Title: Elective Endovascular Abdominal Aortic Aneurism Repair versus Open Surgery: A Clinical and Cost Effectiveness Review

Transcription

1 Title: Elective Endovascular Abdominal Aortic Aneurism Repair versus Open Surgery: A Clinical and Cost Effectiveness Review Date: 07 April 2008 Context and policy issues: Abdominal aortic aneurism (AAA) occurs in 5% of men and 1% of women over the age of 65 years, and the rupture of an AAA is a significant cause of death. 1 Elective repair of AAA (repair of a non-ruptured aneurism) by a conventional open surgical approach has reasonable longterm survival, but it carries a high risk to older patients or those with comorbidities such as cardiovascular or pulmonary conditions. 2 In contrast to open surgery, endovascular AAA repair (EVAR) is a catheter-based procedure that does not require an abdominal incision or dissection and clamping of the aorta. 3,4 In Canada, the development of the endovascular program at London Health Sciences Centre has experienced a doubling of elective aneurism cases during 1997 to 2003, with elective EVARs constituting 28% of the entire elective AAA repairs. 5 Because of the increased trend of EVAR and its high cost, this bulletin is looking at the clinical and cost effectiveness of elective EVAR as compared to open surgery repair. Research questions: 1. What is the clinical effectiveness of elective EVAR compared to open repair for AAA? 2. Is there any evidence that elective EVAR is more effective for larger aneurisms? 3. What is the cost effectiveness of elective EVAR compared to open repair for AAA? Methods: A limited literature search was conducted on key health technology assessment resources, including PubMed, The Cochrane Library (Issue 1, 2008), University of York Centre for Reviews and Dissemination (CRD) databases, ECRI, EuroScan, international HTA agencies, and a Disclaimer: The Health Technology Inquiry Service (HTIS) is an information service for those involved in planning and providing health care in Canada. HTIS responses are based on a limited literature search and are not comprehensive, systematic reviews. The intent is to provide a list of sources and a summary of the best evidence on the topic that CADTH could identify using all reasonable efforts within the time allowed. HTIS responses should be considered along with other types of information and health care considerations. The information included in this response is not intended to replace professional medical advice, nor should it be construed as a recommendation for or against the use of a particular health technology. Readers are also cautioned that a lack of good quality evidence does not necessarily mean a lack of effectiveness particularly in the case of new and emerging health technologies, for which little information can be found, but which may in future prove to be effective. While CADTH has taken care in the preparation of the report to ensure that its contents are accurate, complete and up to date, CADTH does not make any guarantee to that effect. CADTH is not liable for any loss or damages resulting from use of the information in the report. Copyright: This report contains CADTH copyright material. It may be copied and used for non-commercial purposes, provided that attribution is given to CADTH. Links: This report may contain links to other information on available on the websites of third parties on the Internet. CADTH does not have control over the content of such sites. Use of third party sites is governed by the owners own terms and conditions.

2 focused Internet search. Results include articles published between 2003 and March 2008, and are limited to English language publications only. Filters were applied to limit the retrieval to systematic reviews/health technology assessments, randomized controlled trials (RCTs) and economic studies. Summary of findings: Clinical effectiveness of EVAR A rigorous meta-analysis with a systematic literature search from 1966 through 2006 included two RCTs comparing elective open repair to surveillance for small AAAs (< 5.5 cm) in 2226 patients, and four RCTs that compared elective EVAR versus open repair for large AAAs ( 5.5cm) in 1532 patients. 6 Elective open repair for AAAs smaller than 5.5 cm has not been shown to cause any statistically significant difference in all-cause mortality (relative risk 1.01 [CI 0.77 to 1.32]) or AAA-related mortality (relative risk 0.78 [CI 0.56 to 1.10]) as compared to surveillance. On the other hand, for large AAAs, EVAR reduced 30-day all-cause mortality (relative risk 0.33; CI 0.17 to 0.64) but not mid-term (up to 4 years) mortality (relative risk 0.95; CI 0.76 to 1.19). Each trial found a significant reduction in length of hospital stay with EVAR compared to open repair (6.2 days vs days). A small prospective trial in also agreed with the systematic review and found that the 30-day mortality was reduced with EVAR. Cost-effectiveness of EVAR A systematic review of economic studies published between 1999 and 2005 reporting the cost and/or cost-effectiveness of elective EVAR and/or open surgery of non-ruptured AAAs included three RCTs, 12 case series, four Markov models, and one systematic review. 8 All studies found that EVAR costs more than open surgery. For patients with AAA < 5.5cm, immediate open surgery costs more than active surveillance with selective open surgery with no improvement in survival. Among patients with AAA 5.5cm, EVAR has greater short and long term costs with no improvement in overall survival or quality of life beyond one year. A recent randomized trial compared the cost-effectiveness of elective EVAR and open repair in 351 patients in The Netherlands. 9 EVAR was associated with additional 4293 direct costs ( 18,179 vs 13,866; CI 2770 to 5830). Routine use of elective EVAR in patients also eligible for open repair does not result in a quality adjusted life-year (QALY) gain at one year postoperatively, provides only a marginal overall survival benefit, and is associated with a substantial increase in costs. A decision model to estimate the lifetime costs in UK and QALYs with elective EVAR and open repairs was constructed. 10 EVAR costs 3,800 (CI 2,400 to 5,200) more per patient than open repair but produced fewer lifetime QALYs. EVAR for repair of ruptured AAA In addition to elective repair, clinical effectiveness of emergency repair of AAA (repair of a ruptured aneurism) by EVAR versus open surgery was also the focus of many clinical trials which were reviewed in a recent systematic review and meta-analysis 8 that covered publications from 1994 to Emergency EVAR was associated with a statistically significant reduction in 30-day mortality, intensive care unit stay, hospital stay, blood loss and operative time compared to open surgery. A Cochrane review 11 that covered trials until 2006 on the same topic also found similar results. It is important to note that none of the included trials in either of the two EVAR versus Open Surgery 2

