Side Effects

Erectile Dysfunction

Erectile dysfunction is the inability to achieve or maintain an erection adequate for sexual intercourse. Erectile dysfunction refers to erection function only. Men with erectile dysfunction have normal sensation and sex drive and are able to achieve orgasm.

Erections and ejaculation

The penis is a complex structure of muscle, blood vessels and nerves. When a man become aroused, nerves send messages to relax the smooth muscle tissue in the penis, allowing the arteries to pump more blood into the chambers inside the muscle. As the penis lengthens, the veins stretch and shut themselves off, trapping blood inside the penis.

Sperm is produced in the testicles and transported through tubes to the prostate gland. Semen, the solution that carries sperm, is produced by both the prostate gland and the seminal vesicles, glands attached to the prostate. Prior to ejaculation, tubes from the testicles carry sperm to the prostate, where sperm mixes with semen. This fluid is then ejaculated during orgasm by a connection to the urethra called the ejaculatory ducts.

After ejaculation, the nerves stop sending messages, the smooth muscle contracts, blood flow to the penis is reduced, the veins loosen their hold so blood can leave the penis and the erection fades away.

How prostate cancer treatment affects erections

Some prostate cancer treatments may affect the nerves or arteries responsible for erections; others may affect libido, or sex drive.

Radical prostatectomy

The bundles of nerves sitting on either side of the prostate send messages to the penis to initiate erections. Even if the nerve bundles are not removed during radical prostatectomy, they may still sustain damage and are very slow to heal. However, even if the bundles are not injured during surgery, some men will be experience erectile dysfunction afterward; the reasons are unclear.

Another common reason for difficulty with erections is that the veins in the penis may have suffered trauma during surgery and are unable to keep blood trapped inside the penis.

Erection problems can also result from injury to the blood vessels in the penis, although this is extremely rare in radical prostatectomy.

Likelihood of erectile dysfunction following surgery

The effect of surgery on the ability to achieve an erection is related to a man's age and whether nerve-sparing surgery was performed.

The likelihood and duration of erectile dysfunction following radical prostatectomy depend on the following factors:

• The extent of the cancer. Men whose cancers are small and confined to the prostate have a greater potential of regaining erectile function than men with more extensive tumors.
  
  
• The quality of erections prior to surgery. Men with good erections are far more likely to recover potency after surgery or radiation therapy than those with erection difficulties prior to treatment.
  
  
• Age. Men in their 40s have the best potential of potency returning after nerve-sparing radical prostatectomy. Men in their 70s and older have significantly diminished potential to regain potency, even if they have nerve-sparing surgery.
  
  
• The skill of the surgeon. The American Cancer Society reports that after standard (not nerve-sparing) radical prostatectomy, between 65 percent and 90 percent of men will experience erectile dysfunction, depending on their age. A recent study reports that in the hands of a surgeons experienced in nerve-sparing radical prostatectomy, over 80 percent of men were potent (able to have unassisted intercourse with or without the use of Viagra) 18 months after surgery.¹ However, other studies report a much lower percentage of patients achieving potency following nerve-sparing surgery.

Radiation therapy

Unlike radical prostatectomy, radiation therapy may cause problems slowly and over time. The main cause of erectile dysfunction following radiation is damage to the blood vessels supplying the nerves responsible for erections. External beam radiation therapy appears to cause more problems with potency than brachytherapy.

Cryosurgery

When the prostate gland is frozen during cryosurgery, the nerve bundles controlling erections can often be permanently damaged.

Hormone therapy

The male sex hormone testosterone is responsible for sex drive, or libido, as well the ability to achieve an erection. When hormone therapy stops testosterone production, most men lose interest in sexual activity.

Treating erectile dysfunction

• Viagra
  Viagra is an oral prescription medication that has revolutionized the treatment of erectile dysfunction. It works by relaxing smooth muscles in the arteries of the penis, allowing more blood flow to produce an erection. Viagra does not improve sex drive; it only improves erections. It may cause mild side effects, including headaches, flushing and indigestion.
  

  Candidates for Viagra: Studies have shown that men with erectile dysfunction after prostatectomy respond well to Viagra if the nerve bundles on both sides of the prostate have been spared. However, Viagra is not effective when one or both nerve bundles have been damaged.

• Penile injections
  Medication that relaxes the smooth muscle of the penis and increases blood flow is injected with a tiny needle into the side of the penis. It usually takes about 5 minutes from time of injection for erection to occur; the erection lasts from 30 minutes to 2 hours. A doctor can generally teach a man or his partner to administer the injections in one or two office visits. Patients will have to return for follow-up visits, particularly at the beginning of treatment, to ensure they are receiving proper dosage of the medication.
  

  Advantages: The injections produce completely normal erections and are easy to prepare and administer. This treatment option does not involve surgery, is only minimally painful and can be used any time. Although self-injection therapy can cost up to $25 per injection, it is much less expensive than surgery.
  Disadvantages: Reports of satisfaction with this technique range between 50 percent and 70 percent. Some men report that the injections cause urethral pain and burning. Injections should be limited to once or twice a week to minimize risks of scars or penile damage. The most serious complication of penile injections is priapism, a painful condition where the erection persists and does not go away.

• Vacuum constriction or vacuum erection device
  A large plastic tube attached to a pump. Placed over a lubricated penis, the pump is activated, causing a vacuum in the tube. The vacuum allows blood to flow into the penis, producing an erection. A rubber ring is then placed around the base of the penis, trapping the blood and maintaining the erection. The ring must be removed after no more than 30 minutes to allow the blood in the penis to circulate and prevent penile swelling.Men who are able to achieve but not maintain erections may use the ring only.
  

  Advantages: The device works for almost everyone, regardless of nerve damage. It can be used as often as desired, as long as the ring is removed every 30 minutes.
  Disadvantages: The vacuum device costs hundreds of dollars and is available only by prescription. If the ring is too tight, it may cause pain or diminished sensation in the penis. The erection begins above the ring, so the base of the penis may swivel with erection. The device takes effort to use and the ring must be removed after no more than 30 minutes. It may be harmful to men who use blood thinners or have blood clotting problems.

• Penile implant
  A prosthetic device surgically implanted inside the penis.

  Advantages: High rates of satisfaction have been reported and implants can restore sexual function to normal levels.
  Disadvantages: Surgery carries the risk of complications including bleeding, scarring, or problems with anesthesia. Post-surgical pain is common. There is a small chance of infection that could require removal of the implant. Some men notice numbness at the head of the penis. The head of the penis remains soft during the erection, which may bother some men.

  
  1 Walsh PC, Marschke P, Ricker D, Burnett AL. Patient-reported urinary continence and sexual function after anatomic radical prostatectomy. Urology 2000;55(1):58-61.

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  The Prostate Cancer pages of this Web site are part of the Comprehensive Prostate Cancer Awareness Program (CPCAP), a major regional effort to reduce the rates of death and illness caused by prostate cancer in southwestern Pennsylvania. Funding for CPCAP is provided by a grant from the Commonwealth of Pennsylvania.

  
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