Instillation of mitomycin C after transurethral resection of bladder cancer impairs wound healing: an animal model.

BACKGROUND Mitomycin C is used in the immediate post-operative period to prevent tumor re-implantation, but it has adverse effects on the bladder. This study devised an animal model to investigate the effects of intravesical mitomycin C on wound healing. METHODS AND MATERIALS A cystotomy was made in the dome of the bladder of female rats. The mucosa of the posterior wall was scratch with closed forceps. The bladder was closed and 0.2 ml of saline with or without 0.4 mg mitomycin C was instilled into the bladder transurethrally. The rats were sacrificed 30 and 60 days after the treatment and the bladder was examined grossly and microscopically. RESULTS The most frequent histological findings in the bladder were chronic inflammation and fibrosis. Fibrosis but not chronic inflammation was significantly associated with the exposure to MMC and it persisted even 60 days after the exposure to mitomycin C. CONCLUSION Mitomycin C produces chronic fibrosis in rat bladder that is often seen in patients receiving prophylactic treatment with this drug.