Experience with Prophylactic Gentamicin During Penile Prosthesis Surgery: A Retrospective Comparison of Two Different Doses

Abstract

Background Gentamicin has been determined to be active against a wide range of bacterial infections and has been commonly used as a preoperative antibiotic for inflatable penile prosthesis (IPP) implantation. However, the best dosing regimen to produce the safest optimal prophylactic effect remains to be determined. Aim To compare low- and high-dose gentamicin as prophylaxis during IPP implantation. Methods We retrospectively analyzed two groups of patients who underwent IPP placement from April 14, 2012 through April 13, 2016. Group 1 was composed of 490 patients who underwent IPP placement from April 14, 2012 through April 13, 2014 and received a low dose of preoperative gentamicin at 80 mg every 8 hours for 1 day. Group 2 was composed of 407 patients who underwent IPP placement from April 14, 2014 through April 13, 2016 and received a single high dose of preoperative gentamicin at 5 mg/kg. We compared the infection rates of IPP and any gentamicin-related toxicities. The same surgeon performed all procedures. All patients received additional vancomycin 1 g before incision and at 12 hours postoperatively. Outcome Demographic data and IPP infection rate were compared and potential toxicities from the higher dose of gentamicin were closely monitored. Results There were no significant differences in mean age, mean body mass index, and mean interval for IPP placement and IPP infection between the two groups. No toxicity was seen with the higher gentamicin dose. Six cases in group 1 (five de novo cases and one redo case, infection rate = 1.22%) and three cases in group 2 (two de novo cases and one redo case, infection rate = 0.74%) were found to have IPP infection. The infection rate in group 2 appeared to be lower than that in group 1, although a significant statistical difference was not achieved (P = .057). Clinical Implications These findings would help guide urologists in choosing an optimal preoperative gentamicin dose for IPP surgery. Strengths and Limitations This is the first study to report on the usage of high-dose preoperative gentamicin for IPP surgery but with limitations as a retrospective study. Conclusions Although not achieving a statistical difference, there was a trend for patients receiving a higher dose of preoperative gentamicin to have a lower IPP infection rate. No toxicity was encountered from the 5-mg/kg gentamicin dose. We recommend following prophylactic high-dose gentamicin guidelines.

AUA-recommended Antibiotic Prophylaxis for Primary Penile Implantation Results in a Higher, Not Lower, Risk for Postoperative Infection: A Multicenter Analysis

“…Xie et al reported no difference in toxicity in a comparative analysis of over 800 patients receiving low-dose (80 mg) vs weight-based dosing of gentamicin. 15 There was a higher incidence of infection in the low-dose gentamicin group (1.22% vs 0.74%), although this was not significant. The optimal dosing of gentamicin remains unclear but our series was unable to demonstrate a difference between groups.…”

Treatment of Penile Prosthesis Implant’s Infection

“…Among all the risk factors, the most important ones seem to be, without doubt, the presence of diabetes mellitus and the reintervention (defined as a change of penile prosthesis): in fact, while the incidence of infection after de novo implant is found only in 1–3% of the patients, in cases of revision surgery, the risk increases to 10% and in diabetic patients, it has even been reported to reach 18% [5]. Many of the selected articles addressed the prevention of PPI, but there is no clear consensus worldwide on certain topics, including the use of antibiotic therapy: about this topic, the 2 most relevant studies [6, 7] suggested that higher doses of gentamicin act as a protective factor; however, no significant association was found.…”

Report of Three Cases of AKI Following Weight-Based Gentamicin Prophylaxis for IPP Implantation: Potential Concerns for Patients with Preexisting Conditions

“…A recent retrospective study comparing weight-based to nonweight-based gentamicin dosing in inflatable penile prosthesis (IPP) implantation found no difference in the rate of postoperative acute kidney injury (AKI) [3]. However, the study was limited by the lack of any postoperative measures of nephrotoxicity and only evaluated rates of readmission for AKI.…”