Urethroplasty Using Autologous Urethral Tissue-embedded Acellular Porcine Bladder Submucosa Matrix Grafts for the Management of Long-Segment Urethral Stricture in a Rabbit Model

ABSTRACT

We conducted this study to evaluate the combined effect of acellular bladder submucosa matrix (BSM) and autologous urethral tissue for the treatment of long segment urethral stricture in a rabbit model. To prepare the BSM, porcine bladder submucosa was processed, decellularized, configured into a sheet-like shape, and sterilized. Twenty rabbits were randomized to normal control, urethral stricture, urethroplasty using BSM only or BSM/autologous urethral tissue (n=5 per group). Retrograde urethrography was performed at 4, 8, and 12 weeks postoperatively, and the grafted specimens were harvested at week 12 to evaluate urethral reconstruction through histopathologic and immunohistochemical analysis. The mean urethral width of the control, stricture, BSM, and BSM/autologous urethral tissue groups at week 12 was 10.3+/-0.80, 3.8+/-1.35, 8.8+/-0.84, and 9.1+/-1.14 mm, respectively. The histopathologic study revealed that the BSM/autologous urethral tissue graft had a normal area of urethral lumen, compact muscular layers, complete epithelialization, and progressive infiltration by vessels in the regenerated urethra. In contrast, the BSM grafts revealed keratinized epithelium, abundant collagenized fibrous connective tissue, and were devoid of bundles of circular smooth muscle. Nontransected ventral onlay-augmented urethroplasty using an acellular BSM scaffold combined with an autologous urethral tissue graft represents a feasible procedure for urethral reconstruction.