cancer.

PubMed

Vignesh, Shivakumar; Hoffe, Sarah E; Meredith, Kenneth L; Shridhar, Ravi; Almhanna, Khaldoun; Gupta, Akshay K

2013-04-01

Barrett's esophagus (BE) is the most important identifiable risk factor for the progression to esophageal adenocarcinoma. This article reviews the current endoscopic therapies for BE with high-grade dysplasia and intramucosal cancer and briefly discusses the endoscopic palliation of advanced esophageal cancer. The diagnosis of low-grade or high-grade dysplasia (HGD) is based on several cytologic criteria that suggest neoplastic transformation of the columnar epithelium. HGD and carcinoma in situ are regarded as equivalent. The presence of dysplasia, particularly HGD, is also a risk factor for synchronous and metachronous adenocarcinoma. Dysplasia is a marker of adenocarcinoma and also has been shown to be the preinvasive lesion. Esophagectomy has been the conventional treatment for T1 esophageal cancer and, although debated, is an appropriate option in some patients with HGD due to the presence of occult cancer in over one-third of patients. Endoscopic ablative modalities (eg, photodynamic therapy and cryoablation) and endoscopic resection techniques (eg, endoscopic mucosal resection) have demonstrated promising results. The significant morbidity and mortality of esophagectomy makes endoscopic treatment an attractive potential option.

Evaluation of the learning curve for thulium laser enucleation of the prostate with the aid of a simulator tool but without tutoring: comparison of two surgeons with different levels of endoscopic experience.

PubMed

Saredi, Giovanni; Pirola, Giacomo Maria; Pacchetti, Andrea; Lovisolo, Jon Alexander; Borroni, Giacomo; Sembenini, Federico; Marconi, Alberto Mario

2015-06-09

The aim of this study was to determine the learning curve for thulium laser enucleation of the prostate (ThuLEP) for two surgeons with different levels of urological endoscopic experience. From June 2012 to August 2013, ThuLEP was performed on 100 patients in our institution. We present the results of a prospective evaluation during which we analyzed data related to the learning curves for two surgeons of different levels of experience. The prostatic adenoma volumes ranged from 30 to 130 mL (average 61.2 mL). Surgeons A and B performed 48 and 52 operations, respectively. Six months after surgery, all patients were evaluated with the International Prostate Symptom Score questionnaire, uroflowmetry, and prostate-specific antigen test. Introduced in 2010, ThuLEP consists of blunt enucleation of the prostatic apex and lobes using the sheath of the resectoscope. This maneuver allows clearer visualization of the enucleation plane and precise identification of the prostatic capsule. These conditions permit total resection of the prostatic adenoma and coagulation of small penetrating vessels, thereby reducing the laser emission time. Most of the complications in this series were encountered during morcellation, which in some cases was performed under poor vision because of venous bleeding due to surgical perforation of the capsule during enucleation. Based on this analysis, we concluded that it is feasible for laser-naive urologists with endoscopic experience to learn to perform ThuLEP without tutoring. Those statements still require further validation in larger multicentric study cohort by several surgeon. The main novelty during the learning process was the use of a simulator that faithfully reproduced all of the surgical steps in prostates of various shapes and volumes.

Endoscope-Assisted Transoral Fixation of Mandibular Condyle Fractures: Submandibular Versus Transoral Endoscopic Approach.

PubMed

Hwang, Na-Hyun; Lee, Yoon-Hwan; You, Hi-Jin; Yoon, Eul-Sik; Kim, Deok-Woo

2016-07-01

In recent years, endoscope-assisted transoral approach for condylar fracture treatment has attracted much attention. However, the surgical approach is technically challenging: the procedure requires specialized instruments and the surgeons experience a steep learning curve. During the transoral endoscopic (TE) approach several instruments are positioned through a narrow oral incision making endoscope maneuvering very difficult. For this reason, the authors changed the entry port of the endoscope from transoral to submandibular area through a small stab incision. The aim of this study is to assess the advantage of using the submandibular endoscopic intraoral approach (SEI).The SEI approach requires intraoral incision for fracture reduction and fixation, and 4 mm size submandibular stab incision for endoscope and traction wires. Fifteen patients with condyle neck and subcondyle fractures were operated under the submandibular approach and 15 patients with the same diagnosis were operated under the standard TE approach.The SEI approach allowed clear visualization of the posterior margin of the ramus and condyle, and the visual axis was parallel to the condyle ramus unit. The TE approach clearly shows the anterior margin of the condyle and the sigmoid notch. The surgical time of the SEI group was 128 minutes and the TE group was 120 minutes (P >0.05). All patients in the TE endoscope group were fixated with the trocar system, but only 2 lower neck fracture patients in the SEI group required a trocar. The other 13 subcondyle fractures were fixated with an angulated screw driver (P <0.05). There were no differences in complication and surgical outcomes.The submandibular endoscopic approach has an advantage of having more space with good visualization, and facilitated the use of an angulated screw driver.

Classification of atrophic mucosal patterns on Blue LASER Imaging for endoscopic diagnosis of Helicobacter pylori-related gastritis: A retrospective, observational study.

PubMed

Nishikawa, Yoshiyuki; Ikeda, Yoshio; Murakami, Hidehiro; Hori, Shin-Ichiro; Hino, Kaori; Sasaki, Chise; Nishikawa, Megumi

2018-01-01

Atrophic gastritis can be classified according to characteristic mucosal patterns observed by Blue LASER Imaging (BLI) in a medium-range to distant view. To facilitate the endoscopic diagnosis of Helicobacter pylori (HP)-related gastritis, we investigated whether atrophic mucosal patterns correlated with HP infection based on the image interpretations of three endoscopists blinded to clinical features. This study included 441 patients diagnosed as having atrophic gastritis by upper gastrointestinal endoscopy at Nishikawa Gastrointestinal Clinic between April 1, 2015 and March 31, 2016. The presence/absence of HP infection was not taken into consideration. Endoscopy was performed using a Fujifilm EG-L580NW scope. Atrophic mucosal patterns observed by BLI were classified into Spotty, Cracked and Mottled. Image interpretation results were that 89, 122 and 228 patients had the Spotty, Cracked and Mottled patterns, respectively, and 2 patients an undetermined pattern. Further analyses were performed on 439 patients, excluding the 2 with undetermined patterns. The numbers of patients testing negative/positive for HP infection in the Spotty, Cracked and Mottled pattern groups were 12/77, 105/17, and 138/90, respectively. The specificity, positive predictive value and positive likelihood ratio for endoscopic diagnosis with positive HP infection based on the Spotty pattern were 95.3%, 86.5% and 8.9, respectively. In all patients with the Spotty pattern before HP eradication, the Cracked pattern was observed on subsequent post-eradication endoscopy. The Spotty pattern may represent the presence of HP infection, the Cracked pattern, a post-inflammatory change as seen after HP eradication, and the Mottled pattern, intestinal metaplasia.

Transvaginal endoscopic partial gastrectomy in porcine models: the role of an extra endoscope for gastric control.

PubMed

Nakajima, Kiyokazu; Takahashi, Tsuyoshi; Souma, Yoshihito; Shinzaki, Shinichiro; Yamada, Takuya; Yoshio, Toshiyuki; Nishida, Toshirou

2008-12-01

Transvaginal natural orifice translumenal endoscopic surgery (NOTES) gastrectomy is technically challenging, because wide perigastric dissection under appropriate tissue triangulation is unfeasible with current endoscopic instruments alone. The aim of this study was to investigate the feasibility of transvaginal NOTES gastrectomy with the use of an extra endoscope as a retracting device of the stomach. This acute in vivo feasibility study was performed under the approval of the Institutional Animal Care and Use Committee (IACUC). Four female 40-kg pigs received general anesthesia and underwent transvaginal endoscopic partial gastrectomy. Under laparoscopic guidance, the uterus was fixed anteriorly and transvaginal access was established in a standard fashion. The perigastric ligaments were dissected with needle knife/insulation-tipped electrosurgical knife (IT) via transvaginally placed double-channel endoscope. This step was assisted with the second, CO(2)-insufflating endoscope advanced in the stomach (i.e., so-called endoscopic gastric control). A linear stapling device with a flexible shaft was then passed transvaginally, and the anterior gastric wall was partially resected. The specimen was isolated and retrieved through the vagina. Concluding endoscopy was carried out to confirm the absence of mucosal damage due to endoscopic gastric control. This was further confirmed at necropsy immediately after sacrifice. All animals underwent successful transvaginal NOTES gastrectomy. Endoscopic gastric control greatly facilitated perigastric dissection by providing appropriate tissue countertraction on the ligaments. Use of transabdominal (laparoscopic) graspers was thus minimized. There were no intraoperative complications directly related to use of the primary (transvaginal) endoscope or the additional (gastric) endoscope. Distention of downstream bowel after gastric insufflation was minimal with CO(2). No major injuries were noted on gastric mucosa at postmortem

Building an endoscopic ear surgery program.

PubMed

Golub, Justin S

2016-10-01

This article discusses background, operative details, and outcomes of endoscopic ear surgery. This information will be helpful for those establishing a new program. Endoscopic ear surgery is growing in popularity. The ideal benefit is in totally transcanal access that would otherwise require a larger incision. The endoscope carries a number of advantages over the microscope, as well as some disadvantages. Several key maneuvers can minimize disadvantages. There is a paucity of studies directly comparing outcomes between endoscopic and microscopic approaches for the same procedure. The endoscope is gaining acceptance as a tool for treating otologic diseases. For interested surgeons, this article can help bridge the transition from microscopic to totally transcanal endoscopic ear surgery for appropriate disease.

Correlation between endoscopic forceps biopsies and endoscopic mucosal resection with endoscopic ultrasound in patients with Barrett's esophagus with high-grade dysplasia and early cancer.

PubMed

Thota, Prashanthi N; Sada, Alaa; Sanaka, Madhusudhan R; Jang, Sunguk; Lopez, Rocio; Goldblum, John R; Liu, Xiuli; Dumot, John A; Vargo, John; Zuccarro, Gregory

2017-03-01

Patients with Barrett's esophagus (BE) and high-grade dysplasia (HGD) or intramucosal cancer (IMC) on endoscopic forceps biopsies are referred to endoscopic therapy even though forceps biopsies do not reflect the disease extent accurately. Endoscopic mucosal resection (EMR) and endoscopic ultrasound (EUS) are frequently used for staging prior to endoscopic therapy. Our aims were to evaluate: (1) if endoscopic forceps biopsies correlated with EMR histology in these patients; (2) the utility of EUS compared to EMR; and (3) if accuracy of EUS varied based on grade of differentiation of tumor. This is a retrospective review of patients referred to endoscopic therapy of BE with HGD or early esophageal adenocarcinoma (EAC) who underwent EMR from 2006 to 2011. Age, race, sex, length of Barrett's segment, hiatal hernia size, number of endoscopies and biopsy results and EUS findings were abstracted. A total of 151 patients underwent EMR. In 50 % (75/151) of patients, EMR histology was consistent with endoscopic forceps biopsy findings. EMR resulted in change in diagnosis with upstaging in 21 % (32/151) and downstaging in 29 % (44/151). In patients with HGD on EMR, EUS staging was T0 in 74.1 % (23/31) but upstaged in 25.8 % (8/31). In patients with IMC on EMR, EUS findings were T1a in 23.6 % (9/38), upstaged in 18.4 % (7/38) and downstaged in 57.8 % (22/38). EUS accurately identified EMR histology in all submucosal cancers. Grade of differentiation was reported in 24 cancers on EMR histology. There was no correlation between grade and EUS staging. EUS is of limited utility in accurate staging of BE patients with HGD or early EAC. Endoscopic forceps biopsy correlated with EMR findings in only 50 % of patients. Irrespective of the endoscopic forceps biopsy results, all BE patients with visible lesions should be referred to EMR.

Accuracy of endoscopic intraoperative assessment of urologic stone size.

PubMed

Patel, Nishant; Chew, Ben; Knudsen, Bodo; Lipkin, Michael; Wenzler, David; Sur, Roger L

2014-05-01

Endoscopic treatment of renal calculi relies on surgeon assessment of residual stone fragment size for either basket removal or for the passage of fragments postoperatively. We therefore sought to determine the accuracy of endoscopic assessment of renal calculi size. Between January and May 2013, five board-certified endourologists participated in an ex vivo artificial endoscopic simulation. A total of 10 stones (pebbles) were measured (mm) by nonparticipating urologist (N.D.P.) with electronic calibers and placed into separate labeled opaque test tubes to prevent visualization of the stones through the side of the tube. Endourologists were blinded to the actual size of the stones. A flexible digital ureteroscope with a 200-μm core sized laser fiber in the working channel as a size reference was placed through the ureteroscope into the test tube to estimate the stone size (mm). Accuracy was determined by obtaining the correlation coefficient (r) and constructing an Altman-Bland plot. Endourologists tended to overestimate actual stone size by a margin of 0.05 mm. The Pearson correlation coefficient was r=0.924, with a p-value<0.01. The estimation of small stones (<4 mm) had a greater accuracy than large stones (≥4 mm), r=0.911 vs r=0.666. Altman-bland plot analysis suggests that surgeons are able to accurately estimate stone size within a range of -1.8 to +1.9 mm. This ex vivo simulation study demonstrates that endoscopic assessment is reliable when assessing stone size. On average, there was a slight tendency to overestimate stone size by 0.05 mm. Most endourologists could visually estimate stone size within 2 mm of the actual size. These findings could be generalized to state that endourologists are accurately able to intraoperatively assess residual stone fragment size to guide decision making.

