Progressive ureteral dilation for subsequent ureterocystoplasty.

PURPOSE

The complications associated with bladder augmentation using the gastrointestinal tract are well known. A bladder based ureteral flap is a viable alternative for augmentation. However, its use is limited to cases in which a dilated ureter is already present due to associated pathological conditions, such as reflux. We designed a system for performing progressive dilation in a normal ureter, which can subsequently be used for augmentation.

MATERIALS AND METHODS

Ten rabbits underwent unilateral ureteral ligation at the ureterovesical junction and ipsilateral nephrectomy. A silicone catheter was threaded into the proximal ipsilateral ureter and connected to an injection port, which was secured subcutaneously. Ten days to 2 weeks after surgery a saline-antibiotic solution was injected subcutaneously daily into the injection port. Cystography and cystometrography were performed with an accurate measurement of bladder capacity. Ureterography was done initially and then weekly by injecting contrast medium into the ureter. After ureteral dilation ureterocystoplasty was performed in each animal.

RESULTS

After 1 month of daily saline-antibiotic solution injections the ureteral units were dilated at least 10-fold, as measured by radiography. The dilated ureteral diameter exceeded that of adjacent colon in each instance. Augmentation cystoplasty was performed with the reconfigured dilated ureteral segment. Repeat cystography and cystometrography showed an average 260% increase in bladder capacity (range 190 to 380%).

CONCLUSIONS

Ureteral dilation can be accomplished using our system. At least a 10-fold increase in ureteral size is possible. The dilated ureteral segment can be used effectively for bladder augmentation, avoiding the use of bowel segments.