Prosthetic urinary bladder implantation to facilitate bladder regeneration

A temporary artificial bladder was implanted in 15 female dogs undergoing total or subtotal cystectomy. One or two months after implantation, the prosthesis was removed. In three dogs sacrificed 6 months after prosthesis implantation, a new urinary reservoir was identified. Two dogs failed to develop a urinary reservoir, and both ureters anastomosed directly to the top of a dilated urethra. Seven dogs died from complications (infection, urine leakage, etc). Three additional dogs are alive and well 2.5 months after implantation, and in these animals a new urinary reservoir has been demonstrated by cystography. Histologic examination of the new urinary reservoir revealed a thin lining of transitional cell-like epithelium and an underlying attenuated muscle layer. The ability of the canine species to generate a functioning urinary reservoir after total or subtotal cystectomy may hold promise for eventual clinical application in humans.     

Urinary bladder reformation: Regeneration or dilatation?

In an earlier study, urinary bladder regeneration was investigated. For that purpose, 15 dogs were subjected to total or subtotal cystectomy, and a silicone rubber prosthesis was nestled in the trigone and covered with polyglycolic acid mesh. After 3–5 months, a newly formed urinary reservoir was found in six dogs. Since transitional cell epithelium and smooth muscle were identified in the wall of the reservoir, it was concluded that bladder regeneration had probably occurred. However, the possibility of distention of the trigone to form the new cavity could not be ruled out. Therefore, six additional dogs were subjected to subtotal cystectomy, ileal loop, and temporary artificial bladder implantation. The edges of the bladder resection were marked with nonabsorbable sutures. In three fully evaluable dogs a urinary cavity was identified. This was mainly formed by trigonal distention. While the epithelium had regrown over a small area of fibrous tissue found at the dome of the reservoir, no smooth muscle regeneration was found. It is concluded that the new reservoir was formed by trigonal dilatation rather than by regeneration.     

Neovesical-urethral anastomotic stricture after orthotopic urinary diversion: presentation and management

OBJECTIVE

To assess the frequency, presentation, treatment, and outcomes of bladder neck contractures (BNCs) among patients who had an orthotopic urinary diversion after radical cystectomy.

PATIENTS AND METHODS

We retrospectively examined our single‐institution database of 788 patients who had a radical cystectomy from 1 January 1996 to 4 January 2006 for BNC; variables evaluated included presentation, degree of stricture/contracture, clinical management, and outcomes after management.

RESULTS

Of the 374 patients who had an orthotopic urinary diversion, 11 (2.9%) men developed BNC; four BNCs were between 17 F and 22 F, six were <17 F, and one was pinhole‐sized. Nine of the 11 patients presented with voiding difficulties, one in complete retention after complicated urinary tract infection, and one with new‐onset nocturnal urinary incontinence. The treatment of BNC included cystoscopic dilatation in the clinic in six and under anaesthesia in three, and transurethral incision with a Collins knife or holmium laser in seven. After treatment, all patients were instructed to use continuous intermittent catheterization (CIC). Ten patients had follow‐up data available after the intervention, with a mean (range) follow‐up of 40.6 (10.6–98.0) months. Six patients were stricture‐ free for a mean period of 35.4 (10.6–98.0) months, while four patients had a recurrence within a mean of 7.4 (1.3–17.1) months. At the last follow‐up, nine of the 10 patients were using CIC. No patient had significant daytime or night‐time incontinence after treatment.

CONCLUSION

BNC develops in a small proportion of patients undergoing orthotopic urinary diversion, with most patients presenting with voiding difficulty. Most will require transurethral incision rather than an office‐based dilatation. After endoscopic incision to correct BNC, we recommend CIC to ensure complete emptying and to maintain the patency of the anastomotic stricture.