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PubMed1986

Laser lithotripsy of gallstone by means of a pulsed neodymium-YAG laser--in vitro and animal experiments.

Using a flashlamp pulsed Nd: YAG laser it is possible to destroy gallstones within a few seconds (median: 4 sec for stones less than 1.5 cc; 9.5 sec greater than 1.5 cc). In in vitro and animal studies it was shown that the median energy needed for stone destruction varies between 32 Joule for stones less than 1.5 cc and 80 Joules for stones greater than 1.5 cc. A 0.2 mm thick, flexible glass fibre makes possible retrograde laser lithotripsy by conventional endoscopes. Using a suitable technique the danger of thermal damage to tissue is small.

Animals↗

PubMed2004

Ureteroscopic holmium: YAG laser lithotripsy for managing ureteral calculi (a report of 168 cases).

The effectiveness and safety of ureteroscopic holmium: YAG laser lithotripsy for managing ureteral calculi was evaluated. Ureteroscopic holmium. YAG laser lithotripsy was performed in 168 ureteral calculi (upper 27 cases, middle 33 cases and lower 108 cases). The results showed that the stone-free rate was 92.6% in the upper ureteral calculi, 93.9% in the middle ureteral calculi and 94.4% in the lower ureteral calculi, respectively. The complication rate was 4.8% (8 cases). It was suggested that ureteroscopic holmium: YAG laser lithotripsy is a highly effective and safe treatment modality for managing ureteral calculi.

Adult↗

PubMedDate not supplied

[Endoscopic laser lithotripsy for difficult calculi after unsuccessful extracorporeal shock wave lithotripsy].

INTRODUCTION: More than 97% of common bile duct stones can be successfully managed by endoscopic papillotomy, mechanical lithotripsy and extracorporeal shock-wave lithotripsy. In this study, we evaluate the role of laser lithotripsy after failure of the above mentioned endoscopic methods. PATIENTS AND METHODS: Eighteen patients (15F, 3M; median age = 69 (28-83) years) were treated by endoscopic laser lithotripsy after ESWL failure. We employed a Rhodamine-6 G laser with a stone-tissue recognizing system. The laser fibers were cholangioscopically (direct vision) or blindly (under plain fluoroscopic control) placed. RESULTS: Seventeen patients were treated endoscopically and one was successfully managed percutaneously after failure of the transpapillary approach. Fourteen (78%) were stone-free after a mean of 1.56 laser therapy sessions alone. Two additional patients were successfully managed after partial fragmentation with combined treatment (mechanical lithotripsy: n = 1, electrohydraulic lithotripsy: n = 1). Overall, 89% of the patients were freed from their calculi. Cholangitis occurred once and the mortality was zero. CONCLUSIONS: We conclude that laser lithotripsy is an effective and safe treatment alternative in a highly selected patient population with difficult bile duct stones and considerable surgical risk.

Adult↗

PubMed2005

Therapeutic options for proximal ureter stone: extracorporeal shock wave lithotripsy versus semirigid ureterorenoscope with holmium:yttrium-aluminum-garnet laser lithotripsy.

OBJECTIVES: To compare the safety and cost-effectiveness of ureterorenoscopic holmium:yttrium-aluminum-garnet (YAG) laser lithotripsy (URSL) with extracorporeal shock wave lithotripsy (ESWL) for proximal ureteral stones. METHODS: This investigation assessed 220 patients with upper ureteral stones. Those in the ESWL group were treated on an outpatient basis using the Medispec Econolith 2000 (Medispec, Germantown, MD) under intravenous sedation. URSL was performed with a 6/7.5F semirigid tapered ureterorenoscope and holmium:YAG laser under spinal anesthesia on an inpatient basis. A successful outcome was defined as the patient being stone free on radiography 1 month after treatment. The stone size, success rate, postoperative complications, and cost were evaluated in each group. RESULTS: A total of 220 patients were enrolled in this study. Hematuria and flank pain were the most common complaints in each group. The mean stone burden +/- SD was 58.7 +/- 3.1 mm2 in the ESWL group and 108.4 +/- 10.0 mm2 in the URSL group (P = 0.000). The accessibility of the semirigid ureterorenoscope for upper ureteral stones was 98.1% (101 of 103), and the stone-free rate achieved after one treatment was 83.2% (84 of 101). The initial stone-free rate of in situ ESWL was 63.9% (76 of 119). Significantly, the initial stone-free rate of the URSL group was superior to that of the ESWL group (P = 0.001). The average cost in the URSL group appeared to be lower than that in the ESWL group (P = 0.000). CONCLUSIONS: The results of this study have demonstrated that URSL achieved excellent results for upper ureter calculi. In terms of cost and effectiveness, this procedure should be the first-line therapy for proximal ureter stones.

