MP22-16 MULTI-INSTITUTIONAL ANALYSIS OF PERIOPERATIVE FACTORS ASSOCIATED WITH FAILED PRIMARY URETEROSCOPY WITHOUT PRIOR URETERAL STENTING

Abstract

INTRODUCTION AND OBJECTIVE: Ureteroscopy (URS) for treatment of nephrolithiasis is often attempted without a prior ureteral stent placement. When access to the stone fails, ureteral stenting is required for passive ureteral dilation in anticipation of a repeat URS in the future. In this study, we perform a multicenter analysis to identify patient or stone factors associated with failed unstented primary ureteroscopy (FURS). METHODS: We reviewed all primary URS for nephrolithiasis without prior ureteral stenting, performed at two institutions, Rush University Medical Center, Chicago (2007-2016) and Washington University School of Medicine, St. Louis (2016). Variables of interest in predicting failed primary URS include patient characteristics, stone characteristics, and prior stone surgery. Multivariate analysis was performed to identify significant factors associated with FURS. RESULTS: Failure rate for accessing the unstented ureter was 6.3% (40/634). Comparing successful URS (SURS) to FURS there was no difference in patient sex (p = 0.33) or age (0.69). Having a prior stone surgery including PCNL (p = 0.71), ESWL (p = 0.41), and URS (p = 0.57) was not associated with a FURS. Stone laterality and total stone burden (mean 9.5 mm vs 9.1 mm respectively) were similar between SURS and FURS. The number of stones at the time of URS also did not predict likelihood of URS failure (0.18). CONCLUSIONS: Failure of accessing stone during primary ureteroscopy can be hard to predict, but occurs in 6.3% of the time in our multi-institutional analysis. Having a prior stone surgery including PCNL, ESWL and URS does not affect the risk of having an unsuccessful primary ureteroscopy. Source of Funding: none