INTRODUCTION — Treatment aimed at carotid atherosclerotic lesions may be beneficial for symptomatic or asymptomatic patients. This topic will review the preoperative evaluation and surgical technique of carotid endarterectomy (CEA). The indications for carotid revascularization and perioperative stroke risk assessment for patients with carotid atherosclerosis are discussed elsewhere. (See "Management of asymptomatic extracranial carotid atherosclerotic disease" and "Management of symptomatic carotid atherosclerotic disease".)

Carotid artery stenting is also discussed separately. (See "Overview of carotid artery stenting".)

CAROTID ATHEROSCLEROTIC DISEASE — The effectiveness of CEA in the management of selected patients with symptomatic or asymptomatic carotid atherosclerotic disease has been established by large randomized clinical trials. The specific indications for CEA are discussed in detail elsewhere. (See "Management of asymptomatic extracranial carotid atherosclerotic disease", section on 'Carotid endarterectomy' and "Management of symptomatic carotid atherosclerotic disease", section on 'Patients appropriate for CEA'.)

Special considerations

Bilateral carotid stenoses — Some patients have varying degrees of bilateral carotid disease. No randomized clinical trials have evaluated the effectiveness of bilateral CEA for such patients. However, bilateral carotid occlusive disease appears to increase the risk for complications during and after unilateral CEA (whichever of the two carotids is treated first) [1-5]. In a follow-up analysis of the North American Symptomatic Carotid Endarterectomy Trial (NASCET), the risk of stroke was significantly increased for a severely stenosed ipsilateral carotid artery associated with an occluded contralateral carotid artery [4]. In spite of higher perioperative morbidity in the presence of an occluded contralateral artery, the longer-term outlook for patients who had endarterectomy performed for a recently symptomatic, severely stenosed ipsilateral carotid artery was better compared with medically treated patients. The impact of bilateral disease appears to be greater for CEA compared with carotid stenting. In a systematic review and meta-analysis, patients with contralateral carotid occlusion had a significantly higher rate of cerebral events and death for CEA compared with carotid artery stenting (16.2 versus 2.6 percent) [5].

The impact of severe contralateral carotid artery stenosis or occlusion on the benefit and risk of unilateral CEA in patients with symptomatic and asymptomatic disease is discussed in more detail separately. (See "Management of symptomatic carotid atherosclerotic disease", section on 'Factors influencing benefit and risk'.)

A combined approach (ie, bilateral repair during a single operation) is generally contraindicated due to the risks associated with respiratory compromise secondary to neck hematomas or recurrent laryngeal nerve injury, frequent difficulty with blood pressure control after manipulation of the carotid sinus, and concerns about cerebral hyperperfusion syndrome and the unknown effect of bilateral cerebral ischemia (although temporary). (See 'Perioperative morbidity and mortality' below.)

When the extent of contralateral carotid disease is significant enough to warrant bilateral CEA, most surgeons use a staged approach. When one side is symptomatic and the other asymptomatic, the symptomatic lesion is generally addressed first and the asymptomatic side addressed once the patient has recovered from the first CEA. If both sides are asymptomatic and of similar severity, the lesion supplying the dominant hemisphere is addressed first. When one lesion is significantly worse than the other and both are asymptomatic, the lesion of greater severity is addressed first and the second later as a staged procedure. Vocal cord paralysis following the first procedure should be ruled out by otolaryngologic examination prior to performing the second procedure. (See 'Otolaryngologic examination' below.)

Carotid endarterectomy prior to other procedures — Carotid intervention prior to other high-risk surgical procedures in patients with carotid artery stenosis is rarely needed, and a decision to proceed should be individualized depending upon the clinician's best estimate of the risk of perioperative stroke.

Coronary artery bypass surgery — Neurologic complications are second only to heart failure as a cause of morbidity and mortality following cardiac surgery. New stroke or transient ischemic attack occurs in approximately 3 percent of patients following coronary artery bypass grafting. As a result, CEA is often considered in conjunction with coronary artery bypass grafting in patients with significant carotid stenosis. However, there have been no trials examining the use of CEA in patients having coronary artery bypass grafting. In addition, it is not clear if CABG should be combined with CEA or should be staged (ie, performed before or after CEA).

Whether to offer CEA before or after coronary artery bypass grafting is discussed in detail elsewhere. (See "Coronary artery bypass grafting in patients with cerebrovascular disease", section on 'Prophylactic carotid intervention'.)

General surgery — The incidence of stroke appears to be lower following general (nonvascular) surgical procedures than following cardiac surgery, with a reported incidence in patients undergoing general anesthesia of less than 0.5 percent [6-8]. The risk may be slightly higher (1 percent) in asymptomatic patients with a carotid bruit who undergo general surgery [9].

There have been no randomized trials examining CEA in patients with carotid stenosis prior to general surgery. A retrospective review suggests that CEA is probably not warranted in most patients with asymptomatic carotid disease to lower their risk of perioperative stroke as a complication of their anticipated general surgical procedure [10]. This study was a chart review of 284 patients who had undergone nonvascular surgery requiring general anesthesia and had preoperative carotid ultrasound. While a previous history of stroke or transient ischemic attack, a carotid bruit, or both were present in 250 patients, all were considered to have asymptomatic carotid stenosis [11]. Ten of 284 patients (3.5 percent) had perioperative ischemic strokes within 30 days of the index procedure, and 8 of 224 (3.6 percent) with >50 percent carotid stenosis had an ipsilateral perioperative stroke (bilateral lesions were present in three patients). While this stroke risk exceeds that of the general population and of patients with carotid bruits, the increased risk appears to be insufficient to mandate CEA for asymptomatic carotid stenosis in the general surgical population.

Major peripheral vascular procedures — Although there are no trials of CEA prior to abdominal aortic aneurysm repair or other major peripheral vascular procedures, many vascular surgeons support performing CEA in those patients with appropriate indications for CEA, in anticipation of a major vascular procedure that may involve significant hemodynamic fluctuations.

Endarterectomy in patients with intracranial aneurysm — Ipsilateral intracranial aneurysms that are distal to a cervical internal carotid artery stenosis may be susceptible to sudden hemodynamic changes associated with CEA leading to aneurysm rupture [12]. On the other hand, surgical clipping of an aneurysm distal to a severe internal carotid stenosis may increase the risk of ischemic stroke.

Unfortunately, data are too sparse to allow firm conclusions as to which problem should be treated first. However, caution is advised if CEA is performed in this setting, especially if the ipsilateral aneurysm is ≥7 mm in diameter or if there is a history of subarachnoid hemorrhage from another aneurysm. (See "Unruptured intracranial aneurysms".)

CONTRAINDICATIONS — The only absolute contraindication to CEA is asymptomatic complete carotid occlusion. When an internal carotid occlusion occurs, thrombus propagates distally and intracranially to at least the first branch of the internal carotid artery, which is the ophthalmic artery. This precludes achieving an endpoint for a CEA performed at the carotid bifurcation in the neck.

