Carotid Endarterectomy

31.1Definition and clinical presentation

Carotid endarterectomy is an open surgical procedure designed to remove atheromatous plaque from the carotid bifurcation to prevent future stroke, first described for recurrent hemispheric ischemia in 1954 Eastcott · 1954. The procedure is evaluated across two distinct clinical presentations:

• Symptomatic disease: defined by recent ipsilateral retinal or hemispheric ischemic events, including transient ischemic attack, amaurosis fugax, or non-disabling stroke.
• Asymptomatic disease: stenosis detected incidentally or by screening without recent ipsilateral neurologic symptoms.

Baseline antithrombotic management relies on short-course dual antiplatelet therapy for minor stroke or high-risk transient ischemic attack, transitioning to single antiplatelet therapy tailored to the balance of bleeding and ischemic risk around the time of surgery AHA/ASA 2021.

31.2Treatment decision and operative thresholds

The treatment decision rests on validating the symptom link, measuring stenosis severity, confirming adequate life expectancy, and proving acceptable institutional perioperative complication rates.

Management decisions follow a stepwise sequence:

1. Symptomatic status, stenosis severity, and timing relative to the qualifying event govern the initial classification.
2. Perioperative risk is measured against strict quality gates (<= 6% stroke or death for symptomatic patients, <= 3% for asymptomatic patients) to determine eligibility.
3. Endarterectomy is preferred for average-risk anatomy, particularly in patients aged >= 70 years.
4. Carotid artery stenting is reserved for hostile neck anatomy or high physiologic surgical risk.
5. Intervention is deferred outside the operative framework if neurologic stability is compromised, the infarct is large, or hemorrhagic transformation risk is high.

31.3Symptomatic disease and intervention timing

Carotid endarterectomy delivers its greatest absolute benefit in high-grade symptomatic stenosis. In the NASCET trial, endarterectomy for symptomatic 70 to 99% stenosis yielded an approximate 17 percentage-point absolute risk reduction in 2-year ipsilateral stroke compared to medical therapy NASCET · 1991. The ECST trial, using a different measurement method, demonstrated an approximate 11.6% absolute reduction in 3-year major stroke or death for patients with >= 80% stenosis by the ECST criteria ECST · 1998.

Benefit in moderate symptomatic stenosis (50 to 69%) is smaller and highly selective. In the NASCET 50 to 69% subgroup, benefit was concentrated in men and in patients operated on within a few weeks of the qualifying event NASCET · 1991. Patient sex substantially modifies the expected benefit across all symptomatic bands: pooled NASCET and ECST data report an approximate 5-year number needed to treat to prevent one ipsilateral stroke of 9 for men, compared to 36 for women Rothwell 2004 · ECST · 1998.

Timing is the primary determinant of outcome in symptomatic disease. Benefit declines sharply, and the number needed to treat rises steeply, when endarterectomy is delayed beyond 2 weeks after a transient ischemic attack or minor stroke Rothwell 2004 · ECST · 1998 · NASCET · 1991. The EXPRESS study demonstrated that urgent workup and rapid treatment pathways significantly reduce early recurrent stroke EXPRESS 2007. Consequently, endarterectomy is ideally performed within 14 days of the qualifying event for 50 to 99% symptomatic stenosis ESVS 2023 · ESO 2021. Hyperacute operation (< 48 hours) carries elevated perioperative risk and requires individualized assessment CREST · 2010.

31.4Asymptomatic disease

In asymptomatic disease, the absolute stroke-prevention benefit is comparatively small and is highly vulnerable to perioperative complications. In the ACAS trial, endarterectomy for 60 to 99% asymptomatic stenosis achieved an approximate 5.9% absolute risk reduction in 5-year aggregate stroke versus historical medical therapy ACAS · 1995.

