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Sample records for endoscopic laser lithotripsy

  1. Endoscopically controlled laser lithotripsy of sialoliths

    NASA Astrophysics Data System (ADS)

    Gundlach, Peter; Hopf, Juergen U. G.; Linnarz, Marietta; Leege, Nils; Scherer, Hans H.; Tschepe, Johannes; Mueller, Gerhard J.

    1992-08-01

    Among the diseases of the major salivary glands, sialolithiasis is a frequent clinical picture. Until now the condition has nearly always had to be treated surgically. In rare cases, discharge can be achieved by acid stimulation of secretion. If located distally in the excretory duct, concrements may be removed by enoral lancing. If it is close to glands, e.g., in the knee of Wharton's duct or in the ductal part of the submandibular gland, extirpation of the gland including the stone is unavoidable. Besides wound healing problems and the occurrence of salivary fistulas, the main risk of surgery is injury to the nerves around the major salivary glands, e.g., the n. facialis or one of its branches, the n. hypoglossus, or the n. lingualis with consecutive paresis. Based on the clinical results of lithotripsy by laser-induced shock waves (LIL) applied to renal stones and ureteroliths as well as bilary duct and pancreas stones, we investigated the suitability of endoscopically controlled laser therapy for sialolithiasis.

  2. Lithotripsy

    MedlinePlus

    ... have, their size, and where in your urinary system they are. Most of the time, lithotripsy removes all the stones. Alternative Names Extracorporeal shock wave lithotripsy; Shock wave lithotripsy; Laser lithotripsy; Percutaneous lithotripsy; Endoscopic lithotripsy; ESWL; Renal calculi- ...

  3. Kidney stones - lithotripsy - discharge

    MedlinePlus

    Extracorporeal shock wave lithotripsy - discharge; Shock wave lithotripsy - discharge; Laser lithotripsy - discharge; Percutaneous lithotripsy - discharge; Endoscopic lithotripsy - discharge; ESWL - discharge

  4. Lithotripsy

    MedlinePlus

    ... Laser lithotripsy; Percutaneous lithotripsy; Endoscopic lithotripsy; ESWL; Renal calculi-lithotripsy ... Lingeman JE. Surgical management of upper urinary tract calculi. In: Wein AJ, ed. Campbell-Walsh Urology . 10th ...

  5. Percutaneous Endoscopic Holmium Laser Lithotripsy for Management of Complicated Biliary Calculi

    PubMed Central

    Healy, Kelly; Chamsuddin, Abbas; Spivey, James; Martin, Louis; Nieh, Peter

    2009-01-01

    Background and Objectives: Advances in endoscopic techniques have transformed the management of urolithiasis. We sought to evaluate the role of such urological interventions for the treatment of complex biliary calculi. Methods: We conducted a retrospective review of all patients (n=9) undergoing percutaneous holmium laser lithotripsy for complicated biliary calculi over a 4-year period (12/2003 to 12/2007). All previously failed standard techniques include ERCP with sphincterotomy (n=6), PTHC (n=7), or both of these. Access to the biliary system was obtained via an existing percutaneous transhepatic catheter or T-tube tracts. Endoscopic holmium laser lithotripsy was performed via a flexible cystoscope or ureteroscope. Stone clearance was confirmed intra- and postoperatively. A percutaneous transhepatic drain was left indwelling for follow-up imaging. Results: Mean patient age was 65.6 years (range, 38 to 92). Total stone burden ranged from 1.7 cm to 5 cm. All 9 patients had stones located in the CBD, with 2 patients also having additional stones within the hepatic ducts. All 9 patients (100%) were visually stone-free after one endoscopic procedure. No major perioperative complications occurred. Mean length of stay was 2.4 days. At a mean radiological follow-up of 5.4 months (range, 0.5 to 21), no stone recurrence was noted. Conclusions: Percutaneous endoscopic holmium laser lithotripsy is a minimally invasive alternative to open salvage surgery for complex biliary calculi refractory to standard approaches. This treatment is both safe and efficacious. Success depends on a multidisciplinary approach. PMID:19660213

  6. Percutaneous Transhepatic Endoscopic Holmium Laser Lithotripsy for Intrahepatic and Choledochal Biliary Stones

    SciTech Connect

    Rimon, Uri; Kleinmann, Nir; Bensaid, Paul; Golan, Gil; Garniek, Alexander; Khaitovich, Boris; Winkler, Harry

    2011-12-15

    Purpose: To report our approach for treating complicated biliary calculi by percutaneous transhepatic endoscopic biliary holmium laser lithotripsy (PTBL). Patients and Methods: Twenty-two symptomatic patients (11 men and 11 women, age range 51 to 88 years) with intrahepatic or common bile duct calculi underwent PTBL. Nine patients had undergone previous gastrectomy and small-bowel anastomosis, thus precluding endoscopic retrograde cholangiopancreatography. In the other 13 patients, stone removal attempts by ERCP failed due to failed access or very large calculi. We used a 7.5F flexible ureteroscope and a 200-{mu}m holmium laser fiber by way of a percutaneous transhepatic tract, with graded fluoroscopy, to fragment the calculi with direct vision. Balloon dilatation was added when a stricture was seen. The procedure was performed with the patient under general anaesthesia. A biliary drainage tube was left at the end of the procedure. Results: All stones were completely fragmented and flushed into the small bowel under direct vision except for one patient in whom the procedure was aborted. In 18 patients, 1 session sufficed, and in 3 patients, 2 sessions were needed. In 7 patients, balloon dilatation was performed for benign stricture after Whipple operation (n = 3), for choledochalenteric anastomosis (n = 3), and for recurrent cholangitis (n = 1). Adjunctive 'balloon push' (n = 4) and 'rendezvous' (n = 1) procedures were needed to completely clean the biliary tree. None of these patients needed surgery. Conclusion: Complicated or large biliary calculi can be treated successfully using PTBL. We suggest that this approach should become the first choice of treatment before laparoscopic or open surgery is considered.

  7. A comparison of efficacies of holmium YAG laser, and pneumatic lithotripsy in the endoscopic treatment of ureteral stones

    PubMed Central

    Akdeniz, Ekrem; İrkılata, Lokman; Demirel, Hüseyin Cihan; Saylık, Acun; Bolat, Mustafa Suat; Şahinkaya, Necmettin; Zengin, Mehmet; Atilla, Mustafa Kemal

    2014-01-01

    Objective: We aimed to compare the effectiveness of holmium YAG laser and pneumatic lithotripsy in the treatment of ureteral stones. Material and methods: A total of 216 patients who had established indications of ureteroscopy between November 2011 and June 2012 were included in this study. Patients’ files were retrospectively reviewed by dividing cases as groups that underwent pneumatic (PL) or laser lithotripsy (LL) procedures. Age, sex, stone burden and localization, duration of follow-up, operative times were evaluated. Stone-free rates were evaluated by ureteroscopical examination, postoperative scout films and ultrasonography. Results: Group PL consisted of 109 and group LL of 107 patients. Median age was 43.93±15.94 years in Group PL and 46.15±14.54 years in Group LL. Male to female ratio, stone burden and localization were similar for both groups. Overall success rate was 89.9% in Group PL and 87.9% in Group LL, respectively (p<0.791). With the aid of additional procedures, success rate was 100% for both groups at the end of the first month. Groups were not different as for operative time, rate of insertion of an ureteral catheter and its removal time. Hospitalization period was apparently somewhat shorter in Group LL (p=0.00). Conclusion: Pneumatic lithotripsy can be as efficacious as laser lithotripsy and be used safely in the endoscopic management of ureteral stone. In comparison of both methods, we detected no differences as to operative time, success of operation and the time to removal of the catheter, however, hospitalization period was shorter in Group LL. PMID:26328167

  8. Laser lithotripsy with a Q-switched alexandrite laser system

    NASA Astrophysics Data System (ADS)

    Uebelacker, Walter

    1992-06-01

    The laser lithotripsy of ureter stones with the Alexan Triptor was introduced into urology in 1989. Pulsenergy, pulsewidth, wavelength, fiber performance, and endoscope performance are important parameters for effective stone disintegration.

  9. Comparison of different pulsed and Q-switched solid state laser systems for endoscopic laser-induced shockwave lithotripsy: performance and laser/stone interactions

    NASA Astrophysics Data System (ADS)

    Steiger, Erwin

    1990-06-01

    At present the laser induced shock wave lithotripsy (LISL) of urinary and biliary stones via fiber optic beam delivery is governed by two competing' laser systems: The flashlamp-pumped pulsed dye laser and the Q-switched Nd:YAG laser. The pulsed radiation of the dye system with pulse durations in the 1-2 .tsec region can be easily transmitted through extremely flexible fused silica fibers with core diameters of only 200 im whilst the Q-switched Nd:YAG laser with pulselengths of 5-25 nsec needs fibers with more than 400 tm core diameter. The dye laser releases acoustic shock waves for fragmentation simply by stone contact, the Q-switched Nd:YAG produces these waves in the surrounding aqueous medium by laser induced optical breakdown (LIB) when refocused by optical means or through additional metal absorbers, i.e. opto - mechanical couplers. We report on the system performances and laser/stone interactions of two alternative solid-state laser systems with variable pulselengths in the range of 1.7 - 30 sec and 30 - 1000 nsec, respectively: The pulsed psec-Nd:YAG laser and the Q-switched alexandrite laser. Regarding the endoscopic laser lithotripsy of urinary and biliary stones in the ureter or common bile duct, respectively, the laser energy delivery system, i.e. the optical fiber; is the most stressed part. Therefore we used long-pulse solid-state laser systems like the pulsed Nd:YAG laser with a pulse-slicing unit and a pulselength-tunable Q-switched alexandrite laser and studied fragmentation of synthetic plaster samples as well as urinary and biliary stones. The radiation of both laser systems can be effectively transmitted via standard 200 im core diameter optical quartz fibers what is absolutely necessary when used in conjunction with small caliber rigid or flexible endoscopes. As a compact and reliable solid-state system the alexandrite laser lithotripter is much less expensive than an extracorporeal shock wave lithotripter with the same fragmentation results

  10. Thulium Fiber Laser lithotripsy

    NASA Astrophysics Data System (ADS)

    Blackmon, Richard Leious, Jr.

    The Thulium Fiber Laser (TFL) has been studied as a potential alternative to the conventional Holmium:YAG laser (Ho:YAG) for the treatment of kidney stones. The TFL is more ideally suited for laser lithotripsy because of the higher absorption coefficient of the emitted wavelength in water, the superior Gaussian profile of the laser beam, and the ability to operate at arbitrary temporal pulse profiles. The higher absorption of the TFL by water helps translate into higher ablation of urinary stones using less energy. The Gaussian spatial beam profile allows the TFL to couple into fibers much smaller than those currently being used for Ho:YAG lithotripsy. Lastly, the ability of arbitrary pulse operation by the TFL allows energy to be delivered to the stone efficiently so as to avoid negative effects (such as burning or bouncing of the stone) while maximizing ablation. Along with these improvements, the unique properties of the TFL have led to more novel techniques that have currently not been used in the clinic, such as the ability to control the movement of stones based on the manner in which the laser energy is delivered. Lastly, the TFL has led to the development of novel fibers, such as the tapered fiber and removable tip fiber, to be used for lithotripsy which can lead to safer and less expensive treatment of urinary stones. Overall, the TFL has been demonstrated as a viable alternative to the conventional Ho:YAG laser and has the potential to advance methods and tools for treatment of kidney stones.

  11. Endoscopically-controlled electrohydraulic intracorporeal shock wave lithotripsy (EISL) of salivary stones.

    PubMed

    Königsberger, R; Feyh, J; Goetz, A; Kastenbauer, E

    1993-02-01

    Twenty-nine patients with salivary stones were treated with the endoscopically-controlled electrohydraulic shock wave lithotripsy (EISL). This new minimally invasive treatment of sialolithiasis is performed under local anesthesia on an outpatient basis with little inconvenience to the patient. For endoscopy, a flexible fibroscope with an additional probe to generate shock waves is placed into the submandibular duct and advanced until the stone is identified. For shock wave-induced stone disintegration, the probe electrode must be placed 1 mm in front of the concrement. The shock waves are generated by a sparkover at the tip of the probe. By means of the endoscopically-controlled shock wave lithotripsy it was possible to achieve complete stone fragmentation in 20 out of 29 patients without serious side effects. In three patients, only partial stone fragmentation could be achieved due to the stone quality. Endoscopically-controlled electrohydraulic intracorporeal shock wave lithotripsy represents a novel minimally invasive therapy for endoscopically accessible salivary gland stones. The advantage in comparison to the endoscopically-controlled laser lithotripsy will be discussed. PMID:8445694

  12. Spectroscopy During Laser Induced Shock Wave Lithotripsy

    NASA Astrophysics Data System (ADS)

    Engelhardt, R.; Meyer, W.; Hering, P.

    1988-06-01

    In the course of laser induced shock wave lithotripsy (LISL) by means of a flashlamp pumped dye laser a plasma is formed on the stone's surface. Spectral analysis of the plasma flash leads to chemical stone analysis during the procedure. A time resolved integral analysis of scattered and laser induced fluorescence light makes stone detection possible and avoids tissue damage. We used a 200 μm fiber to transmit a 2 μs, 50 mJ pulse to the stone's surface and a second 200 μ fiber for analysis. This transmission system is small and flexible enough for controlled endoscopic use in the treatment of human ureter or common bile duct stones. Under these conditions the stone selective effect of lasertripsy leads only to minor tissue injury.

  13. Fragmentation methods in laser lithotripsy

    NASA Astrophysics Data System (ADS)

    Jiang, Zhi X.; Whitehurst, Colin; King, Terence A.

    1991-07-01

    Following a series of opto-acoustic-mechanical and spectroscopic studies into the basic mechanisms of laser lithotripsy, a plasma-mediated opto-mechanical energy transfer model is presented. Laser energy, first absorbed by the calculi material at the surface and couples into the initiated plasma following ionization of vaporized material, is finally transformed into destructive mechanical energy via a shock wave induced by the impulsive expansion of the resulting plasma. This leads to the fragmentation of the calculi. The laser-plasma energy coupling gives a new definition for the fluence threshold to laser induced breakdown, which agrees with shock wave detection and analysis. A laser pulse shape with initial low intensity and sufficient fluence to vaporize a required amount of target material (lasting a few microsecond(s) ) and terminating in a short, intense pulse of about 1microsecond(s) or less, to couple most of the laser energy into the dense young plasma and so create high pressures, is required to produce optimum effect for laser lithotripsy. An opto-mechanical coupler has been designed which transfers the maximum laser energy into mechanically destructive energy, and successfully fragments various types of urinary and biliary calculi even including those calculi with poor surface absorptance, like pure white cystine. A solid state laser, Ho:YAG (2.1 micrometers wavelength and 150 microsecond(s) pulse width), has also been tested as an alternative to the flashlamp-excited dye laser. The underwater shock wave induced by this laser has been measured and has successfully fragmented calculi with poor absorptance in the visible region.

  14. Comparison of a pulsed dye laser and electrohydraulic lithotripsy on porcine gallbladder and common bile duct in vitro.

    PubMed

    Birkett, D H; Lamont, J S; O'Keane, J C; Babayan, R K

    1992-01-01

    With the advent of minimal access biliary procedures there is a need for a safe intracorporal lithotripsy technique that can be used through small flexible endoscopes. Currently, the two techniques available are electrohydraulic lithotripsy and laser induced shock wave lithotripsy. In this study we compare the effect of a 504 nm coumarin pulsed dye laser and electrohydraulic lithotripsy on in vitro porcine gallbladder and common bile duct. Electrohydraulic lithotripsy at the lowest energy the generator would deliver caused perforation of both tissues in only a few pulses when a 1.9-F probe was placed in direct contact with the tissue. Energy from a 504 nm coumarin pulsed dye laser delivered through a 320-microns fiber placed in light contact with the tissue caused an energy-dependent perforation after 50 pulses in from none to 44% of tissues. It was also found that there was a higher incidence of perforation in more vascular than non-vascular tissue. When the EHL probe and the laser fiber were held 1-2 mm from the tissue surface, discharge of each resulted in no perforation. On histological examination of the tissues, the perforations were found to be very small with laser lithotripsy and considerably larger with the electrohydraulic lithotripsy. It was felt that laser lithotripsy in the clinical situation was likely to be much safer than electrohydraulic lithotripsy. PMID:1349415

  15. Holmium laser lithotripsy for ureteral calculi: an outpatient procedure.

    PubMed

    Yip, K H; Lee, C W; Tam, P C

    1998-06-01

    A retrospective review was conducted to evaluate the efficacy of ureteroscopic lithotripsy using the holmium laser with a semirigid endoscope in a newly established day surgery center. In 1996, 69 consecutive patients (40 male and 29 female) with a mean age of 46.7 (range 21-73) years and ASA status I or II underwent ureteroscopic lithotripsy for their ureteral calculi using the holmium laser (365-micron fiber; power setting 0.5-1.4 J/5 Hz) and 8.5F semirigid ureteroscope in a day surgery setting. Stone features, postoperative pain scores, readmissions, and complications were evaluated. Eighteen upper, 17 middle, and 34 lower ureteral stones were treated, with a mean size measuring 12.1 (5-45) mm. The mean operative time was 61 minutes including the anesthetic time (range 15-150 minutes), and the success rate was 91% (63/69). The complication rate was 10% (7/69) including four unscheduled readmissions (6%). Telephone follow-up on postoperative Day 1 and Day 3 revealed mean pain scores of 2 and 1, respectively (on a 0-10 scale) and an analgesic requirement of 1 tablet of Dologesic (containing 32.5 mg of dextropropoxyphene + 320 mg of paracetamol) four times a day on both days. Ureteroscopic lithotripsy using the holmium laser and a semirigid endoscope is highly successful and well tolerated and carries a low complication rate. It is indicated as an ambulatory and minimally invasive treatment modality in low-risk patients with ureteral stones. PMID:9658294

  16. Holmium laser lithotripsy of bladder calculi

    NASA Astrophysics Data System (ADS)

    Beaghler, Marc A.; Poon, Michael W.

    1998-07-01

    Although the overall incidence of bladder calculi has been decreasing, it is still a significant disease affecting adults and children. Prior treatment options have included open cystolitholapaxy, blind lithotripsy, extracorporeal shock wave lithotripsy, and visual lithotripsy with ultrasonic or electrohydraulic probes. The holmium laser has been found to be extremely effective in the treatment of upper tract calculi. This technology has also been applied to the treatment of bladder calculi. We report our experience with the holmium laser in the treatment of bladder calculi. Twenty- five patients over a year and a half had their bladder calculi treated with the Holmium laser. This study was retrospective in nature. Patient demographics, stone burden, and intraoperative and post-operative complications were noted. The mean stone burden was 31 mm with a range of 10 to 60 mm. Preoperative diagnosis was made with either an ultrasound, plain film of the abdomen or intravenous pyelogram. Cystoscopy was then performed to confirm the presence and determine the size of the stone. The patients were then taken to the operating room and given a regional or general anesthetic. A rigid cystoscope was placed into the bladder and the bladder stone was then vaporized using the holmium laser. Remaining fragments were washed out. Adjunctive procedures were performed on 10 patients. These included transurethral resection of the prostate, transurethral incision of the prostate, optic internal urethrotomy, and incision of ureteroceles. No major complications occurred and all patients were rendered stone free. We conclude that the Holmium laser is an effective and safe modality for the treatment of bladder calculi. It was able to vaporize all bladder calculi and provides a single modality of treating other associated genitourinary pathology.

  17. Femtosecond laser lithotripsy: feasibility and ablation mechanism

    NASA Astrophysics Data System (ADS)

    Qiu, Jinze; Teichman, Joel M. H.; Wang, Tianyi; Neev, Joseph; Glickman, Randolph D.; Chan, Kin Foong; Milner, Thomas E.

    2010-03-01

    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 (λ=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 μm, 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 μm, 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.

  18. Laser lithotripsy with the Ho:YAG laser: fragmentation process revealed by time-resolved imaging

    NASA Astrophysics Data System (ADS)

    Schmidlin, Franz R.; Beghuin, Didier; Delacretaz, Guy P.; Venzi, Giordano; Jichlinski, Patrice; Rink, Klaus; Leisinger, Hans-Juerg; Graber, Peter

    1998-07-01

    Improvements of endoscopic techniques have renewed the interest of urologists in laser lithotripsy in recent years. Laser energy can be easily transmitted through flexible fibers thereby enabling different surgical procedures such as cutting, coagulating and lithotripsy. The Ho:YAG laser offers multiple medical applications in Urology, among them stone fragmentation. However, the present knowledge of its fragmentation mechanism is incomplete. The objective was therefore to analyze the fragmentation process and to discuss the clinical implications related to the underlying fragmentation mechanism. The stone fragmentation process during Ho:YAG laser lithotripsy was observed by time resolved flash video imaging. Possible acoustic transient occurrence was simultaneously monitored with a PVDF-needle hydrophone. Fragmentation was performed on artificial and cystine kidney stones in water. We observed that though the fragmentation process is accompanied with the formation of a cavitation bubble, cavitation has only a minimal effect on stone fragmentation. Fragment ejection is mainly due to direct laser stone heating leading to vaporization of organic stone constituents and interstitial water. The minimal effect of the cavitation bubble is confirmed by acoustic transients measurements, which reveal weak pressure transients. Stone fragmentation with the Holmium laser is the result of vaporization of interstitial (stone) water and organic stone constituents. It is not due to the acoustic effects of a cavitation bubble or plasma formation. The fragmentation process is strongly related with heat production thereby harboring the risk of undesired thermal damage. Therefore, a solid comprehension of the fragmentation process is needed when using the different clinically available laser types of lithotripsy.

  19. Laser lithotripsy using double pulse technique

    NASA Astrophysics Data System (ADS)

    Helfmann, Juergen; Doerschel, Klaus; Mueller, Gerhard J.

    1990-07-01

    There are currntly several methods in the field of laser lithotripsy which operate not only at different wavelengths and pulse lengths but also with various types of optical front ends and various irrigation fluids'6. The methods can be divided into two main groups: First, those which utilize stone absorption and plasma formation on the stone surface to initiate stone fragmentation, such as dye lasers. Second, those which generate shock waves and caviatation in the surrounding fluid and which require additional means to produce aplasma (e.g. irrigation, focussing fiber end or metal surfaces). The pulsed Nd:YAG laser belongs to this group. The method presented here is the double pulse technique which is a combination of both methods. It uses two laser pulses with a short time delay transmitted by means of a fiber to destroy body concrements. The first pulse is the first harmonic of the Nd:YAG laser (532nm) which improves the coupling efficiency of the laser radiation with the stone. The second pulse is in the fundamental mode of the laser (1064 nm) delivering the high energy for the stone disruption.

  20. Spectroscopic feedback in laser lithotripsy and laser angioplasty

    NASA Astrophysics Data System (ADS)

    Jiang, Zhi X.; King, Terence A.; Shah, T.; Watson, Graham M.

    1992-08-01

    The feasibility of new forms of monitoring the fragmentation and ablation process through the plasma feedback signals in laser lithotripsy and laser angioplasty has been investigated. In laser lithotripsy it has been found that shock wave feedback monitoring is not as reliable as the plasma emission feedback monitoring. The plasma emission spectra indicate clearly plasma formation on calculi or calcified plaque, while an audible signal can be observed on targets such as dark tissue, catheter, and blood. This technique was successful in ex-vivo experiments in which calculi were inserted into pigs' ureter and then fragmented. Spectra were obtained in vivo indicating calcium abundance in calculi and the feasibility of real-time stone composition analysis. Ex-vivo gallstone fragmentation was also performed successfully under plasma spectra feedback monitoring. In laser angioplasty, in vitro experiments have shown a discriminative effect at laser pulse energies of 40 mJ or greater. Strong plasma spectra can only be observed from calcified plaque and not from normal artery tissue or fibrous plaque. The threshold for plasma formation on calcified plaque increases in blood compared to that in saline while the spectral structure becomes more specific. This study shows promising prospects for the technique in both laser lithotripsy and laser angioplasty.

  1. Laser lithotripsy of difficult bile duct stones under direct visual control.

    PubMed Central

    Neuhaus, H; Hoffmann, W; Zillinger, C; Classen, M

    1993-01-01

    Biliary laser lithotripsy was performed under direct visual control in 35 consecutive patients not amenable to routine endoscopy. The patients had 1-50 (median 1) bile duct stones with the greatest diameter of the largest stone being 9-42 mm (median 20 mm). Conventional endoscopic treatment had failed because of an inaccessible papilla (16 patients), biliary strictures (seven patients), and impaction or large size of calculi (12 patients). Twelve patients, depending on their anatomical condition, underwent peroral cholangioscopy by means of a mother-babyscope system. Percutaneous cholangioscopy was initially carried out in 23 patients, 7-20 days (median 10 days) after creation of a transhepatic fistula. Pulsed dye laser (32 patients) or alexandrite laser (three patients) lithotripsy was applied under an appropriate direct visual control in all cases. Complete stone disintegration succeeded in 33 of 35 patients. All resultant fragments passed the papilla within a mean number of 1.3 treatment sessions. Peroral cholangioscopic lithotripsy failed in two cases. One patient successfully underwent percutaneous laser treatment and the other patient was referred to surgery. Fever, temporary haemobilia, or a subcapsular liver haematoma were seen in a total of eight patients during establishment of the cutaneobiliary fistula. A 95 year old patient who had been admitted with septic cholangitis died because of cardiorespiratory failure 5 days after bile duct clearance. It is concluded that laser lithotripsy performed under a direct visual control is an effective and safe procedure for the non-surgical treatment of difficult bile duct stones. Ductal clearance can usually be achieved in a single treatment session when the papilla and the stones are accessible by the peroral route. Percutaneous cholangioscopic lithotripsy is more time consuming but highly effective even in patients with a difficult anatomy, bile duct strictures, or intrahepatic calculi. This approach should be

  2. Fragmentation process induced by microsecond laser pulses during lithotripsy

    NASA Astrophysics Data System (ADS)

    Rink, K.; Delacrétaz, G.; Salathé, R. P.

    1992-07-01

    A fiber optic stress sensing technique is applied to evaluate the fragmentation mechanism for pulsed dye-laser lithotripsy. We demonstrate for the first time that the fragmentation process with microsecond laser pulses originates from the shock wave induced by the cavitation bubble collapse. This shock occurs some hundreds of microseconds after the laser pulse. The shock induced by the plasma expansion, which occurs during laser irradiation, has a minor effect.

  3. Endoscopic Gastrointestinal Laser Therapy

    PubMed Central

    Buchi, Kenneth N.

    1985-01-01

    The development of flexible fibers for the delivery of laser energy led to the first endoscopic laser applications in humans in the early 1970s. Since that time, much has been learned about applications throughout the gastrointestinal tract. The risks appear to be minimal. The coagulative effect of laser energy is used to treat gastrointestinal hemorrhage and small, benign mucosal lesions. The ablative effect of the Nd:YAG laser on tissue is used for palliative therapy for malignant gastrointestinal disorders and incisional therapy for anatomic lesions such as strictures or cysts. New laser modalities that potentially can be tuned throughout large segments of the electromagnetic spectrum, new fiber-optic delivery systems with specialized tips and new methods of sensitizing tissue to laser energy all indicate that the endoscopic laser should continue to have many new and innovative applications. ImagesFigure 1.Figure 2.Figure 3. PMID:3911589

  4. [The endoscopic treatment of large calculi in the choledochus. The preliminary results with intracorporeal electrohydraulic shock-wave lithotripsy].

    PubMed

    Vladimirov, B

    1990-01-01

    Results are reported of endoscopic treatment of: 236 patients with common bile duct calculi treated by endoscopic sphincterotomy with or without hydrostatic balloon extraction and extraction of the calculi, mechanical lithotripsy and endoprosthesis; preliminary results in 12 patients treated by intracorporeal electrohydraulic lithotripsy. Complete removal of calculi from the common bile duct was achieved in 171 of 236 sphincterotomized patients (72 per cent). Complications were observed in 11 per cent of the patients. Mechanical cracking of common bile duct calculi was realized in 60 of 65 patients (92 per cent) with complications observed in 3 per cent. Thus, with the use of mechanical lithotripsy the success of endoscopic treatment rose to 98 per cent, without increase in the incidence of complications. Seven patients had endoprostheses placed because of failure to extract the calculi. Intracorporeal electrohydraulic lithotripsy was performed in 12 patients with common bile duct lithiasis (4 with single and 8 with numerous stones with diameter 20-40 mm. In one patient transient acute pancreatitis was observed. A rise in serum amylase content was recorded in 9 patients. The stones in the common bile duct were effectively broken to pieces and removed in 8 patients. Lithotripsy was unsuccessful in 4 patients, two of whom had solid calcium depositions. In the common bile duct of the other two MTBE gas applied. The patients were subjected to repeated lithotripsy with positive effect. It is pointed out in conclusion that crushing stones in the common bile duct allows real improvement of the results of endoscopic sphincterotomy in common bile duct calculosis. Endoscopic treatment of larger calculi became also feasible which until a few years ago were contraindication for endoscopic treatment. PMID:2102523

  5. 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.

