Clinical experience and results of ESWL treatment for 3093 urinary calculi with the Storz Modulith SL 20 lithotripter at the Singapore General Hospital

We study the outcome of 2700 patients treated for 3093 urinary calculi over a period of 60 months. All patients underwent Extracorporeal Shock Wave Lithotripsy ( ESWL) treatment using the Storz Modulith SL20, predominantly on an outpatient basis (99.9% using intravenous pethidine for analgesia). The treatment outcome of 1666 renal calculi and 1427 ureteric calculi were analysed and stratified according to size and site. Follow-up status at 3 months was available for 91.8% of patients. For renal calculi, the overall success rate was 81% ( re-treatment rate 29.7%). The majority of failures were stones larger than 2cm and those situated in the lower pole of the renal calyces. The overall success rate for ureteric calculi is 85% with similar clearance rates throughout the ureter (re-treatment rate 22.8%). Failures were predominantly with stones larger than 2cm. For the entire series, the morbidity rate requiring hospital admission was 2.9%, there was no mortality. The commonest cause for admission was for pain control (1.8%). To our knowledge, our experience with this lithotriptor is the largest to date. We have demonstrated that ESWL with Storz Modulith SL20 is safe, well tolerated and highly effective for the treatment of urolithiasis.