Urinary bladder wall substitution using autologous tunica vaginalis in male dogs.

Fresh autologous tunica vaginalis was experimentally used for partial substitution of the excised urinary bladder wall in ten male mongrel dogs. The substituted areas of two dogs were examined macroscopically and histologically at 2, 4, 6, 8, and 10 weeks after surgery. Two control dogs underwent partial cystectomy and primary wall closure without substitution. The regenerated transitional epithelium completely covered the substituted portion and smooth muscle regeneration was present at 6 weeks. The bladder walls at the closure area of one control dog and at the substituted portions of two dogs at 10 weeks were indistinguishable macroscopically from the native bladder with all layers of the bladder wall present histologically. According to the macroscopic and histological findings and simplicity of the technique, tunica vaginalis can be used as an alternative graft for bladder wall substitution. Calcification and bone metaplasia observed were similar to those found after using other tissue grafts.