  6. Holmium:YAG laser lithotripsy for the management of urolithiasis in small ruminants and pot-bellied pigs

    NASA Astrophysics Data System (ADS)

    Halland, Spring K.; House, John K.; George, Lisle

    2001-05-01

    Obstructive urolithiasis is a common problem in small ruminants and pot-bellied pigs. The most common site of urinary tract obstruction in these species is the urethra. Surgical procedures developed to relieve obstructions, in our experience have been effective in approximately 75% of cases. Urethral stricture is a common complication if the mucosa of the urethra is disrupted. The objective of this project was to evaluate endoscopy guided laser lithotripsy as a therapeutic modality to relieve urethral obstructions in small ruminants and pot-bellied pigs. The study population consisted of patients presented to the Veterinary Medical Teaching Hospital at the University of California Davis with obstructive urolithiasis. Lithotripsy was performed using a Holmium:YAG laser via a 200-micron low water quartz fiber passed through a flexible mini-endoscope. Two types of urinary calculi were managed with this technique, calcium carbonate and calcium hydroxyphosphate. Laser lithotripsy was effective at relieving obstructions caused by both types of calculi when conventional methods had failed. Laser lithotripsy performed via urethral endoscopy is a safe and effective therapeutic modality for management of obstructive urolithiasis in small ruminants and pot-bellied pigs and reduces the risk of post procedural urethral stricture.

  7. Influence of Saline on Temperature Profile of Laser Lithotripsy Activation

    PubMed Central

    Silva, Igor N.; Donalisio da Silva, Rodrigo; Gustafson, Diedra; Sehrt, David; Kim, Fernando J.

    2015-01-01

    Abstract Purpose: We established an ex vivo model to evaluate the temperature profile of the ureter during laser lithotripsy, the influence of irrigation on temperature, and thermal spread during lithotripsy with the holmium:yttrium-aluminum-garnet (Ho:YAG) laser. Materials and Methods: Two ex vivo models of Ovis aries urinary tract and human calcium oxalate calculi were used. The Open Ureteral Model was opened longitudinally to measure the thermal profile of the urothelium. On the Clinical Model, anterograde ureteroscopy was performed in an intact urinary system. Temperatures were measured on the external portion of the ureter and the urothelium during lithotripsy and intentional perforation. The lithotripsy group (n=20) was divided into irrigated (n=10) and nonirrigated (n=10), which were compared for thermal spread length and values during laser activation. The intentional perforation group (n=10) was evaluated under saline flow. The Ho:YAG laser with a 365 μm laser fiber and power at 10W was used (1J/Pulse at 10 Hz). Infrared Fluke Ti55 Thermal Imager was used for evaluation. Maximum temperature values were recorded and compared. Results: On the Clinical Model, the external ureteral wall obtained a temperature of 37.4°C±2.5° and 49.5°C±2.3° (P=0.003) and in the Open Ureteral Model, 49.7°C and 112.4°C with and without irrigation, respectively (P<0.05). The thermal spread along the external ureter wall was not statically significant with or without irrigation (P=0.065). During intentional perforation, differences in temperatures were found between groups (opened with and without irrigation): 81.8°±8.8° and 145.0°±15.0°, respectively (P<0.005). Conclusion: There is an increase in the external ureteral temperature during laser activation, but ureteral thermal values decreased when saline flow was applied. Ureter thermal spread showed no difference between irrigated and nonirrigated subgroups. This is the first laser lithotripsy thermography study

  8. Intracorporeal lithotripsy with the holmium:YAG laser

    NASA Astrophysics Data System (ADS)

    Denstedt, John D.; Razvi, Hassan A.; Chun, Samuel S.; Sales, Jack L.

    1995-05-01

    A variety of devices are currently available for intracorporeal stone fragmentation. Recently a new wavelength of laser, the Holmium:YAG, has demonstrated a variety of potential urologic applications including ablation of soft tissue lesions as well as stone fragmentation. This laser has a wavelength of 2100 nm and operates in a pulsed mode. Energy is delivered through a 400 um quartz end-firing fiber. In this presentation we review our clinical experience with the Holmium:YAG laser for the treatment of renal and ureteral calculi. Over a 23 month period, 63 patients underwent 67 procedures. Seven procedures consisted of percutaneous nephrolithotripsy for large or staghorn renal calculi. Sixty procedures were performed for ureteral stones. Procedures for proximal ureteral stones (6) employed a retrograde approach using flexible ureteroscopes (8.5 or 9.8). Stones in the mid ureter (12) and distal ureter (42) were approached transurethrally using a 6.9 rigid ureteroscope. Complete stone fragmentation without the need for additional procedures was achieved in 82% of cases. Treatment failures included 1 stone migration into the renal pelvis during laser activation, 6 patients who had incomplete fragmentation and 3 patients in which laser malfunction precluded complete fragmentation. Stone analysis available in 23 patients revealed calcium oxalate monohydrate (15), calcium oxalate dihydrate (2), cystine (2), uric acid (3) and calcium phosphate (1). A single complication of ureteral perforation occurred when the laser was fired without direct visual guidance. Radiographic follow-up at an average of 16 weeks is available in 22 patients and has identified 2 patients with ureteral strictures that are not believed to be related to laser lithotripsy. In summary, we have found the Holmium:YAG laser to be a reliable and versatile device for intracorporeal lithotripsy. Its safety and efficacy make it a suitable alternative for performing intracorporeal lithotripsy of urinary

  9. Laser-induced shock-wave lithotripsy of canine urocystoliths and nephroliths

    NASA Astrophysics Data System (ADS)

    Woods, J. P.; Bartels, Kenneth E.; Stair, Ernest L.; Schafer, Steven A.; Nordquist, Robert E.

    1997-05-01

    Urolithiasis is a common disease affecting dogs which can sometimes be treated with dietary and medical protocols. In many cases, however, medical management cannot be employed because the dietary restrictions are contraindicated, effective medical dissolution protocols for the calculi (uroliths) do not exist, or obstruction by the calculi may result in deterioration of renal function during the time required for medical dissolution. At present, the management of medically untreatable calculi has been surgical removal which may result in temporary but dramatic decrease in renal function, irreversible loss of damaged nephrons, and significant risk, particularly for bilateral or recurrent nephroliths. An innovative technique for the removal of these uroliths would involve laser lithotripsy which transforms light energy into acoustical energy generating a shock wave sufficient to fragment stones (photoacoustic ablation). The laser is transmitted via quartz fibers which are small and flexible and can be used under direct vision through endoscopes resulting in effective fragmentation with little surrounding tissue damage. Lasers are becoming increasingly more utilized in veterinary medicine, in contrast to the limited availability of other non-invasive methods of treatment of nephroliths (i.e. extracorporeal shock-wave lithotripsy).

  10. 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.

  11. Sialoendoscopy with and without holmium:YAG laser-assisted lithotripsy in the management of obstructive sialadenitis of major salivary glands.

    PubMed

    Sionis, S; Caria, R A; Trucas, M; Brennan, P A; Puxeddu, R

    2014-01-01

    Obstructive sialadenitis is a major cause of dysfunction of the salivary glands, and increasingly sialoendoscopy is used in both diagnosis and treatment. At present the limit of the endoscopic approach is the size of the stone as only stones of less than 4mm can be removed. Endoscopic laser lithotripsy has the potential to treat many stones larger than this with minimal complications and preservation of a functional salivary gland. The holmium:YAG laser has been widely and safely used in urology, and its use has been recently proposed in salivary lithotripsy for the removal of bigger stones. We describe our experience with sialoendoscopy for stones in the parotid and submandibular glands and assess the feasibility and the efficacy of holmium:YAG laser lithotripsy. We have used the procedure 50 times for 43 patients with obstructive sialadenitis; 31 patients had sialolithiasis, 15 of whom (48%) had stones with diameters between 4 and 15mm (mean 7). Total extraction after fragmentation was possible in 14 of the 15 patients without complications. Intraductal holmium:YAG laser lithotripsy is effective and safe, and allows the treatment of large stones in Stensen's and Wharton's ducts. PMID:24280118

  12. Lithotripsy with the alexandrite laser: our initial 100 clinical cases.

    PubMed

    Pertusa, C; Albisu, A; Acha, M; Blasco, M; Llarena, R; Arregui, P

    1991-01-01

    The alexandrite laser system has proven to be an effective and safe method of treating ureteral stones. When the electromagnetic energy of a laser light pulse is selectively absorbed by the stone, a plasma forms at the surface. This plasma, which is composed of ions and electrons, continues to absorb laser energy, reaching very high pressure and generating a shock wave that fragments the stone. The degree of stone fragmentation is directly related to the composition and crystal lattice structure of the calculus. 112 calculi have been treated, and laser lithotripsy was successful in 87.5%. 6% of the stones were inadvertently flushed back into the kidney. No patient required an open ureterolithotomy. Guidance of the laser fiber onto the stone was performed by rigid ureteroscopy. There were no troublesome complications, and in a 3-month follow-up, no sequelae were reported. PMID:1687678

  13. 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.

  14. Thulium fiber laser lithotripsy in an in vitro ureter model.

    PubMed

    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. PMID:25518001

  15. Laser lithotripsy: a review of 20 years of research and clinical applications.

    PubMed

    Dretler, S P

    1988-01-01

    Four new technologies have transformed the treatment of urinary calculi: electrohydraulic lithotripsy, ultrasonic lithotripsy, extracorporeal shock wave lithotripsy, and laser lithotripsy. Initial attempts to ablate urinary calculi by continuous wave CO2, ruby, and Nd-YAG lasers failed because of excess thermal injury and inability to pass the laser energy via a flexible fiber. Basic laboratory studies then demonstrated that short pulsed laser energy absorbed by the calculus resulted in fragmentation. The parameters that produced optimal urinary calculus fragmentation were found using the flashlamp pumped tunable dye laser, with the following parameters: wavelength: 504 nm; pulse duration: 1 microsec; fiber: 250 micro silica-coated quartz; repetition: 5-20 Hz. Use of pulsed dye laser caused no tissue damage. The mechanism of fragmentation is light absorption, plasma development, and repetitive acoustic shock wave action with resultant fragmentation. The techniques for application of laser to calculi have been successful, and new, miniature instruments have been developed. Laser lithotripsy is a successful method for fragmenting ureteral calculi. The small caliber of the laser fiber makes this method useful for treating calculi in narrow, tortuous ureters; impacted calculi; distal calculi in ureters that cannot be dilated, via the percutaneous route for stones in calyces or impacted in the upper ureter. Investigations are continuing to optimize fragmentation of harder calculi and to use laser fragmentation within the kidney. Laser lithotripsy may also be used to fragment biliary calculi. PMID:2902498

  16. Visualizing mechanical stress and liquid flow during laser lithotripsy

    NASA Astrophysics Data System (ADS)

    Reinten, Ilja; Verdaasdonk, Rudolf; van der Veen, Albert; Klaessens, John

    2014-03-01

    The mechanism of action of the holmium laser lithotripsy is attributed to explosive expanding and imploding vapor bubbles in association with high-speed water jets creating high mechanical stress and cracking the stone surface. A good understanding of this mechanism will contribute to the improvement and the safety of clinical treatments. A new method has been developed to visualize the dynamics of mechanical effects and fluid flow induced by Holmium laser pulses around the fiber tip and the stone surface. The fiber tip was positioned near the surface of a stone on a slab of polyacrylamide gel submerged in water. The effects were captured with high speed imaging at 2000-10000 f/s. The dynamics of the pressure wave after the pulse could be visualized by observing the optical deformation of a fine line pattern in the background of the water container using digital subtraction software. This imaging technique provides a good understanding of the mechanical effects contributing to the effectiveness and safety of lithotripsy and can be used to study the optimal fiber shape and position towards the stone surface.

  17. Laser lithotripsy of a urethral calculus via ischial urethrotomy in a steer.

    PubMed

    Streeter, R N; Washburn, K E; Higbee, R G; Bartels, K E

    2001-09-01

    A steer examined because of obstructive urolithiasis and urethral rupture underwent laser lithotripsy, using a chromium-thulium-holmium:yttrium-aluminum-garnet (Ho:YAG) laser inserted through an ischial urethrotomy. Procedures were performed with caudal epidural anesthesia. Six months after surgery, the urethra was patent with no clinical evidence of urethral stricture or fistula. Ischial urethrotomy provided rapid access to the bladder for catheterization and to the obstructive urolith for lithotripsy. Laser lithotripsy was a rapid and effective means of urolith removal in this steer. PMID:11549094

  18. Laser lithotripsy for removal of uroliths in dogs

    NASA Astrophysics Data System (ADS)

    Adams, Larry G.; Lulich, Jody P.

    2006-02-01

    Introduction: This study evaluated the ability to fragment and remove naturally occurring uroliths in dogs using a holmium: YAG laser. Methods: Twenty four dogs with naturally occurring uroliths including 10 spayed females and 14 neutered males. The dogs were 8.7 +/- 2.8 years old and weighed 13.7 +/- 8.0 kg. All dogs had bladder stones and 5 male dogs also had urethral stones. In female dogs, cystoscopy was performed using a rigid cystoscope with sheath diameter of 14 to 19 french. Cystoscopy was performed in males dogs using a 7.5 french diameter pediatric ureteroscope. Uroliths were fragmented using a 20 watt Holmium: YAG laser and the fragments were removed by basket extraction and voiding urohydropropulsion. Results: Average laser parameters for urolith fragmentation were 0.7 Joules at 8 Hertz (range: 0.5 to 1.3 Joules at 5 to 13 Hertz). All urolith fragments were successfully removed in all 10 female dogs and 11 of 14 male dogs. In one male dog, the urethra was too small to allow passage of the ureteroscope. In one of the male dogs, the urethral stones were successfully removed by laser lithotripsy, but removal of the bladder stones was performed by cystotomy. There was one complication of urethral perforation during attempts to pass an access sheath transurethrally in a dog with extensive proliferative urethritis. Conclusions: Laser lithotripsy is a safe and effective method of removing bladder and urethral stones in dogs provided the dog is large enough to permit transurethral passage of a cystoscope or ureteroscope.

  19. Successful Removal of a Large Common Bile Duct Stone by Using Direct Peroral Cholangioscopy and Laser Lithotripsy in a Patient with Severe Kyphosis.

    PubMed

    Lee, Song I; Lim, Byung Hun; Heo, Won Gak; Kim, Young Jun; Kim, Tae Hyeon

    2016-07-01

    A 75-year-old woman with hypertension presented with acute suppurative cholangitis. Chest radiography revealed severe kyphosis. Abdominal computed tomography revealed a large stone impacted in the common bile duct (CBD). The patient underwent emergent endoscopic retrograde cholangiopancreatography, and cholangiography revealed a large stone (7×3 cm) in the CBD that could not be captured using a large basket. We could not use the percutaneous approach for stone fragmentation by using a cholangioscope because of severe degenerative kyphosis. Finally, we performed holmium laser lithotripsy under peroral cholangioscopy by using an ultraslim endoscope, and the large stone in the CBD was successfully fragmented and removed without complications. PMID:27000425

  20. Successful Removal of a Large Common Bile Duct Stone by Using Direct Peroral Cholangioscopy and Laser Lithotripsy in a Patient with Severe Kyphosis

    PubMed Central

    Lee, Song I; Lim, Byung Hun; Heo, Won Gak; Kim, Young Jun; Kim, Tae Hyeon

    2016-01-01

    A 75-year-old woman with hypertension presented with acute suppurative cholangitis. Chest radiography revealed severe kyphosis. Abdominal computed tomography revealed a large stone impacted in the common bile duct (CBD). The patient underwent emergent endoscopic retrograde cholangiopancreatography, and cholangiography revealed a large stone (7×3 cm) in the CBD that could not be captured using a large basket. We could not use the percutaneous approach for stone fragmentation by using a cholangioscope because of severe degenerative kyphosis. Finally, we performed holmium laser lithotripsy under peroral cholangioscopy by using an ultraslim endoscope, and the large stone in the CBD was successfully fragmented and removed without complications. PMID:27000425

  1. 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.

  2. Safety and efficacy of holmium:YAG laser lithotripsy in patients with bleeding diatheses

    NASA Astrophysics Data System (ADS)

    Watterson, James D.; Girvan, Andrew R.; Cook, Anthony J.; Beiko, Darren T.; Nott, Linda; Auge, Brian K.; Preminger, Glenn M.; Denstedt, John D.

    2003-06-01

    Purpose: To assess the safety and efficacy of ureteroscopy and holmium:YAG (yttrium-aluminum-garnet) laser lithotripsy in the treatment of upper urinary tract calculi in patients with known and uncorrected bleeding diatheses. Materials and Methods: A retrospective chart review from 2 tertiary stone centers was performed to identify patients with known bleeding diatheses who were treated with holmium:YAG laser lithotripsy for upper urinary tract calculi. Twenty-five patients with 29 upper urinary tract calculi were treated with ureteroscopic holmium laser lithotripsy. Bleeding diatheses identified were coumadin administration for various conditions (17), liver dysfunction (3), thrombocytopenia (4), and von Willebrand's disease (1). Mean international normalized ratio (INR), platelet count and bleeding time were 2.3, 50 x 109/L, and > 16 minutes, for patients receiving coumadin or with liver dysfunction, thrombocytopenia, or von Willebrand's disease, respectively. Results: Overall, the stone-free rate was 96% (27/28) and 29 of 30 procedures were completed successfully without significant complication. One patient who was treated concomitantly with electrohydraulic lithotripsy (EHL) had a significant retroperitoneal hemorrhage that required blood transfusion. Conclusions: Treatment of upper tract urinary calculi in patients with uncorrected bleeding diatheses can be safely performed using contemporary small caliber ureteroscopes and holmium laser as the sole modality of lithotripsy. Ureteroscopic holmium laser lithotripsy without preoperative correction of hemostatic parameters limits the risk of thromboembolic complications and costs associated with an extended hospital stay. Avoidance of the use of EHL is crucial in reducing bleeding complications in this cohort of patients.

  3. Experience with endoscopic holmium laser in the pediatric population

    NASA Astrophysics Data System (ADS)

    Merguerian, Paul A.; Reddy, Pramod P.; Barrieras, Diego; Bagli, Darius J.; McLorie, Gordon A.; Khoury, Antoine E.

    1999-06-01

    Introduction: Due to the unavailability of suitable endoscopic instruments, pediatric patients have not benefited fully from the technological advances in the endoscopic management of the upper urinary tract. This limitation may be overcome with the Holmuim:Yttrium-Aluminum-Garnet(Ho:YAG) laser delivered via small instruments. To date, there is no published report on the use of this modality in children. Purpose: We evaluated the indications, efficacy, and complications of endourological Ho:YAG laser surgery in the treatment of pediatric urolithiasis, posterior urethral valves, ureterocele and ureteropelvic junction obstruction. Methods: The patient population included 10 children with renal, ureteral and bladder calculi, 2 children with posterior urethral valves, 2 children with obstructing ureteroceles, 2 children with ureteropelvic junction obstruction and 1 child with a urethral stricture. Access to the lesions was either antegrade via a percutaneous nephrostomy tract or retrograde via the urethra. A solid state Ho:YAG laser with maximum output of 30 watts (New Star lasers, Auburn, CA) was utilized as the energy source. Results: A total of 10 patients underwent laser lithotripsy. The means age of the patients was 9 yrs (5-13 yrs). The average surface area of the calculi as 425.2 mm2 (92-1645 mm2). 8 of the patients required one procedure to render them stone free, one patient had a staghorn calculus filling every calyx of a solitary kidney requiring multiple treatments and one other patient with a staghorn calculus required 2 treatments. There were no complications related to the laser lithotripsy. Two newborn underwent successful ablation of po sterious urethral valves. Two infants underwent incision of obstructing ureteroceles with decompression of the ureterocele on postoperative ultrasound. Two children underwent endypyelotomy for ureteropelvic junction obstruction. One was successful an done required an open procedure to correct the obstruction. One child

  4. Pulse-stretched Alexandrite laser for improved optical fiber reliability for laser lithotripsy

    NASA Astrophysics Data System (ADS)

    Simons, David; Koschmann, Eric C.

    1992-06-01

    Clinical data shows that short pulse duration lasers used in laser induced shock wave lithotripsy severely damage optical fibers on both the proximal and distal ends which is unsuitable for clinical use. An Alexandrite laser system has been developed that uses dynamic pulse stretching of the Q-switched laser pulse and improved optical fiber coupling to eliminate the fiber damage. The method of pulse stretching presented controls the laser output pulse energy from 50 to 150 millijoules and temporal shape from 0.5 to 1.5 microseconds. This yields effective fragmentation of calculi without damage to the optical fiber.

  5. Endoscopic laser therapy in gastroenterology.

    PubMed Central

    Pritikin, J; Weinman, D; Harmatz, A; Young, H

    1992-01-01

    Endoscopic laser therapy has become an important and widely used tool in gastroenterology. It has become important for outpatient palliative therapy for ablating obstructing gastrointestinal neoplasms. This method has often circumvented the need for major palliative surgical resections. Caution must be applied to laser therapy for potentially curable malignant neoplasms because, with vaporization of the target tissue, no tissue specimen is available to assure that local or invasive residual carcinoma is excluded. Therefore, in good surgical candidates, surgical resection of potentially curable cancers is always recommended. In the future, however, the combination of refined endoscopic ultrasonography and laser fluorescence techniques may lead to earlier detection, more precise localization, and even curative ablation of gastrointestinal malignancy. Images PMID:1413743

  6. Comparison of fluoride and sapphire optical fibers for Er: YAG laser lithotripsy.

    PubMed

    Qiu, Jinze; Teichman, Joel; Wang, Tianyi; Elmaanaoui, Badr; Gamez, David; Milner, Thomas E

    2010-06-01

    The long-pulse (200-350 micros) Holmium: YAG (Ho: YAG) laser (lambda = 2.12 microm) is used extensively in urology for laser lithotripsy. The long-pulse Erbium: YAG (Er: YAG) laser (lambda = 2.94 microm) fragments urinary calculi up to 5 times more efficiently than the Ho: YAG laser, however, no optical fibers are available to transmit efficiently 2.94 microm laser light for laser lithotripsy. We report results of a study evaluating a fluoride glass fiber to transmit Er: YAG laser light for laser lithotripsy and compare to a sapphire fiber that provides good transmission of Er: YAG light at low irradiance. The fluoride fiber provides superior light transmission efficiency over the sapphire fiber at an Er: YAG wavelength (2.94 microm). The sapphire fiber provides a more durable and robust delivery waveguide than the fluoride fiber when ablating urinary calculi in contact mode. Results of our study suggest that further development to improve performance of fluoride fibers for laser lithotripsy is warranted. PMID:20414904

  7. 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

  8. 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.

  9. 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.

  10. EXTRACORPOREAL SHOCK WAVE LITHOTRIPSY AND ENDOSCOPIC URETERAL STENT PLACEMENT IN AN ASIAN SMALL-CLAWED OTTER (AONYX CINEREA) WITH NEPHROLITHIASIS.

    PubMed

    Wojick, Kimberlee B; Berent, Allyson C; Weisse, Chick W; Gamble, Kathryn C

    2015-06-01

    Urolithiasis is a significant disease concern in Asian small-clawed otters (Aonyx cinerea), with over 60% of captive animals affected. Bilateral ureteral stent placement, using endoscopic and fluoroscopic guidance, and extracorporeal shock wave lithotripsy (ESWL) were performed as salvage procedures in a 13-yr-old intact female Asian small-clawed otter following a 7-yr history of nephrolithiasis and progressive renal insufficiency. Following the procedure, radiographs revealed a slight shifting of urolith position, although a decrease in urolith mass was not observed. As a result of declining quality of life related to severe osteoarthritis, the otter was euthanized 5 wk after the procedure. While this treatment approach was unsuccessful in this case, the technique was clinically feasible, so ESWL and ureteral stent placement may remain a consideration for other individuals of this species presented earlier in the course of this disease. PMID:26056891

  11. Ureteropyeloscopy and homium: YAG laser lithotripsy for treatment of ureteral calculi (report of 356 cases)

    NASA Astrophysics Data System (ADS)

    Wu, Zhong; Din, Qiang; Jiang, Hao-wen; Zen, Jing-cun; Yu, Jiang; Zhang, Yuanfang

    2005-07-01

    Objective: To evaluate the efficacy and safety of holmium YAG laser lithotripsy for the treatment of ureteral calculi. Methods: A total of 356 patients underwent ureteropyeloscopic lithotripsy using holmium YAG laser with a semirigid uretesopyeloscope, 93 upper, 135 middle, and 128 lower ureteral stones were treated. Results: The overall successful fragmentation rate for all ureteral stones in a single session achieved 98% (349/356). The successful fragmentation rate stratified by stone location was 95% 88/93 in the upper ureter, 99% (134/135) in the mid ureter , and 99%(127/128) in the distal ureter. 12 cases with bilateral ureteral stones which caused acute renal failure and anuria were treated rapidly and effectively by the holmium YAG laser lithotripsy. No complications such as perforation and severe trauma were encountered during the operations. 2 weeks 17months (with an average of 6.8 month ) follow up postoperatively revealed that the overall stone-free rate was 98%(343/349) and no ureteral stenosis was found. Conclusions Holmium YAG laser lithotripsy is a highly effective, minimally invasive and safe therapy for ureteral calculi. It is indicated as a first choice of treatment for patients with ureteral calculi, especially for the ones with mid- lower levels of ureteral calculi.

  12. [Endoscopic management of biliary stones].

    PubMed

    Barinagarrementería, R

    1990-07-01

    Endoscopic sphincterotomy is one of the more effective therapeutic procedures for the management of some biliary tree abnormalities. In choledocolitiasis, a 90% succesfull rate has been obtained. Complications include bleeding, perforation, cholangitis, and pancreatitis. Mortality rates between 1.0 to 1.3% are informed. Contraindications are the same as for panendoscopy as well as the presence of stones greater than 2.5 cms. In giant stones, some other endoscopic approaches can be used, including mechanical lithotripsy, chemical treatment, electrohydraulic shockwaves, laser and biliary stent application. Endoscopic sphincterotomy is also indicated as an adjuvant therapy previous to extracorporeal lithotripsy. PMID:19256137

  13. Management of impacted proximal ureteral stone: Extracorporeal shock wave lithotripsy versus ureteroscopy with holmium: YAG laser lithotripsy

    PubMed Central

    Khalil, Mostafa

    2013-01-01

    Objective: Prospective evaluation of the efficacy and safety of the extracorporeal shock wave lithotripsy (SWL) and ureteroscopy with Holmium: YAG laser lithotripsy (URSL) as a primary treatment for impacted stone in the proximal ureter. Patients and Methods: A total of 82 patients with a single impacted stone in the proximal ureter were included in the study. Patients were allocated into two groups according to patient preference for either procedure. The first group included 37 patients who were treated by SWL and the second group included 45 patients treated by URSL. The preoperative data and treatment outcomes of both procedures were compared and analyzed. Results: There was no difference as regards to patient and stone characters between the two groups. There was significantly higher mean session number and re-treatment rate in the SWL group in comparison to URSL group (1.5 ± 0.8 vs. 1.02 ± 0.15 session, and 43.2% vs. 2.2%, respectively). At one month, the stone-free rate of the URSL group was statistically significantly higher than that of the SWL group (80% vs. 67.6%, respectively). The stone-free rate at three months was still higher in the URSL group, but without statistically significant difference (80.2% vs. 78.4%, respectively). There was no statistically significant difference in the rate of complications between the SWL and URSL (24.3% vs. 15.6%, respectively). Conclusion: Both procedures can be used effectively and safely as a primary treatment for impacted stone in the proximal ureter; however, the URSL has a significantly higher initial stone-free rate and lower re-treatment rate. PMID:23798864

  14. New tunable flashlamp-pumped solid state Ti:sapphire laser for laser lithotripsy

    NASA Astrophysics Data System (ADS)

    Jiang, Zhi X.; Giannetas, V.; Charlton, Andrew; King, Terence A.

    1993-05-01

    Laser pulses from a flashlamp pumped, solid state Ti:sapphire laser (Vuman, free running untuned wavelength 792 nm, 2 microseconds pulse width and up to 240 mJ pulse energy) have been successfully and efficiently coupled into thin optical fibers. The coupling efficiency can be up to 67% for 300 micron and 43% for 200 micron core diameter optical fibers. With these two optical fibers in vitro laser lithotripsy has been performed successfully on various human calculi including gall bladder, kidney, ureter and salivary duct stones. The bright white flash of the induced plasma emission, strong shock waves, fiber recoil and stone propulsion and the splattering of the stone chips have been observed during the calculi fragmentation.

  15. Pulsed dye laser lithotripsy for treatment of urolithiasis in two geldings.

    PubMed

    Howard, R D; Pleasant, R S; May, K A

    1998-05-15

    Transendoscopic pulsed dye laser lithotripsy was effective in the treatment of calcium carbonate urothlithiasis in 2 adult geldings. Perineal urethrotomy provided convenient access for standing transendoscopic lithotripsy and evacuation of a large cystic calculus in one gelding. In the second horse, an obstructive urethral calculus was fragmented and removed by a transurethroscopic approach. Pulsed dye laser lithotriptor is effective in fragmentation of the most common form (calcium carbonate) of uroliths in horses and may be performed in standing horses with reduced surgical invasiveness and trauma to the urinary tract, compared with conventional approaches. The principle disadvantages include cost of the procedure, which is comparable to laparocystotomy, and the time delay required to make arrangements for use of the pulsed dye laser lithotriptor. PMID:9604033

  16. Effectiveness and Safety of Ureteroscopic Holmium Laser Lithotripsy for Upper Urinary Tract Calculi in Elderly Patients.