Modeling elastic wave propagation in kidney stones with application to shock wave lithotripsy.

PubMed

Cleveland, Robin O; Sapozhnikov, Oleg A

2005-10-01

A time-domain finite-difference solution to the equations of linear elasticity was used to model the propagation of lithotripsy waves in kidney stones. The model was used to determine the loading on the stone (principal stresses and strains and maximum shear stresses and strains) due to the impact of lithotripsy shock waves. The simulations show that the peak loading induced in kidney stones is generated by constructive interference from shear waves launched from the outer edge of the stone with other waves in the stone. Notably the shear wave induced loads were significantly larger than the loads generated by the classic Hopkinson or spall effect. For simulations where the diameter of the focal spot of the lithotripter was smaller than that of the stone the loading decreased by more than 50%. The constructive interference was also sensitive to shock rise time and it was found that the peak tensile stress reduced by 30% as rise time increased from 25 to 150 ns. These results demonstrate that shear waves likely play a critical role in stone comminution and that lithotripters with large focal widths and short rise times should be effective at generating high stresses inside kidney stones.

Design and characterization of an optimized simultaneous color and near-infrared fluorescence rigid endoscopic imaging system

NASA Astrophysics Data System (ADS)

Venugopal, Vivek; Park, Minho; Ashitate, Yoshitomo; Neacsu, Florin; Kettenring, Frank; Frangioni, John V.; Gangadharan, Sidhu P.; Gioux, Sylvain

2013-12-01

We report the design, characterization, and validation of an optimized simultaneous color and near-infrared (NIR) fluorescence rigid endoscopic imaging system for minimally invasive surgery. This system is optimized for illumination and collection of NIR wavelengths allowing the simultaneous acquisition of both color and NIR fluorescence at frame rates higher than 6.8 fps with high sensitivity. The system employs a custom 10-mm diameter rigid endoscope optimized for NIR transmission. A dual-channel light source compatible with the constraints of an endoscope was built and includes a plasma source for white light illumination and NIR laser diodes for fluorescence excitation. A prism-based 2-CCD camera was customized for simultaneous color and NIR detection with a highly efficient filtration scheme for fluorescence imaging of both 700- and 800-nm emission dyes. The performance characterization studies indicate that the endoscope can efficiently detect fluorescence signal from both indocyanine green and methylene blue in dimethyl sulfoxide at the concentrations of 100 to 185 nM depending on the background optical properties. Finally, we performed the validation of this imaging system in vivo during a minimally invasive procedure for thoracic sentinel lymph node mapping in a porcine model.

Pre-emptive tramadol could reduce pain after ureteroscopic lithotripsy.

PubMed

Mimić, Ana; Denčić, Nataša; Jovičić, Jelena; Mirković, Jelena; Durutović, Otaš; Milenković-Petronić, Dragica; Lađević, Nebojša

2014-09-01

Optimal analgesia in ambulatory urology patients still remains a challenge. The aim of this study was to examine if the pre-emptive use of intravenous tramadol can reduce pain after ureteroscopic lithotripsy in patients diagnosed with unilateral ureteral stones. This prospective pilot cohort study included 74 patients diagnosed with unilateral ureteral stones who underwent ureteroscopic lithotripsy under general anesthesia in the Urology Clinic at the Clinical Center of Serbia from March to June 2012. All patients were randomly allocated to two groups: one group (38 patients) received intravenous infusion of tramadol 100 mg in 500 mL 0.9%NaCl one hour before the procedure, while the other group (36 patients) received 500 mL 0.9%NaCl at the same time. Visual analogue scale (VAS) scores were recorded once prior to surgery and two times after the surgery (1 h and 6 h, respectively). The patients were prescribed additional postoperative analgesia (diclofenac 75 mg i.m.) when required. Pre-emptive effects of tramadol were assessed measuring pain scores, VAS1 and VAS2, intraoperative fentanyl consumption, and postoperative analgesic requirement. The average VAS1 score in the tramadol group was significantly lower than that in the non-tramadol group. The difference in average VAS2 score values between the two groups was not statistically significant; however, there were more patients who experienced severe pain in the non-tramadol group (p<0.01). The number of patients that required postoperative analgesia was not statistically different between the groups. Pre-emptive tramadol did reduce early postoperative pain. The patients who received pre-emptive tramadol were less likely to experience severe post-operative pain.

Sterilization of endoscopic instruments.

PubMed

Sabnis, Ravindra B; Bhattu, Amit; Vijaykumar, Mohankumar

2014-03-01

Sterilization of endoscopic instruments is an important but often ignored topic. The purpose of this article is to review the current literature on the sterilization of endoscopic instruments and elaborate on the appropriate sterilization practices. Autoclaving is an economic and excellent method of sterilizing the instruments that are not heat sensitive. Heat sensitive instruments may get damaged with hot sterilization methods. Several new endoscopic instruments such as flexible ureteroscopes, chip on tip endoscopes, are added in urologists armamentarium. Many of these instruments are heat sensitive and hence alternative efficacious methods of sterilization are necessary. Although ethylene oxide and hydrogen peroxide are excellent methods of sterilization, they have some drawbacks. Gamma irradiation is mainly for disposable items. Various chemical agents are widely used even though they achieve high-level disinfection rather than sterilization. This article reviews various methods of endoscopic instrument sterilization with their advantages and drawbacks. If appropriate sterilization methods are adopted, then it not only will protect patients from procedure-related infections but prevent hypersensitive allergic reactions. It will also protect instruments from damage and increase its longevity.

[The development of endoscope workstation].

PubMed

Qi, L; Qi, L; Qiou, Q J; Yu, Q L

2001-01-01

This paper introduces an endoscope workstation, which solved the weak points of multimedia endoscope database used by most hospitals. The endoscope workstation was built on pedal-switch and NTFS file system. This paper also Introduces how to make program optimal and quick inputting. The workstation has promoted the efficiency of the doctor's operation.

Diagnostic and therapeutic direct peroral cholangioscopy using an intraductal anchoring balloon

PubMed Central

Parsi, Mansour A; Stevens, Tyler; Vargo, John J

2012-01-01

AIM: To report our experience using a recently introduced anchoring balloon for diagnostic and therapeutic direct peroral cholangioscopy (DPOC). METHODS: Consecutive patients referred for diagnostic or therapeutic peroral cholangioscopy were evaluated in a prospective cohort study. The patients underwent DPOC using an intraductal anchoring balloon, which was recently introduced to allow consistent access to the biliary tree with an ultraslim upper endoscope. The device was later voluntarily withdrawn from the market by the manufacturer. RESULTS: Fourteen patients underwent DPOC using the anchoring balloon. Biliary access with an ultraslim upper endoscope was accomplished in all 14 patients. In 12 (86%) patients, ductal access required sphincteroplasty with a 10-mm dilating balloon. Intraductal placement of the ultraslim upper endoscope allowed satisfactory visualization of the biliary mucosa to the level of the confluence of the right and left hepatic ducts in 13 of 14 patients (93%). Therapeutic interventions by DPOC were successfully completed in all five attempted cases (intraductal biopsy in one and DPOC guided laser lithotripsy in four). Adverse events occurred in a patient on immunosuppressive therapy who developed an intrahepatic biloma at the site of the anchoring balloon. This required hospitalization and antibiotics. Repeat endoscopic retrograde cholangiopancreatography 8 wk after the index procedure showed resolution of the biloma. CONCLUSION: Use of this anchoring balloon allowed consistent access to the biliary tree for performance of diagnostic and therapeutic DPOC distal to the biliary bifurcation. PMID:22912549

Endoscopic resection of subepithelial tumors

PubMed Central

Schmidt, Arthur; Bauder, Markus; Riecken, Bettina; Caca, Karel

2014-01-01

Management of subepithelial tumors (SETs) remains challenging. Endoscopic ultrasound (EUS) has improved differential diagnosis of these tumors but a definitive diagnosis on EUS findings alone can be achieved in the minority of cases. Complete endoscopic resection may provide a reasonable approach for tissue acquisition and may also be therapeutic in case of malignant lesions. Small SET restricted to the submucosa can be removed with established basic resection techniques. However, resection of SET arising from deeper layers of the gastrointestinal wall requires advanced endoscopic methods and harbours the risk of perforation. Innovative techniques such as submucosal tunneling and full thickness resection have expanded the frontiers of endoscopic therapy in the past years. This review will give an overview about endoscopic resection techniques of SET with a focus on novel methods. PMID:25512768

Endoscopic resection of subepithelial tumors.

PubMed

Schmidt, Arthur; Bauder, Markus; Riecken, Bettina; Caca, Karel

2014-12-16

Management of subepithelial tumors (SETs) remains challenging. Endoscopic ultrasound (EUS) has improved differential diagnosis of these tumors but a definitive diagnosis on EUS findings alone can be achieved in the minority of cases. Complete endoscopic resection may provide a reasonable approach for tissue acquisition and may also be therapeutic in case of malignant lesions. Small SET restricted to the submucosa can be removed with established basic resection techniques. However, resection of SET arising from deeper layers of the gastrointestinal wall requires advanced endoscopic methods and harbours the risk of perforation. Innovative techniques such as submucosal tunneling and full thickness resection have expanded the frontiers of endoscopic therapy in the past years. This review will give an overview about endoscopic resection techniques of SET with a focus on novel methods.

Laser probes for noninvasive coagulation of subsurface tissues

NASA Astrophysics Data System (ADS)

Chung, Chia-Chun; Permpongkosol, Sompol; Varkarakis, Ioannis M.; Lima, Guilherme; Franco, Nicholas; Hayman, Michael H.; Nicol, Theresa; Fried, Nathaniel M.

2006-02-01

Previous ex vivo tissue studies utilizing deep laser heating combined with contact cooling of the tissue surface produced noninvasive thermal destruction of subsurface tissue structures in skin and liver samples. This study describes the design and preliminary in vivo testing of two integrated laser/cooling probes for simultaneous Nd:YAG laser irradiation and sapphire contact cooling of liver and skin tissues in an in vivo, acute porcine model for potential use in laparoscopic and endoscopic surgery. Nd:YAG laser radiation with a wavelength of 1.06 μm, power of 20 W, 7.5-mm-diameter spot, 500-ms pulse length, and repetition rate of 0.625 Hz, was delivered to the tissue with a total irradiation time of 16 s. The tissue surface was continuously cooled with a sapphire plate maintained at -5 °C, and with pre- and post-ablation cooling times measuring 120 s and 30 s, resulting in a total operation time of 166 s per a lesion. Thermal lesions were created in liver and skin at a 1-mm depth below the tissue surface and with a 3-4 mm diameter. The laser parameters and lesion dimensions were comparable to previous ex vivo tissue studies. Preliminary in vivo animal studies demonstrate noninvasive creation of subsurface thermal lesions in tissue using Nd:YAG laser irradiation in conjunction with sapphire contact cooling. Chronic wound healing studies will be necessary to optimize the laser and cooling parameters. Potential clinical applications include endoscopic laser treatment of female stress urinary incontinence and thermal coagulation of early stage bladder tumors.

Quantification of holmium:YAG optical tip degradation

NASA Astrophysics Data System (ADS)

Mues, Adam C.; Teichman, Joel M. H.; Knudsen, Bodo E.

2009-02-01

The holmium:yttrium aluminum garnet (YAG) laser is the gold standard laser for intracorporeal lithotripsy. Optical fibers are utilized to transmit laser energy to the surface of a stone for fragmentation. During lithotripsy, fiber tip degradation (burn back) can occur. The exact mechanism for tip degradation and related factors are not completely understood, and have not been investigated. This characteristic is important because fiber burn back may affect diminish fragmentation efficiency, increase operative time, and increase cost due to the need for fiber replacement. We hypothesize that fiber tip degradation (burn back) varies amongst different commercially available holmium:YAG laser fibers.

Agents for gallstone dissolution.

