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A case of acute cholecystitis in a high risk patient was treated in the acute phase with cholecystostomy guided by ultrasound and with introduction of a pig-tail catheter for drainage. Later, percutaneous laser lithotripsy was undertaken via a flexible choledochoscope. The recent percutaneous therapeutic principles and the possibilities in biliary calculous disease are reviewed.
Lithotripsy with the pulsed-dye laser has been shown to be a safe and effective method of intracorporeal urinary stone fragmentation. Recently, a new device, the holmium: YAG laser, has been developed with both soft tissue and lithotripsy applications. We present our preliminary experience with the Ho:YAG laser for lithotripsy of urinary calculi. Ureteroscopy and lasertripsy resulted in successful fragmentation of ureteral stones in 92% of 21 patients when the laser was used alone or in combination with electrohydraulic lithotripsy. One complication directly related to the use of the laser occurred, a ureteral perforation, when the device was utilized under fluoroscopic control. In four patients undergoing percutaneous flexible nephrolithotripsy, the laser demonstrated utility in fragmenting caliceal stones remote from the nephrostomy tract. In summary, the Ho:YAG laser has demonstrated its efficacy as a method of intracorporeal lithotripsy. The tissue effects of this device, as well as the optimal energy/pulse and frequency settings, need further evaluation in order to minimize the risks of tissue injury.
The holmium:YAG laser has been used effectively for a wide variety of urinary calculi. No cases have been reported of its in vivo use in the biliary system. In this report, we describe its utility in intracorporeal lithotripsy of intrahepatic biliary stones and the urologist's role in providing expertise in small-caliber endoscopy and lithotripsy to other disciplines.
An in vivo study was performed to evaluate the use of pulsed-dye laser beam for the fragmentation of salivary calculus. In accordance with the absorption and reflection spectra of sections of salivary stones, optimal fragmentation was achieved with a pulsed-dye laser with a pulse width of 1.4 microns and tuned to a wavelength of 504 nm. Further studies on particle size were conducted, and a new "sialoendoscope" technique was developed. Fifteen patients with sialolithiasis of the submandibular gland were treated. Under continuous endoscopic monitoring laser-induced shock wave lithotripsy was performed. In six patients complete fragmentation and removal of the salivary stones was achieved and in another patient 50 per cent fragmentation was sufficient to restore salivary flow. Laser lithotripsy of salivary stones with endoscopic monitoring permits treatment on an outpatient basis with little inconvenience to the patient, and this is a breakthrough in otolaryngology.
BACKGROUND AND OBJECTIVES: The high-power Thulium fiber laser has previously been shown to rapidly vaporize and coagulate soft urinary tissues (e.g., prostate). This is the first preliminary study of a high-power Thulium fiber laser for fragmentation of urinary stones. STUDY DESIGN/MATERIALS AND METHODS: A continuous-wave, high-power Thulium fiber laser operating at a wavelength of 1.94 microm, was modulated to operate in pulsed mode with an output pulse energy of 1 J through a 300-microm-core silica fiber at a 20 milliseconds pulse length and repetition rate of 10 Hz. The fragmentation time to reduce uric acid (UA) (n = 13) and calcium oxalate monohydrate (COM) (n = 6) stones into particles < 2 mm was measured. RESULTS: Mean initial mass of the UA and COM stones measured 860+/-211 and 763 +/- 204 mg. Fragmentation rates measured 388 +/- 49 and 25 +/- 2 mg/minute. Average time needed to fragment the UA and COM stones into particles < 2 mm was 2.25 +/- 0.63 and 30.7 +/- 8.4 minutes, respectively. CONCLUSIONS: The high-power Thulium fiber laser, when operated in pulsed mode, is capable of fragmenting both soft (UA) and hard (COM) urinary stones. The Thulium fiber laser may be useful as a single laser system for use in multiple soft and hard tissue laser ablation applications in urology.
We used a pulsed tunable dye laser (operating at 60 mJ per pulse, 504-nm wavelength) to fragment large (0.8-4.5 cm) stones retained in the hepatic ducts or common bile duct in 12 patients after cholecystectomy. Attempts to extract stones via a T-tube or endoscope had been unsuccessful in all patients. In nine of 12 patients, all stone fragments were successfully eliminated during the initial treatment. In one patient, fragmentation occurred but debris remained, requiring endoscopic stenting. Pseudomonas sepsis developed in this patient 30 days after the procedure and was treated by extraction of the stone fragments. Fragments remaining after lithotripsy were cleared at the same sitting by using saline flushing or endoscopic or percutaneous basket extraction. In two of 12 patients, the treatment was unsuccessful because of laser malfunction. The treatment was performed without complications, except for clinically insignificant hyperamylasemia, which occurred in two patients. Our experience suggests that laser lithotripsy offers a safe alternative for nonsurgical treatment of large retained biliary stones for patients in whom traditional treatments have failed.