    PubMed

    Yoshioka, Takashi; Otsuki, Hideo; Uehara, Shinya; Shimizu, Toshihiro; Murao, Wataru; Fujio, Koji; Fujio, Kei; Wada, Koichiro; Araki, Motoo; Nasu, Yasutomo

    2016-06-01

    Upper urinary tract calculi are common; however, there is no recommended treatment selection for elderly patients. Ureteroscopic holmium laser lithotripsy (URS lithotripsy) is minimally invasive, and it provides a high stone-free rate (SFR) treatment for upper urinary tract calculi. Here, we retrospectively evaluated the surgical outcomes of URS lithotripsy after dividing the 189 cases into 3 groups by patient age: the '<65 group' (<65 years old, n=108), the '65-74 group' (65-74 years old, n=42), and the ' 75 group' ( 75 years old, n=39). The patients' characteristics, stone status, and perioperative outcomes were assessed. The 65-74 group and the 75 group had a significantly higher prevalence of hypertension compared to the<65 group. Compared to the<65 group, the 65-74 group had a significantly higher prevalence of hyperlipidemia, and the 75 group had significantly higher the American Society of Anesthesiologists (ASA) scores. Despite these preoperative risk factors, SFR and postoperative pyelonephritis in the 65-74 group and the 75 group were similar to those of the<65 group. In conclusion, URS lithotripsy is the preferred treatment for upper urinary tract calculi, even for elderly patients who have multiple preoperative risk factors. PMID:27339204

  17. The pulsed dye laser versus the Q-switched Nd:YAG laser in laser-induced shock-wave lithotripsy.

    PubMed

    Thomas, S; Pensel, J; Engelhardt, R; Meyer, W; Hofstetter, A G

    1988-01-01

    To date, there are two fairly well-established alternatives for laser-induced shock-wave lithotripsy in clinical practice. The Q-switched Nd:YAG laser is distinguished by the high-stone selectivity of its coupler systems. The necessity of a coupler system and its fairly small conversion rate of light energy into mechanical energy present serious drawbacks. Furthermore, the minimal outer diameter of the transmission system is 1.8 mm. The pulsed-dye laser can be used with a highly flexible and uncomplicated 200-micron fiber. However, the laser system itself is more complicated than the Q-switched Nd:YAG laser and requires a great deal of maintenance. Biological evaluation of damage caused by direct irradiation shows that both laser systems produce minor damage of different degrees. YAG laser lithotripsy with the optomechanical coupler was assessed in 31 patients with ureteral calculi. The instability and limited effectiveness of the fiber application system necessitated auxiliary lithotripsy methods in 14 cases. Dye-laser lithotripsy is currently being tested in clinical application. Further development, such as systems for blind application or electronic feedback mechanisms to limit adverse tissue effects, have yet to be optimized. Nevertheless, laser-induced shock-wave lithotripsy has the potential to become a standard procedure in the endourologic management of stone disease. PMID:2902500

  18. Retrograde flexible ureterorenoscopic holmium-YAG laser lithotripsy: the new gold standard.

    PubMed

    Gould, D L

    1998-03-01

    To demonstrate the efficacy of flexible retrograde ureterorenoscopic holmium-YAG intracorporeal laser lithotripsy for the treatment of renal calculi, a total of 86 patients presenting to our hospital with renal calculi underwent flexible retrograde ureterorenoscopic holmium-YAG intracorporeal laser lithotripsy of their stones, and the data were collected prospectively. As extracorporeal shock wave lithotripsy is not available at our institution, all patients with renal calculi in this study were treated in a retrograde fashion using the Richard Wolf 6.0F semirigid ureteroscope, the 7.5F flexible ureterorenoscope, and the holmium-YAG laser by Coherent Inc. Except for inhospital consults or patients requiring admission secondary to infection, all cases were performed on an ambulatory basis. All renal calculi 3 cm or smaller were approached in a retrograde fashion. Where possible, the stones were initially debulked using the semirigid ureteroscope and the 550-microm fiber followed by the flexible ureterorenoscope in combination with the 360- or 200-microm laser fiber depending on stone position. Stones were fragmented until they were small enough to be removed by hydrocleansing. Using this technique, stone-free success rates for calculi 2.5 cm or smaller after a single treatment, regardless of stone composition or location, are superior to those of extracorporeal shock wave lithotripsy. For calculi between 2.5 and 3 cm, the results also are noted to be superior. We conclude that for calculi larger than 3 cm or for partial staghorn calculi, the treatment of choice appears to be a percutaneous approach. PMID:9568772

  19. Laser-assisted percutaneous endoscopic neurolysis.

    PubMed

    Epstein, J M; Adler, R

    2000-01-01

    Endoscopic lysis of adhesive scar utilizing a steerable fiberoptic scope is currently being performed by a growing number of physicians. Various techniques and medications are presently being used to lyse epidural adhesions as a way of improving refractory lumbar radiculopathies. We present a case report discussing laser-assisted endoscopic lysis with radiographic images before and after laser-assisted neurolysis. We were able to demonstrate improvement in the filling of the nerve root with epidural contrast after the laser lysis of scar. This correlated with improvement in pain without neurologic deficit. The laser may represent a useful adjunct in the treatment of pain due to epidural fibrosis. PMID:16906206

  20. Comparison of holmium:YAG and thulium fiber lasers for lithotripsy

    NASA Astrophysics Data System (ADS)

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

    2010-02-01

    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 (μa = 160 cm-1 at λ = 1908 nm) is significantly greater than for the Holmium wavelength (μa = 28 cm-1 at λ = 2120 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 μs pulse duration was delivered through a 100-μm-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 ms pulse duration was also delivered through a 100-μm fiber for the same sets of 10 stones. For same number of pulses and total energy (126 J) delivered to each stone, mass loss averaged 2.4 +/- 0.6 mg (UA) and 0.7 +/- 0.2 mg (COM) for Holmium laser and 12.6 +/- 2.5 mg (UA) and 6.8 +/- 1.7 (COM) for Thulium fiber laser. UA and COM stone vaporization rates for Thulium fiber laser averaged 5-10 times higher than for 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.

  1. 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.

  2. 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. PMID:7725212

  3. Study of cavitation bubble dynamics during Ho:YAG laser lithotripsy by high-speed camera

    NASA Astrophysics Data System (ADS)

    Zhang, Jian J.; Xuan, Jason R.; Yu, Honggang; Devincentis, Dennis

    2016-02-01

    Although laser lithotripsy is now the preferred treatment option for urolithiasis, the mechanism of laser pulse induced calculus damage is still not fully understood. This is because the process of laser pulse induced calculus damage involves quite a few physical and chemical processes and their time-scales are very short (down to sub micro second level). For laser lithotripsy, the laser pulse induced impact by energy flow can be summarized as: Photon energy in the laser pulse --> photon absorption generated heat in the water liquid and vapor (super heat water or plasma effect) --> shock wave (Bow shock, acoustic wave) --> cavitation bubble dynamics (oscillation, and center of bubble movement , super heat water at collapse, sonoluminscence) --> calculus damage and motion (calculus heat up, spallation/melt of stone, breaking of mechanical/chemical bond, debris ejection, and retropulsion of remaining calculus body). Cavitation bubble dynamics is the center piece of the physical processes that links the whole energy flow chain from laser pulse to calculus damage. In this study, cavitation bubble dynamics was investigated by a high-speed camera and a needle hydrophone. A commercialized, pulsed Ho:YAG laser at 2.1 mu;m, StoneLightTM 30, with pulse energy from 0.5J up to 3.0 J, and pulse width from 150 mu;s up to 800 μs, was used as laser pulse source. The fiber used in the investigation is SureFlexTM fiber, Model S-LLF365, a 365 um core diameter fiber. A high-speed camera with frame rate up to 1 million fps was used in this study. The results revealed the cavitation bubble dynamics (oscillation and center of bubble movement) by laser pulse at different energy level and pulse width. More detailed investigation on bubble dynamics by different type of laser, the relationship between cavitation bubble dynamics and calculus damage (fragmentation/dusting) will be conducted as a future study.

  4. Treatment of Kidney Stone in a Kidney-Transplanted Patient with Mini-Percutaneous Laser Lithotripsy: A Case Report

    PubMed Central

    Markić, Dean; Krpina, Kristian; Ahel, Juraj; Gršković, Antun; Španjol, Josip; Rubinić, Nino; Materljan, Mauro; Mikolašević, Ivana; Orlić, Lidija; Rački, Sanjin

    2016-01-01

    We report a case of a kidney-transplanted patient with urolithiasis treated with mini-percutaneous laser lithotripsy. The patient presented with renal dysfunction and graft hydronephrosis. Diagnostic procedures revealed ureterolithiasis as a cause of obstruction, and percutaneous nephrostomy was inserted as a temporary solution. Before surgery, the stone migrated to the renal pelvis. Mini-percutaneous laser lithotripsy was successfully performed, and during surgery, all stone fragments were removed. Six months after successful treatment, the patient has good functioning and stone-free graft. PMID:27066492

  5. Gallbladder stone inspection and identification for laser lithotripsy

    NASA Astrophysics Data System (ADS)

    Makdisi, Yacob; Kokaj, Jahja O.

    1999-03-01

    Using high speed imaging techniques, the gall bladder stone immersed in liquid is detected and identified. The detection of the shock waves induced by laser power is reached by using interferometry technique. Using gall bladder and tissue images obtained by ultra-fast photography and time resolved laser fluorescence the correlation of correlation is performed. The tissue image is used to perform the correlation filter. Hence lower correlation output is used for firing of the laser power.

  6. Endoscopic management of difficult common bile duct stones

    PubMed Central

    Trikudanathan, Guru; Navaneethan, Udayakumar; Parsi, Mansour A

    2013-01-01

    Endoscopy is widely accepted as the first treatment option in the management of bile duct stones. In this review we focus on the alternative endoscopic modalities for the management of difficult common bile duct stones. Most biliary stones can be removed with an extraction balloon, extraction basket or mechanical lithotripsy after endoscopic sphincterotomy. Endoscopic papillary balloon dilation with or without endoscopic sphincterotomy or mechanical lithotripsy has been shown to be effective for management of difficult to remove bile duct stones in selected patients. Ductal clearance can be safely achieved with peroral cholangioscopy guided laser or electrohydraulic lithotripsy in most cases where other endoscopic treatment modalities have failed. Biliary stenting may be an alternative treatment option for frail and elderly patients or those with serious co morbidities. PMID:23345939

  7. Microscopic analysis of laser-induced proximal fiber tip damage during holmium:YAG and thulium fiber laser lithotripsy

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

    The thulium fiber laser (TFL) is being studied as an alternative to the standard holmium:YAG laser for lithotripsy. The 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 (e.g., 50- to 150-μm core) fibers than possible during holmium laser lithotripsy. This study examines whether the more uniform TFL beam profile also reduces proximal fiber tip damage compared with the holmium laser multimodal beam. Light and confocal microscopy images were taken of the proximal surface of each fiber to inspect for possible laser-induced damage. A TFL beam at a wavelength of 1908 nm was coupled into 105-μm-core silica fibers, with 35-mJ energy, and 500-μs pulse duration, and 100,000 pulses were delivered at each pulse rate setting of 50, 100, 200, 300, and 400 Hz. For comparison, single use, 270-μm-core fibers were collected after clinical holmium laser lithotripsy procedures performed with 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 pulse energy and average power were stable, and no proximal fiber damage was observed at settings up to 35 mJ, 400 Hz, and 14 W average power (n=5). In contrast, confocal microscopy images of fiber tips after holmium lithotripsy showed proximal fiber tip degradation, indicated by small ablation craters on the scale of several micrometers in all fibers (n=20). In summary, the proximal fiber tip of a 105-μm-core fiber transmitted up to 14 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 translate into lower costs for the surgical disposables as well.

  8. Ureteroscopy and holmium:YAG laser lithotripsy: an emerging definitive management strategy for symptomatic ureteral calculi in pregnancy

    NASA Astrophysics Data System (ADS)

    Watterson, James D.; Girvan, Andrew R.; Beiko, Darren T.; Nott, Linda; Wollin, Timothy A.; Razvi, Hassan A.; Denstedt, John D.

    2003-06-01

    Objectives: Symptomatic urolithiasis in pregnancy that does not respond to conservative measures has traditionally been managed with ureteral stent insertion or percutaneous nephrostomy (PCN). Holmium:yttrium-aluminum-garnet (YAG) laser lithotripsy using state-of-the-art ureteroscopes represents an emerging strategy for definitive stone management in pregnancy. The purpose of this study was to review the results of holmium laser lithotripsy in a cohort of patients who presented with symptomatic urolithiasis in pregnancy. Methods: A retrospective analysis was conducted at 2 tertiary stone centers from January 1996 to August 2001 to identify pregnant patients who were treated with ureteroscopic holmium laser lithotripsy for symptomatic urolithiasis or encrusted stents. Eight patients with a total of 10 symptomatic ureteral calculi and 2 encrusted ureteral stents were treated. Mean gestational age at presentation was 22 weeks. Mean stone size was 8.1 mm. Stones were located in the proximal ureter/ureteropelvic junction (UPJ) (3), mid ureter (1), and distal ureter (6). Results: Complete stone fragmentation and/or removal of encrusted ureteral stents were achieved in all patients using the holmium:YAG laser. The overall procedural success rate was 91%. The overall stone-free rate was 89%. No obstetrical or urological complications were encountered. Conclusions: Ureteroscopy and holmium laser lithotripsy can be performed safely in all stages of pregnancy providing definitive management of symptomatic ureteral calculi. The procedure can be done with minimal or no fluoroscopy and avoids the undesirable features of stents or nephrostomy tubes.

  9. Detachable fiber optic tips for use in thulium fiber laser lithotripsy

    NASA Astrophysics Data System (ADS)

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

    2013-03-01

    The thulium fiber laser (TFL) has recently been proposed as an alternative to the Holmium:YAG (Ho:YAG) laser for lithotripsy. The TFL's Gaussian spatial beam profile provides higher power transmission through smaller optical fibers with reduced proximal fiber tip damage, and improved saline irrigation and flexibility through the ureteroscope. However, distal fiber tip damage may still occur during stone fragmentation, resulting in disposal of the entire fiber after the procedure. A novel design for a short, detachable, distal fiber tip that can fit into an ureteroscope's working channel is proposed. A prototype, twist-lock, spring-loaded mechanism was constructed using micromachining methods, mating a 150-μm-core trunk fiber to 300-μm-core fiber tip. Optical transmission measuring 80% was observed using a 30-mJ pulse energy and 500-μs pulse duration. Ex vivo human calcium oxalate monohydrate urinary stones were vaporized at an average rate of 187 μg/s using 20-Hz modulated, 50% duty cycle 5 pulse packets. The highest stone ablation rates corresponded to the highest fiber tip degradation, thus providing motivation for use of detachable and disposable distal fiber tips during lithotripsy. The 1-mm outer-diameter prototype also functioned comparable to previously tested tapered fiber tips.

  10. Percutaneous yttrium aluminum garnet-laser lithotripsy of intrahepatic stones and casts after liver transplantation.

    PubMed

    Schlesinger, Nis Hallundbaek; Svenningsen, Peter; Frevert, Susanne; Wettergren, André; Hillingsø, Jens

    2015-06-01

    Bile duct stones and casts (BDSs) contribute importantly to morbidity after liver transplantation (LT). The purpose of this study was to estimate the clinical efficacy, safety, and long-term results of percutaneous transhepatic cholangioscopic lithotripsy (PTCSL) in transplant recipients and to discuss underlying factors affecting the outcome. A retrospective chart review revealed 18 recipients with BDSs treated by PTCSL laser lithotripsy with a holmium-yttrium aluminum garnet laser probe at 365 to 550 µm. They were analyzed in a median follow-up time of 55 months. In all but 1 patient (17/18 or 94%), it was technically feasible to clear all BDSs with a mean of 1.3 sessions. PTCSL was unsuccessful in 1 patient because of multiple stones impacting the bile ducts bilaterally; 17% had early complications (Clavien II). All biliary casts were successfully cleared; 39% had total remission; 61% needed additional interventions in the form of percutaneous transhepatic cholangiography and dilation (17%), re-PTCSL (11%), self-expandable metallic stents (22%), or hepaticojejunostomy (6%); and 22% eventually underwent retransplantation. The overall liver graft survival rate was 78%. Two patients died during follow-up for reasons not related to their BDS. Nonanastomotic strictures (NASs) were significantly associated with treatment failure. We conclude that PTCSL in LT patients is safe and feasible. NASs significantly increased the risk of relapse. Repeated minimally invasive treatments, however, prevented graft failure in 78% of the cases. PMID:25821134

  11. Application systems for the intracorporal laser-induced shockwave lithotripsy using the Nd:YAG Q-switched laser

    NASA Astrophysics Data System (ADS)

    Frank, Klaus H.; Eichenlaub, M.; Hessel, Stefan F. F.; Wondrazek, Fritz

    1990-06-01

    For the laser-induced shockwave lithotripsy the electromagnetic energy of a laser light pulse is converted intracorporally into the acoustic energy of a shock wave. The lithotriptor is based on a specially developed, Q-switched Nd:YAG laser whose high power light pulses (70 mJ, 25 ns) are coupled into a flexible quartz fiber of 600 pim core diameter. Using focussing elements energy densities higher than 6 1O J m2 can be achieved resulting in an optical breakdown in water followed by a shock wave. As a result of different absorption mechanisms the breakdown threshold can be decreased by placing a metallic target into the laser beam. The different shockwave formations of such optomechanical transducers have been measured. First clinical applications have been performed.

  12. Characterization of a 50-μm-core optical fiber for potential use in Thulium fiber laser lithotripsy

    NASA Astrophysics Data System (ADS)

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

    2014-03-01

    Our laboratory is currently studying the Thulium fiber laser (TFL) as a potential alternative laser lithotripter to the standard clinical Holmium:YAG laser. We have previously demonstrated efficient coupling of TFL energy into fibers as small as 100-μm-core-diameter without damage to the proximal end. Although smaller fibers have greater tendency to degrade at the distal tip during lithotripsy, fiber diameters (<= 200 μm) have been shown to increase saline irrigation rates through the working channel of a flexible ureteroscope, maximize ureteroscope deflection, and reduce stone retropulsion during laser lithotripsy. In this study, a 50-μm-core-diameter, 85-μm-outer-diameter fiber is characterized for TFL ablation of human calcium oxalate monohydrate urinary stones, ex vivo. The stone ablation rate was measured to be 70 +/- 22 μg/s for 35-mJ-pulse-energy, 500-μs-pulse-duration, and 50-Hz-pulse-rate. 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. Stone retropulsion and fiber burn-back averaged 201 +/- 336 and 3000 +/- 2600 μm, respectively, after 2 minutes. 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 alternatiμe to conventional Holmium:YAG laser lithotripsy using larger fibers.

  13. In vitro investigations of repulsion during laser lithotripsy using a pendulum set-up.

    PubMed

    Sroka, Ronald; Haseke, Nicolas; Pongratz, Thomas; Hecht, Volkmar; Tilki, Derya; Stief, Christian G; Bader, Markus Jürgen

    2012-05-01

    Ureteroscopic laser lithotripsy is a commonly used technique to treat ureteral calculi.The type of energy source used is one of the main influences of retrograd calculi propulsion. Using a momentum pendulum under-water set-up the induced momentum and the initial velocity were investigated. Pulsed laser light from three different clinically available laser systems, including a Ho:YAG laser, a frequency-doubled double-pulse (second harmonic generation, SHG) Nd:YAG laser and a flash-lamp pumped dye (FLPD) laser, were transmitted via flexible fibres of different core diameter to the front of the pendulum sinker. Single pulses at variable pulse energy, according to the clinical laser parameter settings, were applied to the target sinker, thus causing a repulsion-induced deflection which was documented by video recording. The maximum deflection was determined. Solving the differential equation of a pendulum gives the initial velocity, the laser-induced momentum and the efficiency of momentum transfer. The induced deflection as well as the starting velocity of the two short-duration pulsed laser systems (SHG Nd:YAG, FLPD) were similar (s (max) = 2-3.6 cm and v (0) = 150-200 mm/s, respectively), whereas both values were lower using the Ho:YAG laser with a long pulse duration (s (max) = 0.9--1.6 cm and v (0) = 60-105 mm/s, respectively). The momentum I induced by the Ho:YAG laser was only 50% and its transfer efficacy η (Repuls) was reduced to less than 5% of the values of the two short-pulsed laser systems. This investigation clearly showed the variable parts and amounts of repulsion using different pulsed lasers in an objective and reproducible manner. The momentum transfer efficiency could be determined without any physical friction problems. Further investigations are needed to compare stone fragmentation techniques with respect to laser repulsion and its clinical impact. PMID:22011742

  14. Integrated Multipoint-Laser Endoscopic Airway Measurements by Transoral Approach

    PubMed Central

    Neitsch, Marie; Horn, Iris-Susanne; Hofer, Mathias; Dietz, Andreas; Fischer, Miloš

    2016-01-01

    Objectives. Optical and technical characteristics usually do not allow objective endoscopic distance measurements. So far no standardized method for endoscopic distance measurement is available. The aim of this study was to evaluate the feasibility and accuracy of transoral airway measurements with a multipoint-laser endoscope. Methods. The semirigid endoscope includes a multipoint laser measurement system that projects 49 laser points (wavelength 639 nm, power < 5 mW) into the optical axis of the endoscopic view. Distances, areas, and depths can be measured in real-time. Transoral endoscopic airway measurements were performed on nine human cadavers, which were correlated with CT measurements. Results. The preliminary experiment showed an optimum distance between the endoscope tip and the object of 5 to 6 cm. There was a mean measurement error of 3.26% ± 2.53%. A Spearman correlation coefficient of 0.95 (p = 0.01) was calculated for the laryngeal measurements and of 0.93 (p < 0.01) for the tracheal measurements compared to the CT. Using the Bland-Altman-Plot, the 95% limits of agreement for the laryngeal measurements were satisfactory: −0.76 and 0.93. Conclusions. Integrated multipoint-laser endoscopic measurement is a promising technical supplement, with potential use in diagnostic endoscopy and transoral endoscopic surgery in daily practice. PMID:27022612

  15. 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

  16. Large subcapsular hematoma following ureteroscopic laser lithotripsy of renal calculi in a spina bifida patient: lessons we learn

    PubMed Central

    Vaidyanathan, Subramanian; Samsudin, Azi; Singh, Gurpreet; Hughes, Peter L; Soni, Bakul M; Selmi, Fahed

    2016-01-01

    Introduction Paraplegic patients are at greater risk of developing complications following ureteroscopic lithotripsy because of urine infection associated with neuropathic bladder, difficulties in access due to altered anatomy of urinary bladder and urethra, spinal curvature, spasticity, and contractures. We report the occurrence of large subcapsular hematoma following ureteroscopy and discuss lessons we learn from this case. Case report A 48-year-old male patient with spina bifida underwent ureteroscopy with laser lithotripsy and ureteric stenting for left ureteric stone and staghorn calculus with hydronephrosis; laser lithotripsy was repeated after 3 months; both procedures were performed by a senior urologist and did not result in any complications. Ureteroscopic laser lithotripsy was performed 5 months later by a urological trainee; it was difficult to negotiate the scope as vision became poor because of bleeding (as a result of the procedure). Postoperatively, hematuria persisted; temperature was 39°C. Cefuroxime was given intravenously followed by gentamicin for 5 days; hematuria subsided gradually; he was discharged home. Ten days later, this patient developed temperature, the urine culture grew Pseudomonas aeruginosa, and ciprofloxacin was given orally. Computed tomography (CT) of the urinary tract, performed 4 weeks after ureteroscopy, revealed a 9×7 cm subcapsular collection on the left kidney compressing underlying parenchyma. Percutaneous drainage was not feasible because of severe curvature of spine. Isotope renogram revealed deterioration in left renal function from 30% to 17%. Follow-up CT revealed reduction in the size of subcapsular hematoma, no hydronephrosis, and several residual calculi. Conclusion Risk of subcapsular hematoma following ureteroscopic lithotripsy can be reduced by avoiding prolonged endoscopy and performing ureteroscopy under low pressure. When a paraplegic patient develops features of infection after ureteroscopy, renal

  17. 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.

  18. Endoscopic laser palliation for advanced malignant dysphagia.

    PubMed Central

    Bown, S G; Hawes, R; Matthewson, K; Swain, C P; Barr, H; Boulos, P B; Clark, C G

    1987-01-01

    Palliative treatment of malignant dysphagia aims to optimise swallowing for the maximum time possible with the minimum of general distress to these seriously ill patients. Thirty four patients considered unsuitable for surgery because of advanced malignancy, other major pathology or in whom previous surgery had been unsuccessful were treated endoscopically with the Nd YAG laser. Significant improvement was achieved in 29 (85%). On a scale of 0-4 (0 = normal swallowing; 4 = dysphagia for all fluids), mean improvement was 1.7, with 25 patients (74%) able to swallow most, or all solids after treatment. With increasing experience, the average number of treatment sessions required for each patient became less; initial time in hospital became comparable to that needed for intubation. Failures were caused by inappropriate patient selection (3), or laser related perforation (2). The mean survival in the whole group was 19 weeks (range 2-44). Eighteen patients needed further treatment for recurrent dysphagia, a mean of six weeks (range 2-15) after initial therapy. Ten of these responded, but eight eventually required insertion of a prosthetic tube. The duration of good palliation was very variable after initial laser therapy. Images Fig. 3 PMID:2443431

  19. The use of laser lithotripsy status post cholecystostomy tube placement without interval cholecystectomy for calculous cholecystitis in a patient unfit for general anesthesia.

    PubMed

    Polite, Nathan M; Brown, Roy; Braveman, Joshua

    2013-12-01

    Acute cholecystitis in patients unfit for general anesthesia often initially requires cholecystectomy tube placement without cholecystectomy. The best way to definitively manage those patients with irreversible medical conditions, leaving them unable to undergo cholecystectomy, has yet to be defined. Laser lithotripsy is currently used in the management of stones of the genitourinary system. Extracorporeal shock wave cholelithotripsy has been extensively evaluated in Munich, Germany and since then, has been abandoned as an alternative treatment of cholelithiasis. This report discusses a novel approach using established cholecystocutaneous fistula tracts and laser lithotripsy to definitively treat this group of patients. PMID:24300938

  20. Flexible endoscope deflectability: changes using a variety of working instruments and laser fibers.

    PubMed

    Poon, M; Beaghler, M; Baldwin, D

    1997-08-01

    To measure the effects of different working instruments and holmium laser fibers on the deflectability in a variety of actively deflectable flexible endoscopes, a benchtop study was performed. The endoscopes studied were the Storz 7.5 flexible ureteroscope, the AUR-7 and AUR-9 flexible ureteroscopes (Circon-ACMI), a prototype Mitsubishi flexible ureteroscope (Mitsubishi Optics, Inc.), the ACN flexible cystoscope (Circon-ACMI), and the Storz flexible cystoscope. Working instruments included 1.6F (Wolf) and 1.9F (Microvasive) electrohydraulic lithotripsy (EHL) probes, 1.9F two-prong graspers and Bagley baskets, 2.4F Segura and helical baskets (Microvasive), 3.0F Segura basket, and 200- and 365-micron holmium laser fibers (Xintec). In ureteroscopes, the effect of 1.6F and 1.9F EHL probes ranged from having no effect in the Xintec 6,000, to decreasing deflection by 30 degrees in the AUR-7. Working instruments that were 2.4F or greater reduced deflection from 33 degrees to 93 degrees. Better deflectability was noted with the 200-micron holmium laser fiber than with the 365-micron fiber. The diameter of the working instrument did not affect deflectability as severely in cystoscopes. No significant differences in deflection existed between the 365-micron and 200-micron fibers in the flexible nephroscopes tested. In general, working instruments less than 2.4F and the 200-micron laser fiber have little effect on deflectability compared with working instruments 2.4F or larger and the 365-micron fiber. Flexible cystoscopes, with their larger working channels and stronger deflection cables, are affected less by working instrument diameter than are flexible ureteroscopes. PMID:9376842

  1. 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.

  2. Endoscopic Nd-YAG Laser Therapy for Gastric Polyp

    PubMed Central

    Cheong, Sun Moon; Sun, Duk Jhae; Rim, Kyu Sung

    1986-01-01

    With the development of a special quartz fiberoptic transmission system, the application of laser energy through an endoscope became possible. Now, endoscopic laser therapy is widely used for gastrointestinal bleeding, and gastrointestinal neoplasm, and we have removed broad-based gastric polyps using an endoscopic Nd:YAG laser in 12 patients between January and December 1985. The size of the polyps ranged from 0.2 cm to 1.0 cm in diameter. The most frequent location for the polyp was in the antrum (7 cases) and followed by the fundus (5 cases). The application number of laser energy was from 6 to 58 and the small lesions of the 10 patients were completely ablated by the first endoscopic laser therapy. Follow-up endoscopy in all patients revealed no new polyp formation, but all patients had a residual ulcer at the end of the first week post polypectomy, and ulcers were healed by the fifth week of follow up. PMID:3154618

  3. Endoscopic laser scalpel for head and neck cancer surgery

    NASA Astrophysics Data System (ADS)

    Patel, Snehal; Rajadhyaksha, Milind; Kirov, Stefan; Li, Yongbiao; Toledo-Crow, Ricardo

    2012-02-01

    Minimally invasive surgical (MIS) techniques, such as laparoscopic surgery and endoscopy, provide reliable disease control with reduced impact on the function of the diseased organ. Surgical lasers can ablate, cut and excise tissue while sealing small blood vessels minimizing bleeding and risk of lymphatic metastases from tumors. Lasers with wavelengths in the IR are readily absorbed by water causing minimal thermal damage to adjacent tissue, ideal for surgery near critical anatomical structures. MIS techniques have largely been unable to adopt the use of lasers partly due to the difficulty in bringing the laser into the endoscopic cavity. Hollow waveguide fibers have been adapted to bring surgical lasers to endoscopy. However, they deliver a beam that diverges rapidly and requires careful manipulation of the fiber tip relative to the target. Thus, the principal obstacle for surgical lasers in MIS procedures has been a lack of effective control instruments to manipulate the laser in the body cavity and accurately deliver it to the targeted tissue. To overcome this limitation, we have designed and built an endoscopic laser system that incorporates a miniature dual wedge beam steering device, a video camera, and the control system for remote and /or robotic operation. The dual wedge Risley device offers the smallest profile possible for endoscopic use. Clinical specifications and design considerations will be presented together with descriptions of the device and the development of its control system.

