Antithrombotic Delay and Stroke Risk in Traumatic Vertebral Artery Injury Patients Requiring Spine Surgery

Introduction: Traumatic vertebral artery injury (TVAI) patients are managed with early antithrombotic treatment to mitigate elevated ischemic stroke risk. In TVAI patients requiring surgical intervention for concomitant spine injuries, there is a need to balance benefits of stroke prevention with risks of perioperative hemorrhage. We aim to characterize the differences in antithrombotic initiation timing and incidence of ischemic stroke in surgical and non-surgical TVAI cohorts.

Methods: A registry of TVAI patients over 7 years at a level 1 trauma center was queried. Patients triaged per the Denver criteria with confirmed injury on imaging and initiated on antithrombotics for stroke prevention were included. Differences in Biffl grades, antithrombotic initiation timing, and rate of embolic or posterior circulation stroke within 14 days of injury, and attributable risk (AR) for a stroke event were compared between surgical and non-surgical cohorts.

Results: Of 121 patients, 44 underwent neurosurgery. There was no significant difference in the severity of vertebral injury per the Biffl scale between surgical and non-surgical cohorts (median 3 [IQR 1-4] v. 2 [IQR 1-4], p=0.28). Mean time from injury to antithrombotic initiation was significantly greater in the surgical cohort (mean 3.18 days, SD 2.16 days) than non-surgical cohort (mean 1.06 days, SD 1.15 days, p< 0.001). Stroke occurrence in the surgical cohort was significantly greater than the non-surgical cohort (20.5% v. 5.19%, p=0.02). The AR for stroke in patients requiring surgery is 15.3%.

Conclusion : TVAI patients requiring neurosurgical interventions are at a 15% higher risk for ischemic stroke. Despite similar distributions in vertebral injury severity, there is an average 2-day delay in antithrombotic initiation due to surgery. Future studies are needed to balance benefits of earlier antithrombotic initiation with risks of perioperative bleeding to optimize antithrombotic treatment in TVAI patients requiring surgery.