Urology Nurses Online: ARTICLES

Erectile dysfunction affects approximately 10 to 20 million men in the United States. During the last decade there has been a significant change in the management of patients with sexual dysfunction both because of our improved understanding of erectile physiology, and also because of the development of new and effective medical therapies.

For years, psychologic factors were implicated as the main cause of impotence (Masters & Johnson, 1970; Strauss, 1950; Wespes, Delcour, Struyven, & Schulman, 1986). However, during the last decade there has been a significant change in the management of patients with sexual dysfunction both because of our improved understanding of erectile physiology, and also because of the development of new and effective medical therapies. Erectile dysfunction affects approximately 10 to 20 million men in the United States (NIH Consensus Development Panel on Impotence, 1993). Losing erectile function is not an inevitable consequence of normal aging (Morley & Kaiser, 1993); however, it does become more frequent with age (Feldman, Goldstein, Hatzichristou, Krane, & McKinlay, 1994). Recent studies reveal that up to 70% of males 70 years old have some dysfunction and 50% have moderate or severe dysfunction (Padma-Nathan, 1996).

Most men with erectile dysfunction are thought to have organic impairment (Krane, Goldstein, & Saenz de Tejada, 1989), especially circulatory insufficiency. Erectile dysfunction is usually caused by an organic factor or disease, such as pelvic vascular disease, heart disease, hypertension and hypercholesteremia, diabetes mellitus, pelvic surgery and trauma, side effects of medications or neurodegenerative disorders, and the use of tobacco. Smoking doubles the probability of impotence with a given risk factor. Psychologic problems are also important contributing factors that can impair sexual performance, diminish self-esteem, and disrupting personal relationships (Feldman et al., 1994).

An erection is a hemodynamic balance between inflow and outflow of blood within the corpora (see Figure 1). The corpora cavernosa are the two bodies of erectile tissue running along the shaft of the penis. The dorsal and cavernosal arteries, which arise from the pudendal arteries, are the main determinants of arterial inflow. The erection is induced primarily by smooth muscle relaxation of the arterial vessels that deliver blood to the cavernosum, and of the cavernosal sinusoids where space is created so that the increased inflow of blood from the arteries has a place to collect. If adequate relaxation of the cavernosal muscle occurs, this causes an increase in the intracavernosal pressure, which then passively occludes the veins that exit the cavernosa through the tunica albuginea. The tunica is a thick, fibrous sheath that separately encapsulates each cavernosum. The occlusion of the veins by elevated intracavernosal pressure is the key step in retaining blood within the corpora, and this can only happen if adequate corporeal smooth muscle relaxation occurs. The relaxation of the muscles of the corpora and penile arterial vessels is mediated by nitric oxide, which is synthesized in the nerve terminals innervating these muscles. Any deviation from blood inflow or outflow can cause erectile dysfunction.

For a man to achieve an erection he must have normal neurologic innervation of an intact vascular tree and a normal libido. Therefore, when a man presents with the complaint of impotence, his problem can be traced to either a physiologic dysfunction based on a vascular and/or neurological etiology, a hormonal imbalance, and/or a psychologic etiology. Since about 90% of all patients with impotence have a physiologic problem, that is where most of the treatment options are focused.

DIAGNOSTIC INVESTIGATION

A thorough medical, social, and sexual history, paired with a physical examination, is absolutely necessary in helping to diagnose the underlying problem. An initial history is done to both identify reversible causes and to help differentiate psychogenic dysfunction from organic dysfunction. A complete history covers the patients age, his past medical history (including any injuries or surgeries), a complete listing of his medications, current or past use of tobacco, and alcohol intake history. The specifics of his erectile dysfunction must also be investigated. When did he first notice a problem, what was the problem, how did it progress, and how does he perceive the erections now? It is important to ask about nocturnal erectile function and how it differs from stimulated erections. How does he rate his morning erections, how does he rate his stimulated erections, how long do they last, and can he achieve penetration with these? Does he masturbate and are these erections any different? We use a 1 to 10 scale with 10 being the most rigid and usable erection.

Has he noticed a change or decrease in his ability to climax? If he answers "yes," is this because he has not tried to reach an orgasm because he hasn't had a full erection? Most men do not realize that they can still reach a climax without an erection.