  4. 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.

  5. 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. PMID:26167738

  6. Endoscopic laser reshaping of rabbit tracheal cartilage: preliminary investigations

    NASA Astrophysics Data System (ADS)

    Tsang, Walter; Lam, Anthony; Protsenko, Dmitry; Wong, Brian J.

    2005-04-01

    Background: Tracheal cartilage deformities due to trauma, prolonged endotracheal intubation or infection are difficult to correct. Current treatment options such as dilation, laser ablation, stent placement, and segmental resection are only temporary or carry significant risks. The objectives of this project were to design and test a laser activated endotracheal stent system that can actively modify the geometry of tracheal cartilage, leading to permanent retention of a new and desirable tracheal geometry. Methods: Ex vivo rabbit tracheal cartilage (simulating human neonate trachea) were irradiated with an Er: Glass laser, (λ= 1.54um, 0.5W-2.5W, 1 sec to 5 sec). Shape change and gross thermal injury were assessed visually to determine the best laser power parameters for reshaping. A rigid endoscopic telescope and hollow bronchoscope were used to record endoscopic images. The stent was constructed from nitinol wire, shaped into a zigzag configuration. An ex vivo testing apparatus was also constructed. Results: The best laser power parameter to produce shape change was 1 W for 6-7 seconds. At this setting, there was significant shape change with only minimal thermal injury to the tracheal mucosa, as assessed by visual inspection. The bronchoscopy system functioned adequately during testing in the ex vivo testing apparatus. Conclusion: We have successfully designed instrumentation and created the capability to endoscopically reshape tracheal cartilage in an ex vivo rabbit model. The results obtained in ex vivo tracheal cartilage indicated that reshaping using Er: Glass laser can be accomplished.

  7. Endoscopic CO(2) Laser Horizontal Partial Laryngectomy in Larynx Carcinosarcoma

    PubMed Central

    Ciorba, Andrea; Bianchini, Chiara; Iannini, Valeria; Faita, Antonio; Bianchini, Enzo; Stomeo, Francesco; Pelucchi, Stefano; Pastore, Antonio

    2014-01-01

    Background. Carcinosarcoma is an extremely rare malignant neoplasm, with both a malignant epithelial and mesenchymal component, that rarely affects the larynx. Aim. Aim of this paper is to describe the case of a patient affected by a larynx carcinosarcoma treated by endoscopic horizontal partial laryngectomy with CO(2) laser and particularly discuss the histogenetic hypothesis as well as the possible treatment modalities of this rare lesion. Methods. Case report and literature review. Discussion and Conclusion. Still little is known about the biology of carcinosarcoma and there is still no consensus in the literature on the treatment of these tumors. Endoscopic horizontal partial laryngectomy could represent another treatment option in selected cases. PMID:25126435

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

    NASA Astrophysics Data System (ADS)

    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/cm2, 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.

  9. 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. PMID:21806249

  10. Endoscopic goniotomy probe for holmium:YAG laser delivery

    NASA Astrophysics Data System (ADS)

    Joos, Karen M.; Shen, Jin-Hui; Ren, Qiushi

    1994-06-01

    Goniotomy is an effective treatment for primary infantile glaucoma. Because a cloudy cornea may prevent a clear view of the anterior chamber angle through the operating microscope, we investigated whether an endoscope can be combined with a cutting laser to perform laser goniotomy in a surgical model of primary infantile glaucoma. The anterior chambers of cadaver procine eyes were deepened with a viscoelastic material. A 300-micron-diameter silica fiber coupled to an Olympus 0.8-mm-diameter flexible fiber optic endoscope entered the anterior chambers through 4-mm corneal incisions. The anterior chamber angles were clearly observed on a videoscreen as the endoscopic fiber optic laser scalpel approached the pectinate ligaments. With the guidance of a He-Ne aiming beam, the anterior chamber angle pectinate ligaments were cut over a 160 degree arc with a pulsed Ho:YAG laser (2.1 micrometers wavelength, 50 mJ, 5 Hz repetition). The specimens were fixed in glutaraldehyde and processed for scanning electron microscopy, or fixed in formalin and processed for light microscopy. The treated area demonstrated incision of the pectinate ligaments with opening of the underlying trabecular meshwork. The edoscopic fiber optic laser scalpel is capable of cutting the pectinate ligaments in a surgical model of primary infantile glaucoma. Therefore, it may be a useful instrument for performing goniotomy when a cloudy cornea in primary infantile glaucoma prevents visualization of the anterior chamber angle with a goniotomy lens.

  11. 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.

  12. Flexible hollow polycarbonate fiber for endoscopic infrared laser treatment

    NASA Astrophysics Data System (ADS)

    Nakazawa, Masayuki; Shi, Yi-Wei; Iwai, Katsumasa; Matsuura, Yuji; Zhu, Xiao-Song; Miyagi, Mitsunobu

    2007-07-01

    For endoscopic application, inexpensive, safe, and extremely flexible hollow infrared optical fibers have been fabricated based on the polycarbonate (PC) capillary with silver and cyclic olefin polymer (COP) as inner coatings. By optimizing the drawing condition of PC capillary from a commercially available polycarbonate tube and inner-coating process, transmission efficiency of hollow PC fibers is shown to be equal to those of glass capillary based ones. Both Er:YAG laser light and green pilot beam were delivered through the endoscope with low losses even when it was sharply bent with a bending radius as small as 1 centimeter. Preliminary experiments were also conducted on possibility of transmitting infrared thermal image by using bundled silver-coated PC hollow fibers.

  13. Endoscopic photodynamic therapy of tumors using gold vapor laser

    NASA Astrophysics Data System (ADS)

    Kuvshinov, Yury P.; Poddubny, Boris K.; Mironov, Andrei F.; Ponomarev, Igor V.; Shental, V. V.; Vaganov, Yu. E.; Kondratjeva, T. T.; Trofimova, E. V.

    1996-01-01

    Compact sealed-off gold vapor laser (GVL) with 2 W average power and 628 nm wavelength was used for endoscopic photodynamic therapy in 20 patients with different tumors in respiratory system and upper gastrointestinal tract. Russian-made hematoporphyrin derivative (Hpd) `Photohem' was used as a photosensitizer. It was given intravenously at a dose of 2 - 2.5 mg/kg body weight 48 hours prior to tumor illumination with 628 nm light from GVL. Intermittent irradiation with GVL was done through flexible endoscope always under local anaesthesia at a power of 200 - 400 mW/sm2 and a dose of 150 - 400 J/sm2. 80% patients showed complete or partial response depending on stage of tumor. In cases of early gastric cancer all patients had complete remission with repeated negative biopsies. No major complication occurred.

  14. 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.

  15. 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

  16. 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.

  17. [Technological characteristics of endoscopic high frequency current and laser interventions].

    PubMed

    Reidenbach, H D

    1993-01-01

    High frequency current and laser radiation perform two possibilities to generate therapeutic and surgical heat. The integration of these two technologies into endoscopy resulted in important ancillary techniques in the hands of a surgeon. Starting from the principal methods for coagulation and dissection of tissue the respective technological aspects at the interaction of high frequency currents and intensive laser radiation with different wavelengths on biological tissue are illustrated. Mono- and bipolar HF-techniques as well as the light-guide assisted laser method in the contact and non-contact mode are explained. The special problems in endoscopy arising from the reduction in visibility by haemorrhages and the development of smoke at the thermally induced coagulation may be overcome successfully by the simultaneous instillation of a nearly isolating liquid during the HF-treatment. The so-called electrohydrothermosation (EHT) method is presented and several probes and instruments for endoscopic hemostasis and microsurgery are explained. For an increase in safety at the endoscopic application of HF-current the use of the bipolar technique is recommended and several technological developments used in this mode are pointed out. It is shown that the absorption of radiation through the water-content of the tissue is mainly responsible for the reactions which may be produced with laser-light. Furthermore it is mentioned that the range of lasers which might be used has a large spectrum of medical applications which had been even increased especially by the new erbium and holmium solid state lasers.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8147152

  18. Study of fiber-tip damage mechanism during Ho:YAG laser lithotripsy by high-speed camera and the Schlieren method

    NASA Astrophysics Data System (ADS)

    Zhang, Jian J.; Getzan, Grant; Xuan, Jason R.; Yu, Honggang

    2015-02-01

    Fiber-tip degradation, damage, or burn back is a common problem during the ureteroscopic laser lithotripsy procedure to treat urolithiasis. Fiber-tip burn back results in reduced transmission of laser energy, which greatly reduces the efficiency of stone comminution. In some cases, the fiber-tip degradation is so severe that the damaged fiber-tip will absorb most of the laser energy, which can cause the tip portion to be overheated and melt the cladding or jacket layers of the fiber. Though it is known that the higher the energy density (which is the ratio of the laser energy fluence over the cross section area of the fiber core), the faster the fiber-tip degradation, the damage mechanism of the fibertip is still unclear. In this study, fiber-tip degradation was investigated by visualization of shockwave, cavitation/bubble dynamics, and calculus debris ejection with a high-speed camera and the Schlieren method. A commercialized, pulsed Ho:YAG laser at 2.12 um, 273/365/550-um core fibers, and calculus phantoms (Plaster of Paris, 10x10x10 mm cube) were utilized to mimic the laser lithotripsy procedure. Laser energy induced shockwave, cavitation/bubble dynamics, and stone debris ejection were recorded by a high-speed camera with a frame rate of 10,000 to 930,000 fps. The results suggested that using a high-speed camera and the Schlieren method to visualize the shockwave provided valuable information about time-dependent acoustic energy propagation and its interaction with cavitation and calculus. Detailed investigation on acoustic energy beam shaping by fiber-tip modification and interaction between shockwave, cavitation/bubble dynamics, and calculus debris ejection will be conducted as a future study.

  19. 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.

  20. 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.

  1. [Significance of the CO2-laser angle, oral cavity endoscopes].

    PubMed

    Gáspár, L; Bakos, R; Kásler, M

    1991-10-01

    The CO2-laser ray guided at 90 degrees to the surface creates a crater of typical "v" shape. If the guide angle of the ray deviates therefrom and the smaller the angle of incidence than 90 degrees, destruction becomes the more astymmetric, the crater takes an ever more flattened eliptical shape. The lack of tissue becomes even more superficial, thus removal of a circumscribed pathological area requires the sacrifice of more ambient healthy tissue. Consterning the possible angle of incidence of the laser ray instrumental measurements were carried out. It has been ascertained that in the pharinx third of the mouth cavity behind the plain corresponding to the premolars, as a rule, only guide angles below 50 degrees, in the middle third of the mouth cavity corresponding to the area between the front teeth and the molars guide angles between 50-70 degrees, and in the front third mostly a ray guiding below 90 degrees are possible. In the middle and rear third of the mouth cavity the ideal rey-guiding at 90 degrees can be obtained but with reflection, certain areas even cannot be treated directly, are visible but in mirrors. By transforming the hand piece of the laser apparatus endoscopes with fixed mirror and rotating mirror have been constructed. By means of the endoscope with fixed mirror already all parts of the mouth cavity have been rendered accessible while the rotating mirror model became suitable even to admit the laser ray to the surfaces at the ideal angle of incidence of 90(2). PMID:1765203

  2. 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

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

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

    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.

  4. 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

    2015-12-01

    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. PMID:26662067

  5. First experience with blind lithotripsy of ureteral calculi by ruby laser

    NASA Astrophysics Data System (ADS)

    Pupkova, Ludmila S.; Reznikov, Leonid L.; Sokolovsky, Alexander A.; Mursin, A. G.; Soms, Leonid N.; Berenberg, Vladimir A.; Polikarpov, Sergey S.; Parkhomchuk, N. A.; Voskresensky, M. A.

    1994-05-01

    For the last two years we have applied continuous dual-wavelength Nd:YAG 20 - 60 W power laser to various urologic operations. Transmission of laser irradiation via a flexible quartz fiber permitted operating at any depth of the wound. High-intensity irradiation of 1.06 mkm wavelength was effective in making thin incisions into a variety of tissues, including skin, subcutaneous fat, aponeurosis, muscles, urinary bladder wall, prostate gland, renal pelvis, renal capsule and parenchyma, and urethra. The incisions were especially effective if the contact method was used. Operational access was accomplished in 3 - 5 minutes. At the same time, hemostasis occurred in small diameter vessels. More reliable hemostasis could be achieved by means of 1.32 mkm wavelength. With the present laser device, we carried out 57 different urologic operations in our clinic. Examples of such operations include prostatectomy, pyelolithotomy, ureterolithotomy, nephrectomy, resection of renal cysts, condylomata acuminata of the urogenital organs, and papilloma of the urethra and bladder. The results suggest that a combination of these two wavelengths may prove most effective. Advantages of this approach include a decreased blood loss and decreased surgical time, asepsis, good short- and long-term results, and no complications.

  6. Endoscopic Combination Therapy Of Nd:YAG Laser In Conjunction With Conventional Treatments

    NASA Astrophysics Data System (ADS)

    Suzuki, Sohtaro; Aoki, Jun; Shiina, Yasubimi; Miwa, Takeshi; Daikuzono, Norio; Joffe, Stephen N.

    1988-06-01

    In this paper, we discuss the possibilities of the clinical application of the contact method with various endoprobes, either alone or combination with other conventional treat ment such as endoscopic polypectomy, local injection therapy, intubation of prosthesis, radiation therapy and general chemotherapy. According to the type of lesions and the severity of the complicated diseases, endoscopic techniques were chosen and combined. It was generally recognized that all of the endoscopic treatments were not curative therapies but applied as local therapeutics. Therefore, during the management of high risk patients with GI cancer within the mucosa, contact endoscopic Nd:YAG laser therapy should be preferred to general surgery.

  7. 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.

  8. Combined Endoscopic Optical Coherence Tomography and Laser Induced Fluorescence

    NASA Astrophysics Data System (ADS)

    Barton, Jennifer K.; Tumlinson, Alexandre R.; Utzinger, Urs

    Optical coherence tomography (OCT) and laser-induced fluorescence (LIF) are promising modalities for tissue characterization in human patients and animal models. OCT detects coherently backscattered light, whereas LIF detects fluorescence emission of endogenous biochemicals, such as reduced nicotinamide adenine dinucleotide (NADH), flavin adenine dinucleotide (FAD), collagen, and fluorescent proteins, or exogenous substances such as cyanine dyes. Given the complementary mechanisms of contrast for OCT and LIF, the combination of the two modalities could potentially provide more sensitive and specific detection of disease than either modality alone. Sample probes for both OCT and LIF can be implemented using small diameter optical fibers, suggesting a particular synergy for endoscopic applications. In this chapter, the mechanisms of contrast and diagnostic capability for both OCT and LIF are briefly examined. Evidence of complementary capability is described. Example published combined OCT-LIF systems are reviewed, one successful commercial instrument is discussed, and example applications are provided.

  9. Endoscopic Nd:YAG laser treatment of rectosigmoid cancer.

    PubMed Central

    Loizou, L A; Grigg, D; Boulos, P B; Bown, S G

    1990-01-01

    Forty nine patients with rectosigmoid carcinoma considered unsuitable for surgery underwent endoscopic Nd:YAG laser treatment for palliation of symptoms and tumour eradication, if feasible. Altogether 25 (51%) of the lesions had distal margins less than 7 cm from the anus and 36 (73%) extended above the peritoneal reflection. In seven patients with tumours less than 3 cm in diameter, symptomatic improvement was achieved in all (mean follow up 16 months) and complete tumour eradication in three. In the remaining 42 patients with larger tumours (34 greater than 2/3 circumferential, mean length 5.5 cm), symptomatic improvement was achieved with repeated treatments (average 3.4) in 31 (74%) over a mean follow up of 19 weeks. Of the parameters assessed, only circumferential tumour extent proved significant in predicting functional outcome after treatment. All treatment failures (eight initial, three late) occurred in patients with extensive tumours, and only seven of these patients were considered fit for colostomy. Bowel perforation occurred in two patients (5%) but there was no treatment-related mortality. Mean stay in hospital for all laser treatments was nine days (30% were outpatient attendances). These results suggest that laser therapy may be the palliative treatment of choice in patients with rectal carcinoma unsuitable for surgery. PMID:1695161

  10. 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

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

    PubMed Central

    YAN, ZEJUN; XIE, GUOHAI; YUAN, HESHENG; CHENG, YUE

    2015-01-01

    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. PMID:26622508

  12. Endoscopic laser therapy of erosive-ulcerous and inflammatory damages of patients in oncological hospital

    NASA Astrophysics Data System (ADS)

    Efimov, Oleg N.; Kuvshinov, Yu. P.; Poddubny, Boris K.; Kartasheva, E. O.; Ungiadze, G. V.; Ponomarev, Igor V.; Mazurov, S. T.

    1996-01-01

    The results of laser therapy present in 374 patients with erosive-ulcerous and inflammatory damages of respiratory organs and of gastro-intestinal tract after oncological operations. Two types of laser namely endoscopic laser on the basis of He-Ne and Cu laser were used as sources of radiation. It was shown high therapeutic effectiveness of laser therapy. This method may be recommended for the above-mentioned category of the patients.

  13. Use of the flexible fiber CO2 laser in pediatric transcanal endoscopic middle ear surgery.

    PubMed

    Landegger, Lukas D; Cohen, Michael S

    2016-06-01

    We describe 4 pediatric patients (age 6-11 years) who underwent transcanal endoscopic ear surgery (TEES) with the assistance of a flexible fiber CO2 laser over a period of 6 months. Three of these individuals suffered from densely adherent cholesteatoma, where the laser permitted one-handed dissection while preserving endoscopic visualization by limiting bleeding. In the fourth patient, TEES ossiculoplasty was performed for a congenital stapes bar, with subsequent hearing improvement. Advantages and disadvantages of the flexible fiber CO2 laser in the setting of TEES are discussed. Use of the flexible fiber CO2 laser was found to expand the TEES toolkit. PMID:27240515

  14. Laryngocele resection by combined external and endoscopic laser approach.

    PubMed

    Ettema, Sandra L; Carothers, Daniel G; Hoffman, Henry T

    2003-04-01

    Options in the management of laryngoceles include observation, endoscopic resection, and resection via an external approach. We introduce a combined endoscopic and external approach that we have employed on several occasions to ensure complete removal of the laryngocele and the saccule from which it originated. A case is presented to help define the technique. PMID:12731632

  15. A comparative study to analyze the efficacy and safety of flexible ureteroscopy combined with holmium laser lithotripsy for residual calculi after percutaneous nephrolithotripsy

    PubMed Central

    Xu, Gang; Wen, Jiaming; Li, Zhongyi; Zhang, Zhewei; Gong, Xiuqing; Chen, Jimin; Du, Chuanjun

    2015-01-01

    A certain proportion of patients with initial Percutaneous nephrolithotripsy (PCNL) management require ancillary procedures to increase the stone-free rate. In this study, we aim to analyze the efficacy and safety of flexible ureteroscopy combined with holmium laser lithotripsy (F-UL) for treatment of residual calculi after PCNL by comparison with extracorporeal shockwave lithotripsy (SWL). Total of 96 patients with residual renal calculi (4 mm to 20 mm) after PCNL was enrolled from May 2010 to March 2013. They were randomly divided into two groups: US Group: patients were treated with F-UL; SWL Group: patients were treated with SWL. Follow-up was made one month and three months after treatment. The mean residual stone size after PCNL was 12.4 ± 4.3 mm in US group compared with 11.9 ± 4.5 in SWL group. The stone-free rate was 84.7% one month after surgical procedure in US group, this rate increased to 91.3% in the third months, while the stone-free rate in SWL group is 64.6% one month after treatment and 72.9% in the third month. For residual stone in lower calyx, the stone-free rate three month after treatment was 90.4% in US group compared to 65.2% in SWL group (P < 0.05). The overall complication rate was low in both groups, no severe complication was found. Both F-UL and SWL are safe and effective methods for residual calculi after PCNL, without severe complications. F-UL provided significantly higher stone-free rate compared with SWL, especially for low-pole calculi. PMID:26064375

  16. Laser-induced shock wave lithotripsy. Influence of laser pulse energy and irrigation solutions on stone disintegration.

    PubMed

    Hofmann, R; Hartung, R; Schmidt-Kloiber, H; Reichel, E

    1990-01-01

    With a high intensity Q-switched Nd-YAG laser shock waves can be generated in a liquid close to the calculus. Up to 80 mJ single pulse energy with 8 nsec pulse duration can be transmitted through flexible quartz fibers. Energy conversion and enhancement can be accomplished at the fiber tip with optical focussing of the light at the quartz tip, with irrigation solutions and with high pulse energies. Iron-III-dextran solutions (1 mg Fe3+/1) and magnesium chloride (50 mmol/l) increased the pressure in the laser induced breakdown up to ten times (8,000-10,000 bar). Smaller stone particles and higher efficacy in stone fragmentation could be achieved. PMID:1969188

  17. Bacteria Inactivation During Lithotripsy

    NASA Astrophysics Data System (ADS)

    del Sol Quintero, María; Mora, Ulises; Gutiérrez, Jorge; Mues, Enrique; Castaño, Eduardo; Fernández, Francisco; Loske, Achim M.

    2006-09-01

    The influence of extracorporeal and intracorporeal lithotripsy on the viability of bacteria contained inside artificial kidney stones was investigated in vitro. Two different bacteria were exposed to the action of one extracorporeal shock wave generator and four intracorporeal lithotripters.

  18. Endoscopic laser therapy in malignant tracheobronchial obstruction using sequential Nd YAG laser and photodynamic therapy

    PubMed Central

    Moghissi, K.; Dixon, K.; Hudson, E.; Stringer, M.; Brown, S.

    1997-01-01

    BACKGROUND: Because the survival after treatment of advanced inoperable endo-tracheobronchial carcinoma is so poor, a pilot study was undertaken to evaluate the combined cumulative effect on survival of neodymium yttrium aluminium garnet (Nd YAG) laser followed by photodynamic treatment used endoscopically. METHODS: Seventeen patients who presented between January 1992 and March 1996 with inoperable tracheobronchial lesions causing more than 50% endoluminal obstruction were selected to enter the pilot study. Initially they had bronchoscopic Nd YAG laser treatment to debulk the tumour, and this was followed six weeks later by photodynamic therapy to treat the residual tumour. RESULTS: All patients had symptomatic relief and at least a partial response, and seven had a complete response for 3-6 months. Eight of the 17 (47%) survived for at least two years and 11 (65%) survived for a year or more. The median survival of the 10 patients who had died by the time of writing was 18.5 months (range 5-39), 95% confidence interval (CI) 9.9 to 29.5. CONCLUSIONS: Combined Nd YAG laser and endoscopic photodynamic therapy may be an effective palliative treatment for patients with inoperable endotracheobronchial cancer. 


 PMID:9093347

  19. Application Of Endoscopic Lasers For Operations In Gastro-Intestinal Tract

    NASA Astrophysics Data System (ADS)

    Skobelkin, O. K.; Saphronov, A. M.; Shapovalov, A. M.; Zaharov, P. I.

    1988-06-01

    We have described our experience in the application of high energy argon and Nd:YAG lasers for endoscopic surgical manipulations. Laser was used for the removal of polyps with a wide base, villi tumours in colon, for the elimination of scar strictures in colon anastomosis, for the formation of primary-delayed colon anastomosis and for the removal of timoral stenosis in esophagus and in colon. Laser therapy has certain advantages over other endoscopic manipulations: long-term and immediate results are better. One can use this therapy in combination with others (radial therapy, surgical treatment). We have worked out a classification of polyps and stenosing tumours in the digestive system to determine indications for laser endoscopy and to choose the best parameters of laser irradiation.

  20. A laser-scanning endoscope based on polysilicon micromachined mirrors with enhanced attributes

    NASA Astrophysics Data System (ADS)

    George, Markus; Albrecht, Hansjoerg; Schurr, Marc O.; Papageorgas, Panagiotis G.; Hofmann, Ulrich; Maroulis, Dimitris; Depeursinge, Christian D.; Iakkovidis, Dimitris; Theofanous, Nikiforos; Menciassi, Arianna

    2003-10-01

    A miniaturized laser scanning endoscope is presented which makes use of three lasers to illuminate a sample with a red, a green and a blue wavelength simultaneously. Scattered light from the sample is descanned and chromatically separated into the three channels for detection and postprocessing to compose a color image. The scanning subsystem consists of two micro-electro-mechanical mirrors suitable for mass production. The endoscope head can be assembled fast and at low cost. A resolution of the order of 16 lines per mm is achieved for a working distance common in endoscopy. Considerations of the system design include the operation of the mico mirrors, the filtering of reflected light by using polarization effects and a strategy to cope with color metamery. An expert system based on a neural network was found able to analyze endoscopic images to identify suspicious lesions.

  1. 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.

  2. Salivary Stone Pneumatic Lithotripsy in a Live Porcine Model.

    PubMed

    Walvekar, Rohan R; Hoffman, Henry T; Kolenda, Jack; Hernandez, Stephen

    2016-06-01

    The purpose of this study is to evaluate the efficacy of endoscopic fragmentation and removal of artificial calculi in a live porcine model employing intracorporeal pneumatic lithotripsy. In this experimental study, 7 submandibular ducts were accessed and artificial calculi placed. A salivary pneumatic lithotripter probe was inserted through an interventional sialendoscope to fragment the calculi. A salivary duct catheter was then used to flush stone fragments, followed by endoscopy to assess complete fragmentation and ductal trauma. Ultimately, 7 artificial stones (3-10 mm, 4F/5F) were successfully fragmented without causing significant endoluminal trauma. Number of pulses for adequate stone fragmentation averaged 20 (range, 5-31). In all cases, stone fragments were successfully flushed out with the salivary duct catheter. Postprocedure endoscopy confirmed ductal integrity in all 7 ducts. While more studies are needed, this preliminary animal model demonstrates efficacy of endoscopic pneumatic lithotripsy for the management of sialolithiasis. PMID:27048662

  3. Endoscopic removal of a proximal urethral stent using a holmium laser: Case report and literature review

    PubMed Central

    Botelho, Francisco; Thomas, Anil A.; Miocinovic, Ranko; Angermeier, Kenneth W.

    2012-01-01

    Urethral stents were initially developed for the management of urethral strictures and obstructive voiding disorders in select patients. Urethral stent complications are common and may require stent explantation, which is often quite challenging. We present our experience with endoscopic removal of an encrusted UroLume proximal urethral stent in a 72-year-old male using a holmium laser. The literature on various management options and outcomes for urethral stent removal is reviewed. Endoscopic removal of proximal urethral stents is feasible and safe and should be considered as the primary treatment option in patients requiring stent extraction. PMID:23248530

  4. 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.

  5. Correction method of bending loss in the hollow optical fiber for endoscopic submucosal dissection using carbon dioxide laser

    NASA Astrophysics Data System (ADS)

    Kusakari, Daisuke; Hazama, Hisanao; Awazu, Kunio

    2015-03-01

    Endoscopic submucosal dissection using carbon dioxide laser is a promising treatment of early digestive cancer because it can avoid the risk of perforation. Although a hollow optical fiber transmitting mid-infrared light has been used, it was observed that the irradiation effect was influenced by bending a gastrointestinal gastrointestinal endoscope due to the change in transmittance by the bending loss. Therefore, we quantitatively evaluated the change in the irradiation effect by bending the hollow optical fiber in the gastrointestinal endoscope and proposed a correction method to stabilize the irradiation effect. First, the relationship between the irradiated laser energy density and the incision depth for porcine stomach was measured by bending the head of the gastrointestinal endoscope. Next, the relationship between the bending angle of the head of the gastrointestinal endoscope and the temperature rise of the hollow optical fiber in the head of the gastrointestinal endoscope was measured during the laser irradiation. As a result, the laser energy density and the incision depth decreased as the bending angle increased, and linear correlation between the laser energy density and the incision depth was observed. It was found that the bending angle can be estimated by the ratio of the setting laser power to time derivative of the temporal profile of the temperature of the hollow optical fiber. In conclusion, it is suggested that the correction of the laser energy density and stabilization of the incision capability is possible by measuring the temporal profile of the temperature of the hollow optical fiber.