Costs and Cost Analysis↗

PubMed2003

A prospective randomized controlled trial on ureteral stenting after ureteroscopic holmium laser lithotripsy.

PURPOSE: A prospective randomized controlled trial was conducted to evaluate whether postoperative ureteral stenting is necessary after ureteroscopic laser lithotripsy. MATERIALS AND METHODS: A total of 58 patients with unilateral ureteral stones were randomized into either stented or unstented groups. Ureteroscopic laser lithotripsy was performed using a semirigid ureteroscope (6.5/7Fr) and holmium laser without ureteral orifice dilation. There were no selection criteria regarding stone size, location, preoperative ureteral obstruction and hydronephrosis. Endoscopic evidence of stone impaction or mucosal edema/damage did not exclude a patient from the study. Ureteral perforation on completion retrograde pyelogram was the only intraoperative criterion for study exclusion. Postoperative pain scores and symptoms were recorded. Excretory urography was performed to document stone-free status and stricture formation. Radionuclide scan was performed selectively to exclude functional obstruction when ureteral narrowing was found on excretory urogram. RESULTS: Mean stone size +/- SD was 9.7 +/- 4.0 mm. (range 4 to 27). Proximal ureteral stones accounted for 43% of all stones. Stented and unstented groups were comparable with respect to demographic data, stone parameters, preoperative obstruction and hydronephrosis. There was no significant difference in operating time, laser energy used, stone impaction and mucosal edema/damage between the 2 groups. Postoperative pain and symptoms were more severe and frequent (p <0.05) in the stented group. However, there was no difference in the incidence of postoperative sepsis and unplanned medical visits. The stone-free and stricture formation rates showed no statistical difference between the 2 groups. CONCLUSIONS: Ureteral stenting is not necessary after uncomplicated ureteroscopic laser lithotripsy for ureteral stones. Ureteral stent increases the incidence of pain and urinary symptoms but does not prevent postoperative urinary sepsis and unplanned medical visits. Severity of preoperative obstruction and intraoperative ureteral trauma were not shown to be determining factors for stenting.

Adult↗

PubMed1992

[Laser lithotripsy in the treatment of ureteral lithiasis].

Laser lithotripsy constitutes a safe method with a success rate of 95% in the treatment of ureteral calculi. The photoacoustic properties of the laser permit stone fragmentation without injury to tissue. The major disadvantage of this technique is its cost. The availability of increasingly smaller electrohydraulic systems that are less costly questions the routine use of the laser system. Another aspect that must be considered is the rapid development of endourologic techniques and instruments in recent years. The use of laser-induced shock waves is not exclusive to the field of Urology. In other surgical specialties where electrohydraulic energy is difficult to use, it constitutes a necessary technique. Such is the case of endoscopy of the bile ducts, fragmentation of pancreatic calculi and lithiasis of the salivary glands. Another possible field of application of laser-induced shock waves is coronary angioplasty.

Humans↗

PubMed2001

Long-term effects of ureteroscopic laser lithotripsy on glomerular filtration rate in the face of mild to moderate renal insufficiency.

