LABORATORY AND CLINICAL-ASSESSMENT OF PNEUMATICALLY DRIVEN INTRACORPOREAL LITHOTRIPSY

A pneumatically driven intracorporeal lithotripter (the Swiss Lithocla st) has recently been approved for use in the United States. We compar ed its performance in vitro with ultrasonic, electrohydraulic and lase r lithotripsy devices using a standard plaster-of-Paris stone phantom. The probe sizes and output settings were identical to those used duri ng clinical treatment. The fragmentation efficiency index (measured as the lithotripsy time needed to reduce the stone phantom to particles <2 mm divided by the initial stone weight) ranged from 5.0 to 8.5 min/ g of stone mass, with this value increasing from pneumatic to electroh ydraulic to laser and to ultrasonic lithotripsy. We also performed an objective study in a swine model, which showed no adverse consequence of pneumatic lithotripsy. Finally, we evaluated our initial 41 patient s who had undergone pneumatic stone fragmentation. We treated 8 patien ts having 11 renal calculi, 30 patients having 37 ureteral calculi, an d 3 patients having 6 bladder calculi employing pneumatic probes rangi ng in size from 0.8 to 2.0 mm, Stone fragmentation was successful in a single session in 95% of the ureteral calculi and 100% of both renal and bladder calculi, Stone analysis in 23 patients revealed 17 (74%) c alcium oxalate monohydrate and 1 (4%) cystine calculi, Our clinical an d laboratory assessment of this newly developed pneumatic lithotripsy device further validates its efficacy in fragmenting stone of all comp ositions and its overall safety associated with clinical application.