You must also differentiate impotence from ejaculatory problems. Occasionally you will go through the entire history only to find out he has a problem with premature ejaculation, or anejaculation, which is not an erectile problem.

Another important area to cover is his libido. Is it poor, fair, or strong? And if it is poor, is it because of the frustration and fear of rejection he is feeling because he can't depend on a firm erection, or has he noticed an actual physical decrease in desire?

Exploring his relationship or relationships and lifestyle are the last pieces to the puzzle. Is he married, single, or having extramarital affairs? How long has he been in this/these relationships? Is he happy? Is he divorced or widowed, and if so, for how long? How has this affected his emotional well-being? Does he work? What are his hours, sleeping patterns, and stress levels? Does he associate any life stressors with a decrease in his erectile function?

Do not forget the partner of the man you are interviewing. Is she/he supportive of the patient? What is their desire level? Are they having problems with sexual dysfunction (for example, dryness, painful intercourse, or difficulty obtaining orgasm)? The more information you have, the easier it is to understand what treatment option might work for both partners.

Endocrine screening remains a necessary part of the evaluation for sexual dysfunction (Govier, McClure, & Kramer-Levien, 1996). A testosterone level should be drawn. A history of decreased libido and/or testicular atrophy on physical examination cannot predict hypogonadism; however, up to 15% of men with decreased libido and/or bilateral testicular atrophy can have low levels of testosterone (Govier et al., 1996). Prolactin levels are necessary in these patients as well as those with hypogonadism to rule out pituitary tumors. A Rigiscan, or a nocturnal penile tumescence test that measures nighttime erections, may be done for suspected psychologic impotence. It is important to note here that urologists and most urological nurses are not sex therapists. Patients or couples that require sexual counseling should be referred to a certified sexual therapist.

TREATMENTS: ORAL MEDICATIONS

Current treatments include oral medications, vacuum pumps, intracorporal injections, intraurethral applications, and penile prostheses. Each option should be discussed thoroughly with the patient before he decides to proceed with treatment. If possible, both the patient and his partner should be fully informed in an unbiased manner about recommended treatment options, relative benefits, and potential complications.

Yohimbine, an oral medication, supposed to increase blood flow, has limited efficacy. The American Urological Association in its clinical guidelines states that "...yohimbine does not indicate a significant role in treatment of organic erectile dysfunction÷reported benefits have been modest and there is a pronounced placebo effect" (Montague et al., 1996). We sometimes still use this drug at our clinic for men with a psychologic component to their erectile dysfunction, or for those who absolutely refuse any other type of therapy. Side effects for the drug include increased blood pressure, tachycardia, anxiety, and manic reactions. Most men receive prescriptions for this medication, but it is available over the counter at health food stores.

VACUUM DEVICES

Vacuum erection devices were initially designed many years ago, and since then a multitude of different models have been developed by numerous companies. The basic design is that of a cylinder that fits over the penis and rests snugly against the body. Air is pumped out of the cylinder either with a hand or battery-operated pump (see Figure 2). This creates a vacuum, thus drawing blood into the penis. When a firm erection is achieved, a rubber constriction band is applied at the base of the penis to maintain the erection. The cylinder is then removed. Unfortunately, the constriction band maintains blood in only the distal portion of the penis - from the body out - giving the erection a hinged effect at the body. However, it does provide the patient with a firm enough phallus for intercourse.

Advantages of vacuum devices include ease of use, noninvasive, and there is no limitation on frequency of use. Drawbacks can include the cumbersomeness of the device, lack of spontaneity, pain with the rings or pain from pumping too fast that causes the scrotal skin to become trapped in the cylinder, and appearance of the penis. The constriction rings act like a tourniquet and can make the penis appear blue to purple, slightly swollen, and be anywhere from cool to cold to the touch. Constriction can also diminish sensation to the head of the penis.

If a patient is considering a vacuum device, I tell them that if they do not have the type of relationship that allows them to laugh at themselves or with their partners during intimate moments, this will not work for them. I also instruct patients not to go home and use it right away. It is a device that they must practice with a couple of weeks before introducing it into sexual play. This practice time not only gets them comfortable with using the vacuum and the rings, but also helps to expand out the circulation system in the penis, allowing for better engorgement.