Whether it is appropriate to perform carotid revascularization for acute symptomatic carotid occlusion is discussed elsewhere. (See "Management of symptomatic carotid atherosclerotic disease".)

Relative contraindications — The following conditions may increase the risk of local or systemic complications and may support the use of alternative treatments such as medical management and/or carotid angioplasty and stenting [13]:

●History of prior neck irradiation resulting in "woody fibrosis" of the skin and subcutaneous tissues

●Presence of tracheostomy

●Prior radical neck dissection with or without radiation

●Contralateral vocal cord paralysis from prior endarterectomy

●Atypical lesion location, either high or low, that is surgically inaccessible

●Severe recurrent carotid stenosis

●Unacceptably high medical risk (eg, unstable cardiac status) (see 'Risk factors for poor outcome' below)

Patients with these conditions may be candidates for carotid artery stenting. (See "Overview of carotid artery stenting".)

PREOPERATIVE EVALUATION — A thorough vascular history and physical examination are essential components of the evaluation of a patient being considered for CEA. A search can be made for evidence of atherosclerotic disease elsewhere, including abdominal aortic aneurysm and peripheral artery disease. The cost effectiveness and medical benefit of screening under such circumstances is unknown. (See "Screening for abdominal aortic aneurysm" and "Noninvasive diagnosis of upper and lower extremity arterial disease" and "Atrial fibrillation in patients undergoing noncardiac surgery".)

Risk factors for poor outcome — Identification of risk factors for morbidity and mortality associated with CEA is important to avoid surgery in patients who may face an unacceptably high risk for endarterectomy. Advances in perioperative management have led at least some surgeons to conclude that among patients with appropriate indications for CEA, the proportion of patients with an unacceptable surgical risk is extremely small and continues to shrink [14-17]. In one large database study, the investigators noted that morbidity and mortality had declined by 36 percent during the last five years of the study compared with the previous five years [18]. Modifications in surgical practice, refinement of anesthetic techniques and alternatives, refinements in the use of vasoactive medications in the perioperative period, and the declining use of routine preoperative contrast angiography (risk for acute kidney injury) may be responsible for the observed reduction in perioperative complication rates [18]. For patients at high risk for general anesthesia, regional anesthesia is an alternative that has equally good perioperative outcomes [19]. (See 'Anesthesia' below.)

The following characteristics have each been associated with an increased risk of poor outcome (eg, stroke, myocardial infarction, death) at 30 days after CEA in some [20-40], but not all [13,15,16,18,41-48], studies.

●Older age (>70 years in one and ≥80 years in other studies)

●Severe heart disease

●Severe pulmonary dysfunction

●Renal insufficiency or failure

●Stroke as the indication for endarterectomy

●Anatomic issues, including limited surgical access, prior cervical irradiation, prior ipsilateral CEA, and contralateral carotid occlusion (see 'Relative contraindications' above)

Among patients already selected to undergo CEA, there is no convincing evidence that female gender is a significant risk factor for adverse outcomes [49-53]. However, a large database review that included all carotid interventions from New York performed between 2000 and 2009 (27,439 women and 36,295 men) found a higher rate of stroke and acute myocardial infarction for asymptomatic women undergoing carotid intervention compared with propensity score matched men [54].

Two large database reviews support the above risk factors [28,33]. The later and larger of these included 3845 patients from the 2012 CEA-targeted American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) database undergoing CEA for asymptomatic disease in 58.1 percent, and symptomatic disease in 41.9 percent [33]. The overall 30 day postoperative stroke/death rate was 3.0 percent (asymptomatic: 1.9 percent; symptomatic: 4.6 percent). Two factors in asymptomatic patients (contralateral 80 to 99 percent internal carotid artery stenosis, American Society of Anesthesiologists [ASA] Physical Status Classification 4 or 5), and four factors in symptomatic patients (contralateral 80 to 99 percent internal carotid artery stenosis, preoperative stroke, emergency procedure, physiologic high-risk characteristic [age >80 years, renal failure, severe chronic lung disease, and requirement for aortocoronary bypass or cardiac valve surgery ≤30 days]) were independently associated with an increased incidence of postoperative (30 day) stroke/death. These factors were noted to be generally related to patient comorbidities and specific characteristics of their carotid disease, rather than technical features of the CEA procedure. Factors associated with nonstroke 30 day postoperative major morbidity included dependent functional health status, operative time ≥150 minutes, age ≥80 years, ASA Physical Status Classification 4 or 5, bleeding disorder, anatomic high-risk factor, insulin-dependent diabetes mellitus, and preoperative beta blocker use.

Although the specific patient factors that increase perioperative risk following CEA are debated, patients deemed to be at high risk have worse long-term outcomes following CEA [13,24,55]. In a retrospective review of 323 patients with high anatomic and pathophysiologic risk compared with 453 patients with normal risk, no significant differences were found for perioperative outcomes [13]. However, two-year survival was worse in high-risk patients.

Medical risk assessment — Cardiac evaluation should be considered selectively since patients undergoing CEA are most likely to have morbidity related to coronary heart disease. This evaluation may be performed with exercise stress testing, dobutamine echocardiography, dipyridamole imaging, or, when warranted, coronary catheterization [56,57]. However, there is no evidence that immediate cardiac intervention alone reduces perioperative procedural risk of stroke or death for CEA. (See "Evaluation of cardiac risk prior to noncardiac surgery", section on 'Further cardiac testing'.)

Preoperative chest radiography is generally not warranted for most patients undergoing elective surgery. However, a chest radiograph for most patients prior to CEA may be justified due to the association of carotid atherosclerosis with smoking and coronary heart disease [58]. (See "Preoperative medical evaluation of the healthy adult patient", section on 'Chest radiographs' and "Overview of established risk factors for cardiovascular disease".)

Preoperative imaging — Patients suspected of having carotid atherosclerosis are typically evaluated with carotid duplex ultrasound as the initial test to assess the severity and extent of carotid stenosis. Other useful noninvasive methods to assess the degree of stenosis of the internal carotid artery include computed tomography angiography, magnetic resonance angiography, and contrast-enhanced magnetic resonance angiography. The utility of these noninvasive methods and cerebral angiography in the initial evaluation of carotid stenosis is discussed in detail separately. (See "Evaluation of carotid artery stenosis".)

In patients with a hemodynamically significant atherosclerotic lesion identified on duplex ultrasound, it remains controversial if further imaging is needed prior to endarterectomy in asymptomatic patients to verify the degree of stenosis or further evaluate arterial anatomy.

Carotid duplex — Prior to performing CEA in asymptomatic patients, we obtain a duplex ultrasound within one to two weeks of elective CEA to be certain that the carotid artery has not occluded, which contraindicates CEA.

Some surgeons may feel the sensitivity of carotid duplex at their institution is not sufficient to reliably determine the degree of internal carotid artery stenosis or to rule out occlusion [59,60]. In support of this point of view is a lack of uniformly applied, prospectively validated criteria in some settings for quantifying the degree of internal carotid artery stenosis with duplex ultrasound. However, there are disadvantages, risks, and costs associated with other imaging modalities including catheter-based angiography; magnetic resonance angiography, which tends to overestimate the degree of stenosis; and computed tomographic angiography, which may underestimate the degree of stenosis [61-63]. (See "Evaluation of carotid artery stenosis".)

