Timing and causative organisms associated with modern inflatable penile prosthesis infection: an institutional retrospective
Authors: Bole MD Raevti , Habashy MD Engy , Yang MD David , Ahmed MBBCh Mohamed , Trost MD Landon , Ziegelmann MD Matthew , Helo MD Sevann , Kohler MD Tobias 
Published: January 2023

Background

The advent of antibiotic-coated devices has reduced the rate of inflatable penile prosthesis (IPP) infections; however, this may have altered microbial profiles when infections do occur.

Aim

To describe the timing and causative organisms behind infection of infection retardant–coated IPPs in the context of our institution’s perioperative antimicrobial protocols.

Methods

We retrospectively reviewed all patients undergoing IPP placement at our institution from January 2014 to January 2022. In all patients, perioperative antibiotic administration was congruent with American Urological Association guidelines. Boston Scientific devices are impregnated with InhibiZone (rifampin and minocycline), and all Coloplast devices were soaked in rifampin and gentamicin. Intraoperative irrigation was performed with betadine 5% irrigation prior to November 2016 and with vancomycin-gentamicin solution afterward. Cases involving prosthesis infection were identified, and variables were extracted from the medical record. Descriptive and comparative statistics were tabulated to identify clinical characteristics, including patient comorbidities, prophylaxis regimen, symptom onset, and intraoperative culture result. We previously reported an increased infection risk with Betadine irrigation and stratified results accordingly.

Outcomes

The primary outcome was time to infectious symptoms, while the secondary outcome was description of device cultures at the time of explantation.

Results

A total of 1071 patients underwent IPP placement over 8 years with an overall infection rate of 2.6% (28/1071). After discontinuation of Betadine, the overall infection rate was significantly lower at 0.9% (8/919) with a relative risk of 16.9 with Betadine (P &lt; .0001). Primary procedures represented 46.4% (13/28). Of 28 patients with infection, only 1 had no identified risk factors; the remainder included Betadine at 71% (20/28), revision/salvage procedure at 53.6% (15/28), and diabetes at 50% (14/28). Median time to symptoms was 36 days (IQR, 26-52); almost 30% of patients had systemic symptoms. Organisms with high virulence, or ability to cause disease, were found in 90.5% (19/21) of positive cultures.

Clinical Implications

Our study revealed a median time to symptoms of just over 1 month. Risk factors for infection were Betadine 5% irrigation, diabetes, and revision/salvage cases. Over 90% causative organisms were virulent, demonstrating a microbial profile trend since antibiotic coating development.

Strengths and Limitations

The large prospectively maintained database is a strength along with the ability to follow specific changes in perioperative protocols. The retrospective nature of the study is a limitation as well as the low infection rate, which limits certain subanalyses from being performed.

Conclusion

IPP infections present in a delayed manner despite the rising virulence of infecting organisms. These findings highlight areas for improvement in perioperative protocols in the contemporary prosthetics era.