Aneurysm Detection and Management Veterans Affairs Cooperative Study - ADAM

Description:

The Aneurysm Detection and Management Veterans Affairs Cooperative Study (ADAM) was a randomized clinical trial designed to determine which of two strategies would result in a higher rate of survival for patients with small (4.0-5.4 cm) abdominal aortic aneurysm: immediate open surgical repair or surveillance with ultrasonography, or computed tomography (CT) with repair reserved for aneurysms that enlarged or became symptomatic.

Hypothesis:

Whether elective surgical repair of small abdominal aortic aneurysms improves survival remains controversial.

Study Design

Study Design:

Patients Screened: 126,196
Patients Enrolled: 1,136
Mean Follow Up: Mean 4.9 years
Female: 1

Patient Populations:

Eligible patients were 50 to 79 years of age and had abdominal aortic aneurysms that measured 4.0-5.4 cm in diameter by CT within 12 weeks before randomization.

Exclusions:

Previous aortic surgery; evidence of rupture; expansion of the aneurysm of 1.0 cm or more in the past year, or 0.7 cm or more in the last six months; suprarenal or juxtarenal aneurysm (defined by an anticipated need for reimplantation of a main renal artery); a known thoracic aneurysm of 4.0 cm or more in diameter; a probable need for aortic surgery within six months, other than repair of the aneurysm; severe heart, lung, or liver disease; a serum creatinine concentration of 2.5 mg/dl or higher; a history of a major surgical procedure or angioplasty within the previous three months; expected survival of less than five years; severe debilitation; an inability to give informed consent; or a high likelihood of noncompliance with the protocol

Primary Endpoints:

Rate of death from any cause

Secondary Endpoints:

Rate of death related to abdominal aortic aneurysm, defined as death caused directly or indirectly by rupture or repair, preoperative evaluation, late graft failure or complication, or abdominal aortic aneurysm or pseudoaneurysm after grafting or any death occurring within 30 days after aneurysm repair (including reoperations) or within 30 days after randomization in patients in the surveillance group

Drug/Procedures Used:

Patients were randomly assigned either to immediate surgical repair or to surveillance with ultrasonography or CT (every six months), with repair reserved for aneurysms that enlarged until they reached at least 5.5 cm in diameter, or enlarged by at least 0.7 cm in six months, or at least 1.0 cm in one year, or became symptomatic. Follow-up ranged from 3.5 to 8.0 years (mean 4.9 years).

Concomitant Medications:

N/A

Principal Findings:

A total of 569 patients were randomly assigned to immediate repair, and 567 to surveillance. By the end of the study, aneurysm repair had been performed in 92.6% of the patients in the immediate repair group and 61.6% of those in the surveillance group. The rate of death from any cause, the primary outcome, was not significantly different in the groups (relative risk in the immediate repair group as compared to the surveillance group, 1.21; 95% confidence interval 0.95-1.54). These findings were obtained despite a low total operative mortality of 2.7% in the immediate repair group.

There was also no reduction in the rate of death related to abdominal aortic aneurysm in the immediate repair group (3.0%) as compared with the surveillance group (2.6%). Eleven patients in the surveillance group had rupture of abdominal aortic aneurysms (0.6% per year), resulting in seven deaths. The rate of hospitalization related to abdominal aortic aneurysm was 39% lower in the surveillance group.

Interpretation:

Among patients with abdominal aortic aneurysms smaller than 5.5 cm, survival is not improved by elective repair of the aneurysm. Whether the results of this trial would apply to practice settings with less rigorous surveillance programs is not known.

References:

Lederle FA, Wilson SE, Johnson GR, et al., for the Aneurysm Detection and Management Veterans Affairs Cooperative Study Group. Immediate repair compared with surveillance of small abdominal aortic aneurysms. N Engl J Med 2002;346:1437-44.

Clinical Topics: Noninvasive Imaging, Vascular Medicine, Computed Tomography, Nuclear Imaging

Keywords: Surgical Procedures, Elective, Tomography, X-Ray Computed, Aortic Aneurysm, Abdominal, Hospitalization


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