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At least 19 recordsLinked to original sources
PubMed1994

Outpatient fragmentation of ureteral calculi with mini-ureteroscopes and laser lithotripsy.

Laser lithotripsy with mini-ureteroscopes is a minimally invasive method to fragment ureteral calculi. This study reviewed the efficacy and morbidity of outpatient laser lithotripsy for the treatment of ureteral calculi. The 248 patients were initially treated by outpatient ureteroscopy and laser lithotripsy with the Candela pulsed-dye laser over a period of 3 1/2 years. Thirty-six patients had prior unsuccessful fragmentation of ureteral calculi by SWL. Twenty-eight patients had undergone unsuccessful ureteroscopy with attempted basket extraction or attempted fragmentation with methods other than laser. Calculi were located in the upper ureter in 31% and in lower ureter in 69% of these patients. The 1-month stone-free rate was 92% for upper ureteral calculi and 96% for lower ureteral calculi, with an overall success rate of 94.7%. Ninety per cent of the patients were discharged the same day and 96% within 23 hours. Hospital admission was needed in only 4% of patients. Parenteral analgesia was required in 18% of patients, and major complications occurred in 0.8%. The combination of mini-ureteroscopes and laser lithotripsy is an effective method for fragmentation of ureteral calculi in outpatients with low morbidity and few complications.

Adolescent↗
PubMed1998

Paraureteral extrusion of calculi after endoscopic pulsed-dye laser lithotripsy.

Laser lithotripsy has become an effective and low-morbidity procedure for the treatment of ureteral calculi. Nevertheless, ureteral endoscopy is not free of side effects and complications. Lithiasis extrusion is one of the early complications of this procedure, and usually, the diagnosis is carried out by means of urographic findings because it is not easily recognized during ureteroscopy. Between January 1990 and May 1996, a total of 1047 endoscopic lithotripsies with the pulsed-dye laser were performed in our department. The 3-month stone-free rate as a single treatment was 76.5%. We found 11 cases (1.05%) of calculi extrusion after ureteral endoscopic treatment. Only one case was diagnosed intraoperatively. The evolution after a mean follow-up period of 18 months (range 6-34 months) was satisfactory in all cases. No urinary extravasation, infection, or secondary ureteral strictures were found. According to the absence of side effects, it was considered unnecessary to remove the extruded calculi. Extrusion of noninfected calculi into the periureteral tissues after laser lithotripsy causes no significant consequences and can be successfully managed conservatively. Knowledge of this possible complication is the best way to avoid it. A careful technique and a low irrigant flow will be very helpful.

Adult↗
PubMed1992

Biliary laser lithotripsy.

Laser lithotripsy is an excellent method of fragmenting those biliary stones that cannot be removed easily by less technically advanced methods such as basket extraction. The energy can be delivered through fine flexible fibers, around 200 to 320 microns in diameter, that can be passed through the channels of a variety of small endoscopes. Currently, the optimal laser seems to a pulsed system because of the conversion of light to acoustic energy with minimal heating of the surrounding tissues, thus avoiding the chance of tissue injury and perforation. The best wavelength seems to be 504 nm, because at this wavelength, there is maximum absorption of laser energy by pigment stones, resulting in fragmentation using low-energy pulses. With further research, optimal wavelengths and pulse durations may emerge.

Cholelithiasis↗
PubMed2001

Pneumatic lithotripsy versus laser lithotripsy in the endoscopic treatment of ureteral calculi.

PURPOSE: To compare the efficacy, safety, and features of pneumatic lithotripsy (PL) with those of laser lithotripsy (LL) and present our clinical experience in the endoscopic management of ureteral calculi. PATIENTS AND METHODS: From August 1994 to February 2000, 285 consecutive patients underwent endoscopic lithotripsy with either the Swiss Lithoclast pneumatic lithotripter (145 patients) or the Ho:YAG laser lithotripter (140 patients) for the treatment of ureteral calculi. RESULTS: In one single session, the overall successful stone fragmentation rate of LL was higher than that of PL (95.7% v 69.7%; P < 0.01). The average time to stone-free status was shorter for LL than for PL (18 days v 31 days; P < 0.01). No major complications were observed in LL, while five ureteral perforations were encountered in PL. CONCLUSIONS: Laser lithotripsy has advantages over PL in high efficiency of stone fragmentation and a low complication rate. Laser lithotripsy is a powerful, effective, and safe treatment modality for ureteral calculi.

