Idealized aortic annuloplasty FSI digital twin of 3D-printed phantoms with 4D-flow MRI comparison

Luca Bontempi; Marta Zattoni; Anna Ramella; Francesco Migliavacca; Steffen Ringgaard; Won Yong Kim; Peter Johansen; Monika Colombo

doi:10.1016/j.compbiomed.2025.110398

Idealized aortic annuloplasty FSI digital twin of 3D-printed phantoms with 4D-flow MRI comparison

Comput Biol Med. 2025 Jun;192(Pt B):110398. doi: 10.1016/j.compbiomed.2025.110398. Epub 2025 May 18.

Authors

Luca Bontempi¹, Marta Zattoni², Anna Ramella³, Francesco Migliavacca³, Steffen Ringgaard⁴, Won Yong Kim⁵, Peter Johansen⁶, Monika Colombo⁷

Affiliations

¹ Department of Mechanical and Production Engineering, Aarhus University, Aarhus, Denmark; Laboratory of Biological Structure Mechanics (LaBS), Department of Chemistry, Materials and Chemical Engineering "Giulio Natta", Politecnico di Milano, Milan, Italy; Department of Biomedical Engineering, Thoraxcenter, Erasmus MC, Rotterdam, the Netherlands.
² Department of Mechanical and Production Engineering, Aarhus University, Aarhus, Denmark; Laboratory of Biological Structure Mechanics (LaBS), Department of Chemistry, Materials and Chemical Engineering "Giulio Natta", Politecnico di Milano, Milan, Italy.
³ Laboratory of Biological Structure Mechanics (LaBS), Department of Chemistry, Materials and Chemical Engineering "Giulio Natta", Politecnico di Milano, Milan, Italy.
⁴ Department of Clinical Medicine, Aarhus University, Denmark; Department of MR Research Centre, Aarhus University Hospital, Denmark.
⁵ Department of Clinical Medicine, Aarhus University, Denmark; Department of Cardiology, Aarhus University Hospital, Denmark.
⁶ Cardiovascular Experimental Laboratory (CAVELab), Department of Electrical and Computer Engineering, Aarhus University, Denmark; Department of Cardiothoracic and Vascular Surgery, Aarhus University Hospital, Denmark.
⁷ Department of Mechanical and Production Engineering, Aarhus University, Aarhus, Denmark. Electronic address: mc@mpe.au.dk.

PMID: 40388869
DOI: 10.1016/j.compbiomed.2025.110398

Abstract

Background: Aortic annuloplasty, involving the implantation of an external ring around the aortic root to reduce annular dimensions, is a promising treatment for aortic valve insufficiency. However, its hemodynamic effects remain underexplored due to the absence of computational models validated by experimental and clinical data.

Methods: This study introduces a computational fluid-structure interaction (FSI) model of supra valvular aortic annuloplasty using 4D-flow magnetic resonance imaging (MRI). Native and post-annuloplasty conditions of idealized aortic root phantoms, including the aortic valve, were CAD-modelled and 3D-printed with elastic resin. These phantoms were tested in a mock circulatory flow-loop providing normal pulsatile physiologic conditions using a glycerol-water mixture to simulate blood viscosity. Flow and pressure data collected from sensors were used as boundary conditions for FSI simulations. Experimental velocity fields from 4D-flow MRI were compared to computational results to assess model accuracy.

Results: MRI scans of the annuloplasty model showed an increased peak systolic velocity (up to 145.4 cm/s) and localized flow alterations, corresponding to a higher pressure gradient across the valve. During regurgitation, the annuloplasty model showed broader velocity distributions compared to the native condition. The FSI simulations closely matched 4D-flow MRI data, with strong correlation coefficients (r > 0.93) and minimal Bland-Altman differences, particularly during systolic phases.

Conclusions: This study establishes an integrative methodology combining in-vitro, in-silico, and clinical imaging techniques to evaluate aortic annuloplasty hemodynamics. The in-vitro validated digital twin framework offers a pathway for patient-specific modelling, enabling prediction of surgical outcomes and optimization of aortic valve repair strategies.

Keywords: 4D-flow MRI; Aortic annuloplasty; Digital twin; FSI simulation; Flow-loop; Personalized medicine.

Publication types

Comparative Study

MeSH terms

Aortic Valve Insufficiency* / diagnostic imaging
Aortic Valve Insufficiency* / physiopathology
Aortic Valve Insufficiency* / surgery
Aortic Valve* / diagnostic imaging
Aortic Valve* / physiopathology
Aortic Valve* / surgery
Cardiac Valve Annuloplasty*
Hemodynamics
Humans
Magnetic Resonance Imaging*
Models, Cardiovascular*
Phantoms, Imaging*
Printing, Three-Dimensional*