The Journal of Cardiovascular Surgery 2020 Nov 13

DOI: 10.23736/S0021-9509.20.11065-6

Copyright © 2020 EDIZIONI MINERVA MEDICA

language: English

Ascending aortic elongation and longitudinal strain: a comparison between ascending aortic aneurysms and healthy aortas

Sona HARBISH ✉

Department of Cardiac Surgery and Radiology, University Hospital Brussels, Brussels, Belgium

BACKGROUND: Growth of diameter fails to explain the transversal direction of ascending aortic dissection. Using 3D dynamic imaging, ascending aortic diameters, lengths, angles, and strain were measured for each type of ascending aneurysm to assess their role in aortic dissection and to better understand the pathogenesis of the disease.
METHODS: A non-interventional retrospective design study of ECG-gated CT-scans of aneurysm patients (n=101) compared with healthy controls (n=83) was performed. The aneurysm patients were divided in three subgroups; aortic root dilatation (Group Root), tubular dilatation (Group Tub), and aortic root and tubular dilatation (Group Root + Tub). The diameters, lengths and angles of the ascending aorta were measured using a self-developed measurement method within commercially available 3Mensio-software.
RESULTS: Median ascending aortic length of Group Root + Tub (112mm) and Group Tub (100.3mm) were significantly higher compared to Group Root (95.3mm) and the control group (87.7mm). Elongation mainly takes place at the outer curvature of the ascending aorta, and is associated with an increased angulation of the aortic root and a more curved ascending aorta. Ascending aortic dilatation is strongly associated with elongation. There was a significant decrease of longitudinal strain in Group Tub compared with the controls (a 47% decrease). Group Root + Tub and Group Root had a nonsignificant decrease of longitudinal strain (38% vs 12% decrease) compared with healthy aortas.
CONCLUSIONS: Aortic elongation and dilatation coincide and are strongly correlated. Elongation was significantly present in patients with tubular and whole ascending aortic aneurysms. Furthermore, elongation was associated with geometrical changes of the ascending aorta. Longitudinal strain in patients with ascending aortic aneurysms were decreased, offering a hypothetic mechanism for transverse aortic dissection or rupture. These findings may yield insight into the pathogenesis of ascending aortic aneurysm dissection.

KEY WORDS: Aorta; Aortic elongation; Aneurysm; Longitudinal strain; ECG-gated CT