BACKGROUND AND PURPOSE: Ureteroscopic laser treatment of calculi in the upper urinary tract was examined in regard to its effect on renal function in the setting of mild renal insufficiency. Percutaneous nephrolithotomy (PCNL) and SWL have been previously shown not to adversely affect the glomerular filtration rate (GFR) in renal insufficiency, but to our knowledge, the effect of ureteroscopic laser lithotripsy on GFR has not been previously reported. PATIENTS AND METHODS: A retrospective review of all cases of ureteroscopic laser lithotripsy at our institution was performed. A total of 18 patients with a baseline serum creatinine of > or = 1.5 mg/dL were found. The mean follow-up after treatment was 18.0 months (range 4-39 months). The change in the reciprocal of serum creatinine was used as an indicator of change in the GFR. Deterioration of 20% was considered significant. RESULTS: The overall mean change in treated patients was a 5.9% improvement. Patients with a preoperative creatinine of < 2.0 mg/dL improved 7.6% and those with creatinine of > or = 2.0 mg/dL increased 3.9%. Other factors such as the size of the stone, location of the stone, and total joules used during treatment were not significant. CONCLUSION: This examination suggests that ureteroscopic laser lithotripsy has no ill effects on renal function in the face of mild to moderate renal insufficiency.

Adult↗

PubMed1991

High energy pulsed dye laser lithotripsy: management of ureteral calcium oxalate monohydrate calculi.

High energy pulsed dye laser lithotripsy (Candela MDL-2000), with energy output upgraded to a maximum of 140 mJ. at the laser fiber tip using the 320 mu core fiber, was compared to the initially commercialized device, with the energy output fixed at 60 mJ. using the 200 mu core fiber (Candela MDL-1). A total of 31 treatments in 28 patients was performed with the Candela MDL-1 device. Complete disintegration or at least fragmentation to spontaneously passable fragments occurred in 18 of 31 cases (58%). Only in 11 of the 24 calcium oxalate monohydrate calculi (46%) was fragmentation achieved. Another 73 laser lithotripsies in 72 patients were performed with the Candela MDL-2000 device. Complete disintegration or at least fragmentation to spontaneously passable fragments was achieved in 67 of 73 treatments (92%). Calcium oxalate monohydrate calculi were successfully treated in 41 of 45 procedures (91%). There was no response to the laser treatment in the only cystine calculus.

Adolescent↗

PubMed1989

Effect of pulse duration on microsecond-domain laser lithotripsy.

The pulsed dye laser (wavelength 504 nm, pulse duration 1 microsecond) is widely used for fragmenting urinary and biliary calculi. In this study, the performance of this laser was compared with pulsed dye lasers producing pulse durations of 8 and 20 microseconds. Fragmentation thresholds and fragmentation rates were measured using a variety of urinary and biliary calculi. Effective fragmentation of urinary and biliary calculi was obtained with 1-microsecond and 8-microseconds pulse durations, but satisfactory fragmentation could not be achieved at 20 microseconds.

Cholelithiasis↗

PubMed1991

Clinical experience with high power (140 mj.), large fiber (320 micron) pulsed dye laser lithotripsy.

The pulsed dye laser, at 504 nm. wavelength with a pulse duration of 1 microsecond, was used at 140 mj. per pulse via a 320 mu. (core) fiber for fragmentation of 72 ureteral calculi. The fragmentation efficiency and clinical results using the 140 mj./320 mu. fiber were compared to previous experience using the 60 mj./200 mu. (core) fiber. Fragmentation efficiency was significantly improved requiring many fewer laser pulses to fragment calculi of similar size and composition, and decreasing the need for auxiliary methods to complete stone fragmentation. The higher energy and larger fiber allowed for more efficient ureteroscopic ureteral stone fragmentation without compromising tissue safety.

Endoscopes↗

PubMed2000

Use of a working channel catheter during flexible ureteroscopic laser lithotripsy.

