Effects of Cervical Rotation Angle on Atherosclerotic Internal Carotid Artery Blood Flow: A Safety Study Using an Animal Model of Internal Carotid Atherosclerosis

Abstract

ObjectiveThe aim of this study was to investigate the effects of the cervical rotation angle (CRA) on atherosclerotic internal carotid artery blood flow (ICA-BF) in an animal model. MethodsThirty healthy New Zealand white rabbits were included in the study. Twenty of the 30 rabbits were chosen randomly to be the model rabbits, and the remaining 10 were chosen to be the normal rabbits. The model rabbits’ left ICAs were treated by atherosclerosis modeling. The left ICAs of the model rabbits with atherosclerotic stenosis were chosen as the experimental group, and the right ICAs of the model rabbits without atherosclerotic stenosis were chosen as the control group. The left ICAs of the normal rabbits were chosen as the blank group. Using color duplex ultrasound, ICA-BF was measured in the artery contralateral to the direction of rotation in the positions of neutral (Pre-0°), 15°, 30°, 45°, 60°, 75°, 90°, and subsequent neutral (Post-0°). ResultsStatistically significant decreases were seen in ICA-BF after cervical spine rotation (from Pre-0° to 90°) in the control group only (P < .05). All the values of end-diastolic velocity in the experimental group were lower than those in the blank group at the same CRAs. The resistance index and pulsatility index of the experimental group were higher than those of the blank group except at 45° rotation. ConclusionIn our animal model, in the rabbits with hyperlipidemia but without atherosclerotic stenosis, CRA had the greatest impact on ICA-BF. Furthermore, at some of the same CRAs (especially neutral, 30°, and 60°), there were statistical differences in ICA-BF among the 3 groups.