Restoring sexual function after prostate surgery

by Karen Schroeder, MS, RD

Impotence. It is, perhaps, one of the most disturbing words a man can hear. And for men battling prostate cancer, it is a very real possibility. However, a new surgical procedure may prevent impotence that often occurs after surgery to remove the prostate gland.

Surgical removal of the prostate gland, called a radical prostatectomy, is often done when cancer is contained within the prostate gland (T1 or T2 cancers). This surgery can be very effective at curing prostate cancer. However, it also carries a high risk of causing long-term erectile dysfunction, or impotence. This risk is especially high when one or both of the cavernous nerves are cut.

The cavernous nerves are two tiny nerves situated alongside the prostate gland that carry signals to the penis to fill with blood and become erect. In some cases, the surgeon is able to leave these nerves intact, and possibly preserve erectile function. But for technical reasons, a portion of one or both may need to be removed. Some men—about 1/3 of those with just one nerve left intact—are able to have an erection; this depends on factors such as age and sexual function before surgery. When both nerves are severed, impotence is virtually certain.

Not all cases of impotence after prostatectomy result from trauma to the cavernous nerves. However, since this is a relatively common cause, doctors theorized that patching up these nerves could restore erectile function in many patients.

In 1997, Peter Scardino, MD, a urologist, and Rahul Nath, MD, a plastic surgeon, performed the first nerve grafting during a radical prostatectomy. They removed a tiny portion (a graft) of the sural nerve, which is located in the ankle, and used it to reconnect the severed cavernous nerve.

The grafted nerves do not function as well as the original intact nerves, but can restore erectile function to about one-third of men who have had both cavernous nerves cut and grafted during surgery. Another one-third of men receiving two grafts are able to achieve an erection with the help of the drug Viagra. Among men who have one intact nerve and one grafted, about 70% regain sexual functioning.

The portion of nerve removed from the ankle is only about 5 millimeters long. The main risk involved is a rare and treatable one—the formation of a painful growth at the end of the sural nerve where it has been cut.

Erectile ability is not restored immediately after the grafting procedure. During the first six months, there is typically no function, but erections gradually return in time. It can take up to two years to know for certain if the grafting will work. Typically, younger patients are more likely to regain sexual function.

The cavernous nerves are only about 3-4 millimeters in diameter. Therefore, grafting must be done during the prostatectomy, when the nerves are first cut; otherwise, the cut nerves would be virtually impossible for a surgeon to find and repair. Each graft takes about 30 minutes.

Grafting is still considered experimental, but since 1997 it has been done more than 300 times in six countries worldwide. In the U.S., grafting is done at the following health centers:

• Columbia University
• Cornell University
• University of Washington
• University of Michigan

Grafting is not appropriate for all men with prostate cancer. But this does not mean that impotence is inevitable. Other options to help restore erectile function include:

Penile implant

A device surgically placed in the penis to help a man achieve erection. There are three main types: rods, simple inflatable devices, and complex inflatable devices.

Prostaglandin E1

A substance naturally produced in the body that can produce erections. As a medication, it can be injected with minimal pain into the base of the penis 5 to 10 minutes before intercourse, or introduced into the urethra as a suppository. The dosage can be increased to prolong erection. Side effects include pain, dizziness, and prolonged erection.

Vacuum devices

These are mechanical pumps that are placed around the entire penis before intercourse to produce an erection. The mechanics of these devices may not allow for ejaculation.

Sildenafil citrate (Viagra)

A drug used to treat male impotence. Viagra will not work if both nerves have been damaged or removed. The most common side effects of Viagra are headache, flushing (skin becomes red and feels warm), indigestion, light sensitivity, and other visual problems. People who take nitrate medications to manage angina and other heart problems should never use Viagra. These medications can interact to cause very low blood pressure, a complication that can be fatal.