Persistent dissection of carotid artery in patients operated on for type A acute aortic dissection—carotid ultrasound follow-up

Abstract

Over a period of 5 years, 124 patients were operated on at the National Institute of Cardiology in Warsaw for acute aortic dissection, 27 of whom died. The 97 patients discharged from the hospital were included in the present analysis. The age of the patients ranged from 25 to 73 years with a mean of 50±10 years. Ultrasound examination of carotid arteries was performed with the patient lying on his back using a Toshiba 340A color Doppler system with a linear array probe of 7.5 MHz. Of the 97 patients examined, 15 (15%) had a dissection of at least one of the common carotid arteries (CCA). Two had Marfan syndrome. In 11 patients the dissection involved the right common carotid artery and in four it involved both the left and right common carotid arteries. The flow in the true lumen of CCA and ICA was preserved in all patients and the degree of narrowing ranged from 30 to −70%. Only one of the 15 patients with CCA dissection had an ipsilateral neurological deficit which was already present before the aortic aneurysm operation. Ultrasound follow-up was performed in all patients with the CCA dissection found on first examination. The mean duration of follow-up was 21 months. In 14 patients the degree and extent of the dissection as well as the narrowing of the true lumen was comparable, and in one patient the false channel closed spontaneously. During follow-up there were no new major neurological events despite the persistence of the CCA dissection with different degrees of narrowing of the true lumen. Doppler ultrasound examination of the carotid arteries can supply additional information about the extent of the dissection, and help to assess the flow in the persisting ‘double channel’ common carotid artery during the follow-up of patients.

Introduction

Acute aortic dissection is a dramatic medical emergency. Despite prompt surgical intervention in type A dissection, the mortality remains high. The etiology of the disease is multifactorial, often unknown, with a relatively high occurrence of Marfan syndrome in younger patients and arterial hypertension in older groups. Current methods of diagnosis include anamnesis, standard chest X-ray, standard (TTE) and transesophageal echocardiography (TEE), computed tomography, and magnetic resonance imaging.

The status of the patient at initial presentation forces only a brief diagnostic delay before surgical intervention is undertaken. Often, patients are operated upon directly after arrival from the referring hospital, leaving little time for additional diagnostic procedures. In our center, the decision is most often based on the results of TEE. In some patients who have undergone successful surgery under emergency conditions an ultrasound carotid examination performed days or weeks after the intervention reveals a unilateral or bilateral persistent dissection visible in the common carotid artery, sometimes forming part of a larger dissection of the arch and descending aorta. The problem of isolated carotid artery dissection is discussed extensively in the literature, but there is little data concerning aortic dissection extending to the carotid arteries [1], [2], despite its relatively high prevalence. The development of new diagnostic tools such as color-coded Doppler ultrasound and MRI techniques has led to renewed interest in this complication. This problem can be of interest for clinical decision making, especially when the involvement of carotid arteries and its extent is known before operation for aortic dissection. The extensive involvement of both carotid arteries can be additional evidence for the option of extensive aortic arch repair.