Biomaterial optimization in a percutaneous aortic valve stent using finite element analysis.
BACKGROUND
Vascular support structures are important devices for treating valve stenosis. Large population of patients are treated for valvular disease and the principal mode of treatment is the use of percutaneous valvuloplasty. Stent devices are proving to be an improved technology in minimal invasive cardiac surgery. This technology now accounts for 20% of treatments in Europe. This new technology provides highly effective results at minimal cost and short duration of hospitalization.


METHODS
This paper discusses the design and finite element analysis (FEA) of a percutaneous aortic valve stent. The stent design was modeled and subjected to FEA. The improved model design was carried out to meet the functional and surgical requirements. Analysis was done with different materials with loads ranging from 50 to 73 kgf/mm(2). These forces were selected because these values are far greater than the normal human blood pressure which ranges from 10 to 16 kPa. It was also to understand the mechanical behavior of different stent materials under such high pressures.


RESULTS
A stent model was generated and its physical, mechanical, and behavioral properties were studied. Finite element analysis and simulation of the model help the designer to optimize the geometry suitable for performance during and after implantation. The design objective for the stent is to have long-term durability, low thrombogenicity, and resistance to migration and paravalvular leak.


CONCLUSIONS
The analysis performed in this paper may aid in understanding the stent's tolerable pressure ranges in comparison with the physiological pressures exerted by the heart and cardiac blood flow during abnormal cardiovascular conditions. It may also help in finding the material that will best suit the stent.
Kumar
Gideon V Praveen
GV
School of Biotechnology, Chemical and Biomedical Engineering, VIT University, Vellore 632002, India. gidi99_5611@yahoo.co.in
Mathew
Lazar
L
D001021:Aortic Valve; D001024:Aortic Valve Stenosis / Q000503:physiopathology / Q000628:therapy*; D001672:Biocompatible Materials; D002404:Catheterization / Q000295:instrumentation*; D002858:Chromium Alloys; D003198:Computer Simulation; D055119:Elastic Modulus; D019544:Equipment Failure Analysis; D020342:Finite Element Analysis; D006350:Heart Valve Prosthesis; D006439:Hemodynamics; D006801:Humans; D008422:Materials Testing; D009532:Nickel; D011312:Pressure; D011474:Prosthesis Design; D011475:Prosthesis Failure; D013193:Stainless Steel; D015607:Stents; D013314:Stress, Mechanical; D014025:Titanium
D001672:Biocompatible Materials; D002858:Chromium Alloys; D013193:Stainless Steel; D009532:Nickel; D014025:Titanium