Penile prosthesis is surgically implanted into the corpus cavernosum of the penis. This can be an inflatable implant that can be pumped up to obtain an erection, or a pair of bendable rods. Implants are highly effective with a satisfaction rate of over 85%, but they are not reversible. This treatment is the best solution for patients with severe ED who have failed to respond to multiple forms of treatment. The only minor side effect of the surgery is infection which occurs is approximately 1-5% of patients.