Author + information
- Marco Zuin, MD,
- Gianluca Rigatelli, MD, PhD,
- Giuseppe Faggian, MD and
- Loris Roncon, MD∗ ()
- ↵∗Department of Cardiology, Santa Maria della Misericordia Hospital, Viale Tre Martiri 140, 45100 Rovigo, Italy
Nowadays, mathematical and numerical models are becoming increasingly important in cardiovascular medicine. In mathematics, the finite element method (FEM) is a numerical technique used to analyze complex structures. This method subdivided a whole problem domain into simpler parts, called finite elements (FEs). Although mathematics might seem of little utility in clinical practice, several clinical reports have shown that altered flow conditions, such as flow reversal, shear stress, and flow separation, are fundamental factors in the development of arterial diseases. In this setting, the possibility to understand and predict hemodynamic alterations and long-term adaptation of the cardiovascular system, before and after surgical or interventional procedures, could be a very useful tool for surgeons and cardiologists, also for modifying their therapeutic strategies. In cardiovascular modeling, the geometric proprieties of heart and vessels are generally derived from magnetic resonance imaging, computed tomography, or angiography and then converted into the FE geometry using special commercial software. On the other hand, the material physics properties are derived from existing biomechanical studies of the tissue involved. Conventionally, computer simulation of solid and fluid structure interactions is based on the Arbitrary Lagrangian-Eulerian method. Different cardiovascular diseases have been studied via this process. Cupps et al. (1) examined the regional left ventricle wall stress in aortic regurgitation (AR) and normal systolic function, showing that it was significantly higher compared with patients with normal aortic valves. In a similar way, AR has been studied, analyzing both leaflet stress and strain (2). Computational fluid dynamic analysis (CFD) was also applied to assess the residual stress produced by ventricular volume reduction surgery, demonstrating the small postoperative effect on left ventricular function. Instead, Toeg et al. (3) focused their analysis, using the FEM, on the “ideal” biomaterial for aortic valve repair (AVr), considering that in past years, AVr has become an attractive alternative to aortic valve replacement. Similarly, Qiao et al. (4) assessed the reason of neo-aortic valve insufficiency after Ross procedure. The problem of AR due to a congenitally undersized leaflet was studied by some cardiac surgeons, who have shown that aortic root reduction can improve valve closure and eliminate regurgitation, but the result is strongly connected to both the shape and size of the resected area. Ascending thoracic aortic aneurysms were analyzed through CFD analysis which investigated aneurysm wall stress, identifying the site most prone to rupture. The mitral valve was studied by the FEM, in both normal conditions (analyzing its deformation under physiological loading conditions) and in pathological conditions. Recently, some researchers evaluated the possibility of assessing optimal mitral valve repair in a small cohort of patients using the FEM, opening the way to patient-specific optimization of surgical treatment through cardiovascular modeling. Important findings have also emerged regarding cavopulmonary shunts: the classic Norwood central shunt and the modified Blalock-Taussig procedure have been described and compared. Moreover, application of mathematical computational methods have been used as the basis for coronary angiography/computed tomography–based prediction of fractional flow reserve relative to the coronary artery lesion and for predicting coronary bifurcation adaptation to different stenting techniques (5). Multiple applications of the FEM in cardiac surgery and interventional cardiology are in the pipeline. In the near future, the FEM will be a modeling tool that will allow realization of a patient-specific approach.
Please note: The authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- American College of Cardiology Foundation