Association of Cerebrovascular Injury and Secondary Vascular Insult with Poor Outcomes Following Gunshot Wound to the Head in a Large Civilian Population

Introduction: Cerebrovascular injury (CVI) from civilian gunshot wound to the head (GSWH) is likely a significant contributor to poor outcomes, but little supporting evidence exists. This study analyzed a large civilian population for incidence of CVI, imaging predictors, and outcomes following GSWH.

Methods: In this single institution retrospective cohort study from 2014–2022 at a level 1 trauma center, patient records with GSWH and adequate vascular imaging were analyzed. Imaging was reviewed for presence of CVI, bullet trajectory, and injury characteristics. Outcome measures included mortality, “good outcome” of Glasgow outcome scale (GOS) 4-5 at follow-up, and secondary cerebrovascular insult (new stroke or re-hemorrhage).

Results: Overall, 172 of 512(33.5%) patients were included and 87(51%) had CVI, including 32(18.6%) arterial intimal injuries/dissections, 12(7.0%) pseudoaneurysms, 10(5.8%) large vessel occlusions, and 27(15.7%) venous sinus thromboses. Patients with CVI had lower admission Glasgow coma scale (7.8 vs 9.6, p=0.0108) and more lobes traversed by the bullet (2.1 vs 1.3, p< 0.0001). The latter predicted higher odds of CVI (aOR=3.18, p< 0.001). On logistic regression, CVI was associated with increased mortality (aOR=3.61, p=0.015) and decreased “good outcome” at follow-up (OR=0.10, p< 0.001). In a propensity-matched cohort balanced for demographics, admission GCS and trajectory variables, CVI remained significantly associated with increased mortality and poor functional outcome. A third of patients with CVI had a secondary vascular insult including re-hemorrhage (5[5.7%]) or delayed stroke (23[26.4%]) attributable to the underlying CVI. These patients had significantly decreased “good outcome” at follow-up (aOR=0.012, p=0.001) compared to patients with CVI but without secondary insult.

Conclusion : This study presents the largest civilian series to date describing CVI in patients with GSWH. It is the first to demonstrate CVI is associated with poor functional outcome at follow-up and that secondary vascular insult is associated with worse outcomes, suggesting benefit from early screening and aggressive management of CVI.