The most important risks of the 3 piece penile implant are infection, device malfunction, implant erosion, surgical mishaps in the operating room and penile shortening. The two main penile implant brands are the AMS 700 and Coloplast Titan. They are equivalent in terms of quality, performance and risks.
Infection
Infection is the most important complication because once the implant becomes infected, it must be removed. The rate of implant infection is about 2%[1].
Antibiotics are useless against an infected implant. The reason antibiotics do not work is that once bacteria reach the implant, they secrete a slimy material called biofilm. Biofilm surrounds the implant and envelopes the bacteria. Biofilm prevents antibiotics from reaching the bacteria and also prevents the body’s immune system from killing the bacteria.
After the infected implant is removed, a new implant can be placed immediately so long as the implant infection is not severe. Before the new implant is inserted, the wound is washed with 7 different antibiotics solutions. This “salvage” procedure has an 82% success rate. If the implant infection is severe, than a new implant can be placed in 6 months.
To reduce the risk of infection, the AMS 700 inflatable implant is pre-coated with 2 antibiotics – rifampin and minocycline. This coating is called InhibiZone.
The Coloplast Titan also has a coating designed to prevent infection. This polymer coating accomplishes two things. First, it prevents bacteria from sticking to the surface of the implant. Second, the coating absorbs antibiotics. The surgeon, therefore, immerses the implant into an antibiotic solution right before he inserts the implant into the patient.
The Coloplast Titan and AMS 700 antibiotic coatings have succeeded in cutting the rate of implant infection in half[2].
Finally, a very important factor in preventing infection is choosing a penile surgeon in Brooklyn that performs a lot of penile implants. Studies show that high volume implant surgeons have 1/3 the rate of infection as compared to low volume implant surgeons[3].
Device Malfunction
About 70% of 3 piece penile implants will continue to work 15 years after the device is inserted[4]. This makes the 3 piece penile implant arguably the best mechanical device ever inserted in humans.
Device failure is most often due to leakage of fluid from either the cylinders, the tubing or the reservoir. Other problems include formation of a cylinder aneurysm or bubble, cylinder breakage, pump malfunction, and auto-inflation.
Once the device malfunctions the entire implant should be replaced. Before the new device is inserted, the urologist should perform a thorough washout of the wound to remove any biofilm. If washout is performed properly, the infection rate of the replaced device should be low.
Device malfunction has decreased largely due to improved device construction material. The Coloplast Titan is made of Bioflex which is similar to polyurethane. The AMS device is composed of silicone and a Dacron fabric. The AMS implant also has an outer covering of a polymer called Parylene. These materials have decreased the rate of device malfunction.
Erosion of the Implant
Erosion occurs when the device moves out of its proper position due to constant pressure against the surrounding tissue. The rate of erosion for the inflatable implant is about 3%[5] after 5 years. Erosion occurs less often with inflatable implants as compared to malleable implants – because the inflatable implant in the flaccid state does not press against the surrounding tissue.
If the device erodes outside of the penis, it is considered to be infected and the entire implant must be removed. After implant removal, it is best to wait several months before a new device is inserted. This delay allows the tissue to heal.
Mishaps in the Operating Room
Surgical mishaps include perforation of the corpora cavernosa, which are the cylinders in the penis that contain the implant, and injury to the urethra. Rarely, severe complications can occur when the reservoir is inserted next to the urinary bladder. These complications include injury to the small intestine and injury to the iliac artery or vein.
Dr. Lazare avoids the possibility of severe complications associated with reservoir placement. He accomplishes this with a new technique that involves placing the reservoir behind the wall of the abdomen rather than next to the urinary bladder. He utilizes a special new reservoir that has a flat shape similar to the shape of a pancake.
Decreased Penile Length and Girth
The erect penile length following penile implant surgery will decrease about ¼ of an inch, on the average[6]. It is important for the patient to have realistic expectations and to understand that the penile implant is not a penis enlarging procedure. With proper counseling, most patients view the slight loss in penile length as negligible and insignificant.
It is also important for the patient to understand that loss of penile length can also be due to the underlying disease process. The most important situations that can result in loss of penile length include radical prostatectomy for prostate cancer, priapism or prolonged erection, Peyronie’s disease or bent penis, and removal of an infected penile implant – which can result in penile scarring and shortening.
[1] Carson, C, Mulchahy, J, Harsch, M, Long- Term Infection Outcomes After Original Antibiotic Impregnated Inflatable Penile Prosthesis Implants:Up to 7.7 Years of Followup, The Journal Of Urology, Vol. 185, 614-618, Frebruary 2011
[2] Dhabuwala, C, Sheth, S, Zamzow, B, Infection Rates of Rifampin/Gentamycin Coated Titan Coloplast Penile Implants. Comparison With InhibiZone Impregnated AMS Penile Implants, Journal of Sexual Medicine, 2011, 8, 315-320
[3] Onyeji, Sui, W, Pagano, M, Weinberg, A, James, M, Theofanides, M, Stember, D, Anderson, C and Stahl, P, Impact of Surgeon Case Volume On Reoperation Rates After Inflatable Penis Prosthesis Surgery, Journal of Urology, Volume 197, 223-229, January 2017
[4] Wilson, S, Delk, J, Salem, E, Cleves, M, Long Term Survival of Inflatable Penile Prostheses: Single Surgical Group Experience with 2,384 First Time Implants Spanning Two Decades, Journal of Sexual Medicine, 2007, 4, 1074-1079
[5] Minervini, A, Ralph, D, Pryor, J, Outcome of Penile Prosthesis Implantation For Treating Erectile Dysfunction: Experience With 504 Procedures, British Journal of Urology, 97, 129-133, 2005
[6] Wang, R, Howard, G, Hoang, A, Yuan, JH, Lin, HC, Dai, YT, Prospective and Long Term Evaluation of Erect Penile Length Obtained with Inflatable Penile Prosthesis to That Induced by Intracavernosal Injection, Asian Journal of Andrology, 2009, 11, 411 – 415