SURGICAL CONSIDERATIONS
Gary K. Steinberg
Robert L. Dodd
Description: Carotid endarterectomy (CEA) is frequently used to treat severe atherosclerotic occlusive disease involving internal carotid arteries at the common carotid artery bifurcation. Atherosclerotic carotid artery disease commonly causes thromboembolic or hemodynamic stroke and transient ischemic attacks (TIAs). Recent studies proved the efficacy of this operation, compared with medical treatment for symptomatic high-grade stenosis (70-99%), symptomatic moderate stenosis (50-69%), and asymptomatic high-grade stenosis (≥ 60%).
The operation involves opening the common carotid artery and the proximal internal carotid artery in the neck (
Fig 1.4-1), removing atherosclerotic plaque from the inside the artery, and repairing the wall of the arteries (media and adventitia). Opening the carotid artery (
arteriotomy) requires temporary occlusion of the proximal common carotid artery, distal internal carotid artery, external carotid artery, and, usually, its first branch, the superior thyroid artery. The entire procedure can be achieved under continued occlusion of these vessels if the collateral blood flow to the territory supplied by the occluded internal carotid is deemed adequate (on the basis of intraop EEG monitoring, internal carotid artery back-bleeding, stump pressures, CBF studies, or angiography). Alternatively, an internal shunt between the proximal common carotid artery and distal internal carotid artery can be placed after the arteriotomy for use during the endarterectomy. Often a synthetic graft (e.g., Dacron) or, occasionally, a vein graft, is used to reconstruct (“patch”) the arteriotomy site and increase the luminal diameter.
Variant Procedure or Approaches: The vascular surgeon’s approach to CEA is described in
Chapter 6.3. Carotid stenting is described in the Interventional Neuroradiology, Section 13.1. Stenting appears to be inferior to CEA in
outcome studies (↑ stroke, ↑ death) but is associated with ↓MI. EC-IC bypass for treatment of carotid occlusion is described in Section 1.1.
Usual preop diagnosis: Stroke; TIAs; carotid artery stenosis; carotid artery dissection
ANESTHETIC CONSIDERATIONS
(Procedure covered: carotid endarterectomy)
PREOPERATIVE
The incidence of occlusive or ulcerative lesions of the extracranial or intracranial vasculature increases with advancing years. Generally, these lesions are asymptomatic until the cross-sectional area of the vessel is decreased by at least 50%. This is because in most patients the cerebral vasculature has excellent collateral circulation, most important the circle of Willis (normal in only 50% of patients), but also persistent anastomoses from the basilar artery, and extra-to intracranial collateral flow via the ophthalmic artery or branches of the vertebral artery. Patients presenting for CEA generally fall into one of three categories: (1) Those with TIAs, presenting with symptoms that may be focal or generalized. (2) Patients with completed stroke. If the stroke is recent (< 2-4 wk), some surgeons will not operate on the patient for fear of converting an ischemic infarct into a hemorrhagic infarct; however, if the infarct is small and clinical deficit minor, early surgery may be indicated. Angiographic evaluation usually demonstrates a stenotic and/or ulcerative lesion at the carotid bifurcation. (3) Patients with asymptomatic bruit, which usually is found during a routine physical examination of the neck. These are of concern because they may signal the development of carotid stenosis and may benefit from surgical intervention.
