Profiling abdominal aortic aneurysm growth with three-dimensional ultrasound.

Abstract

Profiling is a new method based on three-dimensional ultrasound (3D-US) allowing for direct comparison of baseline and follow-up diameters along the AAA length. This study aimed to evaluate the feasibility of profiling to visualize AAA changes at submaximum diameters, and to categorize the growth profiles. This is a retrospective analysis of prospectively and consecutively included patients under AAA surveillance at a tertiary referral center. 3D-US images of AAAs at baseline and at one-year follow-up were segmented, generating a centerline and a mesh of the aneurysm geometry. The mesh was processed to illustrate diameter changes of a given AAA. Three growth profiles were identified: 1) peak growth (the largest, significant [≥3.6 mm] diameter difference occurred within a 10 mm margin to either side of the maximum baseline diameter); B) edge growth (at least one significant diameter difference and the criteria for peak growth did not apply); and 3) no growth (all diameter differences were nonsignificant). A centerline length of ≥60 mm was assumed to capture a comparable segment of the wall geometry at baseline and follow-up. Cohen's kappa and Kaplan Meier analysis were used to analyze data. In total, 186 patients had growth profiles generated. Of these, 28 (15%) were discarded, mainly based on inadequate centerline lengths (N.=21, 11.3%). The remaining patients were categorized into edge growth (N.=83, 52%), no growth (N.=47, 30%), and peak growth (N.=28, 18%). Profiling interprets AAA growth at submaximum diameters. Half of the cohort had edge growth. These AAAs risk being classified as stable.