Histopathological evaluation of the urethra after the Snodgrass operation: an experimental study in rabbits

Abstract

OBJECTIVE: To investigate the histopathological outcome of the incised urethral plate after tubularized incised-plate urethroplasty (the Snodgrass procedure to repair hypospadias) in a hypospadiac rabbit model, as it can produce meatal and neourethral strictures, and healing with scarring. MATERIALS AND METHODS: The study comprised 10 male New Zealand White rabbits (2.2-2.4 kg); under general anaesthesia the ventral urethra was completely excised 1 cm from the meatus proximally and a model of hypospadias formed. A full-thickness incision was then made in the distal dorsal urethra and the two sides of the incision marked by Indian ink tattooing. After placing a feeding tube (5 F) as a urethral catheter, both urethral wings were sutured ventrally by a 7/0 polydioxanone running suture, and the penile skin approximated by 5/0 chromic catgut. At 21 days and 3 months after surgery the penises were harvested, assessed histopathologically, and compared with those from control untreated rabbits of the same age and weight. RESULTS: In the study group the incised area of the dorsal urethra was re-epithelialized; the regional tissue and vascularity were normal. CONCLUSION: In this rabbit model the dorsal urethral incisions healed with no scar tissue; only the ventral suture lines had minimal fibrosis and inflammatory reaction.