RECONSTRUCTIVE UROLOGY

Critical evaluation of the problem of chronic urinary retention after orthotopic bladder substitution in women
Ali-El-Dein B, Gomha M, Ghoneim MA
From the Urology and Nephrology Center, Faculty of Medicine, Mansoura University, Mansoura, Egypt
J Urol. 2002; 168:587-92

• Purpose: We studied the possible causes of chronic retention after radical cystectomy and orthotopic bladder substitution in women.
• Materials and Methods: Between January 1995 and January 2001, 136 women with a mean age plus or minus standard deviation of 52 ± 8 years underwent standard radical cystectomy and orthotopic substitution for organ confined bladder cancer. Videourodynamics, pelvic floor electromyography, pelvic floor magnetic resonance imaging and pan-endoscopy were done. In the last 37 cases some technical modifications were adopted to circumvent the development of chronic urinary retention.
• Results: One woman died postoperatively of massive pulmonary embolism. Of the 100 patients evaluable at a mean followup of 36 months 95 were continent in the daytime, 86 were continent at night, 2 were completely incontinent and 16 were in chronic retention. Videourodynamics showed that retention was mechanical in nature due to the pouch falling back in the wide pelvic cavity, resulting in acute angulation of the posterior pouch-urethral junction. In addition, herniation of the pouch wall through the prolapsed vaginal stump was observed in most cases. Pelvic floor electromyography demonstrated complete pelvic floor silence during voiding. No abnormality of the pelvic floor or rhabdosphincter was noted on magnetic resonance imaging. Pan-endoscopy showed a normal urethra with no urethroileal stricture. A 4 mg. dose of the [alpha]1-adrenergic blocker doxazosin daily was ineffective, excluding the possibility that sprouting from adjacent adrenergic neurons into the denervated proximal urethral muscles may have been the cause of this problem. After omental packing behind the pouch, suturing of the peritoneum on the rectal wall to the vaginal stump, suspension of the latter by the preserved round ligaments and suspension of the pouch near its dome to the back of the rectus muscle at cystectomy the incidence of chronic retention decreased from 18.7% (14 of 75 cases) before to 8% (2 of 25) after modifications. Furthermore, after vaginal wall descent was mechanically corrected by a pressary there was significant improvement in evacuation.
• Conclusions: Strong evidence was provided that chronic urinary retention after orthotopic substitution is due to anatomical rather than to functional or neurogenic reasons. Modifications to increase back support of the pouch with ventral suspension near its dome and support the vaginal stump are recommended to avoid this complication.
  
  
• Editorial Comment
  Orthotopic bladder substitution in women is now an accepted form of urinary diversion in many centers worldwide. Favorable results in several hundred women published in the recent literature give evidence not only of the feasibility but also of oncological safety and good functional outcome of urethra-sparing cystectomy with subsequent anastomosis of a low pressure intestinal reservoir.
  One of the few drawbacks of orthotopic neobladders in women -contrary to initial speculations -is not an increased rate of urinary incontinence but urinary retention. The authors which have a large experience with this type of surgery tried to find an answer to this problem by altering their surgical technique over the years. They evaluated one hundred patients with a mean follow up of 36 months. 95% were continent in the daytime, 86% were continent at night and 16% had chronic retention. They changed their technique by trying to improve positioning and suspension of the neobladder. This was achieved by anchoring the vaginal stump with the help of the preserved round ligaments, cushioning of the neobladder floor with a pedicled flap, bringing down the remnant peritoneum over the anterior rectal wall to the vaginal stump, and suspending the pouch near its dome to the back of the rectus muscle. Thus the incidence of chronic retention decreased from 18.7% to 8% in their last 25 cases.
  This is truly an improvement and the modifications specified in the paper should be taken up by all surgeons. However, an 8% retention rate is still higher than in most series for male patients therefore it does not exclude functional and neurological reasons. It is difficult to believe that the angulation between the remnant urethra and the intestinal pouch should be the only reason. As outlined in the previous literature (which is well quoted in this paper) 3 major factors may be responsible for the higher incidence of urinary tension in females: 1)- an undefined level of urethral dissection in females (due to the absence of the prostate), 2)- partial autonomic denervation of the urethral smooth musculature, which plays a larger role in women due to its presence almost in the entire length of the urethra, and 3)- mechanical obstruction of the neobladder outlet which includes mucosal intestinal folds, an acute urethro-intestinal angle and hypermobility of the urethra.
  This paper shows valuable modifications in the technique of orthotopic bladder substitution in women, but it does not completely solve the problem by just trying to see only mechanical reasons for it.

Dr. Arnulf Stenzl
Chairman of Urology
Eberhard-Karls-University Tuebingen
Tuebingen, Germany