Urethral duplication with unusual cause of bladder outlet obstruction.

A 12-year-old boy presented with poor flow and recurrent urinary tract infections following hypospadias repair at the age of 3 years. The evaluation revealed urethral duplication with a hypoplastic dorsal urethra and patent ventral urethra. He also had duplication of the bladder neck, and on voiding cystourethrogram the ventral bladder neck appeared hypoplastic and compressed by the dorsal bladder neck during voiding. The possibility of functional obstruction of the ventral urethra by the occluded dorsal urethra was suspected, and he underwent a successful urethro-urethrostomy.