Adolescent↗
PubMed1991

Interspersion of fragmented fiber's splinters into tissue during pulsed alexandrite laser lithotripsy.

Laser induced shockwave lithotripsy (LISL) on artificially inserted human renal calculi was realized in explanted pig ureters. A pulse stretched Alexandrite solid state laser was used at 750nm. Pulses of 350ns and 1 microseconds duration were transmitted through a 250 microns all silica fiber onto a stone surface, keeping the fiber tip in contact with a stone close to the ureter wall. The high power density of the 350 ns pulses lead to an optical breakdown inside the distal fiber tip causing fiber fragmentation of about 28 mm/100 pulses. Deep penetration of the fiber fragments into the ureter wall was proven histologically. Fiber fragmentation was avoided by increasing the pulse duration up to 1 microseconds. Riks for patient treatment caused by short pulse lithotripsy are discussed.

Animals↗
PubMed1994

Modes of intracorporeal lithotripsy: ultrasound versus electrohydraulic lithotripsy versus laser lithotripsy.

It seems apparent, from the previous discussion, that no form of intracorporeal lithotripsy represents the perfect treatment modality for all upper urinary-tract calculi. In fact, the role of endoscopic techniques for treatment for upper-tract calculi must be carefully considered given the success of SWL. However, not all stones are amenable to extracorporeal treatment. Therefore, ureteroscopy, with the various forms of intracorporeal lithotripsy, represents an alternative means for successfully treating patients without having to resort to surgical intervention. Ultrasonic lithotripsy is probably the least preferable of the three forms of treatment, primarily because it must be carried out with rigid endoscopic equipment. In the future, if flexible or semirigid devices can be developed, ultrasonic lithotripsy may become a more useful option for the treatment of ureteral calculi. Laser lithotripsy and EHL seem to be equally well suited for use with flexible, actively deflectable ureteroscopes. The relative risks and benefits of these two modalities make their use a matter of clinician's choice. The greater risk of ureteral injury may make EHL somewhat less attractive to endoscopists. However, this must be balanced with the increased cost of the laser lithotripter. It has become apparent that a direct comparison of these three types of intracorporeal lithotripsy is difficult because of the lack of standardized data and the scarcity of randomized comparative trials. Despite this, it appears that all three forms of intracorporeal lithotripsy play an integral part in the treatment of upper-tract urinary calculus disease. Certainly, one of the more exciting areas in the field of endourology will be the continued emergence and development of new technologies and devices for these purposes.

Endoscopy↗
PubMed1994

Use of an absorbent in laser lithotripsy with dye lasers: in vitro study of fragmentation efficiency and jet formation.

Among other things, the fragmentation efficiency of laser lithotripsy using a dye laser depends upon the physical properties of the surface of the calculus, especially optical absorption. In this in vitro study we were able to increase the fragmentation efficiency on white, nonabsorbing calculi by introducing an absorbing liquid between the distal end of the fiber and the stone surface. This absorbing liquid (in our case potassium dichromate) provides a reliable plasma ignition and thus makes the fragmentation independent of the properties of the stone surface. Furthermore, we examined and documented the existence of liquid jets that were produced by the collapse of a cavitation bubble near a stone. We observed considerable fragmentation effects on artificial stones that were, however, inferior to those achieved with the fiber in contact with the stone. This work suggests that the effects of a liquid jet should be taken into consideration when using a holmium:YAG laser for lithotripsy.

Light↗
PubMed1988

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

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.

Humans↗
PubMed1993

Cost-efficacy comparison of extracorporeal shock wave lithotripsy and endoscopic laser lithotripsy in distal ureteral stones.

