Aortic neck angulation predicts adverse outcome with endovascular abdominal aortic aneurysm repair

Significant aortic neck angulation may predispose to suboptimal outcome after endovascular abdominal aortic aneurysm (EAAA) repair. However, the definition of "significant" neck angulation and its correlation with adverse outcome are poorly characterized.

Prospectively collected data on 148 consecutive EAAA repairs performed between December 1995 and January 2001 were supplemented with retrospective review of charts and radiographs. Aortic neck angulation was measured from arteriograms or three-dimensional computed tomography scanning reconstructions. Patients were excluded (n = 24) if radiographs were unavailable for review. Because of a paucity of severe aortic neck angulation in other endograft groups, only patients treated with a modular bifurcated device (Medtronic) (n = 81) were included in the final analysis. Mean time from implantation was 26.6 +/- 9.2 months.

The risk of a patient experiencing one or more adverse events was 70%, 54.5%, and 16.6% in those with severe (>or=60 degrees, n = 10), moderate (40 to 59 degrees, n = 11), and mild (<40 degrees, n = 60) aortic neck angulation, respectively (P =.0003). Adverse events included death within 30 days (20% vs 0%, P =.0007), acute conversion to open repair (20% vs 0%, P =.0007), aneurysm expansion (9.1% to 20% vs 1.7%, P =.034), device migration (20% to 30% vs 3.3%, P =.013), and type I endoleak (23.8% vs 8.3%, P =.033), all occurring with significantly greater incidence in patients with moderate or severe aortic neck angulation when compared with those with mild angulation, respectively. Aortic neck length and diameter, age, and medical comorbidities were not significantly different between groups.

Aortic neck angulation appears to be an important determinant of outcome after EAAA repair. Although patients with mild angulation (<40 degrees) had favorable outcomes in this series, those with moderate (40 to 59 degrees) or severe angulation (>or=60 degrees) had a 54% to 70% risk of one or more adverse events. Importantly, these outcomes occurred in spite of an adequate length (>2 cm) of proximal aortic neck. On the basis of these data, great caution should be exercised in recommending EAAA repair for patients with aortic neck angulation >or=40 degrees.