The pulsed dye laser is safe and effective in lithotripsy of biliary and pancreatic ductal stones, however delivery of the laser energy to the site of the calculi is technically difficult. A 3.4 mm miniscope inserted through a standard duodenoscope was used for transpapillary laser application under direct vision in one patient with an impacted pancreatic stone and in three patients with bile duct stones not amenable to treatment by routine endoscopy. Lithotripsy and ductal clearance was achieved in 3 of the 4 patients within a single treatment session. Percutaneous transhepatic laser lithotripsy via a 3.7 mm miniscope succeeded in the patient in whom the peroral approach had failed and in two further patients with bile duct stones not accessible by a retrograde approach. There were no major complications. The miniscopes provide an appropriate direct visual control for laser lithotripsy of pancreatobiliary calculi. This approach using miniscopes seems to be an effective, minimally invasive and time-saving alternative to conventional endoscopic laser lithotripsy.
Experimental work has established that the Candela (Candela Laser Corporation, Wayland, MA) flashlamp excited dye laser (wavelength, 504 nm) is a highly effective method for fragmenting biliary stones and has minimal potential for injuring the bile duct wall. This technique was evaluated in 25 complex patients whose stones, usually because of large size, did not respond to standard nonoperative treatment. The laser imaging was applied through a quartz fiber and aimed either under direct vision with choledochoscopes passed percutaneously or through a special "mother" duodenoscope or under fluoroscopic guidance at standard duodenoscopy. Laser treatment resulted in some fragmentation of stones in 23 cases. Subsequently, it proved that it was possible to clear the bile duct of stones in 20 patients, 12 of them receiving successful treatment during the same endoscopic procedure. There were no significant complications. This endoscopic technique seems to be a useful new alternative to surgery in patients with large and difficult bile duct stones.
The tissue effects of pulsed dye laser (Pulsolith) were studied in 10 dog ureters. The results show the absence of ureteric perforation or damage to adjacent organs by the laser irradiation. The only lesions observed were focal hyperplasia of the urothelium and chorion with extremely limited abrasions of the urothelium. The absence of tissue damage of the pulsed dye laser allows it to be used in human clinical practice.
The in vitro evaluation of a pulsed Nd:YAG laser, showed an effective and fine fragmentation of urinary calculi and showed only minimal subepithelial bleeding in the directly irradiated canine ureter. Since 1989 we have treated ureteral calculi in 30 patients. The laser pulses of 15-20 mJ (at fiber tip), 20 ns, 20-25 cps are transmitted by a 300-microns quartz fiber with a specially formed tip focusing the light. The fiber is passed through an 11.5-F ureteroscope within a guide tube, or, without a guide tube, through one of the new minimized ureteroscopies and is placed in front of the calculus. In 27 patients the procedure was successful, without any residual concretions after 1 day. In our opinion the advantages of this method are the very fine-grained, complete fragmentation of all sorts of calculi, the highly atraumatic procedure, and the absence of either optical or acoustic irritation to the operator.
An in vitro study was performed to examine the application of a laser beam for the fragmentation of salivary stones. In accordance with the absorption and reflection spectra of sections of salivary stones, optimal fragmentation was achieved using a pulsed excimer laser with a pulse width of 60 ns and a wave-length of 308 or 351 nm. Further studies on particle size were conducted and a new "sialoendoscope" technique was developed. Twelve patients suffering from a sialolithiasis of the submandibular gland were treated. Under continuous endoscopic monitoring a laser-induced shock wave lithotripsy was performed. In 11 cases complete fragmentation and removal of the salivary stones was achieved. This approach to laser lithotripsy of salivary stones with endoscopic monitoring represents a novel method that permits treatment on an outpatient basis under local anaesthesia, with little inconvenience to the patient.
