Outcome of endovascular repair of small and large abdominal aortic aneurysms.

BACKGROUND

To evaluate the outcomes of endovascular aneurysm repair (EVAR) in patients with small (≤5.4 cm) and large (≥5.5 cm) abdominal aortic aneurysms (AAAs).

METHOD

Data for this study were obtained from the prospective, nonrandomized, multicenter Talent enhanced Low Profile Stent trial that enrolled patients between February 2002 and April 2003. A total of 156 patients with adequate preoperative imaging were identified for this study. Subgroup analyses were performed for patients with small (≤5.4 cm) and large (≥5.5 cm) AAAs. Demographics, aneurysm morphology, and perioperative endpoints were assessed. Safety and effectiveness endpoints were evaluated at 30 days, 1 year, and 5 years postprocedure.

RESULTS

Patients with small AAAs (n = 85) had similar age, gender, and medical risk profile compared with those for larger AAAs (n = 71). The proximal aortic necks in small AAAs were longer (24.7 mm vs. 20.7 mm, p = 0.05), less angulated (27.2° vs. 34.2°, p = 0.01), and smaller (24.6 mm vs. 26.1 mm, p = 0.01). Patients with small AAAs spent less time in intensive care (8.1 hour vs. 26.3 hour, p = 0.03); however, other perioperative endpoints were similar. Although the group with small AAAs had a statistically significant higher rate of successful aneurysm treatment (96.8% vs. 84.9%, p = 0.04), no difference was observed in all other effectiveness endpoints at 12 months. No differences in freedom from major adverse events at 30 days and 365 days were reported. At 5 years, no differences in rates of migration, endoleaks, change in aneurysm diameter, or freedom from aneurysm-related mortality were found. Further subgroup analyses segregating patients with very small (≤5.0 cm, n = 55), small (5.1-5.4 cm, n = 30), and larger (≥5.5 cm) AAAs also showed no statistically significant differences in postoperative outcomes.

CONCLUSIONS

In a prospective clinical trial setting with long-term follow-up, patients with small (≤5.4 cm) AAAs had aortic neck characteristics which were more favorable for EVAR. Despite these anatomic differences, clinical outcomes were similar to patients with large AAAs. Thus, we conclude that EVAR for small AAA should not be routinely recommended for patients on the basis of the assumption of improved outcomes.