Percutaneous transluminal angioplasty and stenting for vertebral artery stenosis

 

Abstract

Background

Surgery for vertebral artery stenosis is technically difficult, potentially hazardous and is not considered in most centres. There is growing evidence from case series that vertebral artery stenosis may be treated endovascularly by percutaneous transluminal angioplasty and stenting. This may be a feasible alternative to surgery to relieve symptoms caused by significant stenosis.

Objectives

To assess the safety and efficacy of vertebral artery percutaneous transluminal angioplasty, with or without stenting, combined with medical care, compared to medical care alone, in patients with vertebral artery stenosis.

Search methods

We searched the Cochrane Stroke Group's trials register (last searched 28 July 2004), the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 3, 2002), MEDLINE (1966 to July 2004), EMBASE (1980 to July 2004), and Science Citation Index (1981 to July 2004). We contacted researchers in the field, and balloon catheter and stent manufacturers.

Selection criteria

Randomised trials of endovascular treatment of vertebral artery stenosis combined with best medical therapy, compared with best medical therapy alone, in patients with symptomatic or asymptomatic vertebral artery stenosis.

Data collection and analysis

Two review authors independently applied the inclusion criteria, extracted data and assessed trial quality.

Main results

One completed randomised trial was found. In one subgroup of this trial, 16 patients with symptomatic severe vertebral artery stenosis were randomised to endovascular treatment (eight patients) or medical treatment alone (eight patients). There were no strokes in any arterial territory or deaths from any cause in either group within 30 days of treatment (endovascular group) or 30 days of randomisation (medical group). In the endovascular group, two patients had a posterior circulation transient ischaemic attack at the time of the procedure. In the endovascular group, the mean vessel stenosis at follow up was 47% (range 0% to 80%). Patients were followed up for a mean of 4.5 years in the endovascular group and 4.9 years in the medical group. There were no further vertebrobasilar territory strokes in either group for the duration of follow up. Morbidity and mortality was related to carotid and coronary artery disease in this study.

Authors' conclusions

There is currently insufficient evidence to assess the effects of percutaneous transluminal angioplasty with or without stenting or primary stenting for vertebral artery stenosis.

 

Plain language summary

Percutaneous transluminal angioplasty and stenting for vertebral artery stenosis

Currently there is insufficient evidence to support the use of endovascular treatment for vertebral artery stenosis in routine clinical practice. The vertebral arteries supply blood to the back of the brain and if narrowing (stenosis) of the artery occurs there is a risk of causing stroke. Because of difficulty accessing the vertebral artery, standard treatment has been conservative in most centres. The narrowing can also be treated by percutaneous transluminal balloon angioplasty. This involves passing a fine tube (catheter) through the skin (percutaneously) in to the arterial system. The catheter has a small balloon at its tip. The catheter is moved through the arterial system until the balloon reaches the point of arterial narrowing in the vertebral artery. The balloon is briefly inflated which stretches the artery (angioplasty) to reduce the degree of narrowing. Sometimes a device known as a stent is then placed inside the artery to prevent it narrowing again after the angioplasty. Angioplasty and stenting are called endovascular treatment. This review found results from one arm of a trial only involving a very small number of patients. The results suggest that endovascular treatment can be carried out with a high degree of technical success at the time of treatment but there is insufficient evidence to determine whether the risk benefit ratio favours endovascular intervention over conservative management. Randomised trials need to be designed to determine whether the endovascular treatment is more successful than conservative treatment at reducing the long term risk of stroke or death.

 

摘要

背景

經皮血管擴張術與支架用於椎動脈狹窄

椎動脈狹窄的手術在技術上是困難而有潛在危險的，並且在大多數國家都不被採用。有越來越多來自個案研究的證據顯示椎動脈狹窄或許可以經由血管內部藉經皮血管擴張術與支架置放來治療。這可能是一種可行的手術的替代方案，以減輕顯著狹窄所引發的症狀。

目標

此篇回顧論文的目的是評估在椎動脈狹窄的病人身上，椎動脈經皮血管擴張術，有或無合併支架置放，連同藥物治療，與單獨的藥物治療比較，其安全性與效益如何。

搜尋策略

我們搜尋Cochrane Stroke Group's trials register(搜尋至2004年7月28日)。此外我們搜尋以下目錄的資料庫：Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 3, 2002)， MEDLINE (1966年至2004年7月)， EMBASE (1980年至2004年7月)，以及 Science Citation Index (1981年至2004年7月)。我們同時聯絡此領域的研究者，與氣球導管和支架的製造商。

選擇標準

我們選擇了在有症狀或無症狀的椎動脈狹窄的病人身上，比較椎動脈狹窄的血管內治療合併最佳藥物治療，與單獨使用最佳藥物治療的隨機試驗(randomised trial)。

資料收集與分析

兩位檢閱者各自套用納入條件，篩選資料並評估試驗品質。

主要結論

我們找到一個完整的隨機試驗。在此試驗的一個分組中，16位有症狀的嚴重椎動脈狹窄病人被隨機分派到血管內治療(n = 8)或單獨藥物治療(n = 8)。在治療後的30天內(血管內治療組)或隨機分配後30天內(藥物治療組)兩組之中並沒有任何血管區域內的中風或是任何原因的死亡發生。在血管內治療組中，有兩位病人在治療執行時發生了後腦循環的暫時性腦缺血(TIA)。在血管內治療組中，追蹤的血管狹窄平均值是47%(從 0% 到 80%)。 在血管內治療組病人的平均追蹤期是4.5年，而在藥物治療組是4.9年。在追蹤期間兩組內都沒有再發生椎與基底動脈區域的中風。在此試驗中的罹病與死亡是來自於頸動脈與冠狀動脈疾病。

作者結論

目前來說並沒有充分的證據用以評估經皮血管擴張術有無合併支架或是直接置放支架用於椎動脈狹窄的效果。

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

目前並沒有充分的證據支持在臨床業務上常規使用血管內的方式治療椎動脈狹窄。椎動脈供給腦部後方的血流，而如果動脈發生窄化(狹窄)則有造成中風的危險。因為進入椎動脈的困難性，在大多數國家標準的治療方式一直是保守治療。動脈的狹窄也可以用經皮血管氣球擴張術來治療。這牽涉到使用一根細管(導管)穿過皮膚(經皮的)進入動脈系統。該導管在其頂端有一個小氣球。導管沿著動脈系統移動直到氣球達到椎動脈中狹窄的那一點。氣球短暫地充氣並撐開動脈(血管擴張術)以減少狹窄的程度。有時一種稱作支架的裝置會跟著被置入動脈內部以避免其在血管擴張術後再度狹窄。血管擴張術與支架置放被稱為血管內治療。這篇回顧只在一個試驗的其中一支 – 包含非常少的病人數 – 中發現到結果。該結果建議血管內治療可以在治療時高度成功的技術下被完成，但證據並不足以斷定風險利益比是否傾向血管內介入治療而非保守處置。我們需要隨機試驗以確定血管內治療是否比保守治療在降低長期中風或死亡的風險上更為成功。