Mechanical vacuum devices
cause erection by creating a
partial vacuum, which draws
blood into the penis,
engorging and expanding it.
The devices have three
components: a plastic
cylinder, into which the
penis is placed; a pump,
which draws air out of the
cylinder; and an elastic
band, which is placed around
the base of the penis to
maintain the erection after
the cylinder is removed and
during intercourse by
preventing blood from
flowing back into the body .
One variation of the vacuum device involves a semirigid rubber sheath that is placed on the penis and remains there after erection is attained and during intercourse.
Surgery
Surgery usually has one of three goals:
to implant a device that can cause the penis to become erect
to reconstruct arteries to increase flow of blood to the penis
to block off veins that allow blood to leak from the penile tissues
Implanted devices, known as prostheses, can restore erection in many men with ED. Possible problems with implants include mechanical breakdown and infection, although mechanical problems have diminished in recent years because of technological advances.
Malleable implants usually consist of paired rods, which are inserted surgically into the corpora cavernosa. The user manually adjusts the position of the penis and, therefore, the rods. Adjustment does not affect the width or length of the penis.
Inflatable implants consist of paired cylinders, which are surgically inserted inside the penis and can be expanded using pressurized fluid (see figure 3). Tubes connect the cylinders to a fluid reservoir and a pump, which are also surgically implanted. The patient inflates the cylinders by pressing on the small pump, located under the skin in the scrotum. Inflatable implants can expand the length and width of the penis somewhat. They also leave the penis in a more natural state when not inflated.
Surgery to repair arteries can reduce ED caused by obstructions that block the flow of blood. The best candidates for such surgery are young men with discrete blockage of an artery because of an injury to the crotch or fracture of the pelvis. The procedure is almost never successful in older men with widespread blockage.
Surgery to veins that allow blood to leave the penis usually involves an opposite procedure—intentional blockage. Blocking off veins (ligation) can reduce the leakage of blood that diminishes the rigidity of the penis during erection. However, experts have raised questions about the long-term effectiveness of this procedure, and it is rarely done.
Advances in suppositories, injectable medications, implants, and vacuum devices have expanded the options for men seeking treatment for ED. These advances have also helped increase the number of men seeking treatment. Gene therapy for ED is now being tested in several centers and may offer a long-lasting therapeutic approach for ED.
The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) sponsors programs aimed at understanding the causes of erectile dysfunction and finding treatments to reverse its effects. NIDDK's Division of Kidney, Urologic, and Hematologic Diseases supported the researchers who developed Viagra and continue to support basic research into the mechanisms of erection and the diseases that impair normal function at the cellular and molecular levels, including diabetes and high blood pressure.