Cyclophosphamide-induced hemorrhagic cystitis in rats that underwent colocystoplasty: Experimental study

Purpose: Cyclophosphamide and its derivatives induce hemorrhagic cystitis. A substantial number of patients receive bladder augmentation or replacemen ts using bowel. If patients who have undergone colocystoplasty need treatme nt with cyclophosphamide before or after the operation, does hemorrhagic cy stitis develop? We evaluated the histological changes produced in the colon wall and bladder related to cyclophosphamide and its derivatives in rats t hat underwent colocystoplasty. Materials and Methods: Sprague-Dawley rats of each sex were grouped accordi ng to whether they received a single 200 mg./kg. dose of cyclophosphamide, underwent colocystoplasty, underwent each technique or served as controls. The technique of colocystoplasty was the same in all groups. Results were analyzed according to previously reported criteria, by the gro ss appearance of the bladder and colon segment used for colocystoplasty, an d by histological changes. Results: Two weeks after surgery colocystoplasty had not resulted in secondary changes in the implanted colon segment or or iginal bladder, while there were only nonspecific changes of an inflammator y type in the anastomotic area. After cyclophosphamide administration the a nimals lost considerable weight and in the bladder area we observed hemorrh agic cystitis that was greater in males than in females, and greater in iso lated bladder than when the bladder was sutured to the colon segment. In th e colon there was no inflammation or hemorrhage damage of the hemorrhagic c ystitis type in the bladder. A total of 12 days after colocystoplasty there were no secondary histological changes except in the anastomotic area. A s ingle 200 mg./kg. dose of cyclophosphamide caused substantial weight loss a nd hemorrhagic cystitis. Cystitis was quantitatively greater in males than in females and greater in isolated bladder than in bladder anastomosed to t he colon. Conclusions: Administering a single dose of cyclophosphamide did not result in lesions in the colon segment used for colocystoplasty analogous to thos e of the bladder, such as hemorrhagic cystitis.