Patient Preparation
Anesthesia
Both local/regional anesthesia and general anesthesia have been used for eversion carotid endarterectomy (eCEA); which approach is preferable in this setting remains a matter of debate. Data from several randomized trials comparing regional and general anesthesia, including an international multicenter randomized trial of 3526 patients from 24 countries, have shown that the choice of anesthesia does not independently predict the outcome of the operative procedure. [28, 29, 30, 31]
Subsequent analysis of data from the same database showed that in patients for whom either anesthetic approach was clinically indicated, cost-effectiveness analysis favored local anesthesia. [32] Ultimately, the surgeon, in consultation with the anesthesiologist and the patient, must make the final decision regarding the best anesthetic management in each case.
If local or regional anesthesia is selected, mild sedation may be administered, but the patient must be alert enough to be evaluable for neurologic changes. Usually, two or three simple questions are agreed on with the patient in advance and then repeated during carotid cross-clamping. Drapes may be suspended above the patient’s head on a Mayo stand to create more space for the patient.
Generally, regional anesthesia is optimal in calm patients with slender and mobile necks; it may be less successful in patients who are claustrophobic or anxious, have high lesions or immobile necks, or have previously undergone carotid endarterectomy (CEA).
Positioning
The patient is placed in the supine position with the neck hyperextended (see the image below). Once the neck is hyperextended, the head is rotated 15-20º away from the side of the lesion to face the opposite side. This maneuver moves the mandible superiorly, exposes the mediolateral aspect of the neck, and opens up the angle of access to the anterior neck triangles on the side of the lesion. Folded sheets may be placed under the shoulders, or a tape may be placed across the patient’s forehead and secured at the edges of the table.
Patient is placed in supine position with hyperextension of neck. Head is rotated 15-20° away from operating side to face contralateral to side of lesion. This maneuver is used to move mandible superiorly, to expose mediolateral aspect of neck, and to open up angle of access to anterior neck triangles at side of lesion.
Proper positioning is important because excessive hyperextension of the neck can tighten the sternocleidomastoid muscle and restrict the mobility of the common carotid artery (CCA) and the carotid bifurcation, thereby making exposure of the lesion more difficult. Another reason for avoiding extensive hyperextension of the neck is to ensure that the internal jugular vein (IJV) remains lateral, rather than anterior, to the carotid artery.
Because cervical arthritis is prevalent in the age group for which eCEA is most commonly indicated, the neck must be carefully manipulated and slowly hyperextended at the craniocervical joint. Introducing some degree (10-20°) of reverse Trendelenburg is useful for maximizing exposure, reducing venous pressure and congestion, and minimizing bleeding.
After proper positioning, a topical antiseptic agent is carefully applied to the neck with minimal pressure (to avoid dislodging emboli from the carotid plaque). The operating area is cordoned off with four sterile drapes (see the image below). Incorporating the ear lobe and mastoid process (superiorly) and the neck midline (medially) and the sternoclavicular joint (inferiorly) into the surgical field is essential. A single weight-based dose of an intravenous antibiotic (cefazolin) is administered within 1 hour of making the incision.
Operating area is cordoned off with 4 sterile drapes. It is essential to incorporate ear lobe and mastoid process (superiorly), neck midline (medially), and sternoclavicular joint (inferiorly) into surgical field.
Monitoring & Follow-up
If the patient is afebrile, neurologically intact, and hemodynamically stable, he or she may safely be discharged on postoperative day 1. Before discharge, the neck is examined and the Blake drain removed. The patient is instructed to return if any problems develop and given detailed discharge instructions. A routine follow-up visit is scheduled 4 weeks after the operation; this visit should include carotid duplex evaluation.
The 2018 guidelines from the Society for Vascular Surgery (SVS) recommended that after CEA, surveillance with duplex ultrasonography (US) should be carried out at baseline and every 6 months for 2 years and annually thereafter until the patient is stable. [33] The first duplex study should be done soon after the procedure (preferably ≤ 3 months) to establish a posttreatment baseline. Surveillance should be maintained at some regular interval (eg, every 2 years) for the life of the patient.
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Underlying etiology of carotid artery stenosis is formation of atheromatous plaque at bifurcation of common carotid artery and in origins of internal carotid artery.
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A. Simplified flow patterns at carotid bifurcation demonstrate complex reversal of flow along posterior wall of carotid sinus. This region is most vulnerable to plaque development. B. Established plaque at carotid bifurcation. C. Soft, central necrotic core with overlying thin fibrous cap. This area is prone to plaque rupture. D. Disruption of fibrous cap allows necrotic cellular debris and lipid material from central core to enter lumen of internal carotid artery, thus becoming atherogenic emboli. Patient may experience symptoms (transient ischemia, stroke, or amaurosis fugax) or remain asymptomatic, depending on site of lodgment and extent of tissue compromise. E. Empty necrotic core becomes deep ulcer in plaque. Walls of ulcer are highly thrombogenic and reactive with platelets. This leads to thromboembolism in internal carotid artery circulation.
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North American Symptomatic Carotid Endarterectomy Trial (NASCET) criteria. Convention for describing carotid stenosis is to compare lumen diameter at most narrow point to diameter of internal carotid artery in normal segment several centimeters distal to stenosis.
