INTRACORPOREAL OR EXTRACORPOREAL LITHOTRIPSY FOR DISTAL URETERAL CALCULI - EFFECT OF STONE SIZE AND MULTIPLICITY ON SUCCESS RATES

Over a period of 57 months, 404 patients with distal ureteral calculi were treated by in situ SWL on a Storz Modulith SL 20 lithotripter and 163 by ureteroscopy (URS) and Swiss Lithoclast stone fragmentation. T he case notes on these patients were reviewed for comparison of the in itial stone number and individual length and for the calculation of th e stone-free, treatment, retreatment, secondary procedure, and complic ation rates. Complete data were available on 447 patients. The median stone length was 7.0 (range 4-25) mm in the SWL group and 8.0 (range 5 -13) mm in the URS group. The single-treatment stone-free rates for th e SWL and URS groups were 74.8% and 89.7%, respectively, for single st ones and 50.0% and 88.9%, respectively, for multiple (>1) stones. The mean treatment rates for the SWL and URS groups were 1.97 and 1.03, re spectively, for single stones and 2.83 and 1.00, respectively, for mul tiple stones. The mean treatment rate for single stones subjected to S WL increased with increasing stone length (1.57 for stones <8 mm and 2 .38 for stones >8 mm), whereas this was not the case for patients subm itted to URS (1.20 and 1.27, respectively). The retreatment rate for e ach group showed a reciprocal trend. Of the SWL group, 25.9% of the pa tients eventually required URS to render them stone-free. Nearly all ( 96%) of the patients undergoing SWL were treated as outpatients. The m ean hospitalization in the URS group was 1.1 days, Three patients who underwent URS sustained a ureteral perforation, which was managed succ essfully by double-J stent insertion. The ideal primary treatment for small (<8 mm) distal ureteral calculi is in situ SWL, with URS plus Li thoclast fragmentation being reserved for failed SWL, single stones >8 mm in length, and multiple stones.