ERECTILE DYSFUNCTION

New Treatments Offer Hope for Impotence
An estimated thirty million American men suffer from erectile dysfunction or impotence and only a small percentage ever seek medical help. Today's studies indicate that physical disease factors are responsible for eighty to ninety percent of all impotence cases. Nearly all causes of impotence are treatable. Mention is given to the American Urologic Association, The Treatment of Organic Erectile Dysfunction, A Patient's Guide, which was used in preparing this discussion.

Physiology of Erections
An erection occurs as a result of complex interaction between the brain and nerves and blood vessels of the penis. The brain processes certain sensations which cause sexual arousal. These sensations may be psychological, such as erotic thoughts, or involve any of the five senses. The brain then sends nerve impulses directly to the penis via the penile nerves. The nerves may also be directly stimulated by manual stroking of the penis and by sexual intercourse. These nerves travel to twin erectile chambers, one on either side of the penis. These are called corporeal cavernosal bodies. When the nerves are stimulated, the blood vessels and penile tissue in the cavernosal bodies open up allowing an increase in blood flow into these chambers. Covering these chambers is a tissue called the tunica albuginea. Although this tunica is quite elastic in a relaxed state, as blood fills up the cavernosal bodies, the tunica becomes very hard. In addition, as the penis fills with blood, the veins draining the penis are compressed against this tunica. Thus, the blood is trapped in the penis. The erection is maintained as long as adequate stimulation is continued from either the brain or external manipulation.

Causes of Erectile Dysfunction
The causes of erectile dysfunction are divided into two main categories: psychological and physical. The psychological include stress and anxiety. This can also lead to "performance anxiety" for a man because of his anxiety to get an erection and finds he cannot perform which then causes more anxiety and a vicious cycle ensues. Depression and other psychiatric disorders may also cause impotence.

Many physical diseases can cause erectile dysfunction. By decreasing blood flow to the penis, atherosclerosis and other diseases that effect the body's vascular system are major risk factors for erectile dysfunction. Other diseases include diabetes, high blood pressure, multiple sclerosis and alcoholism.

Cigarette smoking, by way of its effect on the vascular system, may also cause impotence. Impotence may also result from traumatic injury to the pelvis which can then injure either the nerves or blood vessels which go to the penis. In much the same way, colon, bladder or prostate surgery can result in similar injuries which can lead to erectile dysfunction. A very important and often overlooked cause of impotence is medication. Many common prescription medications can cause erectile dysfunction.

Certain hormone levels, if outside the normal range, can also cause erectile dysfunction. These include testosterone, prolactin and thyroid hormones.

Diagnosis
The five components of the diagnostic evaluation are medical history, sexual history, physical exam, laboratory evaluation and special diagnostic tests.

Medical History
Consists of questions covering the patient's general health, potential systemic diseases, current medications and social history (including alcohol and tobacco use).

Sexual History
Focused questions regarding the frequency of intercourse, the duration and quality of erections, the libido and early morning erections. Additional questions may help to rule out the possibility of psychological factors.

Physical Examination
Attention is given to the male genitalia including the penis, testicles and prostate. A screening for adequate sensation and vascular function is also performed.

Laboratory Evaluation
Blood and urine samples will be obtained.

Special Diagnostic Testing
This may include injection of medication into the penis to assess its vascular functioning. An ultrasound may be performed at the same time to give a more precise measurement of the blood flow into the penis. Another type of test, nocturnal penile tumescence monitoring (Rigi-scan) involves measuring the erections that occur normally during rapid eye movement sleep.

Treatment
Vacuum Erection Device (VED) - A vacuum erection device is used to pull blood into the penis. A constricting band is then placed on the base of the penis to allow the erection to be maintained for twenty to twenty-five minutes. These devices are safe, inexpensive and can be used as often as desired. They have virtually no side effects.

Penile Implants - Semi-Rigid - The penis is maintained in a constant semi-rigid state. The penis is positioned downward when intercourse is not desired and upward when it is desired.

Inflatable penile prosthesis - A reservoir and pump are attached to the implant which is surgically placed into the penis. When the pump (in the scrotum) is compressed fluid from the reservoir fills the implant causing the penis to become erect. When the penis is bent or a release button is pushed, the penis becomes flaccid as the fluid leaves the penile cylinders and goes back into the reservoir.

Once a penile implant is inserted, it is usually not possible to change to other treatment options. In addition, the device may become infected or have mechanical failure which would require another operation to remove the implant ( 5 - 10 % risk). Despite these potential problems, patients who ultimately choose this option have the highest satisfaction rate of any patient group treated for impotence.

Penile injections - Using a small needle a drug is injected directly into the penis prior to intercourse either prostaglandin E-1 (Caverject) or a combination of vasoactive compounds (papaverine, phentolamine and prostaglandin) are used. The quality of erections are usually excellent. The main risk of this treatment is actually having an erection that lasts too long which can injure the penis. An erection lasting for more than three to four hours requires immediate attention by the urologist to remedy the problem. This complication occurs infrequently. Most erections last thirty to sixty minutes. Long term use may lead to scar tissue formation at the site of injection.

Urethral suppository - MUSE is a non-injectable form of alprostadil consisting of a plastic applicator that contains a very small urethral suppository. In clinical studies sixty-five percent of men were able to achieve successful intercourse with MUSE compared to only nineteen percent of men who were given a placebo suppository. Side effects are minimal.

Yohimbine - This is long considered an aphrodisiac, Yohimbine has been prescribed for many years in the treatment of impotence. It acts by indirectly increasing blood flow to the penis.

Two new oral medications not yet available in this country are quite promising.

Apomorphine SL is a medication which is placed under the tongue and is directly absorbed into the bloodstream. In one clinical study seventy percent of patients reported excellent erections.

Silbenafil is a medication which improves blood flow to the penis by inhibiting an enzyme called phosphodiesterase.