Urethral reconstruction using autologous and everted vein graft: an experimental study.

Urethral reconstruction is one of the problematic issues in pediatric surgery. To evaluate the efficacy of vein graft for urethral reconstruction in rabbits, about 3 cm of distal urethra was excised under microscopic magnification. In groups A, B, and D, the urethra was replaced with the internal jugular vein. In group B, before performing anastomosis, vein grafts were everted. In group C (control group) after removing the urethra, a catheter was inserted without substituting the urethra and then fixed. Groups A, B, and C were kept for 3 months. Group D was divided into five subgroups each consists of two rabbits, which were killed at days 7, 10, 14, 22, and 30 for evolutionary histopathological studies. Gross evaluation, retrograde urethrography, and histopathological studies were also performed in other groups. Retrograde urethrography and gross evaluation revealed no sign of stricture and fistula formation in six and eight rabbits in groups A and B, respectively. However, those complications were observed in all the rabbits in group C. The grafted part of the neourethra was epithelialized with uroepithelium in all rabbits in group A (vein graft) and group B (everted vein graft) but only partial epithelialization was observed in three rabbits of group C. Severe fibrosis with stricture formation was developed in six rabbits in the control group. In group D, epithelialization gradually replaced necrosis and inflammation, within 1 month. This study showed that vein, everted or not, can be used as a substitute for urethra. It also suggests that new epithelialization might be formed from ingrowing of the uroepithelium from the proximal part.