  6. Suture of the mucosa after the endoscopic LASER mucomyotomy of Zenker's diverticulum.

    PubMed

    Minovi, Carolina Morales; Minovi, Amir; Dost, Philipp

    2015-10-01

    The treatment of choice of Zenker's diverticulum is the rigid endoscopic mucomyotomy. At our ENT department, we usually perform an endoscopic mucosal suture after the myotomy. We diagnosed 49 patients and treated 39 patients between 2003 and 2013 due to a Zenker's diverticulum. We used the classification of Brombart to determine the size of the diverticulum. Surgery was performed as an endoscopic LASER mucomyotomy with mucosal sutures or as an open approach with diverticulectomy and myotomy. Patients were phoned to ask for their complaints postoperatively. The symptoms were classified using a visual scale from 0 (no complaint) until 10 (same or more complaints than before the surgery). The distribution of the diverticulum's size was: 6 patients Brombart I, 11 patients Brombart II, 14 patients Brombart III and 18 patients Brombart IV. 10 patients did not undergo surgery. With 33 patients, we performed an endoscopic operation and 6 patients underwent an open approach. The scale of postoperative complaints was the following: 20 patients (0/10), 12 patients (1/10 or 2/10), 3 patients (3/10), 1 patient (6/10) and 1 patient (10/10). None of the patients suffered from severe complications such as mediastinitis. In 85% of the cases, an endoscopic approach could be performed. Postoperatively, 94% of the patients did not have any or just mild complaints. The risk of severe complications or recurrence of the diverticulum is low. The mucosal suture might reduce the risk of infections. PMID:25164870

  7. Treatment of nose, pharynx, larynx, and trachea disorders with Nd:YAG laser through fiber endoscopes

    NASA Astrophysics Data System (ADS)

    Kang, Mengkui; Zhong, Denan; Yang, Shulan

    1993-03-01

    This article is about 203 examples and 14 types of pathological illnesses in the nose, pharynx, and trachea. All these are effectively treated under fiber endoscope with YAG laser, except one example of adenocarcinoma in the nose and pharynx which has relapsed after three times of treatment with rays. The other 202 examples needed only one time of treatment with the rays. The results of the experiment in one to three years is satisfactory.

  8. Endoscopic laser surgery for subglottic and tracheal stenosis

    NASA Astrophysics Data System (ADS)

    Inouye, Tetsuzo; Tanabe, Tetsuya; Nakanoboh, Manabu; Ohmae, Yukio; Ogura, Masami

    1995-05-01

    Seventeen patients with subglottic or tracheal stenosis were treated with laser surgery. Six patients had airway compromise caused by malignant tumors. Sixteen patients required emergency endolaryngeal laser surgery, and satisfactory results were achieved in 12 obtaining an adequate lumen for ventilation. Five patients with airway tumors underwent laser surgery to increase the airway lumen, however, only one patient showed excellent results, with a sufficient airway lumen not being obtained in the other. Airway obstructions due to tumors can be treated satisfactorily by laser surgery, although long term postoperative follow up confirmed recurrence of tumor in most cases.

  9. Fibre-end micro-lens system for endoscopic erbium-laser surgery applications

    NASA Astrophysics Data System (ADS)

    Heifer, D.; Frenz, M.; Romano, V.; Weber, H. P.

    1994-04-01

    A sapphire micro-lens system in combination with a zirconium-fluoride (ZrF4) fibre has been designed and constructed as a surgical tool for focusing Er:YAG-laser radiation. It both refocuses the laser radiation transmitted through a 350 µm core fibre to a spot diameter of 570 µm at a working distance of 7.6 mm, and protects the distal fibre end from damage. An accurate and uncomplicated visualization of the focus position of the erbium-laser beam is realized by coupling a HeNe aiming laser into the cladding of the fibre. In vitro cutting experiments reveal the high cutting precision with minimal thermal damage of the surrounding tissue and the high damage resistance of the system. It may render the use of the erbium laser possible in a wide range of endoscopic applications.

  10. Towards endoscopic ultrafast laser microsurgery of vocal folds.

    PubMed

    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 [micro sign]m below the surface such that larger voids in the active area of vocal fold mucosa (~3×10 mm(2)) 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. PMID:22502583

  11. Flexible ureterorenoscopy (F-URS) with holmium laser versus extracorporeal shock wave lithotripsy (ESWL) for treatment of renal stone <2 cm: a meta-analysis.

    PubMed

    Mi, Yuanyuan; Ren, Kewei; Pan, Haiyan; Zhu, Lijie; Wu, Sheng; You, Xiaoming; Shao, Hongbao; Dai, Feng; Peng, Tao; Qin, Feng; Wang, Jian; Huang, Yi

    2016-08-01

    The objective of the study was to systematically review the efficacy and safety of flexible ureterorenoscopy (F-URS) with holmium laser versus extracorporeal shock wave lithotripsy (ESWL) for the treatment of renal stone <2 cm. A systematic literature review was performed in April 2015 using the PubMed, Embase, Web of Science and the Chinese Biomedical Literature (CNKI and Wanfang) databases to identify relevant studies. All clinical trials were retrieved and their included references investigated. Two reviewers independently assessed the quality of all included studies, and the eligible studies were included and analyzed using the RevMan 5.3 software. Six prospective randomized comparison trials and eight retrospective comparison trials were included, involving a total of 2348 patients. For renal stone 1-2 cm, F-URS technique provided a significantly higher stone-free rate (SFR) [weighted mean difference (WMD) = 2.35, 95 % confidence interval (CI) 1.65-3.34, P < 0.00001], lower auxiliary procedure rate (APR) [odds ratio (OR) 0.33, 95 % CI 0.22-0.50, P < 0.00001] and lower retreatment rate (RR) (OR 0.07, 95 % CI 0.01-0.37, P = 0.002). Similar results were found in the lower pole stone for 1-2 cm subgroup. For renal stone <1 cm, F-URS technique also showed a significantly higher SFR than ESWL (WMD = 2.13, 95 % CI 1.13-4.00, P = 0.02). F-URS is associated with higher SFR, lower APR and RR than ESWL. F-URS is a safe and effective procedure. It can successfully treat patients with stones for 1-2 cm, especially for lower pole stone, without increasing complications, operative time and hospital stay. F-URS can be used as an alternative treatment to ESWL in selected cases with larger renal stones. However, further randomized trials are needed to confirm these findings. PMID:26530230

  12. 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.

  13. Effect of alpha1-blockers on stentless ureteroscopic lithotripsy

    PubMed Central

    Zhu, Jianguo; Liang, Yuxiang; Chen, Weihong; Xu, Shuxiong; Wang, Yuanlin; Hu, Jianxing; He, Hui-chan; Zhong, Wei-de; Sun, Zhaolin

    2016-01-01

    ABSTRACT Objective To evaluate the clinical efficiency of alpha1-adrenergic antagonists on stentless ureteroscopic lithotripsy treating uncomplicated lower ureteral stones. Materials and Methods From January 2007 to January 2013, 84 patients who have uncomplicated lower ureteral stones treated by ureteroscopic intracorporeal lithotripsy with the holmium laser were analyzed. The patients were divided into two groups, group A (44 patients received indwelled double-J stents) and group B (40 patients were treated by alpha1-adrenergic antagonists without stents). All cases of group B were treated with alpha1 blocker for 1 week. Results The mean operative time of group A was significantly longer than group B. The incidences of hematuria, flank/abdominal pain, frequency/urgency after surgery were statistically different between both groups. The stone-free rate of each group was 100%. Conclusions The effect of alpha1-adrenergic antagonists is more significant than indwelling stent after ureteroscopic lithotripsy in treating uncomplicated lower ureteral stones. PMID:27136474

  14. Endoscopic laser-assisted reshaping of collapsed tracheal cartilage: a laboratory study.

    PubMed

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

    1996-03-01

    Repair of anterior tracheal wall collapse is a common and troublesome problem encountered by the head and neck surgeon. The standard treatment calls for an open procedure with or without stenting, depending on the extent of the damage. To avoid the morbidity of the open procedure, a new concept of endoscopic cartilage reshaping was investigated in a laboratory animal study. It involved the application of 1.44-micron pulsed neodymium:yttrium-aluminum-garnet (Nd:YAG) laser at relatively low power to restructure without devitalizing cartilage. An in vivo study was done in six dogs to determine appropriate laser dosimetry in a model of tracheal wall collapse created by a tracheotomy. The deformed cartilage was treated endoscopically with a noncontact 1.44-micron Nd:YAG laser, at 2 to 4 W of power with a repetition rate of 20 Hz, in three animals. As a control, three animals had endoscopic cartilage incisions followed by stent placement. Six weeks postoperatively, both groups had an adequate airway lined by healthy mucosa. In the animals with stenting, however, there was stenosis formation due to scarring at both ends of the stent, with significant inflammatory response in the local area. This study shows that it is possible to use low-power laser energy to reshape cartilage without destroying its viability, and to restore the tracheal wall to a normal contour without ablation or vaporization. The reshaped cartilage will tend to retain its shape with functional elastic force, as seen in in vitro studies. These preliminary results are encouraging, and it seems reasonable to consider using the technique in selected clinical cases as an alternative to conventional open surgery. PMID:8615580

  15. 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.

  16. 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.

  17. Ex vivo pyelotomy, nephroscopy and holmium laser lithotripsy of a staghorn stone in a donor kidney prior to renal transplant

    PubMed Central

    Janczak, Dariusz; Bolanowska, Barbara; Jankowski, Paweł; Dorobisz, Tadeusz; Dorobisz, Karolina; Chabowski, Mariusz; Janczak, Dawid

    2015-01-01

    This case report presents the diagnostic and treatment procedures of stone removal from the kidney of a 67-year-old donor, the transplantation of the kidney to a 65-year-old recipient, and the postoperative course until the end of hospitalization. Computed tomography performed before collecting the organ showed a staghorn stone in the renal pelvis and lower calyces in the right donor kidney. The stones were removed ex-vivo using a rigid ureteroscope and a holmium laser prior to transplantation. Then the organ was transplanted to the left iliac fossa of a 65-year-old man with end-stage renal failure. The authors think there is a possibility of increasing the kidney pool, by using organs containing large calculi. In such cases stones should be removed before the operation and the patient should be monitored regularly, especially in the first months after the transplant. PMID:26240630

  18. Preliminary evaluation of a pulsed 2.15-micron laser system for fiberoptic endoscopic surgery.

    PubMed

    Treat, M R; Trokel, S L; Reynolds, R D; DeFilippi, V J; Andrew, J; Liu, J Y; Cohen, M G

    1988-01-01

    There is a need for lasers that are compatible with fiberoptic endoscopes and that provide greater cutting precision than currently can be produced by the widely used Nd:YAG (1.06 micron) laser. Recently available lasers that operate in the 2-micron region fill this need. This laser light energy can be transmitted by low OH- silica fibers and has much less tissue penetration than radiation at 1.06 micron. We have been evaluating a prototype solid state laser system that produces pulses of 2.15 microns light that is delivered by a silica based fiberoptic delivery system with negligible transmission losses. This system is based on a thulium-holmium-chromium doped YAG (Tm-Ho-Cr: YAG) rod that lases at 2.15 micron. The laser does not require cryogenic cooling, toxic gases, or custom utilities and should be practical in a clinical environment. In vivo animal testing of this laser confirms that it provides greater ablating precision than does the Nd:YAG laser at 1.06 micron. PMID:2839746

  19. Kidney Stone Treatment with Lithotripsy

    MedlinePlus Videos and Cool Tools

    Kidney Stone Treatment with Lithotripsy Broward Health Medical Center Fort Lauderdale, FL November 11, 2011 I'm ... got at least three stones in his left kidney. He's been having pain and blood in his ...

  20. Safety and feasibility of day case ureteroscopy and laser lithotripsy (URSL) in patients with a solitary kidney

    PubMed Central

    Ghosh, Anngona

    2016-01-01

    Introduction The management of nephrolithiasis in patients with a solitary kidney poses a treatment challenge. The study aimed to evaluate the outcomes of ureteroscopy and laser stone fragmentation (URSL) for renal stones in these patients treated in our university teaching hospital. Material and methods Between July 2012 and December 2014, seventeen cases of URSL for stones in a solitary kidney were reviewed. Patient demographics, stone dimensions, perioperative and post-operative outcomes were recorded in a prospectively maintained database. Serum creatinine levels pre-procedure and at follow-up were also compared. Results Seventeen cases of URSL were conducted with a mean age of 52.9 ±19.9 years. 8 of the 17 (47%) patients had stones in multiple locations and 13 (76%) were in the lower pole. The mean ± SD stone size and BMI were 13.0 ±8.9 mm and 31.6 ±5.8 kg/m2, respectively. The stone free rate (SFR) was 82.5%. Fourteen (82.5%) patients were discharged the same day and 16 cases (94%) were discharged within 24 hours. For patients with deranged pre-operative serum creatinine, the mean serum creatinine level improved from 131.2 ±68.3 µmol/L pre-URSL to 106.5 ±36.7 µmol/L at follow-up. There was one Clavien grade II complication with a patient requiring additional antibiotics for post-operative urinary tract infection. There were no other major or minor complications. Conclusions Day case ureteroscopy for stone disease in a solitary kidney is safe and feasible with a low complication rate and an overall improvement in renal function. PMID:27123333

  1. Endoscopic common-path OCT based on sweeping laser source and curled optical patch cord

    NASA Astrophysics Data System (ADS)

    Park, Jae Suk; Jung, Eun Joo; Jeong, Myung Yung; Kim, Chang-Seok; Kang, Jin U.

    2008-02-01

    Several technical problems have to be overcome before Optical Coherence Tomography (OCT) can be accepted among the established endoscopic imaging modalities. Most of conventional Michelson-based OCT systems need to have two separated paths of the sample and reference arms, which limits the flexibility of endoscopic probe. Recently, common-path interferometer based OCT have been demonstrated to circumvent the mismatch problems of length, polarization, and dispersion between the reference and sample arms, but the interferometric scanning methods have been realized with time-domain PZT or spectral-domain CCD. In this work, we demonstrate a novel Fourier-domain common-path OCT based on sweeping laser source, which shows superiority in the speed and robustness. Using a holey optical fiber with low bending loss, a novel curled optical patch cord, like a curl cord of telephone, is also adapted for the convenient access to the biological target at the flexible distance. The freedom to use an arbitrary length and wiring of the probe can provide more flexibility for use in endoscopic OCT.

  2. Outpatient management of esophageal cancer with endoscopic Nd:YAG laser.

    PubMed

    Lightdale, C J; Zimbalist, E; Winawer, S J

    1987-01-01

    In 50 inoperable patients with advanced malignant obstruction of the esophagus, endoscopic Nd:YAG laser treatment was used for palliation of dysphagia. In 30 of these patients, treatment was carried out entirely in an outpatient setting, providing more time at home and saving costs of hospitalization. Most patients had received prior radiation and chemotherapy. All were unable to swallow solid food; 16 had difficulty with liquids. Palliation was achieved in 69% allowing patients to eat a nearly normal diet. Therapy was least successful in cancers involving the cervical esophagus, in cancers more than 8 cm in length, and in cancers that were primarily infiltrating or extraluminal. Epidermoid carcinomas and adenocarcinomas were effectively treated, except for adenocarcinomas of the gastric cardia, which tended to be infiltrating. There were two serious but nonfatal complications, one perforation and one episode of bleeding, directly attributable to Nd:YAG laser therapy. An esophageal dilation prior to endoscopic Nd:YAG laser treatment facilitated outpatient management. PMID:2432776

  3. 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.

  4. Low cost and compact nonlinear (SHG/TPE) laser scanning endoscope for bio-medical application

    NASA Astrophysics Data System (ADS)

    Liu, Jiayun; Lim, Ken Choong; Li, Hao; Seck, Hon Luen; Yu, Xia; Kok, Shaw Wei; Zhang, Ying

    2015-03-01

    Two-photon fluorescence (TPE) and second harmonic generation (SHG) can been used to extract biological information from tissues at the molecular level, which is blind to traditional microscopes. Through these two image contrast mechanisms, a nonlinear laser scanning endoscope (NLSE) is able to image tissue cells and the extra cellular matrix (ECM) through a special fiber and miniaturized scanner without the requirement of poisonous chemical staining. Therefore, NLSE reserves high potential for in-vivo pathological study and disease diagnosis. However, the high cost and bulky size of a NLSE system has become one of the major issues preventing this technology from practical clinical operation. In this paper, we report a fiber laser based multi-modality NLSE system with compact size and low cost, ideal for in-vivo applications in clinical environments. The demonstration of the developed NLSE nonlinear imaging capability on different bio-structures in liver, retina and skin are also presented.

  5. Endoscopic management of post-traumatic prostatic and supraprostatic strictures using Neodymium-YAG laser.

    PubMed

    Nabi, Ghulam; Dogra, Prem Nath

    2002-12-01

    We assessed the feasibility, efficacy and long-term results of endoscopic management using Neodymium-YAG (Nd-YAG) laser as a day care procedure in patients with post-traumatic supraprostatic and prostatic strictures. Three patients with post-traumatic prostatic and supraprostatic obliterative strictures underwent Nd-YAG laser core through urethrotomy as a day care procedure. Patient age ranged between 12 and 14 years. Mean duration of injury was 16 months. The length of stricture was assessed by bi-directional endoscopy prior to the procedure in all cases. Core through procedure was carried out using Nd-YAG laser under the guidance of a cystoscope placed antegradely. Patients were discharged on the same day with urethral catheter. Foley catheters were removed at 6 weeks. Nd-YAG laser core through procedure was carried out successfully in all cases with negligible blood loss in a mean time of 48 min. There were no intraoperative or postoperative complications. Patients were discharged on the same day. Follow-up cystogram was conducted at 6 weeks and urethroscopy at months. At a mean follow-up of 23 months, patients were asymptomatic and voiding well. Nd-YAG laser core through urethrotomy is a safe and effective procedure. It is a less invasive alternative to more complex urethroplasty procedures for patients with post-traumatic prostatic and supraprostatic strictures. It can be carried out as a day care procedure in carefully selected patients and has no complications. PMID:12492959

  6. Focused Ultrasound and Lithotripsy.

    PubMed

    Ikeda, Teiichiro; Yoshizawa, Shin; Koizumi, Norihiro; Mitsuishi, Mamoru; Matsumoto, Yoichiro

    2016-01-01

    Shock wave lithotripsy has generally been a first choice for kidney stone removal. The shock wave lithotripter uses an order of microsecond pulse durations and up to a 100 MPa pressure spike triggered at approximately 0.5-2 Hz to fragment kidney stones through mechanical mechanisms. One important mechanism is cavitation. We proposed an alternative type of lithotripsy method that maximizes cavitation activity to disintegrate kidney stones using high-intensity focused ultrasound (HIFU). Here we outline the method according to the previously published literature (Matsumoto et al., Dynamics of bubble cloud in focused ultrasound. Proceedings of the second international symposium on therapeutic ultrasound, pp 290-299, 2002; Ikeda et al., Ultrasound Med Biol 32:1383-1397, 2006; Yoshizawa et al., Med Biol Eng Comput 47:851-860, 2009; Koizumi et al., A control framework for the non-invasive ultrasound the ragnostic system. Proceedings of 2009 IEEE/RSJ International Conference on Intelligent Robotics and Systems (IROS), pp 4511-4516, 2009; Koizumi et al., IEEE Trans Robot 25:522-538, 2009). Cavitation activity is highly unpredictable; thus, a precise control system is needed. The proposed method comprises three steps of control in kidney stone treatment. The first step is control of localized high pressure fluctuation on the stone. The second step is monitoring of cavitation activity and giving feedback on the optimized ultrasound conditions. The third step is stone tracking and precise ultrasound focusing on the stone. For the high pressure control we designed a two-frequency wave (cavitation control (C-C) waveform); a high frequency ultrasound pulse (1-4 MHz) to create a cavitation cloud, and a low frequency trailing pulse (0.5 MHz) following the high frequency pulse to force the cloud into collapse. High speed photography showed cavitation collapse on a kidney stone and shock wave emission from the cloud. We also conducted in-vitro erosion tests of model and natural

  7. Endoscopic laser surgery of patients with pretumoral diseases and tumors of the organs of respiration and gastro-intestinal tract

    NASA Astrophysics Data System (ADS)

    Poddubny, Boris K.; Ungiadze, G. V.; Kuvshinov, Yury P.; Efimov, Oleg N.; Mazurov, S. T.

    1996-01-01

    The result of treatment of 566 patients with precancerous diseases, cancer and benign tumors of respiratory and gastro-intestinal tract are presented. The `Raduga-1' as a source of laser radiation has been used. The wavelength of radiation 1060 nm. The maximum of basic radiation at the end of lightguide is 50 W. It is shown that the method of endoscopic laser destruction is a highly effective one and may be recommended for radical treatment.

  8. [Adjustable electrohydraulic lithotripsy for minimally invasive ureteroscopic stone treatment].

    PubMed

    Vorreuther, R; Engelking, R

    1992-03-01

    We report on 82 ureteroscopies and electrohydraulic lithotripsies performed with small semirigid ureteroscopes with a minimum outer diameter of 6.5 F and probes of 2.4 F and 3.3 F. Prototypes of new lithotripters were employed, which incorporate infinitely variable energy within a range of 265-1382 mJ per pulse. Increased energy was provided by a rise in voltage, thus modifying the peak pressure and the initial slope of the shock wave. One third of the stones were situated in the upper ureter, 15% in the middle and 46% in the lower ureter. In 54% of these cases previous ESWL (Dornier MFL 5000) had been performed without success. Over 85% of the manipulations were performed under local anesthesia and i.v. sedation. Stone contact was achieved in 99%. Lithotripsy was fully successful in over 90%. The average energy per pulse was 450 mJ. In 7% partial disintegration was achieved and the residual stone was flushed back into the renal pelvis followed by further effective ESWL treatment. One stone had to be removed by open surgery. There were no major complications, such as perforations, due to the electrohydraulic lithotripsy itself. One perforation was caused when the endoscope was advanced into the ureter. No strictures were seen at the 6-month follow-up examination. An indwelling stent was placed in 48% of cases, as the stone burden or an inflamed stone bed suggested this was necessary. We conclude that electrohydraulic lithotripsy with adjustable energy resulting in various peak pressures of the shock wave is a safe and effective method of endoureteral stone treatment. PMID:1561730

  9. 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.

  10. Endoscopic urethrotomy versus urethrotomy plus Nd-YAG laser in the treatment of urethral stricture.

    PubMed

    Vicente, J; Salvador, J; Caffaratti, J

    1990-01-01

    Between February 1987 and May 1988, 30 patients who presented with single, iatrogenic, annular strictures of the bulbar urethra were included in this prospective study. They were randomly divided into two groups; group 1: 15 patients who underwent direct-vision endoscopic urethrotomy (cold-knife incision at 12 o'clock) and group 2: 15 patients who underwent internal urethrotomy plus Nd-YAG laser. The results obtained were analyzed and compared at 1 and 2 years by clinical evaluation, uroflowmetry and retrograde-voiding urethrography. Group 1 obtained 80% good results at 1 year, falling to 60% at 2 years follow-up. Group 2 presented good results in 73.3% both at 1 and 2 years of follow-up. PMID:2261927

  11. 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.

  12. A prospective comparison of laser therapy and intubation in endoscopic palliation for malignant dysphagia.

    PubMed

    Loizou, L A; Grigg, D; Atkinson, M; Robertson, C; Bown, S G

    1991-05-01

    There is little objective long-term follow-up comparing laser therapy with intubation for palliation of malignant dysphagia. In a prospective, nonrandomized two-center trial 43 patients treated with the neodymium:yttrium-aluminum-garnet laser were compared with 30 patients treated by endoscopic intubation; the two groups were comparable for mean age and tumor position, length, and histology. Dysphagia was graded from 0 to 4 (0, normal swallowing; 4, dysphagia for liquids). Pretreatment mean dysphagia grades were similar: laser-treated group, 2.9 (SD, 0.6); intubated group, 3.2 (SD, 0.55). For thoracic esophageal tumors, the percentage of patients achieving an improvement in dysphagia grade by greater than or equal to 1 grade initially and over the long term was similar (laser, 95% and 77%; intubation, 100% and 86%). For tumors crossing the cardia, intubation was significantly better (laser, 59% and 50%; intubation, 100% and 92%, respectively; P less than 0.001). In patients palliated over a long period, however, the mean dysphagia grade over the remainder of their mean dysphagia grade over the remainder of their lives (mean survival: laser, 6.1 months; intubation, 5.1 months) was better in the laser group (1.6 vs. 2.0; P less than 0.01); 33% of laser-treated and 11% of intubated patients could eat most or all solids (P less than 0.05). For long-term palliation, laser-treated patients required on average more procedures (4.6 vs. 1.4; P less than 0.05) and days in the hospital (14 vs. 9; P less than 0.05). The perforation rate was lower in the laser-treated group (2% vs. 13%; P less than 0.02); no treatment-related deaths occurred in either group. For individual patients, the best results are likely to be achieved when the two techniques are used in a complementary fashion in specialist centers. PMID:1707386

  13. Efficacy and safety of endoscopic Nd:YAG laser photocoagulation of flat colorectal adenomas

    NASA Astrophysics Data System (ADS)

    Spinelli, Pasquale; Mancini, Andrea; dal Fante, Marco; Cunsolo, Rocco

    1996-01-01

    The purpose of this study was to evaluate the efficacy and safety of endoscopic Nd:YAG laser photocoagulation for the treatment of flat colorectal adenomas. From January 1982 to December 1994, 222 lesions were treated in 216 patients. Initial eradication was obtained in 96% of lesions with a diameter less than 1 cm, in 89% of lesions with a diameter between 1 and 4 cm, and in 64% of lesions with a diameter greater than 4 cm. According to the histology, a complete disappearance was obtained in 94% of tubular, in 89% of tubulovillous, and in 80% of villous adenomas. Adenomas with severe dysplasia or foci of invasive carcinoma were eradicated in 76% and in 75% of cases, respectively. During a median follow- up of 24 months (3 - 129 months), recurrences developed in 46 of the 186 initially cured lesions (25%). All recurrent lesions were submitted to Nd:YAG laser photocoagulation, obtaining eradication in 37/46 (80%) of the cases. Malignant degeneration occurred in 6% of lesions. Complications related to laser treatments were observed in 5% of patients.

  14. 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

  15. Application of endoscopic Ho:YAG laser incision technique treating urethral strictures and urethral atresias in pediatric patients.

    PubMed

    Futao, Sun; Wentong, Zhang; Yan, Zhuang; Qingyu, Dong; Aiwu, Li

    2006-06-01

    Endoscopic holmium:yttrium-aluminum-garnet (Ho:YAG) laser incision is a new method applied in pediatric urology recent years. To evaluate its therapeutic efficacy on treating the pediatric patients with urethral strictures and urethral atresias, a retrospective study was performed from June 2001 to July 2005 in a total of 28 pediatric patients who underwent endoscopic internal urethrotomy using Ho:YAG laser in our center. In these patients, 25 had urethral strictures and 3 urethral atresias. Follow-up was done ranging from 2 months to 4 years to assess the treatment. Of the 28 patients, 25 (89.3%) have achieved satisfied result without complications following initial incisions. Two patients with urethral atresias and another with long lesion of stricture (> 2 cm) have postoperative stenosis (10.7%). Among the three reoccurred patients, two were successfully reoperated by Ho:YAG laser and open end-to-end anastomosis, respectively. One patient failed to follow-up. With the advantages of safety, efficacy and minimal invasion, endoscopic Ho:YAG laser incision technique could be used as a primary treatment in urethral stricture patients and is worthy to be popularized further in pediatric surgery. PMID:16736220

  16. 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

  17. Compact, transmissive two-dimensional spatial disperser design with application in simultaneous endoscopic imaging and laser microsurgery.