PubMed

Pitt, H A; McFadden, D W; Gadacz, T R

1987-02-01

Numerous methods are presently available for gallstone dissolution, including oral bile salts; cholesterol solvents such as mono-octanoin and methyl tert-butyl ether; calcium or pigment solvents such as EDTA and polysorbate; mechanical extraction techniques through a T-tube tract or after endoscopic sphincterotomy; or fragmentation methods such as ultrasonography or electrohydraulic lithotripsy, lasers, and extracorporeal shock waves. Which, if any, of these methods will be appropriate for an individual patient depends on the type of stones, whether they are in the gallbladder or bile ducts, whether access to the biliary tree is available, the patient's age and general medical condition, and the availability of expert radiologists, endoscopists, and newer equipment. In the United States, the only available oral bile salt for cholesterol gallstone dissolution is chenodeoxycholate. Ursodeoxycholate, which is more rapid and less toxic, has not been approved by the Federal Drug Administration. These agents are most effective in thin women with small, floating, radiolucent cholesterol gallstones in a functioning gallbladder. Only about half of this small subset of patients, however, will experience partial or complete dissolution of stones in 6 to 12 months. Moreover, recurrence is very likely, and the potential toxicity of long-term therapy is unknown. Thus, for most patients, cholecystectomy remains the most cost-effective and, perhaps, safest option. Intragallbladder instillation of methyl tert-butyl ether and extracorporeal shock wave therapy are also likely to be applicable to only small subsets of patients and to be associated with high recurrence rates. In patients with retained ductal cholesterol stones and access to the biliary tree, mono-octanoin therapy is advantageous in that it can be begun as soon as cholangiography demonstrates no extravasation. In properly selected patients, a 90 percent success rate with mono-octanoin infusion can be expected within a

Submucosal tunnel endoscopy: Peroral endoscopic myotomy and peroral endoscopic tumor resection

PubMed Central

Eleftheriadis, Nikolas; Inoue, Haruhiro; Ikeda, Haruo; Onimaru, Manabu; Maselli, Roberta; Santi, Grace

2016-01-01

Peroral endoscopic myotomy (POEM) is an innovative, minimally invasive, endoscopic treatment for esophageal achalasia and other esophageal motility disorders, emerged from the natural orifice transluminal endoscopic surgery procedures, and since the first human case performed by Inoue in 2008, showed exciting results in international level, with more than 4000 cases globally up to now. POEM showed superior characteristics than the standard 100-year-old surgical or laparoscopic Heller myotomy (LHM), not only for all types of esophageal achalasia [classical (I), vigorous (II), spastic (III), Chicago Classification], but also for advanced sigmoid type achalasia (S1 and S2), failed LHM, or other esophageal motility disorders (diffuse esophageal spasm, nutcracker esophagus or Jackhammer esophagus). POEM starts with a mucosal incision, followed by submucosal tunnel creation crossing the esophagogastric junction (EGJ) and myotomy. Finally the mucosal entry is closed with endoscopic clip placement. POEM permitted relatively free choice of myotomy length and localization. Although it is technically demanding procedure, POEM can be performed safely and achieves very good control of dysphagia and chest pain. Gastroesophageal reflux is the most common troublesome side effect, and is well controllable with proton pump inhibitors. Furthermore, POEM opened the era of submucosal tunnel endoscopy, with many other applications. Based on the same principles with POEM, in combination with new technological developments, such as endoscopic suturing, peroral endoscopic tumor resection (POET), is safely and effectively applied for challenging submucosal esophageal, EGJ and gastric cardia tumors (submucosal tumors), emerged from muscularis propria. POET showed up to know promising results, however, it is restricted to specialized centers. The present article reviews the recent data of POEM and POET and discussed controversial issues that need further study and future perspectives. PMID

Development of optical laser balloon and drainage from radiation vulcanized natural rubber latex

NASA Astrophysics Data System (ADS)

Shimamura, Yoshiyuki

Rubber film made of radiation vulcanized natural rubber latex (RVNRL) has better transparency and lower toxicity compared with sulfur-vulcanized latex film. Optical laser balloon (optical endoscopical balloon) and drainage were developed by using RVNRL. An endoscope was equipped with a saline-filled latex rubber balloon at its tip to displace contaminating blood, bile, or gastric contents during operative portoscopy, biliary endoscopy, or upper gastrointestinal endoscopy. The transmission of Nd-Yag laser through the balloon is 98%, higher than the sulfur-vulcanized latex rubber (75%). High transparency of the drainage bag facilitated easy observation of discharged fluids without detaching the bag from the tube.

Endoscopic techniques in aesthetic plastic surgery.

PubMed

McCain, L A; Jones, G

1995-01-01

There has been an explosive interest in endoscopic techniques by plastic surgeons over the past two years. Procedures such as facial rejuvenation, breast augmentation and abdominoplasty are being performed with endoscopic assistance. Endoscopic operations require a complex setup with components such as video camera, light sources, cables and hard instruments. The Hopkins Rod Lens system consists of optical fibers for illumination, an objective lens, an image retrieval system, a series of rods and lenses, and an eyepiece for image collection. Good illumination of the body cavity is essential for endoscopic procedures. Placement of the video camera on the eyepiece of the endoscope gives a clear, brightly illuminated large image on the monitor. The video monitor provides the surgical team with the endoscopic image. It is important to become familiar with the equipment before actually doing cases. Several options exist for staff education. In the operating room the endoscopic cart needs to be positioned to allow a clear unrestricted view of the video monitor by the surgeon and the operating team. Fogging of the endoscope may be prevented during induction by using FREDD (a fog reduction/elimination device) or a warm bath. The camera needs to be white balanced. During the procedure, the nurse monitors the level of dissection and assesses for clogging of the suction.

Endoscopic approaches to treatment of achalasia

PubMed Central

Friedel, David; Modayil, Rani; Iqbal, Shahzad; Grendell, James H.

2013-01-01

Endoscopic therapy for achalasia is directed at disrupting or weakening the lower esophageal sphincter (LES). The two most commonly utilized endoscopic interventions are large balloon pneumatic dilation (PD) and botulinum toxin injection (BTI). These interventions have been extensively scrutinized and compared with each other as well as with surgical disruption (myotomy) of the LES. PD is generally more effective in improving dysphagia in achalasia than BTI, with the latter reserved for infirm older people, and PD may approach treatment results attained with myotomy. However, PD may need to be repeated. Small balloon dilation and endoscopic stent placement for achalasia have only been used in select centers. Per oral endoscopic myotomy is a newer endoscopic modality that will likely change the treatment paradigm for achalasia. It arose from the field of natural orifice transluminal endoscopic surgery and represents a scarless endoscopic approach to Heller myotomy. This is a technique that requires extensive training and preparation and thus there should be rigorous accreditation and monitoring of outcomes to ensure safety and efficacy. PMID:23503707

Comparison of Complications Rates in Endoscopic Surgery Performed by a Clinical Assistant vs. An Experienced Endoscopic Surgeon

PubMed Central

Singhi, Aditi

2009-01-01

Study Objectives: (a) To find out the actual incidence of complications during endoscopic surgeries. (b) Comparison of complication rate between an experienced laparoscopic surgeon (> 10 years of experience in endoscopic surgery) and a clinical assistant (> 3 years of experience in endoscopic surgery). (c) How to manage complications in endoscopic surgery. (d) Concrete suggestions to reduce the complication rate. Design: Retrospective study (Canadian Task Force classification ii-2). Setting: Tertiary gynecologic endoscopic unit. Patients: A total of 3204 cases of gynecologic endoscopic surgery out of which 2001 were laparoscopic and 1203 were hysteroscopic surgeries. Interventions: Laparoscopic and hysteroscopic gynecologic surgeries in indicated cases. Measurements and Main Results: The study was carried out between April 2003 and October 2007 at a referral center for endoscopic surgery. A total of 3204 cases of gynecologic endoscopic surgery were studied. There were five significant complications in laparoscopic surgeries and four significant complications in hysteroscopic surgeries seen in four years and six months. All the complications could be managed with no mortality. Conversion to laparotomy was needed in eight cases of laparoscopic surgeries and none in hysteroscopic surgeries. Conclusion: The risk of complication reduces with the experience in endoscopic surgery. However, the proper grooming of a novice in experienced hands, for a sufficient period of time, can minimize the complication rate in the initial learning phase. The complication may be utilized as a stepping-stone to overcome any given situation without panic, but with adequate safety. PMID:22442510

A low or high BMI is a risk factor for renal hematoma after extracorporeal shock wave lithotripsy for kidney stones.

PubMed

Nussberger, Fabio; Roth, Beat; Metzger, Tobias; Kiss, Bernhard; Thalmann, George N; Seiler, Roland

2017-06-01

The purpose of this study was to evaluate risk factors for renal hematoma after extracorporeal shock wave lithotripsy (SWL) for kidney stones in a matched case-control analysis of a subgroup of patients recruited from a prospective randomized cohort. Between 06/2010 and 03/2013, 418 patients underwent SWL with the MODULITH ® -SLX-F2-lithotripter for kidney stones. In 39/418 patients (9 %), ultrasound at post-treatment day 1 revealed renal hematomas. For 37 of these patients, a matched group without hematoma could be selected according to the following matching criteria: age, gender, number and energy of shock waves, stone burden and localization. Risk factors for renal hematoma after SWL were compared between the two groups. The rates of diabetes, stopped anticoagulant/antiplatelet medications and arterial hypertension were not different between the two groups (p > 0.2). The skin-kidney distance was virtually the same in both groups (p = 0.5). In the hematoma group, significantly more patients had a high (>30: n = 16) as well as a low (<21.5: n = 4) BMI when compared to the control group (n = 4; n = 0; p < 0.001). Importantly, all patients with BMI <21.5 developed renal hematomas after SWL. Patients with a high (>30) or low (<21.5) BMI had a higher risk for renal damage after SWL. Therefore, alternative endoscopic treatment options should be considered in these patients.

Pre-Emptive Tramadol Could Reduce Pain after Ureteroscopic Lithotripsy

PubMed Central

Denčić, Nataša; Jovičić, Jelena; Mirković, Jelena; Durutović, Otaš; Milenković-Petronić, Dragica; Lađević, Nebojša

2014-01-01

Purpose Optimal analgesia in ambulatory urology patients still remains a challenge. The aim of this study was to examine if the pre-emptive use of intravenous tramadol can reduce pain after ureteroscopic lithotripsy in patients diagnosed with unilateral ureteral stones. Materials and Methods This prospective pilot cohort study included 74 patients diagnosed with unilateral ureteral stones who underwent ureteroscopic lithotripsy under general anesthesia in the Urology Clinic at the Clinical Center of Serbia from March to June 2012. All patients were randomly allocated to two groups: one group (38 patients) received intravenous infusion of tramadol 100 mg in 500 mL 0.9%NaCl one hour before the procedure, while the other group (36 patients) received 500 mL 0.9%NaCl at the same time. Visual analogue scale (VAS) scores were recorded once prior to surgery and two times after the surgery (1 h and 6 h, respectively). The patients were prescribed additional postoperative analgesia (diclofenac 75 mg i.m.) when required. Pre-emptive effects of tramadol were assessed measuring pain scores, VAS1 and VAS2, intraoperative fentanyl consumption, and postoperative analgesic requirement. Results The average VAS1 score in the tramadol group was significantly lower than that in the non-tramadol group. The difference in average VAS2 score values between the two groups was not statistically significant; however, there were more patients who experienced severe pain in the non-tramadol group (p<0.01). The number of patients that required postoperative analgesia was not statistically different between the groups. Conclusion Pre-emptive tramadol did reduce early postoperative pain. The patients who received pre-emptive tramadol were less likely to experience severe post-operative pain. PMID:25048508

Endoscopic Treatment of Upper Tract Urothelial Carcinoma.

PubMed

Verges, Daniel P; Lallas, Costas D; Hubosky, Scott G; Bagley, Demetrius H

2017-04-01

This study aims to make the reader be aware of recent trends regarding the endoscopic management of upper tract urothelial carcinoma (UTUC) via review of the urologic literature over the past 5 years. Given the rare incidence of this disease, and the lack of level 1 evidence, systematic reviews and meta-analyses were also evaluated. Studies of importance are also considered and outlined in the annotated reference section. The PubMed database was queried using the following medical subject headings (MeSH terms): "carcinoma, transitional cell," "ureter," "ureteral neoplasms," "kidney pelvis," "endoscopy," "laser therapy," "ureteroscopy," "urologic surgical procedures," and "ureteroscopes." MeSH terms were linked together in varying combinations and limited to human studies in English. Given the relatively rare nature of upper tract urothelial carcinoma (UTUC), level 1 evidence regarding the efficacy of endoscopic treatment does not exist, even after 30+ years of experience. Rather, the literature available mostly is in the form of single institutional retrospective series consisting of relatively small numbers of patients with short to intermediate follow-up. Only within the last 3 years have published series with larger numbers of patients and mean follow-up over 5 years been made available. Even with these more robust experiences, comparisons among series are difficult given variable treatment and follow-up approaches. Most endoscopically managed UTUC will locally recur, especially with longer follow-up. Renal preservation rate is high, however, approaching 80% with follow-up well over 3 years. Patients with high-grade disease often fare poorly regardless of treatment modality. As such, endoscopic management for high-grade urothelial carcinoma should only be used in exceptional circumstances (i.e., in those patients medically unfit for NU or those with solitary kidneys wishing to avoid the morbidity of dialysis). No level 1 evidence exists for the routine use

Role of laser photoablative therapy and expandable metal stents in colorectal carcinoma

NASA Astrophysics Data System (ADS)

Chennupati, Raja S.; Trowers, Eugene A.

