Objective: Although different aortic arch classifications exist to help determine carotid artery stenting (CAS) difficulty, they are not validated. We compared quantitative angiographic characteristics of aortic arch between easy and difficult CAS.
Methods: We defined difficult procedures as requiring the longest fluoroscopy time (FT) (90th percentile) and easy procedures as the shortest FT (10th percentile) from our CAS database. We excluded patients undergoing additional procedures, intraprocedural complications or those with difficult vascular access.
Results: We analyzed 24 patients with difficult CAS (median fluoroscopy time of 58 minutes) and 24 with easy CAS (median fluoroscopy time of 19 minutes). The two groups were similar with respect to demographics, comorbidities and clinical presentation at the time of CAS. Patients with difficult procedures had a longer distance from the origin of treated artery to the beginning of the descending aorta (D1; 50 +/- 17 mm vs. 40 +/- 16 mm; p = 0.04), severe tortuosity (T) of the common carotid and internal carotid vessels (T; 50.0% vs. 16.7%; p = 0.03) and a trend in the presence of a Type 3 arch (33.3% vs. 25.0%; p = 0.18) and angulated takeoff (20.8% vs. 4.3%; p = 0.19). There was no difference in the severity of stenosis or index lesion calcification, ulceration and eccentricity between the two groups. On multivariate analysis, independent predictors of procedural difficulty were D1 (odds ratio 1.04 per mm; 95% CI, 1.01-1.09; p = 0.04), and T (odds ratio 4.77; 95% CI 1.3-42.9; p = 0.03).
Conclusions: Distance from the origin of the treated artery to the beginning of the D1 and target vessel T determine prolonged fluoroscopy time during CAS.