Age-related geometric analysis of the extracranial artery for endovascular access planning.

Background: Age-related geometric remodeling of the extracranial carotid arteries significantly influences hemodynamics and endovascular accessibility, yet comprehensive data covering the entire supra-aortic route remain limited. The objective of this study was to investigate these age-related geometric changes from the aortic arch to the proximal internal carotid artery (ICA) using computed tomography angiography (CTA), and to assess their association with vascular aging. Methods: This retrospective cross-sectional study included 485 patients who underwent CTA between January 2020 and December 2022. The participants were divided into two age groups: young (<60 years) and old (>70 years). Patients with carotid plaques or stenosis were excluded. Using semi-automated segmentation techniques, we analyzed geometric parameters, including vascular tortuosity, maximal diameter, cross-sectional area, and bifurcation angles from the aortic arch to the proximal ICA. Results: Out of the 485 participants, 257 (53%) were included in the old age group (mean age: 78.77±0.36 years). Vascular tortuosity from the common carotid artery (CCA) to the carotid artery bifurcation (CAB) was significantly higher in the old age group on both sides (right: 0.15±0.01 vs. 0.07±0.00; left: 0.14±0.01 vs. 0.06±0.00; P<0.001). The maximal diameters and cross-sectional areas of the common and internal carotid arteries also increased significantly with age CCA diameter (right: 7.49±1.05 vs. 7.25±1.05 mm; ICA cross-sectional area, right: 25.55±5.15 vs. 20.06±4.51 mm2; P<0.001). Furthermore, the CAB angle was markedly elevated bilaterally in older individuals (right: 33.52°±16.04° vs. 26.3°±15.86°; left: 35.94°±16.14° vs. 29.36°±13.97°; P<0.001). Conclusions: Geometric changes in extracranial carotid arteries, including increased tortuosity, diameter, cross-sectional area, and bifurcation angle, are strongly associated with aging. These findings highlight the potential of CTA-based vascular geometry as a non-invasive imaging biomarker for assessing vascular aging and early structural remodeling.