Tubularized urethral reconstruction using everted saphenous vein graft in a beagle model

Background A long segment stricture in the anterior urethra is a challenge in urology. We conducted a study to investigate the efficacy of anterior urethral reconstruction using an everted saphenous vein graft (SVG) in a tubular fashion. Methods Twelve male beagles were randomly divided into three groups: experimental group (n = 5), control group (n = 5) and normal group (n = 2). A 3 cm defect in the anterior urethra was created. Autologous SVG was harvested. In the experimental group, urethral defect was replaced by an everted SVG in a tubular fashion. In the control group, urethral reconstruction was performed using an uneverted SVG. Beagles in all groups received retrograde urethrography to evaluate urethral patency and were killed for histological examination 6 months after operation. Results Four beagles in the experimental group had no voiding difficulty and the other one could not void spontaneously. Retrograde urethrography showed the four beagles in experimental group had wide urethral lumens. Ether urethral stricture or fistula were detected in all animals in the control group. Histological analysis of the four beagles in the experimental group indicated the everted SVG completely integrated into the urethra. The reconstructed urethra contained a wide lumen and was completely covered by urothelium. The periurethral collagen and muscle fibers formed and were highly organized. Everted SVG showed a high ability of neovascularization. In the control group, the reconstructed segment showed a fibrotic urethral lumen where the urothelium was not intact. Only few new capillaries were formed. Conclusions Everted SVG demonstrates for a promising strategy for potential urethral stricture repair.