Clinical Course of Postoperative Spinal Epidural Hematoma After Microendoscopic Laminectomy for Lumbar Spinal Stenosis

Background Postoperative spinal epidural hematoma (POSEH) is a known complication of spine surgery that occasionally requires reoperation because of severe pain or neurological deficits. However, few studies have examined the clinical course of POSEH after microendoscopic laminectomy (MEL) for lumbar spinal stenosis (LSS). This study investigated the incidence, clinical presentation, and neurological outcomes of POSEH requiring reoperation after MEL for LSS. Methods We retrospectively reviewed patients who underwent MEL for LSS at a single institution between January 2016 and December 2022. Patients with previous lumbar spine surgery were excluded. The diagnosis of POSEH and the indication for reoperation were based on clinical symptoms, with or without MRI findings, in which the hematoma was judged to be the primary cause of symptoms. Clinical characteristics and postoperative courses of patients with POSEH were analyzed. Results In total, 2289 MEL procedures were analyzed. Twenty-three patients (1.00%) developed POSEH requiring evacuation. More than half of the patients (56.5%) developed leg pain within four hours after surgery, and 78.3% developed symptoms by postoperative day one. Only one patient (4.3%) showed delayed onset (postoperative day four). Paresis occurred in five patients (0.22%), all within seven hours after surgery, and all experienced leg pain within four hours. Hematoma evacuation was performed on the day of surgery in all patients with paresis. Four patients recovered completely after reoperation, whereas one patient had mild residual weakness. The rate of permanent neurological deficit was 0.04%. Conclusions POSEH requiring reoperation after MEL for LSS occurred in 1.00% of cases. Paresis developed in 0.22% of patients, and permanent neurological deficit occurred in only 0.04%. Most symptomatic hematomas developed during the early postoperative period, and all patients who developed paresis experienced leg pain within four hours after surgery. Careful monitoring during the early postoperative hours may facilitate early detection and timely management of POSEH.