(705) Does Extending Postoperative Antibiotic Prophylaxis Reduce Penile Prosthesis Infection? A Retrospective Institutional Analysis

Introduction Erectile dysfunction (ED) is a prevalent condition with a significant impact on the quality of life of patients and their partners. For men with ED refractory to pharmacological therapy or when these are contraindicated, penile prosthesis implantation is indicated. Despite technological and surgical improvements, prosthesis infection remains a dreaded complication, with reported rates of 1–3% in high-volume centers. While perioperative antibiotic prophylaxis is universally accepted, the role of prolonged postoperative antibiotic therapy (>24 h) remains controversial. Objective To assess whether extended postoperative antibiotic prophylaxis confers any benefit in reducing prosthesis infection. Methods We conducted a retrospective review of all patients who underwent penile prosthesis implantation at our institution in the past ten years. Demographic, clinical, and perioperative variables were collected. Primary outcome was prosthesis infection requiring intravenous antibiotics or device explantation. Statistical analysis included Student’s t-test or Mann–Whitney U for continuous variables, chi-square or Fisher’s exact test for categorical variables, and multivariate logistic regression to identify independent predictors of infection. Results A total of 170 patients were included, with a mean age of 60.9 ± 9.5 years; 78.6% were overweight or obese, and 44.1% had diabetes mellitus. Primary implantations accounted for 77.1% of cases. Ten infections were identified (5.9%), with eight requiring prosthesis removal (4.7%). The median time to infection was 2 months (IQR 1.5–4). A total of 89 patients (54.9%) received prolonged postoperative antibiotics, most frequently amoxicillin-clavulanate (55.4%). The infection rate was 7.9% in patients receiving prolonged antibiotics versus 4.1% in those who did not (p = 0.323). The prosthesis model was the only variable significantly associated with infection (χ2 = 38.7, p < 0.001), with higher infection rates in Tactra and Zephyr implants; however, these subgroups had very small sample sizes. Logistic regression analysis identified no independent predictors of infection. Conclusions Extending postoperative antibiotic therapy did not reduce the rate of prosthesis infection. The overall infection rate (5.9%) was slightly higher than that reported in high-volume reference centers (1–3%). Several factors may account for this difference. First, our population included a high proportion of patients with comorbidities such as diabetes mellitus (44%) and obesity, both well-established risk factors. Second, approximately one fifth of the procedures were revision or reimplantation surgeries, which are known to carry a substantially higher risk of infection. Finally, our definition of infection was intentionally broad, which may have contributed to a higher rate compared with series that report only explantations. Taken together, these factors suggest that the infection rate observed in our cohort reflects the complexity of the treated population and the real-world nature of clinical practice rather than a true deviation from expected outcomes. No patient- or surgery-related variable independently predicted infection, likely reflecting the small number of infection events and the limited statistical power of the analysis. The apparent higher infection rate in patients receiving prolonged postoperative antibiotics likely reflects confounding by indication, as surgeons may have preferentially prescribed longer antibiotic courses for patients perceived as being at higher risk. Disclosure No