Small infrarenal abdominal aortic aneurysms have a more favorable clinical and morphologic outcome compared with medium and large abdominal aortic aneurysms following endovascular aneurysm repair(EVAR).
A prospective clinical series of 206 patients undergoing elective EVAR between 1996 and 2001.
A tertiary care academic health center.
Patients were grouped according to aneurysm size: small (<50 mm), medium (50-60 mm), and large (>60 mm).
Primary EVAR and secondary procedures to secure fixation of the stent graft and surgical conversions.
Main Outcome Measures
Aneurysm diameter, endoleaks, and long-term morphologic changes were analyzed postoperatively with 3-dimensional reconstructions of computed tomographic angiograms.
Groups were similar in age, comorbidities, and follow-up (mean ± SD, 32.1 ± 11.8 months). There were 30 small aneurysms, 92 medium aneurysms, and 84 large aneurysms, with a mean size of 45.1 ± 3.7 mm, 53.8 ± 3.1 mm, and 66.1 ± 6.8 mm, respectively (P<.01). There was no significant difference in proximal neck or iliac artery diameter among the 3 groups. The proximal aortic neck length (28.1 ± 11.6 mm [small]; 23.9 ± 11.3 mm [medium]; and 22.1 ± 11.6 mm [large]; P<.05) was significantly shorter in large aneurysms. Furthermore, there was a significant increase (6% [small]; 15% [medium]; and 21% [large]; P<.05) in angulated necks in large aneurysms. Following treatment, aneurysm diameter remained stable in most patients (83% [small]; 82% [medium]; and 83% [large]), with a mean decrease of 2.0 ± 6.5 mm, 2.1 ± 6.1 mm, and 3.7 ± 7.7 mm in each group, respectively (P = .45). There was no difference in the incidence of endoleaks, aneurysm contraction, or aneurysm expansion based on preoperative aneurysm diameter. Secondary procedures were performed in 5 (20%) of 25, 9 (5.2%) of 170, and 5 (36%) of 11 aneurysms that contracted, remained stable, or expanded, respectively, following EVAR (P<.05).
There is a 15% increase in neck angulation and a 27% decrease in neck length in large compared with small infrarenal abdominal aortic aneurysms, with no difference in outcome. Aneurysms that are stable following EVAR have a significantly lower incidence of requiring secondary procedures.