The devastating consequences if Blunt cerebrovascular injury is left undiagnosed.
Blunt cerebrovascular injury (BCVI) is defined as carotid or vertebral artery injury due to blunt trauma. There are several screening criteria that have been developed to screen for this injury, however many patients may not reliably be identified with these screening criteria.
Although this is not a common injury, its potential complications if undiagnosed and untreated can be devastating. The current screening criteria have been refined and expanded over the years, but just how good are they?
The authors of this trial, Leichtle SW, et al, were trying to determine if a universal screening protocol for BCVI with CTA of the neck for all major blunt trauma activations performs better than current established screening protocols.
The BCVI Grading Scale and Treatment Recommendations:
1 = Intimal irregularity with <25% narrowing (Single antiplatelet agent (Aspirin 81mg or 325mg))
2 = Dissection or intramural hematoma with >25% narrowing (Single antiplatelet agent (Aspirin 81mg or 325mg))
3 = Pseudoaneurysm (Dual antiplatelets or therapeutic anticoagulation (heparin drip with a PTT goal of 60 to 90))
4 = Occlusion (Dual antiplatelets or therapeutic anticoagulation used on case-by-case basis with input from neurosurgery)
5 = Transection with extravasation of contrast (OR)
This was a retrospective observational trial of adult blunt trauma activations at a single institution from July 2017 to August 2019 who underwent CT angiography of the neck. The authors calculated the sensitivity, specificity, PPV, NPV and accuracy of common screening criteria.
Of the participants, 4,659 patients fulfilled inclusion criteria and 126 patients (2.7%) had BCVIs. Among these, 61 patients (48%) had BCVI grade ≥3 and none had BCVI grade 5. Of the 158 BCVIs 91 (72%) would have met the screening criteria outlined in the ACS-TQIP Best Practices Guidelines in Imaging and 104 (83% would have met the screening criteria outlined in the expanded Denver criteria.
From there, 14 patients (23%) with a BCVI grade ≥3 would not have been captured by any screening criteria. Patients who did not receive treatment had a trend toward increased mortality 52.4% vs. patients who did receive treatment with a mortality of 4.8%.
Even though a larger number of patients in the no treatment group died from severe TBI, the study was not powered to compare complications between the different treatment regimens.
Many patients will have equivocal findings, which represent a real challenge as this can lead to excessive additional diagnostic workup or overtreatment. In this trial a 48-hour follow up CTA of equivocal findings, resulted in a final diagnosis in all but 0.6% of cases.
Although antithrombic therapy and anticoagulation sound counterintuitive in BCVI, its purpose is to reduce the rate of stroke. It does not necessarily decrease the progression of BCVI. A comparison of treatment regimens is difficult as every institution will have their own practice pattern (i.e. single vs. dual antiplatelets, 81mg vs. 325mg of aspirin, antiplatelet vs. heparin drip, and PTT goals).
The two most commonly used screening criteria, at this single institution missed almost 20% (one in five) of patients with BCVI. Although a rare diagnosis, missing it can be catastrophic for the patient. Universal CTA of the neck in hemodynamically stable blunt trauma patients will catch all BCVIs with a substantial benefit and very little harm.
Leichtle SW et al. Blunt Cerebrovascular Injury: the case for Universal Screening. J Trauma Acute Care Surg 2020. PMID: 32520898