2000-05-01

Metallic stents are effective in relieving colorectal obstruction in more than 80% of cases. Self expanding metallic stents allow for decompression of the proximal colon and preoperative bowel cleansing. Hence, emergent surgery for large bowel obstruction with its associated high morbidity and mortality might be avoided. Endoscopic laser photoablation and stent placement may successfully palliate inoperable colorectal cancer patients by maintaining luminal patency and avoiding the need for a colostomy. Major complications associated with metallic stents include pressure necrosis, perforation, bleeding and migration. The effectiveness of expandable metallic stents in obstructive colorectal carcinoma is critically reviewed. The authors present a concise review of the effectiveness of endoscopic laser photoablation and expandable metal stent placement.

Endoscopic diode-laser applications in airway surgery

NASA Astrophysics Data System (ADS)

Pankratov, Michail M.; Wang, Zhi; Rebeiz, Elie E.; Perrault, Donald F., Jr.; Shapshay, Stanley M.; Gleich, Lyon L.

1994-09-01

A technique was developed to secure small mucosal grafts onto the airway wound with fibrin/albumin tissue adhesive mixed with ICG dye and irradiated with a 810 nm diode laser. An in vitro study of the tensile strength produced strong mucosal soldering which was adequate to fix grafts in place. In vivo studies showed that wounds with mucosal grafts were completely covered by regenerated squamous cells in 1 week and by ciliated epithelium in 2 weeks. Excellent healing was observed at 6 and 14 days postoperatively and the histology at 28 days found normal epithelium over the vocal cord lesion. This soldering technique is a less traumatic treatment for patients with extensive lesions of the larynx of various origin. Diode laser soldering with ICG-doped fibrin tissue adhesive was evaluated in tracheal anastomosis as a substitute for absorbable sutures. In vitro studies demonstrated strong anastomoses with minimal tissue damage. In vivo animal study showed that these anastomoses had less fibrosis and tissue damage than control animals repaired with sutures only.

The effect of extracorporeal shock wave lithotripsy on the rat spinal cord.

PubMed

Karatas, A; Dosoglu, M; Zeyrek, T; Kayikci, A; Erol, A; Can, B

2008-09-01

Experimental study. To determine the effects of extracorporeal shock wave lithotripsy (ESWL) on the rat spinal cord. Animals were randomly divided into three groups. Groups 1 and 2 consisted of five rats each that underwent ESWL (2000 impulses at 15 kV and 2000 impulses at 18 kV, respectively) and group 3 contained five control rats (no shock wave treatment). ESWL-treated and control rats were compared with regard to light and electron microscopic findings of the adjacent spinal cord. Gross neurological outcomes were normal in all groups. Light microscopic examination of group 1 showed extensive extravasation of red blood cells over all the interstitial spaces. Group 2 also had haemorrhagic areas and an irregular organization of axons in the white matter. Transmission electron microscopic examination of group 1 indicated extravasated red blood cells through the endothelium and swollen axoplasm, degenerated mitochondria, destruction of myelin sheaths and a slight increase in the number of lysosomes. Extravasated red blood cells were also seen in group 2. The axoplasmic mitochondria were enlarged, but no sign of mitochondrial degeneration was observed. Lamellar degeneration of myelin sheaths and abundant lysosomes were more predominant in group 2 than in group 1. Extracorporeal shock wave lithotripsy caused not only haemorrhage but also damage to neuronal structures except the nucleus. Our findings showed that higher-energy ESWL caused more myelin degeneration in the spinal cord.

Complications employing the holmium:YAG laser.

PubMed

Beaghler, M; Poon, M; Ruckle, H; Stewart, S; Weil, D

1998-12-01

We report the operative and early postoperative complications and limitations in 133 patients treated with the holmium laser. Complications included urinary tract infection (N = 3), postoperative bradycardia (1), inverted T-waves (1), intractable flank pain (1), urinary retention (1), inability to access a lower-pole calix with a 365-microm fiber (9), stone migration (5), and termination of procedure because of poor visibility (2). No ureteral perforations or strictures occurred, and no complications were directly attributable to the laser. The holmium laser was capable of fragmenting all urinary calculi in this study. In our initial experience, the holmium laser is safe and effective in the treatment of urinary pathology. Use of laser fibers larger than 200 microm occasionally limits deflection of the endoscope into a lower-pole or dependent calix.

Endoscopic findings following retroperitoneal pancreas transplantation.

PubMed

Pinchuk, Alexey V; Dmitriev, Ilya V; Shmarina, Nonna V; Teterin, Yury S; Balkarov, Aslan G; Storozhev, Roman V; Anisimov, Yuri A; Gasanov, Ali M

2017-07-01

An evaluation of the efficacy of endoscopic methods for the diagnosis and correction of surgical and immunological complications after retroperitoneal pancreas transplantation. From October 2011 to March 2015, 27 patients underwent simultaneous retroperitoneal pancreas-kidney transplantation (SPKT). Diagnostic oesophagogastroduodenoscopy (EGD) with protocol biopsy of the donor and recipient duodenal mucosa and endoscopic retrograde pancreatography (ERP) were performed to detect possible complications. Endoscopic stenting of the main pancreatic duct with plastic stents and three-stage endoscopic hemostasis were conducted to correct the identified complications. Endoscopic methods showed high efficiency in the timely diagnosis and adequate correction of complications after retroperitoneal pancreas transplantation. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Endoscopic submucosal dissection using flexknife.

PubMed

Kodashima, Shinya; Fujishiro, Mitsuhiro; Yahagi, Naohisa; Kakushima, Naomi; Omata, Masao

2006-01-01

Although the standard treatment for early-stage gastrointestinal tumors is still surgical resection, endoscopic resection has been accepted for some of these lesions, especially in Japan. However, the indication was limited until recently to achieve en bloc resection and prevent local recurrence. To overcome the disadvantage of endoscopic resection with conventional endoscopic mucosal resection (EMR), several investigators, including us, have developed a new endoscopic resection technique: endoscopic submucosal dissection (ESD). ESD is a remarkable technique that enables to remove the lesions en bloc regardless of size, shape, coexisting ulcer, and location. Nowadays, several knives are available for ESD, such as the needle knife, insulation-tipped (IT) knife, Hookknife, triangle-tipped (TT) knife, and Flexknife. Each of them has some merits and demerits, and the ways to use the knives are different. We summarize here how to use the Flexknife, which we made ourselves in cooperation with the Olympus Company, and how we use the technique in our hospital.

Image-Guided Biopsy in the Esophagus through Comprehensive Optical Frequency Domain Imaging and Laser Marking: A Study in Living Swine

PubMed Central

Suter, Melissa J.; Jillella, Priyanka A.; Vakoc, Benjamin J.; Halpern, Elkan F.; Mino-Kenudson, Mari; Lauwers, Gregory Y.; Bouma, Brett E.; Nishioka, Norman S.; Tearney, Guillermo J.

2010-01-01

Background Random biopsy esophageal surveillance can be subject to sampling errors, resulting in diagnostic uncertainty. Optical frequency domain imaging (OFDI) is a high-speed, three-dimensional endoscopic microscopy technique. When deployed through a balloon-centering catheter, OFDI can automatically image the entire distal esophagus (6.0 cm length) in approximately 2 minutes. Objective To test a new platform for guided biopsy that allows the operator to select target regions of interest on an OFDI dataset, and then use a laser to mark the esophagus at corresponding locations. The specific goals include determining the optimal laser parameters, testing the accuracy of the laser marking process, evaluating the endoscopic visibility of the laser marks, and assessing the amount of mucosal damage produced by the laser. Design Experimental study conducted in five swine in vivo. Setting Massachusetts General Hospital. Main Outcome Measurements Success rate, including endoscopic visibility of laser marks and accuracy of the laser marking process for selected target sites, and extent of the thermal damage caused by the laser marks. Results All of the laser-induced marks were visible by endoscopy. Target locations were correctly marked with a success rate of 97.07% (95% CI, 89.8%-99.7%). Thermal damage was limited to the superficial layers of the mucosa and was observed to partially heal within 2 days. Limitations An animal study with artificially placed targets to simulate pathology. Conclusions The study demonstrates that laser marking of esophageal sites identified in comprehensive OFDI datasets is feasible and can be performed with sufficient accuracy, precision, and visibility to guide biopsy in vivo. PMID:19879573

Image-guided biopsy in the esophagus through comprehensive optical frequency domain imaging and laser marking: a study in living swine.

PubMed

Suter, Melissa J; Jillella, Priyanka A; Vakoc, Benjamin J; Halpern, Elkan F; Mino-Kenudson, Mari; Lauwers, Gregory Y; Bouma, Brett E; Nishioka, Norman S; Tearney, Guillermo J

2010-02-01

Random biopsy esophageal surveillance can be subject to sampling errors, resulting in diagnostic uncertainty. Optical frequency domain imaging (OFDI) is a high-speed, 3-dimensional endoscopic microscopy technique. When deployed through a balloon-centering catheter, OFDI can automatically image the entire distal esophagus (6.0 cm length) in approximately 2 minutes. To test a new platform for guided biopsy that allows the operator to select target regions of interest on an OFDI dataset, and then use a laser to mark the esophagus at corresponding locations. The specific goals include determining the optimal laser parameters, testing the accuracy of the laser marking process, evaluating the endoscopic visibility of the laser marks, and assessing the amount of mucosal damage produced by the laser. Experimental study conducted in 5 swine in vivo. Massachusetts General Hospital. Success rate, including endoscopic visibility of laser marks and accuracy of the laser marking process for selected target sites, and extent of the thermal damage caused by the laser marks. All of the laser-induced marks were visible by endoscopy. Target locations were correctly marked with a success rate of 97.07% (95% confidence interval, 89.8%-99.7%). Thermal damage was limited to the superficial layers of the mucosa and was observed to partially heal within 2 days. An animal study with artificially placed targets to simulate pathology. The study demonstrates that laser marking of esophageal sites identified in comprehensive OFDI datasets is feasible and can be performed with sufficient accuracy, precision, and visibility to guide biopsy in vivo.

Laser technology and applications in gynaecology.

PubMed

Adelman, M R; Tsai, L J; Tangchitnob, E P; Kahn, B S

2013-04-01

The term 'laser' is an acronym for Light Amplification by Stimulated Emission of Radiation. Lasers are commonly described by the emitted wavelength, which determines the colour of the light, as well as the active lasing medium. Currently, over 40 types of lasers have been developed with a wide range of both industrial and medical uses. Gas and solid-state lasers are frequently used in surgical applications, with CO2 and Ar being the most common examples of gas lasers, and the Nd:YAG and KTP:YAG being the most common examples of solid-state lasers. At present, it appears that the CO2, Nd:YAG, and KTP lasers provide alternative methods for achieving similar results, as opposed to superior results, when compared with traditional endoscopic techniques, such as cold-cutting monopolar and bipolar energy. This review focuses on the physics, tissue interaction, safety and applications of commonly used lasers in gynaecological surgery.

Endoscopic management of pancreatic fluid collections-revisited

PubMed Central

Nabi, Zaheer; Basha, Jahangeer; Reddy, D Nageshwar

2017-01-01

The development of pancreatic fluid collections (PFC) is one of the most common complications of acute severe pancreatitis. Most of the acute pancreatic fluid collections resolve and do not require endoscopic drainage. However, a substantial proportion of acute necrotic collections get walled off and may require drainage. Endoscopic drainage of PFC is now the preferred mode of drainage due to reduced morbidity and mortality as compared to surgical or percutaneous drainage. With the introduction of new metal stents, the efficiency of endoscopic drainage has improved and the task of direct endoscopic necrosectomy has become easier. The requirement of re-intervention is less with new metal stents as compared to plastic stents. However, endoscopic drainage is not free of adverse events. Severe complications including bleeding, perforation, sepsis and embolism have been described with endoscopic approach to PFC. Therefore, the endoscopic management of PFC is a multidisciplinary affair and involves interventional radiologists as well as GI surgeons to deal with unplanned adverse events and failures. In this review we discuss the recent advances and controversies in the endoscopic management of PFC. PMID:28487603

Magnetic anchor guidance for endoscopic submucosal dissection and other endoscopic procedures

PubMed Central

Mortagy, Mohamed; Mehta, Neal; Parsi, Mansour A; Abe, Seiichiro; Stevens, Tyler; Vargo, John J; Saito, Yutaka; Bhatt, Amit

2017-01-01

Endoscopic submucosal dissection (ESD) is a well-established, minimally invasive treatment for superficial neoplasms of the gastrointestinal tract. The universal adoption of ESD has been limited by its slow learning curve, long procedure times, and high risk of complications. One technical challenge is the lack of a second hand that can provide traction, as in conventional surgery. Reliable tissue retraction that exposes the submucosal plane of dissection would allow for safer and more efficient dissection. Magnetic anchor guided endoscopic submucosal dissection (MAG-ESD) has potential benefits compared to other current traction methods. MAG-ESD offers dynamic tissue retraction independent of the endoscope mimicking a surgeon’s “second hand”. Two types of magnets can be used: electromagnets and permanent magnets. In this article we review the MAG-ESD technology, published work and studies of magnets in ESD. We also review the use of magnetic anchor guidance systems in natural orifice transluminal endoscopic surgery and the idea of magnetic non-contact retraction using surface ferromagentization. We discuss the current limitations, the future potential of MAG-ESD and the developments needed for adoption of this technology. PMID:28522906

[Endoscopic full-thickness resection].

