Prognostic factors associated with risk of stroke following blunt cerebrovascular injury: A systematic review and meta-analysis

Background & objectives: Blunt cerebrovascular injury (BCVI) includes carotid and/or vertebral artery injury following trauma, and conveys an increased stroke risk. We conducted a systematic review and meta-analysis to provide a comprehensive summary of prognostic factors associated with risk of stroke following BCVI. Methods: We searched the EMBASE and MEDLINE databases from January 1946 to June 2023. We identified studies reporting associations between patient or injury factors and risk of stroke following BCVI. We performed meta-analyses of odds ratios (ORs) using the random effects method and assessed individual study risk of bias using the QUIPS tool. We separately pooled adjusted and unadjusted analyses, highlighting the estimate with the higher certainty. Results: We included 26 cohort studies, involving 20,458 patients with blunt trauma. The overall incidence of stroke following BCVI was 7.7 %. Studies were predominantly retrospective cohorts from North America and included both carotid and vertebral artery injuries. Diagnosis of BCVI was most commonly confirmed with CT angiography. We demonstrated with moderate to high certainty that factors associated with increased risk of stroke included carotid artery injury (as compared to vertebral artery injury, unadjusted odds ratio [uOR] 1.94, 95 % CI 1.62 to 2.32), Grade III Injury (as compared to grade I or II) (uOR 2.45, 95 % CI 1.88 to 3.20), Grade IV injury (uOR 3.09, 95 % CI 2.20 to 4.35), polyarterial injury (uOR 3.11 (95 % CI 2.05 to 4.72), occurrence of hypotension at the time of hospital admission (adjusted odds ratio [aOR] 1.32, 95 % CI 0.87 to 2.03) and higher total body injury severity (aOR 5.91, 95 % CI 1.90 to 18.39). Conclusion: Local anatomical injury pattern, overall burden of injury and flow dynamics contribute to BCVI-related stroke risk. These findings provide the foundational evidence base for risk stratification to support clinical decision making and further research.