3 systematic reviews is a RCT, which leads to caution in interpretation of the findings. Two small cost-effectiveness studies comparing emergency EVAR to emergency open repair were found. 12,13 A preferential emergency EVAR protocol for ruptured AAAs can decrease mortality but does not increase overall direct medical costs as compared to emergency open repair-only protocol. 12 When one-year follow-up costs were added to total in-hospital costs, the costs were lower with emergency EVAR than emergency open repair. 13 Conclusions and implications for decision making: Despite a reduction in short term mortality in patients with aneurisms 5.5 cm, elective EVAR does not appear to improve overall survival beyond one year, and is unlikely to be cost-effective on the basis of existing devices, costs and evidence. No difference in mortality was seen with aneurisms < 5 cm with EVAR compared to open surgery. Caution should be made before the widespread use of elective EVAR. Emergency EVAR also showed a short term clinical benefit, and appears to be cost-effective, but higher quality trials are needed to consolidate the findings. Prepared by: Chuong Ho, MD, MSc, Research Officer Carolyn Spry, MLIS, Information Specialist Health Technology Inquiry Service htis@cadth.ca Tel: EVAR versus Open Surgery 3

4 References: 1. Kamineni R, Heuser RR. Abdominal aortic aneurysm: a review of endoluminal treatment. J Interv Cardiol 2004;17(6): Brewster DC, Cronenwett JL, Hallett JW, Johnston KW, Krupski WC, Matsumura JS. Guidelines for the treatment of abdominal aortic aneurysms. Report of a subcommittee of the Joint Council of the American Association for Vascular Surgery and Society for Vascular Surgery. J Vasc Surg 2003;37(5): Lindsay TF. Canadian Society for Vascular Surgery consensus statement on endovascular aneurysm repair. CMAJ 2005;172(7): Available: (accessed 2008 Mar 19). 4. Rose J. Stent-grafts for unruptured abdominal aortic aneurysms: current status. Cardiovasc Intervent Radiol 2006;29(3): Forbes TL, Lawlor DK, DeRose G, Harris KA. Examination of the trend in Canada toward geographic centralization of aneurysm surgery during the endovascular era. Ann Vasc Surg 2006;20(1): Lederle FA, Kane RL, MacDonald R, Wilt TJ. Systematic review: repair of unruptured abdominal aortic aneurysm. Ann Intern Med 2007;146(10): Available: (accessed 2008 Mar 25). 7. Fotis T, Tsoumakidou G, Katostaras T, Kalokairinou A, Konstantinou E, Kiki V, et al. Cost and effectiveness comparison of endovascular aneurysm repair versus open surgical repair of abdominal aortic aneurysm: a single-center experience. J Vasc Nurs 2008;26(1): Jonk YC, Kane RL, Lederle FA, MacDonald R, Cutting AH, Wilt TJ. Cost-effectiveness of abdominal aortic aneurysm repair: a systematic review. Int J Technol Assess Health Care 2007;23(2): Prinssen M, Buskens E, de Jong SE, Buth J, Mackaay AJ, Van Sambeek MR, et al. Cost-effectiveness of conventional and endovascular repair of abdominal aortic aneurysms: results of a randomized trial. J Vasc Surg 2007;46(5): Epstein DM, Sculpher MJ, Manca A, Michaels J, Thompson SG, Brown LC, et al. Modelling the long-term cost-effectiveness of endovascular or open repair for abdominal aortic aneurysm. Br J Surg 2008;95(2): Dillon M, Cardwell C, Blair PH, Ellis P, Kee F, Harkin DW. Endovascular treatment for ruptured abdominal aortic aneurysm [Cochrane review]. Cochrane Database Syst Rev 2007;(1):CD Kapma MR, Groen H, Oranen BI, van der Hilst CS, Tielliu IF, Zeebregts CJ, et al. Emergency abdominal aortic aneurysm repair with a preferential endovascular strategy: mortality and cost-effectiveness analysis. J Endovasc Ther 2007;14(6): EVAR versus Open Surgery 4

5 13. Visser JJ, Van Sambeek MR, Hunink MG, Redekop WK, Van Dijk LC, Hendriks JM, et al. Acute abdominal aortic aneurysms: cost analysis of endovascular repair and open surgery in hemodynamically stable patients with 1-year follow-up. Radiology 2006;240(3): EVAR versus Open Surgery 5