What happens under normal conditions?
The internal structure of the penis includes two cylinder-shaped chambers, the corpora cavernosa. Filled with spongy tissue containing smooth muscles, fibrous tissue, veins and arteries, these chambers run the length of the organ and are surrounded by a membrane cover, called the tunica albuginea. The urethra, the channel through which urine and semen exit the body, is located on the underside of the corpora cavernosa and is surrounded by spongy tissue. The longest part of the penis is the shaft, which ends in the glans. The meatus is the opening at the end of the urethra.
Erection is the culmination of a complex set of physical, sensory and mental events, involving both the nervous and vascular systems. It begins when physical or psychological stimulation (arousal) causes neurotransmitters or impulses in the brain (chemicals such as dopamine, acetylcholine and nitric oxide) to tell the muscles of the corpora cavernosa to relax, allowing blood to fill the organ's tiny open spaces. As the tunica's fibrous or elastic tissues trap the blood, the penis engorges, or increases, in an erection. When stimulation finally ends, usually after ejaculation, pressure inside the organ decreases, as the muscles contract. Blood then flows from the penis and the penis returns to its normal shape and size.
What is erectile dysfunction (ED)?
Erectile dysfunction refers to the inability of a man to attain and maintain an erection sufficient for intercourse. It occurs when there is reduced blood flow to the penis or nerve damage, both of which can be triggered by a variety of factors. Scientists once believed that ED was an emotional issue alone. But today they know that physical factors are just as important as psychological triggers—stress, marital/family discord, job instability, depression and performance anxiety—in provoking this problem. It is important to note that hundreds of medications can also contribute to impotence while they fight allergic reactions, high blood pressure, ulcers, fungal infections, anxiety, depression and psychoses.
Who is at risk for erectile dysfunction (ED)?
A man is at risk if they suffer from:
Vascular diseases: Hardening or narrowing of arteries, often associated with high cholesterol, can also restrict blood flow to the penis, particularly if you are over 60. Because smoking can lead to any of the factors responsible for vascular problems—such as high blood pressure—it is probably an important factor in both arterial disease (atherosclerosis) and ED.
Neurologic disorders: Spinal cord diseases or injuries, brain injuries, multiple sclerosis, Parkinson's disease and other progressive diseases can interrupt nerve impulses to and from the brain. Diabetes poses both neurological and vascular problems because it damages small blood vessels and nerves throughout the body, impairing the impulses and blood flow necessary for an erection.
Other conditions/illnesses: In addition, other chronic illnesses such as cancer and well as hormonal imbalances and penile disorders can disrupt the nerve impulses and blood flow necessary for normal erections.
What are the symptoms of erectile dysfunction (ED)?
Failing to achieve and/or sustain an erection is the primary sign of ED. But diagnosing the specific cause and prescribing appropriate treatment usually require a variety of tests, beginning with a complete history and physical examination.
Your doctor may order additional laboratory tests to assess any conditions that may be interfering with normal erectile function, particularly arterial flow to the penis. A blood test, for instance, is normally used to reveal blood lipids and triglycerides, both of which indicate atherosclerosis if elevated. A urinalysis identifies protein and glucose levels that can suggest diabetes.
While these analyses focus on your chemical status, erectile function tests are the principal tools your doctor will use to tell how the blood vessels, nerves, muscles and other tissues of your penis and pelvic region are working. Among them, penile nerve function tests—squeezing the head of the penis and measuring various responses—can determine if there is sufficient sensation in the penis. Nocturnal penile tumescence (NPT), or healthy involuntary erections during sleep, may rule out psychological issues and instead suggest nerve function or blood supply problems.
An imaging technique called duplex ultrasound may also be used. It monitors the behavior of moving structures and might provide some of the best data since it can evaluate blood flow, vein leaks, scarring of erectile tissue and some signs of atherosclerosis. During the test, an erection may be produced by injecting the stimulator prostaglandin into the body and then measuring vessel expansion and penile blood pressures, both of which are compared to the limp penis. In either case, duplex ultrasound can illustrate a specific blood vessel disease that may rule out a need for vascular surgery.
How is erectile dysfunction (ED) surgically treated?
The past several decades have ushered in a new treatment era for ED. Because of the advent of many advances, today urologists are helping millions of impotent men perform better and longer.
Penile prostheses: Surgically implanted devices to ensure stiffness have become highly reliable therapeutic solutions. Vacuum erection devices have proven to be safe alternatives in stiffening the penis by drawing blood into the organ with a pump and holding it with an "occluding band." Penile injection therapy is a relatively quick and effective way to send vasoactive drugs directly into the corpora cavernosa where they expand the vessels, relax the tissue and increase blood flow for an erection. Furthermore, the pills: sildenafil, tadalafil and vardenafil have become the treatments of choice for millions of men who have experienced the drugs' ability to boost levels of cyclic guanosine monophosphate (cGMP), a chemical factor in metabolism responsible for relaxing blood vessels.
Vascular surgery: Although options are varied, not everything is for everyone. In fact, two vascular approaches developed over past decades to restore penile blood flow disrupted by disease or traumas are useful for only a select few.
