Comparative study of extracorporeal shock wave lithotripsy outcomes for proximal and distal ureteric stones.

Objective: To assess the efficacy of extracorporeal shock wave lithotripsy (ESWL) monotherapy for isolated proximal ureteral calculi and compare it to that for isolated distal calculi.

Methods: We treated 68 patients with isolated ureteral stones using MPL 9000. Stones were located in the proximal and distal ureters in 44 and 24 patients, respectively. Patients were stratified according to stone burden and degree of obstruction. Data of all patients were prospectively collected for stone burden, stone localization, number of sessions, number of shock waves, stone-free rates (SFRs), complications, re-treatment rates and auxiliary procedures. Outcomes regarding ureteral localization were compared.

Results: The overall SFR was 85.3% with a 41.2% re-treatment and 17.6% auxiliary procedure rate. The mean number of shock waves applied for each stone was not different among the two ureteral locations. The SFRs were 86.3% and 79.1% for proximal and distal ureteral stones, respectively (P=0.17). For the group with stones <100 mm(2), the SFR was 85.4% and 89.5% for the proximal and distal ureter, respectively. Although the degree of obstruction did not affect SFR of the entire group (P=0.12) and the proximal ureter group (P=0.96), it adversely affected SFR in the distal ureter (P=0.017).

Conclusions: ESWL outcomes for the ureteral calculi support the use of lithotripsy particularly for stones <100 mm(2). Treatment efficacy was not significantly different among stones localized in proximal and distal ureters. Degree of obstruction did not affect the ESWL outcomes in the proximal ureter, but it adversely affected SFR in the distal ureter.