The National Institute for Clinical Excellence is examining supraorbital minicraniotomy for intracranial aneurysm and will publish guidance on its safety and efficacy to the NHS in England and Wales. The Institute's Interventional Procedures Advisory Committee has considered the available evidence and the views of Specialist Advisors, who are consultants with knowledge of the procedure. The Advisory Committee has made provisional recommendations about supraorbital minicraniotomy for intracranial aneurysm.

This document has been prepared for public consultation. It summarises the procedure and sets out the provisional recommendation made by the Advisory Committee.

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 the Final Interventional Procedure Document (FIPD) and submit it to the Institute.
• The FIPD may be used as the basis for the Institute's guidance on the use of the procedure in the NHS in England and Wales.

For further details, see the Interim Guide to the Interventional Procedures Programme, which is available from the Institute's website (www.nice.org.uk/ip).

Closing date for comments: 23 December 2003

Target date for publication of guidance: March 2004

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

Current evidence on the safety and efficacy of supraorbital minicraniotomy for intracranial aneurysm does not appear adequate for this procedure to be used without special arrangements for consent and for audit or research. Clinicians wishing to undertake supraorbital minicraniotomy for intracranial aneurysm should inform the clinical governance leads in their Trusts. They should ensure that patients offered it understand the uncertainty about the procedure's safety and efficacy and should provide them with clear written information. Use of the Institute's Information for the Public is recommended. Clinicians should ensure that appropriate arrangements are in place for audit and research. Publication of safety and efficacy outcomes will be useful in reducing the current uncertainty. NICE is not undertaking further investigation at present.

Aneurysms are dilated portions of blood vessels that may rupture, causing stroke.

The standard surgical approach to aneurysms in the front and middle parts of the skull (the anterior, middle and pituitary fossae) is through a large incision in the bone to expose a large section of the brain surface. Aneurysms are usually clipped to separate them from the blood vessel they arise from. If clipping is not possible, the aneurysm may be wrapped with synthetic material to reduce the risk of rupture.

Supraorbital minicraniotomy is a minimally invasive approach through a small incision made above the eyebrow. A larger incision is then made in the skull. The aneurysm is then clipped or wrapped using conventional microsurgical instruments.

No controlled studies were identified. In two studies all the aneurysms were either successfully clipped or wrapped, but length of follow-up was not reported. In another study, 33 out of 37 patients showed good recovery on the Glasgow Outcome Scale, but it was not clear how many of the patients were followed up for the entire 17 months referred to in the paper. This study also reported good cosmetic outcomes following surgery. For more details, refer to the sources of evidence below (see Appendix).

One Specialist Advisor considered it unlikely that the efficacy of treating an aneurysm would be affected by the small exposure used in this procedure when compared with the standard surgical approach.

In the three case series reviewed, rupture of the aneurysm during surgery occurred in 4/139 patients, 2/102 patients and 1/37 patients. Other adverse events were: death within 8 days of surgery (4/102 patients); central nervous system infection (2/102 patients); impaired cerebral spinal fluid (CSF) circulation requiring shunting (7/102 patients); supraorbital nerve damage (4/37 patients); and wound infection (1/37 patients). For more details, refer to the sources of evidence (see Appendix).

The Specialist Advisors considered that it would be more difficult to deal with intraoperative rupture using this procedure.

The Advisory Committee commented that this procedure involves a different surgical approach for performing an established procedure (craniotomy for intracranial aneurysm), however it may introduce new risks as pre-operative rupture may be more difficult to control.

The Committee recognised that there is an increasing trend to deal with aneurysms by endoluminal techniques.

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

• Interventional Procedure Overview of Supraorbital minicraniotomy for intracranial aneurysm, December 2002

Available from: www.nice.org.uk/ip015overview