Risk Factors of Postoperative Spinal Epidural Hematoma after Biportal Endoscopic Spinal Surgery

Abstract Background Though postoperative spinal epidural hematoma is a rare complication, it can cause severe neurological complication. Studies regarding biportal endoscopic spinal surgery, a type of minimally invasive spinal surgery technique, have been recently reported. The purpose of our study is to report the incidence and risk factors of postoperative hematoma after biportal endoscopic spinal surgery. Methods The subjects of this study were 310 patients that underwent biportal endoscopic spinal surgery from 2015 to 2017. MRI was performed in all patients before surgery, and also after surgery to identify epidural hematoma. Using electronic medical records, perioperative factors such as age, gender, operation name, operation level, water infusion pump usage, thrombin-containing hemostatic, and anti-coagulant medication were statistically analyzed in the aspect of postoperative hematoma. Results The overall occurrence rate of postoperative hematoma was 23.6% (94 cases). A total of 304 levels (76.4%) were without hematoma according to the postoperative MRI among the total 398 levels. Six patients underwent revision surgery of hematoma evacuation. Female, old age (over 70 years), preoperative anticoagulation medication, and usage of intraoperative water infusion pump were significantly correlated to the occurrence of postoperative hematoma. Conclusion Though symptomatic postoperative hematoma was extremely rare at 0.019%, radiological hematoma confirmed by postoperative MRI was higher of 23.6%. The perioperative risk factors of postoperative hematoma after biportal endoscopic spinal surgery include female, old age (over 70 years), preoperative anticoagulation medication, usage of intraoperative water infusion pump, and surgery requiring more bone work (laminectomy or interbody fusion).