Revisiting Anticoagulation in Spine Surgery: Balancing Venous Thromboembolic Events and Epidural Hematoma.

Study design: Retrospective Cohort Study.

Objective: Venous thromboembolic events (VTE) and post-operative epidural hematoma (EDH) are significant complications after spine surgery. Guidelines for chemoprophylaxis are controversial and variability amongst surgeons remains. The objective of this study was to establish the incidence of clinical VTE and EDH at our institution and evaluate the association of chemoprophylaxis with clinical VTE and EDH.

Methods: We conducted a retrospective cohort study of patients undergoing spine surgery at a high-volume tertiary care center in Seattle, WA between January 2016 and December 2019. The Premier Health Care Database and Agency for Healthcare Research and Quality (AHRQ) patient indicators PSI-9 (Perioperative hemorrhage and hematoma) and PSI-12(Perioperative PE or DVT) were used to identify patients experiencing VTE and/or post-operative EDH. The primary outcome was the incidence of clinical VTE and EDH in post-operative spine patients. Secondary outcomes included the association of chemoprophylaxis with clinical VTE and EDH.

Results: From 2016 to 2019, 4587 patients underwent spine surgery, totaling 4764 hospital stays. The incidence of clinical VTE was .21% (10/4764) and the incidence of EDH was .10% (5/4764). Most hemorrhages occurred prior to the initiation of chemoprophylaxis. One patient with EDH received chemoprophylaxis prior to hemorrhage.

Conclusions: The rate of post-operative clinical VTE and EDH in spine surgery is low. Despite early initiation of chemoprophylaxis after major spine surgery we did not appreciate a high rate of EDH. We attribute our low rate of clinical VTE to multimodal prophylaxis with SCDs, early mobilization and chemoprophylaxis on post-operative day 1.