Impact of ectopic insertion on treatment outcome of primary non-refluxing megaureter

Objective: To investigate the characteristics of primary non-refluxing megaureter with ectopic insertion and its effects on renal function. Methods: Of 118 patients diagnosed with primary non-refluxing megaureter, we retrospectively studied 33 patients who underwent surgical treatment. Depending on the position of ureteral insertion, patients were classified as having either an ectopic or orthotopic megaureter; clinical characteristics and renal function, were analyzed. Results: Among the 36 primary non-refluxing megaureters, 7 (19.4%) had ectopic megaureter. A total of 34.5% of the orthotopic megaureter and all ectopic megaureter cases were women (P =.003). The mean value of maximum ureteral diameter was significantly wider for ectopic than for orthotopic megaureter (16.3 vs 12.1 mm, respectively, P =.029). Mean preoperative differential renal function (DRF) were 36.4% and 43.0% for ectopic and orthotopic megaureters, respectively (P =.164). After surgery, the mean DRF of ectopic megaureter had decreased from 50% to 18.8%, whereas the mean DRF of orthotopic megaureter was 42.9% (P <.001). At the time of surgery, the mean age of patients was 4.6 months in the ectopic megaureter and 16.7 months in the orthotopic megaureter (P =.005). Conclusion: In our study, all the cases of an ectopic megaureter occurred in women, and the ureteral dilatation was comparatively more severe than in orthotopic megaureters. In addition, despite early surgical treatment, renal function deteriorated gradually. Further analyses are necessary to determine whether earlier surgical intervention for preventing deterioration of renal function is worthwhile or not.