Ultrasonic imaging of common carotid artery dissection

Abstract

Carotid artery dissection is a rare cause of cerebral vascular insufficiency. It is usually due to extension of the dissection in the aortic arch' and less commonly to isolated spontaneous dissection in the carotid Although noninvasive evaluation using pulsed Doppler techniques or oculoplethysmography may reveal secondary flow disturbance^,^,^ contrast angiography is still the standard test to confirm the diagnosis and outline the anatomy. We present a case of carotid dissection diagnosed by real-time ultrasonography in a patient who had a previous aortic arch dissection. CASE REPORTA 68-year-old woman was seen because of episodes of blurred vision in the right eye and transient weakness in the right leg. Nine months earlier, the patient underwent repair of a DeBakey type I aortic arch dissection. At that time aortic angiograms revealed a circumferential aortic dissection starting 2 cm above the aortic annulus. Operative repair was performed using a dacron graft. The postoperative course was uneventful. On physical examination, the patient was alert. Her blood pressure was 100/60 in the right arm and 160/60 in the left arm. Pulse rate was 70 beatdminute and regular. Carotid pulses were brisk and symmetrical. Palpable thrills and audible bruits were present in both sides. The apical impulse was hyperactive and displaced laterally. Auscultation revealed a fourth heart sound, a grade 3/6 ejection precordial murmur, and a grade 2/6 diastolic parasternal murmur. Neuro- (Fig. l), an image quite typical of arterial dissection. The abnormality involved the common bulb and the internal carotid artery as well. Ultrasonography of the left carotid artery revealed a severe stenotic lesion in the left internal carotid artery. Aortic arch angiography disclosed the postoperative changes in the aortic arch and dissection of the right common carotid artery extending into and terminating at the internal carotid artery (Fig. 2). Stenosis of the left carotid artery was also apparent. Since symptoms were attributable to the left carotid obstruction, endarterectomy of this artery was performed while dissection of the right carotid artery was treated conservatively with propranolol20 mg every 6 hours. The patient did well after the operation without recurrence of neurological symptoms. DISCUSSION

Doppler color flow imaging of common carotid artery dissection

“…CCA dissection may cause transient ischemic attacks or stroke but in contrast to ICA dissection Horner's syndrome and hemicrania have not been reported [1,[3][4][5].…”

“…This feature was present in 69% of a group of 22 patients with angiographically confirmed ICA dissections [6]. (2) [1,2,5]. Pathophysiologically this condition may either be directly related to the aortic dissection in a continuously mediated form or it may only be temporally related in a discontinuous form, the mechanisms of which are yet unknown [12].…”

“…Reports of CCA dissections demonstrating the visualization of an intravascular double lumen in B-mode echotomograms are surprisingly rare [3][4][5]. Since the majority of patients with a CCA dissection remain neurologically asymptomatic and the diagnosis may be missed by standard aortography and thoracic computed tomography, ultrasound examination of the carotid arteries in patients with aortic arch dissections are not often performed.…”

“…It occurred in 75 of 398 cases of aortic dissection in the study of Hirst et al [1] and in four of 31 cases in that of Dalen et al [2]. Although the diagnosis of CCA dissection is of special relevance in the patients' management, ultrasound studies such as B-mode echotomography and duplex sonography have been reported in only a limited number of cases [3][4][5]. This contrasts with the increasing number of dissections of the internal carotid artery (ICA) diagnosed by non-invasive methods [6].…”

Cervicocranial Artery Dissection

“…The correct diagno sis was previously established by conventional angiography alone (1,4,9,11), but in recent years Doppler ultrasound has been introduced as an alter native in diagnosing cervicocranial artery dissection (3,8,13,27,29,30). However, many centers still do angiography for confirmation of this diagnosis, and although digital subtraction angiography (DSA) is performed with few complications, noninvasive methods are preferable (6-8, 14-16, 18-20).…”