The ACST-1 trial confirmed durable 10-year benefit but exclusively in centers keeping perioperative stroke or death below approximately 3% ACST-1 2010. In the ACST-1 immediate-endarterectomy arm, the 30-day perioperative stroke or death rate was approximately 3.0%, generating a 5-year non-perioperative stroke rate of 4.1%, compared to 10.0% in the deferred-intervention medical arm. Without strict control of center-level perioperative risk to <= 3%, the long-term prophylactic advantage of asymptomatic endarterectomy is lost.

31.5Modality selection: endarterectomy versus stenting

Carotid endarterectomy is the default intervention for average-risk symptomatic 70 to 99% stenosis, whereas carotid artery stenting is reserved for patients with documented high surgical risk or hostile cervical anatomy SVS 2022. Symptomatic stenting carries a substantial early hazard; the EVA-3S trial was terminated early when stenting demonstrated a 30-day stroke or death rate of 9.6% compared to 3.9% for endarterectomy, an approximate 2.5-fold relative risk increase EVA-3S 2006.

Overall comparative evidence defines an explicit tradeoff boundary. In the CREST trial, 4-year primary composite outcomes were similar between modalities overall, but stenting caused more periprocedural strokes, while endarterectomy caused more periprocedural myocardial infarctions and carries cranial-nerve injury risk Bonati Cochrane · 2020 · CREST · 2010. A strong age interaction governs selection: patients aged 70 years or older experience lower periprocedural stroke rates with endarterectomy than with stenting, establishing open surgery as the preferred modality in this older demographic ESVS 2023. In asymptomatic patients, the ACST-2 trial reported similar 5-year non-disabling stroke rates between endarterectomy and stenting in credentialed centers ACST-2 2021.

31.6Operative technique and surveillance

Standard operative technique requires explicit protocol-driven decisions regarding patch versus primary closure, longitudinal versus eversion arteriotomy, and shunting and monitoring strategies. Patch angioplasty and primary closure outcomes are audited at the institution level to assess restenosis and neurologic events Cochrane 2009.

Postoperative surveillance monitors for restenosis, occlusion, pseudoaneurysm, and recurrent symptoms. Obtain a baseline carotid duplex within roughly 30 days of endarterectomy, repeat at 6 months, and then annually, concentrating surveillance on the first 2 years when restenosis risk is highest; ipsilateral or contralateral disease drives continued follow-up SVS 2022. Carotid endarterectomy demonstrates a superior durability profile, with lower long-term restenosis rates compared to carotid artery stenting across pooled randomized trials Bonati Cochrane · 2020. The detection of restenosis triggers a review of the original closure method and informs modality selection for any necessary reintervention.

31.7Areas of controversy

The magnitude of asymptomatic operative benefit remains an active controversy. The ACAS and ACST-1 results reflect historical medical therapy baselines; the incremental absolute risk reduction of prophylactic carotid endarterectomy over contemporary, highly intensive lipid and blood-pressure management is not definitively quantified SVS 2022 · ACST-1 2010 · ACAS · 1995. CREST-2 is designed to settle this question: two parallel NIH-funded randomized trials assign patients with asymptomatic 70% or greater stenosis to revascularization plus intensive medical management versus intensive medical management alone, one arm testing endarterectomy and the other stenting, directly measuring whether revascularization adds benefit over modern best medical therapy; enrollment is complete and results are awaited CREST-2 2017.

Patch material selection lacks a universally superior agent. Cochrane review evidence comparing Dacron, PTFE, and vein patches relies on low-certainty data with wide confidence intervals. One comparison associated PTFE with higher long-term stroke or death than Dacron, while vein patches definitively carry a higher late risk of pseudoaneurysm formation Cochrane 2021.

Shunting policy (routine, selective, or none) during endarterectomy under general anesthesia also remains unresolved. Systematic reviews show no statistically significant difference in 30-day stroke or death among shunting strategies, and no intraoperative monitoring method has proven uniformly superior to guide selective insertion Cochrane 2014.