Interventional procedure consultation document

Endovascular stent insertion for intracranial atherosclerotic disease

Improving blood flow to the brain by widening a narrowed artery inside the head using an expandable tube

Intracranial atherosclerotic disease (ICAD) is the narrowing of the arteries inside the head that supply blood to the brain. ICAD is associated with an increased risk of stroke. In this procedure, a balloon catheter is inserted into an artery in the arm or leg, guided to the affected artery and inflated to open up the narrowing. A small tube made of metal mesh, called a stent, is then positioned at the site of the narrowing to maintain improved blood flow.

The National Institute for Health and Clinical Excellence (NICE) is examining endovascular stent insertion for intracranial atherosclerotic disease and will publish guidance on its safety and efficacy to the NHS in England, Wales, Scotland and Northern Ireland. NICE’s Interventional Procedures Advisory Committee has considered the available evidence and the views of Specialist Advisers, who are consultants with knowledge of the procedure. The Advisory Committee has made provisional recommendations about endovascular stent insertion for intracranial atherosclerotic disease.

This document summarises the procedure and sets out the provisional recommendations made by the Advisory Committee. It has been prepared for public consultation. The Advisory Committee particularly welcomes:

• comments on the provisional recommendations
• the identification of factual inaccuracies
• additional relevant evidence, with bibliographic references where possible.

Note that this document is not NICE’s formal guidance on this procedure. The recommendations are provisional and may change after consultation.

The process that NICE will follow after the consultation period ends is as follows.

• The Advisory Committee will meet again to consider the original evidence and its provisional recommendations in the light of the comments received during consultation.
• The Advisory Committee will then prepare draft guidance which will be the basis for NICE’s guidance on the use of the procedure in the NHS in England, Wales, Scotland and Northern Ireland.

For further details, see the Interventional Procedures Programme manual, which is available from the NICE website (www.nice.org.uk/ipprogrammemanual).

Through its guidance NICE is committed to promoting race and disability equality, equality between men and women, and to eliminating all forms of discrimination. One of the ways we do this is by trying to involve as wide a range of people and interest groups as possible in the development of our interventional procedures guidance. In particular, we aim to encourage people and organisations from groups who might not normally comment on our guidance to do so.

In order to help us promote equality through our guidance, we should be grateful if you would consider the following question:

Are there any issues that require special attention in light of NICE’s duties to have due regard to the need to eliminate unlawful discrimination and promote equality and foster good relations between people with a characteristic protected by the equalities legislation and others?

Please note that NICE reserves the right to summarise and edit comments received during consultations or not to publish them at all where in the reasonable opinion of NICE, the comments are voluminous, publication would be unlawful or publication would otherwise be inappropriate.

Closing date for comments: 20 March 2012

Target date for publication of guidance: June 2012

1   Provisional recommendations

1.1   Current evidence on the efficacy of endovascular stent insertion for intracranial atherosclerotic disease shows no substantial differences in clinical outcomes compared with medical treatment after 1–2 years. Evidence on its safety shows that there is a significant risk of periprocedural stroke and death. Therefore, this procedure should only be used in the context of research. Research should clearly define patient selection and be designed to provide outcome data based on follow-up of at least 2 years.

2   The procedure

2.1   Indications and current treatments

2.1.1   Intracranial atherosclerotic disease (ICAD) is the narrowing or obstruction of arteries within the skull that supply blood to the brain. It is caused by atheromatous plaques, which can reduce blood flow and may be associated with thrombosis or embolism, leading to transient ischaemic attacks (TIA), stroke or death. ICAD is usually diagnosed only after a patient has presented with a TIA or stroke.

2.1.2   Symptomatic ICAD is usually treated with antiplatelet medication together with a statin and attention to risk factors for atherosclerosis such as smoking, hypertension, diabetes and obesity.

2.1.3   Direct intervention to treat the ICAD is not commonly used. It can be done by balloon angioplasty to dilate arterial lesions.The aim of stent insertion is to improve patency.

2.2   Outline of the procedure

2.2.1   The procedure is carried out with the patient under general or local anaesthesia. Under fluoroscopic control, a catheter is introduced percutaneously through an artery in the arm or leg and guided into the affected intracranial artery. Balloon angioplasty of the target lesion is normally done to dilate it before inserting a stent. It is possible to insert more than one stent or to treat more than one lesion in a treatment session.

2.2.2   Two main types of stent have been used – balloon expandable and self-expanding. Some studies have also used drug-eluting stents. The technology has evolved over the past decade and continues to do so.