PubMed

Meier, B; Schmidt, A; Caca, K

2016-08-01

Conventional endoscopic resection techniques such as endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) are powerful tools for the treatment of gastrointestinal (GI) neoplasms. However, those techniques are limited to the superficial layers of the GI wall (mucosa and submucosa). Lesions without lifting sign (usually arising from deeper layers) or lesions in difficult anatomic positions (appendix, diverticulum) are difficult - if not impossible - to resect using conventional techniques, due to the increased risk of complications. For larger lesions (>2 cm), ESD appears to be superior to the conventional techniques because of the en bloc resection, but the procedure is technically challenging, time consuming, and associated with complications even in experienced hands. Since the development of the over-the-scope clips (OTSC), complications like bleeding or perforation can be endoscopically better managed. In recent years, different endoscopic full-thickness resection techniques came to the focus of interventional endoscopy. Since September 2014, the full-thickness resection device (FTRD) has the CE marking in Europe for full-thickness resection in the lower GI tract. Technically the device is based on the OTSC system and combines OTSC application and snare polypectomy in one step. This study shows all full-thickness resection techniques currently available, but clearly focuses on the experience with the FTRD in the lower GI tract.

Design of wormlike automated robotic endoscope: dynamic interaction between endoscopic balloon and surrounding tissues.

PubMed

Poon, Carmen C Y; Leung, Billy; Chan, Cecilia K W; Lau, James Y W; Chiu, Philip W Y

2016-02-01

The current design of capsule endoscope is limited by the inability to control the motion within gastrointestinal tract. The rising incidence of gastrointestinal cancers urged improvement in the method of screening endoscopy. This preclinical study aimed to design and develop a novel locomotive module for capsule endoscope. We investigated the feasibility and physical properties of this newly designed caterpillar-like capsule endoscope with a view to enhancing screening endoscopy. This study consisted of preclinical design and experimental testing on the feasibility of automated locomotion for a prototype caterpillar endoscope. The movement was examined first in the PVC tube and then in porcine intestine. The image captured was transmitted to handheld device to confirm the control of movement. The balloon pressure and volume as well as the contact force between the balloon and surroundings were measured when the balloon was inflated inside (1) a hard PVC tube, (2) a soft PVC tube, (3) muscular sites of porcine colons and (4) less muscular sites of porcine colons. The prototype caterpillar endoscope was able to move inward and backward within the PVC tubing and porcine intestine. Images were able to be captured from the capsule endoscope attached and being observed with a handheld device. Using the onset of a contact force as indication of the buildup of the gripping force between the balloon and the lumen walls, it is concluded from the results of this study that the rate of change in balloon pressure and volume is two good estimators to optimize the inflation of the balloon. The results of this study will facilitate further refinement in the design of caterpillar robotic endoscope to move inside the GI tract.

Development and Preliminary Application of High-Resolution Endoscopic Piv for Quantification of Flow Structure Within a Pore Space

NASA Astrophysics Data System (ADS)

Blois, G.; Sambrook Smith, G.; Best, J.; Hardy, R.; Lead, J.

2008-12-01

Most natural rivers have beds of loose, cohesionless sediment that form a porous bed, thus permitting significant interactions between the free flow above the bed and that within the pore spaces. Many unresolved problems in channel engineering and ecohydraulics are related to an incomplete understanding of this interstitial flow. For example, the mechanisms of pollutant transport and prediction of river bed morphodynamics may be strongly influenced by flow occurring within the pore spaces. While this lack of understanding has been widely acknowledged, the direct experimental investigation of flow within the pore spaces has been restricted by the practical difficulties in collecting such data. This has also created drawbacks in the numerical modeling of pore flow as there remains a dearth of robust experimental data with which to validate such models. In order to help address these issues, we present details of a new endoscopic PIV system designed to tackle some of the challenges highlighted above. The work presented in this paper is also being used to validate a numerical model that is being developed as part of this project. A fully endoscopic PIV system has been developed to collect velocity and turbulence data for flow within the pore space of a gravel bed. The system comprises a pulsed Nd:YAG laser that provides high intensity illumination for single exposure pairs of images on a high-resolution digital camera. The use of rigid endoscopes for both the laser light source and camera allows measurement of quasi-instantaneous flow fields by high-resolution PIV images (2352*1728 pixels). In the first instance, the endoscopic PIV system has been used to study flow within an artificial pore space model constructed from 38 and 51 mm diameter spheres, used to represent a simplified version of a natural gravel-bed river. Across-correlation processing approach has been applied to the PIV images and the processing parameters have been optimized for the experimental

Percutaneous cholecystolithotomy. A minimally invasive alternative to cholecystectomy and to shock wave lithotripsy.

PubMed

Griffith, D P; Gleeson, M J; Appel, M F; Bentlif, P S; Hochman, F L; Toombs, B D; Skolkin, M D

1990-09-01

Recently introduced treatment alternatives for gallstones include peroral pharmacological chemolysis plus shock wave lithotripsy and percutaneous cholecystolithotomy. Herein we report on the treatment preferences of 23 patients with symptomatic gallstones and our initial experience with percutaneous cholecystolithotomy in 6 of these patients. All patients were rendered stone free after one procedure. Percutaneous cholecystolithotomy, which is applicable to all types of gallstones, is a safe, practical, low-morbidity alternative to cholecystectomy in selected patients.

''Sandwich'' treatment for diospyrobezoar intestinal obstruction: A case report

PubMed Central

Zheng, Yi-Xiong; Prasoon, Pankaj; Chen, Yan; Hu, Liang; Chen, Li

2014-01-01

Intestinal obstruction is a common clinical entity encountered in surgical practice. The objective of this report is to corroborate an atypical scenario of intestinal obstruction in a Chinese patient and to focus on the diagnosis and treatment. A 27-year-old male presented with a history of gastric pain combined with nausea and abdominal distension that had been present for 5 d. The presence of a foreign body was detected by computed tomography and observed as an abnormal density within the stomach. A diospyrobezoar was revealed during gastroscopy, the extraction of which was prevented due to its size and firmness. An endoscopic holmium laser joined with a snare was used to fragment the obstruction, which was followed by management with a conservative “sandwich” treatment strategy involving intestinal decompression with an ileus tube and Coca-Cola lavage between endoscopic lithotripsy fragmentation procedures. This strategy resulted in the successful removal of the diospyrobezoar along with multiple small bowel obstructions. The patient was discharged after abatement of symptoms. The case presented here demonstrates the implementation of a conservative, yet successful, treatment as an alternative to conventional surgical removal of intestinal obstructions. PMID:25561823

Endoscopic full-thickness resection: Current status

PubMed Central

Schmidt, Arthur; Meier, Benjamin; Caca, Karel

2015-01-01

Conventional endoscopic resection techniques such as endoscopic mucosal resection or endoscopic submucosal dissection are powerful tools for treatment of gastrointestinal neoplasms. However, those techniques are restricted to superficial layers of the gastrointestinal wall. Endoscopic full-thickness resection (EFTR) is an evolving technique, which is just about to enter clinical routine. It is not only a powerful tool for diagnostic tissue acquisition but also has the potential to spare surgical therapy in selected patients. This review will give an overview about current EFTR techniques and devices. PMID:26309354

Endoscopic full-thickness resection: Current status.

PubMed

Schmidt, Arthur; Meier, Benjamin; Caca, Karel

2015-08-21

Conventional endoscopic resection techniques such as endoscopic mucosal resection or endoscopic submucosal dissection are powerful tools for treatment of gastrointestinal neoplasms. However, those techniques are restricted to superficial layers of the gastrointestinal wall. Endoscopic full-thickness resection (EFTR) is an evolving technique, which is just about to enter clinical routine. It is not only a powerful tool for diagnostic tissue acquisition but also has the potential to spare surgical therapy in selected patients. This review will give an overview about current EFTR techniques and devices.

Clinical relevance of endoscopic assessment of inflammation in ulcerative colitis: Can endoscopic evaluation predict outcomes?

PubMed Central

Mohammed, Noor; Subramanian, Venkataraman

2016-01-01

Ulcerative colitis (UC) is a chronic inflammatory bowel condition characterised by a relapsing and remitting course. Symptom control has been the traditional mainstay of medical treatment. It is well known that histological inflammatory activity persists despite adequate symptom control and absence of endoscopic inflammation. Current evidence suggests that presence of histological inflammation poses a greater risk of disease relapse and subsequent colorectal cancer risk. New endoscopic technologies hold promise for developing endoscopic markers of mucosal inflammation. Achieving endoscopic and histological remission appears be the future aim of medical treatments for UC. This review article aims to evaluate the use of endoscopy as a tool in assessment of mucosal inflammation UC and its correlation with disease outcomes. PMID:27895420

21 CFR 882.1480 - Neurological endoscope.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Neurological endoscope. 882.1480 Section 882.1480...) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Diagnostic Devices § 882.1480 Neurological endoscope. (a) Identification. A neurological endoscope is an instrument with a light source used to view the inside of the...

21 CFR 882.1480 - Neurological endoscope.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Neurological endoscope. 882.1480 Section 882.1480...) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Diagnostic Devices § 882.1480 Neurological endoscope. (a) Identification. A neurological endoscope is an instrument with a light source used to view the inside of the...

Endoscopic medial maxillectomy breaking new frontiers.

PubMed

Mohanty, Sanjeev; Gopinath, M

2013-07-01

Endoscopy has changed the perspective of rhinologist towards the nose. It has revolutionised the surgical management of sinonasal disorders. Sinus surgeries were the first to get the benefit of endoscope. Gradually the domain of endoscopic surgery extended to the management of sino nasal tumours. Traditionally medial maxillectomy was performed through lateral rhinotomy or mid facial degloving approach. Endoscopic medial maxillectomy has been advocated by a number of authors in the management of benign sino-nasal tumours. We present our experience of endoscopic medial maxillectomy in the management of sinonasal pathologies.

Analysis of the color rendition of flexible endoscopes

NASA Astrophysics Data System (ADS)

Murphy, Edward M.; Hegarty, Francis J.; McMahon, Barry P.; Boyle, Gerard

2003-03-01

Endoscopes are imaging devices routinely used for the diagnosis of disease within the human digestive tract. Light is transmitted into the body cavity via incoherent fibreoptic bundles and is controlled by a light feedback system. Fibreoptic endoscopes use coherent fibreoptic bundles to provide the clinician with an image. It is also possible to couple fibreoptic endoscopes to a clip-on video camera. Video endoscopes consist of a small CCD camera, which is inserted into gastrointestinal tract, and associated image processor to convert the signal to analogue RGB video signals. Images from both types of endoscope are displayed on standard video monitors. Diagnosis is dependent upon being able to determine changes in the structure and colour of tissues and biological fluids, and therefore is dependent upon the ability of the endoscope to reproduce the colour of these tissues and fluids with fidelity. This study investigates the colour reproduction of flexible optical and video endoscopes. Fibreoptic and video endoscopes alter image colour characteristics in different ways. The colour rendition of fibreoptic endoscopes was assessed by coupling them to a video camera and applying video colorimetric techniques. These techniques were then used on video endoscopes to assess how the colour rendition of video endoscopes compared with that of optical endoscopes. In both cases results were obtained at fixed illumination settings. Video endoscopes were then assessed with varying levels of illumination. Initial results show that at constant luminance endoscopy systems introduce non-linear shifts in colour. Techniques for examining how this colour shift varies with illumination intensity were developed and both methodology and results will be presented. We conclude that more rigorous quality assurance is required to reduce colour error and are developing calibration procedures applicable to medical endoscopes.

Endoscopic Gallbladder Drainage for Acute Cholecystitis

PubMed Central

Widmer, Jessica; Alvarez, Paloma; Sharaiha, Reem Z.; Gossain, Sonia; Kedia, Prashant; Sarkaria, Savreet; Sethi, Amrita; Turner, Brian G.; Millman, Jennifer; Lieberman, Michael; Nandakumar, Govind; Umrania, Hiren; Gaidhane, Monica

2015-01-01

Background/Aims Surgery is the mainstay of treatment for cholecystitis. However, gallbladder stenting (GBS) has shown promise in debilitated or high-risk patients. Endoscopic transpapillary GBS and endoscopic ultrasound-guided GBS (EUS-GBS) have been proposed as safe and effective modalities for gallbladder drainage. Methods Data from patients with cholecystitis were prospectively collected from August 2004 to May 2013 from two United States academic university hospitals and analyzed retrospectively. The following treatment algorithm was adopted. Endoscopic retrograde cholangiopancreatography (ERCP) with sphincterotomy and cystic duct stenting was initially attempted. If deemed feasible by the endoscopist, EUS-GBS was then pursued. Results During the study period, 139 patients underwent endoscopic gallbladder drainage. Among these, drainage was performed in 94 and 45 cases for benign and malignant indications, respectively. Successful endoscopic gallbladder drainage was defined as decompression of the gallbladder without incidence of cholecystitis, and was achieved with ERCP and cystic duct stenting in 117 of 128 cases (91%). Successful endoscopic gallbladder drainage was also achieved with EUS-guided gallbladder drainage using transmural stent placement in 11 of 11 cases (100%). Complications occurred in 11 cases (8%). Conclusions Endoscopic gallbladder drainage techniques are safe and efficacious methods for gallbladder decompression in non-surgical patients with comorbidities. PMID:26473125

Per-oral endoscopic myotomy: Major advance in achalasia treatment and in endoscopic surgery

PubMed Central

Friedel, David; Modayil, Rani; Stavropoulos, Stavros N

2014-01-01

Per-oral endoscopic myotomy (POEM) represents a natural orifice endoscopic surgery (NOTES) approach to laparoscopy Heller myotomy (LHM). POEM is arguably the most successful clinical application of NOTES. The growth of POEM from a single center in 2008 to approximately 60 centers worldwide in 2014 with several thousand procedures having been performed attests to the success of POEM. Initial efficacy, safety and acid reflux data suggest at least equivalence of POEM to LHM, the previous gold standard for achalasia therapy. Adjunctive techniques used in the West include impedance planimetry for real-time intraprocedural luminal assessment and endoscopic suturing for challenging mucosal defect closures during POEM. The impact of POEM extends beyond the realm of esophageal motility disorders as it is rapidly popularizing endoscopic submucosal dissection in the West and spawning offshoots that use the submucosal tunnel technique for a host of new indications ranging from resection of tumors to pyloromyotomy for gastroparesis. PMID:25548473

New Principles In Operating Gastro-Intestinal Tract With CO2 Laser

NASA Astrophysics Data System (ADS)

Skobelkin, O. K.; Litwin, G. D.; Smoljaninov, M. V.; Brehov, E. I.; Rjabov, V. I.; Kirpitchev, A. G.

