Prophylactic Epidural Vancomycin Powder and the Risk of Surgical Site Infection Following Cranioplasty Procedures, a Retrospective Cohort Study

Introduction: One of the major complications after cranioplasty is post-operative infection, with the risk estimated to be between 3-25%. The utility of intrawound vancomycin (IWV) as a prophylactic agent against surgical site infection (SSI) has been shown to be beneficial in orthopedics and spinal neurosurgery. Cranial applications of vancomycin powder for SSI prophylaxis have been reported with varying success, but overall promising results. Herein, we analyze the effects of intraoperative vancomycin on postoperative wound infection in patients undergoing cranioplasty.

Methods: A retrospective cohort study was performed in patients who underwent cranioplasty after decompressive craniectomy for trauma, stroke, or infection between 2013-2022 at a level 1 trauma center in Montreal, Canada. Patients who received IWV during cranioplasty were compared to a pre-intervention group who did not receive IWV. The primary outcome of interest was occurrence of infection within 2 months following cranioplasty. A logistic regression model was used to compare the odds of infection occurring between groups.

Results: Total of 138 cranioplasty cases were included in the final analysis. IWV was applied in 67 cases, and 71 cases were in the non-IWV group. The mean age in both groups was 43.1 years. Overall, 90.6% of patients underwent craniectomy for traumatic brain injury (TBI), 5.8% due to prior craniotomy site infection and 3.6% due to stroke. Mean time to cranioplasty was similar in both groups. When adjusting for age, sex, and time to cranioplasty, patients who received vancomycin during cranioplasty had lower odds of developing infection within 2 months postoperatively when compared with patients who did not receive vancomycin (OR 0.07; 95% CI [0.004, 0.49], p=0.023).

Conclusion : Vancomycin powder has a role in reducing the rate of post cranioplasty surgical site infection. Large prospective randomized clinical trials will be essential in drawing more powerful conclusions regarding this prophylactic application.