Duplication of the urethra.

Ten patients with patent urethral duplication are presented. Nine patients had two independent patient channels originating from the bladder or the posterior urethra. Both voiding cystourethro and retrograde urethrography are necessary to completely evaluate this anomaly. In each instance the ventral channel, regardless of the position of its meatus, proved to be the more functional urethra. In those patients whose dorsal channel was in an epispadiac position, the symphysis pubis was abnormally wide. A functionally and anatomically accurate classification is proposed, and the embryology of these anomalies is discussed.