Defunctionalized bladders: effects before and after refunctionalization in an animal model.

PURPOSE

Bladder behavior after refunctionalization is usually unpredictable. We comparatively analyze various aspects of bladder defunctionalization and subsequent refunctionalization using an animal model.

MATERIALS AND METHODS

A total of 18 rabbits were divided equally into 3 groups. Animals in group 1 underwent 2 successive surgical procedures, including bladder division and reattachment. Bladder division was performed by hemisecting the bladder from dome to trigone into a functioning and nonfunctioning chamber. Bladder reattachment was achieved by reanastomosing both hemibladders. Group 2 animals underwent sham operations, and group 3 animals were age matched normal controls. Serial urodynamic studies and fluoroscopic cystograms were performed in all animals. Gross, histochemical (hematoxylin and eosin, Masson's trichrome and Sirius red) and immunocytochemical (alpha-actin, collagen I and III) analyses, collagen content determination and organ bath studies were performed.

RESULTS

The defunctionalized hemibladders demonstrated lower wet weight, capacity and compliance compared to the functional contralateral and normal control bladders. Refunctionalization of the bladders resulted in a progressive recovery of capacity and compliance with time. The bladder contractile response and connective tissue-to-muscle ratio were abnormal in the defunctionalized segments but normalized after bladder refunctionalization.

CONCLUSIONS

Defunctionalization results in remarkable alterations in bladder growth, capacity, compliance and distribution of connective tissue. However, these bladders demonstrate an innate capacity to recover from these alterations following refunctionalization.