頚部頚動脈病変に対する超音波法の追跡調査

Abstract

The value of B-mode and color Doppler ultrasonography for follow-up of cases of carotid artery disease was investigated between January 1995 and January 1999. The subjects comprised 23 patients, including 22 males and one female. The mean age of the patients was 68.0 ± 6.5 years, the times of measurement ranged from 2 to 6, and the mean follow-up period was 18.0 ± 13.2 months. Two different groups were analyzed: a surgical group (n=15), including nine patients with carotid endarterectomy, three with percutaneous transluminal angioplasty, and three with extracranial-intracranial bypass, and a medical group (n=8), including six patients with cerebral infarction, one with moyamoya disease, and one with carotid artery aneurysm. Echogenicity of the plaque, stenotic rate of the carotid artery, peak flow velocity, end diastolic flow velocity, mean flow velocity, and pulsatility index (PI) in the common carotid artery (CCA), internal carotid artery (ICA) and external carotid artery were measured by B-mode and color Doppler ultrasonography. In the surgical group, both proximal PI and Δ PI (PI (CCA) -PI (ICA) ) in the CCA were lower postoperatively, but the distal PI in the ICA was higher postoperatively. One patient with severe carotid artery stenosis, which developed due to occlusion in the medical group, demonstrated an increased postoperative PI value in the CCA and ΔPI, and demonstrated a decreased postoperative PI in the ICA. ΔPI values showed more change than PI values. A follow-up study using combined B-mode and color Doppler ultrasonography is warranted to evaluate the changes in carotid plaque. In this study, ΔPI was found to be more sensitive than the other parameters.