Experts in carotid ultrasound developed consensus-based recommendations for using duplex-derived velocity and imaging parameters to quantify internal carotid artery stenosis with duplex ultrasound [64]. These state that the utility of the recommendations should be verified in individual vascular laboratories, and the suggested parameters should not replace duplex parameters that are locally documented to provide accurate assessment of carotid stenosis. As such, it may be reasonable for the surgeon who has access to a certified vascular laboratory with ongoing quality assurance programs and staffed by registered vascular technologists to use duplex ultrasound as a sole imaging modality of the cervical internal carotid artery prior to performing CEA.

Brain imaging — In the symptomatic patient, the preoperative evaluation should also include computed tomography or magnetic resonance imaging of the brain to assess the degree of cerebral infarction, if any, and to exclude other disorders that might be responsible for symptoms (eg, subdural hematoma, tumor).

The added risk and costs of catheter-based arteriography probably outweigh the benefit of obtaining more anatomic detail. The incidence of stroke associated with routine arteriography was 1.6 percent in the Asymptomatic Carotid Atherosclerosis Study (ACAS) , although this risk was lower than in other reports [65]. However, arteriography is the gold standard for evaluating intracranial atherosclerotic disease, which is present to some degree in many patients with stenosis of the extracranial internal carotid artery [66-68].

In an analysis of a subset of patients from North American Symptomatic Carotid Endarterectomy Trial (NASCET), the relative risk of stroke associated with intracranial atherosclerotic disease in medically treated patients was 1.3 for extracranial stenosis <50 percent and 1.8 for extracranial stenosis 85 to 99 percent [68]. CEA reduced this risk, suggesting that detection of intracranial atherosclerotic disease, particularly in those with moderate extracranial carotid stenosis, may help stratify patients into a group that is more likely to benefit from CEA. Of the available noninvasive tests (ie, transcranial Doppler, computed tomographic angiography, magnetic resonance angiography), CTA may be more accurate for identifying intracranial large artery stenosis. (See "Intracranial large artery atherosclerosis: Epidemiology, clinical manifestations, and diagnosis", section on 'Diagnostic evaluation' and "Evaluation of carotid artery stenosis".)

Otolaryngologic examination — Otolaryngologic examination, which may include laryngoscopy, should be performed in patients who have a residual vocal disturbance (tone change, hoarseness) after a prior neck surgery (eg, CEA, thyroid surgery). (See "Hoarseness in adults", section on 'Neurologic dysfunction' and "Complications of carotid endarterectomy", section on 'Nerve injury'.)

PREOPERATIVE PREPARATION

Medication management

Antiplatelet therapy — Antiplatelet therapy with aspirin reduces the risk of stroke of any cause in patients undergoing CEA [69,70]. In addition, lower-dose aspirin (81 to 325 mg daily) is more effective than higher-dose aspirin (650 to 1300 mg daily).

●In a randomized trial involving 232 patients, aspirin (75 mg daily) or placebo treatment was started preoperatively and continued for six months [71]. Patients assigned to aspirin had significantly fewer strokes at one month and six months compared with those assigned to placebo. However, this study was likely underpowered [72].

●The ASA and Carotid Endarterectomy (ACE) trial randomly assigned 2849 patients scheduled for endarterectomy to aspirin at doses of 81, 325, 650, or 1300 mg daily [73]. Aspirin was started before surgery and continued for three months. At three-month follow-up, the primary endpoint (stroke, myocardial infarction, vascular death) was significantly reduced in the lower-dose (81 or 325 mg daily) aspirin group compared with the higher-dose group (6.2 versus 8.4 percent).

Consensus guidelines from the American Academy of Neurology (AAN) and the American College of Chest Physicians (ACCP) recommend aspirin for symptomatic and asymptomatic patients undergoing CEA [72,74]. We recommend starting aspirin (81 to 325 mg daily) prior to CEA and continuing indefinitely in the absence of contraindications. Although other agents are available, aspirin is the best studied antiplatelet agent following CEA, and aspirin alone is generally deemed adequate for postoperative management given that the carotid plaque has been removed. However, for patients who are allergic or sensitive to aspirin, clopidogrel can be used as an alternative agent. For those patients with atherosclerotic plaque elsewhere (eg, lower extremity), other agents or combinations may be favored for long-term secondary prevention of cardiovascular events.

Any decision to use another agent or to add additional antithrombotic agents needs to be individualized based upon the indications for dual antiplatelet therapy or triple antithrombotic therapy [75-77]. It may be reasonable to allow patients with chronically administered dual antiplatelet therapy for other indications to continue these throughout the perioperative period. In one trial of 102 patients undergoing CEA, no significant difference in perioperative bleeding was found in patients taking dipyridamole/aspirin (n = 39), dipyridamole/aspirin plus dextran (n = 30), or dipyridamole/aspirin plus clopidogrel (n = 33) [77]. However, in a database review from the Vascular Quality initiative, among 28,683 CEAs, 7059 (25 percent) were on dual antiplatelet therapy (aspirin plus clopidogrel), and the use of aspirin plus clopidogrel was associated with a significant increase in the risk for bleeding and reoperation after CEA, but the risk for perioperative neurologic events was significantly reduced [78]. (See "Prevention of cardiovascular disease events in those with established disease (secondary prevention) or at very high risk" and "Long-term antithrombotic therapy for the secondary prevention of ischemic stroke" and "Aspirin for the secondary prevention of atherosclerotic cardiovascular disease".)

Long-term anticoagulation — A decision to stop versus bridge long-term oral anticoagulation prior to CEA is individualized and made together with the patient's cardiologist or medical physician [79]. (See "Perioperative management of patients receiving anticoagulants" and "Coronary artery disease patients requiring combined anticoagulant and antiplatelet therapy".)

Regardless of whether oral anticoagulation is continued or temporarily discontinued (with or without bridging anticoagulation), antiplatelet therapy (ie, aspirin or clopidogrel) is initiated prior to CEA in the manner discussed above. (See 'Antiplatelet therapy' above.)

Following CEA, if oral anticoagulation was temporarily discontinued, it is resumed and aspirin or clopidogrel initiated preoperatively is continued. Any new ischemic or bleeding episodes (or change in bleeding risk) should lead to a reevaluation of antithrombotic therapy.

Statins — The use of statins in symptomatic patients undergoing CEA may be associated with improved outcomes. In a retrospective observational study of 3360 CEAs, statin use was associated with reduced in-hospital mortality and combined in-hospital ischemic stroke or death (adjusted odds ratio 0.25, 95% CI 0.07-0.90 and 0.55, 95% CI 0.32-0.95, respectively), but in-hospital cardiac outcomes were not significantly improved [80]. A later, large database study reported similar results [81]. In contrast, statin use by patients with asymptomatic carotid stenosis was not associated with significantly different outcomes.

