Blunt Cerebrovascular Injuries (BCVIs): Morphological Insights Into Grade III Injuries

ObjectivesBlunt cerebrovascular injuries (BCVIs) carry significant morbidity due to the risk of ischemic stroke. Current screening and management guidelines do not account for injury morphology. Grade III pseudoaneurysms represent a distinct subset characterized by focal vessel wall disruption. This study aimed to characterize morphologic subtypes of grade III BCVI and evaluate their vascular impact.MethodsWe performed a single-institution retrospective review of patients with grade III BCVI diagnosed by computed tomography angiography between September 2020 and September 2021. Patients with penetrating trauma or grade I-II injuries were excluded. Lesions were characterized by anatomic location, morphology (saccular, fusiform, complex), maximal vessel diameter (percent enlargement), luminal compromise (percent narrowing), and presence of intimal flaps. Statistical analyses included chi-square tests, ANOVA, and regression modeling.ResultsThirty-one patients met inclusion criteria. Complex morphologies demonstrated significantly larger maximal diameters (mean 180%) than saccular (150%) and fusiform (140%) morphologies (P < 0.001). Luminal compromise also differed by morphology (P < 0.001), with complex (75%) and fusiform irregular (65%) lesions showing the greatest narrowing. Saccular regular injuries most often produced mild compromise (1-50%). No significant association was identified between bifurcation level and morphology, though saccular lesions appeared more common at C4.ConclusionsMorphologic subtypes of grade III BCVI demonstrate distinct vascular characteristics. Complex morphologies show greater vessel enlargement and luminal narrowing, suggesting higher risk for thrombotic complications and highlighting the potential role of morphology in BCVI risk stratification.