Operative Duration as an Independent Risk Factor for Postoperative Complications in Single-Level Lumbar Fusion

STUDY DESIGN: Multicenter retrospective cohort study. OBJECTIVE: To estimate the impact of increasing surgical duration on outcomes after single-level lumbar fusion. SUMMARY OF BACKGROUND DATA: Lumbar fusion is a widely used practice for the treatment of disability and chronic low back pain. Longer operative duration is shown to correlate with increased morbidity and mortality in various surgical disciplines, but no large-scale study has been performed to validate this relationship in lumbar spine surgery. METHODS: The American College of Surgeons National Surgical Quality Improvement Program was retrospectively reviewed to identify all patients who underwent lumbar fusion procedures during 2006 to 2011. Thirty-day morbidity and mortality rates were reported on the basis of operative time, whereas multivariate logistic regression model was used to examine operative duration as an independent risk factor for outcomes. RESULTS: A total of 4588 patients were included in the analysis. The mean operative duration for all patients was 197 ± 105 minutes. Our multivariate risk-adjusted regression models demonstrated that increasing operative time was associated with step-wise increase in risk for overall complications (odds ratio OR, 2.09-5.73), medical complications (OR, 2.18-6.21), surgical complications (OR, 1.65-2.90), superficial surgical site infection (OR, 2.65-3.97), and postoperative transfusions (OR, 3.25-12.19). Operative duration of 5 hours or more was also associated with increased risk of reoperation (OR, 2.17), organ/space surgical site infection (OR, 9.72), sepsis/septic shock (OR, 4.41), wound dehiscence (OR, 10.98), and deep vein thrombosis (OR, 17.22). CONCLUSION: Our data suggest that increasing operative duration is associated with a wide array of complications. Operative duration is, therefore, an important quality metric in the performance of lumbar fusion. Strategies to reduce operative time and further research to identify risk factors that are associated with longer surgical duration are needed for improved patient outcomes. LEVEL OF EVIDENCE: 3.