In my last post, I stressed the point that most men will regain continence within 12-18 months after prostatectomy. I emphasized that although men undergoing prostatectomy should be proactive about pelvic floor muscle exercises to regain their continence more quickly, they should also remain patient because the vast majority of men do reach almost complete if not total dryness after prostatectomy. For some men, however, this relief from urinary incontinence never comes. Ten to fifteen percent of men remain significantly wet even years after surgery. For some of these men, this incontinence requires changing diapers several times per day which ruins their quality of life, destroys their self esteem, and limits their ability to take part in beloved pastimes and activities. For these men, more aggressive options are available to limit the leakage of urine. In this post I review the invasive, surgical treatments of urinary incontinence. I, again, stress that these options should be reserved for intractable incontinence that persists 12-18 months post prostatectomy and beyond.
Urethral Bulking Agents
The least invasive surgical option for refractory incontinence after prostatectomy is the injection of urethral bulking agents. Such a procedure is performed using a camera to visualize the inside of the urethra and, specifically, the area of the urinary sphincter. Once this muscle is visualized, a bulking agent (gluteraldehyde crosslinked collagen) is injected endoscopically (through the camera) into the lining of the sphincter. The idea behind this treatment is to “bulk up” the sphincter, increasing the resistance to urine travelling from the bladder. Early studies on the use of urethral bulking agents after prostatectomy were encouraging. One study reported that 58% of men with incontinence who underwent the procedure had either good or at least improved results at a follow up of 10.3 months. More recent studies were not so positive, however, with reports of complete dryness of 8-17% and social dryness (no more than 1 pad per day) of 38% after multiple injections. A recent study of over 300 men treated with injectable bulking agents reported that men undergoing the procedure still required an average of up to 3 pads per day. The same study reported that the therapy was only effective for an average of 6 months, after which another injection was required. Due to these suboptimal results, bulking agents are generally NOT recommended for men with incontinence after prostatectomy.
Male Slings
A more invasive surgical option for men with incontinence after prostatectomy is the male sling. While numerous types of slings are commercially available, they all share a common mechanism of action: compression of the urethra. As with the bulking agents, the idea is to compress the urethra so as to increase the resistance to urine leaking from the bladder. Unlike the direct injection of agents into the sphincter, however, slings are secured underneath the urethra. Created as an artificial polyester mesh, the sling is like a hammock which sits under the urethra to serve as a backstop and provide gentle pressure to restrict urinary leakage.
Various versions of male slings date back to the late 1990s. The first male slings were fashioned after slings used for female incontinence during the same time period. The hammock portion of the sling was connected to sutures (strings) that were pulled out above the muscles of the anterior wall of the abdomen (the muscles referred to as a “six pack” in those of us who work out). The sutures would then be tied above these muscles(but below the skin) to secure the sling in place. The whole procedure could be carried out through a small incision underneath the scrotum and another, even smaller, incision just over the bladder. A study evaluating men undergoing this early version of male slings reported complete dryness in 56% and satisfaction in 90% of men undergoing the procedure.
This early version of the male sling was refined in 2001 with the development of the bone-anchored sling. This new variant avoided passing sutures through the abdomen (and the associated risk of damaging the bladder and intestines) in order to secure the sling. Instead, this new sling was secured in place under the urethra via sutures that were actually anchored into the pelvic bones adjacent to the urethra. Success rates reported with the bone anchored sling have been variable, ranging from 37-87%, depending on the definition of complete continence.
Diagram of a Bone Anchored Sling
More recently, yet another version of the male sling has been developed. This version is called the Transobturator (or AdVance) Sling. The sling, also placed under the urethra for compression, is secured by passing it through a canal within the pelvic bones. As such, the synthetic material is passed through an incision underneath the scrotum and out of another incision in the inner thigh (just underneath the groin crease). The sling is then cut at the skin surface of the incision in the thigh so it is not visible after surgery. The results of this technique mirror those of the bone anchored sling. The transobturator sling and bone anchored sling
are currently the two most commonly used slings for incontinence after prostatectomy.
Diagram of a Transobturator Sling
Like any other surgery, implantation of the male sling can result in complications. Urinary retention can sometimes be experienced (3%) if the sling is made to tight, requiring a subsequent surgery to loosen or remove it. Because the sling is a foreign object within the body it can become infected (6%) or can actually erode into the urethra (2%). Either of these complications requires a repeat operation with complete removal of the sling.
Artificial Urinary Sphincter
Although more invasive then urethral bulking agents or male slings, the artificial
urinary sphincter (AUS) remains the gold standard for men with persistent incontinence after prostatectomy. The AUS is composed of three interconnected parts. The main part of the device is comprised of an inflatable cuff which is wrapped around the urethra (in the same location as where the male sling is usually placed). The cuff is connected to a reservoir (containing fluid) that is implanted in the abdomen and a pump that is implanted in the scrotum. At baseline, the cuff encircling the urethra is inflated with fluid. As such, the cuff compresses the urethra, preventing leakage of urine from the bladder. However, when the patient pushes on the pump within the scrotum (which can be manipulated through the skin), fluid from the cuff is transferred to the reservoir. When all of the fluid is transferred from the cuff to the reservoir, the cuff is deflated and no longer compresses the urethra. This allows urine to flow from the bladder and out of the penis. The fluid in the reservoir drains back into the cuff after a fixed period of time, inflating it and allowing it to compress the urethra again. The whole process is carried out via hydraulics.
Diagram of Artificial Urinary Sphincter
The advantage of the AUS is that it replicates normal continence. Men with the AUS remain dry until they want to void at which time they activate the device, allowing the urine to drain for a set period of time. Success rates with the AUS have been notable. Initial studies reported complete dryness ranging from 79-100% with one study finding a decrease in pad usage from 2.7 to 1 per day. More recent studies have demonstrated social continence (up to 1 pad per day) of 58-88%. There are some drawbacks, however. First, any man that wants an AUS needs some level of manual dexterity that will allow him to operate the pump in the scrotum. In addition, as with all machines, the device can and does break down (6% rate over 5 years), requiring the parts to be removed or replaced through further surgery. Other complications associated with an AUS include infection (5.5%) and erosion into the urethra (6%). As with the male sling, either of these two complications requires removal of the device. Another potential complication is recurrent incontinence. This complication usually occurs due to urethral atrophy, which prevents the cuff from successfully compressing the urethra. In this situation, a repeat procedure is performed in which a second (tandem) cuff is added to provide additional compression of the urethra.
Take Home Message
While most men will eventually regain continence after prostatectomy, some will continue to have moderate to severe, debilitating leakage. Fortunately, men with this complication still have hope in the form of surgical techniques. While minimally invasive and creating the least risk, urethral bulking agents are not very effective and generally not recommended for the treatment of incontinence after prostatectomy. Male slings, although somewhat more invasive have been demonstrated to have significant efficacy and are being used more and more commonly for mild to moderate incontinence. The gold standard, however, remains the artificial urinary sphincter. Although not a panacea and definitely plagued by its own risks and complications, the AUS has provided reliable dryness for men with moderate to severe incontinence after prostatectomy. Regardless of the technique chosen, the decision to proceed with surgical management should be considered carefully after thoroughly weighing the risks and benefits with a qualified urologist. This decision should not even be considered until at least a year after surgery.
