Volume capacity and pressure characteristics of the continent ileal reservoir used for urinary diversion.

The volume capacity and the pressure characteristics of the continent ileal reservoir for urinary diversion were studied at specific intervals postoperatively in 26 patients. The reservoir volume increased during the first year postoperatively from approximately 100 ml. at operation to a mean of 735 ml. and then remained stable during an observation period of up to 7 years. The basal pressure increased during filling from 0 to about 10 cm. water. During physiological conditions, that is when the reservoir was filled by diuresis, the basal pressure was equal to those pressures measured during saline infusion at corresponding reservoir volumes. Calculation of the magnitude of motor activity by 2 different methods showed a significant decrease in activity at 12 months compared to at 2 months after construction of the reservoir. Data from the continent urostomy reservoir were compared to corresponding data from the continent ileostomy and cecal reservoirs for fecal diversion, these being obtained in previous studies in our laboratory. The ileal reservoirs used for fecal or urinary diversion were practically identical with regard to volume capacity, basal pressure and motor activity. However, the cecal reservoir had a significantly lower volume capacity and higher basal pressure at corresponding reservoir volumes, while the motor activity was approximately 10 times greater than in the ileal reservoir. The results indicate that with regard to volume capacity and pressure characteristics the ileal reservoir is superior to the cecal reservoir as a receptacle for urine.