(132) Comparing the Frequencies of Different Species Present in Revision Penile Prostheses Surgery due to Infectious or Non-Infectious Causes

Introduction

Inflatable penile prosthesis (IPP) is a third-line treatment for treating erectile dysfunction in men. However, complications in the prostheses can cause the patient to undergo secondary penile prostheses (PP) surgery. Infection is a feared complication of IPP surgery and has a higher risk at secondary surgery. Next-generation sequencing (NGS) compares DNA to identify species and report relative abundances. NGS is an established method of microbial detection and identification in Orthopedics, Otolaryngology, wound care, and infectious disease. In prosthetic urology, NGS has been shown to provide better and more acute information than traditional cultures. Characterizing biofilm may allow for a better understanding of potential issues that could reduce IPP durability.

Objective

This study aims to identify the frequency of microbial species present in penile prostheses that needed revision surgery and compare the quantitative data between infectious etiology and mechanical failure cases. We hypothesize that, during secondary surgery, mechanical failure and clinically infected IPPs will display different frequencies of microbial species.

Methods

This study comprised 126 patients from 2 different centers that underwent revision PP surgery for either infectious or non-infectious issues. Upon entering the pump space (wiped pump/tubing/capsule) during surgery, 2 swabs specimens were collected and sent to the institutional laboratory for routine culture and the other to MicrogenDx for NGS testing. During the specimen evaluation, the frequency of microbial species in each specimen was recorded and sorted based on the reason for revision PP surgery. ANOVA was used to test effects of ethnicity, age, diabetes status, implant duration, and year of implant removal.

Results

The demographics of the 126 patients consisted of a median age of 69 (1st quartile= 61, 3rd quartile= 76), of which 84 were White, 41 were African American, and 1 was of unknown ethnicity. 104 patients (83%) needed revision PP surgery due to mechanical failure causes, and 22 patients (17%) needed revision PP surgery due to infectious causes. From the data collected and analyzed, the mechanical and infection specimens differed significantly in a few species. In the infection samples, E. coli, C. tuberculostearicum, and C. acnes were significantly underrepresented, and P. aeruginosa was significantly overrepresented compared to the mechanical samples (Figure 1). Asterisks denote these species in Figure 1.

Conclusions

NGS has been shown to accurately represent the characteristics of biofilm present in secondary PP surgery, supported by similar results in Ortho and ENT literature. When the PP was clinically infected, four microbial species experienced significant differences in expression frequency compared to mechanical failure IPPs. In addition, the NGS data collected contradicts the traditional theory that the coagulase-negative Staphylococcus species is the most present microbial species in PP biofilm, as we observed more prevalence of E. coli in the biofilm we analyzed.

Disclosure

Yes, this is sponsored by industry/sponsor: MicroGenDX.

Clarification: Industry funding only - investigator initiated and executed study.

Any of the authors act as a consultant, employee or shareholder of an industry for: MicroGenDX, Irrisept.