Endovascular aneurysm repair in patients with a wide proximal aortic neck: a systematic review and meta-analysis of comparative studies.

INTRODUCTION: The aim was to investigate the impact of wide proximal aortic diameter on outcome after standard endovascular repair (sEVAR) of infrarenal abdominal aortic aneurysms.

EVIDENCE ACQUISITION: A systematic search of the literature was undertaken using the PUBMED, EMBASE, and Cochrane databases for articles comparing outcome after sEVAR in patients with large versus small diameter aortic neck. The prognostic factor of interest was large diameter proximal aortic neck and the results were reported as odds ratio (OR) or mean difference (MD) and 95% confidence interval (CI). A time-to-event data meta-analysis for late outcomes was performed using the inverse-variance method and reported the results as summary hazard ratio (HR) and 95% CI.

EVIDENCE SYNTHESIS: We identified 6 observational studies reporting on a total of 6602 patients (1616 with large and 4986 with small diameter neck). Patients with large proximal aortic neck were older (MD 0.87, 95% CI: 0.35-1.39; P=0.001). The prevalence of male gender (OR=1.63, 95% CI: 1.34-1.98; P<0.001), coronary artery disease (OR=1.20, 95% CI: 1.06-1.36; P=0.004), chronic obstructive pulmonary disease (OR=1.18, 95% CI: 1.03-1.36; P=0.02) and chronic kidney disease (OR=1.43, 95% CI: 1.23-1.66; P<0.001) was higher in the wide neck group. Patients with large diameter proximal neck had shorter proximal neck (MD=-1.91, 95% CI: -2.04 to -1.77; P<0.001) and a larger aneurysm diameter compared to those with small diameter neck (MD=3.40, 95% CI: 2.71-4.10; P<0.001). Patients with small diameter proximal neck had significantly higher freedom from aneurysm-related reintervention (HR=2.06, 95% CI: 1.23-3.45; P=0.006), freedom from type Ia endoleak (HR=6.69, 95% CI: 4.39-10.20; P<0.001), freedom from sac expansion (HR=10.07, 95% CI: 1.80-56.53; P=0.009), freedom from aneurysm rupture (HR 5.10, 95% CI: 1.40-18.58; P=0.01), and survival (HR=1.55, 95% CI: 1.08-2.24; P=0.02).

CONCLUSIONS: Patients with a wide proximal aortic neck undergoing standard EVAR were found to have worse outcome, as indicated by a lower freedom from aneurysm-related reintervention, type Ia endoleak, sac expansion and aneurysm rupture, and a higher overall survival. This anatomic characteristic should be considered in decision making. In such patients, closer imaging surveillance after EVAR in the long term may be required to identify early and treat timely the complications.