    PubMed

    Metz, Philipp; Adam, Jost; Gerken, Martina; Jalali, Bahram

    2014-01-20

    Minimally invasive surgery procedures benefit from a reduced size of endoscopic devices. A prospective path to implement miniaturized endoscopy is single optical-fiber-based spectrally encoded imaging. While simultaneous spectrally encoded inertial-scan-free imaging and laser microsurgery have been successfully demonstrated in a large table setup, a highly miniaturized optical design would promote the development of multipurpose endoscope heads. This paper presents a highly scalable, entirely transmissive axial design for a spectral 2D spatial disperser. The proposed design employs a grating prism and a virtual imaged phased array (VIPA). Based on semi-analytical device modeling, we performed a systematic parameter analysis to assess the spectral disperser's manufacturability and to obtain an optimum application-specific design. We found that, in particular, a low grating period combined with a high optical input bandwidth and low VIPA tilt showed favorable results in terms of a high spatial resolution, a small device diameter, and a large field of view. Our calculations reveal that a reasonable imaging performance can be achieved with system diameters of below 5 mm, which renders the proposed 2D spatial disperser design highly suitable for use in future endoscope heads that combine mechanical-scan-free imaging and laser microsurgery. PMID:24514122

  18. Extracorporeal shockwave lithotripsy of gallstones. Possibilities and limitations.

    PubMed Central

    Vergunst, H; Terpstra, O T; Brakel, K; Laméris, J S; van Blankenstein, M; Schröder, F H

    1989-01-01

    Recently extracorporeal shockwave lithotripsy (ESWL) has been introduced as a nonoperative treatment for gallstone disease. Except for lung damage, no significant adverse effects of ESWL of gallbladder stones have been observed in animals. In clinical use ESWL of gallbladder stones is now confined to 15% to 30% of symptomatic patients. To achieve complete stone clearance, ESWL of gallbladder stones must be supplemented by an adjuvant therapy. ESWL of bile duct stones is highly effective and can be considered in patients in whom primary endoscopic or surgical stone removal fails. Second generation lithotriptors allow anesthesia-free (outpatient) treatments, but the clinical experience with most of these ESWL devices is still limited. The likelihood of gallbladder stone recurrence is a major disadvantage of ESWL treatment, which raises the issue of cost-effectiveness. ESWL for cholelithiasis is a promising treatment modality with good short-term and unknown long-term results. PMID:2684058

  19. Endoscopic neurosurgery.

    PubMed

    Auer, L M; Holzer, P; Ascher, P W; Heppner, F

    1988-01-01

    This paper describes an ultrasound-guided, laser-assisted, and TV-controlled endoscopic technique which has been used so far in 133 patients for a variety of intracranial lesions. Following CT or MRI image reconstruction, and a decision on the placement of a 1 cm or a 2 cm burrhole, a 1 cm 5.0 mHz or 7.5 mHz intraoperative ultrasound probe is used to direct the endoscope from the burrhole to the target area. A 22.5 cm long rigid endoscope tube with an outer diameter of 6 mm with an inbuilt suction irrigation system, Neodymium Yag laser with 600 micron Quartz glass-fibre and an inlet for various microinstruments is then introduced. The attachment of a TV camera to the ocular lens allows the operator to control further surgical steps in the target area via the TV screen and thus warrants sterility in the operating field. The technique has been used for evacuation of 77 spontaneous intracerebral haematomas (lobar, putaminal, thalamic), 8 traumatic intracerebral haematomas, 13 ventricular haematomas, 8 cerebellar haematomas and 1 brainstem haematoma. Total or subtotal evacuation was achieved in 33% of intracerebral haematomas, removal of more than 50% of the clot in 55%. Twenty-four brain tumours (12 ventricular, 12 cystic cerebral or cerebellar tumours) were operated on for biopsy, evacuation of cyst, resection or removal of the cyst wall and/or laser irradiation of solid tumour or the inner cyst wall of cystic tumours. The complication rate probably related to surgery was 1.6%, morbidity 1.6%, mortality 0%. This high-tec endoscopic technique with its minimal surgical trauma and short operation time can be recommended as a low-risk alternative to conventional neurosurgical techniques. PMID:3278501

  20. Endoscopic treatment of pancreatic calculi.

    PubMed

    Kim, Yong Hoon; Jang, Sung Ill; Rhee, Kwangwon; Lee, Dong Ki

    2014-05-01

    Chronic pancreatitis is a progressive inflammatory disease that destroys pancreatic parenchyma and alters ductal stricture, leading to ductal destruction and abdominal pain. Pancreatic duct stones (PDSs) are a common complication of chronic pancreatitis that requires treatment to relieve abdominal pain and improve pancreas function. Endoscopic therapy, extracorporeal shock wave lithotripsy (ESWL), and surgery are treatment modalities of PDSs, although lingering controversies have hindered a consensus recommendation. Many comparative studies have reported that surgery is the superior treatment because of reduced duration and frequency of hospitalization, cost, pain relief, and reintervention, while endoscopic therapy is effective and less invasive but cannot be used in all patients. Surgery is the treatment of choice when endoscopic therapy has failed, malignancy is suspected, or duodenal stricture is present. However, in patients with the appropriate indications or at high-risk for surgery, endoscopic therapy in combination with ESWL can be considered a first-line treatment. We expect that the development of advanced endoscopic techniques and equipment will expand the role of endoscopic treatment in PDS removal. PMID:24944986

  1. 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

  2. Navigated laser-assisted endoscopic fenestration of a suprasellar arachnoid cyst in a 2-year-old child with bobble-head doll syndrome. Case report.

    PubMed

    Van Beijnum, Janneke; Hanlo, Patrick W; Han, K Sen; Ludo Van der Pol, W; Verdaasdonk, Rudolf M; Van Nieuwenhuizen, Onno

    2006-05-01

    The authors present the case of a 2-year-old boy with bobble-head doll syndrome (BHDS) associated with a large suprasellar arachnoid cyst and enlarged ventricles, who was successfully treated with neuronavigated laser-assisted endoscopic ventriculocystocisternostomy. The clinical history, surgical treatment, and clinical follow up of the patient are described. A navigated laser-assisted endoscopic ventriculocystocisternostomy of the suprasellar arachnoid cyst led to cessation of the head bobbing, and notable reduction of the cyst and ventricles was visible on the postoperative magnetic resonance images. Caused by a suprasellar arachnoid cyst, BHDS can be successfully treated with navigated laser-assisted endoscopic ventriculocystocisternostomy. The advantages of this procedure are minimal invasiveness and facilitated guidance of the neuronavigation system to the target area when normal anatomical landmarks are not visible. PMID:16848093

  3. Endoscopic Cyclophotocoagulation

    PubMed Central

    Seibold, Leonard K.; SooHoo, Jeffrey R.; Kahook, Malik Y.

    2015-01-01

    In recent years, many new procedures and implants have been introduced as safer alternatives for the surgical treatment of glaucoma. The majority of these advances are implant-based with a goal of increased aqueous drainage to achieve lower intraocular pressure (IOP). In contrast, endoscopic cyclophotocoagulation (ECP) lowers IOP through aqueous suppression. Although ciliary body ablation is a well-established method of aqueous suppression, the novel endoscopic approach presents a significant evolution of this treatment with marked improvement in safety. The endoscope couples a light source, video imaging, and diode laser to achieve direct visualization of the ciliary processes during controlled laser application. The result is an efficient and safe procedure that can achieve a meaningful reduction in IOP and eliminate or reduce glaucoma medication use. From its initial use in refractory glaucoma, the indications for ECP have expanded broadly to include many forms of glaucoma across the spectrum of disease severity. The minimally-invasive nature of ECP allows for easy pairing with phacoemulsification in patients with coexisting cataract. In addition, the procedure avoids implant or device-related complications associated with newer surgical treatments. In this review, we illustrate the differences between ECP and traditional cyclophotocoagulation, then describe the instrumentation, patient selection, and technique for ECP. Finally, we summarize the available clinical evidence regarding the efficacy and safety of this procedure. PMID:25624669

  4. Endoscopic cyclophotocoagulation.

    PubMed

    Seibold, Leonard K; SooHoo, Jeffrey R; Kahook, Malik Y

    2015-01-01

    In recent years, many new procedures and implants have been introduced as safer alternatives for the surgical treatment of glaucoma. The majority of these advances are implant-based with a goal of increased aqueous drainage to achieve lower intraocular pressure (IOP). In contrast, endoscopic cyclophotocoagulation (ECP) lowers IOP through aqueous suppression. Although ciliary body ablation is a well-established method of aqueous suppression, the novel endoscopic approach presents a significant evolution of this treatment with marked improvement in safety. The endoscope couples a light source, video imaging, and diode laser to achieve direct visualization of the ciliary processes during controlled laser application. The result is an efficient and safe procedure that can achieve a meaningful reduction in IOP and eliminate or reduce glaucoma medication use. From its initial use in refractory glaucoma, the indications for ECP have expanded broadly to include many forms of glaucoma across the spectrum of disease severity. The minimally-invasive nature of ECP allows for easy pairing with phacoemulsification in patients with coexisting cataract. In addition, the procedure avoids implant or device-related complications associated with newer surgical treatments. In this review, we illustrate the differences between ECP and traditional cyclophotocoagulation, then describe the instrumentation, patient selection, and technique for ECP. Finally, we summarize the available clinical evidence regarding the efficacy and safety of this procedure. PMID:25624669

  5. [Use of a laser beam (YAG) with a flexible fiber for endoscopic treatment of some broncho-tracheal lesions (author's transl)].

    PubMed

    Toty, L; Personne, C L; Hertzog, P; Colchen, A; Lotteau, J; Romanelli, J; Guillet, R; Miro, L; Audebaud, G; Vourc'h, G

    1979-01-01

    For several years we employed an endoscope permitting electro-coagulation in the treatment of some broncho-tracheal lesions and were able to observe the limits and accidents involved in this method. When compared with clinical results (work of Freche in ORL, laser CO2) and after experimental research, the use of a flexible laser beam (YAG) seems to bring about a noteworthy increase in therapeutic possibilities. This flexible fiber beam could easily be used by some medico-surgical teams who already possess appropriate of easily adaptable endoscopic equipment. Clinical studies are in progress. PMID:575806

  6. Use of endoscopic distal attachment cap to enhance image stabilization in probe-based confocal laser endomicroscopy in colorectal lesions*

    PubMed Central

    Ussui, Vivian; Xu, Can; Crook, Julia E.; Diehl, Nancy N.; Hardee, Joy; Staggs, Estela G.; Shahid, Muhammad W.; Wallace, Michael B.

    2015-01-01

    Background and study aims: Colorectal cancer can be prevented through the use of colonoscopy with polypectomy. Most colon polyps are benign or low grade adenomas. However, currently all lesions need histopathologic analysis, which increases diagnostic costs and delays the final diagnosis. Confocal laser endomicroscopy (CLE) is a new technology that enables real-time endomicroscopy. However, there are challenges to maintaining a stable image with currently available systems. We conducted a small study to obtain a preliminary assessment of whether the use of an endoscopic distal attachment cap may enhance image quality of CLE in comparison with images obtained with free-hand acquisition. Patients and methods: Forty outpatients underwent colonoscopy for evaluation of colon polyps in a single academic medical center. Patients were assigned randomly to 1 of 2 study arms on the basis of whether an endoscopic distal attachment cap was used (n = 21, Cap Used) or not used (n = 19, No Cap) in the procedure. The quality of confocal images and probe stabilization was summarized. Results: A total of 81 polyps were identified. The proportion of polyps with images of high quality was 74 % (28/38) in the Cap Used group and 79 % (30/38) in the No Cap arm. Image stability was also similar with and without a cap. Diagnostic accuracy was estimated to be slightly higher in the Cap Used group for probe-based confocal laser endomicroscopy (pCLE; 78 % vs 70 %). This was also true for white-light and narrow-band imaging. Conclusions: This preliminary study did not yield any evidence to support that the use of an endoscopic distal attachment cap improves the quality of images obtained during CLE. PMID:26528511

  7. Endoscopic management of chronic pancreatitis

    PubMed Central

    Oza, Veeral M; Kahaleh, Michel

    2013-01-01

    Chronic pancreatitis (CP) is a common gastrointestinal illness, which affects the quality of life with substantial morbidity and mortality. The management includes medical, endoscopic and surgical approaches with the need for interaction between various specialties, calling for a concerted multidisciplinary approach. However, at the time of this publication, guidelines to establish care of these patients are lacking. This review provides the reader with a comprehensive overview of the studies summarizing the various treatment options available, including medical, surgical and endoscopic options. In addition, technological advances such as endoscopic retrograde cholangiopancreatogrophy, endoscopic shock wave lithotripsy and endoscopic ultrasound can now be offered with reasonable success for pancreatic decompression, stricture dilatation with stent placement, stone fragmentation, pseudocyst drainage, and other endoscopic interventions such as celiac plexus block for pain relief. We emphasize the endoscopic options in this review, and attempt to extract the most up to date information from the current literature. The treatment of CP and its complications are discussed extensively. Complications such as biliary strictures. pancreatic pseudocysts, and chronic pain are common issues that arise as long-term complications of CP. These often require endoscopic or surgical management and possibly a combination of approaches, however choosing amongst the various therapeutic and palliative modalities while weighing the risks and benefits, makes the management of CP challenging. Treatment goals should be not just to control symptoms but also to prevent disease progression. Our aim in this paper is to advocate and emphasize an evidence based approach for the management of CP and associated long term complications. PMID:23330050

  8. Combined laparoscopic pyelolithotomy and endoscopic pyelolithotripsy for staghorn calculi: long-term follow-up results from a case series

    PubMed Central

    Pastore, Antonio Luigi; Palleschi, Giovanni; Silvestri, Luigi; Leto, Antonino; Ripoli, Andrea; Fuschi, Andrea; Al Salhi, Yazan; Autieri, Domenico; Petrozza, Vincenzo; Carbone, Antonio

    2016-01-01

    Purpose: Staghorn renal stones are a challenging field in urology. Due to their high recurrence rates, particularly those associated with an infective process, a complete removal is the ultimate goal in their management. We report our experience with a combined approach of laparoscopic pyelolithotomy and endoscopic pyelolithotripsy, the stone clearance rate, and long-term, follow-up outcomes. Methods: From June 2012 to October 2014, nine adult patients with large staghorn renal calculi (mean size, 7.2 cm; range, 6.2–9.0 cm) underwent a combined laparoscopic and endoscopic approach. The technique comprised laparoscopic pyelolithotomy and holmium-YAG laser stone fragmentation with the use of a flexible cystoscope introduced through a 12 mm trocar. Results: The average operative time was 140 min (range, 90–190 min). The mean estimated hemoglobin loss was 0.6 mmol/l (range 0.5–0.7 mmol/l). None of the patients required an open- surgery conversion. The mean hospital stay was 4 days (range, 2–6 days). A computed tomography urogram control at 6 months of follow up did not show any stone recurrence. Conclusions: Laparoscopic pyelolithotomy combined with endoscopic pyelolithotripsy could be a therapeutic option in cases where mini-invasive procedures, that is, extracorporeal shock wave lithotripsy, ureteroscopic lithotripsy, and percutaneous nephrolithotomy (PCNL) have failed. This technique has a high stone-clearance rate (75–100%) comparable with open surgery and PCNL. However, it could be technically demanding and should be performed by skilled laparoscopy surgeons. PMID:26834835

  9. Sialendoscopy with holmium:YAG laser treatment for multiple large sialolithiases of the Wharton duct: a case report and literature review.

    PubMed

    Sun, Yu-Ting; Lee, Kuo-Sheng; Hung, Shih-Han; Su, Chin-Hui

    2014-12-01

    Sialolithiasis is defined as calcified stone(s) in the salivary duct or glands. Submandibular gland sialolithiasis is the most common (80 to 90%), followed by parotid gland sialolithiasis (5 to 15%). The typical clinical presentation is salivary gland swelling after eating. As the swelling persists, symptoms owing to local inflammation, such as pain and trismus, emerge. In severe cases, cellulitis and even abscess formation occur and subsequently lead to salivary gland atrophy or fistula formation if the sialolithiasis remains untreated. The most common treatment is complete excision of the affected gland together with the stone(s). In some cases, intraoral sialolithotomy is performed when the stone is solitary and easily palpable through the oral cavity. Sialendoscopy is increasingly performed because of its minimal invasiveness. The major limitation of endoscopic laser lithotripsy of the salivary glands is the size of the stone. Often, for a stone larger than 4 mm, multiple fragmentations of the stone into small pieces is necessary before the pieces can be removed by wire basket or grasping forceps. Recently, the holmium:YAG laser has been reported as quite effective in removing larger salivary gland stones. However, sialoendoscopic laser lithotripsy is a very time-consuming procedure and in most cases, when there are multiple large stones in a single gland, entire gland excision is recommended. This report describes a male patient diagnosed with multiple large stones in his left submandibular gland who was successfully treated under sialendoscopy with holmium:YAG laser lithotripsy. PMID:25216563

  10. Comparison of the clinical efficacy and safety of retroperitoneal laparoscopic ureterolithotomy and ureteroscopic holmium laser lithotripsy in the treatment of obstructive upper ureteral calculi with concurrent urinary tract infections.

    PubMed

    Jiang, Jun-Tao; Li, Wei-Guo; Zhu, Yi-Ping; Sun, Wen-Lan; Zhao, Wei; Ruan, Yuan; Zhong, Chen; Wood, Kristofer; Wei, Hai-Bin; Xia, Shu-Jie; Sun, Xiao-Wen

    2016-07-01

    The aim of this study is to compare the clinical efficacy and safety of retroperitoneal laparoscopic ureterolithotomy (RPLU) and ureteroscopic holmium laser lithotripsy (UHLL) as two minimally invasive procedures in managing obstructive upper ureteral calculi with concurrent urinary tract infections (UTI). The retrospective study included 189 patients who underwent unilateral obstructive upper ureteral stones with concurrent UTI from January 2007 to November 2014 at our institution. Patients received RPLU (81 cases) or UHLL (108 cases). All patients received preoperative anti-infection treatment (indwelling ureteral stent and/or preoperative antibiotics). Collected data, including sex, age, stone size, success rate, operation duration, post-operation hospitalization time, and post-operation complications, were compared. All patients were followed up for more than 6 months after surgeries, and no ureterostenosis occurred. The study included 189 patients, 41 (21.7 %) females and 148 (78.3 %) males with a medium age of 52 years (range 22-81 years). All surgeries were successfully performed without conversion to open surgery. Stone size in the RPLU group was larger than that of the UHLL group (16.1 ± 1.4 vs. 10.4 ± 1.6 mm, P = 0.012). Operative duration (P = 0.009) and hospitalization time (P < 0.001) in the UHLL group were significantly shorter than those in the RPLU group, whereas stone clearance rate was significantly higher in the RPLU group (100 vs. 88.9 %, P = 0.002). Of note, postoperative fever was more common in patients treated with UHLL (15 cases) versus RPLU (4 cases) (13.9 vs. 4.9 %, P = 0.043). Moreover, in the UHLL group, three patients without a preoperative indwelling ureteral stent were complicated with sepsis, which was not seen in RPLU group. In our study, the safety and stone clearance rate of RPLU are better than those of UHLL in the treatment of unilateral upper ureteric calculi with concurrent UTI

  11. Cervical Deuk Laser Disc Repair®: A novel, full-endoscopic surgical technique for the treatment of symptomatic cervical disc disease

    PubMed Central

    Deukmedjian, Ara J.; Cianciabella, Augusto; Cutright, Jason; Deukmedjian, Arias

    2012-01-01

    Background: Cervical Deuk Laser Disc Repair® is a novel full-endoscopic, anterior cervical, trans-discal, motion preserving, laser assisted, nonfusion, outpatient surgical procedure to safely treat symptomatic cervical disc diseases including herniation, spondylosis, stenosis, and annular tears. Here we describe a new endoscopic approach to cervical disc disease that allows direct visualization of the posterior longitudinal ligament, posterior vertebral endplates, annulus, neuroforamina, and herniated disc fragments. All patients treated with Deuk Laser Disc Repair were also candidates for anterior cervical discectomy and fusion (ACDF). Methods: A total of 142 consecutive adult patients with symptomatic cervical disc disease underwent Deuk Laser Disc Repair during a 4-year period. This novel procedure incorporates a full-endoscopic selective partial decompressive discectomy, foraminoplasty, and posterior annular debridement. Postoperative complications and average volume of herniated disc fragments removed are reported. Results: All patients were successfully treated with cervical Deuk Laser Disc Repair. There were no postoperative complications. Average volume of herniated disc material removed was 0.09 ml. Conclusions: Potential benefits of Deuk Laser Disc Repair for symptomatic cervical disc disease include lower cost, smaller incision, nonfusion, preservation of segmental motion, outpatient, faster recovery, less postoperative analgesic use, fewer complications, no hardware failure, no pseudoarthrosis, no postoperative dysphagia, and no increased risk of adjacent segment disease as seen with fusion. PMID:23230523

  12. 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.

  13. 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. PMID:25702037

  14. 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.

  15. [Case of renal subcapsular hematoma caused by flexible transurethral lithotripsy].

    PubMed

    Watanabe, Ryuta; Inada, Kouji; Azuma, Kouji; Yamashita, Yokihiko; Oka, Akihiro

    2013-09-01

    A 39-year-old man with macroscopic hematuria was admitted to our hospital. A stone, 5 mm in diameter was detected in the right ureteropelvic junction after abdominal computed tomography and plain abdominal radiography. We performed flexible transurethral lithotripsy (f-TUL) and crushed the stone and extracted almost all stone fragments without any complications. However, almost immediately after the operation, the patient began to complain about pain in the right back. In the results of abdominal plain computed tomography right renal subcapsular hematoma was detected. Because active bleeding was not observed in the results of enhanced computed tomography, only conservative treatment was performed. The patient was discharged from the hospital on day 11 of hospitalization. One month after the operation, plain computed tomography was performed and diminished subcapsular hematoma was detected. Renal subcapsular hematoma is assumed to be a unique complication of extracorporeal shock wave lithotripsy. This is the first report of a case of renal subcapsular hematoma caused by f-TUL. The onset of renal subcapsular hematoma following f-TUL could have been caused either because the laser fiber thrust into the renal lithiasis unintentionally or because the internal pressure of the renal pelvis increased substantially during the operation. PMID:24113753

  16. A review of Thulium fiber laser ablation of kidney stones

    NASA Astrophysics Data System (ADS)

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

    2011-02-01

    The clinical solid-state Holmium:YAG laser lithotripter (λ=2120 nm) is capable of operating at high pulse energies, but its efficient operation is limited to low pulse rates during lithotripsy. The diode-pumped experimental Thulium Fiber Laser (λ=1908 nm) is limited to low pulse energies, but can operate at high pulse rates. This review compares stone ablation threshold, ablation rate, and retropulsion effects for Ho:YAG and TFL. Laser lithotripsy complications also include optical fiber bending failure resulting in endoscope damage and low irrigation rates leading to poor visibility. Both problems are related to fiber diameter and limited by Ho:YAG laser multimode spatial beam profile. This study exploits TFL spatial beam profile for higher power transmission through smaller fibers. A short taper is also studied for expanding TFL beam at the distal tip of a small-core fiber. Stone mass loss, stone crater depths, fiber transmission losses, fiber burn-back, irrigation rates, and deflection through a flexible ureteroscope were measured for tapered fiber and compared with conventional fibers. The stone ablation threshold for TFL was four times lower than for Ho:YAG. Stone retropulsion with Ho:YAG increased linearly with pulse energy. Retropulsion with TFL was minimal at pulse rates < 150 Hz, then rapidly increased at higher pulse rates. TFL beam profile provides higher laser power through smaller fibers than Ho:YAG laser, potentially reducing fiber failure and endoscope damage and allowing greater irrigation rates for improved visibility and safety. Use of a short tapered distal fiber tip also allows expansion of the laser beam, resulting in decreased fiber tip damage compared to conventional fibers, without compromising fiber bending, stone ablation efficiency, or irrigation rates.

  17. 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.

  18. Endoscopic endonasal cranial base surgery simulation using an artificial cranial base model created by selective laser sintering.

    PubMed

    Oyama, Kenichi; Ditzel Filho, Leo F S; Muto, Jun; de Souza, Daniel G; Gun, Ramazan; Otto, Bradley A; Carrau, Ricardo L; Prevedello, Daniel M

    2015-01-01

    Mastery of the expanded endoscopic endonasal approach (EEA) requires anatomical knowledge and surgical skills; the learning curve for this technique is steep. To a great degree, these skills can be gained by cadaveric dissections; however, ethical, religious, and legal considerations may interfere with this paradigm in different regions of the world. We assessed an artificial cranial base model for the surgical simulation of EEA and compared its usefulness with that of cadaveric specimens. The model is made of both polyamide nylon and glass beads using a selective laser sintering (SLS) technique to reflect CT-DICOM data of the patient's head. It features several artificial cranial base structures such as the dura mater, venous sinuses, cavernous sinuses, internal carotid arteries, and cranial nerves. Under endoscopic view, the model was dissected through the nostrils using a high-speed drill and other endonasal surgical instruments. Anatomical structures around and inside the sphenoid sinus were accurately reconstructed in the model, and several important surgical landmarks, including the medial and lateral optico-carotid recesses and vidian canals, were observed. The bone was removed with a high-speed drill until it was eggshell thin and the dura mater was preserved, a technique very similar to that applied in patients during endonasal cranial base approaches. The model allowed simulation of almost all sagittal and coronal plane EEA modules. SLS modeling is a useful tool for acquiring the anatomical knowledge and surgical expertise for performing EEA while avoiding the ethical, religious, and infection-related problems inherent with use of cadaveric specimens. PMID:25323096

  19. [Rigid ureteroscopy and the pulsed laser. Apropos of 325 treated calculi].

    PubMed

    Gautier, J R; Leandri, P; Rossignol, G; Quintens, H; Caissel, J

    1990-01-01

    A pulsed dye laser (Candela) was used in our lithiasis treatment center during the period 02/88-09/89 to remove 325 calculi in 278 patients, requiring 285 endoscopic instrumentations. The pulsed laser allowed to obtain fragmentation of 318 calculi, 238 of which were reduced to thin sand and 80 to coarser fragments. The latter were either cleared using a Dormia probe or further disintegrated by electrohydrolytic shock wave treatment or extracorporeal shock wave lithotripsy (ESWL). No complication imputable to laser stone fragmentation was noted. Failure of stone clearance was chiefly due to the nature and shape of the stone (black, smooth monohydrated calcium oxalate calculi). The thinness of the laser fiber has made it possible to use small caliber ureteroscopes, thereby increasing the reliability of ureteroscopy. Coupled with ESWL (EDAP LT01), this technique has caused the rate of open surgical removal of ureter confined calculi to fall from 11% to 1%. PMID:2212706

  20. 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].

  1. Endoscopic ultrasound

    MedlinePlus

    Endoscopic ultrasound is a type of imaging test. It is used to see organs in and near the digestive ... Ultrasound is a way to see the inside of the body using high-frequency sound waves. Endoscopic ...

  2. Cleaning of endodontic root canal by ultrasonics and Nd:YAG laser beam with fiber optic delivery: scanning electron microscopy, endoscopic and microradiographic analysis

    NASA Astrophysics Data System (ADS)

    Berna, Norberto; Melis, Marco; Benvenuti, Alessandro; Tosto, Sebastiano; Pierdominici, Fabrizio

    1997-05-01

    12 teeth have been extracted and treated 'in vitro' by ultrasonics and Nd:YAG pulsed laser with fiber optic delivery to compare the cleaning efficiency of the root canal. The optic fiber was equipped with a water-air coaxial cooling system. The ultrasonic device was equipped with a 3 percent NaCl solution douche system. The samples have been prepared according to the technical specifications of the suppliers of laser and ultrasonics and observed by an endodontic endoscope. Cross sections of the samples have been utilized for microradiographic investigations and scanning electron microscopy observations. Local melting has been observed after laser irradiation.Also, vitrification preferentially occurred in the apical zones. The occurrence of vitrification was found strongly dependent on the translation velocity of the laser beam inside the root canal. The laser beam has shown a cleaning efficiency greater than that obtained by ultrasonic procedure.

  3. Percutaneous endoscopic management of intrahepatic stones in patients with altered biliary anatomy: A case series.

    PubMed

    Bhandari, Suryaprakash; Bathini, Rajesh; Sharma, Atul; Maydeo, Amit

    2016-03-01

    Incidence of primary intrahepatic stones (IHS) in India is very less as compared to the Far East. However patients with altered biliary anatomy are prone for IHS formation secondary to anastomotic stricture formation. Indian data on percutaneous endoscopic management of IHS is scare. Five patients with IHS were managed percutaneously. All patients had undergone Roux-en-Y hepaticojejunostomy and were not suitable for direct endoscopic intervention. All patients underwent percutaneous biliary drainage followed by cholangioscopy-guided laser lithotripsy. Crushed stones were pushed across the anastomotic site using basket/balloon and ductal clearance was achieved. Good stone pulverization could be achieved in five patients (100 %). Complete ductal clearance could be achieved in all patients (100 %). Cholangioscopy-guided treatment of IHS can be valuable alternative to surgery in select group of patients especially those having dilated biliary tree with absence of intrahepatic strictures. However long-term follow up studies are required to see for recurrence of stone formation. PMID:27041379

  4. Nd:YAG laser treatment for benign lesions of vocal cord through fiber endoscope

    NASA Astrophysics Data System (ADS)

    Pin, Wei-Zheng

    1993-03-01

    This paper describes 120 cases with benign lesions of the vocal cord, such as the polyp and the nodule, treated by laser irradiation and application of Nd:YAG laser and optical fiber carried out through fiber laryngoscope under surface anaesthesia. One-hundred-eleven of the cases were cured, 9 improved, and 0 failed. This method is superior to other methods and has the following features: accuracy, rapidity, non-bleeding, painlessness, easy operation, rare complication, and good effect.

  5. Endoscopic removal of PMMA in hip revision surgery with a CO2 laser

    NASA Astrophysics Data System (ADS)

    Sazy, John; Kollmer, Charles; Uppal, Gurvinder S.; Lane, Gregory J.; Sherk, Henry H.

    1991-05-01

    Purpose: to compare CO2 laser to mechanical means of PMMA removal in total hip arthroplasty revision surgery. Materials and methods: Forty-five patients requiring hip revision surgery were studied and compared to historical controls. Cement was removed from the femoral canal utilizing a 30 centimeter laparoscope. A CO2 laser waveguide was passed through the laparoscope into the femoral canal and a TV camera was placed over the eye piece to permit visualization of the depths of the femoral canal on a video monitor. The leg was placed in a horizontal position which avoided the pooling of blood or saline in the depths of the femur. Under direct vision the distal plug could be vaporized with a 40 centimeter CO2 laser waveguide. Power settings of 20 to 25 watts and a superpulsed mode were used. A 2 mm suction tube was welded to the outside of the laparoscope permitting aspiration of the products of vaporization. Results: Of 45 hip revisions there were no shaft perforation, fractures or undue loss of bone stock. There was no statistically different stay in hospital time, blood loss or operative time between the CO2 revision group compared to the non-laser revision group, in which cement was removed by mechanical methods. Conclusions: Mechanical methods used in removing bone cement using high speed burrs, reamers, gouges, and osteotomies is technically difficult and fraught with complications including shaft fracture, perforations, and unnecessary loss of bone stock. The authors' experience using the CO2 laser in hip revision surgery has permitted the removal of bone cement. Use of a modified laparoscope has allowed for precise, complete removal of bone cement deep within the femoral shaft without complication or additional operative time. The authors now advocate the use of a CO2 laser with modified laparoscope in hip revision surgery in which bone cement is to be removed from within the femoral shaft.

