Ectopic ureters in anorectal malformations.

Purpose: The literature about ectopic ureters in anorectal malformations is limited. Repair of an anorectal malformation may require dissection near the normal or abnormal insertion of the ureters. Knowledge of the presence and location of ectopic ureters may prevent intraoperative injury. We aim to describe the incidence and location of ectopic ureters in patients with anorectal malformations and to characterize associated renal anomalies.

Methods: This is an IRB-approved retrospective study of patients with anorectal malformations and ectopic ureters identified in our colorectal database.

Results: Of 2283 patients with anorectal malformation, 79 (3.5%) had ectopic ureter(s). Of those, 29% had bilateral ectopic ureters. Nearly all (87%) of bilateral ectopic ureters occurred in females. Ectopic ureters most commonly inserted into the bladder neck (33%), vagina (15%), or urethra (13%). Renal dysfunction was noted in a high proportion of patients. The majority (59%) of ectopic ureters were associated with dysfunction of the ipsilateral kidney. Interestingly, 29% of patients with unilateral ureteral ectopia had an abnormal contralateral kidney. Only 22 patients (28%) had two normal kidneys, and 5 (6%) had documented renal failure with 2 (2.5%) requiring renal transplant. This compares to a transplant rate of 0.6% among anorectal malformation patients without ectopic ureter.

Conclusions: The incidence of ectopic ureter is 3.5% among anorectal malformation patients. Cloaca and recto-bladder neck fistula are the types of anorectal malformation with higher incidence. Ureteral ectopia seems to confer an increased risk of renal failure. Identifying ectopic ureters is important for surgical planning and monitoring renal function vigilantly.