Complications with vacuum devices are minimal. Painful ejaculation has been reported because the constriction ring can increase intraurethral pressure during ejaculation. One system has been modified so that the ring will allow the ejaculate to pass through the urethra, alleviating this problem. The ring must be removed after 30 minutes or tissue damage may occur. This point must be strongly emphasized to all patients. Petechiae on the skin of the penis, scrotum, and glans can happen because of pumping the vacuum too rapidly. Vacuums are contraindicated for patients who are on anticoagulation therapy. Vacuum systems can range in price from $350 to $500 and most insurance companies will cover the cost of the device. Some companies have a 90-day return policy that allows the device to be returned with either a partial or full refund if the patient is not satisfied.

INTRACORPORAL DEVICES

Treatment of erectile dysfunction took a whole new turn in the early 1980s when it was discovered that injecting vasoactive drugs into the penis would produce a rigid erection (Virag, 1982).

Virag (1982) initially found that an injection of papaverine produced erections by causing arterial vasodilation and smooth muscle relaxation. Since that time, many substances have been identified. The most common agents used today include prostaglandin, papaverine, and phentolamine, either alone or in combinations with each other.

Prostaglandin is a naturally occurring agent that induces smooth muscle relaxation. In men, prostaglandin is released by the prostate during ejaculation. As an injectable agent, it has the advantage of being metabolized quickly within the penis, decreasing the incidence of prolonged erections (priapism) and intracorporal scarring. A disadvantage is the propensity to cause penile pain, which occurs in up to 30% of patients when used as a single agent (Schramek, Dorninger, Waldhauser, Konecny, & Porpaczy, 1990). This medication is used alone (PGE-1 or Caverject), or in combination with papaverine and phentolamine (tri-mix or 3-P).

Papaverine is a potent direct smooth muscle relaxant. When used alone it is inexpensive. However, there is a high incidence of priapism and intracorporal scarring, so its use as a singular agent has fallen out of favor. In addition, rare cases of reversible liver enzyme abnormalities have been reported (Lakin et al., 1990; Pagliarulo, Ludovico, Cirillo-Marucco, & Pagliarulo, 1996). Papaverine is commonly used in the tri-mix mixture and less commonly as bi-mix (a mixture of papaverine and phentolamine), usually for those patients who are sensitive to the PGE-1.

Phentolamine is an alpha-adrenergic antagonist that modulates the sympathetic nervous system. When it is used alone, it is very erratic, but in combination with the papaverine and PGE-1, it potentiates the desired effects of both drugs. Tri-mix also has a much lower incidence of pain than PGE-1 alone (Govier et al., 1993).

The most dangerous complication that can occur with injections is priapism. This is a full, firm erection that lasts more than 4 hours. It can become quite painful and if not detumesced can cause permanent tissue damage. The urology professional should be familiar with the methods used to reverse a priapism and should tell the patient how to contact the professional should a priapism occur. Other complications can include scarring, bleeding, and/or bruising at the injection site, pain, and infection. Scarring may occur as a result of repeated injections in a small area or by the acidity of some of the injection solutions. If scarring occurs and it goes unchecked, it can eventually cause the penis to bend abnormally and in worse case scenarios, can interrupt blood flow and nerve supply.

Patients must be carefully instructed in the method of penile injections so as to avoid complications. Start with a low dose of solution to avoid a priapism and work up to an acceptable baseline. Once this dose is established, time should be spent teaching the patient how to use a syringe and how to properly inject himself. We do not use auto-injectors at our clinic because if the device breaks if the patient forgets it when he goes on vacation, he would be unable to use the medication. Also, the patient needs to be able to "feel" where he is in the corpora to more accurately ensure that the medication is injected in the correct area. Poor injection technique not only decreases the success of the injection but can also increase the chance of scarring. Patients are taught aseptic technique for injections to decrease their chance of infection at the injection site. Also, firm pressure on the injection site after application will decrease the chance of penis bruising.

The patient is then sent home with predrawn test doses. This gives him a chance to try varying doses of the medication at home under more comfortable circumstances. When a successful dose is found, he returns to the office and is taught how to draw medication out of a closed vial system and instructed on long-term use and followup. Followup is required at 3 months and then every 6 months thereafter. This is done to perform a scar check. If patients do not return to the office for their scar checks, they are not allowed refills on their medication. In general, 75% of impotent men will have a good response to injection therapy (Govier et al., 1993; Kerfoot & Carson, 1991; Lakin et al.,1990; Linet & Ogrinc, 1996; Padma-Nathan, Goldstein, Payton, & Krane, 1987; Porst, 1996).