Distal ureteral stones are usually treated today by extracorporeal shock wave lithotripsy or extraction by retrograde ureteroscopy with or without previous fragmentation. We performed a cost-efficacy study of three methods to treat them: extracorporeal lithotripsy using either a spark gap lithotripter, the unmodified Dornier HM3 (SWL), or the piezoelectric Wolf Piezolith 2300 (EPL) and endoscopic lasertripsy (LISL) using an alexandrite pulsed laser, the HMT Alexantriptor. The records of 520 patients with distal ureteral stones treated by extracorporeal lithotripsy were reviewed to establish the mean cost of the procedure. Concerning LISL, the first 30 stone patients treated in our institution were evaluated. Four measures were examined: (1) number of sessions; (2) success rate; (3) auxiliary maneuvers; and (4) complications. The economics evaluation considered the direct costs related to personnel, consumables, depreciation, and maintenance. The EPL procedure was the cheapest: $873 US, and SWL the most expensive: $3,572 US. The best cost-efficacy rate was seen with LISL because of its 93% success rate and its cost of $1,390 US.

Cost-Benefit Analysis↗
PubMed1998

Outpatient treatment of middle and lower ureteric stones: extracorporeal shock wave lithotripsy versus ureteroscopic laser lithotripsy.

The aim of this retrospective study was to evaluate the efficacy of ureteroscopic lithotripsy (URSL) and extracorporeal shock wave lithotripsy (ESWL) in the treatment of middle and lower ureteric stones. From January 1996 to March 1997, 61 patients treated by URSL and 49 patients treated by ESWL were studied, both were conducted as outpatient procedures. URSL using Holmium laser and semirigid ureteroscope (Fr.8.5) performed under general anaesthesia had single session stone clearance rates of 100% and 95% for middle and lower stones respectively. There were 6 complications including 5 readmissions (2 febrile episodes, 2 severe pain spells, and 1 stent migration) and 1 stricture formation. ESWL using the Dornier MFL 5000 lithotriptor had a single session success rate of 51% and overall success rate of 78% after retreatment (retreatment rate 35%). No significant complication or readmission was noted. Seventy-two per cent of patients required intravenous fentanyl for pain control. The efficiency quotients calculated for the URSL group and the ESWL group were 97% and 58% respectively. In summary, in the treatment of middle and lower ureteric calculi, ESWL carries reasonable success rate, especially with retreatment; and minimal morbidity. On the other hand, URSL is highly effective in rapidly clearing the stones, a low risk of complication is noted. Both can be conducted as an outpatient treatment modality.

Adult↗
PubMed1990

[Laser lithotripsy with the neodymium YAG laser].

Laser-induced shock wave lithotripsy (LISL) with a Q-switched neodymium-YAG laser depends on the generation of a laser-induced breakdown in the fluid surrounding the stone. An oscillating plasma bubble is created, directing shock waves towards the stone. These cavitational effects fragment the calculus into small particles. A new bifunctional laser is introduced: this allows both nanosecond pulses for shock wave generation and disintegration of urinary calculi and millisecond pulses for biliary stones and tissue coagulation. It can be supplied with 320-, 400-, and 600-micron fibers. We have treated 189 ureteric stones in 185 patients with laser lithotripsy utilizing flexible ureteroscopes (n = 26) or rigid ureteroscopes (n = 159). It proved possible to fragment 179 stones into small pieces. In eight patients LISL was not successful. A rigid cystoscope that can be dismantled into an upper and lower hemisheath for the introduction of flexible endoscopes into the ureter without prior dilatation of the ureteral orifice was used in 15 patients.

Cystoscopes↗
PubMed1996

Peroral laser lithotripsy of difficult intrahepatic and extrahepatic bile duct stones: laser effectiveness using an automatic stone-tissue discrimination system.

OBJECTIVES: The use of laser lithotripsy with an integrated stone-tissue discrimination system is an ambitious treatment modality for bile duct stone fragmentation. The aim of our prospective study was to determine the effectiveness and safety of the laser system and to find whether it reduced the need for choledochoscopy. METHODS: Thirty patients with complicated bile duct stones were treated perorally with a flashlamp-pulsed Rhodamine-6G dye laser and an automatic stone-tissue discrimination system. Initial treatment sessions were performed under fluoroscopic guidance in each patient and switched to choledochoscopic control if the stone could not be approached properly. RESULTS: Eighteen of 19 patients with extrahepatic bile stones were treated under fluoroscopic control; 17 of 19 patients were successfully treated through laser therapy. In nine of the patients with intrahepatic stones (n = 11), choledochoscopy was necessary for sufficient laser lithotripsy; seven of those patients became stone-free. Twenty-four of 30 patients (80%) were stone-free after sole laser therapy. Combined with other methods, the overall success rate was 27/30 (90%). Therapy-related mortality was 0%. CONCLUSIONS: Laser lithotripsy is effective and safe. The stone-tissue discrimination system facilitates therapy under fluoroscopic control and precludes the need for choledochoscopy, which is highly significant (p <0.001) if the calculi are extrahepatically located.

