Organized Epidural Hematoma and Peridural Fibrosis After Unilateral Biportal Endoscopic Decompression: A Case Report

Background: Unilateral biportal endoscopic (UBE) surgery is a minimally invasive technique for lumbar degenerative disease. Symptomatic postoperative spinal epidural hematoma requiring revision is uncommon, and an organized epidural hematoma with dense peridural fibrosis found long after UBE surgery is rarely reported. Case Presentation: A 32-year-old man who had undergone left L4–L5 UBE unilateral laminotomy for bilateral decompression (UBE-ULBD) presented with persistent low back pain, left lower-limb radiculopathy, difficulty walking, and restricted back movement. Magnetic resonance imaging (MRI) showed postoperative epidural pathology compressing the thecal sac and left-sided neural structures. Conservative management had failed, and revision surgery was performed approximately 4 years after the index procedure. Microscopic exploration revealed findings consistent with an organized epidural hematoma with dense peridural fibrosis and adhesions. Microscopic evacuation and adhesiolysis achieved adequate intraoperative decompression. The diagnosis rested on intraoperative findings because histopathology was unavailable. The timing of lesion formation could not be established because serial postoperative imaging was unavailable, and postoperative outcome data were not available. Conclusion: Organized epidural hematoma with peridural fibrosis should be considered in the differential diagnosis of persistent radiculopathy after lumbar endoscopic surgery. MRI identifies compressive epidural pathology, but characterization of chronic lesions may require operative correlation and histopathology.