Endovascular stents for abdominal aortic aneurysms: a systematic review and economic model

Authors: Chambers D, Epstein D, Walker S, Fayter D, Paton F, Wright K, Michaels J, Thomas S, Sculpher M, Woolacott N

Journal: Health Technology Assessment Volume: 13 Issue: 48

Publication date: October 2009

DOI: 10.3310/hta13480

Citation:

Chambers D, Epstein D, Walker S, Fayter D, Paton F, Wright K, et al.Endovascular stents for abdominal aortic aneurysms: a systematic review and economic model. Health Technol Assess 2009;13(48)


Download: Citation (for this publication as a .ris file) (4.0 KB)


Journal issues* can be purchased by completing the form.


The cost of reports varies according to number of pages and postage address. The minimum cost for a copy sent to a UK address is £30.00. We will contact you on receipt of your completed form to advise you of actual cost. If you have any queries, please contact nihredit@southampton.ac.uk.


*We regret that unfortunately we are unable to supply bound print copies of Health Technology Assessment published before issue 12:31. However, PDFs are available to print from the "Downloads" tab of the issue page.

Responses

No responses have been published. If you would like to submit a response to this publication, please do so using the form below.

Comments submitted to the NIHR Journals Library are electronic letters to the editor. They enable our readers to debate issues raised in research reports published in the Journals Library. We aim to post within 2 working days all responses that contribute substantially to the topic investigated, as determined by the Editors.

Your name and affiliations will be published with your comment.

Once published, you will not have the right to remove or edit your response. The Editors may add, remove, or edit comments at their absolute discretion.

Post your response

Surname

Forename

Middle Initial

Occupation / Job title

Affiliation / Employer

Email

Address

Other authors

For example, if you are responding as a team or group. Please ensure you include full names and separate these using commas

Statement of competing interests

We believe that readers should be aware of any competing interests (conflicts of interest).

The International Committee of Medical Journal Editors (ICMJE) define competing interests as including: financial relationships with industry (for example through employment, consultancies, stock, ownership, honoraria, and expert testimony), either directly or through immediate family; personal relationships; academic competition; and intellectual passion.

If yes, provide details below:

Enter response title

Enter response message

Enter CAPTCHA

Security key

Regenerate security key

By submitting your response, you are stating that you agree to the terms & conditions

The full text of this issue is available as a PDF document from the Downloads section on this page.

Abstract

Objective

To determine the clinical effectiveness and cost-effectiveness of endovascular aneurysm repair (EVAR) of infrarenal abdominal aortic aneurysms (AAAs) in patients at varying levels of risk.

Data sources

The following bibliographic databases were searched (2005-February 2007): BIOSIS Previews, CINAHL, Cochrane Central Register of Controlled Trials, EMBASE, ISI Proceedings, MEDLINE, MEDLINE In-Process & Other Non-Indexed Citations, Science Citation Index and Zetoc Conferences.

Review methods

A systematic review of the clinical effectiveness of EVAR was performed using standard methods. Meta-analysis was employed to estimate a summary measure of treatment effect on relevant outcomes based on intention to treat analyses. A second systematic review was undertaken to identify existing cost-effectiveness analyses of EVAR compared with open surgery and non-surgical interventions. Two new decision models were developed to inform the review.

Results

Six RCTs were included in the clinical effectiveness review. Thirty-four studies evaluated the role of patients' baseline characteristics in predicting risks of particular outcomes after EVAR. The majority were based on data relating to devices in current use from the EUROSTAR registry. Compared with open repair EVAR reduces operative mortality (odds ratio 0.35, 95% CI 0.19 to 0.63) and medium-term aneurysm-related mortality (hazard ratio 0.49, 95% CI 0.29 to 0.83) but offers no significant difference in all-cause mortality. EVAR is associated with increased rates of complications and reinterventions, which are not offset by any increase in health-related quality of life. EVAR trial 2 comparing EVAR with non-surgical management in patients unfit for open repair found no differences in mortality between groups; however, substantial numbers of patients randomised to non-surgical management crossed over to receive surgical repair of their aneurysm. The cost-effectiveness systematic review identified six published decision models. Both models considered relevant for the decision in the UK concluded that EVAR was not cost-effective on average compared with open repair at a threshold of 20,000 pounds per quality-adjusted life-year (QALY). Another model concluded that EVAR would be on average more cost-effective than no surgical intervention in unfit patients at this threshold. The Medtronic model concluded that EVAR was more cost-effective than open repair for fit patients at this threshold. The York economic evaluations found that EVAR is not cost-effective compared with open repair on average at a threshold of 30,000 pounds per QALY, with the results very sensitive to model assumptions and the baseline risk of operative mortality. Exploratory analysis to evaluate management options in patients unsuitable for open surgery suggested that the cost-effectiveness of EVAR may be sensitive to aneurysm size and patient's age at operation. Indicative modelling suggests that EVAR may be cost-effective for small aneurysms in some patient groups. Ongoing RCTs will provide further evidence relating to these patients.

Conclusion

Open repair is more likely to be cost-effective than EVAR on average in patients considered fit for open surgery. EVAR is likely to be more cost-effective than open repair for a subgroup of patients at higher risk of operative mortality. These results are based on extrapolation of mid-term results of clinical trials. Evidence does not currently support EVAR for the treatment of ruptured aneurysms. Further follow-up of the existing UK trials should be undertaken and the relative costs of procedures and devices should be investigated further.

Share this page
Publication updates

If you would like to receive information on publications and the latest news, click below to sign up.