Similar results were reported in another retrospective study involving 1566 patients with symptomatic and asymptomatic disease who received statins for at least one week before CEA [82]. These findings require confirmation in randomized clinical trials.

Evidence is also emerging that statins may be of benefit in the perioperative period, and that this benefit might be lost if statins are discontinued. This issue is discussed elsewhere. (See "Perioperative medication management", section on 'Non-statin hypolipidemic agents'.)

Sedative-analgesic medications — Certain sedative-analgesic medications may be warranted to relieve preoperative anxiety. When an anxiolytic is chosen, a short-acting agent should be used, and it should be administered only after the patient's neurologic examination has been documented. (See "Anesthesia for carotid endarterectomy and carotid stenting".)

Prophylactic antibiotics — We recommend administration of antibiotics prior to CEA to control surgical site infection due to the frequent use of prosthetic material (table 1) [83]. (See "Antimicrobial prophylaxis for prevention of surgical site infection in adults", section on 'Vascular surgery'.)

SURGICAL ANATOMY AND PHYSIOLOGY

Carotid artery — The left common carotid artery originates from the aortic arch, whereas the right common carotid artery originates from the innominate artery (figure 1). The common carotid artery divides into the internal carotid artery and external carotid artery typically at the level of the superior border of the thyroid cartilage corresponding to the C3/C4 disc space. The vagus nerve is located posteriorly to the common carotid artery in most individuals, although it may be located anteriorly in 5 to 10 percent of cases.

External carotid artery — The external carotid artery has multiple branches that supply the face and scalp and provide collateral circulation to the brain (figure 2). These branches include (caudal to cranial) the superior thyroid, lingual, facial, ascending pharyngeal, occipital, posterior auricular, maxillary, and superficial temporal arteries. The ascending pharyngeal artery arises very near the bifurcation of the carotid artery. In one anatomic study, the ascending pharyngeal artery originated from the external carotid artery in 80 percent of specimens (56 percent medially, 44 percent posteriorly) [84]. In the other 20 percent, the ascending pharyngeal artery originated from the internal carotid artery (5 percent), carotid bifurcation (5 percent), occipital artery (5 percent), and a trunk common to the lingual and facial arteries (5 percent).

Internal carotid artery — The internal carotid artery normally has no branches in the neck (figure 3). The cervical segment of the internal carotid extends from the carotid bifurcation until it enters the carotid canal anterior to the jugular foramen. The internal carotid artery runs cranially within the carotid sheath and lies posterior and lateral to the external carotid artery beneath the medial border of the sternocleidomastoid muscle. In its distal (cranial) course, it passes beneath the hypoglossal nerve, the digastric muscle, the stylohyoid muscle, the occipital artery, and the posterior auricular artery. More cranially, the styloglossus and stylopharyngeus muscles, the tip of the styloid process and the stylohyoid ligament, the glossopharyngeal nerve, and the pharyngeal branch of the vagus nerve separate the internal from the external carotid artery.

Location and influence of the carotid baroreceptor — Baroreceptors are stretch-sensitive mechanoreceptors that respond to alterations in blood pressure. The carotid sinus baroreceptors are located within the adventitia of the origin of the internal carotid artery and are innervated by the sinus nerve of Hering, which is a branch of glossopharyngeal nerve. In response to low blood pressure, the nerve fibers decrease their firing rates, stimulating the sympathetic nervous system and inhibiting the parasympathetic nervous system via a centrally acting mechanism. Carotid sinus reactivity may be altered in patients with carotid atherosclerosis. (See "Pathophysiology of symptoms from carotid atherosclerosis", section on 'Impaired vasoreactivity'.)

Patients display varying degrees of heart rate or blood pressure alterations during manipulation of the carotid bifurcation, carotid clamping, or postoperatively following CEA [85]. Endarterectomy, removal of atheromatous debris, and reconstruction of the carotid artery may increase tension on the carotid sinus baroreceptor, increasing its activity [86]. The opposite is also possible if damage to the carotid sinus or sinus nerve occurs. As an example, eversion endarterectomy requires division of the carotid artery, and as a result, the longitudinal fibers of the carotid sinus nerve are transected. A study that measured baroreceptor sensitivity following CEA found increased sensitivity with conventional CEA and decreased sensitivity with an eversion technique [87]. Correspondingly, postoperative blood pressures were significantly increased for eversion compared with conventional CEA (systolic: 127, diastolic: 64, mean: 86; versus systolic: 111, diastolic: 55, mean: 75). Compensation over time occurs due to intact baroreceptor mechanisms from the contralateral side and aortic arch. (See 'Conventional versus eversion endarterectomy' below.)

ANESTHESIA — Carotid endarterectomy can be performed using local/regional anesthesia or general anesthesia. Ideally, surgical and anaesthetic teams should be competent in both techniques because a patient might prefer, or there might be a medical reason to choose, one anesthetic technique rather than another [88].

In an analysis of 26,070 cases in the American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) database, general anesthesia was used in 84.6 percent and regional anesthesia was used in 15.4 percent of cases [89]. In another study looking at over 75,000 cases, 8.9 percent were performed under local/regional anesthesia. CEA performed under general anesthesia was associated with twice the odds of in-hospital myocardial infarctions, four times the odds of acute congestive heart failure, 1.5 times the odds of hemodynamic instability, and 1.8 times the odds of staying in the hospital for >1 day. However, the authors noted that the overall risk of adverse cardiac events after CEA was overall low, which made the differences clinically irrelevant [90]. Local/regional anesthesia may be more beneficial for some patients but can be uncomfortable for the patient and may necessitate urgent conversion to general anesthesia or urgent shunt placement. (See "Anesthesia for carotid endarterectomy and carotid stenting", section on 'General versus local/regional anesthesia'.)

Anesthetic choice — The use of general anesthesia for CEA or performing awake carotid surgery with local anesthesia (with or without cervical block) is generally determined by surgeon preference and patient characteristics and preference. The available evidence suggests that the choice of anesthetic technique has no significant impact on clinically important outcomes after CEA [88,91-93]. (See "Anesthesia for carotid endarterectomy and carotid stenting", section on 'General versus local/regional anesthesia'.)

Assessing brain perfusion — Although 80 to 85 percent of patients tolerate clamping of the carotid artery without consequence, the collateral circulation via the circle of Willis should be assessed in all patients who do not undergo mandatory shunting. (See 'Preoperative imaging' above and 'Carotid shunting' below.)

During local/regional anesthesia in cooperative patients, clinical assessments are made during the procedure by monitoring mental status, speech, and extremity function. Agitation, slurred speech, disorientation, and extremity weakness are indications for shunt placement. During general anesthesia, assessment of cerebral perfusion to determine which patients should receive a shunt can be accomplished with a variety of methods (eg, measurement of carotid stump pressure, transcranial Doppler, somatosensory evoked potentials, jugular venous oxygen saturation). The most commonly used methods are discussed in detail elsewhere. The author prefers electroencephalography monitoring. (See "Anesthesia for carotid endarterectomy and carotid stenting", section on 'Neuromonitoring' and 'Carotid shunting' below.)

