Stone recurrence after stone free status with extracorporeal shock wave lithotripsy

BACKGROUND: The objects of this study is to evaluate the ipsilateral stone recurrence who became stone free status after extracorporeal shock wave lithotripsy (ESWL). METHODS: Three hundred ninety five patients who became stone free after ESWL with Lithostar and followed more than 6 months, were analyzed stone recurrence. Stone recurrence were diagnosed by KUB and/or ultrasound. Actual recurrence free rate were calculated based on the period from the day of achieved stone free status to the day of estimated recurrence. Eight factors examined included sex, side, number, location, size, stone history urological complication, hydronephrosis and also contralateral recurrence was analyzed. RESULTS: Over all ipsilateral recurrence free rate were 96.5%, 78.8%, 65.3% after 1, 3 and 5 years, respectively. Contralateral stone free rate were 98.1%, 92.5%, 87.2% after 1, 3 and 5 years. Five-year recurrence free rate according stone factors, there were significant difference in stone number (Single 71.1% and multiple 31.6%), in stone history (with history 77.1% and without 35.7%), in urological complication (without complication 67.7% and with complication 35.7%). However, there were no significant difference in sex, side, stone, location, stone size and hydronephrosis. CONCLUSION: This results suggested that the stone number, stone history and urological complication were highly related to ipsilateral stone recurrence after stone free status by ESWL. Extracorporeal shock was lithotripsy had probability of higher stone recurrence rate.