Postoperative Spinal Epidural Hematomas: Longitudinal Review of 12,000 Spinal Operations
Randall W. Porter, MD
Paul W. Detwiler, MS, MD
Michael T. Lawton, MD†
Volker K.H. Sonntag, MD
Curtis A. Dickman, MD
Division of Neurological Surgery, Barrow Neurological Institute, St. Joseph’s Hospital and Medical Center, Phoenix, Arizona
†Current Address: University of California, San Francisco, California
A retrospective review of 12,000 patients who underwent spinal surgery from 1979 to 1996 revealed 17 patients who developed postoperative spinal epidural hematomas that required evacuation. We attempted to determine if surgical timing, rate of symptom progression, or preoperative Frankel grade influenced outcome. New deficits were present immediately after surgery in seven patients and presented in a delayed fashion in 10 patients. The mean interval from symptom onset to surgery was 17.7 hours (range, 1.7 to 132 hours). Postoperative motor and sensory deficits developed from C4 to S2 and patients deteriorated a mean 1.2 grades. Twelve patients were evaluated with CT myelography or MR imaging, one with plain radiographs, and four on clinical suspicion alone. Postoperative symptoms were immediate in seven and delayed in 10 patients. Coagulopathy and vascular lesions were the most common causes for postoperative spinal epidural hematomas. At late follow-up (mean length, 31.6 months), 10 patients had returned to their baseline, 5 had improved, and 2 were worse. Patients who had their hematomas evacuated in less and more than 6 hours improved a mean of 2.1 and 0.6 Frankel grades, respectively. Four patients deteriorated to Frankel A grades but still improved a mean of 1.75 grades after evacuation. Rapid evacuation of postoperative spinal epidural hematomas may maximize neurological outcomes, and even patients with complete sensorimotor deficits may improve after evacuation.
Key Words: complications, epidural hematoma, spinal cord injury
Spinal epidural hematomas are a rare cause of neurologic deficits and spinal cord compression. First described by Jackson in 1869, spinal epidural hematomas result from anticoagulation,[13,17,18,24] hemophilia, pregnancy, trauma,[17,22,23] garlic ingestion, a complication of anterior cervical discectomy, aspirin, hypertension, epidural anesthesia,[5,17] Paget's disease, hemangioma,[15,24] arteriovenous malformation (AVM),[6,17] and epidural varicose veins. They also may occur spontaneously[2,10,17,22,23] with no obvious etiology.
Considering the large number of spinal operations performed each year, spinal epidural hematomas are surprisingly rare after spinal surgery.[3,8,16,33] Nonetheless, spinal surgeons should be aware of this clinical entity and its predisposing factors. Previously, we reported 30 patients with spinal epidural hematomas from all causes, 12 of which occurred postoperatively. This article adds five more cases and more closely examines this subpopulation of patients.
Materials and Methods
Between 1979 and 1996, 17 (14 males and 3 females) patients undergoing spinal surgery at our institution developed spinal epidural hematomas that needed evacuation. Their mean age was 51 years (range, 6 months to 78 years). Patients’ medical records, radiographs, operative reports, and pathology reports were reviewed retrospectively. Postoperative spinal epidural hematomas were confirmed by magnetic resonance (MR) imaging or computed tomography (CT)-myelography, by the surgeon intraoperatively, by the pathologist histologically, or by all three.
Figure 1. A 73-year-old male had undergone a prior L5 laminectomy. He became symptomatic with a right foot drop caused by a herniated disc at L4-L5. After undergoing a microdiscectomy, he complained of L4-L5 radiculopathy. Computed tomography-myelography showed a spinal epidural hematoma from L4-S1, which was evacuated without sequelae
The subjects underwent a variety of surgical procedures throughout the spinal axis. Anterior cervical discectomy with and without fusion accounted for the largest group (n
=6), two of whom underwent plating procedures with Synthes (Synthes® Spine, Paoli, PA) plates. One patient underwent a multilevel cervical corpectomy. Three patients underwent laminectomies for spinal epidural hematomas. Three patients had spinal AVMs—one cervical (the patient presented with a spinal epidural hematoma), one cervicothoracic, and one thoracolumbar. One patient underwent a thoracic laminectomy for spinal cord compression due to nonHodgkin's lymphoma. Two patients underwent posterior thoracolumbar decompression with instrumentation. Three patients underwent lumbar laminectomies for spinal stenosis (Table 1). Patients 8
had drains placed at surgery for excessive oozing. Both had coagulopathies. Patient 8
was a 6 month old who had 425 ml of output in 24 hours. Patient 15
was an adult who had 100 ml of output in the 12 hours after the first surgery.
The Frankel grading system was used to grade each patient’s neurologic status: A=complete motor and sensory loss; B=complete motor, incomplete sensory loss; C=incomplete motor loss, nonfunctional; D=incomplete motor loss, functional; and E=no neurological deficits. The patients’ neurologic status was defined at four points in time: before the initial surgical procedure, after the initial procedure (at the time of deterioration), after evacuation of the postoperative spinal epidural hematoma, and at late follow-up. The patient’s urologic function was also ascertained before surgery, at the time the postoperative spinal epidural hematoma occurred (when available), and at follow-up.
During the 17-year study period, approximately 12,000 spine operations were performed at our institution. Seventeen patients developed postoperative spinal epidural hematomas, an incidence of 0.14%. Before the initial surgery, four patients were Frankel grade E, seven were grade D, three were grade C, and three were grade B (Table 1). Bladder function was normal in nine patients and abnormal in six. Bladder function could not be determined in the two patients who were younger than 1 year.