Long-term outcome of open or endovascular repair of abdominal aortic aneurysm
Authors: Joseph Philip 
Published: December 2010

Study objective: To evaluate long-term outcomes of endovascular or open abdominal aortic aneurysm (AAA) repair in patients who were enrolled in the Dutch Randomized Endovascular Aneurysm Repair (DREAM) study.

Study population: Patients were eligible for DREAM if they had an AAA measuring at least 50 mm in diameter, and were considered candidates for either mode of repair. Patients were excluded if they required emergency aneurysm repair, had inflammatory aneurysms, anatomic variations precluding repair, connective tissue disease, previous organ transplantation or a life expectancy of less than 2 years. Suitability for endovascular repair was primarily based on anatomic criteria. Patients were deemed suitable for open repair based on the opinion of a cardiologist or internist.

Design and methods: This study is a secondary analysis of long-term outcomes of patients enrolled in the DREAM study, a multi-centered, randomized, clinical trial. Randomization initially occurred in a 1:1 ratio via computer algorithm, and was stratified according to center in a permuted-block sequence of four patients. While the original analysis of DREAM examined short-term mortality and complications, the primary outcomes outlined in this analysis were long-term death from any cause and the need for repeat intervention. A reintervention was defined as a repeat procedure related to the initial repair secondary to a graft (e.g. prosthesis infection or type 1 endoleak), wound (e.g. incisional hernia or wound infection), or local or systemic complication. The primary analysis was intention to treat. After the second year of enrollment, patients received biannual questionnaires evaluating physical health and utilization of medical resources, with additional data collected based on routine clinical care. At the conclusion of the study period, follow-up was attempted on all patients either directly, or through their relatives or physicians.

Results: The DREAM study randomly enrolled 178 patients to undergo open repair and 173 patients to undergo endovascular repair. Data collection for this analysis was stopped after a mean follow-up of 6.4 years (CI: 5.1 to 8.2). Baseline characteristics were similar in both groups regarding associated cardiac disease and cardiovascular risk factors. Long-term follow-up was high in both the open repair group (99.3%) and endovascular group (99.7%). At the conclusion of the study, overall survival rates were 69.9% in the open repair group and 68.9% in the endovascular group ( p = 0.97, 95% confidence interval (CI): —8.8 to 10.8). Freedom from reintervention was significantly higher in the open repair group compared to the endovascular group (81.9% vs 70.4%, p = 0.03; 95% CI: 2.0 to 21.0). The most common cause for reintervention in the endovascular group was endograft related (75.0%). Patients in the open group most commonly underwent reintervention for an incisional hernia (46.7%).

Conclusions: Endovascular and open repair for AAA have similar survival outcomes at 6 years. There is an increased rate of reintervention associated with endovascular repair, primarily due to graft-related complications.