Clinical and radiographic outcomes following traumatic Grade 3 and 4 carotid artery injuries: a 10-year retrospective analysis from a Level 1 trauma center. The Parkland Carotid and Vertebral Artery Injury Survey
Authors: Scott William W. , Sharp Steven , Figueroa Stephen A. , Eastman Alexander L. , Hatchette Charles V. , Madden Christopher J. , Rickert Kim L. 
Published: December 2014

OBJECT
Screening, management, and follow-up of Grade 3 and 4 blunt carotid artery injuries (BCAIs) remain controversial. These high-grade BCAIs were analyzed to define their natural history and establish a rational management plan based on lesion progression and cerebral infarction.

METHODS
A retrospective review of a prospectively maintained database of all blunt traumatic carotid and vertebral artery injuries from August 2003 to April 2013 was performed, and Grade 3 and 4 BCAIs were identified. The authors define Grade 3 injuries as stenosis of the vessel greater than 50%, or the development of a pseudoaneurysm, and Grade 4 injuries as complete vessel occlusion. Demographic information, imaging findings, number of images obtained per individual, length of radiographic follow-up examination, radiographic outcome at end of follow-up period, treatment(s), and documentation of ischemic stroke or transient ischemic attack (TIA) were recorded.

RESULTS
Fifty-three Grade 3 BCAIs in 44 patients and 5 Grade 4 BCAIs in 5 patients were identified and had available follow-up information. The mean follow-up duration for Grade 3 BCAIs was 113 days, and the mean follow-up for Grade 4 BCAIs was 78 days. Final imaging of Grade 3 BCAIs showed that 53% of cases were radiographically stable, 11% had resolved, and 11% were improved, whereas 25% had radiographically worsened. In terms of treatment, 75% of patients received aspirin (ASA) alone, 5% received various medications, and 2% received no treatment. Eighteen percent of the patients in the Grade 3 BCAI group underwent endovascular intervention, and in all of these cases, treatment with ASA was continued after the procedure. Final imaging of the Grade 4 BCAIs showed that 60% remained stable (with persistent occlusion), whereas the remaining arteries improved (with recanalization of the vessel). All patients in the Grade 4 BCAI follow-up group were treated with ASA, although in 1 patient treatment was transitioned to Coumadin. There were 3 cases of cerebral infarction that appeared to be related to Grade 3 BCAIs (7% of 44 patients in the Grade 3 group), and 1 case of stroke that appeared to be related to a Grade 4 BCAI. All identified cases of stroke developed soon after hospital admission.

CONCLUSIONS
Although the posttraumatic cerebral infarction rate may be overestimated, the results of this study suggest that the Grade 3 and 4 BCAIs carry the highest stroke risk of the blunt cerebrovascular injuries, and those infarctions were identified on or shortly after hospital admission. Despite a 40% recanalization rate in the Grade 4 BCAI group and an 89% rate of persistent pseudoaneurysm in the Grade 3 BCAI group, follow-up imaging showed progressive worsening without radiographic improvement in only a small number of patients, and these findings alone did not correlate with adverse clinical outcome. Follow-up protocols may require amending; however, further prospective studies are needed to make conclusive changes as they relate to management.