SURGICAL TECHNIQUE

Endarterectomy procedure

General conduct of operation — CEA is performed through a neck incision, either bordering the sternocleidomastoid muscle, or with a transverse incision in a skin crease at the level of carotid bulb. For the latter incision, preoperative imaging with ultrasound will guide the surgeon to the optimal placement of the incision. No significant differences between these approaches have been identified in terms of stroke, wound complications, or nerve complications [94].

The underlying platysma muscle and subcutaneous tissues are divided, the carotid sheath exposed, and the internal carotid artery is carefully identified and dissected. The extent of exposure of the artery is dependent upon the distribution of disease determined by intraoperative findings. Typically, dissection is needed from the common carotid artery to a point distal to the bifurcation of the internal carotid artery and external carotid artery that is beyond palpable internal carotid artery plaque to allow for clamping of normal soft artery.

During carotid dissection, the patient is systemically anticoagulated (heparin given as bolus, or using an alternative agent, as indicated). Monitoring the activated clotting time is not usually needed, owing to the short duration of carotid clamping, which is typically less than an hour. (See "Anesthesia for carotid endarterectomy and carotid stenting", section on 'Anticoagulation management'.)

Carotid stump pressures can be obtained after clamping the proximal common and external carotid arteries. The internal, common, and external arteries are then clamped sequentially; the internal carotid artery is always clamped first to prevent embolization. A needle attached to a transducer is introduced into the common carotid artery. The clamp on the internal carotid artery is released and a waveform is obtained. Mean pressures greater than 30 to 50 mmHg imply adequate collateralization via the circle of Willis down the ipsilateral carotid artery. Lower stump pressures are an indication for shunt placement, and higher pressures are associated with stroke rates <0.5 percent [95]. Critics of this technique caution that pressures are only obtained after initial clamping and, therefore, represent a "snapshot" in time. In addition, the criteria above should be used with caution in patients who have suffered prior ipsilateral strokes (potential vulnerable penumbra surrounding the prior infarct) since there is a poor correlation between adequate perfusion pressures and outcomes in this setting. The accuracy of the pressure in the face of a preocclusive (string) lesion may also be questionable. (See 'Assessing brain perfusion' above.)

After measurement of the stump pressure, the clamp is placed back on the distal internal carotid artery, and the transducer needle is removed. Manipulation of the carotid bulb during CEA not infrequently results in hemodynamic instability intraoperatively and in the early postoperative period [96]. Adequate cerebral perfusion pressure (ie, systolic blood pressure) should be maintained during periods of hemodynamic instability to avoid low cerebral blood flow and cerebral ischemia.

A longitudinal arteriotomy is performed below the level of the bifurcation and extended proximally and distally. If shunting is required, the shunt is placed after the vessel is opened and prior to the endarterectomy. For patients who are undergoing general anesthesia, some surgeons routinely place a carotid shunt while others use cerebral perfusion monitoring to guide the need for selective shunt placement. For these patients and those undergoing awake CEA using local anesthesia (with or without cervical block), the endarterectomy is often completed prior to the need to place a shunt, as indicated by brain monitoring. (See 'Carotid shunting' below and 'Assessing brain perfusion' above.)

The carotid plaque, which is consistently found at the carotid bifurcation and the origin of the internal carotid artery, is then freed and removed through a dissection plane developed in the layers of the deep media. Great care is taken to create a smoothly tapered transition between the endarterectomized portion of the artery and its normal distal extent. This maneuver avoids intimal flaps that might lead to arterial dissection after flow is reestablished. Some surgeons will place "tacking sutures" at the distal end of the endarterectomy to further guard against possible dissection of the distal internal carotid artery following restoration of blood flow. A variation of the procedure removes the plaque after transecting the internal carotid near its origin. (See 'Conventional versus eversion endarterectomy' below.)

After meticulous inspection of the endarterectomized surface to remove any residual plaque or debris, attention is directed at repair. Some surgeons choose to repair primarily, while others patch the artery with saphenous vein or prosthetic material such as polyester (eg, Dacron), polytetrafluoroethylene (eg, Gore-Tex), or bovine pericardium. There is evidence that routine patch use lowers the risk of perioperative carotid thrombosis, stroke, and late restenosis of the endarterectomy site. (See 'Patch angioplasty versus primary closure' below.)

Just prior to completion of the arterial closure, the carotid clamps are sequentially briefly released and re-clamped to back bleed (external carotid artery, internal carotid artery) and forward flush (common carotid artery) the vessel, which is then irrigated (eg, heparinized saline) and suctioned of any residual debris. After the suture line is completed, flow is restored first to the external carotid artery, then to the internal carotid artery to avoid any distal embolization to the cerebral hemisphere. A topical hemostatic agent may be used over the suture line to slow any oozing of blood.

At the completion of the procedure, we suggest reversal of heparin with protamine. The only randomized trial comparing protamine with no protamine found significantly lower rates of wound drainage but cautioned that protamine might increase the risk for thrombotic complications [97]. In a retrospective analysis of 4587 patients in a regional registry, reversal of heparin with protamine was associated with a lower incidence of serious bleeding requiring reoperation (0.64 versus 1.7 percent) compared with no reversal, without increasing the risk of myocardial infarction, stroke, or death [98]. A later systematic review that included the randomized trial, the registry study, and 10 other observational studies similarly found no significant differences for stroke (nine studies), myocardial infarction (three studies), or mortality (seven studies) for those who received protamine compared with those who did not; however, protamine use significantly decreased the risk of major bleeding complications requiring reoperation (relative risk [RR] 0.57; 95% CI 0.39-0.84; 10 studies) [99]. Dosing of heparin (fixed dosing, per body weight), dosing of protamine, and use of monitoring via activated clotting time varied across the studies and could not be adequately evaluated. A subgroup analysis suggested that stroke risk may be higher for primary carotid closure compared with patch closure when using protamine, but the overall number of events was small, limiting the ability to draw a firm conclusion.

Although a small Jackson-Pratt drain can be placed, drains are generally not required and have not been shown to definitively reduce the rates of significant postoperative incisional hematomas. The platysma and skin are closed and the wound dressed.

A completion study to assess the integrity of the repair can be performed intraoperatively using Doppler evaluation, duplex ultrasound, contrast arteriogram, depending upon resources and operator preference [100-112]. A retrospective review that categorized surgeons as rarely, selectively, or routinely using completion imaging found no significant differences in perioperative stroke or death after adjustment for patient characteristics [104]. A small but significant reduction in restenosis (>70 percent) was found for surgeons who performed completion imaging.

High access — More distal (cranial) access may be needed. As the internal carotid artery is dissected, the hypoglossal nerve will be seen to cross anteriorly. The nerve is isolated and gently retracted.

The ansa hypoglossus (ansa cervicalis) nerve, which innervates the strap muscles of the neck, is typically seen coursing along the carotid sheath. The ansa can be divided without clinically significant consequence when dissection needs to be carried more cranially. The posterior belly of the digastric muscle can also be divided. Subluxation of the jaw facilitated by nasotracheal intubation, or mandibular osteotomies, while frequently discussed, are rarely warranted.