PURPOSE: We describe a technique which protects the working channel of the flexible ureteroscope from damage caused by the laser fiber during laser lithotripsy. MATERIALS AND METHODS: A 2Fr catheter is placed into the working channel of the flexible ureteroscope. A 200 micro. laser fiber is then advanced through the lumen of the catheter and laser lithotripsy is subsequently performed. RESULTS: The catheter provides additional protection to the working channel sheath during passage and firing of the laser fiber. Deflection of the ureteroscope is not affected with the catheter in place. Movement of the laser fiber is augmented by the catheter when compared to movement of the fiber in the working channel alone. Irrigant flow is diminished with the catheter. CONCLUSIONS: The catheter does not appear to hinder performance of the flexible ureteroscope during laser lithotripsy. A catheter also offers additional protection to the working channel sheath, thereby potentially increasing the durability and working life of the flexible ureteroscope.

Humans↗

PubMed2001

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

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.

Animals↗

PubMed1991

Pulsed dye laser lithotripsy of bile duct stones.

Efficacy and safety of pulsed dye laser lithotripsy was tested in 25 consecutive patients in whom bile duct stones could not be extracted after endoscopic sphincterotomy. The patients had one to six (mean, 1.8) bile duct stones (diameter, 10-35 mm; mean, 18 mm) located in the common bile duct (18 cases), the intrahepatic bile ducts (6 cases), or in a long cystic duct stump (1 case). Different approaches were tested depending on the presence of a T tube and on the localization of the bile duct stones. When a T tube was present (7 cases), the lithotripsy was performed under direct vision using a choledochoscope inserted through the T-tube tract. In 18 patients without a T tube in place, the lithotripsy was performed under fluoroscopy using a retrograde approach in case of common bile duct stones (14 cases) or under choledochoscopy using a percutaneous transhepatic approach in case of intrahepatic bile duct stones (4 cases). Fragmentation of all the bile duct stones and a complete bile duct clearance were obtained in all 11 cases with procedures performed under direct vision as compared with only 5 of 14 cases with procedures under fluoroscopic control. Moreover, 6 of the 9 failures using the latter approach were offered another session using a choledochoscope inserted through a percutaneous transhepatic tract and were also successfully treated. No complication related to the laser beam was noted. It is concluded that pulsed dye laser lithotripsy of bile duct stones (that are unable to be removed by standard endoscopic techniques) is safe and efficacious provided that it is performed under direct vision. Technical refinements are needed before this procedure can be reliably performed under fluoroscopy.

Aged↗

PubMed1993

Photosensitization of cystine stones to induce laser lithotripsy.

We report the preliminary results of laser lithotripsy of cystine stones accomplished in 2 patients with the use of a new method of photosensitization. Transurethral rigid ureterorenoscopy was performed with an 8.5F instrument to reach 0.8 and 1.8 cm. stones located in the right and left lumbar ureters, respectively. A 320 mu. fiber was then inserted and pushed into contact with the stone. Then, 400 preliminary impulses were released from a pulsed dye laser (504 nm) with energy output at 140 mJ. and at a rate of 5 Hz. without any visible modification of the stone structure. The saline solution used as irrigation fluid was then substituted with a 2% solution of rifamycin. Totals of 95 and 152 impulses released at the same energy output previously used were then sufficient to produce a satisfactory fragmentation of the stone in both cases. Sonography and excretory urography showed no alterations of the treated urinary tract in either case. The use of rifamycin in the irrigation fluid is suggested for laser treatment of hard or nonabsorbent stones, since this substance favors optical coupling and lowers the threshold of plasma formation on the surface of the stone.

Adolescent↗

PubMed2006

[Holmium: YAG laser lithotripsy under ureteroscopy for treating urinary caluli combined with acute renal failure].

OBJECTIVE: To evaluate the therapeutic effect and safety of holmium:YAG laser lithotripsy for treating ureteral calculi combined with acute renal failure. METHODS: Ureteroscopic holmium: YAG laser lithotripsy was used in 13 cases of ureteral calculi. RESULTS: After the operation the serum Bun and Cr levels in the patients decreased to different degrees or returned to normal and the stone free rate was up to 92.3% (12/13). CONCLUSION: The ureteroscopic holmium:YAG laser lithotripsy can be the first choice for the upper urinary tract obstruction associated with acute renal failure,due to its safety and efficiency. It can also deal with the double sites of ureteral diseases.

