Objective: To evaluate the result of urethral defect repair using freeze-dried acellular bladder submucosa.
Methods: The freeze-dried acellular bladder submucosa was obtained from human cadaveric bladder submucosa using freeze-thawed enzymatic treatment and the freeze-drying technique. 18 male New Zealand rabbits were used in this experiment. A defect of 1.0 cm x 0.5 cm was created in the ventral urethra of the animal. The acellular matrix was grafted to the urethral defect in 14 rabbits. The other 4 animals underwent a sham operation as the controls. From postoperative one to twenty-four weeks, the animals underwent retrograde urethrography at certain intervals. The grafts of the acellular matrix were taken and prepared for histological evaluation.
Results: No obvious urethral stricture was observed in the 14 matrix-grafted animals. Histological examinations of the specimens showed progressive infiltration of cells and vascular vessels. Complete epithelization was obtained at 2 weeks. The orientation of collagen fibers in the matrix-grafted area tended to be regular with time.
Conclusions: Freeze-dried acellular bladder submucosa may be a suitable material for urethral defect repair, which induces urethral mucous cells to migrate, grow and epithelialize.