INTRAURETHRAL APPLICATIONS

MUSE®, the first intraurethral drug, was introduced in January of 1997 (see Figure 3). The active ingredient in MUSE is alprostadil which is the naturally occurring substance of prostaglandin. The drug, in a pellet form, is given through an applicator which is inserted into the end of the penis. The pellet is then absorbed through the urethral wall into the corpora, usually causing an erection 10 minutes after application. It comes in four doses: 125, 250, 500, and 1,000 mcG. This is a breakthrough system because it is simple to use and noninvasive. Candidates for this drug include those who have found the vacuum device ineffective or too cumbersome, patients who have failed injections because of pain, priapism, or fibrosis, or those who are not ready for invasiveness of either the injections or implants (described below). The company that produces MUSE also has developed its own ring, ActisD, which can be used with the medication to obtain and maintain a more rigid erection. It is different from other rings in that it is more of a lariat style than a closed band.

The drawbacks that have discouraged patients from using this medication include decreased spontaneity, burning of the urethra upon application, achiness similar to that of prostaglandin injections, possible light-headedness or syncope after application, erections that are not as rigid as those with injections, limited sexual positions, and cost of the medication. Nevertheless, this is not a drug that should be passed over. With patience and thorough teaching some men have benefited from this therapy.

PROTHESES

Implanted penile prostheses, first introduced more than 20 years ago, provided a gateway to research in the basic science of erectile function. This led to the development of the less invasive treatment modalities mentioned above. Penile implants have received some bad publicity, especially on radio and television talk shows which tend to stress the worse case scenarios of implants gone awry. However, they continue to maintain a fair share of the market as a viable treatment option.

The most popular model of all implants is the three-piece inflatable device (see Figure 4). The surgery is done as an outpatient procedure and the implant is placed through a small penile-scrotal incision. The implant consists of two cylinders that are placed within each corpora cavernosum, an inflate-deflate pump that sits under the skin in the scrotum, and a reservoir, filled with normal saline, that is tucked up into the retroperitoneal space. No corporeal tissue is removed during this procedure, and the penis appears normal after healing. Penile sensation, the ability to reach climax, and ejaculation remain intact. To inflate the device, the patient squeezes the pump in the scrotum, which forces fluid from the reservoir into the cylinders. They engorge, not only giving the rigidity of a normal erection, but also expanding to fill out the patient's normal girth of the penis. To deflate the device, a release button is activated and the fluid flows out of the cylinders and back into the reservoir, leaving the penis soft and flaccid.

As the implants have improved, their failure rate has decreased. Implants now come with a lifetime warranty, and life expectancy of the current devices are in the range of 7 to 10 years. A recent review of 146 devices placed at Virginia Mason Medical Center in Seattle showed that only 4.2% of the devices required revision due to mechanical malfunction after 1 to 8 years (Govier, 1996).

The satisfaction rate among penile implant patients is usually high, 80% to 90% (Govier, 1996; McLaren & Barrett, 1992). Men like the control they have of their erections with the prosthesis, when they can use it, how often they can use it, and control over the length of time the erection lasts. Many men are reluctant at first to hear about implants, but are surprised to find out that they are not as terrible as they had originally thought or heard.

Before implantation of a penile prosthesis, some important points must be stressed to the patient. First of all, once an implant always an implant. The smooth tissue in the corpora, that under normal conditions engorges when an erection occurs, is destroyed when it is dilated to allow room for placement of the cylinders. Many patients will want to try less invasive options before deciding to pursue an implant, but an implant should not be ruled out as a first choice. Second, infection can mean removal of the device. Third, the prosthesis is a mechanical device which can fail and the correction of the failed device requires another operation. The patient, and whenever possible the partner, should be informed about the type of prosthesis that will be put in, expectations for postoperative pain and activity, and how to operate the device for use.

