Intervention Review

Carotid endarterectomy for asymptomatic carotid stenosis

  1. Brian R Chambers*,
  2. Geoffrey Donnan

Editorial Group: Cochrane Stroke Group

Published Online: 19 OCT 2005

Assessed as up-to-date: 3 NOV 2004

DOI: 10.1002/14651858.CD001923.pub2


How to Cite

Chambers BR, Donnan G. Carotid endarterectomy for asymptomatic carotid stenosis. Cochrane Database of Systematic Reviews 2005, Issue 4. Art. No.: CD001923. DOI: 10.1002/14651858.CD001923.pub2.

Author Information

  1. Austin Health, National Stroke Research Institute, Heidelberg Heights, Victoria, Australia

*Brian R Chambers, National Stroke Research Institute, Austin Health, Heidelberg Repatriation Hospital, 300 Waterdale Road, Heidelberg Heights, Victoria, 3081, Australia. brc@bigpond.net.au.

Publication History

  1. Publication Status: Edited (no change to conclusions)
  2. Published Online: 19 OCT 2005

SEARCH

 

Abstract

  1. Top of page
  2. Abstract
  3. Plain language summary
  4. 摘要

Background

Carotid endarterectomy (CEA) is of proven benefit in recently-symptomatic patients with severe carotid stenosis. Its role in asymptomatic stenosis is still debated. The Asymptomatic Carotid Surgery Trial (ACST) more than doubled the number of patients randomised to CEA trials. This revised review incorporates the recently published ACST results.

Objectives

To determine the effects of CEA for patients with asymptomatic carotid stenosis.

Search methods

We searched the Cochrane Stroke Group Trials Register (searched May 2004), MEDLINE (1966 to May 2004), EMBASE (1980 to June 2004), Current Contents (1995 to January 1997), and reference lists of relevant articles. We contacted researchers in the field to identify additional published and unpublished studies.

Selection criteria

All completed randomised trials comparing CEA to medical treatment in patients with asymptomatic carotid stenosis.

Data collection and analysis

Two reviewers extracted data and assessed trial quality. Attempts were made to contact investigators to obtain missing information.

Main results

Three trials with a total of 5223 patients were included. In these trials, the overall net excess of operation-related perioperative stroke or death was 2.9%. For the primary outcome of perioperative stroke or death or any subsequent stroke, patients undergoing CEA fared better than those treated medically (relative risk (RR) 0.69, 95% confidence interval (CI) 0.57 to 0.83). Similarly, for the outcome of perioperative stroke or death or subsequent ipsilateral stroke, there was benefit for the surgical group (RR 0.71, 95% CI 0.55 to 0.90). For the outcome of any stroke or death, there was a non-significant trend towards fewer events in the surgical group (RR 0.92, 95% CI 0.83 to 1.02). Subgroup analyses were performed for the outcome of perioperative stroke or death or subsequent carotid stroke. CEA appeared more beneficial in men than in women and more beneficial in younger patients than in older patients although the data for age effect were inconclusive. There was no statistically significant difference between the treatment effect estimates in patients with different grades of stenosis but the data were insufficient.

Authors' conclusions

Despite about a 3% perioperative stroke or death rate, CEA for asymptomatic carotid stenosis reduces the risk of ipsilateral stroke, and any stroke, by approximately 30% over three years. However, the absolute risk reduction is small (approximately 1% per annum over the first few years of follow up in the two largest and most recent trials) but it could be higher with longer follow up.

 

Plain language summary

  1. Top of page
  2. Abstract
  3. Plain language summary
  4. 摘要

Carotid endarterectomy for asymptomatic carotid stenosis

For most people with a narrowing of the carotid artery which is not causing symptoms a surgical operation to remove the narrowing carries a risk and has little benefit. Carotid stenosis is a narrowing of a major artery in the neck taking blood to the brain. This can cause a stroke. If the narrowing is severe and has caused symptoms, surgery to remove the narrowing (carotid endarterectomy) reduces the risk of stroke. However, if the narrowing has not caused any symptoms the risk of stroke is not very high. Although this low risk can be lowered further by surgery, the surgery itself can sometimes cause a stroke or death. The overall effect of surgery is a small benefit.

 

摘要

  1. Top of page
  2. Abstract
  3. Plain language summary
  4. 摘要

背景

頸動脈內膜切除術用於無症狀的頸動脈狹窄

頸動脈內膜切除術(CEA)被證實有益於近期有症狀的嚴重頸動脈狹窄病人。它在無症狀狹窄的病人身上角色仍有爭論。Asymptomatic Carotid Surgery Trial(ACST)的試驗人數超出CEA試驗隨機分派的病人數的兩倍之多。此篇修訂的回顧論文也包括了最近發表的ACST的結果。

目標

我們的目的是確定CEA對無症狀的頸動脈狹窄病人的效果。

搜尋策略

我們搜尋Cochrane Stroke Group Trials Register (搜尋至2004年5月),MEDLINE (1966年至2004年5月),EMBASE (1980年至2004年6月),Current Contents (1995年至1997年1月),以及相關文章的參考索引。我們聯絡該領域的研究者以確認更多已發表與未發表的研究。

選擇標準

所有已完成的隨機試驗(randomised trial)以比較CEA與藥物治療用於無症狀頸動脈狹窄的病人。

資料收集與分析

兩位檢閱者篩選資料並評估試驗品質。我們試圖聯絡研究者以取得遺漏的資訊。

主要結論

有3個試驗共計5223位病人被納入。在這些試驗當中,全部與手術相關的手術間期中風或死亡的淨增加率是2.9%。以手術間期中風或死亡,或其後的任何中風的初始結果(primary outcome)來說,接受CEA的病人的遭遇比那些受藥物治療的人來得好(相對風險(RR) 0.69, 95% 信賴區間(CI) 0.57 to 0.83)。相似地,對於手術間期的中風或死亡,或其後的同側性中風的預後來說,在手術組也有好處(RR 0.71, 95% CI 0.55 to 0.90)。以任何中風或死亡的預後來說,有一種非顯著性的趨勢是偏向手術組會有較少的事件發生(RR 0.92, 95% CI 0.83 to 1.02)。對於手術間期中風或死亡,或其後的頸動脈區域中風的預後,我們執行了分組分析。CEA顯示在男性比女性來得有利,以及在較年輕的病人比年老的病人來得有利,雖然在年紀的影響方面的資料並非決定性的。評估在不同狹窄等級的病人中,其治療的效果並沒有統計上的顯著差異,但資料並不足夠。

作者結論

雖然有約3%手術間期的中風或死亡率,CEA用在無症狀的頸動脈狹窄病人能降低同側性中風與任何中風的風險,在三年間約降低30%。然而,絕對風險的減少卻較低(在最新與最大的兩個試驗當中,於追蹤的最初幾年大約每年降1%),但在追蹤更久之後有可能會更高。

翻譯人

本摘要由奇美醫院陳軾正翻譯。

此翻譯計畫由臺灣國家衛生研究院(National Health Research Institutes, Taiwan)統籌。

總結

對於大多數無症狀性頸動脈狹窄的人來說,以外科手術移除其狹窄處帶來風險而且益處甚小。頸動脈狹窄是指攜帶血液至腦部的主要頸部動脈的窄化現象。這可能造成腦中風。如果這種狹窄嚴重並引發症狀,以手術移除其狹窄處(頸動脈內膜切除術)降低了中風的風險。然而,如果狹窄並未造成任何症狀,其中風的風險就不是非常高。雖然這種低度的風險可以進一步藉由手術來降低,手術本身有時候就會造成中風或死亡。整體的手術效益很小。