Assessment of the Aorto-Septal Angle Post-Thoracic Endovascular Aortic Repair through Segmentation and the Semi-Automatic Analysis of Cardiosynchronized Computed Tomography Angiography Images

Abstract

The aim of this study was to inviestigate cardiac and arterial remodelling before and after thoracic endovascular aortic repair (TEVAR) by measuring the Aorto-Septal Angle (AoSA) and the geometric characteristics of the aorta. Five patients were prospectively included. Pre- and post-operative cardio-CTA scans were used to create patient-specific 3D models to calculate the AoSA, defined by the intersection of the aortic and left ventricular axes. Additionally, geometric parameters and the inclination of the ascending aorta (AA) were measured. The results demonstrated a variation between pre- and post-operative AoSA in all patients, with an increase in the case of an aneurysmal disease from 112.36° ± 8.21° to 117.16° ± 9.65° (+4.1%, p = 0.041) and a decrease in the case of aortic dissection from 113.62° ± 0.96° to 107.83° ± 1.45° (−5.1%). Additionally, an increase in the length of both the outer and inner curvatures of the AA was observed from 102.21 ± 10.17 mm to 105.73 ± 11.2 mm (+ 3.33% p = 0.016) and from 55.55 ± 9.53 mm to 58.35 ± 9.96 mm (+4.8%, p = 0.04), respectively. This study introduced a new repeatable and reproducible method for assessing the AoSA using cardiac-CTA images. Thoracic stent deployment changes the AoSA, potentially impacting long-term left ventricle hemodynamics.

Keywords

• aorto-septal angle
• cardiac remodelling
• TEVAR
• thoracic aorta