What is a Bladder Neck Contracture?
The prostate is usually located between the bladder and the urethra. I often describe the relationship to patients in the following manner: the bladder is like an upside down fishbowl which is connected to a donut (the prostate) which is subsequently connected to a straw (the urethra). Urine leaving the bladder goes through the donut hole of the prostate and out the urethra. During a prostatectomy, the prostate is removed, requiring this plumbing to be rerouted. In order to do this, the “neck” of the bladder, which was previously attached to the prostate, is sewn directly to the urethra tube. In 2-20% of cases, that connection gets scarred down to form a bladder neck contracture. The extent of this contracture can be variable, ranging from a mild narrowing to a complete obliteration of the connection. Either way, a bladder neck contraction can create significant difficulty with the passage of urine from the bladder to the urethra.
What Causes a Bladder Neck Contracture?
While the true causes of bladder neck contractures have not been definitively elucidated, numerous theories have been presented. The two most popular explanations include:
1) Gaps in anastomosis: When the anastomosis (the surgically created connection between the bladder neck and urethra) is made during a prostatectomy, several problems can occur. First, the sutures placed in the bladder or urethra can tear. Also, bleeding from the surgery can create a large clot called a hematoma which can insinuate itself between the stiches and stretch the anastomosis. Either of these situations will create gaps in the anastomosis between the bladder neck and urethra. The human body has a natural tendency to fill gaps with fibrotic tissues or scar. As a result, gaps in the anastomosis allow scar tissue to form which, in turn, creates a bladder neck contracture.
2) Poor blood supply: Many urologists have postulated that bladder neck contractures occur due to decreased blood supply to the anastomosis. Generally, when a tube or connection in the body does not get an adequate supply of oxygen-rich blood, it gets obliterated by scar tissue. This situation, the theory proposes, is exactly what creates a bladder neck contracture. So what causes poor blood supply to the anastomosis? Several factors have been implicated. First, tying down the sutures connecting the bladder and urethra too tightly can strangulate the blood vessels to the area and decrease the flow of blood. Others have argued that prostatectomies performed without nerve sparing can also decrease blood supply to the area. Finally, some men are simply predisposed to problems with blood vessels. Men with diabetes, high cholesterol, and heart disease, for example, demonstrate poor blood flow to all parts of the body, including the anastomosis. Not surprisingly, older men (who are more prone to problems of blood flow) are more likely to experience bladder neck contractures than their younger peers.
What are the Signs of a Bladder Neck Contracture?
Men usually start to experience symptoms from a bladder neck contracture between 3-6 months after surgery. The initial symptom in most men is a subtle slowing of the urinary stream. This symptom is often ignored until it gets substantially more dramatic. Often times, men actually complain of urinary incontinence after a period of dryness following radical prostatectomy. This leakage is due to the overflow of urine from a bladder distended with urine that is barely able to escape into the urethra. Eventually, if left unattended, bladder neck contractures lead to complete urinary retention. Unable to urinate, men present to the emergency room where doctors and nurses are usually unable to negotiate a catheter into the bladder due to the narrowing from the contracture. At this point, an urologist needs to be called to provide treatment.
How Are Bladder Neck Contractures Treated?
Men complaining of symptoms suggestive of a bladder neck contracture first need to be evaluated with a cystoscopy. This procedure, done in the urologist’s office with local anesthesia, involves passing a flexible camera through the penis and towards the bladder. With this camera, an urologist can tell if there is any scar tissue creating a blockage at the anastomosis between the bladder and urethra. In addition, he can determine if there are any other problems in the bladder or urethra that could be mimicking these symptoms.
If a bladder neck contracture is confirmed during an office cystoscopy, a decision then needs to be made to determine how to proceed. One option is to perform a gentle dilation at that time under local anesthesia. A dilation is performed with the use of a variety of tubes of varying diameters. The urologist starts by passing the smallest tube through the contracture and into the bladder. He then stretches the contracture by passing larger and larger tubes through it until a catheter (like the one in place after prostatectomy) can be successfully placed in the bladder. This catheter usually stays in place for a few days and is then removed.
Although definitely tolerable, a dilation performed under local anesthesia can be uncomfortable. As a result, some men choose to have their bladder neck contractures treated in the operating room under more extensive anesthesia. In the operating room, more extensive procedures can be offered besides just dilation. For example, a larger camera can be advanced to the location of the contracture and a knife (within the camera) can be used to cut the contracture. This procedure also requires a catheter for a few days.
Regardless of which procedure is chosen, bladder neck contractures are successfully managed with a single treatment in 60-80% of cases. Some men, however, have very tough contractions that recur soon after treatment. For these men, more aggressive operative therapy is needed. One such therapy involves aggressively and deeply cutting the contracture with a hot knife, also through an endoscopic approach using the camera. If this does not work, some surgeons use a permanent, metallic stent (called Urolume) which can be deployed across the contracture. These aggressive treatments usually lead to significant incontinence. As a result, most men that are successfully treated with such aggressive options subsequently also need to undergo placement of an artificial urinary sphincter (AUS) to help them overcome the leakage of urine. I describe the AUS in detail in my previous post on surgical options for urinary incontinence after prostatectomy: http://myprostatedoc.blogspot.com/2011/06/managing-urinary-incontinence-after_26.html
Take Home Message
Bladder neck contractures develop in a small proportion of men undergoing radical prostatectomy for prostate cancer. Presenting 3-6 months after surgery, this scar tissue at the connection between the bladder and urethra often causes slow stream and occasionally retention of urine. In some men, it can also cause urinary incontinence. Men with these symptoms after prostatectomy should seek expedient evaluation and, if necessary, treatment for bladder neck contracture from their urologist. Such proactive management can save a great deal of potential stress and discomfort during a late night visit to the emergency room .
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This blog is not a medical practice and cannot provide specific medical advice. This information should never be used to replace or discount the medical advice you receive from your physician