Symptomatic Epidural Hematoma After Elective Cervical Spine Surgery: Incidence, Timing, Risk Factors, and Associated Complications.

BACKGROUND As the rate of elective cervical spine surgery increases, studies of complications may improve quality of care. Symptomatic postoperative cervical epidural hematomas (PCEH) are rare but result in significant morbidity. Because of their low incidence, the risk factors and complications associated with symptomatic PCEH remain unclear. OBJECTIVE To clarify the prevalence, timing, variables, and complications associated with PCEH following elective cervical spine surgery. METHODS Using the American College of Surgeons National Surgical Quality Improvement Program database, cervical spine surgeries performed between 2012 and 2016 were identified using Current Procedural Terminology codes. Symptomatic PCEH was defined as readmission or reoperation events specifically associated with International Classification of Diseases code diagnoses of postoperative hematoma within 30 d of index surgery. Multivariate models were created to assess the independent association of symptomatic PCEH with other postoperative complications. RESULTS There were 53233 patients included for analysis. The overall incidence of symptomatic PCEH was 0.4% (n = 198). Reoperation occurred in 158 cases (78.8%), of which 2 required a second reoperation (1.3%). The majority (91.8%) of hematomas occurred within 15 d of surgery. Multivariate analysis identified male gender, American Society of Anesthesiologists classes 3 to 5, bleeding disorder, increasing number of operative levels, revision surgery, dural repair, and perioperative transfusion as independent factors associated with PCEH. Upon controlling for those confounders, PCEH was independently associated with cardiac arrest, stroke, deep vein thrombosis, surgical site infection, and pneumonia. CONCLUSION Postoperative epidural hematomas requiring readmission or reoperation following elective cervical spine surgery occurred at an incidence of 0.4%. Symptomatic PCEHs are associated with increased rates of numerous major morbidities.