Anatomic criteria in the selection of treatment modality for atherosclerotic carotid artery disease

Abstract

Objective: Three procedures are currently available to treat atherosclerotic carotid artery stenosis: carotid endarterectomy (CEA), transfemoral carotid artery stenting (TF-CAS), and transcarotid artery revascularization (TCAR). Although there is considerable debate evaluating each of these in a head-to-head comparison to determine superiority, little has been mentioned concerning the specific anatomic criteria that make one more appropriate. We conducted a study to define anatomic criteria in relation to inclusion and exclusion criteria and relative contraindications.

Methods: A retrospective review was conducted of 448 carotid arteries from 224 consecutive patients who underwent a neck and head computed tomography arteriography (CTA) scan before carotid intervention for significant carotid artery stenosis. Occlusion of the internal carotid artery (ICA) occurred in 15, yielding 433 arteries for analysis. Anatomic data were collected from CTA images and demographic and comorbidities from chart review. Eligibility for CEA, TF-CAS, and TCAR was defined on the basis of anatomy, not by comorbidity.

Results: CTA analysis revealed that 92 of 433 arteries (21%) were ineligible for CEA because of carotid lesions extending cephalad to the second cervical vertebra. Overall, 26 arteries (6.0%) were not eligible for any type of carotid artery stent because of small ICA diameter (n = 11), heavy circumferential calcium (n = 14), or combination (n = 1). An additional 126 arteries were ineligible for TF-CAS on the basis of a hostile aortic arch (n = 115) or severe distal ICA tortuosity (n = 11), yielding 281 arteries (64.9%) that were eligible. In addition to the 26 arteries ineligible for any carotid stent, TCAR was contraindicated in 39 because of a clavicle to bifurcation distance <5 cm (n = 17), common carotid artery diameter <6 mm (n = 3), or significant plaque at the TCAR sheath access site (n = 20), yielding 368 arteries (85.0%) that were eligible for TCAR.

Conclusions: A significant proportion of patients who present with carotid artery stenosis have anatomy that makes one or more carotid interventions contraindicated or less desirable. Anatomic factors should play a key role in selecting the most appropriate procedure to treat carotid artery stenosis. Determination of superiority for one procedure over another should be tempered until anatomic criteria have been assessed to select the best procedural options for each patient.

Keywords: CT angiography; Carotid artery disease; Carotid endarterectomy; Carotid stent; Transcarotid revascularization.