Relative Microbial Resistance of Gastric, Ileal and Cecal Bladder Augmentation in the Rat

Purpose: Bladder resistance to bacterial infection after gastrocystoplasty and cecocystoplasty was investigated in the rat. Materials and Methods: Bladders were infected with Escherichia coli 6 to 13 months after augmentation and urine culture was obtained weekly for 3 months. Results: No differences were observed in the number of infected animals within each group or electrolyte data among groups. The number of animals infected after surgery but before E. coli challenge was lowest in the gastrocystoplasty group. Bladder stones formed only in ileocystoplasty and cecocystoplasty groups. No group had a change in urinary pH. Conclusions: Gastrocystoplasty may be associated with a lower incidence of spontaneous infection and stone formation. An aggressive infection protocol may have masked differences in susceptibility to infection. Since urinary pH was unchanged after gastrocystoplasty, use of the rat may not be appropriate for augmentation studies.