OBJECTIVE: This paper reviews the current use of laser techniques for the treatment of biliary stones. BACKGROUND DATA: Biliary stones may pose a special problem when access to them is limited, when previous attempts of removal have failed, or when a less invasive option than surgery is needed. The availability of various laser sources and the adaptation of the technology for safe use in the biliary system make the use of laser energy for stone fragmentation possible. METHODS: Current literature is reviewed concerning the use of laser for biliary lithotripsy, including experimental data and experience with human series. Technology, indications, alternatives, and cumulative world experience are discussed. CONCLUSIONS: Recent technical advances have made the use of laser energy for fragmentation of biliary calculi possible. It is a valid option for treatment of "difficult" stones, when other methods have failed or as a primary treatment in certain situations. The technical complexity and the high cost limit its use for specialized centers.
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We treated 225 patients with 227 ureteral calculi (5 steinstrasse) via the pulsed dye laser with 9.5F rigid, 7.2F semirigid and flexible, steerable ureteroscopes. The 222 calculi (excluding steinstrasse) were fragmented by laser alone in 141 cases (64%), laser and a basket in 30 (13%), and laser and extracorporeal shock wave lithotripsy in 33 (15%). The laser failed in 18 cases (8%). Of the 222 calculi 165 were impacted. Of 29 impacted upper ureteral calculi 15 were treated by laser disimpaction and fragmentation, 13 by laser disimpaction followed by extracorporeal shock wave lithotripsy and 1 by an operation. Of 42 mid ureteral calculi (30 impacted) 24 were treated successfully by laser fragmentation and 14 by fragmentation followed by extracorporeal shock wave lithotripsy, while 4 failed laser therapy. Among 151 lower ureteral and tunnel calculi laser fragmentation was successful in 132 cases (87%), laser followed by extracorporeal shock wave lithotripsy was successful in 6 and 13 failed laser treatment. There were no ureteral strictures and no ureteral injuries related to use of the laser. The pulsed dye laser is safe and effective treatment for impacted upper and mid ureteral calculi, small mid ureteral calculi in female patients, and lower ureteral calculi in male and female patients. Use of the laser in conjunction with other endourological methods resulted in the need for an operation in 2 of 225 patients (0.9%) with ureteral calculi.
Four techniques of intracorporeal lithotripsy are now available: ballistic, ultrasonic, electrohydraulic, and laser. Their therapeutic efficacies have generally been evaluated and compared, but very few data have been available on their relative risks of iatrogenic trauma to the urothelial wall. We conducted a comparative analysis of this risk by testing the pig ureteral and bladder wall with the EMS Lithoclast, Olympus ultrasonic lithotripter, Walz Lithotron EL 23, and Versa Pulse Ho:YAG Coherent Laser. We measured the number of shockwaves or the energy required to perforate the ureter and bladder by delivering shocks perpendicular to the walls. Ureteral perforation was impossible with the 1.0-mm Lithoclast transducer and the 1.5-mm ultrasound transducer. Perforation was induced after 250 shocks with the 0.8-mm Lithoclast transducer, after 110 shocks with the 3F electrohydraulic electrode, and after 0.02 kJ with the laser. Bladder perforation was impossible with the 2.0-mm Lithoclast device and the 3.4-mm ultrasound transducer but was induced after 0.04 kJ had been delivered with the laser. We evaluated the iatrogenic risk under normal conditions of use by delivering the shocks tangentially to the ureteral wall and perpendicular to the bladder wall. We sacrificed animals on days 0, 1, and 6. The immediate histologic lesions induced by the Lithoclast and the ultrasound lithotripter were similar, consisting of a moderate reduction of the epithelial layers or intraepithelial detachments. Electrohydraulic shocks induced almost complete abrasion of the urothelium, and the laser induced extensive lesions of partial or complete necrosis of the urothelial wall.(ABSTRACT TRUNCATED AT 250 WORDS)
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OBJECTIVE: To observe morphological changes in the urothelium after exposure to laser beam and electrohydraulic spark. MATERIALS AND METHODS: The pulse dye laser lithotripter (MDL-2, Candela Corporation, Boston, USA) and the electrohydraulic lithotripter (AEH-2, Circon ACMI Corporation Stamford, USA) were used directly on the bladder mucosa in six pigs. Immediately after treatment, the bladder mucosa was prepared for light microscopic and scanning electron microscopic examination. RESULTS: Both electrohydraulic spark and laser beam caused mucosal denudation, submucosal swelling and haemorrhage. There was a positive correlation between the degree of urothelial damage and the power and pulse numbers applied. CONCLUSION: Direct contact of the urothelium in patients treated with laser beam or electrohydraulic spark should be avoided.