External Carotid Artery Hemodynamics Could Be Useful In Detecting Significant Internal Carotid Disease
Jason Zakko, MD, Kejal Shah, MD, Laureen Baetz, RT, RVT, Bhagwan Satiani, MD, MBA, Mounir J. Haurani, MD.
Ohio State University Wexner Medical Center, Columbus, OH, USA.
OBJECTIVES: The external carotid artery (ECA) is often regarded as clinically insignificant leading to a paucity of data regarding validated ECA criteria or association between ECA velocities and internal carotid artery (ICA) stenosis by duplex ultrasound scanning (DUS). This information may have clinical utility in patients with suboptimal duplex visualization of the ICA or ambiguous DUS findings. Our objective was to correlate ECA hemodynamics with known ICA disease by DUS to assist clinicians when ICA disease cannot be reliably quantified.
METHODS: A retrospective chart review was performed for patients who had carotid DUS as well as confirmatory testing (angiography, CT angiogram, magnetic resonance angiogram) at a single academic medical center from 1/1/2005 to 12/31/2017. ICA stenosis was grouped into 4 categories (0=<50% stenosis, 1=50-69%, 2=70-99%, 3=100%) based on validated DUS criteria. Vessels with previous endarterectomy or stenting were excluded. ECA peak systolic velocities (PSV) were analyzed in addition to degree of ICA stenosis from the same DUS study. Pearson’s and ANOVA testing were performed using GraphPad Prism (GraphPad Software Inc., La Jolla, CA).
RESULTS: 249 carotid arteries were reviewed and 218 vessels were included. Average age of our patients was 68 (SD=10.1), and 61% were male. ECA PSV data for each category of ICA stenosis is summarized (Figure 1): ICA group 0 = PSV mean of 119.9 cm/sec (SD 55.6); Group 1 = PSV mean of 200.4 (SD 145.4); Group 2 = PSV mean of 167.7 (SD=94.8); and Group 3 = PSV mean 155.5 (SD=51.8). Using Pearson’s correlation, a statistically significant correlation was seen between ICA stenosis and ECA velocity (r=0.1975; p=0.0034). Performing a one-way ANOVA with Tukey’s testing demonstrated a statistically significant difference in ECA velocities between ICA stenosis groups 0 and 1 (mean diff. -84.05 cm/s; 95% CI (-135, -33.1); p=0.0002); and 0 vs 2 (mean diff. -51.37 cm/s; 95% CI (-89.6, -13.1); p=0.0034).
CONCLUSIONS: The data suggests a statistically significant correlation between ECA PSV and degree of ICA stenosis. Further data with a larger sample size and confirmatory studies are needed. However, this analysis suggests a role for estimating degree of ICA stenosis based on ECA velocities. 
Back to 2019 ePosters