Defining a Hba1c Value That Predicts Increased Risk Of Penile Implant Infection

To explore the association between HbA1C level and penile implant infection rates and to define a cut-off value that predicted implant infection.

A multi center prospective study included all patients undergoing penile implant surgery between 2009-15. Preoperative, perioperative and postoperative management were identical for the entire cohort. Univariate analysis was performed to define predictors of implant infection. HbA1c levels were analyzed as a continuous variable and sequential analysis was conducted utilizing 0.5% increments to define a cut-off level predicting implant infection. Multivariable analysis was performed with the following factors entered the model: Diabetes, HbA1C level, patient age, implant type, vascular risk factor number, presence of Peyronie's disease (PD), BMI and surgeon volume. A ROC curve was generated to define the optimal HbA1C cut-off for infection prediction.

902 implant procedures were performed over this period of time. The mean age was 56.6 years. The mean HbA1c level was 8.0, with 81% of men having a HbA1c >6%. 685 (76%) implants were malleable, and 217 (24%) were inflatable devices. 302 (33.5%) patients had also a diagnosis of PD. Overall infection rate was 8.9% (80/902 subjects). Patients who had implant infection had significantly higher mean HbA1c levels, 9.5% vs 7.8% (p<0.001). Grouping the cases by HbA1c level we found infection rates were: 1.3% with HbA1c <6.5%, 1.5% for 6.5-7.5%, 6.5% for 7.6-8.5%, 14.7% for 8.6-9.5%, 22.4% for >9.5%. (p<0.001). Patient age, implant type, and vascular risk factor number were not predictive. Predictors defined on MVA were: PD, increased BMI, high HbA1C while a high-volume surgeon had a protective effect and was associated with a reduced infection risk. Using ROC analysis, we determined that a HbA1c cut-off value of 8.5% predicted infection with a sensitivity of 80% and a specificity of 65%.

Uncontrolled DM is associated with increased risk of infection after penile implant surgery. The risk is directly related to HbA1C level. A threshold value of 8.5% is suggested for clinical use to identify patients at increased infection risk. This article is protected by copyright. All rights reserved.

BJU international. 2017 Nov 10 [Epub ahead of print]

Mohamad Habous, Raanan Tal, Tarek Soliman, Alaa Tealab, Mohammed Nassar, Zenhom Mekawi, Saad Mahmoud, Osama Abdelwahab, Mohamed Elkhouly, Hatem Kamr, Abdallah Remeah, Saleh Binsaleh, David Ralph, John Mulhall

Urology & Andrology Department, Elaj Medical Centers, Saudi Arabia., Sexual& Reproductive Medicine Program, Urology Service, Memorial Sloan Kettering Cancer Center, NY, USA., Benha University, Urology, Egypt., Zagazig University, Urology, Egypt., King Saud University, Riyadh, Saudi Arabia., St Peters Andrology Centre &The Institute of Urology UCLH, London.