PENILE PROSTHESES

Penile prostheses are semi-rigid or inflatable devices that are implanted into penises to alleviate impotence. The penis is composed of one channel for urine and semen, and three compartments with tough, fibrous walls containing erectile tissue. With appropriate stimulation, the blood vessels that lead out of these compartments constrict, trapping blood. Blood pressure fills and hardens the compartments producing an erection of sufficient firmness to perform sexual intercourse. Additional stimulation leads to ejaculation, where semen is pumped out of the urethra. When this system fails, erectile dysfunction or impotence (failure to create and maintain an erection) occurs. Impotence can be caused by a number of conditions, including diabetes, spinal cord injury, prolonged drug abuse, and removal of the prostate gland. If the medical condition is irreversible, a penile prosthesis may be considered. Men whose impotence is caused by psychological problems are not recommended for implant surgery.

Recently, it has been reported that surgeons insert approximately 20,000 penile implants into American men yearly. The most common device is a multi-component inflatable implant (approximately 45% of all implants). Semi-rigid rods account for about 35% of the implants. Self-contained devices comprise approximately 20% of implants.

Penile implant surgery is conducted on persons who have exhausted all other areas of treatment. Semi-rigid devices consist of two rods that are easier and less expensive to implant than the inflatable cylinders. Once implanted, the semi-rigid device needs no follow-up adjustments; however, it produces a penis that constantly remains semi-erect. Inflatable cylinders produce a more natural effect. Men using them are able to simulate an erection via a pump located in the scrotum.

With a surgical patient under general anesthesia, the device is inserted into the erectile tissue of the penis through an incision in the fibrous wall. In order to insert the pump for the inflatable implant, incisions are made in the abdomen and the perineum (area between the anus and the genitals). A fluid reservoir is placed into the groin, and the pump is placed in the scrotum. The cylinders, reservoir, and pump are connected by tubes and tested before the incisions are closed.

Diagnosis / Preparation
Surgery always requires a patient who is adequately informed about the procedure’s risks and benefits. The sexual partner should also be involved in the discussion. Prior to surgery, the region undergoes antibacterial cleansing and is shaved.

Aftercare
To minimize swelling, ice packs are applied to the penis for the first 24 hours following surgery. The incision sites are cleansed daily to prevent infection. Pain relievers may be taken.

Risks
With any implant, there is a slightly greater risk of infection than with simple surgery. The implant may irritate the penis and cause continuous pain. The inflatable prosthesis may need follow-up surgery to repair leaks in the reservoir or to reconnect the tubing.

Normal results
Successful implantation of a penile prosthesis solves some problems related to impotence. After healing from the surgical procedure, men with a penile prosthesis can resume normal sexual activities.

Morbidity and mortality rates
On a purely technical basis, morbidity associated with a surgically implanted penile implants is relatively uncommon, and is usually due to a post-surgical infection or to mechanical failure of the implanted device. Experts feel that personal dissatisfaction with a penile implant procedure is more common, and is usually due to unreasonable or inappropriate expectations for the procedure. Mortality is quite rare.

Alternatives
Medication (sildenafil citrate [Viagra]) is useful for some men with erectile dysfunction. The medication must be prescribed and monitored by a physician. Impotence caused psychological factors can usually be treated with appropriate counseling and therapy. Creams are available for purchase. Most experts agree that these cannot reverse physiological impotence. Most experts consider mechanical rings that prevent blood flow out of a penis to be dangerous, and advise against their use.