Laser-assisted non-occlusive cerebral vascular anastomosis without temporary arterial occlusion (interventional procedures consultation)

NATIONAL INSTITUTE FOR HEALTH AND CLINICAL EXCELLENCE

Interventional Procedure Consultation Document

Laser-assisted cerebral vascular anastomosis without temporary arterial occlusion

Arteries in the head may need to be bypassed as part of an operation, usually because of 'ballooning' or blockage of arteries. Laser-assisted cerebral vascular anastomosis without temporary arterial occlusion aims to create a bypass without the need to temporarily interrupt the blood flow to the brain.


The National Institute for Health and Clinical Excellence is examining laser-assisted cerebral vascular anastomosis without temporary arterial occlusion and will publish guidance on its safety and efficacy to the NHS in England, Wales, Scotland and Northern Ireland. The Institute'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 laser-assisted cerebral vascular anastomosis without temporary arterial occlusion.

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 preliminary recommendations
  • the identification of factual inaccuracies
  • additional relevant evidence.

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

The process that the Institute 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  • The Advisory Committee will then prepare draft guidance which will be the basis for the Institute's guidance on the use of the procedure in the NHS in England, Wales, Scotland and Northern Ireland.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 Institute's website (www.nice.org.uk/ipprogrammemanual).

NICE is committed to promoting through its guidance race and disability equality and 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 guidance on interventional procedures. In particular, we aim to encourage people and organisations from groups in the population who might not normally comment on our guidance to do so. We also ask consultees to highlight any ways in which draft guidance fails to promote equality or tackle discrimination and how it might be improved.

Closing date for comments: 20 November 2007
Target date for publication of guidance: February 2008


Note that this document is not the Institute's guidance on this procedure. The recommendations are provisional and may change after consultation.


1 Provisional recommendations
1.1 Current evidence on the safety and efficacy of laser-assisted cerebral vascular anastomosis without temporary arterial occlusion is based on very limited numbers of patients. Therefore the procedure should only be used with special arrangements for clinical governance, consent and for audit or research.
1.2

Clinicians wishing to undertake laser-assisted cerebral vascular anastomosis without temporary arterial occlusion should take the following actions.

  • Inform the clinical governance leads in their Trusts.
  • Ensure that patients understand the uncertainty about the procedure's safety and efficacy and provide them with clear written information. In addition, use of the Institute's information for patients ('Understanding NICE guidance') is recommended (available from www.nice.org.uk/IPG XXX publicinfo). [[details to be completed at publication]]
  • Audit and review clinical outcomes of all patients having laser-assisted cerebral vascular anastomosis without temporary arterial occlusion (see section 3.1).
1.3 Selection of patients for this procedure should be carried out in the context of a multidisciplinary team including a neurosurgeon and an interventional neuroradiologist.
1.4 Publication of safety and efficacy outcomes will be useful. The Institute may review the procedure upon publication of further evidence.

 