1988-06-01

Laser devicea are becoming morn popular in surgery. They are mainly used for controling hemorrages through an endoscope, for radicalevaporating benign and small malignant tumors in esophagus, stomach, colon, and for palliative destruction of inoperable tumors to recanalize the lumen. According, to literature operations on abdominal parenchymal organs with laser are rather seldom. And the operations with laser on hollow organs of digestive tract are being mainly performed in the USSR, and they being rather effective.

Single incision endoscopic surgery for gynaecomastia.

PubMed

Jarrar, G; Peel, A; Fahmy, R; Deol, H; Salih, V; Mostafa, A

2011-09-01

Surgical excision has been an effective treatment for gynaecomastia. Recently, there has been a shift from the open approach to minimally invasive techniques. In this report we describe our technique which includes endoscopic excision and/or liposuction of gynaecomastia via a single lateral chest wall incision. Between May 2007 and April 2010, a total of 12 gynaecomastia patients were treated with liposuction and/or endoscopic excision. Patients were divided into 3 groups: group I; liposuction only, group II; endoscopic excision plus liposuction and group III; endoscopic excision only. One 15 mm incision was made laterally at the anterior axillary line. A vacuum assisted liposuction removing the fatty tissue was performed. Then endoscopic excision of the remaining fibroglandular tissue was done under vision through the same incision. The parynchyma was then dissected into small pieces and pulled out. Group I had liposuction only (n = 4), group II had liposuction combined with endoscopic excision (n = 7) (58%) while group III had endoscopic excision only (n = 1). The mean operative time for liposuction and endoscopic excision was 58 min for each side. Mean hospital stay was 1.4 days. Postoperative complications included infection with abscess formation and one patient had seroma. Mean follow-up was 56 weeks. Eleven out of twelve patients (92%) were satisfied with their results. Long-term follow-up showed that results were stable over time, and no revisions were necessary. Endoscopic excision of gynaecomastia through a single lateral chest wall incision is a minimally invasive effective and safe technique for the management of gynaecomastia, with excellent aesthetic results and an acceptable complication rate. Copyright © 2011 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Current Status of Peroral Endoscopic Myotomy

PubMed Central

Cho, Young Kwan; Kim, Seong Hwan

2018-01-01

Peroral endoscopic myotomy (POEM) has been established as an optional treatment for achalasia. POEM is an endoluminal procedure that involves dissection of esophageal muscle fibers followed by submucosal tunneling. Inoue first attempted to use POEM for the treatment of achalasia in humans. Expanded indications of POEM include classic indications such as type I, type II, type III achalasia, failed prior treatments, including Botulinum toxin injection, endoscopic balloon dilation, laparoscopic Heller myotomy, and hypertensive motor disorders such as diffuse esophageal spasm, jackhammer esophagus. Contraindications include prior radiation therapy to the esophagus and prior extensive esophageal mucosal resection/ablation involving the POEM field. Most of the complications are minor and self-limited and can be managed conservatively. As POEM emerged as the main treatment for achalasia, various adaptations to tunnel endoscopic surgery have been attempted. Tunnel endoscopic surgery includes POEM, peroral endoscopic tumor resection, gastric peroral endoscopic pyloromyotomy. POEM has been widely accepted as a treatment for all types of achalasia, even for specific cases such as achalasia with failed prior treatments, and hypertensive motor disorders. PMID:29397656

Current Status of Peroral Endoscopic Myotomy.

PubMed

Cho, Young Kwan; Kim, Seong Hwan

2018-01-01

Peroral endoscopic myotomy (POEM) has been established as an optional treatment for achalasia. POEM is an endoluminal procedure that involves dissection of esophageal muscle fibers followed by submucosal tunneling. Inoue first attempted to use POEM for the treatment of achalasia in humans. Expanded indications of POEM include classic indications such as type I, type II, type III achalasia, failed prior treatments, including Botulinum toxin injection, endoscopic balloon dilation, laparoscopic Heller myotomy, and hypertensive motor disorders such as diffuse esophageal spasm, jackhammer esophagus. Contraindications include prior radiation therapy to the esophagus and prior extensive esophageal mucosal resection/ablation involving the POEM field. Most of the complications are minor and self-limited and can be managed conservatively. As POEM emerged as the main treatment for achalasia, various adaptations to tunnel endoscopic surgery have been attempted. Tunnel endoscopic surgery includes POEM, peroral endoscopic tumor resection, gastric peroral endoscopic pyloromyotomy. POEM has been widely accepted as a treatment for all types of achalasia, even for specific cases such as achalasia with failed prior treatments, and hypertensive motor disorders.

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.

Investigations to improve laser induced lithrotripsy (Conference Presentation)

NASA Astrophysics Data System (ADS)

Eisel, Max; Ulaganathan, Keerthanan; Strittmatter, Frank; Pongratz, Thomas; Sroka, Ronald

2017-02-01

Laser lithotripsy is the preferred application for the destruction of ureteral and kidney stones. Clinically Ho:YAG lasers (λ=2.1μm) are used due to high absorption by water to induce thermomechanical ablation. This study focussed on the investigation of different laser parameters in relation to the stone dusting efficiency. The term dusting was defined when the ablated fragments were d<1mm in diameter while fragmentation is defined to pieces of d> 1mm. The discussion about fragment-size showed advantages like reduced surgery time. Experiments were performed using clinical available Ho:YAG laser energy transferred via a standard fibre (Ø: 365μm) onto phantom calculi (Bego-Stones of different hardness) in a water filled vessel. Dusting can be reached most efficient by using low energy/pulse (approx. 0.5J/pulse) and repetition rate of around 40 Hz. Higher energy/pulse showed strong repulsion and thereby increased mobility, while using lower repetition rates result in longer ablation times. With regard to the hardness of the phantoms it can be derived that on soft calculi or calculi with a very rugged surface dusting can be observed less because the stone breaks into large fragments after a short time of laser application. For hard calculi the ablation process takes a much longer time compared to soft stones. In the following will be shown that dusting and fragmentation process depends not only on the energy/pulse and repetition rate of a Ho:YAG-laser, but also there are differences between Ho:YAG-laser systems according to the dusting efficiency.

Esophageal-guided biopsy with volumetric laser endomicroscopy and laser cautery marking: a pilot clinical study.

PubMed

Suter, Melissa J; Gora, Michalina J; Lauwers, Gregory Y; Arnason, Thomas; Sauk, Jenny; Gallagher, Kevin A; Kava, Lauren; Tan, Khay M; Soomro, Amna R; Gallagher, Timothy P; Gardecki, Joseph A; Bouma, Brett E; Rosenberg, Mireille; Nishioka, Norman S; Tearney, Guillermo J

2014-06-01

Biopsy surveillance protocols for the assessment of Barrett's esophagus can be subject to sampling errors, resulting in diagnostic uncertainty. Optical coherence tomography is a cross-sectional imaging technique that can be used to conduct volumetric laser endomicroscopy (VLE) of the entire distal esophagus. We have developed a biopsy guidance platform that places endoscopically visible marks at VLE-determined biopsy sites. The objective of this study was to demonstrate in human participants the safety and feasibility of VLE-guided biopsy in vivo. A pilot feasibility study. Massachusetts General Hospital. A total of 22 participants were enrolled from January 2011 to June 2012 with a prior diagnosis of Barrett's esophagus. Twelve participants were used to optimize the laser marking parameters and the system platform. A total of 30 target sites were selected and marked in real-time by using the VLE-guided biopsy platform in the remaining 10 participants. Volumetric laser endomicroscopy. Endoscopic and VLE visibility, and accuracy of VLE diagnosis of the tissue between the laser cautery marks. There were no adverse events of VLE and laser marking. The optimal laser marking parameters were determined to be 2 seconds at 410 mW, with a mark separation of 6 mm. All marks made with these parameters were visible on endoscopy and VLE. The accuracies for diagnosing tissue in between the laser cautery marks by independent blinded readers for endoscopy were 67% (95% confidence interval [CI], 47%-83%), for VLE intent-to-biopsy images 93% (95% CI, 78%-99%), and for corrected VLE post-marking images 100% when compared with histopathology interpretations. This is a single-center feasibility study with a limited number of patients. Our results demonstrate that VLE-guided biopsy of the esophagus is safe and can be used to guide biopsy site selection based on the acquired volumetric optical coherence tomography imaging data. ( NCT01439633.). Copyright © 2014 American Society for

Esophageal-guided biopsy with volumetric laser endomicroscopy and laser cautery marking: a pilot clinical study

PubMed Central

Suter, Melissa J.; Gora, Michalina J.; Lauwers, Gregory Y.; Arnason, Thomas; Sauk, Jenny; Gallagher, Kevin A.; Kava, Lauren; Tan, Khay M.; Soomro, Amna R.; Gallagher, Timothy P.; Gardecki, Joseph A.; Bouma, Brett E.; Rosenberg, Mireille; Nishioka, Norman S.; Tearney, Guillermo J.

2018-01-01

Background Biopsy surveillance protocols for the assessment of Barrett’s esophagus can be subject to sampling errors, resulting in diagnostic uncertainty. Optical coherence tomography is a cross-sectional imaging technique that can be used to conduct volumetric laser endomicroscopy (VLE) of the entire distal esophagus. We have developed a biopsy guidance platform that places endoscopically visible marks at VLE-determined biopsy sites. Objective The objective of this study was to demonstrate in human participants the safety and feasibility of VLE-guided biopsy in vivo. Design A pilot feasibility study. Setting Massachusetts General Hospital. Patients A total of 22 participants were enrolled from January 2011 to June 2012 with a prior diagnosis of Barrett’s esophagus. Twelve participants were used to optimize the laser marking parameters and the system platform. A total of 30 target sites were selected and marked in real-time by using the VLE-guided biopsy platform in the remaining 10 participants. Intervention Volumetric laser endomicroscopy. Main Outcome Measurements Endoscopic and VLE visibility, and accuracy of VLE diagnosis of the tissue between the laser cautery marks. Results There were no adverse events of VLE and laser marking. The optimal laser marking parameters were determined to be 2 seconds at 410 mW, with a mark separation of 6 mm. All marks made with these parameters were visible on endoscopy and VLE. The accuracies for diagnosing tissue in between the laser cautery marks by independent blinded readers for endoscopy were 67% (95% confidence interval [CI], 47%–83%), for VLE intent-to-biopsy images 93% (95% CI, 78%–99%), and for corrected VLE post-marking images 100% when compared with histopathology interpretations. Limitations This is a single-center feasibility study with a limited number of patients. Conclusion Our results demonstrate that VLE-guided biopsy of the esophagus is safe and can be used to guide biopsy site selection based on the

A 3D scanning laser endoscope architecture utilizing a circular piezoelectric membrane

NASA Astrophysics Data System (ADS)

Khayatzadeh, Ramin; Çivitci, Fehmi; Ferhanoğlu, Onur

2017-12-01

A piezo-scanning fiber endoscopic device architecture is proposed for 3D imaging or ablation. The endoscopic device consists of a piezoelectric membrane that is placed perpendicular to the optical axis, a fiber optic cable that extends out from and actuated by the piezoelectric membrane, and one or multiple lenses for beam delivery and collection. Unlike its counterparts that utilize piezoelectric cylinders for fiber actuation, the proposed architecture offers quasi-static actuation in the axial direction along with resonant actuation in the lateral directions forming a 3D scanning pattern, allowing adjustment of the focus plane. The actuation of the four-quadrant piezoelectric membrane involves driving of two orthogonal electrodes with AC signals for lateral scanning, while simultaneously driving all electrodes for axial scanning and focus adjustment. We have characterized piezoelectric membranes (5 -15mm diameter) with varying sizes to monitor axial displacement behavior with respect to applied DC voltage. We also demonstrate simultaneous lateral and axial actuation on a resolution target, and observe the change of lateral resolution on a selected plane through performing 1D cross-sectional images, as an indicator of focal shift through axial actuation. Based on experimental results, we identify the optical and geometrical parameters for optimal 3D imaging of tissue samples. Our findings reveal that a simple piezoelectric membrane, having comparable dimensions and drive voltage requirement with off-the-shelf MEMS scanner chips, offers tissue epithelial imaging with sub-cellular resolution.

