Incidence and risk factors of postoperative symptomatic spinal epidural hematoma in cervical spine surgery: a single center, retrospective study of 18,220 patients.

Abstract

The goal of this research is to explore the incidence and risk factors of symptomatic spinal epidural hematoma (SSEH) following cervical spine surgery. Patients with SSEH from January 2009 to February 2019 were identified as hematoma group. Two control subjects without SSEH were randomly selected for each patient in SSEH group as control group. We collected gender, age, body mass index (BMI), ossification of the posterior ligament (OPLL), comorbidities, anti-platelet or anti-coagulate treatment, coagulation function, segments, instrumental fixation, surgical approach, surgical procedure, duration of surgery and estimated blood loss, which might affect the occurrence of symptomatic epidural hematoma. T-test and Chi-square test were used to univariable test. Multifactor logistic regression analysis was used to investigate the correlation with symptomatic epidural hematoma, furthermore its causes were explored. Among 18,220 patients, 43 subjects developed SSEH, the incidence was 0.24%. The median time from the end of index surgery to SSEH was 150 min (25 and 75 percentile: 85 min to 290 min). The neurologic function before evacuation by modified Frankel scale is grade B in 5 patients, C in 32 patients, grade D in 6 patients. All patients' symptoms relieved partially or completely after evacuation. All patients with neurologic deficit worse than grade C pre-evacuation had at least one-grade improvement except for one patient. Multifactor logistic regression revealed OPLL involved segments are significantly correlated to the incidence of postoperative symptomatic epidural hematoma (P < 0.05), with a cut-off value of 1.5 levels. OPLL involved segments are significantly correlated to the incidence of postoperative symptomatic epidural hematoma.