Differences in sacral neuromodulation device infection rates based on preoperative antibiotic selection

Abstract

After SNM implantation the most significant complication that can occur is wound infection, which typically requires removal of all components. Such infections have been reported in 5-11 % of patients, but little is known about risk factors. The objective of this analysis is to determine our postoperative wound infection rate after SNM implantation, and examined various potential predictive factors. Our hypothesis is that perioperative antibiotic selection is related to the risk of infections. A retrospective review was performed of all patients who underwent SNM implantation by one of three surgeons from 2007 to 2010. Preoperative antibiotics were administered according to surgeon preference, and included cefazolin alone, vancomycin alone, or vancomycin with gentamicin. Predictors of wound infection were evaluated using multivariate techniques. Variables examined included preoperative antibiotic regimen, surgeon, location (outpatient surgery center vs university hospital), gender, comorbidities (diabetes mellitus, immunosuppression and smoking), history of urinary tract infections, and preoperative skin preparation. A total of 136 patients underwent SNM implantation, and 8 (5.9 %) experienced infections that required device explantation. Cefazolin alone was less effective in preventing infection compared with the other antibiotic regimens (p = 0.03). The odds of having an infection in cefazolin-treated patients was 7.3 times that of other patients treated with another antibiotic regimen. Seven out of the eight infections with explant grew Staphylococcus aureus resistant to cephalosporins. None of the other variables proved to be a statistically significant contributor. Preoperative antibiotic selection was a significant factor in preventing subsequent infection and explantation following SNM placement.