Post-Operative Spinal Epidural Hematoma: Are We Discontinuing Aspirin Early Enough?

Study Design: Retrospective cohort study.

Objectives: (1) To compare the risk of Spinal Epidural Hematoma (SEH) associated with specific pre-operative and post-operative anticoagulation (AC) and antiplatelet medications (APM). (2) To define the incidence of SEH and identify risk factors for SEH in our population.

Methods: Thoracolumbar surgeries between October 2009 and March 2020 were collected. Patients who underwent incision and drainage of a symptomatic SEH were identified. AC and APM was recorded 14 days pre-operatively and post-operatively. Demographics and intra-operative factors were recorded. Relative risk with 95% confidence interval was used, with Bonferroni-corrected -values <.05 used for significance.

Results: 9307 surgeries were identified. 177 (1.9%) patients returned to the OR within 30 days, 37 of whom (.39%) returned due to SEH. Seven patients were on either AC or APM pre-op, and sixteen post-op. Five were on aspirin pre-operatively (RR 3.2, 95% CI 1.25-8.22, P = .015). Risk was not increased in patients on multiple agents. No AC or APM demonstrated increased risk of hematoma post-operatively, despite trends toward significance with multiple agents. The use of a drain and complicated hypertension were associated with increased risk of SEH.

Conclusions: Pre-operative aspirin is associated with increased risk of SEH, even when appropriately discontinued. Appropriately dosed post-operative anticoagulation does not increase the risk of SEH, though being on multiple agents trends toward statistical significance and should be better studied. Surgeons should be vigilant and carefully monitor patients on pre-operative antiplatelet medications for spinal epidural hematoma.