Flexible ureterorenoscopy is associated with less stone recurrence rates over Shockwave lithotripsy in the management of 10-20 millimeter lower pole renal stone: medium follow-up results

PURPOSE: To identify the role of shock wave lithotripsy (SWL) and flexible ureterorenoscopy (f-URS) on the stone recurrence, in the management of 10-20 millimeter lower pole stone (LPS) with medium follow-up outcomes. MATERIALS AND METHODS: The patients’ charts which were treated with SWL or f-URS for LPS between January 2011 and September 2013 were analyzed, retrospectively. Patients who had a solitary 10-20mm LPS were enrolled into the study. In both procedures, patient was accepted as stone free, if complete stone clearance was achieved in the 3rd month abdominal computed tomography. Only patients with a stone free status were evaluated in follow ups. RESULTS: The stone-free rate was 77.9% (88/113 patients) for the SWL group and 89% (114/128 patients) for the f-URS group (p=0.029). Stone recurrence was detected in 28 (35.4%) patients in SWL group and in 17 (17.2%) patients in f-URS group (p=0.009). Stone types and 24 hour urine sample results were similar between groups (p=0.123 vs p=0.197, respectively). Multivariate regression analysis revealed that f-URS procedure and absence of abnormality in 24 hour urine analysis significantly decreased stone recurrence in medium term follow-up (p=0.001 and p<0.001, respectively). CONCLUSIONS: Our study showed for the first time, that patients which underwent f-URS for LPS, faced less stone recurrence, independent from diet regimen and metabolic evaluation in medium term follow-up. Additionally, presence of abnormality in 24 hour urine analysis increase the stone recurrence risk in follow-ups.