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A. Arterial flow (red) is displayed in internal carotid artery (ICA) and common carotid artery (CCA). Sampling for flow velocities and spectral waveform analysis is carried out in center stream of ICA, and waveform is shown below. Peak systolic and end-diastolic velocities are measured on representative wave. B. Same general area is being interrogated in diseased ICA. Lumen appears to narrow, and red color becomes variegated and lighter. Arterial flow is sampled in area of maximal disturbance and narrowing, and resultant waveform is displayed below.
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Representative image of extracranial circulation obtained with CT angiography and 3-dimensional reconstruction. Arrow points to stenosis in left internal carotid artery.
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Patient is placed in supine position with hyperextension of neck. Head is rotated 15-20° away from operating side to face contralateral to side of lesion. This maneuver is used to move mandible superiorly, to expose mediolateral aspect of neck, and to open up angle of access to anterior neck triangles at side of lesion.
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Operating area is cordoned off with 4 sterile drapes. It is essential to incorporate ear lobe and mastoid process (superiorly), neck midline (medially), and sternoclavicular joint (inferiorly) into surgical field.
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Incision is created over anterior border of sternocleidomastoid muscle, along line connecting sternocleidoclavicular junction with processus mastoideus, preserving great auricular nerve superiorly and carried down to carotid sheath. This is the position of the incision for optimal exposure of common carotid artery, internal carotid artery, and external carotid artery.
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Skin incision is deepened through subcutaneous fat and platysma. Platysma is divided longitudinally. This gains access to investing layer of deep cervical fascia, which is incised along anterior border of sternocleidomastoid muscle.
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Sternocleidomastoid muscle is retracted posteriorly to expose carotid sheath.
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Dissection of carotid sheath is carried low on neck, along medial aspect of internal jugular vein. Initial incision of carotid sheath should be performed carefully to avoid injury to vagus nerve, which is located anterior to carotid artery 10% of time.
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Facial vein is landmark for carotid bifurcation in vast majority of patients. It courses across common carotid artery and drains into internal jugular vein. Facial vein is mobilized, suture-ligated, and divided.
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After division of common facial vein, internal jugular vein is retracted laterally to yield clear exposure of underlying common carotid artery and internal carotid artery.
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Circumferential exposure of common carotid artery is required only for arterial segment where vessel loops are to be placed; great care must be taken posteriorly, where vagus nerve is anticipated to be encountered in majority of patients.
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External carotid artery is dissected free of surrounding tissue and encircled with colored vessel loop, as is proximal superior thyroid artery. Internal carotid artery lies posterolaterally in carotid sheath.
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Common facial vein branch of internal jugular vein marks site of carotid bifurcation. After division of facial vein, internal jugular vein is retracted posteriorly to expose carotid bifurcation. Before mobilization of internal carotid artery, hypoglossal nerve should be identified and preserved.
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Transection of internal carotid artery (ICA) is performed with pair of Stephens scissors. Crook of scissors is placed at carotid bifurcation with blades oriented inferolaterally to encircle artery. ICA is transected with sharp, oblique, and complete cut.
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Transection of internal carotid artery (ICA) will lead to exposure of atheromatous plaque within ICA lumen.
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Under direct vision, plaque is reached with DeBakey forceps. With gentle and constant downward traction on plaque (top), outer arterial layer of internal carotid artery (ICA) is peeled back (everted) to deliver plaque (middle). Eversion should be maintained with forceps holding edges of transected artery constantly (bottom). This will allow facilitated manipulation of transected arterial end and subsequent anastomosis of proximal ICA with common carotid artery.
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Extraction of atheromatous plaque from internal carotid artery.
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After extraction of atheromatous plaque, everted edges, as well as lumen of proximal internal carotid artery, are carefully inspected for residual debris and well irrigated with heparinized saline.
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After plaque extraction from internal carotid artery, attention is directed to common carotid artery and external carotid artery. Optimal plane of dissection lies between intima and circular fibers of media. This endarterectomy plane allows smooth distal tapering of endpoint.
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Spatula is passed behind plaque to isolate it from adventitial plane on opposite side of common carotid artery.
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After plaque extraction, lumen and edges of common carotid artery and external carotid artery are thoroughly inspected for residual atheromatous plaques and any debris and generously irrigated with normal saline.
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Double-armed continuous 6-0 polypropylene suture is used for end-to-side anastomosis.
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Creation of end-to-side anastomosis (using "heel first, toe last" technique) begins with stitch at proximal end of the artery (heel), with one arm penetrating through transected internal carotid artery and other arm through proximal bifurcation.
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Back wall of anastomosis is completed with continuous suture ending in internal carotid artery.
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Front wall of anastomosis is completed in same manner as back wall, from distal to proximal.
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Before completion of arterial closure, each clamp is released individually to flush out any residual debris.
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Newly created anastomosis. Duplex ultrasonography is performed to verify technical result of procedure and to assess patency of carotid vasculature.
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Before closure is begun, Blake drain is placed through separate stab incision.
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Only deep layer to be approximated is platysma. Platysma is closed with 2-0 monofilament absorbable suture.
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For closure of skin, subcuticular technique with 4-0 monofilament absorbable suture is used; this provides skin closure with excellent cosmetic results.
