Penile Prostheses for Erectile Dysfunction

Types and Mechanisms

Penile prostheses are mechanical devices implanted within the corpora cavernosa of the penis that provide rigidity for sexual intercourse in men with erectile dysfunction who have failed or cannot use less invasive treatments 1, 2
Malleable (non-inflatable) prostheses maintain a constant rigidity but can be bent into different positions, offering advantages of lower cost, better mechanical reliability, and ease of use without requiring patient training on inflation/deflation techniques 1, 3
Inflatable prostheses provide a more natural appearance in both flaccid and erect states, consisting of two-piece or three-piece designs that include cylinders, a pump mechanism, and a fluid reservoir placed in the abdomen 1, 2

Three-piece inflatable prostheses are the most common design, featuring paired cylinders implanted in the corpora cavernosa, a pump placed in the scrotum, and a fluid reservoir positioned in the abdomen 1, 4
Design improvements have reduced mechanical failure rates to 6-16% at 5 years, with modern devices featuring lockout valves to prevent auto-inflation and antibiotic or hydrophilic coatings to reduce infection risk (1-2% infection rates with coated models) 1, 5
Current devices are MRI-compatible at 1.5 Tesla field strength 1
Infection-inhibiting coatings have significantly reduced infection rates 5

Surgical implantation is essentially irreversible 6
Penile prosthesis implantation may result in penile shortening compared to natural erections 2
There is a potential for mechanical failure requiring reoperation 1
There is a risk of infection, though reduced with modern coated devices 1, 5
Penile prosthesis implantation should be considered for men with erectile dysfunction who have failed or cannot use less invasive treatments and have no active infections (systemic, cutaneous, or urinary tract) 4, 5
Thorough counseling should include types of prostheses available, possibility of complications, differences from natural erections, and potential reduction in effectiveness of other therapies if device removal is needed 1, 2, 6

The American Urological Association recommends malleable penile prostheses for their lower cost, better mechanical reliability, and ease of use without requiring patient training, with advantages including high technical success rates and patient satisfaction 7
The British Medical Association notes that inflatable penile prostheses provide a more natural appearance in both flaccid and erect states, with high technical success rates and patient satisfaction (80%) 8, 9
The use of modern designs featuring lockout valves can prevent auto-inflation, reducing rates from 11% to 1.3% 7

The incorporation of antibiotic coatings (rifampin and minocycline) has reduced infection rates from 1.61% to 0.68% 7
Hydrophilic coatings that can be immersed in antibiotics pre-operatively have reduced infection rates from 2.07% to 1.06% 7
Inflatable penile prostheses are recommended for patients with Peyronie's disease as they allow for modeling to maximize curvature correction, with a strength of evidence based on clinical experience 10
Patients must understand that prosthesis implantation will likely reduce the efficacy of subsequent therapies should they be needed, with a moderate level of evidence supporting this claim 7

For patients with acute ischemic priapism lasting >36 hours, penile prosthesis placement may be considered to provide detumescence and preserve penile length, based on limited evidence from case reports 11
Infection remains the most serious complication (rates now 1-2% with coated devices), with a high level of evidence supporting the use of coated devices to reduce infection rates 7
Other complications include erosion, migration, penile shortening, and changes in sensation, with a moderate level of evidence supporting the occurrence of these complications 8, 9