Postoperative spinal epidural hematoma: a systematic review.

STUDY DESIGN: Surgeon survey. OBJECTIVE: To characterize the incidence of epidural hematoma in postoperative spinal patients; to assess the effect of chemical thromboprophylaxis on the risk of epidural hematoma. SUMMARY OF BACKGROUND DATA: The precise indications and/or timing of anticoagulation for thromboembolic prophylaxis following spinal surgery are not clear. Patients who endure periods of extended recumbency and limited mobility after major operative spinal interventions may be at increased risk of thromboembolic disease. Among other factors, spine surgeons must weigh the risk of a symptomatic postoperative epidural hematoma against the benefit of DVT/PE prevention when deciding to initiate chemoprophylaxis. However, the incidence of postoperative epidural hematoma is not well-known, leading to uncertainty regarding the real versus perceived risk of this complication. METHODS: The MEDLINE database was queried using the search terms epidural hematoma and spinal or spine surgery. Abstracts of all identified articles were reviewed. Studies were deemed eligible if they specifically documented the incidence of clinically significant epidural hematoma in a series of patients who underwent spinal surgery. Detailed information from eligible articles was extracted. Data were compiled and analyzed to examine incidences of clinically relevant postoperative epidural hematoma (i.e., resulted in new, associated neurologic deficit). RESULTS: Of 493 abstracts that were identified in the search, a total of sixteen articles were eligible for full review. From this review, the range of reported incidences of epidural hematoma in the literature ranges from 0% to 0.7% in studies where patients received chemical anticoagulation and 0% and 1% in all of the included studies. In no study was the incidence of clinically relevant epidural hematoma greater than 1%. CONCLUSION: The catastrophic morbidity of a symptomatic postoperative epidural hematoma remains a substantial disincentive to start chemoprophylaxis after spinal surgery. The rarity of this complication makes study of its risk factors difficult. Although many surgeons perceive the risk to be higher, the reported incidences of clinically relevant postoperative epidural hematoma are lower, ranging from 0% to 1%. Despite this finding, there is insufficient published data available to precisely define the safety of postoperative chemoprophylaxis. Though not pertaining to prophylaxis, the available evidence does suggest that use of therapeutic doses of heparin in postoperative spinal patients who sustain a PE may have a higher incidence of bleeding complications.