Long-Term Stone-Free Rates After Extracorporeal Shock Wave Lithotripsy

Abstract

One thousand three patients with upper urinary tract calculi were treated with extracorporeal shock wave lithotripsy (ESWL). On discharge, 35.2% of patients were stone free, 42.4% had residual fragments less than 3 mm, and 461 patients (46%) reported spontaneous passage of fragments mainly during the first three months after ESWL treatment.

All patients were reevaluated after a mean of 19.1 months. The overall stone-free rate was 72.3%. There was no difference between primary and recurrent stone formers. Lower calyceal stones had the worst stone-free rate (57.8%) and also suffered new stone growth in 58.4%. Almost identical results were obtained for stones other than in the lower pole calix when, on discharge, fragments were found in the lower pole calix. Multiple stones, especially when located in a dendritic collecting system, yielded a stone-free rate of 64% with about 90% of patients revealing regrowth of residual calculi. Stone analysis showed stone growth mainly occurred in carbonate apatite and struvite stones. Follow-up IVPs were normal in 97%. Readmission was necessary in 57 patients.

Overall, almost one-fourth of patients still had residual fragments after a mean follow-up of 19.1 months. Stone-free rates were mainly influenced by the primary stone location, the number of stones and the anatomy of the collecting system.