Endoscopic and non-endoscopic approaches for the management of radiation-induced rectal bleeding

PubMed Central

Weiner, Joseph Paul; Wong, Andrew Thomas; Schwartz, David; Martinez, Manuel; Aytaman, Ayse; Schreiber, David

2016-01-01

Pelvic radiation is a commonly utilized treatment for malignancy of the genitourinary and lower gastrointestinal tract. Radiation proctitis and the resultant clinical picture varies from asymptomatic to potentially life threatening. Similarly, treatment options also vary greatly, from medical therapy to surgical intervention. Commonly utilized medical therapy includes sucralfate enemas, antibiotics, 5-aminosalicylic acid derivatives, probiotics, antioxidants, short-chain fatty acids, formalin instillation and fractionated hyperbaric oxygen. More invasive treatments include endoscopic-based, focally ablative interventions such as dilation, heater and bipolar cautery, neodymium/yttrium aluminum garnet argon laser, radiofrequency ablation or argon plasma coagulation. Despite its relatively common frequency, there is a dearth of existing literature reporting head-to-head comparisons of the various treatment options via a randomized controlled approach. The purpose of our review was to present the reader a consolidation of the existing evidence-based literature with the goal of highlighting the comparative effectiveness and risks of the various treatment approaches. Finally, we outline a pragmatic approach to the treatment of radiation proctitis. In light of the lack of randomized data, our goal is to pursue as least invasive an approach as possible, with escalation of care tailored to the severity of the patient’s symptoms. For those cases that are clinically asymptomatic or only mildly symptomatic, observation or medical management can be considered. Once a patient fails such management or symptoms become more severe, invasive procedures such as endoscopically based focal ablation or surgical intervention can be considered. Although not all recommendations are supported by level I evidence, reported case series and single-institutional studies in the literature suggest that successful treatment with cessation of symptoms can be obtained in the majority of cases

Predictive Factors of Atelectasis Following Endoscopic Resection.

PubMed

Choe, Jung Wan; Jung, Sung Woo; Song, Jong Kyu; Shim, Euddeum; Choo, Ji Yung; Kim, Seung Young; Hyun, Jong Jin; Koo, Ja Seol; Yim, Hyung Joon; Lee, Sang Woo

2016-01-01

Atelectasis is one of the pulmonary complications associated with anesthesia. Little is known about atelectasis following endoscopic procedures under deep sedation. This study evaluated the frequency, risk factors, and clinical course of atelectasis after endoscopic resection. A total of 349 patients who underwent endoscopic resection of the upper gastrointestinal tract at a single academic tertiary referral center from March 2010 to October 2013 were enrolled. Baseline characteristics and clinical data were retrospectively reviewed from medical records. To identify atelectasis, we compared the chest radiography taken before and after the endoscopic procedure. Among the 349 patients, 68 (19.5 %) had newly developed atelectasis following endoscopic resection. In univariate logistic regression analysis, atelectasis correlated significantly with high body mass index, smoking, diabetes mellitus, procedure duration, size of lesion, and total amount of propofol. In multiple logistic regression analysis, body mass index, procedure duration, and total propofol amount were risk factors for atelectasis following endoscopic procedures. Of the 68 patients with atelectasis, nine patients developed fever, and six patients displayed pneumonic infiltration. The others had no symptoms related to atelectasis. The incidence of radiographic atelectasis following endoscopic resection was nearly 20 %. Obesity, procedural time, and amount of propofol were the significant risk factors for atelectasis following endoscopic procedure. Most cases of the atelectasis resolved spontaneously with no sequelae.

[Percutaneous endoscopic gastrostomy].

PubMed

Kuz'min-Krutetskiĭ, M I; Demko, A E; Safoev, A I; Akkalaeva, A É; Karimova, L I

2014-01-01

The percutaneous endoscopic gastrostomy takes an important place in operative endoscopy of the digestive system. At the same time it is the method of choice in patients who need a long-term administration of enteral feeding. Given article reflects the main indications, contraindications and complications of the percutaneous endoscopic gastrostomy and presents the basic stages of the method. The authors hope, that the data would be useful for both entry-lever surgeon-endoscopists and specialists who used the method.

Endoscopic management of hilar biliary strictures

PubMed Central

Singh, Rajiv Ranjan; Singh, Virendra

2015-01-01

Hilar biliary strictures are caused by various benign and malignant conditions. It is difficult to differentiate benign and malignant strictures. Postcholecystectomy benign biliary strictures are frequently encountered. Endoscopic management of these strictures is challenging. An endoscopic method has been advocated that involves placement of increasing number of stents at regular intervals to resolve the stricture. Malignant hilar strictures are mostly unresectable at the time of diagnosis and only palliation is possible.Endoscopic palliation is preferred over surgery or radiological intervention. Magnetic resonance cholangiopancreaticography is quite important in the management of these strictures. Metal stents are superior to plastic stents. The opinion is divided over the issue of unilateral or bilateral stenting.Minimal contrast or no contrast technique has been advocated during endoscopic retrograde cholangiopancreatography of these patients. The role of intraluminal brachytherapy, intraductal ablation devices, photodynamic therapy, and endoscopic ultrasound still remains to be defined. PMID:26191345

Endoscopes with latest technology and concept.

PubMed

Gotoh

2003-09-01

Endoscopic imaging systems that perform as the "eye" of the operator during endoscopic surgical procedures have developed rapidly due to various technological developments. In addition, since the most recent turn of the century robotic surgery has increased its scope through the utilization of systems such as Intuitive Surgical's da Vinci System. To optimize the imaging required for precise robotic surgery, a unique endoscope has been developed, consisting of both a two dimensional (2D) image optical system for wider observation of the entire surgical field, and a three dimensional (3D) image optical system for observation of the more precise details at the operative site. Additionally, a "near infrared radiation" endoscopic system is under development to detect the sentinel lymph node more readily. Such progress in the area of endoscopic imaging is expected to enhance the surgical procedure from both the patient's and the surgeon's point of view.

Endoscopic optical coherence tomography with a modified microelectromechanical systems mirror for detection of bladder cancers

NASA Astrophysics Data System (ADS)

Xie, Tuqiang; Xie, Huikai; Fedder, Gary K.; Pan, Yingtian

2003-11-01

Experimental results of a modified micromachined microelectromechanical systems (MEMS) mirror for substantial enhancement of the transverse laser scanning performance of endoscopic optical coherence tomography (EOCT) are presented. Image distortion due to buckling of MEMS mirror in our previous designs was analyzed and found to be attributed to excessive internal stress of the transverse bimorph meshes. The modified MEMS mirror completely eliminates bimorph stress and the resultant buckling effect, which increases the wobbling-free angular optical actuation to greater than 37°, exceeding the transverse laser scanning requirements for EOCT and confocal endoscopy. The new optical coherence tomography (OCT) endoscope allows for two-dimensional cross-sectional imaging that covers an area of 4.2 mm × 2.8 mm (limited by scope size) and at roughly 5 frames/s instead of the previous area size of 2.9 mm × 2.8 mm and is highly suitable for noninvasive and high-resolution imaging diagnosis of epithelial lesions in vivo. EOCT images of normal rat bladders and rat bladder cancers are compared with the same cross sections acquired with conventional bench-top OCT. The results clearly demonstrate the potential of EOCT for in vivo imaging diagnosis and precise guidance for excisional biopsy of early bladder cancers.

Endoscopic pancreatic necrosectomy.

PubMed

Fogel, Evan L

2011-07-01

Traditionally, patients with symptomatic sterile pancreatic necrosis or infected necrosis have been managed by open surgical debridement and removal of necrotic tissue. Within the last decade, however, reports of endoscopic pancreatic necrosectomy, an alternative minimally invasive approach, have demonstrated high success rates and low mortality rates. This report describes the indications, technique, and study outcome data of the procedure. While our experience with this technique has recently increased, better selection criteria are needed to identify patients who are most suitable for endoscopic therapy.

Advanced Endoscopic Navigation: Surgical Big Data, Methodology, and Applications.

PubMed

Luo, Xiongbiao; Mori, Kensaku; Peters, Terry M

2018-06-04

Interventional endoscopy (e.g., bronchoscopy, colonoscopy, laparoscopy, cystoscopy) is a widely performed procedure that involves either diagnosis of suspicious lesions or guidance for minimally invasive surgery in a variety of organs within the body cavity. Endoscopy may also be used to guide the introduction of certain items (e.g., stents) into the body. Endoscopic navigation systems seek to integrate big data with multimodal information (e.g., computed tomography, magnetic resonance images, endoscopic video sequences, ultrasound images, external trackers) relative to the patient's anatomy, control the movement of medical endoscopes and surgical tools, and guide the surgeon's actions during endoscopic interventions. Nevertheless, it remains challenging to realize the next generation of context-aware navigated endoscopy. This review presents a broad survey of various aspects of endoscopic navigation, particularly with respect to the development of endoscopic navigation techniques. First, we investigate big data with multimodal information involved in endoscopic navigation. Next, we focus on numerous methodologies used for endoscopic navigation. We then review different endoscopic procedures in clinical applications. Finally, we discuss novel techniques and promising directions for the development of endoscopic navigation.

Endoscopic papillectomy: indications, techniques, and results.

PubMed

De Palma, Giovanni D

2014-02-14

Endoscopic papillectomy (EP) is currently accepted as a viable alternative therapy to surgery in sporadic ampullary adenoma and has been reported to have high success and low recurrence rates. At present, the indications for EP are not yet fully established. The accepted criteria for EP include size (up to 5 cm), no evidence of intraductal growth, and no evidence of malignancy on endoscopic findings (ulceration, friability, and spontaneous bleeding). Endoscopic ultrasound (EUS) is the imaging modality of choice for local T staging in ampullary neoplasms. Data reported in the literature have revealed that linear EUS is superior to helical computed tomography in the preoperative assessment of tumor size, detection of regional nodal metastases and detection of major vascular invasion. Endoscopic ampullectomy is performed using a standard duodenoscope in a similar manner to snare polypectomy of a mucosal lesion. There is no standardization of the equipment or technique and broad EP methods are described. Endoscopic ampullectomy is considered a ''high-risk'' procedure due to complications. Complications of endoscopic papillectomy can be classified as early (pancreatitis, bleeding, perforation, and cholangitis) and late (papillary stenosis) complications. The appropriate use of stenting after ampullectomy may prevent post-procedural pancreatitis and papillary stenosis. Tumor recurrence of benign lesions occurs in up to 20% of patients and depends on tumor size, final histology, presence of intraductal tumor, coexisting familial adenomatous polyposis (FAP), and the expertise of the endoscopist. Recurrent lesions are usually benign and most can be retreated endoscopically.

A novel integration of spectral-domain optical-coherence-tomography and laser-ablation system for precision treatment.

PubMed

Fan, Yingwei; Zhang, Boyu; Chang, Wei; Zhang, Xinran; Liao, Hongen

2018-03-01

Complete resection of diseased lesions reduces the recurrence of cancer, making it critical for surgical treatment. However, precisely resecting residual tumors is a challenge during operation. A novel integrated spectral-domain optical-coherence-tomography (SD-OCT) and laser-ablation therapy system for soft-biological-tissue resection is proposed. This is a prototype optical integrated diagnosis and therapeutic system as well as an optical theranostics system. We develop an optical theranostics system, which integrates SD-OCT, a laser-ablation unit, and an automatic scanning platform. The SD-OCT image of biological tissue provides an intuitive and clear view for intraoperative diagnosis and monitoring in real time. The effect of laser ablation is analyzed using a quantitative mathematical model. The automatic endoscopic scanning platform combines an endoscopic probe and an SD-OCT sample arm to provide optical theranostic scanning motion. An optical fiber and a charge-coupled device camera are integrated into the endoscopic probe, allowing detection and coupling of the OCT-aiming beam and laser spots. The integrated diagnostic and therapeutic system combines SD-OCT imaging and laser-ablation modules with an automatic scanning platform. OCT imaging, laser-ablation treatment, and the integration and control of diagnostic and therapeutic procedures were evaluated by performing phantom experiments. Furthermore, SD-OCT-guided laser ablation provided precision laser ablation and resection for the malignant lesions in soft-biological-tissue-lesion surgery. The results demonstrated that the appropriate laser-radiation power and duration time were 10 W and 10 s, respectively. In the laser-ablation evaluation experiment, the error reached approximately 0.1 mm. Another validation experiment was performed to obtain OCT images of the pre- and post-ablated craters of ex vivo porcine brainstem. We propose an optical integrated diagnosis and therapeutic system. The primary

Gynaecological endoscopic surgical education and assessment. A diploma programme in gynaecological endoscopic surgery.

