Purpose: The etiology of coiling (i.e. severe elongation) of the extracranial part of the internal carotid artery (ICA) is poorly understood with the proposed etiology being congenital, atherosclerotic or hypertension. The objective was to investigate the association of coiling with hypertension, carotid artery atherosclerosis and other cardiovascular risk factors.
Methods: A case control study was performed in patients suspected of stroke, with (cases) or without (controls) coiling of the ICA determined on compute tomography angiography (CTA). Baseline characteristics included age, gender, hypertension, diabetes, smoking and hypercholesterolemia. Coiling of the ICA and atherosclerotic plaque at the carotid bifurcation were assessed on CTA. Logistic regression analyses were conducted.
Results: Coiling was identified in 108 patients with a median age of 71 years. Cases were compared with 256 controls with a median age of 69 years. Hypertension was present in 63% of the patients with coiling compared to 51% in the control group. Univariable analysis showed that hypertension was significantly associated with coiling, with an odds ratio of 1.65 (95% confidence interval (CI) 1.04-2.61, p = 0.034). Multivariable analysis corrected for age and sex resulted in an odds ratio of 1.71 (95% CI 1.05-2.80, p = 0.032), while correcting for atherosclerotic plaque at the bifurcation yielded an odds ratio of 1.63 (95% CI 1.00-2.66, p = 0.049). Age and atherosclerotic plaque were not significantly associated with coiling.
Conclusion: The main finding of this study was the significant association of hypertension with coiling of the ICA and the absence of an association with age, plaques and atherosclerotic risk factors other than hypertension.
Keywords: Coiling; Dolichoarteriopathy; Hypertension; Internal carotid artery; Tortuosity.