Through-Plane Movement at Multiple Aortic Levels on Dynamic Computed Tomography Angiography Is Limited in Patients...

To analyze the movement of the aorta in the craniocaudal direction (through-plane movement) during the cardiac cycle at several levels to determine any potential impact on endovascular aneurysm repair (EVAR) of abdominal aortic aneurysm (AAA).

For this study, 30 patients (median age 73.0 years; 27 men) with an infrarenal AAA were randomly selected from a prospectively maintained EVAR database. All patients had undergone preoperative electrocardiogram-gated computed tomography angiography consisting of 8 phases. After semiautomatic segmentation, a 3-dimensional location probe was placed in the center of the aorta (center point) on the orthogonal slices at 12 different levels along the aorta and iliac arteries for all 8 phases. Movement of the center point during the cardiac cycle was analyzed for each level. Values are given as the median and interquartile range (IQR).

The median through-plane movement of all levels was 3.0 mm (IQR 2.8-3.2) and appeared to be lower in the region of the celiac and renal arteries: 2.6 mm (IQR 1.7-3.1) at 3 cm proximal to the most distal renal artery and 2.4 mm (IQR 1.9-2.9) at 1 cm distal to the most distal renal artery, respectively. The thoracic part of the aorta showed the largest through-plane motion: 4.1 mm (IQR 2.7-4.6).

This study quantifies aortic through-plane motion in the craniocaudal direction. Since through-plane movement appears to be limited, findings of previous studies investigating pulsatile in-plane distension seem to be representative for aortic distension.