Arterial wall properties in carotid artery dissection: an ultrasound study.

BACKGROUND: Cervical artery dissection is often attributed to an underlying arteriopathy related to a generalized extracellular matrix defect. OBJECTIVE: The authors compared the hemodynamic and morphologic properties of the carotid artery, as assessed noninvasively by ultrasonography, in patients with spontaneous internal carotid artery dissection (ICAD) and control subjects. METHOD: Twenty-six patients who experienced ICAD more than 6 months before evaluation were compared with 26 controls matched for age, sex, and height. Cases and controls had ultrasound measurement of common carotid artery diameter and diameter change during the cardiac cycle, bulbar and suprabulbar internal carotid artery diameters, and common carotid artery intima-media thickness. The unaffected carotid artery in cases was compared with the carotid artery of the same side in controls. RESULTS: Common carotid artery relative diameter change was significantly higher in cases than controls, whereas other measurements were not significantly different between the groups. In multivariate analyses, the highest tertile of common carotid artery relative diameter change was associated with the risk of ICAD (OR, 10.0; 95% CI, 1.8 to 54.2; p = 0.002) CONCLUSION: An underlying arteriopathy, presumably related to an extracellular matrix defect, may be present in patients with spontaneous ICAD.

Common carotid artery intima-media thickness and brain infarction : the Etude du Profil Génétique de l'Infarctus Cérébral (GENIC) case-control study. The GENIC Investigators.

BACKGROUND-The use of intima-media thickness (IMT) as an outcome measure in observational studies and intervention trials relies on the view that it reflects early stages of atherosclerosis and cardiovascular risk. There is little knowledge concerning the relation between IMT and brain infarction (BI). METHODS AND RESULTS-We investigated the relation of IMT with BI and its subtypes in 470 cases and 463 controls. Cases with BI proven by MRI were consecutively recruited and classified into subtypes by cause of BI. Controls were recruited among individuals hospitalized at the same institutions and matched for age, sex, and center. IMT was measured at the far wall of both common carotid arteries (CCA) using an automatic detection system. Adventitia-to-adventitia diameters and CCA-IMT were measured on transverse views; lumen diameter was computed using these measures. Mean (+/-SEM) CCA-IMT was higher in cases (0.797+/-0.006 mm) than in controls (0.735+/-0.006 mm; P<0. 0001). This difference remained after adjustment for lumen diameter and when analyses were restricted to subjects free of previous cardiovascular or cerebrovascular history. The difference in CCA-IMT between cases and controls was significant in the main subtypes. The risk of BI increased continuously with increasing CCA-IMT. The odds ratio per SD increase (0.150 mm) was 1.82 (95% confidence interval, 1.54 to 2.15); adjustment for cardiovascular risk factors slightly attenuated this relation (odds ratio, 1.73; 95% confidence interval, 1.45 to 2.07). CONCLUSIONS-An increased CCA-IMT was associated with BI, both overall and in the main subtypes. An increased IMT may help select patients at high risk for BI.

Use of monitoring software to improve the measurement of carotid wall thickness by B-mode imaging.

METHODOLOGY: High-resolution B-mode imaging is a reliable, easily performed and non-invasive means of studying atherosclerosis in superficial blood vessels. Recently it has been used for in vivo studies on the thickness of the common carotid artery wall. It is very sensitive, although the results of practical investigations are highly dependent on both the operator and the direction and angle of ultrasound beams directed towards the vessel. PROTOCOL: We have assessed inter- and intra-observer reproducibility of the measurement of common carotid artery wall thickness in 13 subjects, using two procedures. The first was a standard echographical investigation. In the second procedure, the principal parameters recorded from the first investigation were used to reposition the beam with the same incident angle. RESULTS: Intra-observer variability (correlation coefficient, r = 0.61 for procedure 1 and r = 0.77 for procedure 2) and inter-observer variation (r = 0.58 for procedure 1 and r = 0.71 for procedure 2) were reduced when the second investigation was assisted by reproducibility software. CONCLUSIONS: The proposed method is a reliable and reproducible way of assessing combined intimal and medial wall thickness in the common carotid artery. It may be possible to improve reproducibility using specific software to aid the operator. Since the intimal and medial thickness of the common carotid artery appears to be a sensitive marker of vascular risk, the proposed standardized method of measuring these parameter may allow early detection and assessment of changes.