Sections 2.3 and 2.4 describe efficacy and safety outcomes from the published literature that the Committee considered as part of the evidence about this procedure. For more detailed information on the evidence, see the overview, available at www.nice.org.uk/guidance/IP/386/overview

2.3   Efficacy

2.3.1   The efficacy outcomes described below include stroke or death occurring more than 30 days after the procedure (unless specified otherwise). Stroke or death occurring on or before 30 days are included as safety outcomes.

2.3.2   A randomised controlled trial (RCT) of 451 patients treated by angioplasty and stent insertion or medical management alone reported ischaemic stroke in the area of the brain supplied by the index arterial lesion beyond 30 days after enrolment in 6% of patients in both groups (13/224 and 13/227, respectively, p value not stated) at a mean follow-up of 12-months. A case series of 158 patients reported that 20% (22/110) of patients had a stroke or TIA between 30 days and 12 months after the procedure. A case series of 213 patients reported lesion-related ischaemic stroke after 30 days in 3% (7/213) of patients, with a mean follow-up of 27 months.

2.3.3   The RCT of 451 patients reported a death rate of 3% in both groups (7/224 and 7/227, respectively, p = 0.95) at a mean follow-up of 12-months. A systematic review comparing 36 studies of angioplasty and endovascular stent insertion with 33 studies of angioplasty alone reported stroke and/or death in 12% (123/1070) and 17% (125/731) of patients respectively at 1-year follow-up (p = 0.0002).

2.3.4   A case series of 113 patients reported an overall restenosis rate of 18% (16/89; identified by transcranial Doppler ultrasound or angiography) at a mean follow-up of 29 months. The case series of 213 patients reported an overall restenosis rate of 19% (19/99) identified on follow-up angiography at a mean follow-up of 9 months.

2.3.5   The Specialist Advisers listed key efficacy outcomes as reduction in TIA or stroke frequency.

2.4   Safety

2.4.1   The RCT of 451 patients treated by angioplasty and stent insertion or by medical management alone reported stroke or death within 30 days of enrolment in 15% (33/224) and 6% (13/227) of patients, respectively (p = 0.002). There were 5 stroke-related deaths in the stent group and 1 non-stroke-related death in the medical management group. A systematic review comparing 36 studies of angioplasty and endovascular stent insertion with 33 studies of angioplasty alone reported stroke and/or death in 8% (104/1291) and 9% (91/1027) of patients respectively at 1-month follow-up (p = 0.49).

2.4.2   Stent occlusion occurred in 4% (2/53) of patients treated by endovascular stent insertion in a non-randomised comparative study. One occlusion occurred 2 days after stent insertion and the patient underwent extracranial-intracranial bypass surgery because of recurrent TIAs. The second occlusion occurred 9 days after stent insertion in a patient who was not receiving antiplatelet medication because of a gastrointestinal haemorrhage; the patient had a stroke and died.

2.4.3   Vessel rupture during stent navigation was reported in 2% (2/113) of patients in the case series of 113 patients; 1 patient died of massive subarachnoid haemorrhage, and the other was treated by emergency craniotomy and surgical clipping of the middle cerebral artery.

2.4.4   Bilateral intracerebral haemorrhage was reported in 1 patient in the case series of 113 patients, 2 weeks after the procedure. Symptomatic subarachnoid haemorrhage (not otherwise described) was reported in 1% (2/213) of patients and symptomatic brain haemorrhage (not otherwise described) was reported in 1 patient, within 30 days of the procedure, in the case series of 213 patients.

2.4.5   Specialist Advisers listed anecdotal adverse events as basilar artery rupture resulting in death, disabling thalamic infarct, and reperfusion haemorrhage. They stated that theoretical adverse events included vessel dissection, embolisation, myocardial infarction, groin haematoma and contrast reactions.

2.5   Other comments

2.5.1   The Committee noted that a number of different devices have been used for endovascular stent insertion for intracranial atherosclerotic disease and that technical evolution of devices is continuing.

2.5.2   The Committee also noted that medical management is variable and continues to evolve. This complicates interpretation of studies that compare the procedure with medical treatment.

3   Further information

3.1   This guidance is a review of ‘Endovascular stent insertion for intracranial atherosclerotic disease’ NICE interventional procedures guidance 233 (2007).

3.2   For related NICE guidance see www.nice.org.uk.

Bruce Campbell

Chairman, Interventional Procedures Advisory Committee

February 2012

_{Personal data will not be posted on the NICE website. In accordance with the Data Protection Act names will be anonymised, other than in circumstances where explicit permission has been given. It is the responsibility of consultees to accurately cite academic work in order that they can be validated.}