Lumbar ligamentum flavum hematoma treated with endoscopy

Hematoma of the ligamentum flavum is a rare cause of neural compression, for which treatment has consisted of excising the hematoma via open surgical approaches, including total laminectomy or bilateral partial laminectomy. This article presents the first report of a microscope-assisted endoscopic decompression to resect a hematoma of the ligamentum flavum.A 52-year-old man presented with back and leg pain, as well as difficulty initiating micturation. Magnetic resonance imaging demonstrated an epidural mass at L5/S1 that was continuous with the facet joint. Visualization was obtained via an endoscope, and a reddish tan-brown solid mass was found beneath the ligamentum flavum. Thorough decompression of the cauda equine and nerve roots was undertaken. The patient's radicular leg pain and bladder function improved soon after the decompression. Histological examination of the ligamentum flavum revealed a consolidated hematoma with granulomatous change.A review of the English literature revealed 29 cases of hematoma in the lumbar ligamentum flavum. Surgical decompression in these patients was accomplished with a standard open approach through hemilaminectomy (n=11), total laminectomy (n=10), or laminectomy followed by posterior fixation (n=3). The literature review did not identify any case of hematoma of the lumbar ligamentum flavum that was treated endoscopically. We expect our case may expand the indications for the endoscope in spine surgery.