Artificial urinary sphincter placement in the irradiated post-radical prostatectomy patient

March 1, 2010

Although mesh slings have become increasingly commonplace for the treatment of mild male stress urinary incontinence, the artificial urinary sphincter remains the gold standard of treatment for managing severe post-prostatectomy incontinence.

Pre-op evaluation

We believe that a single office evaluation is ample to determine the appropriate treatment plan for the vast majority of patients. Pad weights and formal urodynamic assessments may occasionally be informative, but we have not found it necessary to employ these tests routinely. Although irradiated patients evaluated by preoperative urodynamics tend to demonstrate an earlier first sensation, smaller cystometric capacity, and more detrusor instability versus non-radiated patients, no differences have been found in postoperative outcome based on urodynamic findings (Neurourol Urodyn 1998; 17:493-8; J Urol 2007; 177:1021-5).

Standing cough test. We have found the "standing cough test" to be a simple and reliable maneuver for evaluating all potential AUS patients to confirm the degree and the stress-related nature of the leakage. The implanting surgeon should use this opportunity to assess the undergarments to document pad type, the degree to which the pad is soaked, and to assess for other pathology such as inguinal hernias or fungal rashes, which may require attention prior to AUS insertion. Most AUS candidates have marked sphincteric compromise and thus leak copiously, often with a steady urinary stream during a simple cough in the standing position, regardless of how full the bladder is.

Once gross stress urinary incontinence is visually confirmed in this manner, we are comfortable scheduling AUS implantation without pursuing further diagnostic testing. Those having minimal leakage during the standing cough test and a history of mild incontinence (fewer than three pads per day) are better suited for sling procedures. Because sling procedures are simpler and safer than the AUS, they are preferred whenever appropriate. We have attained social continence (0-1 pads per day) in roughly 80% of men with mild incontinence who are implanted with the AdVance sling (American Medical Systems), but we have been disappointed with outcomes of sling procedures in men who have more than the three-pad-per-day threshold, and recent experience has indicated a reduced success rate of roughly 59% in irradiated patients (Eur Urol, Sept. 8, 2009).

Bladder neck contracture. As with all post-prostatectomy patients, the next important aspect of the preoperative evaluation is to consider the possibility of a concomitant bladder neck contracture (BNC).

History of prior bladder neck dilations or incisions should alert the implanting surgeon to the possibility of a concomitant BNC, which we prefer to stabilize initially via transurethral incision prior to AUS implantation in a staged manner. In questionable cases, office cystoscopy should be performed to confirm bladder neck patency and assess the quality of the tissues and degree of sphincteric coaptation; however, if low suspicion exists for BNC, placement of a 14F urethral catheter (not 16F) at the time of surgery has proven to be a practical and simple way of avoiding unnecessary bladder neck instrumentation.

If transurethral bladder neck incision is performed, office cystoscopy should be performed 2 months later to confirm patency prior to AUS surgery. We feel it is important to stage the bladder neck incision well in advance of the AUS procedure in order to limit subsequent transurethral instrumentation, which may damage the delicate urethra under the sphincter cuff.