NEW THERAPIES

As more and more information is gained on how the relaxation process takes place in the penis, more drugs are being developed to treat impotence. The most promising of these medications is an oral pill, ViagraD, produced by the Pfizer Corporation, and FDA approved in early April 1998. It is effective in treating both organic and psychological impotence (Boolell, et al., 1996). Sildenafil is the active chemical and it is a competitive and selective inhibitor of cyclic GMP. It acts on the specific type 5 phosphodiesterase (PDE), which then blocks the conversion of cyclic GMP to cyclic AMP, enhancing the erection. This PDE type 5 is present in the smooth muscle cells of the corpus cavernosum, blood vessels, and in circulating platelets. Patients are instructed to take the pill 1 hour prior to desired intercourse. Sexual stimulation must then be performed 1/2 to 1 hour after taking the pill to bring the erection on. If no stimulation occurs, nothing will happen. So, on one hand it takes a little planning if they are going to have intercourse, but the erection occurs much more naturally, making it more appealing to the patient and his partner. Patients should also be advised not to drink alcohol prior to sexual activity, since alcohol may impair his ability to have erections and potentially cause the treatment to be less effective. Side effects can include facial flushing, mild headaches, and GI distress, usually diarrhea. Reports of transient and mild disturbance of vision have been reported including a blue haze, increased "brightness" and acuity of vision. If taken more than once daily, symptoms of back and leg aches, nausea, vomiting, and diarrhea have occurred. The only reported drug contraindication is with nitrate medications. Viagra should not be administered to patients taking these drugs based on the sever potentiation of vasodilatory effects. Dosing should be started at 25 mg, and increased as needed to 50 mg and 100 mg. There has been a lot of press on this drug being used for women, but no trials have been done yet in the United States and little is understood on how it will react in females; thus it should not be prescribed for female patients. Two other oral medications awaiting FDA approval to treat impotence are VasomaxD and ApomorphineD.

Penile revascularization, venous ligation, and dorsal vein arterialization, performed with more frequency in the past, are now considered investigational surgeries and should be performed only in a research setting with long-term followup available.

OTHER CONSIDERATIONS

When discussing treatment options with the patient, involve the partner whenever possible. Explain that this will be a change in lifestyle for them. The patient will need to learn to accept that his impotence is a lifelong problem that cannot be cured by medications or treatments. A treatment choice, perhaps originally passed over by the patient and his partner because of the preconceived ideas about a particular treatment (invasiveness, side effects, quality of erection, cost, ability to climax), may be reconsidered if all aspects about the option are presented. A good outcome from the professional's perspective may not necessarily be satisfactory to either the patient or the partner. Not only does the treatment need to work successfully for them, but it needs to be accepted by both of them or it will not be used. Sometimes people choose to do nothing and that is also okay.

Whatever the situation, patients should be told that the intimacy between themselves and their partner should not be forgotten or put aside because the erection has failed. If there are long-standing problems in the relationship, an erection will not fix those problems. If the patient has not had a sexual closeness with his partner in a long time because of various reasons, one being impotence, it will not be brought back by the magic of an erection. Intimacy needs work by both partners. Closeness and cuddling may have to be relearned. And practice makes perfect.

REFERENCES

1. Boolell, M., Allen, M.J., Ballard, S.A., Gepi-Attee, S., Muirhead, G.J., Naylor, A.M., Osterloh, H. H., & Gingell, C. (1996). Sildenafil: A orally active type 5 cyclic GMP-specific phosphodiesterase inhibitor for the treatment of penile erectile dysfunction. International Journal of Impotence Research 8(2), 47-52.

2. Feldman, H.A., Goldstein, I., Hatzichristou, D.G., Krane, R.J., & McKinlay, J.B. (1994). Impotence and its medical and psychosocial correlates: Results of the Massachusetts male aging study. Journal of Urology, 151, 54-61.

3. Govier, F. (1996). Mechanical reliability and surgical complications of the three-piece inflatable penile prosthesis. World Impotence Journal, 8, 155. (Abstract No. D134).

4. Govier, F.E., McClure, R.D., & Kramer-Levien, D. (1996). Endocrine screening for sexual dysfunction using free testosterone determinations. Journal of Urology, 156, 405-408.

5. Govier, F.E., McClure, R.D., Weissman, R.M., Gibbons, R.P., Pritchett, T.R., & Kramer-Levien, D. (1993). Experience with triple-drug therapy in a pharmacological erection program. Journal of Urology, 150(6), 1822-1824.

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10. Linet, O.I., & Ogrinc, F.G. (1996). Efficacy and safety of intracavernosal alprostadil in men with erectile dysfunction. New England Journal of Medicine, 334, 873-877.

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