Nontransected Ventral Onlay-augmented Urethroplasty Using Autologous Saphenous Vein Graft in a Rabbit Model of Urethral Stricture

Abstract

To evaluate the efficacy and feasibility of nontransected ventral onlay-augmented urethroplasty using an autologous saphenous vein graft in a rabbit model of urethral stricture. Ten white male rabbits weighing 3.0-3.5 kg were selected, and a long tract urethral stricture was generated by excising an 0.8-cm wide and 2-cm long portion of the distal urethra. One month after the procedure, the rabbits were randomized into a urethral stricture group (n= 5) or urethroplasty with saphenous vein graft group (n= 5). Another 5 rabbits served as a normal control group. Retrograde urethrography was performed at 2, 4, 8, and 12 weeks after surgery in all groups, and the rabbits were killed at 12 weeks postoperatively for histopathologic and immunohistochemical evaluation. The mean operated urethral width of the normal, stricture, and vein graft group was 10.2 ± 0.84, 4.3 ± 0.97, and 10.04 ± 2.35mm at 2 weeks postoperatively, respectively (P= .008). The 4-, 8-, and 12-week postoperative urethrograms revealed results similar to those of the 2-week postoperative urethrograms. Histologic analysis showed the neourethra was epithelialized with urothelium in the vein graft group. All the rabbits survived throughout the study period without fistula formation or infection. Nontransected ventral onlay-augmented urethroplasty using an autologous saphenous vein graft can be an effective and feasible procedure for the surgical management of long tract urethral stricture.