Adult↗
PubMed1993

Laser lithotripsy. Patient care, staff education.

The high cost of laser equipment and the required specialization of staff members make extension of laser lithotripsy to every hospital impractical. At present, in Ontario, laser lithotripsy is available only in Toronto and Kingston, and ESWL is available only in Toronto and London. Laser lithotripsy is a viable alternative to invasive surgical treatment of urinary calculi that are resistant to ESWL. For the suitable candidate, laser lithotripsy is a welcome alternative to an extensive surgical procedure and recovery period. Hospitalization is reduced significantly, and patients can return to work after the calculus and residue have been passed. Patients can be managed safely and effectively, resulting in reduced morbidity and mortality and reduced cost in time and expense to the patient and hospital.

Equipment Safety↗
PubMed1995

Laser lithotripsy in pregnancy. A case report.

Laser lithotripsy is a new method of treating symptomatic urolithiasis. The pulsed dye laser lithotripter uses coumarin to deliver energy with a visible peak wave-length of 504 nm. This energy is transmitted to the calculus through an optical fiber, and mechanical disruption of the stone occurs when multiple pulses of laser energy are applied to the surface of the stone. The method is safe and effective for impacted ureteral calculi. A woman at 20 weeks of pregnancy experienced intractable pain secondary to a 9-mm, distal ureteral stone. She was treated successfully with endoscopic fragmentation using pulsed dye laser lithotripsy.

Adult↗
PubMed1998

Color vision deficits during laser lithotripsy using safety goggles for coumarin green or alexandrite but not with holmium:YAG laser safety goggles.

PURPOSE: Laser lithotripsy requires urologists to wear laser eye protection. Laser eye protection devices screen out specific light wavelengths and may distort color perception. This study tests whether urologists risk color confusion when wearing laser eye protection devices for laser lithotripsy. MATERIALS AND METHODS: Urologists were tested with the Farnsworth Dichotomous Test for Color Blindness (D-15) and the Farnsworth-Munsell 100-Hue Test (FM-100) without (control) and with laser eye protection devices for coumarin green, alexandrite and holmium:YAG lasers. Error scores were tabulated. The pattern of color deficits was characterized with confusion angles, confusion index (C-index), scatter index (S-index) and color axes. Laser eye protection devices were tested with spectrophotometry for spectral transmittance and optical density. RESULTS: The D-15 transposition errors (mean plus or minus standard deviation) for control, holmium:YAG, alexandrite and coumarin green laser eye protection were 0 +/- 0, 0 +/- 0, 0.3 +/- 0.5 and 6.4 +/- 1.6, respectively (p = 0.0000001). The FM-100 error scores (mean plus or minus standard deviation) were 20 +/- 15, 20 +/- 14, 91 +/- 32 and 319 +/- 69, respectively (p = 0.0001). The confusion index scores indicated a mild color confusion for the alexandrite and pronounced color confusion for the coumarin green laser eye protection. The confusion angles and scatter indexes mimicked a congenital blue-yellow deficit for coumarin green laser eye protection. Color axes showed no significant deficits for control or holmium:YAG laser eye protection in any subject, red-green axis deficits in 3 of 6 tested with alexandrite and blue-yellow axis deficits in 12 of 12 tested with coumarin green (p < 0.001). Spectrophotometry showed that laser eye protection for coumarin green blocks light less than 550 nm., alexandrite blocks light greater than 650 nm. and holmium:YAG blocks light greater than 825 nm. CONCLUSIONS: Laser eye protection for coumarin green causes pronounced blue-yellow color confusion, whereas alexandrite causes mild red-green color confusion among urologists, holmium:YAG causes no significant color confusion compared to controls. The differences are explained by laser eye protection spectrophotometry characteristics and visual physiology.

Adult↗