Evidence & Methods
Over the last few years, the utilization of vancomycin powder in surgical wounds has gained popularity as an added means of prophylaxis against post-operative infection. The authors sought to assess outcomes and costs associated with this technique in a series of 303 patients.
The authors report that of the 96 patients in the cohort treated with vancomycin powder, there were no infections that required return to the operating room. Over $1 million in expenditures were generated by seven patients in the control arm who required surgical intervention for the treatment of post-operative infection.
The present study adds additional information to the growing literature regarding use of intrawound vancomycin powder. There are limitations to the widespread translation of this study’s findings, however, and these should be appreciated. The authors highlight some of these in the limitation section of their discussion. Also important is the fact that the two groups differed significantly on a number of vital parameters, including patient age, the presence of diabetes and the type of surgery performed. This clearly confounds the capacity to attribute the study’s results, in their entirety, to the use of vancomycin powder. Moreover, the intent of an analysis of this kind is, ideally, to draw a sample population is representative of the larger demographic. In this instance, to be considered as such, the reader must accept that surgical site infections requiring operative intervention would never occur in the setting of intrawound vancomycin application. Other available literature contests this fact and this represents another, quite substantive, limitation of the current work. While this effort, combined with other studies, lays the groundwork for future analyses on this issue, higher quality, scientifically rigorous, investigations are certainly necessary.
—The Editors
About 300,000 spinal surgeries are performed each year in the United States [1], with single cases costing, on average, $92,884 according to the DRG Summary for Medicare Inpatient Prospective Payment Hospitals, FY201 [2].
A major complication of spine surgery is postoperative surgical site infection (SSI) that can be devastating. Although the reported frequency and severity of these infections vary widely, with reported rates of 0.7% to 15% [3], [4], [5], [6], [7], [8], [9], [10], [11], [12], [13], the use of antibiotic prophylaxis is well established. The incidence of SSI has been noted to vary, depending on the procedure, with rates in short lumbar instrumentation as low as 2% to 4% [14], [15], [16] and as high as 8% to 15% in special situations, such as in trauma patients or those with cerebral palsy [13], [14]. Not only does SSI cause additional morbidity and mortality, but health care resources must be expended to manage it [15], [16].
Most SSIs after spine surgery are caused by Gram-positive organisms [17]. As a result, the use of intrawound vancomycin to prevent this complication is becoming more common. Recent publications have demonstrated a reduction in SSI with the use of intrawound vancomycin in posterior spine surgery, both in trauma patients [18], [19] and in patients undergoing elective procedures [19], [20]. The use of intrawound vancomycin in this setting achieves a high but well-localized tissue concentration of antibiotic and, given the size of the vancomycin molecule, there is very minimal ingress into the systemic circulation.
Although increased costs are known to be associated with SSI after spine surgery, and intrawound vancomycin is known to reduce the frequency of SSI, the potential budgetary impact of this reduction in SSI has yet to be elucidated. This study was designed to analyze the cost savings associated with the use of prophylactic intrawound vancomycin in posterior spine surgery.