Acute Spinal Subdural Hematoma Subsequent To Posterior Lumbar Fusion

Abstract

Objective: To report a rare case of post-operative cauda equina syndrome subsequent to lumbar decompression and reconstruction, and review the relevant anatomical causes of spinal subdural hematoma. We present a case report of an acute spinal subdural hematoma, following surgical decompression and fusion. The etiology of spinal subdural hematoma after spinal surgery is controversial. We propose that violation of the dural-arachnoid interface is a likely mechanism of this complication. Summary of background data: Spinal subdural hematoma (SSDH) is a very rare postoperative complication of surgical decompression. We report the presentation of acute SSDH presenting with acute cauda equine, following lumbar decompression and reconstruction in a patient lacking risk factors for this rare complication. Methods: A 72 year old man with a history of prior L2-5 laminectomy presented with persistent lower back and left lower extremity radicular pain, due to lumbar spondylosis with foraminal stenosis due to synovial cyst, and lumbar disc herniation. He underwent a revision L2-5 laminectomy with foramintomies, L3-4 synovial cyst resection, and L3-4 posterolateral instrumented fusion. Small incidental duratomy without arachnoid fenestration and without cerebrospinal fluid extravasation, was noted and repaired intraoperatively. On post-operative day four, the patient presented with acute cauda equina syndrome, found to be associated with an acute dorsal lumbar subdural hematoma. Results: After emergent evacuation of the hematoma, patient had immediate resolution of symptoms, and continued to demonstrate dramatic improvement after 1-year follow-up. Conclusions: Despite its low incidence, SSDH should be considered in the setting of acute cauda equina syndrome, following surgical decompression. Prompt evacuation of hematoma is associated with good prognosis. The etiology of SSDH post spinal surgery is controversial. Violation of the dural-arachnoid interface and destruction of local neurothelial cells is the suspected etiology of this very rare complication.