Carotid endarterectomy for symptomatic carotid stenosis
C S Cina1, C M Clase, R B Haynes
1Department of Surgery, Division of Vascular Surgery, Victoria Medical Centre, Suite 305, 304 Victoria Avenue North, Hamilton, Ontario, Canada, L8N 5G4. cinacs@fhs.csu.mcmaster.ca
Insights
Carotid endarterectomy significantly reduces stroke risk in patients with severe carotid stenosis. However, surgery may increase stroke risk for those with less severe narrowing, emphasizing careful patient selection.
Area of Science:
- Neurology
- Vascular Surgery
- Evidence-Based Medicine
Background:
- Severe carotid artery stenosis is a major stroke risk factor.
- Carotid endarterectomy (CEA) can mitigate stroke risk but involves surgical complications.
Purpose of the Study:
- To review randomized controlled trials on the efficacy and safety of CEA in symptomatic carotid stenosis.
- To evaluate the risk-benefit balance of CEA versus best medical treatment.
Main Methods:
- Systematic review of randomized controlled trials comparing CEA plus best medical treatment with best medical treatment alone.
- Searched Cochrane Stroke Group's Specialized Register and other databases up to March 1999.
- Intention-to-treat analysis of data from the NASCET and ECST trials.
Main Results:
- For severe stenosis (ECST > 80% or NASCET > 70%), CEA reduced the relative risk of disabling stroke or death by 48% (NNT = 15).
- For less severe stenosis (ECST 70-79% or NASCET 50-69%), CEA reduced the relative risk by 27% (NNT = 21).
- Patients with lesser degrees of stenosis experienced an increased risk of disabling stroke or death (20% increase).
Conclusions:
- CEA is beneficial for patients with symptomatic carotid stenosis greater than ECST 70% or NASCET 50%.
- Benefits are limited to surgically-fit patients treated by surgeons with <6% complication rates.
- CEA may be harmful in patients with less severe stenosis.
Background:
Severe narrowing (or stenosis) of the carotid artery is an important cause of stroke. Surgical removal of the atheromatous material from the inside of the carotid artery (endarterectomy) may reduce the risk of stroke, but carries a risk of operative complications.
Objectives:
This review seeks to summarize the evidence from randomized trials on the balance of risks and benefits of carotid endarterectomy in adults with symptomatic carotid stenosis.
Search Strategy:
We searched the Cochrane Stroke Group's Specialized Register of trials (date last searched: March 1999), supplemented by electronic searches of several databases.
Selection Criteria:
Randomized controlled trials comparing 'best medical treatment plus carotid endarterectomy' with 'best medical therapy' in patients with carotid stenosis and a recent transient ischaemic attack or nondisabling ischaemic stroke in the territory of that artery.
Data Collection And Analysis:
Two reviewers independently selected the studies and extracted the data. An intention to treat analysis was performed.
Main Results:
Data on death or disabling stroke were available from two trials, which included 5950 patients: the North American Symptomatic Carotid Endarterectomy Trial (NASCET), and the European Carotid Surgery Trial (ECST). The two trials used different methods to measure stenosis, but a simple formula can be used to convert between the two methods. For patients with severe stenosis (ECST > 80% = NASCET > 70%), surgery reduced the relative risk of disabling stroke or death by 48% (95% confidence interval [CI] 27 - 73%). The number of patients needed to be operated on (number needed to treat [NNT]) to prevent one disabling stroke or death over 2 to 6 years follow-up was 15 (95% CI 10 - 31). For patients with less severe stenosis (ECST 70 - 79% = NASCET 50 - 69%), surgery reduced the relative risk of disabling stroke or death by 27% (95% CI 15 - 44%). The number of patients needed to be operated on to prevent one disabling stroke or death was 21 (95% CI 11 - 125). Patients with lesser degrees of stenosis were harmed by surgery. Surgery increased the risk of disabling stroke or death by 20% (95% CI 0 - 44%). The number of patients needed to be operated on to cause one disabling stroke or death was 45 (95% CI 22 - infinity).
Reviewer'S Conclusions:
Carotid endarterectomy reduced the risk of disabling stroke or death for patients with stenosis exceeding ECST-measured 70% or NASCET-measured 50%. This result is generalizable only to surgically-fit patients operated on by surgeons with low complication rates (less than 6%).
Related Concept Videos
01:27Coronary Artery Disease V: Interprofessional Care
01:26Aneurysm III: Interprofessional Care
01:26Atherosclerosis III: Management
01:27Peripheral Artery Disease III: Interprofessional Care
01:27Atherosclerosis II: Clinical Manifestations and Diagnostic Tests
01:26Angina IV: Management