Tortuosity and Proximal-Specific Hemodynamics Associated with Plaque Location in the Carotid Bulb Stenosis

BACKGROUND

Atherosclerotic plaque locations in the carotid bulb increasingly have been found to be associated with patterns of ischemic lesions and plaque progression. However, the occurrence of carotid bulb plaque is a complex process. We aimed to investigate plaque characteristics and geometric and hemodynamic parameters among patients with body and apical plaques of the carotid bulb and to identify the mechanism of bulb plaque formation and location.

METHODS

Consecutive patients with single carotid bulb stenosis (50-99%) were enrolled retrospectively. Patients were divided into body and apical plaque groups based on plaque location. Plaque location and characteristics were identified and measured on high-resolution vessel wall magnetic resonance imaging. Geometric parameters were derived from time-of-flight magnetic resonance imaging. Computational fluid dynamics simulations were performed to quantify wall shear stress (WSS) and four associated WSS-based metrics on the plaque side, on the non-plaque side, and in different parts of the lesion. Plaque characteristics and geometric and hemodynamic parameters were compared, and their associations with the plaque location were determined.

RESULTS

Seventy patients were recruited (41 body plaques and 29 apical plaques). WSSplaque values were lower than WSSnon-plaque values for all plaques (median [interquartile range], 12.59 [9.83-22.14] vs. 17.27 [11.63-27.63] Pa, p = 0.001). In a multivariate binary logistic regression, the tortuosity of the stenosed region, the magnitudes of the mean relative residence time, and the minimum transverse WSS in the proximal part of the lesion were the key factors independently associated with plaque location (p = 0.022, 0.013, and 0.012, respectively).

CONCLUSIONS

Plaque formation was associated with the local flow pattern, and the tortuosity and proximal-specific hemodynamics were significantly associated with plaque location in the carotid bulb.

Atherosclerosis of the carotid bulb is associated with the severity of orthostatic hypotension in non-diabetic adult patients: a cross-sectional study

BACKGROUND

The carotid bulb has a high density of baroreceptors that play an important role in maintaining blood pressure. We hypothesized that atherosclerosis of the carotid bulb would reflect the severity of orthostatic hypotension more accurately than would atherosclerosis of other carotid artery segments.

METHODS

This cross-sectional study included 198 non-diabetic adults. We measured the cardio-vascular ankle index as an index of arterial stiffness, intima-media thickness in each carotid artery segment (internal carotid artery, carotid bulb, distal and proximal portions, respectively, of the common carotid artery) as a measure of atherosclerosis, and heart rate variability as a measure of cardiac autonomic function. The sit-to-stand test was used to assess severity of orthostatic hypotension.

RESULTS

Intima-media thickness of the carotid bulb was correlated with orthostatic systolic blood pressure change (r = -0.218, p = 0.002), cardio-ankle vascular index (r = 0.365, p < 0.001) and heart rate variability parameters. Multivariate regression analysis revealed that among all of the segments, only intima-media thickness of the carotid bulb was an independent predictor of orthostatic systolic blood pressure change (p = 0.022).

CONCLUSION

Atherosclerosis of the carotid bulb was associated with severity of orthostatic hypotension, arterial stiffening and cardiac autonomic dysfunction than that of other carotid artery segments.

A Case of Anomalous Origin and Course of Vertebral Artery in a Patient with Klippel Feil Syndrome

Patients with Klippel-Feil syndrome (KFS) have an increased incidence of vascular anomalies as well as vertebral artery (VA) anomalies. In this article, we presented imaging findings of a 15-year-old female patient with KFS with a rare association of extraforaminal cranially ascending right VA that originated from the ipsilateral carotid bulb. Trifurcation of the carotid bulb with VA is a very unusual variation and to the best of our knowledge, right-sided one has not been reported in the literature.