MP54-20 ACCURACY OF ULTRASONOGRAPHY FOR THE EVALUATION OF UROLITHIASIS IN PATIENTS UNDERGOING EXTRACORPOREAL SHOCKWAVE LITHOTRIPSY: COMPARISON WITH NON-CONTRAST COMPUTED TOMOGRAPHY

Abstract

INTRODUCTION AND OBJECTIVES: percutaneous nephrolithotomy (PNL) is the preferred treatment of high dense renal stones. In this study we tried to compare the outcomes of PNL versus shock wave lithotripsy (SWL) for high density (1000-1500 HU on non-contrast computed tomography [NCCT]) moderate sized (1025mm) renal calculi as regards stone-free rate and procedure morbidity. METHODS: A prospective study was conducted in our department from March 2012 to May 2014. Eighty consecutive patients; excluding lower calyceal stones; were randomized to receive either PNL or SWL (40 in each arm). Patients were followed-up by abdominal ultrasound and plain X-Ray (NCCT if indicated) till clearance of stone. Outcomes, complications (the modified Clavien system), costs, and SF8 Health Survey scoring were recorded for each group. Median followup was 8 months (range 6 to 30). RESULTS: Basic characteristics of both groups were comparable. After single treatment session, 3-week success rates were 80 and 27.5% for PNL and SWL respectively (p < 0.001). Overall 3-month stone free rates after PNL and SWL monotherapy were 87.5 vs. 90%, respectively (p 1⁄4 0.723). Median number of required maneuvers till stone clearance was one (range 1-3) for PNL vs. two (range 1-4) for SWL (p < 0.001). The complication rates for the PNL and SWL were 10 and 7.5%, respectively (p 1⁄4 0.692). SWL was done as outpatient procedure while median hospitalization time per patient was 2 days (range 2-6) in the PNL group. The cost of SWL was significantly lower (p < 0.001). Patient-reported outcomes, including overall physical and mental health status, were comparable for both PNL and SWL. On multivariate analysis, single renal stone was an independent predictor for complete stone clearance after 2 sessions of SWL (OR 7.26, 95% CI 1.1346.62, p1⁄40.037). CONCLUSIONS: For treatment of moderate-sized high density renal stones, PNL provides significantly higher initial success and lower retreatment rates compared with SWL. Although PNL is effective, it has some limitations including invasiveness and cost. SWL is another alternative especially for single moderate-sized high density renal stone.