234. Does nasal screening for methicillin resistant Staphylococcus aureus (MRSA) prevent deep surgical site infections for elective cervical spinal fusion?

Abstract

<h3>BACKGROUND CONTEXT</h3> Preoperative MRSA screening and decolonization has demonstrated success for some orthopaedic subspecialties in prevention of surgical site infections (SSIs). Spine surgery, however, has seen varied results, potentially secondary to the anatomic and surgical heterogeneity of the patients included in prior studies. Given that prior research has demonstrated greater propensity for gram positive SSIs in the cervical spine, we sought to investigate if MRSA screening would be more impactful in the cervical spine. <h3>PURPOSE</h3> The purpose of this study was to determine the relationship between nasal MRSA testing and SSI rates specifically in the setting of primary posterior cervical instrumented spine surgery. <h3>STUDY DESIGN/SETTING</h3> Retrospective cohort study. <h3>PATIENT SAMPLE</h3> Adult patients undergoing primary instrumented posterior cervical procedures from January 2015-December 2019 at two tertiary academic referral centers in an urban setting <h3>OUTCOME MEASURES</h3> Physiologic measures: subfascial presumed infected collection or abscess within 90 days of the index operation. <h3>METHODS</h3> Adult patients undergoing primary instrumented posterior cervical procedures from January 2015-December 2019 were reviewed for MRSA testing < 90-days before surgery, preoperative mupirocin, perioperative antibiotics and SSI defined as operative incision and drainage (I&D) < 90-days after surgery. Trauma, tumor and infection cases were excluded. Logistic regression modeling was used with SSI the primary outcome and MRSA screening the primary predictor with clinical and demographic factors as covariates. <h3>RESULTS</h3> This study included 668 patients, of whom MRSA testing was performed in 212 patients (31.7%) and 6 (2.8%) were colonized with MRSA. Twelve patients (1.8%) underwent an I&D. On adjusted analysis, preoperative MRSA testing was not associated with postoperative I&D risk. Perioperative vancomycin similarly had no association with postoperative I&D risk. Notably, six patients (50%) grew MSSA from intraoperative cultures, with no cases of MRSA. <h3>CONCLUSIONS</h3> There was no association between preoperative nasal MRSA screening and SSIs in primary posterior cervical instrumented procedures, nor was there any association between vancomycin or infection rate. Furthermore, there was a preponderance of gram-positive infections but none caused by MRSA. Given these findings, the considerable cost and effort associated with MRSA testing in the setting of primary posterior cervical instrumentation may not be justified. Further research should investigate if higher-risk scenarios demonstrate greater utility of preoperative testing. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.