When counseling patients about the complications of radical prostatectomy, most urologists spend a great deal of time discussing impotence and incontinence. Few urologists, in contrast, discuss another very common but not well known postoperative problem: shortening of the penis. While not noticed by some men, shortening of the penis can lead to significant problems with self esteem, sexual satisfaction, and quality of life after radical prostatectomy for prostate cancer. Despite these significant consequences, many urologists disregard it while others are simply not familiar with it. As a result, many patients agree to and proceed with a radical prostatectomy without being aware of this postoperative issue and do not take any steps to minimize it. In this post, I will discuss shortening of the penis, how often it occurs and what, if anything, can be done to prevent or limit its occurrence.
It Happens More Often Than You Think
Despite its obscurity, shortening of the penis is actually a common complaint of men undergoing radical prostatectomy. Studies have shown that nearly half of men undergoing prostatectomy demonstrate some decrease in penis size postoperatively. The average decrease in flaccid penis length at 1 year after surgery has been reported to be about 1.3cm. A larger decrease of 2.3cm (nearly an inch) has also been reported in the length of the erect penis after the same period of time. One study reported that, after prostatectomy, almost 20% of men lose 15% of the length of their penises when measured in the erect state. You can imagine that such a decrease is noticeable and disheartening for a large number of men.
What Causes Shortening of the Penis ?
Many theories have been advanced, speculating about the root cause of shortening of the penis. One such theory that has been debunked (for the most part) is that of tension from the urethra. It was thought that because the prostate is removed, tension is created in bringing together the bladder and urethra. As a result, the urethra is pulled up towards the bladder, simultaneously pulling the penis into the body and shortening it. This theory does not make much anatomic sense as the urethra is tethered to the part of the pelvic muscles called the urogenital diaphragm. As a result, the urethra cannot really get pulled much in either direction, limiting its ability to shorten the penis.
Recently, a more comprehensive theory has emerged which divides the causes for shortening of the penis into short and long term. Shortening of the penis can first be noticed from the time of catheter removal through the first month or so after surgery. This initial shortening is thought to occur directly as a result of damage to the nerves traveling around the prostate that are responsible for erections. Damage to these nerves at the time of surgery leads to stimulation and hyperfunctioning of nerves that are part of the sympathetic nervous system. These nerves, responsible for the “fight or flight” response, release adrenaline which leads to contraction of smooth muscle in the body. These sympathetic nerves send impulses to the penis where the smooth muscle of the erectile bodies contract. This contraction of the penis pulls it into the body and makes it appear shorter. Fortunately, this is a short term response which is reversible.
Long term shortening, in contrast, is caused by progressive, irreversible changes to the structure of the penis. These changes are brought about through two mechanisms:
1) Permanent nerve damage experienced during surgery: When nerve damage occurs anywhere in the body, the tissues to which the damaged nerves supply impulses usually experience atrophy or breakdown. This can often be seen in paraplegic, wheelchair bound people in whom the loss of nerve signal causes a significant decrease in the size and muscle mass of the legs. The same can be said of the penis after nerve damage during prostatectomy. If permanent nerve damage occurs, the lack of impulses to smooth muscle of the penis leads to an atrophy or breakdown of the tissues responsible for erections and causes the penis to shrink both in length and girth.
2) Decreased transport of blood and oxygen through the erectile tissue of the penis: As is widely known, loss of erections is a common side effect of prostatectomy, particularly in the first few months after surgery. Erections lead to the circulation of oxygen-rich blood through the penis which nurtures it and keeps it healthy. If no erections occur for extended periods of time, the lack of circulation of this oxygen-rich blood leads to fibrosis or scarring of the erectile tissue of the penis, also leading it to shrink in terms of length and girth. This phenomenon has been demonstrated both through experimental animal studies and human studies.
Preventing Shortening of the Penis
While causing problems like shortening of the penis, radical prostatectomy still remains a vital tool in the fight against prostate cancer. Most men will proceed with surgery to cure their prostate cancer even with the knowledge that a prostatectomy may significantly decrease the length of the penis. But what if we could prevent or, at least, limit shortening of the penis after prostatectomy? Studies have demonstrated that this, indeed, is possible. While short term, reversible, shortening of the penis cannot truly be avoided, long term, permanent, shortening can be prevented or limited.
The most effective method of minimizing the chance of shortening the penis depends on avoiding the permanent damage to the penis that I described above. This requires some work by both surgeon and patient. First, damage to the nerves around the prostate needs to be avoided by the surgeon. The way to accomplish this task is to perform a meticulous nerve sparing prostatectomy. Of course, every prostatectomy is always a fine balance between cancer control and nerve sparing. That is why a skilled, experienced surgeon is vital to performing a prostatectomy that cures cancer with a minimal sacrifice of the nerves. Studies have demonstrated that the most important, independent, predictor of shortening of the penis is nerve sparing during surgery. In fact, one study demonstrated that successful nerve sparing prostatectomies performed on potent men who maintained good erections after surgery led to no change in the length of the penis whatsoever.
Once the surgery is performed, the rest of the responsibility to prevent long term shortening of the penis falls on the patient. Studies have shown that various “rehabilitation” strategies can ensure the continued circulation of oxygen-rich blood through the penis and prevent the scarring of the penis that I mentioned above. As a result, men who undergo such “penile rehabilitation” after surgery have demonstrated less extensive shortening of the penis. One study, for example, evaluated the benefit of using a vacuum erection device daily from the time the catheter is removed after nerve sparing radical prostatectomy. Measurements of penis length prior to and 3 months after surgery demonstrated a decrease in the length of the penis by more than 1 cm in only 3% of men who used the vacuum erection device regularly as opposed to 67% of men who were not compliant with the protocol. Another study of men undergoing nerve sparing robotic prostatectomy evaluated a rehabilitation regimen of daily Viagra for 9 months after surgery. The study found that at 1 month after surgery, men suffered from a decrease in penis length of about 0.6cm. This decrease in length was thought to be due to the short term, reversible process described above. By 9 months after surgery, however, this decrease in the length of the penis was no longer present as the measured penis length appeared to be equivalent to that noted preoperatively. Hence the short term process was reversed and the long term, irreversible process of shortening was prevented through the regimen of rehabilitation.
Take Home Message
Shortening of the penis is a very real complication of radical prostatectomy. Although not often talked about, this phenomenon can lead to significant impairment of self esteem and a decrease in the quality of life for men undergoing surgery for prostate cancer. The occurrence of shortening of the penis is lamentable in that, for the most part, it is preventable. With meticulous nerve sparing, permanent nerve damage and subsequent damage to the penis can be limited. Similarly, through a regimen of penile rehabilitation (via pills, injections, or pumps), many men can prevent or decrease permanent scarring of the penis and the inevitable, irreversible shortening it causes.
