Incidence and risk factors of spinal epidural hemorrhage after spine surgery: a cross-sectional retrospective analysis of a national database.

Background: With increasing number of patients undergoing spine surgery, the spinal epidural hemorrhage (SEH) has become a growing concern. However, current studies on SEH rely on case reports or observations from a single center. Our study attempted to demonstrate the incidence rate and risk factors of SEH using a national dataset.

Methods: A total of 17,549 spine surgery cases from the Health Insurance Review and Assessment Service National Inpatient Sample of 2014 were analyzed. After evaluating the incidence of SEH based on severe cases requiring reoperation, a univariate comparison was performed. Variables found to be significant were included in a multivariable analysis model to determine the risk factors.

Results: The incidence of SEH was found to be 1.15% in Korean population, and there were no severe SEH cases. Our analysis confirmed the previous findings that lumbar surgery, intraoperative blood loss, prolonged surgical time, high blood pressure, use of nonsteroidal anti-inflammatory drugs, and concurrent bleeding factors are the risk factors of SEH. Anterior approach showed a protective effect. The use of anticoagulant demonstrated no statistical significance.

Conclusion: Although severe SEH cases were not detected, the incidence of SEH was similar to that reported in literature. Given that SEH is a rare complication of spine surgery and constitutes an important research area that needs to be studied further, our study makes a meaningful contribution based on a rigorous national level sample for the first time and provides the academic circle and health professionals with a reliable evidence of improved clinical outcomes in such cases.