Transcatheter aortic valve implantation (TAVI)

Introduction

The increase of life expectancy and, consequently, of population average age has favored the genesis and progression of degenerative cardiovascular diseases. In particular, aortic valve stenosis due to calcification is the most frequent aortic valve disorder [R1; R2]. In this case, aortic valve replacement represents the most common surgical remedy. However, open heart surgery with cardiopulmonary bypass is not always recommended: in presence of coexisting conditions such as advanced age, congestive heart failure, coronary artery disease, lung disease and renal insufficiency, the surgical risk becomes very high and, in some cases, unsustainable. For this reason, over the last decade, minimally-invasive procedures have been developed to avoid high risks associated with conventional open-chest valve replacement techniques. In particular, percutaneous valves are adopted to restore valve functionality: a heart valve, sewn inside a stent, is crimped and properly placed in the patient’s heart by means of a catheter. Such a recent and innovative procedure represents an optimal field for investigations through virtual computer-based simulations.

Goal

The goal of our study is to virtually reproduce, by means of numerical tools, the surgical operation in order to predict possible postoperative results in patient-specific cases.

Methods

The modeling procedure is quite complex and requires different steps. First of all, geometrical models of both percutaneous devices from microCT records and patient’s aortic root from CTA images are created. Then, finite element analyses of balloon inflation, device anchoring and postoperative valve performance are performed taking into account the presence of calcific plaques. The effects of using different prosthesis types/sizes, and of choosing different placement sites may be virtually reproduced and investigated through FEA [P1, P2].

Results

References

  • [R1] AHA committee. Heart disease and stroke statistics 2010 update: A report from the american heart association. Circulation, 121:e46-e215,2010.
  • [R2] Iung B., G. Baron, E.G. Butchart, F. Delahaye, C. Gohlke-Barwolf, O.W. Levang, P. Tornos, J.-L. Vanoverschelde, F. Vermeer, E. Boersma, P. Ravaud, and A. Vahanian. A prospective survey of patients with valvular heart disease in europe: The euro heart survey on valvular heart disease. European Heart Journal, 24:1231-1243, 2003.

Group publications

  • [P1] Auricchio F., M. Conti, S. Morganti, and A. Reali. Simulation of transcatheter aortic valve implantation: a patient-specific finite element approach. Computer Methods in Biomechanics and Biomedical Engineering. http://dx.doi.org/10.1080/10255842.2012.746676, 2013.
  • [P2] Auricchio F., M. Conti, S. Morganti, and A. Reali. Impact of aortic root anatomy on transcatheter aortic valve implantation: a patient-specific finite element study. In preparation.