Acute Kidney Injury↗

PubMed2002

Holmium:YAG laser lithotripsy for upper urinary tract calculi in 598 patients.

PURPOSE: We assessed the effectiveness and safety of holmium:YAG laser lithotripsy for managing upper urinary tract calculi in a prospective cohort of 598 patients. MATERIALS AND METHODS: Ureteroscopic holmium:YAG laser lithotripsy was performed in 598 patients between 1993 and 1999. Calculi were located in the distal ureter in 39.6% of cases, mid ureter in 18.6%, proximal ureter in 32.4% and kidney in 9.4%. Patients were treated on an outpatient basis with various flexible and semirigid endoscopes. Of the cases 59% were referred as previous treatment failures. Patients were assessed 6 to 12 weeks postoperatively with repeat plain x-ray and ultrasound or excretory urography for late obstructive complications. RESULTS: The overall stone-free rate was 97%. As stratified by location, the stone-free rate was 98% in the distal ureter, 100% in the mid ureter, 97% in the proximal ureter and 84% in the kidney. Fragmentation was incomplete in 6% of cases and secondary intervention was required in 6%. The overall complication rate was 4%. New onset ureteral stricture developed postoperatively in 0.35% of patients. CONCLUSIONS: Holmium:YAG laser lithotripsy is a highly effective and safe treatment modality for managing ureteral and a proportion of intrarenal calculi on an outpatient basis. The effectiveness and versatility of the holmium laser combined with small rigid or flexible endoscopes make it our modality of choice for ureteroscopic lithotripsy.

Adolescent↗

PubMed1990

[Laser lithotripsy with automatic shut-off on tissue contact].

A group of 88 patients with 89 ureteral calculi were treated with the pulsed dye-laser. Visual control was carried out through 8.5-F or 9.5-F ureteroscopes. The laser has automatic shut-off via spectrum analysis of back-scatter laser light. Effective laser pulses can therefore only be induced in the case of contact with the stone. Of the 89 stones 58 (65.2%) were completely fragmented by laser lithotripsy, 15 (16.8%) by laser lithotripsy in combination with ESWL and 9 (10.1%) by other ureteroscopic techniques. Ureterolithotomy was necessary only in 1 case (1%). There were 5 calculi (5.6%) that were too hard for fragmentation. The pulsed dye-laser is a safe and effective treatment modality for ureteral calculi that are not accessible for ESWL or in which ESWL has been unsuccessful. Further experimental and clinical trials will have to show whether miniature probes for electrohydraulic lithotripsy, dye-laser with automatic shut-off, or alexandrite laser will be the method of choice for lithotripsy of ureteral calculi.

Endoscopes↗

PubMed2006

Risk factors for symptomatic stone recurrence after transpapillary laser lithotripsy for difficult bile duct stones using a laser with a stone recognition system.

BACKGROUND: Laser-induced shock-wave lithotripsy (LISL) is successfully used for the treatment of difficult bile duct stones. The aim of this study was to assess the long-term risk for a symptomatic bile duct stone recurrence after LISL and to detect risk factors predicting recurrence. METHODS: Between 1993 and 2001, 80 patients with difficult bile duct stones were successfully treated by intracorporeal LISL through the papilla of Vater. Seventy-one of these patients [median age, 65.8 years; 51 women (71.8%)] were followed for a median (range) period of 58 (1-114) months. RESULTS: Eleven patients (15.5%) had a symptomatic stone recurrence. The median (range) period between laser lithotripsy and recurrence was 40 (5-85) months. The presence of a bile duct stenosis (P=0.032) and a body-mass index below 25 (P=0.025) were significantly associated with an increased risk for stone recurrence. A gallbladder in situ, the presence of gallbladder stones, dilation of the bile duct, or a peripapillary diverticulum was not associated with stone recurrence. CONCLUSIONS: The presence of a bile duct stenosis is significantly related to bile duct stone recurrence after treatment with LISL. The impact of the body mass index on stone recurrence is interesting. The gallbladder status did not predict stone recurrence in our study.

Aged↗