Imaging analysis of ischemic strokes due to blunt cerebrovascular injury.

BACKGROUND: The timing of stroke onset among patients with blunt cerebrovascular injury (BCVI) is not well understood. All blunt trauma patients at our institution undergo a screening computed tomographic angiography (CTA) of the neck. Most patients with CTA evidence of BCVI are treated with aspirin, and all patients with clinical evidence of stroke are treated with aspirin and undergo magnetic resonance imaging (MRI) of the brain. We conducted a retrospective review to determine the incidence of stroke upon admission and following admission. METHODS: All neck CTAs and head MRIs obtained in blunt trauma patients were reviewed from August 2017 to August 2019. All CTAs that were interpreted as showing BCVI were individually reviewed to confirm the diagnosis of BCVI. Stroke was defined as brain MRI evidence of new ischemic lesions, and each MRI was reviewed to identify the brain territory affected. We extracted the time to aspirin administration and the timing of stroke onset from patients' electronic health records. RESULTS: Of the 6,849 blunt trauma patients, 479 (7.0%) had BCVIs. Twenty-four patients (5.0%) with BCVI had a stroke on admission. Twelve (2.6%) of the remaining 455 patients subsequently had a stroke during their hospitalization. The incidence of stroke among patients with BCVI was 7.5%; 2.6% were potentially preventable. Only 5 of the 12 patients received aspirin before the onset of stroke symptoms. All 36 patients with BCVI and stroke had thromboembolic lesions in the territory supplied by an injured vessel. CONCLUSION: With universal screening, CTA evidence of BCVI is common among blunt trauma patients. Although acute stroke is also relatively common in this population, two thirds of strokes are already evident on admission. One third of BCVI-related strokes occur after admission and often relatively early, necessitating rapid commencement of preventative treatment. Further studies are required to demonstrate the value of antithrombotic administration in preventing stroke in BCVI patients. LEVEL OF EVIDENCE: Prognostic and Epidemiologic; Level IV.

Universal screening for blunt cerebrovascular injury.

BACKGROUND: Blunt cerebrovascular injury (BCVI) can result in thromboembolic stroke. Many trauma centers selectively screen patients with cervical computed tomographic angiography (CTA) based on clinical criteria. In 2016, our institution adopted universal screening for BCVI for all blunt trauma patients. The aim of this study was to accurately determine the incidence of BCVI and to evaluate the diagnostic performance of the Denver criteria (DC), expanded Denver criteria (eDC), and Memphis criteria (MC) in selecting patients for screening. METHODS: Retrospective cohort study of adult (≥16 years) blunt trauma patients who presented to the Level I trauma center at University of Alabama at Birmingham. We reviewed all CTA reports and selected CTA images to obtain the true incidence rate of BCVI. We then evaluated the diagnostic performance of the DC, eDC, and MC. RESULTS: A total of 6,800 patients who had suffered blunt trauma were evaluated, of whom 6,287 (92.5%) had a neck CTA. Of these, 480 (7.6%) patients had CTA evidence of BCVI. The eDC identified the most BCVI cases (sensitivity 74.7%) but had the lowest positive predictive value (14.6%). The DC and MC had slightly greater positive predictive values (19.6% and 20.6%, respectively) and had the highest diagnostic ability in terms of likelihood ratio (2.8 and 2.9) but had low sensitivity (57.5% and 47.3%). Consequently, if relying on the traditional screening criteria, the DC, eDC, and MC would have respectively resulted in 42.5%, 25.3%, and 52.7% of patients with BCVI identified by universal screening not receiving a neck CTA to screen for BCVI. CONCLUSION: Blunt cerebrovascular injury is even more common than previously thought. The diagnostic performance of selective clinical screening criteria is poor. Consideration should be given to the implementation of universal screening for BCVI using neck CTA in all blunt trauma patients. LEVEL OF EVIDENCE: Diagnostic, level III.