Penile Implant (Penile Prosthesis) for Treatment of ED and Peyronie’s Disease
For patients with Peyronie’s disease a number of treatments are available. For those men who have Peyronie’s disease and also develop ED (erectile dysfunction) or impotence, the standard treatments for Peyronie’s disease and ED can be tried.
Most men with Peyronie’s disease who have ED do not respond well to typical treatments for ED. Typically, the most effective treatment for men with Peyronie’s and ED is an inflatable penile prosthesis or penile implant (IPP). It treats both ED and Peyronies at the same time. Intra-operative maneuvers such as plaque excision with patching or penile remodeling may be used to address severe penile deformity caused by Peyronies disease.
Penile Prosthesis for Erectile Dysfunction Associated with Peyronie’s Disease
Penile prosthesis is a treatment option for men with erectile dysfunction. Usually penile prosthesis is implanted in men with moderate to severe erectile dysfunction that is accompanied by moderate to severe Peyronie’s disease. Penile prosthesis allows one to achieve a good erection for sexual intercourse. Implants are placed surgically. Many types of prostheses are available. Anybody undergoing penile prosthetic implant surgery should be made aware of the types of prosthesis available, their efficacy and potential complications in order to have realistic expectations.
Modern penile prostheses come in two types and include malleable and inflatable penile prosthesis.
The malleable prosthesis is made of a malleable metallic core covered with silicone rubber. Its main advantage is ease of use and minimal chances of mechanical failure. The disadvantage of malleable prosthesis is persistent rigidity of penis and risk of erosion.
The inflatable prosthesis works on the principle of hydraulics and is either two-piece or three-piece depending on the number of cylinders and reservoir. The cylinders are implanted in the corpora cavernosa and their distension produces penile rigidity. These cylinders are attached to a pump containing fluid, which is implanted in the scrotum. Squeezing this pump transfers a small amount of fluid from rear tip reservoir into the central chamber of cylinders and produces erection. When these cylinders are deflated, the central chamber in the cylinders collapses partially resulting in flaccidity. A two piece device is slightly easier to implant surgically in comparison to a three piece device that requires the placement of a reservoir. There is a small risk of mechanical failure with inflatable devices.
The most commonly used prosthesis is a three-piece implant that is inflatable though the malleable implant is more durable. The newer inflatable devices demonstrate good long term durability and high satisfaction. It consists of two longitudinal cylinders that are implanted in the penile shaft, a pump that is placed in the scrotum and a fluid containing reservoir that is implanted in the suprapubic area.
An ideal prosthesis should be able to provide a near normal penile flaccidity as well as erection. This is possible only with a three piece device as it is capable of transferring a large volume of fluid into the penile cylinders during an erection. This fluid goes back to the reservoir and results in almost normal appearing flaccidity.
It should be explained to the candidate that an inflatable prosthesis causes erection by increasing girth and not the length, therefore the erection appears shorter than a normal physiological erection which involves both increase in girth and length.
The durability of inflatable implants is 10 to 15 years and after this period it may require a replacement. In about 5 to 15% cases the implant has been reported to fail within 5 years.
Appropriate selection of patients results in a high satisfaction rate for a 3-piece inflatable device and may be in the range of 90%.
The glans penis does not undergo erection after prosthesis placement; therefore the size of erection becomes shorter. A preoperative method of assessment is to measure the length of stretched flaccid penis to have a realistic expectation.
“AMS 700 LGX cylinders” is an inflatable penile implant that can provide an additional elongation of 1 to 3 cm of penile length in appropriately selected patients.
The possible complications include infection, mechanical failure, leaks, persistent penile pain, shortening of penis and accidental autoinflation. Recently, antibiotic coated implants have been used which are associated with a very low infection rate of less than 1%.
Persistent penile pain may be associated with placement of a larger implant.
Risk of infection should be minimized by taking certain precautions during surgery. These include treatment of any pre-existing UTI, treating any other source of infection in body, giving antibiotics before and after surgery and use of antibiotics in the solution used for irrigation of the surgical site.
Infection is a dreaded complication that may require removal of the implant. This may be followed by worse scarring. Reimplantation thereafter becomes much more difficult. In people with UTI or local skin infection, this surgical procedure is delayed until resolution of the infection. Even the shaving of the operative area is done just before surgery and not a day before, so as to prevent bacterial colonization of any accidental skin cuts.
Erosion of the implant through skin or into the urethra also requires its removal.
If the erection is accompanied with penile curvature with angulation more than 60°, or there is an hourglass constriction, the preferable treatment requires plaque incision and graft placement.
In a person with both Peyronie’s disease and erectile dysfunction, both the problems should be addressed simultaneously. An inflatable device is considered in patients who have poor sexual function even after sildenafil therapy. The plaque should be stable before such a surgical procedure. This procedure minimizes penile shortening in these patients while maintaining penile straightening and rigidity.
Recent developments in penile implants includes hydrophilic coated devices, valve aided devices to prevent auto-inflation and implants with more efficient pump. The hydrophilic coated device reduces bacterial adhesion to the implant and absorbs the antibiotic in which it is dipped just before placement in the penis.
The outcome of a surgical procedure is judged on the basis of improvement in penile curvature and plaque and a satisfactory sexual experience by the patient. Coitus is usually possible 4 to 6 weeks after placement of an implant.
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