Conventional versus eversion endarterectomy — Eversion endarterectomy is a variant of CEA. The internal carotid artery is transected horizontally at its origin at the carotid bulb and then the artery is everted, or turned inside out, which creates an exposure not seen with vertical arteriotomy. A modification of the technique that uses a linear incision over the common carotid artery and proximal internal carotid artery has been described [113]. Eversion endarterectomy is particularly appealing in small arteries and in patients with significant carotid redundancy as a means to eliminate carotid kinks and coils. However, in our opinion, the bulk of the evidence does not favor one technique over the other.

The largest and best designed trial comparing eversion endarterectomy with conventional endarterectomy (EVEREST trial) was a multicenter trial that included 1342 patients [114]. No significant differences were found for the primary endpoints (perioperative stroke and death, carotid occlusion) or secondary endpoints (any stroke, ipsilateral stroke, transient ischemic attack, cranial nerve injury, neck hematoma, myocardial infarction). For eversion CEA compared with conventional CEA, the odds ratio for a combined endpoint of perioperative major stroke or death was 1.0 (95% CI 0.4-2.9), and for any perioperative stroke, 1.2 (95% CI 0.5-2.7). Compared with CEA performed without a patch, eversion CEA and conventional patched CEA each had a lower risk of carotid restenosis (hazard ratio [HR] 0.3, 95% CI 0.2-0.6, and HR 0.2, 95% CI 0.07-0.6, respectively). A meta-analysis that included the EVEREST trial and five other smaller trials [114-120] identified a trend toward a reduced risk of perioperative (30 day) stroke for eversion CEA compared with conventional CEA (odds ratio [OR] 0.56, 95% CI 0.33-0.96) [121].

Randomized trials and other observational studies that have evaluated conventional versus eversion CEA have included patients with asymptomatic and symptomatic disease [114-122]. A post hoc analysis of data from the Stent-Protected Angioplasty versus Carotid Endarterectomy in Symptomatic Patients (SPACE-1) trial found no overall difference between the techniques; however, perioperative outcomes were better for conventional CEA, while later outcomes favored eversion CEA [123]. Ipsilateral stroke or death ≤30 days was significantly reduced for conventional versus eversion CEA (9 versus 3 percent), but the risk of ipsilateral stroke >30 days was significantly lower for eversion compared with conventional CEA (3 versus 0 percent). Interestingly, eversion CEA was not found to have a significantly lower incidence of restenosis in contrast to other studies [121,124].

Proponents of eversion CEA feel that once the technique has been mastered, it may be easier to perform than conventional CEA. Although this may be so, advocates of conventional CEA point out that shunt insertion during eversion CEA can be more difficult since the plaque must be completely removed before the shunt can be inserted. In addition, eversion CEA is less commonly introduced during vascular surgery training, and, for those who adopt it later, the technique may be associated with a learning curve. A retrospective review at an academic medical center compared the outcomes of the first 100 patients on whom they performed eversion endarterectomy with 100 patients who underwent conventional endarterectomy [125]. The rate of perioperative neurologic deficits and deaths were not significantly different. One case of amaurosis occurred after eversion CEA, and one case each of transient cerebral ischemia and retinal infarction after conventional CEA; one cardiac death occurred with each. No significant differences were seen in the rate of critical (>80 percent) residual or recurrent stenosis, late stroke, or late carotid occlusion at 36 months follow-up. However, eversion endarterectomy had a higher rate of >50 percent recurrent stenosis (38 versus 6 percent) compared with conventional CEA in spite of similar residual stenosis rates. The significance of this late mild-to-moderate stenosis is unknown. A systematic review comparing techniques found a higher risk of early postoperative hypertension for eversion endarterectomy; conventional techniques were more often associated with hypotension [126].

Patch angioplasty versus primary closure — As noted above, some surgeons choose to repair to the carotid artery primarily, while others patch the artery with saphenous vein or material (eg, polytetrafluoroethylene, Dacron, bovine pericardium) [127-132]. We recommend patch closure for all patients undergoing CEA (noneversion technique).

The trials that have been performed suggest two benefits from use of a patch: a marked reduction in the frequency of ≥50 percent restenosis and a lower rate of ipsilateral stroke [133,134]. A systematic review of patch angioplasty versus primary closure during CEA identified 10 eligible randomized controlled trials involving 1967 patients undergoing 2157 operations [134]. Many of the trials were limited by significant methodological flaws; most were small, and none could be analyzed on a true intention-to-treat basis because of losses to follow-up. The use of a patch is associated with:

●Reduction in the risk of ipsilateral stroke in the perioperative period (OR 0.31, 95% CI 0.1-0.63 and long-term OR 0.32, 95% CI 0.16-0.63).

●A reduced risk of perioperative arterial occlusion (OR 0.18, 95% CI 0.08-0.41).

●Decreased restenosis during long-term follow-up in eight trials (OR 0.24, 95% CI 0.17-0.34). These results are more certain than those of the previous review since the number of operations and events have increased. However, the sample sizes are still relatively small, data were not available from all trials, and there was significant loss to follow-up.

●No significant correlation was found between use of patch angioplasty and the risk of either perioperative or long-term all-cause death rates.

A separate systematic review identified 13 trials involving 2083 operations [132]. Seven trials compared vein patch closure with polytetrafluoroethylene patch closure, and six trials compared Dacron patches with other synthetic materials. No significant differences were found comparing synthetic patches versus vein patches for stroke, stroke or death, arterial occlusion, arterial rupture, nerve palsy, wound infection, or recurrent arterial stenosis during perioperative or one-year follow-up. The review identified one high-quality trial that compared Dacron with polytetrafluoroethylene patches and found that Dacron patches were associated with an increased risk for perioperative stroke and an increased risk for both perioperative and late recurrent carotid stenosis [129,130].

Using a synthetic patch was found to decrease the risk of pseudoaneurysm relative to using a vein patch (OR 0.09, 95% CI 0.02-0.49). However, the studies that examined pseudoaneurysm outcomes were older [135-137], using saphenous vein, jugular vein, or other vein sites; the technical aspects of vein handling were not included. In one of these studies, the incidence of pseudoaneurysm was 17 percent using jugular vein, 9 percent using saphenous vein or polytetrafluoroethylene, and 5 percent with primary closure [135]. The use of vein during initial CEA has declined, but when vein is needed (eg, graft infection, redo carotid surgery), we prefer to use proximal saphenous vein harvested from the groin. A later trial comparing polytetrafluoroethylene (eg, Acuseal) with bovine pericardium also found no significant differences between these materials for ipsilateral stroke, recurrent carotid stenosis, or other perioperative complications (eg, neck hematoma); mean hemostasis time was slightly lower for the polytetrafluoroethylene patch.

Very few arterial complications, including hemorrhage, infection, cranial nerve palsies, and pseudoaneurysm formation, have been evaluated with patch compared with primary closure, but the available data suggest no significant differences [138].