  6. Optimizing Shock Wave Lithotripsy: A Comprehensive Review

    PubMed Central

    McClain, Paul D; Lange, Jessica N; Assimos, Dean G

    2013-01-01

    Shock wave lithotripsy is a commonly used procedure for eradicating upper urinary tract stones in patients who require treatment. A number of methods have been proposed to improve the results of this procedure, including proper patient selection, modifications in technique, adjunctive therapy to facilitate elimination of fragments, and changes in lithotripter design. This article assesses the utility of these measures through an analysis of contemporary literature. PMID:24082843

  7. Endoscopic mucosal incision by diode laser for early cancer treatment in the alimentary tract: effect of submucosal indocyanine green solution injection

    NASA Astrophysics Data System (ADS)

    Hayashi, Takuya; Arai, Tsunenori; Nakamura, Naoko; Tajiri, Hisao; Miura, Soichiro; Kikuchi, Makoto

    1999-06-01

    Mucosal incision technique by diode laser ablation was studied to ensure the operation of endoscopic mucosal resection (EMR), which is gold standard method for early gastric cancer with little/no risk of lymphnode metastasis. Our method was designed to facilitate grasping a large lesion by hitching the snaring wire on the incised mucosal groove around the lesion. We employed local submucosal injection of indocyanine green (ICG) solution. ICG solution was used to prevent direct laser light penetration to the muscularis propriae owing to strong absorption of 805nm light (absorption coefficent at 805 nm is about 200cm-1). We used diode laser radiation with an output of 25W by contact (0.1, 0.5, 1.0 kg/cm2) and non-contact irradiation methods. In the preliminary experiment with resected porcine stomach, muscularis propriae was intact by the 60s non-contact irradiation or the 8s contact irradiation with contact pressure of 1kg/cm2. In the endoscopic experiment we used 3 dogs. Using conical contact probe, we successfully demonstrated 3cm diameter circular incision with sharp groove in 10 minutes. We could place the snaring wire on the incised groove. Histology of the endoscopically incised canine stomach revealed that the submucosal layer welled up to 6mm in thickness and the bottom of the incision groove reached 1.9mm at deepest below the mucosal muscle. The thickness of the coagulation layer around the incised groove was up to 1.8mm. No damage was seen a the muscularis propriae. We demonstrate easy as well as sure snaring by using our laser incision technique. We think our technique may be available to enhance the efficacy of EMR for early gastric cancer including the lesion over 2cm in diameter.

  8. Retrospective measures on applying endoscopic YAG laser to treat alimentary canal diseases from 1983 to 1995

    NASA Astrophysics Data System (ADS)

    Wang, Rui-Zhong; Wu, Ning-Xiao; Gao, Su-ping; Rong, Zeng-Qin

    1996-05-01

    It was in 1983 when we started to apply YAG laser to do experiments on animal and fresh internal organs off the body to confirm its effectiveness. Then we started to use it in clinical practice. Up to October 1995, in the twelve years, we treated 1075 cases, 2574 person times. Seven-hundred-seventy-nine cases of various esophagostenosis. Four-hundred-fifty-six of them were malignant stenosis, 295 anastomostenosis, 15 stenosis after radiotherapeutics, 7 corrosive anastomostenosis, 6 inflammatory anastomostenosis, plus we cured 5 cardia losses of relax, and 241 polyps in the alimentary canal. Among the 2154 polyps cured, 6 were that of esophagus, 6 that of cardia, 25 that of stomach, 10 that of duodenum, 194 that of large intestine. In addition, we treated 15 alimentary canal bleeding and 35 malignant colon and tectum cancers. Our experience in laser operating on the coelom has become richer and richer. The methods we used are being widened. The range of our laser application is being enlarged. We have gained our own experience in preventing complications and keeping the endoscopy from being damaged. The cure rate of the non-malignant had raised up to 98.7%. Cure rate of the malignant had raised up to 91%. The alimentary canal polyps can be cured perfectly. It is hard to tell whether YAG laser or high frequency electroresection has the advantage over the other. Besides, this paper is going to put forward several questions to discuss.

  9. Miniaturized optical fiber endoscope without inertial scan for simultaneous imaging and laser microsurgery

    NASA Astrophysics Data System (ADS)

    Adam, Jost; Metz, Philipp; Gerken, Martina; Jalali, Bahram

    2013-09-01

    The current autostereoscopic projection system is accomplished by array projectors. It is easy to realize optically but has a drawback with size. Another type is to place the shutter on the screen. It saves the volume but reduces the efficiency depending on how many views are produced. The shutter in the lens aperture has the same efficiency problem, too. To overcome these problems, a full HD autostereoscopic projector based on the lens aperture switching type is proposed. It has RGB laser sources and can produce 16-views or even higher stereoscopic images. This system removes the shutter in the lens aperture by the opti-mechanism itself. The specific light on the lens aperture coming from the point on the DMD is reflected to different angles. The proper angle of light is generated in the object side by the relay and folding system. The UHP lamps or the LED rays are difficult to constrain in a relative small cone angle. For this reason, the laser is applied to the design. The very small etendue of the laser is good for this architecture. The rays are combined by dichroic filter from RGB laser sources then forming and expanding to the mirror. The mirror is synchronized with DMD by the DSP control system. The images of different views are generated by DMD and specific position of the mirror. By the double lenticular screen, the lens aperture is imaged to the observer's viewing zone and the 3D scene is created.

  10. [The role of the laser in urology].

    PubMed

    Anidjar, M; Cussenot, O; Ravery, V; Teillac, P; Le Duc, A; Boccon-Gibod, L

    1995-04-01

    There is currently a renewed interest in laser in the field of urology, essentially for the treatment of benign prostatic hypertrophy, as a result of recent developments in the field of fibres. Laser is light coherent in time and space emitted continuously or in pulses. Only its thermal and photochemical properties are used in urology. Endoscopic coagulation of superficial bladder tumours by Nd YAG laser does not seem to be better than classical endoscopic resection, at the present time, as although it is less haemorrhagic, it does not decrease the recurrence rate. Photochemotherapy of bladder carcinoma in situ still constitutes a complex treatment protocol reserved for specialized centres. Lastly, upper urinary tract tumours can be treated by Nd YAG laser coagulation, in rare indications which are the same as those of ureteroscopic or percutaneous resection. The recent development of lateral firing laser fibres and contact tip fibres has led to a renewed interest in laser in benign prostatic hypertrophy. Two different techniques have been proposed: Nd YAG laser coagulation under direct visual or ultrasound control (TULIP), which gives delayed objective results (two or three months) and contact tissue vaporization (Nd YAG, diode), whose effects are more immediate. In both cases, intraoperative bleeding is minimal and the length of hospital stay is decreased, but the duration of urine drainage remains to be defined. Endoscopic pulsed laser urinary lithotripsy (dye, Ho YAG), although effective and atraumatic, is not justified at the present time because of its high cost compared to mechanical percussion lithotripters. Lastly, laser treatment for urethral stricture has not been found to be superior to classical scalpel urethrotomy and laser tissue welding is still in the experimental stages. In conclusion, laser technology, especially fibers, has currently reached an important phase of development with applications for urological disease, essentially in the treatment

  11. Comparison of urinary calculus fragmentation during Ho:YAG and Er:YAG lithotripsy

    NASA Astrophysics Data System (ADS)

    Kang, Hyun Wook; Lee, Ho; Teichman, Joel H.; Welch, A. J.

    2005-04-01

    We compared urinary calculus fragmentation with long pulsed Ho:YAG (λ= 2.12 μm) versus Er:YAG (λ = 2.94 μm) lasers. We measured the ablation width, depth, volume and efficiency as a function of pulse energy from calculus threshold energy to clinical energy typically used for Ho:YAG laser lithotripsy. Ablation effects were evaluated for three types of urinary calculi (calcium oxalate monohydrate, cystine, and uric acid), for single and multiple pulses applied at various optical energy levels. By means of comparing laser-induced crater topography and ablation volume for each stone type, the feasibility of Er:YAG laser lithotripsy was appraised. The Er:YAG laser pulse energy generated deeper and narrower crater shapes with relatively smooth contours whereas the Ho:YAG laser produced shallower and wider craters with irregular shapes. In terms of multiple pulses ablation, the Er:YAG produced larger ablation volume than Ho:YAG. The deeper crater induced by the Er:YAG was attributed to the higher absorption coefficient of stones at the 2.94 μm wavelength, and widening of crater by Ho:YAG was perhaps caused by lateral expansion of ablated material. Comparing the ablation efficiency, Er:YAG was superior to Ho:YAG for both single and five-pulses.

  12. Treatment for intranasal synechiae by CO2 laser under endoscopic visualization

    NASA Astrophysics Data System (ADS)

    Feng, Yunhai; Yin, Shankai

    2005-07-01

    Endonasal low intensity laser therapy (ELILT) began in China in 1998. Now in China it is widely applied to treat hyperlipidemia and brain diseases such as Alzheimer's disease, Parkinson's disease, insomnia, poststroke depression, intractable headache, ache in head or face, cerebral thrombosis, acute ischemic cerebrovascular disease, migraine, brain lesion and mild cognitive impairment. There are four pathways mediating EILILT, Yangming channel, autonomic nervous systems and blood cells. Two unhealth acupoints of Yangming channal inside nose might mediate the one as is low intensity laser acupuncture. Unbalance autonomic nervous systems might be modulated. Blood cells might mediate the one as is intravascular low intensity laser therapy. These three pathways are integrated in ELILT so that serum amyloid β protein, malformation rate of erythrocyte, CCK-8, the level of viscosity at lower shear rates and hematocrit, or serum lipid might decrease, and melanin production/SOD activity or β endorphin might increase after ELILT treatment. These results indicate ELILT might work, but it need to be verified by randomized placebo-controlled trial.

  13. Computed tomographic evaluation of gallstone calcification for biliary lithotripsy.

    PubMed

    Caslowitz, P L; Fishman, E K; Kafonek, D R; Lillemoe, K D; Mitchell, S; Widlus, D M; Saba, G P

    1991-04-01

    As the Food and Drug Administration trials for biliary lithotripsy in the United States near completion, future criteria for patient eligibility remain to be defined. Gallstone calcification greater than 3-mm partial rim on plain film (KUB) or oral cholecystogram (OCG) has excluded patients thus far, since early results of gallstone clearance (lithotripsy plus chemodissolution) were suboptimal with calcified stones. To evaluate the usefulness of these criteria for gallstone fragmentation, computed tomographic (CT) scans were performed on 20 patients immediately prior to lithotripsy to evaluate gallstone density and 24 hours after lithotripsy to observe the CT appearance of fragmentation. The adequacy of fragmentation was determined by pre- and post-lithotripsy sonography. This report constitutes the results of these investigations. PMID:10149158

  14. Complications of non-endoscopic percutaneous laser disc decompression and nucleotomy with the neodymium: YAG laser 1064 nm.

    PubMed

    Hellinger, J

    2004-10-01

    In this review, we discuss how nonendoscopic percutaneous laser disc decompression (PLDD) and nucleotomy, using the YAG laser 1064, now has reinforced itself as a minimally invasive procedure in discogenic, vertebral pain syndromes, created by bulging, protrusions, and contained and uncontained extrusions in all areas of the spine. The rate of complication is an important criterion of the application of this new method. 3377 patients were treated with this method in the period of November 11, 1989 to April 30, 2002. While 356 patients' cervical spine was operated on, a further 38 patients had their thoracic spine operated on. Six weeks later, a prospective, consecutive control followed with an uninterrupted recording. Subsequently, all complications that occurred in this time frame were recorded. A comparison was carried out between the complication rate as covered by the literature of other intradiscal percutaneous methods and open disc surgery. Using the Nd-YAG laser 1064 nm, PLDD is generally evaluated with a complication rate of 0.5%. In the cervical spine area, the complication rate was 1.0%. No significant complications followed the thoracic intervention. In comparison to figures suggested by the relevant literature regarding possible complications with other procedures, this particular procedure is relative risk-free. In conjunction with the satisfying results regarding pain and paralysis removal, the extraordinarily low complication density of Nd-YAG PLDD culminates in the recommendation that the procedure should be applied to patients who are between unsuccessful conservative therapy and other operative methods. PMID:15671715

  15. Retrospective analysis of a combined endoscopic and transcutaneous technique for the management of parotid salivary gland stones.

    PubMed

    Numminen, Jura; Sillanpää, Saara; Virtanen, Jussi; Sipilä, Markku; Rautiainen, Markus

    2014-01-01

    Sialendoscopy is used in the diagnosis and treatment of various symptoms relating to the salivary gland, e.g. chronic swelling or obstruction and inflammation of the salivary duct. Small intraductal stones can be removed with various instruments during sialendoscopy, whereas larger ones can be fragmented with extracorporeal shockwave lithotripsy or laser. However, 5-10% of the patients with parotid stones cannot be treated with these methods. In patients with large impacted stones or stones in a hilus area, a combined endoscopic and transcutaneous technique can be employed. The stone is approached endoscopically, a skin flap is raised over or a small incision is made through the illuminated area, and the stone is removed by an external route with minimal morbidity. This retrospective study analysed the cases of 8 patients treated using the combined technique, 6 of whom became symptom free. Superficial parotidectomy was performed in 1 patient. No complications were observed, and ductal stents were not used. The average diameter of the stones was 7.6 mm (range 7.0-10.2). The combined technique is recommended for the removal of large and impacted intraductal stones in the parotid gland. No major complications have been reported. PMID:25500629

  16. Endoscopic palliation of colorectal benign and malignant tumors: YAG laser therapy

    NASA Astrophysics Data System (ADS)

    Norberto, Lorenzo; Ranzato, Riccardo; Marino, Saverio; Angriman, Imerio; Vella, Vincenzo; Donadi, Michele; D'Amico, D. F.

    1997-12-01

    From November 1, 1992 to January 31, 1997, we treated 189 pts: 113 males and 76 females, of mean age 67 yrs. 148 pts were affected with colo-rectal cancer and 41 pts with extensive carpet benign tumors. Tumor location was: rectum in 115 pts, recto-sigmoid joint in 31 pts, colo-rectal anastomosis in 25 pts, sigmoid colon in 15 pts, descending colon in 2 pts and cecum in 1 pt. 26 pts were treated with diathermo-therapy, 15 pts with dilatation, 12 pts with radiotherapy, 5 pts with chemotherapy, 1 pt with chemotherapy and radiotherapy. Yag-laser palliation gave good results in 90% (170 - 189) with an average survival of 24 weeks; there were complications due to the treatment in due pts (1%) without hospital mortality.

  17. Patient and personnel exposure during extracorporeal lithotripsy.

    PubMed

    Glaze, S; LeBlanc, A D; Bushong, S C; Griffith, D P

    1987-12-01

    Extracorporeal shock wave lithotripsy (ESWL) has provided a nonsurgical approach to treatment of renal stones. The Dornier lithotripter uses dual image intensified x-ray systems to center the stone before treatment. Three imaging modes are offered: a fluoroscopic mode and two video spot filming modes. The average entrance exposure to the stone side of the typical patient at our facility is 2.6 X 10(-3) C kg-1 (10 R) [range: 0.5-7.7 X 10(-3) C kg-1 (2-30 R)] which is comparable and often much less than that reported for percutaneous lithotripsy. Recommendations are made for minimizing patient exposure. Scattered radiation levels in the lithotripter room are presented. We have determined that Pb protective apparel is not required during this procedure provided x-ray operation is temporarily halted should personnel be required to lean directly over the tub to attend to the patient. If the walls of the ESWL room are greater than 1.83 m (6 feet) from the tub, shielding in addition to conventional construction is not required. PMID:3679826

  18. [TRANSURETHRAL CONTACT URETERAL LITHOTRIPSY IN A GASEOUS (CO2) MEDIUM].

    PubMed

    Glybochko, P V; Aljaev, Ju G; Rapoport, L M; Carichenko, D G; Arzumanjan, E G

    2015-01-01

    The paper describes for the first time the method of contact ureteral lithotripsy in gaseous (CO2) medium. It presents the results of a comparative study of urolithiasis patients treated with this treatment modality (study group, n=30) and with traditional contact ureteral lithotripsy in liquid medium (control group, n=30). The incidence of retrograde migration of calculus in the kidney in the study group was 0%, while it was 16.6% in the control group. Acute or exacerbation of chronic pyelonephritis was diagnosed in only 3 (10%) patients in the control group. The suggested method of contact ureteral lithotripsy is safe and provides several advantages over traditional contact ureteral lithotripsy in a fluid medium, such as: physiologic validity, absence of calculus hypermobility (increased mobility), improved visualization during surgery and high cost effectiveness. PMID:26237808

  19. [Using safocid for antibiotic prophylaxis in minimally-invasive endoscopic operations and manipulations].

    PubMed

    Proskurin, A A; Asfandiiarov, F R; Kalashnikov, E S; Miroshnikov, V M

    2010-01-01

    Efficacy of safocid (1 g of seknidasol, 1 g of azitromycin, 150 mg of fluconasol) was studied in antibiotic prophylaxis before conduction of urological endoscopic operations: diagnostic cystoscopy, renal stenting, ureteroscopy with contact lithotripsy. A total of 128 patients of the urological department received a single safocid dose 90 min before surgical intervention. Safocid efficacy in prevention of infectious complications reached 96.2%. PMID:21427992

  20. Outcome of probe-based confocal laser endomicroscopy (pCLE) during endoscopic retrograde cholangiopancreatography: A single-center prospective study in 45 patients

    PubMed Central

    Lönnebro, Ragnar; Stigliano, Serena; Haas, Stephan L; Swahn, Fredrik; Enochsson, Lars; Noel, Rozh; Segersvärd, Ralf; Chiaro, Marco Del; Verbeke, Caroline S; Arnelo, Urban

    2015-01-01

    Background Diagnosis of pre-malignant and malignant lesions in the bile duct and the pancreas is sometimes cumbersome. This applies in particular to intraductal papillary mucinous neoplasia (IPMN) and bile duct strictures in primary sclerosing cholangitis (PSC). Aims To evaluate in a prospective cohort study the sensitivity and specificity of probe-based confocal laser microscopy (pCLE) during endoscopic retrograde cholangiopancreatography (ERCP). Methods We performed pCLE together with mother-baby endoscopy (SpyGlass) during 50 ERCP sessions in 45 patients. The Miami and Paris criteria were applied. Clinical diagnosis via imaging was compared to pCLE and the final pathological diagnosis from surgically-resected, biopsy, or cytology specimens. Patients were followed up for at least 1 year. Results We were able to perform pCLE in all patients. Prior to endoscopy, the diagnosis was benign in 23 patients and undetermined (suspicious) in 16 patients, while six patients had an unequivocal diagnosis of malignancy. Sensitivity was 91% and specificity 52%. The positive (PPV) and negative predictive value (NPV) was 82% and 100%, respectively. Apart from mild post-ERCP pancreatitis in two patients, no complications occurred. Conclusions Our study showed that pCLE is a safe, expert endoscopic method with high technical feasibility, high sensitivity and high NPV. It provided diagnostic information that can be helpful for decisions on patient management, especially in the case of IPMN and unclear pancreatic lesions, in individuals whom are at increased risk for pancreatic cancer. PMID:26668748

  1. Endoscopic therapy in chronic pancreatitis: current perspectives.

    PubMed

    Seicean, Andrada; Vultur, Simona

    2015-01-01

    Endoscopic therapy in chronic pancreatitis (CP) aims to provide pain relief and to treat local complications, by using the decompression of the pancreatic duct and the drainage of pseudocysts and biliary strictures, respectively. This is the reason for using it as first-line therapy for painful uncomplicated CP. The clinical response has to be evaluated at 6-8 weeks, when surgery may be chosen. This article reviews the main possibilities of endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic ultrasound (EUS) therapies. Endotherapy for pancreatic ductal stones uses ultrasound wave lithotripsy and sometimes additional stone extractions. The treatment of pancreatic duct strictures consists of a single large stenting for 1 year. If the stricture persists, simultaneous multiple stents are applied. In case of unsuccessful ERCP, the EUS-guided drainage of the main pancreatic duct (MPD) or a rendezvous technique can solve the ductal strictures. EUS-guided celiac plexus block has limited efficiency in CP. The drainage of symptomatic or complicated pancreatic pseudocysts can be performed transpapillarily or transgastrically/transduodenally, preferably by EUS guidance. When the biliary stricture is symptomatic or progressive, multiple plastic stents are indicated. In conclusion, as in many fields of symptomatic treatment, endoscopy remains the first choice, either by using ERCP or EUS-guided procedures, after consideration of a multidisciplinary team with endoscopists, surgeons, and radiologists. However, what is crucial is establishing the right timing for surgery. PMID:25565876

  2. Axial-Stereo 3-D Optical Metrology for Inner Profile of Pipes Using a Scanning Laser Endoscope

    NASA Astrophysics Data System (ADS)

    Gong, Yuanzheng; Johnston, Richard S.; Melville, C. David; Seibel, Eric J.

    2015-07-01

    As the rapid progress in the development of optoelectronic components and computational power, 3-D optical metrology becomes more and more popular in manufacturing and quality control due to its flexibility and high speed. However, most of the optical metrology methods are limited to external surfaces. This article proposed a new approach to measure tiny internal 3-D surfaces with a scanning fiber endoscope and axial-stereo vision algorithm. A dense, accurate point cloud of internally machined threads was generated to compare with its corresponding X-ray 3-D data as ground truth, and the quantification was analyzed by Iterative Closest Points algorithm.

  3. Axial-Stereo 3-D Optical Metrology for Inner Profile of Pipes Using a Scanning Laser Endoscope

    PubMed Central

    Gong, Yuanzheng; Johnston, Richard S.; Melville, C. David; Seibel, Eric J.

    2015-01-01

    As the rapid progress in the development of optoelectronic components and computational power, 3D optical metrology becomes more and more popular in manufacturing and quality control due to its flexibility and high speed. However, most of the optical metrology methods are limited to external surfaces. This paper proposed a new approach to measure tiny internal 3D surfaces with a scanning fiber endoscope and axial-stereo vision algorithm. A dense, accurate point cloud of internally machined threads was generated to compare with its corresponding X-ray 3D data as ground truth, and the quantification was analyzed by Iterative Closest Points algorithm. PMID:26640425

  4. Extracorporeal Shock Wave Lithotripsy for Management of Residual Stones after Ureterolithotripsy versus Mini-Percutaneous Nephrolithotomy: A Retrospective Study

    PubMed Central

    Huang, Zhichao; Zhao, Xiaokun; Zhang, Lei; Zhong, Zhaohui; Xu, Ran; Zhang, Lianping

    2013-01-01

    Purpose To compare the efficacy of extracorporeal shock wave lithotripsy in managing residual stones after ureterolithotripsy and mini-percutaneous nephrolithotomy. Materials and Methods A retrospective study was carried out of 71 patients with proximal urinary tract stones (greater than 10 mm) who underwent ureterolithotripsy or mini-percutaneous nephrolithotomy at a single institution from 2009 to 2011. The 71 patients were divided into two groups: group I (n = 37) comprised patients who underwent ureterolithotripsy, and group II (n = 34) comprised patients who underwent mini-percutaneous nephrolithotomy. Clinical characteristics, stone-free rates, stone demographics, and complications were evaluated. Results The overall stone-free rate was 90.1%. The stone-free rates in groups I and II were 97.3% and 82.4%, respectively. There was a statistically significant difference in the stone-free rates between groups I and II (P = 0.035). Neither serious intraoperative nor postoperative complications were observed. No significant difference in complications was observed between the two groups (P = 0.472). Conclusions The results of our study suggest that extracorporeal shock wave lithotripsy is an effective and safe auxiliary procedure for managing residual stones after primary endoscopic surgery. This procedure is associated with a satisfactory stone-free rate and a low complication rate, particularly for residual stones after ureteroscopic procedures. PMID:23785516

  5. Endoscopic Sinus Surgery

    MedlinePlus

    ... The nasal endoscope is a small, lighted metal telescope placed into the nostril. The endoscope allows the ... sinus surgery involves the use of a small telescope (nasal endoscope) that is inserted through the nostril ...

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

    PubMed Central

    Zhang, Lin; Zhou, Yiwu

    2015-01-01

    Abstract 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. PMID:26222867

  7. Observation of cavitation during shock wave lithotripsy

    NASA Astrophysics Data System (ADS)

    Bailey, Michael R.; Crum, Lawrence A.; Pishchalnikov, Yuri A.; McAteer, James A.; Pishchalnikova, Irina V.; Evan, Andrew P.; Sapozhnikov, Oleg A.; Cleveland, Robin O.

    2005-04-01

    A system was built to detect cavitation in pig kidney during shock wave lithotripsy (SWL) with a Dornier HM3 lithotripter. Active detection, using echo on B-mode ultrasound, and passive cavitation detection (PCD), using coincident signals on confocal, orthogonal receivers, were equally sensitive and were used to interrogate the renal collecting system (urine) and the kidney parenchyma (tissue). Cavitation was detected in urine immediately upon SW administration in urine or urine plus X-ray contrast agent, but in tissue, cavitation required hundreds of SWs to initiate. Localization of cavitation was confirmed by fluoroscopy, sonography, and by thermally marking the kidney using the PCD receivers as high intensity focused ultrasound sources. Cavitation collapse times in tissue and native urine were about the same but less than in urine after injection of X-ray contrast agent. Cavitation, especially in the urine space, was observed to evolve from a sparse field to a dense field with strong acoustic collapse emissions to a very dense field that no longer produced detectable collapse. The finding that cavitation occurs in kidney tissue is a critical step toward determining the mechanisms of tissue injury in SWL. [Work sup ported by NIH (DK43881, DK55674, FIRCA), ONRIFO, CRDF and NSBRI SMS00203.

  8. Management of lower pole renal calculi: shock wave lithotripsy versus percutaneous nephrolithotomy versus flexible ureteroscopy.

    PubMed

    Preminger, Glenn M

    2006-04-01

    Current ureteroscopic intracorporeal lithotripsy devices and stone retrieval technology allow for the treatment of calculi located throughout the intra-renal collecting system. Difficulty accessing lower pole calculi, especially when the holmium laser fiber is utilized, is often encountered. Herein we review our experience where lower pole renal calculi were ureteroscopically managed by holmium laser fragmentation, either in situ, or by first displacing the stone into a less dependent position with the aid of a nitinol stone retrieval device. Lower pole stones less than 20 mm can be primarily treated by ureteroscopic means in patients: that are obese; have a bleeding diathesis; with stones resistant to shockwave lithotripsy (SWL); with complicated intra-renal anatomy; or as a salvage procedure after failed SWL. Lower pole calculi are fragmented with a 200 microm holmium laser fiber via a 7.5 F flexible ureteroscope. For those patients where the laser fiber reduced ureteroscopic deflection, precluding re-entry into the lower pole calyx, a 1.9 F nitinol basket is used to displace the lower pole calculus into a more favorable position, thus allowing for easier fragmentation. A nitinol device passed into the lower pole, through the ureteroscope, for stone displacement cause only a minimal loss of deflection and no significant impact on irrigation. Eighty-five percent of patients were stone free by IVP or CT scan performed at 3 months. Ureteroscopic management of lower pole calculi is a reasonable alternative to SWL or percutaneous nephrolithotomy (PNL) in patients with low volume stone disease. If the stone cannot be fragmented in situ, nitinol basket or grasper retrieval, through a fully deflected ureteroscope, allows for repositioning of the stone into a less dependant position, thus facilitating stone fragmentation. PMID:16463145

  9. [beta 2-Adrenomimetics before and after extracorporeal lithotripsy].

    PubMed

    Pytel', Iu A; Rapoport, D M; Rudenko, V I; Chaban, A V

    1998-01-01

    Successful disintegration of the calculus in nephrolithiasis patients is impossible without normalization of the upper urinary tracts urodynamics in dyskinesia. We employ combined treatment with high-selective beta-2-adrenomimetic hexoprenalin (hinipral) to improve migration of the concrement fragments and therefore to prevent ureteral occlusion, acute pyelonephritis and renal colic. Hexoprenalin (hinipral) is taken 6 tablets a day or intravenously in drops (5 ml per 100 ml of saline) 3-5 days before and for 10-12 days after extracorporeal shock-wave lithotripsy. Adjuvant use of hexoprenalin in combined treatment of nephrolithiasis complicated by ureteropelvic dysfunction allows effective conduction of lithotripsy. PMID:9820034

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

    PubMed

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

    1991-11-01

    The quality-switched neodymium:yttrium-aluminum-garnet laser represents a new instrument for athermal fragmentation of gallstones by transformation of optical energy into mechanical energy in the form of shock waves via local plasma formation. A highly flexible 300-micron fiber transmission system was used in basic investigations to determine the influence of varying pulse repetition rates (5-30 Hz) and pulse energies (15 and 20 mJ) on shock wave intensity and stone fragmentation in vitro for 105 biliary calculi of known size and chemical composition. After performance of 1200 shock wave pressure measurements using polyvinylidenefluoride hydrophones, stone fragmentation was analyzed by determination of fragment removal rates (volume of fragments removed per fragmentation time), ablation rates (mean volume removed per laser pulse), and median fragment sizes for each laser setting. With the quality-switched neodymium:yttrium-aluminum-garnet laser system, all concrements could be reliably disintegrated into small fragments (median diameter, 0.7-1.7 mm). Compared with pure cholesterol stones, a significantly higher fragment removal rate was achieved in cholesterol stones containing 30% calcium phosphate (P = 0.039), in cholesterol stones containing 20% pigment (P = 0.015), and in pure pigment stones (P = 0.007). Fragment removal rates, local shock wave pressures, and median grain sizes were significantly higher at a pulse energy of 20 mJ than with 15 mJ. Shock wave pressures showed a distinct dependence on pulse repetition rates at 20 mJ, yet not at 15 mJ. Because there is no evident hazard of thermal damage to tissue using the quality-switched neodymium:yttrium-aluminum-garnet laser, it appears to be a promising device for nonsurgical biliary stone therapy. PMID:1682203

  11. Mirizzi Syndrome with Endoscopic Ultrasound Image

    PubMed Central

    Rayapudi, K.; Gholami, P.; Olyaee, M.

