Login to Access Video or Poster Abstract: MP36-02
Sources of Funding: none

Introduction

To investigate the feasibility of urethral reconstruction using xenogeneic acellular dermal matrix graft (ADMG) seeded with autologous urothelial cells in a canine preclinical model.

Methods

Autologous bladder epithelia obtained from 4 male dogs were cultured, expanded and seeded onto preconfigured acellular dermal matrix graft (ADMG) to construct tis-sue-engineered urethras. A 3-cm segment of anterior urethra was removed in 8 adult male canines. Urethroplasties were performed using ADMG seeded with urothelial cells in 4 animals in experimental group and with ADMG without cells in other 4 animals in the comparison group. Retrograde urethrography was performed at 6 months after surgery. Two animals were scarified from each group at 3, 6 months and grafts were harvested. We assessed the repairing effects by Hematoxylin and eosin (H&E), Masson's trichrome and immunohistochemistry staining.

Results

The expanded urothelial cells showed good attachment to the ADMG. Canines in the experimental group survived until sacrifice. Urethrography after 6 months of gafting showed wide-caliber urethras without any sign of strictures. In contrast, urinary fistula occurred in 1 dog in the control group after 8 days of surgery, and other canines in this group also suffered from varying degrees of dysuria. Histologically, an epithelial cell layer surrounded by muscle fiber bundles was observed on the cell-seeded constructs at both 3 and 6 months postoperatively. In the control group, no urothelium or muscle could be detected at 3 months postoperatively. 6 months after surgery, formation of an epithelial cell layer occurred in the unseeded constructs, but with disorder structure in some regions and fewer muscle fibers. Furthermore, obvious scaring appears in two canines in this group, which might be attributed to severe inflammation and hyper-fibrosis. The epithelial and smooth muscle phenotypes were confirmed with antibodies to pancytokeratins AE1/AE3 and smooth muscle–specific desmin.

Conclusions

ADMG seeded with autologous urothelial cells could be an alternative tissue-engineering material for urethra reconstruction.

Funding

none