Carotid shunting — If the patient demonstrates evidence of cerebral ischemia by any neuromonitoring technique, carotid shunting should be performed expeditiously. A temporary shunt is placed beyond the proximal and distal extent of the arteriotomy from the common to the internal carotid artery. Blood flows through the shunt, providing continuous cerebral perfusion during the procedure. Neurologic reassessment is performed again.

In awake patients, shunt placement is indicated for those who develop agitation, slurred speech, disorientation, or extremity weakness, or the presence of theta and delta waves or disorganized rhythms on electroencephalography monitoring in the patient who is asleep [139]. Although carotid stump pressures were used to determine the need for carotid shunting during general anesthesia in the past, electroencephalography (raw or processed) is more commonly used to monitor brain perfusion. A neuromonitoring team assesses the electroencephalography tracings for cerebral ischemia indicating the need for shunting (eg, presence of theta and delta waves or disorganized rhythms). (See 'Assessing brain perfusion' above.)

Routine versus selective shunting — Studies targeted at defining the best approach (mandatory shunting, selective shunting) have been equivocal with respect to demonstrating any difference in important clinical outcomes. Given that there is no consensus, neurologic monitoring with selective shunting versus routine shunting has been largely a matter of surgeon preference [140-144]. When a shunt is used, the distal end is placed first into the internal carotid artery and the shunt back-bled to wash out any debris or air bubbles within the shunt prior to placing it into the common carotid artery and restoring cerebral perfusion. To minimize trapping debris within the shunt, it is mandatory to place the shunt in relatively disease-free segments of the internal and common carotid arteries.

Surgeons who routinely shunt feel that shunt complications are less likely to occur if shunting is routinely performed. The advantages of routine shunting may include:

●Familiarity of the surgeon and surgical team with the technique – Data from the Vascular Study Group of New England (VSGNE) database found that surgeons who routinely shunted had lower stroke rates during CEA in patients with contralateral carotid occlusion compared with those who selectively shunted [145]. The higher rate of stroke amongst practitioners who selectively shunted may be attributable to a lack of familiarity with the procedure. Other groups have also reported a higher rate of shunting in patients with contralateral carotid occlusion [146,147].

●Cerebral flow is assured with a properly placed shunt without need for neurological monitoring (electroencephalography, stump pressure, awake neurologic examination).

Although some surgeons prefer to use carotid shunts routinely to avoid the need for intraoperative neuromonitoring, it should be recognized that shunting is unnecessary in approximately 90 percent of patients. Proponents of carotid shunting argue that selective shunting exposes patients to the risks of shunting that may include the following:

●Formation of an intimal flap during shunt insertion, resulting in arterial dissection

●Dislodgement of plaque emboli during vessel manipulation

●Air embolism due to bubbles in the shunt

With awake CEA, a carotid shunt is needed in <5 percent of patients. A meta-analysis of five trials found significantly less shunt use for local anesthesia compared with general anesthesia (OR 0.27, 95% CI 0.23-0.31) [91]. However, there were no significant differences in the rates of stroke or death.

A review of the literature that included 4046 patients from observational studies and randomized trials reported the following mean perioperative stroke rates for CEAs using various shunting schemes [148].

●Routine shunting – 1.4 percent

●Routine nonshunting – 2 percent

●Selective shunting – 1.6 percent

•Regional anesthesia (cervical block, awake CEA) – 1.1 percent

•Electroencephalogram – 1.6 percent

•Stump pressure – 1.6 percent

•Somatosensory evoked potentials – 1.8 percent

•Transcranial Doppler – 4.8 percent

A systematic review that identified three trials involving 686 patients found no significant differences in the rates of all stroke, ipsilateral stroke, or death up to 30 days for patients that were routinely shunting compared with no shunting [140].

Shunt type — There are insufficient data to support one type of carotid shunt over another [144]. Many shunts are available for use (Argyle, Pruitt-Inahara, Brenner, Burbank, Sundt), and each has its advantages and disadvantages. The features (stiff versus flexible, inline Doppler, balloons for occlusion) and use of these shunts can be found on proprietary websites. The selection of a particular shunt is based largely on surgeon experience. Most surgeons become comfortable using one particular shunt.

Several studies have identified factors that may increase the need for a shunt, including older age, female gender, hypertension, contralateral carotid artery occlusion, and history of contralateral carotid artery surgery [148]. Although some surgeons prefer to use carotid shunts routinely to avoid the need for intraoperative neuromonitoring, it should be recognized that shunting is unnecessary in approximately 90 percent of patients.

POSTOPERATIVE CARE — Upon recovering from anesthesia, a neurologic assessment is performed and repeated every hour during recovery. Because blood pressure lability is common in the first 12 to 24 hours postoperatively, it is standard care for CEA patients to be placed in a monitored setting with an arterial line in place. Systolic blood pressure should be maintained between 100 to 150 mmHg in the postoperative period to prevent complications related to hypertension (eg, neck hematoma) or hypotension (eg, cerebral ischemia). (See "Anesthesia for carotid endarterectomy and carotid stenting", section on 'Blood pressure control'.)

Minor headache is common following CEA, but increasing or severe headache in the postoperative period may be an indicator of cerebral hyperperfusion syndrome or intracranial hemorrhage and should be evaluated with a computed tomographic scan. (See "Complications of carotid endarterectomy", section on 'Hyperperfusion syndrome'.)

PERIOPERATIVE MORBIDITY AND MORTALITY — While a number of controlled trials have highlighted the patient population most likely to benefit from CEA, this operation is not without risk [149]. (See "Management of symptomatic carotid atherosclerotic disease", section on 'Patients appropriate for CEA'.)

Perioperative mortality associated with CEA ranges from <0.5 to 4.3 percent and may be higher when this procedure is performed at nontertiary care centers [1,150-152]. Surgeons are encouraged to keep accurate records of their individual stroke rates to ensure that standards are upheld. Low patient volume (<3 CEAs performed every two years) and a greater number of years since licensure of the surgeon are associated with worse outcomes following CEA [153,154].

A retrospective review of the United States Medicare database evaluated outcomes of 454,717 CEA and 27,943 carotid artery stenting patients before and after the 2005 National Coverage Determination to reimburse carotid artery stenting for Medicare beneficiaries [154]. CEA rates declined from 18.1 to 12.7 per 10,000 beneficiaries between 2002 and 2008 (overall rates also declined). Even though patients undergoing CEA in later years were older and had more comorbidities compared with earlier years, perioperative (30 day) mortality declined from 1.4 to 1.17 percent.

In a later systematic review of only large (>1000 participants each) observational cohort studies, the composite risk of procedural stroke/death among over 130,000 patients undergoing CEA decreased from before 2005 compared with from 2005 onward for both symptomatic patients and asymptomatic patients (5.1 versus 2.7 percent and 3.2 versus 1.5 percent, respectively) [155]. By comparison, procedural stroke/death rates for CAS did not change significantly over time (symptomatic: 4.8 percent; asymptomatic: 2.6 percent). For studies that reported stroke alone or death alone, no differences were seen from before 2005 compared with from 2005 onward for either procedure. The authors speculated that a trend toward centralization of CEA in high-volume centers, and specialist support, may have contributed to the decrease in CEA procedural risks.