PubMed

Campo, Rudi; Wattiez, Arnaud; Tanos, Vasilis; Di Spiezio Sardo, Attilio; Grimbizis, Grigoris; Wallwiener, Diethelm; Brucker, Sara; Puga, Marco; Molinas, Roger; O'Donovan, Peter; Deprest, Jan; Van Belle, Yves; Lissens, Ann; Herrmann, Anja; Tahir, Mahmood; Benedetto, Chiara; Siebert, Igno; Rabischong, Benoit; De Wilde, Rudy Leon

In recent years, training and education in endoscopic surgery has been critically reviewed. Clinicians, both surgeons as gynaecologist who perform endoscopic surgery without proper training of the specific psychomotor skills, are at higher risk to increased patient morbidity and mortality. Although the apprentice-tutor model has long been a successful approach for training of surgeons, recently, clinicians have recognised that endoscopic surgery requires an important training phase outside the operating theatre. The Gynaecological Endoscopic Surgical Education and Assessment programme (GESEA) recognises the necessity of this structured approach and implements two separated stages in its learning strategy. In the first stage, a skill certificate on theoretical knowledge and specific practical psychomotor skills is acquired through a high-stake exam; in the second stage, a clinical programme is completed to achieve surgical competence and receive the corresponding diploma. Three diplomas can be awarded: (a) the Bachelor in Endoscopy, (b) the Minimally Invasive Gynaecological Surgeon (MIGS) and (c) the Master level. The Master level is sub-divided into two separate diplomas: the Master in Laparoscopic Pelvic Surgery and the Master in Hysteroscopy. The complexity of modern surgery has increased the demands and challenges to surgical education and the quality control. This programme is based on the best available scientific evidence, and it counteracts the problem of the traditional surgical apprentice-tutor model. It is seen as a major step toward standardisation of endoscopic surgical training in general.

Gynaecological Endoscopic Surgical Education and Assessment. A diploma programme in gynaecological endoscopic surgery.

PubMed

Campo, Rudi; Wattiez, Arnaud; Tanos, Vasilis; Di Spiezio Sardo, Attilio; Grimbizis, Grigoris; Wallwiener, Diethelm; Brucker, Sara; Puga, Marco; Molinas, Roger; O'Donovan, Peter; Deprest, Jan; Van Belle, Yves; Lissens, Ann; Herrmann, Anja; Tahir, Mahmood; Benedetto, Chiara; Siebert, Igno; Rabischong, Benoit; De Wilde, Rudy Leon

2016-04-01

In recent years, training and education in endoscopic surgery has been critically reviewed. Clinicians, both surgeons as gynaecologist who perform endoscopic surgery without proper training of the specific psychomotor skills are at higher risk to increased patient morbidity and mortality. Although the apprentice-tutor model has long been a successful approach for training of surgeons, recently, clinicians have recognised that endoscopic surgery requires an important training phase outside the operating theatre. The Gynaecological Endoscopic Surgical Education and Assessment programme (GESEA), recognises the necessity of this structured approach and implements two separated stages in its learning strategy. In the first stage, a skill certificate on theoretical knowledge and specific practical psychomotor skills is acquired through a high stake exam; in the second stage, a clinical programme is completed to achieve surgical competence and receive the corresponding diploma. Three diplomas can be awarded: (a) the Bachelor in Endoscopy; (b) the Minimally Invasive Gynaecological Surgeon (MIGS); and (c) the Master level. The Master level is sub-divided into two separate diplomas: the Master in Laparoscopic Pelvic Surgery and the Master in Hysteroscopy. The complexity of modern surgery has increased the demands and challenges to surgical education and the quality control. This programme is based on the best available scientific evidence and it counteracts the problem of the traditional surgical apprentice tutor model. It is seen as a major step toward standardization of endoscopic surgical training in general. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Optic nerve sheath fenestration using a Raman-shifted alexandrite laser

PubMed Central

Kozub, John; Shen, Jin-H.; Joos, Karen M.; Prasad, Ratna; Hutson, M. Shane

2016-01-01

Background and Objective Optic nerve sheath fenestration is an established procedure for relief of potentially damaging overpressure on the optic nerve resulting from idiopathic intracranial hypertension. Prior work showed that a mid-IR free-electron laser could be delivered endoscopically and used to produce an effective fenestration. This study evaluates the efficacy of fenestration using a table-top mid-IR source based on a Raman-shifted alexandrite (RSA) laser. Study Design/Materials and Methods Porcine optic nerves were ablated using light from an RSA laser at wavelengths of 6.09, 6.27 and 6.43 μm and pulse energies up to 3 mJ using both free-space and endoscopic beam delivery through 250-μm I.D. hollow-glass waveguides. Waveguide transmission was characterized, ablation thresholds and etch rates were measured, and the efficacy of endoscopic fenestration was evaluated for ex vivo exposures using both optical coherence tomography and histological analysis. Results Using endoscopic delivery, the RSA laser can effectively fenestrate porcine optic nerves. Performance was optimized at a wavelength of 6.09 μm and delivered pulse energies of 0.5-0.8 mJ (requiring 1.5-2.5 mJ to be incident on the waveguide). Under these conditions, the ablation threshold fluence was 0.8 ± 0.2 J/cm2, the ablation rate was 1-4 μm/pulse, and the margins of ablation craters showed little evidence of thermal or mechanical damage. Nonetheless, nominally identical exposures yielded highly variable ablation rates. This led to fenestrations that ranged from too deep to too shallow – either damaging the underlying optic nerve or requiring additional exposure to cut fully through the sheath. Of 48 excised nerves subjected to fenestration at 6.09 μm, 16 ex vivo fenestrations were judged as good, 23 as too deep, and 9 as too shallow. Conclusions Mid-IR pulses from the RSA laser, propagated through a flexible hollow waveguide, are capable of cutting through porcine optic nerve sheaths in

Catheter-based photoacoustic endoscope

PubMed Central

Yang, Joon-Mo; Li, Chiye; Chen, Ruimin; Zhou, Qifa; Shung, K. Kirk; Wang, Lihong V.

2014-01-01

Abstract. We report a flexible shaft-based mechanical scanning photoacoustic endoscopy (PAE) system that can be potentially used for imaging the human gastrointestinal tract via the instrument channel of a clinical video endoscope. The development of such a catheter endoscope has been an important challenge to realize the technique’s benefits in clinical settings. We successfully implemented a prototype PAE system that has a 3.2-mm diameter and 2.5-m long catheter section. As the instrument’s flexible shaft and scanning tip are fully encapsulated in a plastic catheter, it easily fits within the 3.7-mm diameter instrument channel of a clinical video endoscope. Here, we demonstrate the intra-instrument channel workability and in vivo animal imaging capability of the PAE system. PMID:24887743

Step-by-step strategy in the management of residual hepatolithiasis using post-operative cholangioscopy

PubMed Central

Wen, Xu-dong; Wang, Tao; Huang, Zhu; Zhang, Hong-jian; Zhang, Bing-yin; Tang, Li-jun; Liu, Wei-hui

2017-01-01

Hepatolithiasis is the presence of calculi within the intrahepatic bile duct specifically located proximal to the confluence of the left and right hepatic ducts. The ultimate goal of hepatolithiasis treatment is the complete removal of the stone, the correction of the associated strictures and the prevention of recurrent cholangitis. Although hepatectomy could effectively achieve the above goals, it can be restricted by the risk of insufficient residual liver volume, and has a 15.6% rate of residual hepatolithiasis. With improvements in minimally invasive surgery, post-operative cholangioscopy (POC), provides an additional option for hepatolithiasis treatment with higher clearance rate and fewer severe complications. POC is very safe, and can be performed repeatedly until full patient benefit is achieved. During POC three main steps are accomplished: first, the analysis of the residual hepatolithiasis distribution indirectly by imaging methods or directly endoscopic observation; second, the establishment of the surgical pathway to relieve the strictures; and third, the removal of the stone by a combination of different techniques such as simple basket extraction, mechanical fragmentation, electrohydraulic lithotripsy or laser lithotripsy, among others. In summary, a step-by-step strategy of POC should be put forward to standardize the procedures, especially when dealing with complicated residual hepatolithiasis. This review briefly summarizes the classification, management and complications of hepatolithiasis during the POC process. PMID:29147136

Infrared glass fiber cables for CO laser medical applications

NASA Astrophysics Data System (ADS)

Arai, Tsunenori; Mizuno, Kyoichi; Sensaki, Koji; Kikuchi, Makoto; Watanabe, Tamishige; Utsumi, Atsushi; Takeuchi, Kiyoshi; Akai, Yoshiro

1993-05-01

We developed the medical fiber cables which were designed for CO laser therapy, i.e., angioplasty and endoscopic therapy. As-S chalcogenide glass fibers were used for CO laser delivery. A 230 micrometers core-diameter fiber was used for the angioplasty laser cable. The outer diameter of this cable was 600 micrometers . The total length and insertion length of the angioplasty laser cable were 2.5 m and 1.0 m, respectively. Typically, 2.0 W of fiber output was used in the animal experiment in vivo for the ablation of the model plaque which consisted of human atheromatous aorta wall. The transmission of the angioplasty laser cable was approximately 35%, because the reflection loss occurred at both ends of the fiber and window. Meanwhile, the core diameter of the energy delivery fiber for the endoscopic therapy was 450 micrometers . The outer diameter of this cable was 1.7 mm. Approximately 4.5 W of fiber output was used for clinical treatment of pneumothorax through a pneumoscope. Both types of the cables had the ultra-thin thermocouples for temperature monitoring at the tip of the cables. This temperature monitoring was extremely useful to prevent the thermal destruction of the fiber tip. Moreover, the As-S glass fibers were completely sealed by the CaF2 windows and outer tubes. Therefore, these cables were considered to have sufficient safety properties for medical applications. These laser cables were successfully used for the in vivo animal experiments and/or actual clinical therapies.

Effect of endoscopic transpapillary biliary drainage with/without endoscopic sphincterotomy on post-endoscopic retrograde cholangiopancreatography pancreatitis in patients with biliary stricture (E-BEST): a protocol for a multicentre randomised controlled trial

PubMed Central

Kato, Shin; Kuwatani, Masaki; Sugiura, Ryo; Sano, Itsuki; Kawakubo, Kazumichi; Ono, Kota; Sakamoto, Naoya

2017-01-01

Introduction The effect of endoscopic sphincterotomy prior to endoscopic biliary stenting to prevent post-endoscopic retrograde cholangiopancreatography pancreatitis remains to be fully elucidated. The aim of this study is to prospectively evaluate the non-inferiority of non-endoscopic sphincterotomy prior to stenting for naïve major duodenal papilla compared with endoscopic sphincterotomy prior to stenting in patients with biliary stricture. Methods and analysis We designed a multicentre randomised controlled trial, for which we will recruit 370 patients with biliary stricture requiring endoscopic biliary stenting from 26 high-volume institutions in Japan. Patients will be randomly allocated to the endoscopic sphincterotomy group or the non-endoscopic sphincterotomy group. The main outcome measure is the incidence of pancreatitis within 2 days of initial transpapillary biliary drainage. Data will be analysed on completion of the study. We will calculate the 95% confidence intervals (CIs) of the incidence of pancreatitis in each group and analyse weather the difference in both groups with 95% CIs is within the non-inferiority margin (6%) using the Wald method. Ethics and dissemination This study has been approved by the institutional review board of Hokkaido University Hospital (IRB: 016–0181). Results will be submitted for presentation at an international medical conference and published in a peer-reviewed journal. Trial registration number The University Hospital Medical Information Network ID: UMIN000025727 Pre-results. PMID:28801436

A novel robotic platform for laser-assisted transurethral surgery of the prostate.

PubMed

Russo, S; Dario, P; Menciassi, A

2015-02-01

Benign prostatic hyperplasia (BPH) is the most common pathology afflicting ageing men. The gold standard for the surgical treatment of BPH is transurethral resection of the prostate. The laser-assisted transurethral surgical treatment of BPH is recently emerging as a valid clinical alternative. Despite this, there are still some issues that hinder the outcome of laser surgery, e.g., distal dexterity is strongly reduced by the current endoscopic instrumentation and contact between laser and prostatic tissue cannot be monitored and optimized. This paper presents a novel robotic platform for laser-assisted transurethral surgery of BPH. The system, designed to be compatible with the traditional endoscopic instrumentation, is composed of a catheter-like robot provided with a fiber optic-based sensing system and a cable-driven actuation mechanism. The sensing system allows contact monitoring between the laser and the hypertrophic tissue. The actuation mechanism allows steering of the laser fiber inside the prostatic urethra of the patient, when contact must be reached. The design of the proposed robotic platform along with its preliminary testing and evaluation is presented in this paper. The actuation mechanism is tested in in vitro experiments to prove laser steering performances according to the clinical requirements. The sensing system is calibrated in experiments aimed to evaluate the capability of discriminating the contact forces, between the laser tip and the prostatic tissue, from the pulling forces exerted on the cables, during laser steering. These results have been validated demonstrating the robot's capability of detecting sub-Newton contact forces even in combination with actuation.