Comparison of methods for transcatheter fragmentation of gallstones

Alternative methods have been considered for treating cholelithiasis. Compared to extracorporeal shockwave lithotripsy (ESWL), a percutaneous endoscopic approach would be more invasive, but would offer the advantage of immediate stone removal without the need for subsequent drug therapy. We performed an in vitro comparison of three methods of transcatheter cholecystolithotripsy with regard to effectiveness of stone fragmentation, damage to the gallbladder mucosa, and compatibility with percutaneous delivery systems. The three devices used for cholecystolithotripsy were the ultrasonic lithotriptor (UL), the electrohydraulic lithotriptor (EHL), and the thulium-holmium-chromium: YAG laser (THC:YAG). The UL effectively fragmented all types of stones studied, although it is necessary to hold the stone against the tip of the probe. The EHL quickly fragmented noncalcified and pigment stones simply by placing the tip in the vicinity of the stone, but calcified stones had to be held in position near the electrode. The THC:YAG was effective at fragmenting each type of stone, but the number of pulses required was quite large, corresponding to 7 min for some stones. The EHL had the most capacity for mucosal damage, followed by the THC:YAG laser. The UL produced no mucosal damage at the exposure times tested. The UL is not compatible with flexible endoscopes while the EHL and the THC:YAG are. Because of the specific advantages and disadvantages of each device, a combination of devices may be required for successful clinical cholecystolithotripsy.