Three-dimensional ultrasound is a reliable alternative in endovascular aortic repair surveillance.

Abstract Objectives Three-dimensional ultrasound (3D-US) has already demonstrated improved reproducibility with a high degree of agreement (inter-modality variability), replicability (inter-operator variability) and repeatability (intra-operator variability) in comparison to conventional two-dimensional ultrasound (2D-US) when estimating maximum diameter of native abdominal aortic aneurysms (AAAs). The aim of this study was, in a clinical, multicentre setting, to evaluate the accuracy of 3D-US with aneurysm model quantification software (3D-US AAA model) for endovascular aneurysm repair (EVAR) sac diameter assessment, in comparison to computed tomographic angiography (CTA) and 2D-US. Material and Methods A total of 182 patients, who had undergone an EVAR procedure between April 2016 and December 2017, and compliant with the standardised EVAR surveillance programme, were enrolled from five different vascular centres (Rigshospitalet in Copenhagen, Denmark; Catharina Ziekenhuis in Eindhoven, Netherlands; L´hospital de la Timone in Paris, France; Cleveland Clinic in Cleveland, USA and The Christ Hospital in Cincinnati, USA), in four countries. All image acquisitions were performed at the local sites (2D-US, 3D-US and CTA). Only the 2D-US and CTA readings were performed both locally and centrally, otherwise all images were read centrally by the US and CTA core lab. Anonymized image data was read in a randomised and blinded manner. Results The sample estimating the accuracy of 3D-US AAA model consisted of 164 patients and for 2D-US 177 patients. According to Bland-Altman analysis, the mean difference between CTA and 3D-US was -2.43 mm (95%: -5.20, 0.14; p = 0.07) with lower and upper limits of agreement (LoA) of -8.9mm (95% CI: -9.3, -8.4) and 2.7mm (95% CI: 2.3, 3.2). For 2D-US and CTA the mean difference was -3.62 mm (95%: -6.14, -1.10; p=0.002), with lower and upper LoA of -10.3mm (95% CI: -10.8, -9.8) to 2.5mm (95% CI: 2, 2.9) Conclusions Three-dimensional ultrasound AAA model showed no significant difference compared with CTA for measuring AP diameter, indicating less 3D-US bias in comparison with 2D-US. Three-dimensional ultrasound with AAA model software is a viable modality for AP diameter assessment in EVAR surveillance.