Outcome of Extracorporeal Shock Wave Lithotripsy in Patients with Multiple Renal Calculi Based on Stone Burden and Location

Abstract

Of 2,234 renal units treated with the Dornier HM₃ lithotripter, 641 contained multiple renal calculi. The number of treatments/kidney ratio varied from 1.0 to 1.58 (mean = 1.47) and was dependent on stone burden and location.

Radiological follow-up on 525 renal units (81%) after 3 to 42 months (mean = 7.5 months) showed 54.1 % were stone free, 21.5% had residual stone fragments (≤ 4 mm), and 24.4% had residual fragments > 4 mm. A significant difference in stone-free efficacy was demonstrated between stones ≤ 15 mm and > 15 mm (p < 0.001 ) and < 30 mm and ≥30 mm (p < 0.001). Patients with multiple renal calculi < 15 mm became stone free in 72% of cases compared to 40% of cases with a stone burden ≥ 30 mm.

Stone-free efficacy was also influenced by stone site but did not reach statistical significance. Complications occurred in 49 renal units (9.3%) and was unrelated to stone burden. New stone formation occurred in 18 cases (3.4%). The presence of multiple renal calculi had an adverse effect on stone-free outcome.