Tubularized urethral replacement using tissue-engineered peritoneum-like tissue in a rabbit model.

INTRODUCTION

This study aims to investigate whether mesothelial cells could function as seed cells to construct tissue-engineered peritoneum-like tissue for urethral reconstruction in a rabbit model.

MATERIALS AND METHODS

Bladder acellular matrices were prepared and trimmed to 1.5 × 1 cm. Nine male rabbits underwent omentum biopsy and autologous mesothelial cells were isolated. After in vitro expansion, the cells were seeded onto the matrices and incubated for 7 days. In 18 rabbits, a pendulous urethral segment 1.5 cm long was totally excised and urethroplasty was performed with tubularized matrices seeded with cells in 9 animals and without cells in 9 as controls. Urethrography was performed at 1, 2 and 6 months postoperatively. Meanwhile, the neourethras were harvested and analyzed grossly and histologically.

RESULTS

Histological analysis of the cell-seeded grafts revealed a loose collagen matrix covered with a single layer of mesothelim. Serial urethrography indicated a wide urethral caliber without stricture formation in animals implanted with cell-seeded matrices, while all animals of the control group developed stricture. Histological analysis of the implanted cell-seeded matrices demonstrated a normal urethral architecture by 1 month, composed of multilayers of urothelium surrounded by smooth muscle bundles, which became increasingly organized with time. By 6 months, the neourethra could be hardly distinguished from native urethra both grossly and histologically.

CONCLUSIONS

Autologous mesothelial cells could be successfully used as seed cells for tubularized urethral reconstruction in male rabbits.