[Study of correlation between carotid artery tortuosity and atherosclerotic carotid artery stenosis].

Objective: To investigate the correlation between carotid artery tortuosity and atherosclerotic carotid artery stenosis. Methods: A total of 73 patients who underwent carotid computed tomography angiography with unilateral atherosclerotic carotid artery stenosis at Department of Neurosurgery of Beijing Hospital from January 2011 to June 2016 were retrospectively reviewed. There were 51 males and 22 females ranging from 48 to 90 years old, the average age was (65.9±9.5) years. There were 38 patients with carotid stenosis in the left carotid artery and 35 in the right, the stenosis degree of carotid artery ranged from 30% to 90% with the median was 44.0% (25.5%). According to the degree of carotid artery stenosis, the patients were classified into mild stenosis group and moderate/severe stenosis group. There were 43 patients in the mild stenosis group with an average stenosis degree of (37.5±5.4)%, there were 30 patients in moderate/severe stenosis group with an average stenosis degree of (65.6±10.9)%. The carotid artery (CCA) tortuosity, extracranial internal carotid artery (EICA) tortuosity and CCA-ICA bifurcation tortuosity were quantified by measuring the CCA tortuosity index, EICA tortuosity index and the internal carotid artery (ICA) angle, respectively. Comparison of diseased and normal carotid arteries was performed using t test or Wilcoxon signed-ranked test. Results: There were no statistically significant differences in CCA tortuosity index (Z=-0.584, P=0.559), ICA angle (t=0.278, P=0.781), and EICA tortuosity index (Z=-0.377, P=0.706) between diseased and normal carotid arteries in 73 patients. The diseased carotid arteries showed larger ICA angles (39.0° (19.0°) vs. 30.0° (15.0°)) (Z=-2.439, P=0.015) in the mild stenosis group, but smaller ICA angles ((31.5±11.7)° vs. (39.1±16.2)°) (t=-2.529, P=0.017) in the moderate/severe stenosis group, compared with the contralateral normal carotid arteries. There was no statistically significant difference in CCA (Z=-0.720, P=0.472; Z=-0.013, P=0.990) and EICA tortuosity index (Z=-0.349, P=0.727; Z=-0.114, P=0.909) between diseased and normal carotid arteries. Conclusions: Compared with normal carotid arteries, carotid arteries with mild atherosclerotic stenosis demonstrate a more tortuous CCA-ICA bifurcation, while those with moderate/severe stenosis demonstrate a straighter CCA-ICA bifurcation. There is no correlation between CCA, EICA tortuosity and carotid artery stenosis.