Predictive Factors for Intraoperative Balloon Dilation in Semirigid Ureteroscopic Lithotripsy

Purpose: To analyze preoperative predictive factors for intraoperative balloon dilation in semirigid ureteroscopic lithotripsy. Patients and Methods: We retrospectively reviewed data from 397 consecutive semirigid ureteroscopic lithotripsies performed in 389 patients with ureteral stones at our institution during the calendar year 2010. Preoperative patient-related variables (age, sex, body mass index, history of urinary tract infection, previous stent placement, and time from initial presentation to intervention) and stone-related variables (laterality, numbers, location, width, and degree of hydronephrosis) were collected. Univariate analysis and multivariate logistic regression were performed to examine the statistical association between these variables and the use of intraoperative balloon ureteral dilation. Results: Intraoperative balloon dilation was performed in 109 (27.5%) procedures. Univariate analysis identified increasing stone width (P < 0.001) and lack of previous stent placement (P < 0.001) as preoperative predictors of intraoperative balloon dilation. Stone width (P < 0.001, odds ratio [OR] 1.274, 95% confidence interval [CI] 1.147-1.415) and lack of previous stent placement (P < 0.001, OR 0.025, CI 0.006-0.105) remained independently associated with intraoperative balloon dilation in multivariate logistic regression. Conclusions: To our knowledge, our study is the first to statistically analyze the potential predictive factors for intraoperative balloon dilation in semirigid ureteroscopic lithotripsy. Larger stone width was significantly associated with intraoperative balloon dilation, whereas the presence of an indwelling ureteral stent, for at least 1 week, nearly eliminated the need for balloon dilation in subsequent ureteroscopic lithotripsy.