What is a penile prosthesis?
A penile prosthesis is an artificial device that, when placed in the penis, allows a man to have an erection. The development and use of penile prostheses began in the 1970s. Since then, numerous revisions and modifications in the prostheses have improved the satisfaction rate and mechanical durability of these devices.
The most commonly used is the three-piece prosthesis, which is comprised of two cylinders, a scrotal pump, and a separate reservoir that is placed in the pelvis (Figure 36). The advantage of the three-piece unit is that it allows for the maximal amount of fluid transfer given the larger reservoir size. Also, when placed correctly, the device and its tubing are completely concealed, so one is able to void in the locker room without anyone knowing that the multipart prosthesis is present. Multipart inflatable prostheses are made by American Medical Systems. Semirigid prostheses, although less popular, have less risk of mechanical problems (Figure 37). The semirigid prosthesis does not change in size, rather one simply bends the penis up or down for participation in intercourse.
Figure 36. Three-piece penile prosthesis.
Drawing of AMS 700CX™/CKM™ Penile Prosthesis courtesy of American Medical Systems, Inc., Minnetonka, MN (visitAMS.com).
Figure 37. One piece, semi-rigid penile prosthesis.
Placement of a penile prosthesis requires extensive patient and partner discussion. It is not considered a first-line therapy in most cases of ED, but is an appropriate therapy for well-counseled individuals who have not responded to other therapies or who have found those alternatives to be unsatisfactory.
Who is a candidate for a penile prosthesis?
Penile prostheses are usually placed in men with organic ED. In men with psychogenic erectile dysfunction, extensive counseling should be administered and other treatment options should be exhausted before a penile prosthesis is considered. For all other patients, extensive patient and partner counseling should take place before placement of a prosthesis; the expectations, indications, and risks need to be discussed clearly, as well as other currently available and future options.
A penile prosthesis is rarely the first-line therapy for ED. In my practice, when I discuss penile prostheses with patients, I equate the procedure for its surgical placement with crossing over a rickety bridge that collapses once the prosthesis is implanted. You cannot go backward once the prosthesis is placed; if it is removed because of infection, malfunction, or dissatisfaction, other options of treatment are unlikely to work. Although there have been reports of the vacuum device and injection therapy working in some individuals after removal of a prosthesis, these instances are not common. For all these reasons, it is best to try all available therapies and determine whether they are successful and satisfactory before placement of a prosthesis occurs.
Indications for a penile prosthesis include the following:
• The patient's unwillingness to consider, failure to respond to, or inability to continue with other forms of treatment, such as oral therapy, injection therapy, MUSE, and the vacuum device
• Postinjection therapy penile fibrosis
• Peyronie's disease and erectile dysfunction
• Postpriapism erectile dysfunction
• Sex-change operations in women who undergo surgical creation of a penis
• Penile amputations in men, who then undergo surgical creation of a penis
• Psychogenic erectile dysfunction, after extensive counseling and evaluation
• Neurogenic bladders requiring condom catheters for urinary drainage