    2013-01-01

    We describe a 66-year-old Caucasian man with type 1 Mirizzi syndrome diagnosed on endoscopic ultrasound. He presented with acute onset of jaundice, malaise, dark urine over 3–4 days, and was found to have obstructive jaundice on lab testing. CT scan of the abdomen showed intrahepatic biliary ductal dilation, a 1.5 cm common bile duct (CBD) above the pancreas, and possible stones in the CBD, but no masses. Endoscopic retrograde cholangiopancreatography (ERCP) by a community gastroenterologist failed to cannulate the CBD. At the University Center, type 1 Mirizzi syndrome was noted on endoscopic ultrasound with narrowing of the CBD with extrinsic compression from cystic duct stone. During repeat ERCP, the CBD could be cannulated over the pancreatic duct wire. A mid CBD narrowing, distal CBD stones, proximal CBD and extrahepatic duct dilation were noted, and biliary sphincterotomy was performed. A small stone in the distal CBD was removed with an extraction balloon. The cystic duct stone was moved with the biliary balloon into the CBD, mechanical basket lithotripsy was performed and stone fragments were delivered out with an extraction balloon. The patient was seen 7 weeks later in the clinic. Skin and scleral icterus had cleared up and he is scheduled for an elective cholecystectomy. Mirizzi syndrome refers to biliary obstruction resulting from impacted stone in the cystic duct or neck of the gallbladder and commonly presents with obstructive jaundice. Type 1 does not have cholecystocholedochal fistulas, but they present in types 2, 3 and 4. Surgery is the mainstay of therapy. Endoscopic treatment is effective and can also be used as a temporizing measure or definitive treatment in poor surgical risk candidates. PMID:23741207

  12. Endoscopic photodynamic therapy (PDT) for oesophageal cancer.

    PubMed

    Moghissi, Keyvan

    2006-06-01

    Endoscopic photodynamic therapy (PDT) is undertaken only when tumour is visible endoscopically with malignancy biopsy confirmed. Patients will be either Group A: inoperable cases with locally advanced cancer when the aim is palliation of dysphagia, or Group E: patients with early stage I-II disease who are unsuitable for surgery or decline operation, when the intent is curative. Following assessment for suitability for PDT and counselling, Photofrin 2mg/(kgbw) is administered 24-72h before endoscopic illumination using a Diode 630nm laser. Illumination may be either interstitial or intraluminal at a dose of 100-200J/cm. PMID:25049097

  13. Delivery of Erbium:YAG laser radiation through side-firing germanium oxide optical fibers

    NASA Astrophysics Data System (ADS)

    Ngo, Anthony K.; Fried, Nathaniel M.

    2006-02-01

    The Erbium:YAG laser is currently being tested experimentally for endoscopic applications in urology, including more efficient laser lithotripsy and more precise incision of urethral strictures than the Holmium:YAG laser. While side-firing silica fibers are available for use with the Ho:YAG laser in urology, no such fibers exist for use with the Er:YAG laser. These applications may benefit from the availability of a side-firing, mid-infrared optical fiber capable of delivering the laser radiation at a 90-degree angle to the tissue. The objective of this study is to describe the simple construction and characterization of a side-firing germanium oxide fiber for potential use in endoscopic laser surgery. Side-firing fibers were constructed from 450-micron-core germanium oxide fibers of 1.45-m-length by polishing the distal tip at a 45-degree angle and placing a 1-cm-long protective quartz cap over the fiber tip. Er:YAG laser radiation with a wavelength of 2.94 microns, pulse duration of 300 microseconds, pulse repetition rate of 3 Hz, and pulse energies of from 5 to 550 mJ was coupled into the fibers. The fiber transmission rate and damage threshold measured 48 +/- 4 % and 149 +/- 37 mJ, respectively (n = 6 fibers). By comparison, fiber transmission through normal germanium oxide trunk fibers measured 66 +/- 3 %, with no observed damage (n = 5 fibers). Sufficient pulse energies were transmitted through the side-firing fibers for contact tissue ablation. Although these initial tests are promising, further studies will need to be conducted, focusing on assembly of more flexible, smaller diameter fibers, fiber bending transmission tests, long-term fiber reliability tests, and improvement of the fiber output spatial beam profile.

  14. Endoscopic Microscopy

    PubMed Central

    Sokolov, Konstantin; Sung, Kung-Bin; Collier, Tom; Clark, Anne; Arifler, Dizem; Lacy, Alicia; Descour, Michael; Richards-Kortum, Rebecca

    2002-01-01

    In vivo endoscopic optical microscopy provides a tool to assess tissue architecture and morphology with contrast and resolution similar to that provided by standard histopathology – without need for physical tissue removal. In this article, we focus on optical imaging technologies that have the potential to dramatically improve the detection, prevention, and therapy of epithelial cancers. Epithelial pre-cancers and cancers are associated with a variety of morphologic, architectural, and molecular changes, which currently can be assessed only through invasive, painful biopsy. Optical imaging is ideally suited to detecting cancer-related alterations because it can detect biochemical and morphologic alterations with sub-cellular resolution throughout the entire epithelial thickness. Optical techniques can be implemented non-invasively, in real time, and at low cost to survey the tissue surface at risk. Our manuscript focuses primarily on modalities that currently are the most developed: reflectance confocal microscopy (RCM) and optical coherence tomography (OCT). However, recent advances in fluorescence-based endoscopic microscopy also are reviewed briefly. We discuss the basic principles of these emerging technologies and their current and potential applications in early cancer detection. We also present research activities focused on development of exogenous contrast agents that can enhance the morphological features important for cancer detection and that have the potential to allow vital molecular imaging of cancer-related biomarkers. In conclusion, we discuss future improvements to the technology needed to develop robust clinical devices. PMID:14646041

  15. 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

  16. 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

  17. Damage mechanisms in shock wave lithotripsy (SWL)

    NASA Astrophysics Data System (ADS)

    Lokhandwalla, Murtuza

    Shock wave lithotripsy is a 'non-invasive' therapy for treating kidney stones. Focused shock waves fragment stones to a size that can be passed naturally. There is, however, considerable tissue injury, and the mechanisms of stone fragmentation and tissue injury are not well understood. This work investigates potential tissue damage mechanisms, with an aim towards enhancing stone fragmentation and minimizing tissue damage. Lysis of red blood cells (RBC's) due to in vitro exposure to shock waves was investigated. Fluid flow-fields induced by a non-uniform shock wave, as well as radial expansion/implosion of a bubble was hypothesized to cause cell lysis. Both the above flow-fields constitute an unsteady extensional flow, exerting inertial as well as viscous forces on the RBC membrane. The resultant membrane tension and the membrane areal strain due to the above flow-fields were estimated. Both were found to exert a significantly higher inertial force (50--100 mN/m) than the critical membrane tension (10 mN/m). Bubble-induced flow-field was estimated to last for a longer duration (˜1 microsec) compared to the shock-induced flow (˜1 ns) and hence, was predicted to be lytically more effective, in typical in vitro experimental conditions. However, in vivo conditions severely constrain bubble growth, and cell lysis due to shock-induced shear could be dominant. Hemolysis due to shock-induced shear, in absence of cavitation, was experimentally investigated. The lithotripter-generated shock wave was refocused by a parabolic reflector. This refocused wave-field had a tighter focus (smaller beam-width and a higher amplitude) than the lithotripter wave-field. Cavitation was eliminated by applying overpressure to the fluid. Acoustic emissions due to bubble activity were monitored by a novel passive cavitation detector (HP-PCD). Aluminum foils were also used to differentiate cavitational from non-cavitational mode of damage. RBC's were exposed to the reflected wave-field from

  18. Endoscopic simple prostatectomy

    PubMed Central

    Borkowski, Tomasz; Chłosta, Piotr; Dobruch, Jakub; Fiutowski, Marek; Jaskulski, Jarosław; Słojewski, Marcin; Szydełko, Tomasz; Szymański, Michał; Demkow, Tomasz

    2014-01-01

    Introduction Many options exist for the surgical treatment of lower urinary tract symptoms (LUTS) due to benign prostatic hyperplasia (BPH), including transurethral resection of the prostate (TURP), laser surgery, and open adenomectomy. Recently, endoscopic techniques have been used in the treatment of BPH. Material and methods We reviewed clinical studies in PubMed describing minimally invasive endoscopic procedures for the treatment of BPH. Results Laparoscopic adenomectomy (LA) and robotic–assisted simple prostatectomy (RASP) were introduced in the early 2000s. These operative techniques have been standardized and reproducible, with some individual modifications. Studies analyzing the outcomes of LA and RASP have reported significant improvements in urinary flow and decreases in patient International Prostate Symptom Score (IPSS). These minimally invasive approaches have resulted in a lower rate of complications, shorter hospital stays, smaller scars, faster recoveries, and an earlier return to work. Conclusions Minimally invasive techniques such as LA and RASP for the treatment BPH are safe, efficacious, and allow faster recovery. These procedures have a short learning curve and offer new options for the surgeon treating BPH. PMID:25667758

  19. Experience of curing serious obstruction of advanced-stage upper digestive tract tumor using laser under endoscope

    NASA Astrophysics Data System (ADS)

    Mu, Hai-Bin; Zhang, Man-Ling; Zhang, Xiao-Qiang; Zhang, Feng-Qiu; Kong, De-Jia; Tang, Li-Bin

    1998-11-01

    The patients who suffer from upper digestive tract tumor, such as cancer of esophagus, cancer of cardia, all have serious obstruction and fail to get nutrition and can not bear the strike of the radiotherapy and chemotherapy. In order to reduce the obstruction symptom and suffering of the patients and to prolong their life time, since 1989, our hospital used the laser to cure the upper digestive tract tumor 11 cases with serious obstruction and got remarkable curative effect.

  20. [Endoscopic management of urethral stricture].

    PubMed

    Rossi Neto, R; Tschirdewahn, S; Tschirderwahn, S; Rose, A; vom Dorp, F; Rübben, H

    2010-06-01

    Great progress has been seen in the treatment of urethral strictures since the first endoscopic urethrotomy was performed in 1893 by Felix Martin Oberländer in Dresden, Germany. With the introduction of endoscopic laser therapy and the variety of urethral reconstruction methods other ways to treat this important urologic entity became available. Despite this progress, urethrotomy still represents the preferred treatment concept for primary, short and bulbar urethral strictures. In this study we performed a 2-year retrospective analysis of 20 patients undergoing primary endoscopic urethrotomy by single bulbar or penile narrowing. A high incidence of recurrence was seen in 70% of the patients. Nevertheless, direct vision urethrotomy represented a safe and effective transitory method to treat these patients. Moreover, 80% of the patients preferred, in cases of recurrence, a repeated urethrotomy as the treatment of choice. Although the long-term results evidence high relapse rates after the first and second procedures, there have been no sufficient data in the literature which support the use of other methods. Furthermore, primary endoscopic management of urethral strictures remains a simple, safe, and cost-effective procedure that should be indicated before more invasive approaches are taken to provide relief to these patients from this limiting problem. PMID:20544332

  1. Endoscopic Ultrasound-Guided Needle-Based Probe Confocal Laser Endomicroscopy (nCLE) of Intrapancreatic Ectopic Spleen

    PubMed Central

    Bastidas, Amanda B.; Holloman, David; Lankarani, Ali

    2016-01-01

    Accessory spleens and splenosis represent the congenital and acquired type of ectopic splenic tissue. Generally, they are asymptomatic entities posing as solid hypervascular masses at the splenic hilum or in other organs, such as the pancreas. Intrapancreatic ectopic spleen mimics pancreatic neoplasms on imaging studies, and due to the lack of radiological diagnostic criteria, patients undergo unnecessary distal pancreatectomy. We present the first case of intrapancreatic ectopic spleen in which the concomitant use of needle-based probe confocal laser endomicroscopy and fine-needle aspiration supported the final diagnosis. PMID:27144203

  2. Endoscopic Ultrasound-Guided Needle-Based Probe Confocal Laser Endomicroscopy (nCLE) of Intrapancreatic Ectopic Spleen.

    PubMed

    Bastidas, Amanda B; Holloman, David; Lankarani, Ali; Nieto, Jose M

    2016-04-01

    Accessory spleens and splenosis represent the congenital and acquired type of ectopic splenic tissue. Generally, they are asymptomatic entities posing as solid hypervascular masses at the splenic hilum or in other organs, such as the pancreas. Intrapancreatic ectopic spleen mimics pancreatic neoplasms on imaging studies, and due to the lack of radiological diagnostic criteria, patients undergo unnecessary distal pancreatectomy. We present the first case of intrapancreatic ectopic spleen in which the concomitant use of needle-based probe confocal laser endomicroscopy and fine-needle aspiration supported the final diagnosis. PMID:27144203

  3. Nonvisualized gallbladder on oral cholecystography: implications for lithotripsy.

    PubMed

    Wong, K; Ekberg, O; Laufer, I; Malet, P F; Arger, P

    1990-01-01

    Currently, most protocols evaluating the efficacy of gallstone lithotripsy require a visualized gallbladder on oral cholecystography (OCG). The primary purpose of the OCG is to establish that the cystic duct is patent. When the gallbladder is visualized on OCG, it can also be used to number and size gallstones accurately. Patients with non-visualization of the gallbladder on OCG are excluded from consideration for lithotripsy. The purpose of this study was to evaluate retrospectively the ultrasonographic findings (i.e., number and sizes of stones in 32 patients with nonvisualization on the OCG). In 11 patients (34%) ultrasound (US) did not detect any stone, and it is presumed that the gallbladder failed to visualize for other reasons. Six patients (19%) had one or two stones and 15 (47%) patients had more than three stones. This suggests that 20% of patients with nonvisualization of the gallbladder on OCG would otherwise be eligible for lithotripsy provided that patency of the cystic duct can be demonstrated by other means, such as computed tomographic (CT) examination with oral biliary contrast or cholescintigraphy. PMID:2180774

  4. 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

  5. Percutaneous papillary large balloon dilation during percutaneous cholangioscopic lithotripsy for the treatment of large bile-duct stones: a feasibility study.

    PubMed

    Han, Jee Young; Jeong, Seok; Lee, Don Haeng

    2015-03-01

    When access to a major duodenal papilla or endoscopic retrograde cholangiopancreatography has failed, percutaneous transhepatic cholangioscopic lithotripsy (PTCS-L) may be useful for removing common bile duct (CBD) stones. However, the feasibility and usefulness of percutaneous transhepatic papillary large-balloon dilation (PPLBD) during PTCS-L for the removal of large CBD stones has not been established. We aimed to determine the safety and efficacy of PPLBD for the treatment of large CBD stones. Eleven patients with large CBD stones in whom the access to the major papilla or bile duct had failed were enrolled prospectively. Papillary dilation was performed using a large (12-20 mm) dilation balloon catheter via the percutaneous transhepatic route. Post-procedure adverse events and efficacy of the stone retrieval were measured. The initial success rate of PPLBD was 100%. No patient required a basket to remove a stone after PPLBD. Electrohydraulic lithotripsy was required in 2 (18.2%) patients. The median time to complete stone removal after PPLBD was 17.8 min and no adverse events occurred after PPLBD. Asymptomatic hyperamylasemia was not encountered in any patients. This study indicates that PPLBD is safe and effective for removal of large CBD stones. PMID:25729250

  6. Technological fundamentals of endoscopic haemostasis.

    PubMed

    Reidenbach, H D

    1992-01-01

    In order to perform endoscopic haemostasis there exist several different mechanical, biochemical and thermal methods, which may be applied together with rigid or fully flexible endoscopes in different situations. The technological fundamentals of convective, conductive and radiative heat transfer, the irradiation with coherent electromagnetic waves like microwaves and laser radiation and the resistive heating by RF-current are described. A review of the state of the art of haemostatic coagulation by laser radiation (photocoagulation) and radio-frequency currents (surgical diathermy, high-frequency coagulation) is given. The wavelength-dependent interactions of coherent light waves are compared especially for the three mainly different laser types, i.e., carbon-dioxide-, neodymium-YAG- and argon-ion-laser. The well-known disadvantages of the conventional RF-coagulation are overcome by the so-called electrohydrothermosation (EHT), i.e. the liquid-assisted application of resistive heating of biological tissues to perform haemostasis. Different technological solutions for bipolar RF-coagulation probes including ball-tips and forceps are shown and the first experimental results are discussed in comparison. PMID:1595405

  7. FRAGMENTATION OF URINARY CALCULI IN VITRO BY BURST WAVE LITHOTRIPSY

    PubMed Central

    Maxwell, Adam D.; Cunitz, Bryan W.; Kreider, Wayne; Sapozhnikov, Oleg A.; Hsi, Ryan S.; Harper, Jonathan D.; Bailey, Michael R.; Sorensen, Mathew D.

    2015-01-01

    Purpose We have developed a new method of lithotripsy that uses short, broadly focused bursts of ultrasound rather than shock waves to fragment stones. This study investigated the characteristics of stone comminution by burst wave lithotripsy in vitro. Materials and Methods Artificial and natural stones (mean 8.2±3.0 mm, range 5–15 mm) were treated with ultrasound bursts using a focused transducer in a water bath. Stones were exposed to bursts with focal pressure amplitude ≤6.5 MPa at 200 Hz burst repetition rate until completely fragmented. Ultrasound frequencies of 170 kHz, 285 kHz, and 800 kHz were applied using 3 different transducers. The time to achieve fragmentation for each stone type was recorded, and fragment size distribution was measured by sieving. Results Stones exposed to ultrasound bursts were fragmented at focal pressure amplitudes ≥2.8 MPa at 170 kHz. Fractures appeared along the stone surface, resulting in fragments separating at the surface nearest to the transducer until the stone was disintegrated. All natural and artificial stones were fragmented at the highest focal pressure of 6.5 MPa with treatment durations between a mean of 36 seconds for uric acid to 14.7 minutes for cystine stones. At a frequency of 170 kHz, the largest artificial stone fragments were <4 mm. Exposures at 285 kHz produced only fragments <2 mm, and 800 kHz produced only fragments <1 mm. Conclusions Stone comminution with burst wave lithotripsy is feasible as a potential noninvasive treatment method for nephrolithiasis. Adjusting the fundamental ultrasound frequency allows control of stone fragment size. PMID:25111910

  8. 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

  9. 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.

  10. [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. PMID:1364639

  11. Endoscopic Evaluation of Swallowing (Endoscopy)

    MedlinePlus

    ... the Public / Speech, Language and Swallowing / Swallowing Endoscopic Evaluation of Swallowing (Endoscopy) Do you have problems swallowing? ... Some names you might hear are: Endoscopy Endoscopic Evaluation of swallowing FEES (Fiberoptic Endoscopic Evaluation of Swallowing) ...

  12. [Extracorporeal lithotripsy in the treatment of renal colic].

    PubMed

    Derevianko, I M; Naumenko, A A

    1996-01-01

    Renal colic arises in acute ureteral obstruction and indicates a sharp rise in intrapelvic pressure (up to 150 mm Hg). The diagnosis of renal colic is made basing on direct and indirect measurements of intrapelvic pressure. Ultrasound in renal colic detects dilatation of the calices and pelvis on the colic side, ureterolith can be also revealed by ultrasound. The authors used extracorporeal lithotripsy for fragmentation of the stone and colic relief in 68 patients. The colic stopped in all the cases. This method is extremely valuable in cases when spasmolytic and analgetic drugs, other conservative modalities fail. PMID:8928326

  13. Renal milk of calcium: contraindication to extracorporeal shockwave lithotripsy.

    PubMed

    Heidenreich, A; Vorreuther, R; Krug, B; Moul, J W; Engelmann, U H

    1996-01-01

    Renal milk-of-calcium (MOC) cysts are rare findings, with only approximately 60 cases reported in the literature. The diagnosis depends on the demonstration of the typical "half-moon" configuration on horizontal beam radiography; classical ultrasound finding is a gravity-dependent, echogenic shadowy material in a renal cyst. The importance of the MOC syndrome lies in its recognition and differentiation from a renal stone in order to avoid unwarranted surgery or extracorporeal shock-wave lithotripsy (ESWL). We have encountered five patients with renal MOC and present the typical clinical and radiological features in order to facilitate differential diagnosis. PMID:9118405

  14. [Endoscopic treatment of urethral strictures].

    PubMed

    Oosterlinck, W; Lumen, N

    2006-08-01

    The present article reviews the literature regarding the endoscopic treatment of urethral strictures. Only few prospective randomised clinical trials with sufficient power have been performed and most of the literature provides evidence of only level 3 and 4. Since length, location, extent and calibre of the urethral stricture have an important impact on prognosis, diagnosis and the role of ultrasonography are discussed. Pathophysiology of wound healing is discussed in relation to urethrotomy, as it explains the outcomes of the procedure. Operative techniques using cold knife and laser, use of endoprostheses, indications, complications, results and postoperative management are described. The possible role of urethral catheters, hydraulic dilatations and corticosteroid applications are discussed. PMID:16970069

  15. Endoscopic palliation of tracheobronchial malignancies.

    PubMed Central

    Hetzel, M R; Smith, S G

    1991-01-01

    The prognosis for tracheobronchial tumours remains poor. Most patients can be offered only palliation. When the main symptom is breathlessness or refractory haemoptysis from a large airway tumour endoscopic treatment may be very effective. Over the last decade most attention has focused on the neodymium YAG laser. This often produces dramatic effects but has some important limitations. In the last few years better techniques for stenting and intrabronchial radiotherapy (brachytherapy) have also been developed. This article discusses the range of techniques now available and aims to help clinicians decide which patients may benefit from referral to centres providing these techniques. Images PMID:1712516

  16. Transurethral laser urethrotomy in man: preliminary report.

    PubMed

    Bülow, H; Bülow, U; Frohmüller, H G

    1979-03-01

    After in vitro and in vivo endoscopic laser investigation on normal and experimentally strictured urethras in dogs transurethral laser urethrotomy was done on men. A neodymium: yttrium aluminum garnet laser with a flexible laser light guide was used. The endoscope developed for this purpose is described in detail. The first laser operations were without complications. PMID:430619

  17. 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.

  18. 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

  19. 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.

  20. Modification of the edge wave in shock wave lithotripsy

    NASA Astrophysics Data System (ADS)

    Zhou, Yufeng

    2012-10-01

    To reduce the bubble cavitation and the consequent vascular injury of shock wave lithotripsy (SWL), a new method was devised to modify the diffraction wave generated at the aperture of a Dornier HM-3 lithotripter. Subsequently, the duration of the tensile wave was shortened significantly (3.2±0.54 μs vs. 5.83±0.56 μs). However, the amplitude and duration of the compressive wave of LSW between these two groups as well as the -6 dB beam width and the amplitude of the tensile wave are almost unchanged. The suppression on bubble cavitation was confirmed using the passive cavitation technique. At the lithotripter focus, while 30 shocks can cause rupture of blood vessel phantom using the HM-3 lithotripter at 20 kV; no rupture could be found after 300 shocks with the edge extender. On the other hand, after 200 shocks the HM-3 lithotripter at 20 kV can achieve a stone fragmentation of 50.4±2.0% on plaster-of-Paris stone phantom, which is comparable to that of using the edge extender (46.8±4.1%, p=0.005). Altogether, the modification on the diffraction wave at the lithotripter aperture can significantly reduce the bubble cavitation activities. As a result, potential for vessel rupture in shock wave lithotripsy is expected.

  1. Development of 3D holographic endoscope

    NASA Astrophysics Data System (ADS)

    Özcan, Meriç; Önal Tayyar, Duygu

    2016-03-01

    Here we present the development of a 3D holographic endoscope with an interferometer built around a commercial rigid endoscope. We consider recording the holograms with coherent and incoherent light separately without compromising the white light imaging capacity of the endoscope. In coherent light based recording, reference wave required for the hologram is obtained in two different ways. First, as in the classical holography, splitting the laser beam before the object illumination, and secondly creating the reference beam from the object beam itself. This second method does not require path-length matching between the object wave and the reference wave, and it allows the usage of short coherence length light sources. For incoherent light based holographic recordings various interferometric configurations are considered. Experimental results on both illumination conditions are presented.

  2. Endoscopic video manifolds for targeted optical biopsy.

    PubMed

    Atasoy, Selen; Mateus, Diana; Meining, Alexander; Yang, Guang-Zhong; Navab, Nassir

    2012-03-01

    Gastro-intestinal (GI) endoscopy is a widely used clinical procedure for screening and surveillance of digestive tract diseases ranging from Barrett's Oesophagus to oesophageal cancer. Current surveillance protocol consists of periodic endoscopic examinations performed in 3-4 month intervals including expert's visual assessment and biopsies taken from suspicious tissue regions. Recent development of a new imaging technology, called probe-based confocal laser endomicroscopy (pCLE), enabled the acquisition of in vivo optical biopsies without removing any tissue sample. Besides its several advantages, i.e., noninvasiveness, real-time and in vivo feedback, optical biopsies involve a new challenge for the endoscopic expert. Due to their noninvasive nature, optical biopsies do not leave any scar on the tissue and therefore recognition of the previous optical biopsy sites in surveillance endoscopy becomes very challenging. In this work, we introduce a clustering and classification framework to facilitate retargeting previous optical biopsy sites in surveillance upper GI-endoscopies. A new representation of endoscopic videos based on manifold learning, "endoscopic video manifolds" (EVMs), is proposed. The low dimensional EVM representation is adapted to facilitate two different clustering tasks; i.e., clustering of informative frames and patient specific endoscopic segments, only by changing the similarity measure. Each step of the proposed framework is validated on three in vivo patient datasets containing 1834, 3445, and 1546 frames, corresponding to endoscopic videos of 73.36, 137.80, and 61.84 s, respectively. Improvements achieved by the introduced EVM representation are demonstrated by quantitative analysis in comparison to the original image representation and principal component analysis. Final experiments evaluating the complete framework demonstrate the feasibility of the proposed method as a promising step for assisting the endoscopic expert in retargeting the

  3. 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.

  4. 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. PMID:27115879

  5. 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

  6. 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. PMID:8481720

  7. Abdominal Compartment Syndrome and Necrotizing Pancreatitis Following Extracorporeal Shock Wave Lithotripsy.

    PubMed

    Gupta, S; Scambia, J; Gandillon, C; Aversano, F; Batista, R

    2016-09-01

    Extracorporeal shock wave lithotripsy (ESWL) is a common procedure in the treatment of renal calculi. There have been major complications reported with ESWL such as acute pancreatitis, bower perforation, venous thrombosis, and biliary obstruction. There are few reports in the literature of necrotizing pancreatitis secondary to ESWL. We have a case report of a 29-year-old female that developed an abdominal compartment syndrome with an acute necrotizing pancreatitis hours after extracorporeal shock wave lithotripsy. PMID:27462545

  8. Current applications of endoscopic suturing

    PubMed Central

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

    2015-01-01

    Endoscopic suturing had previously been considered an experimental procedure only performed in a few centers and often by surgeons. Now, however, endoscopic suturing has evolved sufficiently to be easily implemented during procedures and is more commonly used by gastroenterologists. We have employed the Apollo OverStitch suturing device in a variety of ways including closure of perforations, closure of full thickness defects in the gastrointestinal wall created during endoscopic full thickness resection, closure of mucosotomies during peroral endoscopic myotomy, stent fixation, fistula closure, post endoscopic submucosal dissection, endoscopic mucosal resection and Natural Orifice Transluminal Endoscopic Surgery defect closures, post-bariatric surgery gastrojejunal anastomosis revision and primary sleeve gastroplasty. PMID:26191342

  9. Pneumatic v electrokinetic lithotripsy in treatment of ureteral stones.

    PubMed

    Vorreuther, R; Klotz, T; Heidenreich, A; Nayal, W; Engelmann, U

    1998-06-01

    Recently, a new device (Combilith) for electrokinetic lithotripsy (EKL) has become available which is very similar to the well-known device for pneumatic (ballistic) lithotripsy (Swiss Lithoclast). The Lithoclast uses air pressure to push a projectile within the handpiece against the end of a metal probe, which is thereby accelerated and thrown like a jackhammer against the stone. In principle, the same stroking movement of a small metal probe is provided by EKL; the difference is that instead of a projectile, a magnetic core within the handpiece is accelerated by the electromagnetic principle. This paper compares the clinical efficacy and the features of the two devices. Testing the devices on a stone model, taking into account stone propulsion, the systems turned out to equally effective regarding stone disintegration. However, stone displacement was more pronounced with the Lithoclast applied on easily breaking stones. In a second experiment, an optoelectronic movement-measuring apparatus (Zimmer camera) was employed to measure the range and velocity of the movement of the probe tip without any contact. The linear acceleration velocity ranged from 5 to a maximum of 12.5 m/sec with both systems, but the maximum height of the stroke was 2.5 mm with the Lithoclast and 1 mm with EKL. After the initial break-up of soft stones, further impact of the probe tip against the stone resulted merely in propulsion; thus, the greater probe stroke height is the cause of the stone displacement. In a clinical trial, 22 ureteral stones were treated with the Lithoclast and 35 with the EKL. The two devices were equally effective in terms of stone disintegration and safety margin. Fixation using a Dormia basket was necessary in 12 cases (8 Lithoclast, 4 EKL). Although a difference in probe stroke height was noted when comparing pneumatic and electrokinetic lithotripsy, there were no clinically significant differences in the efficacy of stone fragmentation or stone-free rates. At the

  10. 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