Search

Background and Objective The objective of this study was to evaluate clinical use of an Alexandrite laser lithotripter for intracorporeal lithotripsy of urinary calculi. Study Design/Materials and Methods: We prospectively evaluated a flash lamp pumped, Q-switched Alexandrite solid-state laser for use in conjunction with ureteroscopy (30 cases) or percutaneous nephrolithotripsy (2 cases). The laser operates at a wavelength of 755 nm in a pulsed mode with pulses of 150–800 ns duration at energy settings of 30–80 mJ. Results The fragmentation rate with the Alexandrite laser alone was 50% (16/32). Failure of the laser was due to equipment malfunction or technical problems in 11 cases and inability to fragment the stone in 5. All cases of failed Alexandrite laser lithotripsy were successfully salvaged with alternative modalities of endoscopic stone destruction and removal. One intraoperative complication, a ureteral perforation, occurred; however, no long-term sequelae related to laser use was documented. Conclusion Clinical results with the Alexandrite laser appear to be inferior to those reported with alternative laser systems and other forms of intracorporeal lithotripsy. Whereas some of the inadequacies we have noted may be addressed in the future by modifications in the unit and delivery systems, we would not recommend this device for intracorporeal lithotripsy of urinary calculi in its current form. Lasers Surg. Med. 20:433–436, 1997. © 1997 Wiley-Liss, Inc.

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.

Currently three modalities are available for intracorporeal stone fragmentation--electrohydraulic, ultrasound and laser lithotripsy. A new device, the Swiss Lithoclast, has been developed by the Departments of Medical Electronics and Urology at the University of Lausanne, Switzerland. This device has been used clinically in several countries for the treatment of stones throughout the human urinary tract. While no adverse outcomes have been reported, the potential tissue effects of the device have not been thoroughly investigated in an animal model. The objective of the present study is to evaluate the possible acute and long-term tissue effects of this instrument on the pig urinary tract. In all acute animals, visible mucosal lesions were seen at the site of probe firing in the bladders and ureters. Histologic examination demonstrated the effects of acute trauma with edema, hemorrhage and mucosal denudation. No significant long-term tissue effects were noted either pathologically or on radiographs in the 3- and 6-week animals. This study confirms our clinical impression that the Swiss Lithoclast effectively fragments urinary calculi and is associated with a large margin of safety.

Modalities available for performing intracorporeal lithotripsy include ultrasonic, electrohydraulic and laser procedures. We present our experience with a new and unique technology for performing intracorporeal lithotripsy, namely the Swiss Lithoclast. This simple and inexpensive device uses compressed air to activate a solid probe in a manner similar to that of a jackhammer. We report the use of the Lithoclast in 31 cases, consisting of 6 renal calculi approached percutaneously, 17 ureteral calculi and 8 bladder calculi. The Lithoclast successfully fragmented 94% of the calculi. There were no intraoperative or long-term complications directly related to the use of this device. We have found the Swiss Lithoclast to be a safe, effective and inexpensive means of performing intracorporeal lithotripsy for calculi located throughout the urinary tract.