Is primary obstructive megaureter repair at risk for contralateral reflux?

Purpose: Contralateral vesicoureteral reflux occurs after successful unilateral reflux repair in a significant proportion of patients without correlation to the surgical approach. Unilateral congenital obstructive megaureter was compared to primary vesicoureteral reflux with regard to the risk of onset of contralateral reflux after unilateral ureteral reimplantation. Materials and Methods: Unilateral congenital obstructive megaureter was diagnosed in 58 consecutive patients 2 to 10 years old (mean age 3.2). Cross-trigonal ureteroneocystostomy was performed in 57 cases and longitudinal ureteral reimplantation, according to the Politano-Leadbetter technique was done in 1. Longitudinal tapering according to Hendren was performed in 44 ureters, and the Kalicinski folding was used to repair 11 ureters. All patients underwent serial renal ultrasound, diethylenetetraminepentaacetic acid nuclear scan, excretory urogram and voiding cystourethrogram. The control group was composed of 98 age matched children with unilateral vesicoureteral reflux who underwent unilateral reimplantation with or without tapering. Fisher's exact test and Student's t test were used for statistical analysis. Results: Followup ranged from 1 to 5 years. All patients in both groups underwent a voiding cystourethrogram at 6 months, and renal ultrasound at 3, 6 and 12 months postoperatively. Grade 2 reflux developed in 1 study group patient after contralateral Kalicinski ureteral folding and cross-trigonal reimplantation (1.7%;). In the control group new onset contralateral reflux developed in 11 cases (11.2%). The difference was statistically significant (p <0.005, Fisher's exact test p = 0.033). Conclusions: Ureteral reimplantation for unilateral congenital obstructive megaureter is not correlated with the development of contralateral reflux. The occurrence of contralateral reflux after successful unilateral reflux repair is high (11.2%), and is not correlated with age, sex and technique of reimplantation or tapering. These results support the hypothesis that the functional anatomy of the trigone is preserved in congenital obstructive megaureter but is impaired on both sides in cases of unilateral vesicoureteral reflux. The surgical management of unilateral primary vesicoureteral reflux and congenital obstructive megaureter should be differentiated based on these results.