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 replacements using bowel. If patients who have undergone colocystoplasty need treatment with cyclophosphamide before or after the operation, does hemorrhagic cystitis develop? We evaluated the histological changes produced in the colon wall and bladder related to cyclophosphamide and its derivatives in rats that underwent colocystoplasty. Materials and Methods: Sprague-Dawley rats of each sex were grouped according 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 gross appearance of the bladder and colon segment used for colocystoplasty, and by histological changes. Results: Two weeks after surgery colocystoplasty had not resulted in secondary changes in the implanted colon segment or original bladder, while there were only nonspecific changes of an inflammatory type in the anastomotic area. After cyclophosphamide administration the animals lost considerable weight and in the bladder area we observed hemorrhagic cystitis that was greater in males than in females, and greater in isolated bladder than when the bladder was sutured to the colon segment. In the colon there was no inflammation or hemorrhage damage of the hemorrhagic cystitis type in the bladder. A total of 12 days after colocystoplasty there were no secondary histological changes except in the anastomotic area. A single 200 mg./kg. dose of cyclophosphamide caused substantial weight loss and hemorrhagic cystitis. Cystitis was quantitatively greater in males than in females and greater in isolated bladder than in bladder anastomosed to the colon. Conclusions: Administering a single dose of cyclophosphamide did not result in lesions in the colon segment used for colocystoplasty analogous to those of the bladder, such as hemorrhagic cystitis.