Complications associated with CEA include perioperative events such as myocardial infarction; stroke; hyperperfusion syndrome; nerve injury; parotitis and bleeding, which can lead to neck hematoma requiring reoperation; and late carotid restenosis. These complications are discussed in detail elsewhere. (See "Complications of carotid endarterectomy".)

FOLLOW-UP CARE — Following CEA, patients are typically discharged within one to three days. The most common delay in discharge is due to difficulties controlling blood pressure. Control of blood pressure prior to performing CEA cannot be overemphasized. We follow up with the patient at one month postoperatively, at which time we also obtain a carotid duplex study. If there are any wound-related issues or other problems, arrangements should be made to see the patient sooner.

Readmission following CEA is relatively high. In a review that included 235,247 patients undergoing carotid intervention, 8.8 percent of the patients undergoing CEA required readmission, which was lower compared with carotid artery stenting [156]. Significant factors that increased the likelihood of readmission included age >80 years (odds ratio [OR] 1.25, 95% CI 1.20-1.30), renal failure (OR 1.6, 95% CI 1.56-1.73), heart failure (OR 1.6, 95% CI 1.57-1.73), and diabetes (OR 1.4, 95% CI 1.27-1.52). A separate review of data from 2005 to 2010 from the National Surgical Quality Improvement Program (NSQIP) found that 33 percent of strokes, 53 percent of deaths, and 32 percent of cardiac events occurred after hospital discharge [157].

Wound care — The postoperative dressing is removed on the first postoperative day. If a drain has been placed, it should be removed as soon as possible in the postoperative period (day 1 or 2) to decrease the potential for wound infection provided there is no significant drainage. Antibiotics are limited to perioperative prophylaxis. (See 'Prophylactic antibiotics' above.)

Duplex surveillance — Repeat duplex ultrasonography should be obtained three to six weeks following CEA to establish a new baseline for future comparison. Duplex surveillance is performed at six months and annually. More frequent intervals may be warranted if a contralateral stenosis is being observed. (See "Complications of carotid endarterectomy", section on 'Carotid restenosis'.)

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Occlusive carotid, aortic, mesenteric, and peripheral atherosclerotic disease".)

INFORMATION FOR PATIENTS — UpToDate offers two types of patient education materials, "The Basics" and "Beyond the Basics." The Basics patient education pieces are written in plain language, at the 5^th to 6^th grade reading level, and they answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials. Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are written at the 10^th to 12^th grade reading level and are best for patients who want in-depth information and are comfortable with some medical jargon.

Here are the patient education articles that are relevant to this topic. We encourage you to print or e-mail these topics to your patients. (You can also locate patient education articles on a variety of subjects by searching on "patient info" and the keyword(s) of interest.)

●Basics topics (see "Patient education: Carotid artery disease (The Basics)")

SUMMARY AND RECOMMENDATIONS

●The effectiveness of carotid endarterectomy (CEA) for moderate-to-severe asymptomatic or symptomatic carotid artery stenosis has been established in large randomized trials. CEA in patients with asymptomatic carotid stenosis prior to cardiac or general surgery has no demonstrated benefit. For patients with indications for bilateral CEA, a staged rather than combined procedure is performed. (See "Management of symptomatic carotid atherosclerotic disease" and "Management of asymptomatic extracranial carotid atherosclerotic disease" and 'Introduction' above and 'Carotid atherosclerotic disease' above.)

●Prior to CEA for asymptomatic carotid stenosis, duplex ultrasound may be sufficient to reliably determine the degree of internal carotid artery stenosis and assess local anatomy when performed in a certified vascular laboratory using validated criteria. If these standards cannot be met, additional imaging to verify the degree of stenosis should be performed. (See 'Carotid duplex' above.)

●Prior to CEA, we recommend starting aspirin (81 to 325 mg daily) and continuing treatment indefinitely (Grade 1B). For patients who are sensitive to aspirin, clopidogrel is an alternative agent. (See 'Antiplatelet therapy' above.)

●For patients with symptomatic carotid stenosis, we suggest initiation of statin therapy prior to CEA (or maintenance in patients already being treated) (Grade 2B). The use of statins in symptomatic patients is associated with reduced morbidity and mortality following CEA. For patients with asymptomatic carotid stenosis undergoing CEA, statin therapy has not shown the same benefit but may be indicated for other medical reasons. (See 'Statins' above.)

●We recommend antibiotic prophylaxis prior to CEA to reduce the risk of surgical site infection due to the frequent use of prosthetic material (Grade 1B). Antibiotics should be discontinued within 24 hours. (See 'Prophylactic antibiotics' above.)

●CEA can be performed using general anesthesia or local anesthesia (with or without cervical block). Statistically significant differences for major endpoints (perioperative stroke, myocardial infarction, and death) have not been consistently shown for differing anesthetic approaches. The choice of anesthesia technique is largely dependent on the preferences of the patient, the anesthesiologist, and the surgeon. (See 'Anesthesia' above.)

●No one technique for plaque removal has been found to be superior over another with respect to the incidence of stroke, death, or other morbidity. As with many surgical techniques, one technique may be preferable to another for specific circumstances, and the choice of technique is largely dependent on the preferences and experience of the surgeon. (See 'Endarterectomy procedure' above and 'Conventional versus eversion endarterectomy' above.)

●Prior to carotid artery clamping, the patient is systemically anticoagulated, typically using heparin. At the completion of the procedure, we suggest reversal of heparin with protamine over no reversal (Grade 2B). (See 'General conduct of operation' above.)

●Following carotid plaque removal, we recommend patch closure of the carotid artery over no patch (noneversion technique) (Grade 1B). With conventional CEA, carotid patch techniques are associated with decreased rates of stroke and carotid restenosis. No one patch material (synthetic, vein, bovine pericardium) has been shown to be superior over another. (See 'Patch angioplasty versus primary closure' above.)

●After the completion of the procedure, the patient's neurologic status and blood pressure are carefully monitored. We keep the systolic blood pressure between 100 and 150 mmHg. Hypotension and hypertension are both associated with adverse outcomes. (See 'Postoperative care' above.)

●The perioperative mortality associated with CEA ranges from <0.5 to 3 percent. Complications associated with CEA include perioperative complications such as myocardial infarction; stroke; hyperperfusion syndrome; nerve injury; parotitis and bleeding, which can lead to neck hematoma requiring reoperation; and late carotid restenosis. (See 'Perioperative morbidity and mortality' above and "Complications of carotid endarterectomy".)

ACKNOWLEDGMENT — The editorial staff at UpToDate acknowledge Emile R Mohler, III, MD, now deceased, who contributed to an earlier version of this topic review. UpToDate also acknowledges Dr. Mohler's work as our Section Editor for Vascular Medicine.