Data presented by Nickalus R Khan, winner of the DePuy Synthes Spinal Cord Injury Resident Award, indicate that although vancomycin may protect against infection, the most suitable patient population is not clear. The data were presented at 2015 American Association of Neurological Surgeons Annual Scientific Meeting (AANS; 2–5 May, Washington, DC, USA).
Surgical site infection is a serious and costly complication of spinal surgery. There have been several conflicting reports on the use of intrawound vancomycin powder in decreasing its incidence in spine surgery.
In this meta-analysis, a comprehensive search of multiple electronic databases and bibliographies was conducted to identify clinical studies that evaluated the rates of surgical site infection with and without the use of intrawound vancomycin powder in spine surgery. Independent reviewers extracted data and graded the quality of each paper that met inclusion criteria. A random effects meta-analysis was then performed.
The research identified eight retrospective cohort studies (level III evidence) and one randomised controlled trial (level II). There were 2,424 cases and 95 infections in the control group (3.9%) and 2,368 cases and 28 infections (1.1%) in the treatment group, yielding a pooled absolute risk reduction and relative risk reduction of 2.8% and 72%, respectively. The meta-analysis revealed the use of vancomycin powder to be protective in preventing infection (relative risk=0.30, 95% confidence interval 0.14-0.67, p<0.011). The number needed to treat to prevent one infection was 36. A subgroup analysis found that patients who had implants had a reduced risk of surgical site infection with vancomycin powder (p=0.023), compared to those who had non-instrumented spinal operations (p=0.226).
This meta-analysis suggests that the use of vancomycin powder may be protective against surgical site infection in open spinal surgery; however, the exact population in which it should be used is not clear. This benefit may be most appreciated in higher-risk populations or in facilities with a high baseline rate of infection.