Newly diagnosed contralateral reflux after successful unilateral endoscopic correction: Is it due to the pop-off mechanism?

Purpose: Our aim was to analyze the incidence of newly diagnosed contralateral vesicoureteral reflux after successful endoscopic correction of unilateral reflux by subureteral Teflon (polytetrafluoroethylene) injection and to explain the possible mechanisms responsible for new contralateral reflux. Materials and Methods: A total of 1,195 children underwent successful endoscopic correction of high grade primary and duplex grades III to V vesicoureteral reflux by subureteral polytetrafluoroethylene injection. Unilateral and bilateral reflux was noted in 495 and 700 children, respectively. The 495 cases of unilateral reflux were retrospectively analyzed for new contralateral reflux. Voiding cystourethrography was performed in all cases 3 months and 1 year after injection. Results: New contralateral reflux was diagnosed in 37 children (7%), including reflux in a single system in 33 and into a lower pole of a completely duplicated system in 4. There was no correlation of grade of ipsilateral reflux with the subsequent development of new contralateral reflux. No abnormality of the contralateral ureteral orifice was identified at initial cystoscopy, except for laterally placed ureteral orifices in 2 patients. Conclusions: The low incidence of new contralateral vesicoureteral reflux diagnosed after subureteral polytetrafluoroethylene injection versus open ureteral reimplantation may be due to noninterference with the contralateral trigone in endoscopic correction. The risk of new contralateral reflux did not increase with reflux severity (grades TV and V), suggesting that the pop-off mechanism is unlikely to be the cause of contralateral reflux.