Pre-Operative Bariatric Surgery Imparts An Increased Risk of Infection, Re-Admission and Operative Intervention Following Elective Instrumented Lumbar Fusion

Study Design: Retrospective cohort study. Objectives: To evaluate the impact of bariatric surgery on patient outcomes following elective instrumented lumbar fusion. Methods: A retrospective review of a prospectively collected database was performed. Patients who underwent a bariatric procedure prior to an elective instrumented lumbar fusion were evaluated. Lumbar procedures were performed at a large academic medical center from 1/1/2012 to 1/1/2018. The primary outcome was surgical site infection (SSI) requiring surgical debridement. Secondary outcomes were prolonged wound drainage requiring treatment, implant failure requiring revision, revision secondary to adjacent segment disease (ASD), and chronic pain states. A randomly selected, surgeon and comorbidity-matched group of 59 patients that underwent an elective lumbar fusion during that period was used as a control. Statistical analysis was performed using Student's two-way t-tests for continuous data, with significance defined as P < .05. Results: Twenty-five patients were identified who underwent bariatric surgery prior to elective lumbar fusion. Mean follow-up was 2.4 +/- 1.9 years in the bariatric group vs. 1.5 +/- 1.3 years in the control group. Patients with a history of bariatric surgery had an increased incidence of SSI that required operative debridement, revision surgery due to ASD, and a higher incidence of chronic pain. Prolonged wound drainage and implant failure were equivalent between groups. Conclusion: In the present study, bariatric surgery prior to elective instrumented lumbar fusion was associated increased risk of surgical site infection, adjacent segment disease and chronic pain when compared to non-bariatric patients.