Clinical efficacy of a combination pneumatic and ultrasonic lithotrite

A new combination pneumatic/ultrasonic intracorporeal lithotriptor has been developed for percutaneous applications. It combines the stone clearing efficiency of an ultrasonic device with the fragmentation strength of a pneumatic probe into a single handpiece. We present our early clinical experience with this device in a prospective, randomized comparison a combination pneumatic/ultrasound lithotrite and standard ultrasonic lithotripsy.

A total of 20 consecutive patients undergoing percutaneous nephrolithotomy for symptomatic calculi were randomized to receive stone fragmentation and removal using a standard ultrasonic device or a new combination pneumatic/ultrasonic unit. Stone location and burden were assessed before the operative procedure. The stone clearance rate in mm.2 per minute was calculated for the 2 devices. Complications and stone-free rates were compared in the 2 groups.

There were no significant differences in stone location and composition in the 2 groups of patients. Average time required for complete stone clearance was considerably less for the combination device (21.1 versus 43.7 minutes, p = 0.036). The opposite was true for the average rate of stone clearance in mm.2 per minute, in that the standard ultrasonic device could clear 16.8 versus 39.5 mm.2 per minute for the combination unit (p = 0.028). Stone-free and complications rates were slightly superior for the combination device but it was likely attributable to patient factors.

The combination pneumatic/ultrasonic lithotrite is capable of disintegrating and extracting stone material at a more rapid rate than standard ultrasonic devices. Moreover, stone-free and complication rates appear to be slightly superior with the combination unit. This new combination pneumatic/ultrasonic device appears to be efficacious and safe for removing large renal calculi.