Penile Prostheses: Which Antibiotic Dipping Solutions are Most Effective in Men with Diabetes?
FIRST PUBLISHED: August 15, 2020 – The Journal of Sexual Medicine
Infection after penile prosthesis surgery is a common concern. However, the development of antibiotic coatings has reduced infection rates over time. In general, the rates range from 1% to 2%. In diabetic men, infection rates range from 2% to 3%.
The Coloplast Titan device uses a hydrophilic coating that surgeons may further customize by using an additional antibiotic agent. However, the best choice of antibiotics is a matter of debate.
This study compared different antibiotic dip regimens used with Coloplast Titan devices to prevent postoperative infection, explantation, and revision in men with diabetes.
Materials and Methods
A retrospective medical review was conducted for 932 men with diabetes who received primary inflatable penile prostheses (IPPs) for medication-refractory erectile dysfunction (ED) between April 2003 and August 2018. Implantation surgeries took place in 18 high surgical volume centers located in the United States, Belgium, Germany, and South Korea.
Of the entire group, 473 men received a Coloplast Titan implant device. The rest received an AMS device.
The study’s primary variables were antibiotic and antifungal dipping agents used immediately before implantation. Rates of infection, explantation, and revision were the study’s outcomes.
Findings are based on 468 Coloplast device recipients with an average age of 60.6 years.
The postoperative infection rate was 3.4%. The explantation rate was 4.1%, and the revision rate was 6.6%.
The most commonly used dipping solutions were:
- Vancomycin + gentamicin (59% of patients)
- Rifampin + gentamicin (30.6%)
- Trimethoprim/sulfamethoxazole + gentamicin (5.1%)
- Rifampin + bacitracin (3.2%)
- Polymyxin + bacitracin + gentamicin (2.1%)
One hundred ninety Coloplast implants were also dipped in an antifungal solution (amphotericin B) before implantation.
The vancomycin + gentamicin combination had a significantly lower postoperative infection rate (1.4%) compared to the other agents (6.3%).
Use of the other solutions was an independent predictor of postoperative infection after adjusting for age, body mass index, preoperative blood glucose level, and hemoglobin A1C.
Use of rifampin was linked to a higher number of infections, but this result was not quite significant.
Use of the antifungal solution made no difference in infection, explantation, or revision rates.
The combination of vancomycin + gentamicin was the most popular and most efficacious dipping solution for reducing postoperative infection, explantation, and revision in diabetic men.
“Vancomycin + gentamicin may work better as a coating element on the prosthesis than as systemic agents as their concentrations are maximal at the site of biofilm formation, which could explain why the infection rate was so low with that particular dipping solution.”
The combination of trimethoprim/sulfamethoxazole + gentamicin had the highest infection, explantation, and revision rates. It was unclear why this result occurred; however, the number of cases in the sample may have been “too small to draw concrete conclusions about its use in practice.”
The infection rate for implants dipped in the rifampin+ gentamicin combination was 5.6%, making the solution “almost a significant risk factor for postoperative infection.” However, this result is the opposite of what has been reported in previous literature. This might be explained by the “overuse” of rifampin, which may lead to bacterial resistance.
Several limitations were acknowledged:
- The study had a retrospective design.
- The length of time each device was immersed in the solutions was unknown.
- Surgeon skill and experience were unknown.
- There was a small number of infections.
- Only 10.5% of the patients had devices dipped in solutions that were not vancomycin or rifampin + gentamicin, so their effectiveness was not as clear.