ARTORG Center for Biomedical Engineering Research


2024/01/10 | Research | Biomechanics

Aortic root geometry might influence artificial valve thrombosis

Together with the Department of Cardiology at Inselspital the Cardiovascular Engineering group has performed a pilot study suggesting a direct effect of the aortic dimensions on clinically apparent transcatheter heart valve thrombosis (THVT). The team studied fluid-structure interaction in two idealized aortic models, simulating different diameters for the sinotubular junction and ascending aorta.

The average velocity field from the computational analysis in the (a) control and (b) the THVT aortic models, seen from two different views normal to the main flow direction, and for three perpendicular cross sections at (1) the sinotubular junction, (2) in the ascending aorta and (3) in the bend toward the aortic arch. (

The etiology of transcatheter heart valve thrombosis (THVT) and the relevance of the aortic root geometry on the occurrence of THVT are largely unknown. This pilot study aimed to identify differences in aortic root geometry between THVT patients and patients without THVT after transcatheter aortic valve implantation (TAVI) as well as to investigate how the observed difference in aortic diameters affects the aortic flow.

Using aortic dimensions from 8 patients with clinical apparent THVT and 16 unaffected patients from the Bern-TAVI registry, the study found the diameters of the observed structures to be larger by 9 and 14% repectively, leading to a higher backflow rate, lower velocity and higher systolic turbulence. The fluid-structure study indicated that larger sinotubular junction and ascending aorta diameters potentially favor thrombus formation. Hence, further clinical validation could potentially help identifying patients at risk for THVT.