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At least 19 recordsLinked to original sources
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↗
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↗
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↗
PubMed1991

Laser lithotripsy: a nursing perspective.

Laser lithotripsy represents the urologist's newest option in urinary stone management and is fast becoming the procedure of choice when treating calculi. Approximately 400,000 people yearly require treatment for urinary stone disease. 60% pass the calculi spontaneously while 40% require some type of intervention (Dretler, 1988). While the initial cost of the laser is expensive, maintenance cost is relativity low. Therefore, the laser lithotripter becomes a very cost effective tool when compared with other alternatives because of the decreased hospital stay and the absence of significant complications. Adverse effects to the patient are primarily due to the endoscopic procedure and not the laser itself. Additional benefits to the patient include reduced pain and edema, minimal bleeding, no incision and decreased convalescence time.

Humans↗
PubMed1990

Laser lithotripsy in the treatment of ureteral calculi.

We examined the effectiveness of laser lithotripsy with a flash-lamp-pumped tunable dye laser in the treatment of ureteral calculi that were too large for direct extraction and that could not be treated with or had not responded to extracorporeal shock-wave lithotripsy (ESWL) or forms of ureteroscopic lithotripsy other than laser lithotripsy. In 20 (74%) of the 27 patients the laser alone successfully fragmented the calculi into pieces small enough to pass spontaneously or to be easily extracted with a basket. In five (19%) laser lithotripsy was partially successful: another procedure (ESWL in three and fragment extraction with a basket in two) was needed. In two patients (7%) the stones could not be fragmented with the laser, and either ESWL or percutaneous antegrade extraction was performed. At follow-up 3 months after treatment there was no sign of stone fragments in 26 (96%) of the patients. We believe that laser lithotripsy is a safe and effective method of ureteral stone fragmentation.

Follow-Up Studies↗
PubMed1992

[Percutaneous transhepatic cholangioscopic color laser lithotripsy in bile duct calculi].

Tunable dye laser lithotripsy is an effective and low risk treatment in patients with bile duct stones in which transpapillary maneuvers failed. The percutaneous approach allows to introduce small caliber endoscopes (10.5 F) to fragment the calculi under vision. This technique was evaluated in 8 patients who had undergone a biliodigestive anastomosis or in whom the biliary calculi could not removed by standard retrograde treatment. Laser lithotripsy resulted in sufficient fragmentation in 7 patients. Bile duct clearance proved to be a particular problem with the percutaneous access. When a retrograde sphincterotomy is not possible an antegrade papillotomy must be attempted under fluoroscopic guidance. In bile duct strictures the implantation of expandable stents facilitates the passage of fragments and may prevent recurrent stricture and development of new stones.

Aged↗
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↗
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↗
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↗
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↗
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↗
PubMed1992

Pulsed dye laser lithotripsy--the Toa Payoh Hospital experience.

We report our experience with pulsed dye laser lithotripsy in the treatment of 100 ureteric stones in 95 patients over a 14-month period from July 1989 to September 1990. The overall rate of successful stone fragmentation was 97%. There was a low incidence of minor complications--mild haematuria, ureteric colic and urinary tract infection; ureteric perforation occurred in only 3 patients, all of whom were successfully treated conservatively. Pulsed dye laser lithotripsy is a safe and effective mode of treatment for ureteric stones. Current indications for laser fragmentation of stones are ureteric stones, impacted pelviureteric junction stones and Steinstrasse.

Adult↗
PubMed1991

Transhepatic laser lithotripsy of choledocholithiasis: initial clinical experience.

Three patients with symptomatic intra- and extrahepatic choledocholithiasis who were not good candidates for retrograde endoscopy, surgery, or extracorporeal shock wave lithotripsy (ESWL) were treated successfully with endoscopically guided tunable dye laser lithotripsy via a 12-F transhepatic sheath. There were no complications secondary to the use of the laser. On the basis of this initial experience, transhepatic laser lithotripsy is a technically feasible and safe alternative when choledocholithiasis cannot be managed with retrograde endoscopy, ESWL, or surgery. Its role in the management of choledocholithiasis relative to other transhepatic techniques remains to be determined.

