New contralateral vesicoureteral reflux after unilateral ureteral reimplantation: predictive factors and clinical outcomes.

PURPOSE: Although unilateral ureteral reimplantation for vesicoureteral reflux is highly successful, new contralateral reflux will develop postoperatively in some patients. We examined predictors and clinical outcomes of postoperative contralateral vesicoureteral reflux. MATERIALS AND METHODS: We reviewed patients who underwent nontapered unilateral reimplantation for primary vesicoureteral reflux graded on a 3-point scale at our institution from January 1990 to December 2002, and identified those with subsequent contralateral vesicoureteral reflux. We analyzed the association of patient/procedure characteristics with incidence, and time to resolution of contralateral reflux and postoperative urinary tract infection. Multivariable models controlled for variables associated with incidence and time to resolution of contralateral reflux. RESULTS: A total of 395 patients (77.2% female, median age 5.3 years) underwent ureteral reimplantation for vesicoureteral reflux. Preoperative reflux was grade 1 in 2.8% of patients, grade 2 in 56.6% and grade 3 in 40.6%. Technical success was 95.4%. After reimplantation 39 patients (9.9%) had new contralateral reflux (grade 1 in 7, grade 2 in 27 and grade 3 in 5). Median followup was 51.8 months. On multivariate analysis younger age (less than 6 years, OR 3.7, p = 0.006) and low observed bladder capacity as percent of predicted bladder capacity (less than 50% of predicted capacity, OR 6.3, p = 0.02) were significant predictors of contralateral reflux. Contralateral reflux resolved in 21 of 27 patients (77.8%) on subsequent cystography at a median of 21.5 months. Two patients underwent reimplantation for persistent contralateral reflux. Four of 39 patients (10.3%) with contralateral reflux had postoperative febrile urinary tract infections at a median of 26 months, with spontaneous resolution of contralateral reflux in all. CONCLUSIONS: Younger patients and those with low observed vs predicted bladder capacity may be at increased risk for postoperative contralateral vesicoureteral reflux. A majority of contralateral reflux will resolve spontaneously, and the clinical course is typically benign.