Outcome of extracorporeal shockwave lithotripsy monotherapy for large renal calculi: effect of stone and collecting system surface areas and cost-effectiveness of treatment.

The treatment options for large renal calculi are controversial. We report on our experience with 65 treatments of renal calculi > 3 cm using extracorporeal shockwave lithotripsy (SWL) monotherapy. We stratified our results according to stone and collecting system surface areas (measured by computer image analyses), stone location, and stone type. The overall success rate of SWL monotherapy was 27% at 3 months. The best stone-free rate (60%) was obtained for stones < 500 mm2 and located primarily within the renal pelvis. The stone-free rate for stones with surface areas > 1000 mm2 was only 8%. None of the cystine stones was treated successfully, whereas 80% of patients with uric acid stones became stone free. We estimated an average cost of $67,048 to render a patient with a large renal calculus stone free using SWL monotherapy. We recommend that other treatment options, such as percutaneous nephrolithotomy, be considered as first-line therapy for large renal calculi.