2 The procedure
2.1 Indications
2.1.1 Aneurysms and other abnormalities of arteries supplying the brain may be suitable for treatment by open surgery or endovascular techniques, such as insertion of coils or stents. In some cases, arterial bypass of an abnormality may be necessary. This is achieved either by direct anastomosis between branches of the external carotid and internal carotid arteries or by an interposition saphenous vein or radial artery graft. In both techniques there is a risk of stroke because there is a temporary occlusion of the cerebral blood supply while the anastomosis to the intracranial artery is performed.
2.2 Outline of the procedure
2.2.1 The laser-assisted non-occlusive anastomosis technique aims to achieve cerebral arterial bypass without the need for temporary arterial occlusion, thus maintaining the cerebral blood flow throughout the procedure.
2.2.2 The procedure is performed under general anaesthesia. The distal (cerebral) anastomosis site is prepared by stitching a platinum ring onto the wall of the recipient vessel. The bypass graft is sutured end-to-side to the recipient vessel outside the ring. A combined laser-vacuum-suction catheter is introduced through the bypass graft into the platinum ring on the wall of the recipient vessel. Using vacuum suction and laser pulses, a disc-shaped area is resected in the wall of the recipient vessel. This punched-out disc is withdrawn while still attached to the vacuum catheter, completing the anastomosis without interrupting the cerebral blood flow. The graft is then temporarily clipped to prevent backflow whilst the wall of this vessel is closed (in direct extracranial/intracranial bypass) or the proximal anastomosis is formed (in indirect interposition extracranial/intracranial bypass). When interposition grafts are used, the proximal anastomosis is performed using a standard end to-end or end-to-side anastomosis.
2.3 Efficacy
2.3.1 In a case series of 77 patients with intracranial aneurysms undergoing bypass using laser-assisted cerebral vascular anastomosis without temporary arterial occlusion, a patient high-flow bypass was successfully created in 97% (75/77) of cases. Anastomosis failed in 3% (2/77) of cases because the excised section of the targeted artery wall did not attach to the laser tip on withdrawal. A second procedure was required in 8 patients (10%), usually because of post-operative graft thrombosis.
2.3.2 In a third case series of 15 patients with carotid artery occlusion and recurrent ischaemic symptoms, transcranial Doppler ultrasound on 11 patients who survived to 6 months showed that a patent bypass was established in 91% (10/11).
2.3.3 In the two case series of 77 and 34 patients, 68% (52/77) and 79% (27/34) of patients were independent (using the modified Rankin scale) at 2-4 months' and 3.3 years' follow-up, respectively. In the first study, functional health improved in 14% (11/77) of patients, was unchanged in 65% (50/77) and had decreased in 21% (16/77) at 2-4 months' follow-up. In the second study, Rankin score (a measure of functional capacity) had improved in 71% (24/34) of patients at discharge and 74% (25/34) at 3.3 years' follow-up. Of the 27 patients who had pre-existing cranial nerve compression in the second study, 30% (10/27) resolved at the same follow-up. For more details, refer to the sources of evidence (see appendix).
2.3.4 The Specialist Advisers considered key efficacy outcomes to be graft patency (including angiographic assessment) without further stenosis and lack of haemorrhage during the procedure.
2.4 Safety
2.4.1 Postoperative mortality (up to 30 days' follow-up) following laser assisted cerebral vascular anastomosis without temporary arterial occlusion was reported to be 4% (3/77), 6% (2/34), 7% (1/15), and 0% (0/1). The indication for the procedure varied between studies.
2.4.2 The case series of 77 patients with intracranial artery aneurysms in whom the procedure was used reported that ischaemia causing persistent deficit occurred in 21% (16/77), haemorrhage causing persistent deficit occurred in 5% (4/77) and other intracranial events causing persistent deficit occurred in 3% (2/77). Procedure related complications resulting in a Rankin score of 3-5 occurred in 9% (7/77) of patients.
2.4.3 A case series of 15 patients with carotid artery occlusion reported that ischaemic stroke occurred in 20% (3/15) of patients and dysphasia with right-sided weakness occurred in 13% (2/15). For more details, refer to the sources of evidence (see appendix).
2.4.4 The Specialist Advisers considered the theoretical adverse events of the procedure to include laser damage to the bypass vessel wall and leakage or late stenosis of the anastomosis.
3 Further information
3.1 This guidance requires that clinicians undertaking the procedure make special arrangements for audit. The Institute has identified relevant audit criteria and is developing an audit tool (which is for use at local discretion), which will be available when the guidance is published.
3.2 The Institute has produced interventional procedures guidance on high-flow interposition extracranial to intracranial bypass (www.nice.org.uk/IPG073).
   

Bruce Campbell
Chairman, Interventional Procedures Advisory Committee
October 2007

Appendix: Sources of evidence
 

The following document, which summarises the evidence, was considered by the Interventional Procedures Advisory Committee when making its provisional recommendations.

  • 'Interventional procedure overview of laser-assisted cerebral vascular anastomosis without temporary arterial occlusion, June 2007'.

Available from: www.nice.org.uk/ip411overview.

This page was last updated: 30 March 2010