Abstract
PURPOSE: Urine leakage (UL) is a recognized complication after partial nephrectomy (PN). This study aimed to determine the incidence of UL and identify key risk factors, including tumor size and surgical approach, to clarify the impact of robotic-assisted, laparoscopic, and open PN on postoperative outcomes. METHODS: A retrospective review of 785 consecutive clinical T1 PN cases (2012-2022) was undertaken. UL was defined as biochemically confirmed uriniferous drain output ≥ 50 mL day-1 persisting ≥ 3 days. The overall incidence of UL was assessed, and multivariable statistical tests evaluated potential predictors of leakage. (19 events; EPV = 3.8; hypothesisgenerating). RESULTS: Of the 785 patients, 50.7% had RAPN, 33.8% OPN, and 15.5% LPN. The overall incidence of UL was 2.4%. RAPN demonstrated the lowest leakage rate (0.75%), compared with OPN (3.7%) and LPN (4.91%) (p = 0.03), representing a five-fold reduction in UL risk compared to open and laparoscopic approaches. Patients with T1b tumors were significantly more prone to leakage than those with T1a tumors (15.8% vs. 0.99%; multivariable odds ratio (OR) = 18.8, 95% CI = 7.15-49.44; p < 0.0001). Longer operative and ischemia times were also associated with higher leakage risk. All UL cases resolved with conservative or minimally invasive interventions. CONCLUSIONS: Surgical approach, operative duration, ischemia time, and tumor size (T1b vs. T1a) emerged as principal predictors of postoperative UL. RAPN conferred a notably lower leakage risk compared to OPN and LPN, underscoring its advantages for nephron-sparing surgery, particularly in complex renal tumors requiring meticulous collecting-system closure. TRIAL REGISTRATION: Not applicable (retrospective).