INTRACORPOREAL ELECTROHYDRAULIC LITHOTRIPSY OF URETERAL AND RENAL CALCULI USING SMALL-CALIBER (1.9F) ELECTROHYDRAULIC LITHOTRIPSY PROBES

Purpose: The development of 1.9F or smaller electrohydraulic lithotrip sy probes has facilitated the use of this form of lithotripsy via mini ature rigid and flexible ureteroscopes. We report our experience with ureteroscopic intracorporeal lithotripsy using 1.9F electrohydraulic l ithotripsy probes. Materials and Methods: A total of 45 patients (32 u reteral and 57 renal calculi) underwent retrograde rigid (microscopic to 6F short) or flexible (7.5 and 9.4F) ureteroscopy with electrohydra ulic lithotripsy using 1.9F electrohydraulic lithotripsy probes. In 17 patients (38%) there were 37 lower pole caliceal calculi (41%). Stone size ranged from 3 to 30 mm. (mean 8.5). Results: Electrohydraulic li thotripsy resulted in successful fragmentation (that is 2 mm. or small er fragments) in 98% of patients overall. It was successful after fail ure of HM-3 extracorporeal shock wave lithotripsy in 10 patients and a fter failed lithotripsy with the 140 mJ. tunable dye laser in 7. Elect rohydraulic lithotripsy resulted in successful fragmentation of 94% of lower pole caliceal stones. No intraoperative complications and no si gnificant ureteral or renal mucosal damage were noted. Fever developed postoperatively in 2 patients (4.4%) with negative urine cultures. Po stoperatively an indwelling stent was placed for 2 weeks or less in 71 % of patients and no stents were placed due to preoperative stenting i n 29%. Average hospital stay was 0.8 days (range 0 to 4). Followup ima ging in 38 patients (84%) at a mean of 8.7 months (range 2 to 28) reve aled stone-free rates of 92% overall and 87% in patients with lower po le renal calculi. No patient had a ureteral or infundibular stricture postoperatively. Conclusions: The development of 1.9F or smaller elect rohydraulic lithotripsy probes provides the urologist with a safe, hig hly effective and inexpensive method for performing intracorporeal lit hotripsy throughout the entire upper urinary tract via rigid or flexib le ureteroscopes. Furthermore, for the ureteroscopic treatment of lowe r pole renal calculi electrohydraulic lithotripsy is the only form of intracorporeal lithotripsy sufficiently malleable to allow routine acc ess.