The details of the Amsterdam Acute Aneurysm Trial (AJAX) study
| Methods | Study type: multicentre, randomised controlled trial, intention-to-treat Study aim: compare EVAR and open repair in treating RAAA on mortality and severe complications Country: The Netherlands Setting: three large hospital vascular centres in Amsterdam | |
| Participants | Number randomised: total n=116 (eEVAR n=57; open repair n=59) Age (mean years, 95% CI): eEVAR=74.5 (72.3 to 77.5); open repair=74.5 (72.2 to 76.8) Gender (M/F): eEVAR=49/8; open repair=50/9 Inclusion criteria: male and females over 18 years; clinical diagnosis of RAAA; aneurysm accompanied by acute haemorrhage outside of the aortic wall of CTA; suitable for eEVAR and open repair Exclusion criteria: extension of the aneurysm to juxtarenal or suprarenal aorta; kidney transplant; horseshoe kidney; allergy to intravenous contrast; connective tissue disease; severe haemodynamic instability prohibiting CT eEVAR anatomical suitability requirements: suitable infrarenal anchoring segment, minimum length of the infrarenal segment of at least 10–15 mm, infrarenal diameter of 20–32 mm, no obstructing calcifications, tortuosity of thrombosis, suitable iliac anchoring segment, ipsilateral iliac diameter of 8–18 mm, contralateral iliac diameter of 10–20 mm, at least one iliac artery should be able to accommodate an endograft CVD risk factors (n (%)): diabetes (EVAR n=2 (4%), open repair n=1 (2%)); hypertension (EVAR n=13 (23%), open repair n=10 (17%)); smoker (EVAR n=23 (40%), open repair n=20 (34%)); hyperlipidaemia (EVAR n=13 (23%), open repair n=19 (32%)); renal disease (EVAR n=1 (2%), open repair n=2 (3%)); pulmonary disease (EVAR n=7 (12%), open repair n=3 (5%)); carotid disease (EVAR n=16 (28%), open repair n=10 (17%)); cardiac disease (EVAR n=16 (28%), open repair n=14 (24%))Type of RAAA: infrarenal | |
| Interventions | eEVAR description: aortouniiliac endograft and contralateral iliac occluding device, followed by a femoro-femoral crossover bypass graft Open repair description: midline laparotomy and exclusion of rupture aneurysm by either polyester tube or bifurcated graft; conducted under general anaesthesia | |
| Outcomes | Composite death and severe complications at 30 days after intervention; long-term mortality rates (6 months after randomisation); length of hospital and ICU stay; duration of intubation/ventilation; use of blood products; for EVAR, occurrence of endoleaks | |
| Notes | Study period: April 2004 to February 2011; three main trial centres, all other (seven) regional hospitals transferred participants to one of the trial centres | |
| Risk of bias | ||
| Bias | Authors’ judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | ‘The randomization sequence was generated by an independent clinical research unit using ALEA software for randomization in clinical trials with a 1:1 allocation using random block sizes of 4 or 6, stratified for each participating centre’. |
| Allocation concealment (selection bias) | Low risk | ‘Allocation was concealed using sequentially numbered opaque sealed envelopes’. |
| Blinding of participants and personnel (performance bias); all outcomes | Low risk | Surgical team not possible to blind, but unlikely to influence outcomes |
| Blinding of outcome assessment (detection bias); all outcomes | Low risk | Double database entry; end point adjudication committee blinded; independent safety committee blinded |
| Incomplete outcome data (attrition bias); all outcomes | Low risk | All patients accounted for in CONSORT diagram; both treatment groups had similar dropout rates and reasons |
| Selective reporting (reporting bias) | Unclear risk | Although all predescribed outcomes listed in the Reimerink publication are reported, quality of life and cost-effectiveness as described in the study protocol, were not included, suggesting further publications to emerge |
| Other bias | Low risk | None |
CVD, cardiovascular disease; eEVAR, emergency endovascular aneurysm repair; F, female; ICU, intensive care unit; M, male; RAAA, ruptured abdominal aortic aneurysm.