Urethral healing in rabbits.

We studied urethral healing in New Zealand white rabbits by histological examination after insult (urethral catheter) or injury (urethrotomy) specifically for acute and chronic inflammation, fibrosis, fistulas, squamous metaplasia, foreign body giant cells and urethral dilatation. Urethral catheterization resulted in increased inflammation and fibrosis compared to noncatheterized animals. Skin closure techniques and materials resulted in an inflammatory response that may extend to and involve the urethra. Minor differences in suture size were not an important variable but the persistence of suture material may have a role in the degree of inflammation and the formation of foreign body giant cells. Transepithelial closure techniques drag epithelial cells into subcutaneous tissues and may predispose to fistula formation.