Adult↗
PubMed1991

Endoscopic laser lithotripsy: safe, effective therapy for ureteral calculi.

At our lithotripsy department more than 400 patients with renal or ureteral calculi have been treated with a pulse-dye laser for stone disease. We review our experience during an 11-month period when a total of 223 patients was treated. Of these patients 204 whose ureteral calculi were treated by laser lithotripsy are available for followup. The data in this series demonstrate that a miniaturized ureteroscopic system is of paramount importance in laser lithotripsy, allowing access into the ureter without dilation in the majority of patients (165 of 204). Lack of dilation is associated with a decrease in pain and postoperative hospitalization. Satisfactory stone fragmentation was accomplished in 198 of 204 procedures in this series with use of the laser alone. A low complication rate was observed. Endoscopic laser lithotripsy is a safe, reliable and cost-effective method of therapy for ureteral calculi in a community hospital setting.

Endoscopes↗
PubMedDate not supplied

Endoscopic pulsed dye laser lithotripsy of gallbladder calculi in vivo.

We have evaluated the efficacy and safety of pulsed dye laser lithotripsy of gallbladder calculi using a percutaneous endoscopic technique in a porcine model. Fragmentation was readily achieved in vivo. Using a combination of laser lithotripsy and saline lavage, complete removal of all stone debris was feasible through a 24 F tract (N = 3). However, the degree of fragmentation required rendered removal through a smaller tract inefficient, a mean 53% of stone mass being retrievable through a 16 F tract (N = 11). Repeated laser activation at 1 mm from the gallbladder mucosa produced minimal injury, regardless of pulse energy. When the laser fiber was pressed against the mucosa, perforation of the gallbladder was possible at therapeutic pulse energy, but this did not lead to clinical sequelae. We conclude that the pulsed dye laser is a safe and effective means of fragmenting gallbladder calculi in vivo.

Animals↗
PubMed1992

Endoscopic laser lithotripsy with an automatic stone recognition system for basket impaction in the common bile duct.

In a patient with a common bile duct stone 28 mm in diameter, the traction wires of two basket catheters fractured during endoscopic mechanical lithotripsy. Disintegration of the concrement and removal of the impacted baskets failed even after extracorporeal application of 8,000 shockwaves. Pulsed dye laser lithotripsy was carried out via a 250 microns fiber which was advanced to the stone through a 6 French ERCP guiding catheter. Lithotripsy could be safely performed under fluoroscopic control since the laser used provides an automatic cut-out system upon tissue contact. 3,600 of 11,800 applied pulses were emitted with the total power setting and complete disintegration of the calculus was achieved. The baskets and the fragments could be removed endoscopically in the same session. Laser lithotripsy with a stone recognition system would seem to improve the applicability and safety of intracorporeal lithotripsy even when performed without direct visual guidance.

Aged↗
PubMed1992

Laser lithotripsy of the difficult ureteral calculus: results in 122 patients.

We studied 122 patients with ureteral calculi who could not be treated by extracorporeal shock wave lithotripsy (ESWL) because the stones could not be localized or focused for treatment, the patient had failed prior ESWL, the stones were impacted and in situ ESWL was likely to fail or the stones were proximal to a ureteral stricture. These patients underwent laser lithotripsy using the Candela pulsed dye laser. In 107 patients (88%) the calculi were completely fragmented with the laser alone, while 10 (8%) needed another procedure (ESWL in 8 and stone fragment extraction by basket in 2), and 5 (4%) had failed laser therapy and needed some other form of treatment (ESWL in 4 and percutaneous antegrade extraction in 1). At 3 months 116 of 122 patients (95%) were stone-free. There were 2 immediate complications (ureteral perforations) and 1 late complication (ureteral stricture). Laser lithotripsy is a safe and effective method of intracorporeal fragmentation, even of the difficult ureteral calculus, and it is a useful adjunct to ESWL.

Adolescent↗