Penile arterial revascularization: This procedure is designed to keep blood flowing by rerouting it around a blocked or injured vessel. Indicated only for young men (under 45) with no known risk factors for atherosclerosis, this procedure is aimed at correcting any vessel injury at the base of the penis caused by adverse events such as blunt trauma or pelvic fracture. When such an event leaves a penile vessel too injured or blocked to transfer blood, the surgeon may microscopically connect a nearby artery to get around the site, clearing the pathway so enough blood can be supplied to the penis to enable an erection.
Venous ligation surgery: This procedure focuses on binding leaky penile vessels that are causing penile rigidity to diminish during erection. Because venous occlusion, necessary for sufficient firmness, depends on arterial blood flow and relaxation of the spongy tissue in the penis, this approach is designed to intentionally block off problematic veins so that there is enough blood trapped in the penis to create an appropriate erection. Since long-term success rates are less than 50 percent, this technique is rarely a choice for correcting ED.
In fact, you are not a candidate for either penile vascular surgery if you have insulin-dependent diabetes or widespread atherosclerosis. You are also not suited if you still use tobacco or experience consistently high blood serum cholesterol levels. Neither of these surgeries will work if you have injured nerves or diseased and/or generalized damaged blood vessels. Also, if you are a candidate, be aware that vascular surgeries are still considered experimental by some urologists and may also not be covered by your insurance.
What can be expected after surgical treatment for erectile dysfunction (ED)?
Most of the best known treatments for ED have excellent track records for being both effective and safe. But in making your choice, make sure to discuss the potential complications of each option with your doctor.
For instance, the good news about a penile prosthesis is that it does not usually affect urination, sex drive, orgasm or ejaculation. But on rare occasions, these semi-rigid, silicone-covered metal rods or hydraulic devices can cause pain or reduced sensation. While injections can initiate erections within 15 minutes to several hours, be aware that they also can produce prolonged or painful ones, not to mention a scarring of penile connective tissue (fibrosis).
At the same time, a vacuum erection device should take only one to three minutes to give an erection, usually with no serious side effects if used properly. However, the use of the erection device to maintain the erection is limited to 30 minutes.
Sildenafil, tadalafil and vardenafil have 75 percent success rates, primarily because they are a subtle solution that works within the hour. But on rare occasions they can cause headaches, flushing, indigestion or muscle aches. Also, if you have heart disease or low blood pressure, the Food and Drug Administration (FDA) cautions a thorough examination before getting a prescription. You cannot take these drugs if you are taking nitroglycerine or any similar drug.
Penile arterial revascularization can restore function in men, although only a small percentage of them undergo the procedure. While few patients experience postoperative complications, side effects can include penile scarring, numbness and shortening all of which can cause further impotence.
Venous ligation surgery, although rare, is also known to cause penile shortening, along with other problems. Also, improvements with venous ligation surgery may be temporary.
Frequently asked questions:
When is venous surgery for erectile dysfunction successful?
It has been most successful in young men with abnormally draining veins since birth who have never had a full erection. It has also been used in some patients with an injury to the covering tunica albuginea or the corpora cavernosa.
I am interested in vascular surgery, what should I be aware of?
Realize this is not a surgery for everyone. If you meet the criteria mentioned previously, you will want to find a specialist with a track record of having done these microsurgical techniques. Be aware, however, that penile vascular solutions are still experimental; few specialized urologists or vascular surgeons are trained to do either procedure. If your doctor is not one of them, you will need to ask for a referral. You will also want to get a second opinion if this treatment option is recommended, given that there are few patients who are good candidates.
If I choose vascular surgery, what should I ask my surgeon?
Once you have found a surgeon, ask about his or her experience and outcome record with penile arterial revascularization. Make sure that you understand the potential outcomes and possible complications. Also, ask how the particular approach stacks up against other treatment choices for you. For instance, vacuum devices and oral or injection therapies still work for some people. Penile prostheses, the most widely used surgical technique for ED, usually have a more favorable outcome than vascular techniques.
Is age a factor in impotence?
Yes. Data suggest that while not an inevitable part of aging, the risk of impotence increases as we grow older. About 5 percent of men at age 40 complain of the problem, while between 15 and 25 percent at age 65 experience it. Some experts suggest the numbers may be underreported since men are still embarrassed by this physical and psychological issue. However, the reassuring news is that it is treatable in all age groups
What should I remember about erectile dysfunction?
Also called impotence, ED is the consistent inability to sustain and maintain an erection, is a widespread problem. It may affect as many as 50 percent of men between ages 40 and 70. Luckily, doctors can identify physical causes involving blood flow, nerves or other mechanical issues involving the penis, which can also be addressed with modern technology. In fact, oral drugs, vacuum devices, injectable medications, psychotherapy and even surgery have made impotence very treatable. The promising news is that new drugs are sure to join existing non-invasive treatments while other experimental options, such as gene therapy, are on the horizon. In addition, ongoing modifications of today's standard treatments will eventually improve the picture for impotent men.