Incompetent urethral sphincter in a girl with a unilateral single ectopic ureter.

A rare case of an incompetent urethral sphincter associated with a unilateral single ectopic ureter is reported. Urinary incontinence persisted even after removal of a dysplastic kidney draining into the vagina. No neurological defect was found. Manual compression of the bladder elicited urine leakage from the urethra, and the urethral closure pressure was markedly low. Cystometry and voiding cystourethrography were normal. Continence was restored completely by a urethral sling operation.