Using a tiny needle and syringe, the man injects a small amount of medicine into the side of his penis. The medicine relaxes the blood vessels, allowing blood to flow into the penis. This treatment has been widely used and accepted since the early 1980s. The three most common medicines are prostaglandin E1 (alprostadil), papaverine (Papacon®), and phentolamine (Regitine®).
Penis pumps produce erections by drawing blood, via air suction, into the penis. The devices consist of a cylindrical tube, 12 to 18 inches long, connected by a small air hose to a hand pump (on many models this resembles the squeeze mechanism on a blood pressure monitor). Users place the tube over the penis then pump to produce an erection. They must then place an elastic band around the base of the penis to keep the blood there and maintain the erection.
Organic ED involves abnormalities the penile arteries, veins, or both and is the most common cause of ED, especially in older men. When the problem is arterial, it is usually caused by arteriosclerosis, or hardening of the arteries, although trauma to the arteries may be the cause. The controllable risk factors for arteriosclerosis--being overweight, lack of exercise, high cholesterol, high blood pressure, and cigarette smoking--can cause erectile failure often before progressing to affect the heart.
Trauma to the pelvic blood vessels or nerves can also lead result in ED. Bicycle riding for long periods has been implicated as an etiologic factor; direct compression of the perineum by the bicycle seat may cause vascular and nerve injury.  On the other hand, bicycling for less than 3 hours per week may be somewhat protective against ED.  Some of the newer bicycle seats have been designed to diminish pressure on the perineum. [37, 38]
When lifestyle changes alone don’t work, drug therapy (Viagra®, Cialis®, Levitra®, etc.) is normally the next step. Most of these medications work similarly to enhance a natural chemical in your body that relaxes the muscles in your penis. The goal of this medication is to increase your response to sexual stimulation by increasing the blood flow in your penis allowing you to get an erection.22
"The good news is, our study also found that a large proportion of men were naturally overcoming erectile dysfunction issues. The remission rate of those with erectile dysfunction was 29%, which is very high. This shows that many of these factors affecting men are modifiable, offering them an opportunity to do something about their condition," Professor Wittert says.
The sympathetic pathway originates from the 11th thoracic to the 2nd lumbar spinal segments and goes via the white rami to enter the sympathetic chain ganglia. Subsequently nerves travel through the lumbar splanchnic to inferior mesenteric and superior hypogastric nerves to the pelvic plexus. The T10 through T12 segments are most often the origin of sympathetic fibers, and the sympathetic chain ganglia that innervate the penis are located in the sacral and caudal ganglia (3).
Alprostadil is injected into the side of penis with a very fine needle. It's of great value to have the first shot in the doctor's office before doing this on your own. Self-injection lessons should be given in your doctor's office by an experienced professional. The success rate for getting an erection firm enough to have sex is as high as 85% with this treatment. Many men who do not respond to oral PDE5 inhibitors can be ‘rescued' with ICI.