Elsevier

The Lancet

Volume 365, Issue 9478, 25 June–1 July 2005, Pages 2187-2192
The Lancet

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Endovascular aneurysm repair and outcome in patients unfit for open repair of abdominal aortic aneurysm (EVAR trial 2): randomised controlled trial

https://doi.org/10.1016/S0140-6736(05)66628-7Get rights and content

Summary

Background

Endovascular aneurysm repair (EVAR) to exclude abdominal aortic aneurysm (AAA) was introduced for patients of poor health status considered unfit for major surgery. We instigated EVAR trial 2 to identify whether EVAR improves survival compared with no intervention in patients unfit for open repair of aortic aneurysm.

Methods

We did a randomised controlled trial of 338 patients aged 60 years or older who had aneurysms of at least 5·5 cm in diameter and who had been referred to one of 31 hospitals in the UK. We assigned patients to receive either EVAR (n=166) or no intervention (n=172). Our primary endpoint was all-cause mortality, with secondary endpoints of aneurysm-related mortality, health-related quality of life (HRQL), postoperative complications, and hospital costs. Analyses were by intention to treat.

Findings

197 patients underwent aneurysm repair (47 assigned no intervention) and 80% of patients adhered to protocol. The 30-day operative mortality in the EVAR group was 9% (13 of 150, 95% CI 5–15) and the no intervention group had a rupture rate of 9·0 per 100 person years (95% CI 6·0–13·5). By end of follow up 142 patients had died, 42 of aneurysm-related factors; overall mortality after 4 years was 64%. There was no significant difference between the EVAR group and the no intervention group for all-cause mortality (hazard ratio 1·21, 95% CI 0·87–1·69, p=0·25). There was no difference in aneurysm-related mortality. The mean hospital costs per patient over 4 years were UK£13 632 in the EVAR group and £4983 in the no intervention group (mean difference £8649, SE 1248), with no difference in HRQL scores.

Interpretation

EVAR had a considerable 30-day operative mortality in patients already unfit for open repair of their aneurysm. EVAR did not improve survival over no intervention and was associated with a need for continued surveillance and reinterventions, at substantially increased cost. Ongoing follow-up and improved fitness of these patients is a priority.

Introduction

The natural history of large abdominal aortic aneurysm (AAA) is progressive enlargement that can lead to rupture.1 The risk of rupture can be as high as 25% per year for aneurysms with diameters greater than 6 cm.2 Although open surgical repair3 is a tried and tested procedure for patients considered fit enough to withstand major surgery, the best way to manage unfit patients with large AAA, for whom the survival rate at 2 years can be as low as 50% (unpublished data from UK Small Aneurysm Study, UK Small Aneurysm Study Participants, Imperial College, London, UK), remains unclear. Endovascular aneurysm repair (EVAR), a minimally invasive approach, was developed as a possible solution.4, 5 As the technology developed, EVAR has been used increasingly in patients judged fit for open repair, and results of trials6, 7 show that the 30-day mortality in such patients is less than 2%. Although registry data8 suggest that 30-day mortality with EVAR is higher in unfit patients, the original use of the technique for unfit patients has not been rigorously examined.

The hypothesis underlying EVAR trial 2 was that, for unfit patients with an AAA of at least 5·5 cm in diameter, EVAR compared with no intervention would reduce the risk of aneurysm-related death from rupture and improve long-term survival and health-related quality of life (HRQL).

Section snippets

Patients and procedures

Between September, 1999, and December, 2003, we enrolled patients into a randomised controlled trial of individuals aged 60 years or older who had an aneurysm of at least 5·5 cm in diameter. We followed up all patients until Dec 31, 2004. Detailed methods for EVAR trial 2 have been described elsewhere.9, 10 The enrolment protocol and data collection methods are identical to those described for EVAR trial 1.10 Patients were recruited from 31 of 41 eligible hospitals. We regarded hospitals as

Results

Figure 1 shows the trial profile. Between September, 1999, and December, 2003, we identified 457 patients with an aneurysm of 5·5 cm in diameter or greater who were judged unfit for open repair.10 The characteristics of the 119 patients who refused to be randomised (mean age 77 years [SD 7], 86% male, median AAA diameter 6·5 cm [IQR 6·0–7·5]) did not differ from those of the patients who consented to randomisation (table 1). Patients who refused had a preference for EVAR (n=60), no intervention

Discussion

Our findings indicate that the patients we enrolled had significantly worse health than those studied in EVAR trial 1,6, 10 and show that EVAR is not a safe procedure in such high-risk patients. Concern remains about the medical treatment of these patients, since so few receive statins, which improve survival in patients with aneurysms.11, 12 The rupture rate we noted in the no intervention group, in patients with favourable anatomy in terms of neck dimensions and iliac involvement, is

References (13)

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Trial participants listed at end of EVAR trial 110

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