This review concluded that endovascular aortic aneurysm repair carried a threefold lower risk of perioperative death in comparison to open repair. The review had some limitations (mainly related to reporting), but overall appears to be reliable.

To evaluate the effectiveness of endovascular aortic aneurysm repair (EVAR) in reducing perioperative mortality when compared to open repair

The authors searched MEDLINE, EMBASE, CINAHL and The Cochrane Library for studies published in any language between January 1996 and December 2007. Search terms were documented in the article. They reviewed Current Contents and other relevant electronic databases (unspecified) and carried out handsearches and reference checking.

Included studies needed to be randomised controlled trials (RCTs) of EVAR versus open abdominal aortic aneurysm repair with patients of any age and sex. The main outcome was perioperative mortality; this was not defined explicitly and definitions used in the included trials were not reported. Two authors assessed study eligibility.

The quality of trials was assessed using 10 criteria, including (but not restricted to) blinding, randomisation technique and analysis by intention to treat.

The authors did not state how the validity assessment was performed.

Risk ratios were calculated from numbers of deaths in each group.

The authors did not state how many reviewers performed the data extraction.

Both fixed-effect and random-effects meta-analyses were conducted. Heterogeneity was assessed using Cochran's Q test.

Three RCTs were included in the review (n=1,468). The methodological quality of all three was found to be adequate.

EVAR was associated with statistically significantly lower perioperative mortality when compared to open repair. The fixed-effect model gave a risk ratio of 0.33 (95% CI 0.17 to 0.65, p<0.001) and the random-effects model gave a risk ratio of 0.23 (95% CI 0.12 to 0.43, p=0.0001). There was no evidence of heterogeneity between the trials.

EVAR carried a threefold lower risk of perioperative death in comparison to open repair of abdominal aortic aneurysms.

Inclusion criteria for this review were defined in terms of patient, intervention, outcome and study design. The authors provided no definition of perioperative mortality, which might have varied between trials. Searching encompassed a range of resources. Study quality was assessed, but it was unclear if more than one reviewer was involved in this and the data extraction process to help minimise bias and error. Meta-analysis appeared to be appropriate, but fuller study details would have helped to highlight any clinical heterogeneity. Despite these problems (which appeared to be mainly related to reporting) the review appears to be reliable.

Practice: The authors stated that EVAR should be the treatment of choice for older and high operative risk patients, but a highly skilled and appropriately staffed vascular team with appropriate facilities was needed to carry out a successful EVAR.

Research: The authors stated that long-term assessment of secondary outcome measures such as re-intervention rate, cost-effectiveness and psychological impact on patients needed further investigation before EVAR was accepted as a standard treatment procedure.

Not stated.

Lederle F, Kane RL, MacDonald R, Wilt T. Systematic Review: Repair of Unruptured Abdominal Aortic Aneurysm. Ann Intern Med 2007; 146: 735-741

This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.