Numerical simulation of a transcatheter aortic heart valve under application-related loading

Sylvia Pfensig 1 , Sebastian Kaule 2 , Robert Ott 2 , Carolin Wüstenhagen 2 , Michael Stiehm 2 , Jonas Keiler 3 , Andreas Wree 3 , Niels Grabow 4 , Klaus-Peter Schmitz 4  and Stefan Siewert 2
  • 1 Institute for Implant- Technology and Biomaterials e.V., Friedrich-Barnewitz-Str. 4, 18119 Rostock-, Warnemünde, Germany
  • 2 Institute for ImplantTechnology and Biomaterials e.V., 18119 Rostock-, Warnemünde, Germany
  • 3 Department of Anatomy, Rostock University Medical Center, 18057, Rostock, Germany
  • 4 Institute for Biomedical Engineering, Rostock University Medical Center, 18119 Rostock-, Warnemünde, Germany

Abstract

For the treatment of severe symptomatic aortic valve stenosis, minimally invasive heart valve prostheses have more recently become the lifesaving solution for elderly patients with high operational risk and thus, are often implanted in patients with challenging aortic root configuration. A correct prosthesis deployment and stent adaption to the target region is essential to ensure optimal leaflet performance and long-term prosthesis function. The objective of this study was the development of a suitable in silico setup for structural numerical simulation of a transcatheter aortic valve (TAV) in different cases of clinical relevance. A transcatheter valve prosthesis comprising an unpressurized trileaflet heart valve and an adapted stent configuration was designed. An aortic root (AR) model was developed, based on microcomputed tomography of a native healthy specimen. Using the finite-element analysis (FEA), various loading cases including prosthesis biomechanics with valve opening and closing under physiological pressure ratios throughout a cardiac cycle, prosthesis crimping as well as crimping and release into the developed AR model were simulated. Hyperelastic constitutive law for polymeric leaflet material and superelasticity of shape memory alloys for the self-expanding Nitinol stent structure were implemented into the FEA setup. Calculated performance of the valve including the stent structure demonstrated enhanced leaflet opening and closing as a result of stent deformation and redirected loading. Crimping and subsequent release into the AR model as well as the stent adaption to the target region after expansion proved the suitability of the TAV design for percutaneous application. FEA represented a useful tool for numerical simulation of an entire minimally invasive heart valve prosthesis in relevant clinical scenarios.

If the inline PDF is not rendering correctly, you can download the PDF file here.

OPEN ACCESS

Journal + Issues

Current Directions in Biomedical Engineering is an open access journal and closely related to the journal Biomedical Engineering - Biomedizinische Technik. CDBME is a forum for the exchange of knowledge in the fields of biomedical engineering, medical information technology and biotechnology/bioengineering for medicine and addresses engineers, natural scientists, and clinicians working in research, industry, or clinical practice.

Search