TY - JOUR
T1 - Numerical model of the aortic root and valve
T2 - Optimization of graft size and sinotubular junction to annulus ratio
AU - Marom, Gil
AU - Halevi, Rotem
AU - Haj-Ali, Rami
AU - Rosenfeld, Moshe
AU - Schäfers, Hans Joachim
AU - Raanani, Ehud
N1 - Funding Information:
This work was partially supported by a grant from the Nicholas and Elizabeth Slezak Super Center for Cardiac Research and Biomedical Engineering at Tel Aviv University .
PY - 2013/11
Y1 - 2013/11
N2 - Objective: The aim of this study was to determine the influence of aortic annulus (AA) diameter and the ratio of the sinotubular junction (STJ) diameter to the AA diameter on aortic valve hemodynamics and tissue mechanics and to suggest optimal values. Methods: Sixteen cases of aortic roots with AA diameters between 22 and 28 mm and an STJ/AA diameter ratio between 0.8 and 1.4 were numerically modeled. Average coaptation height and mechanical stresses were calculated from 3-dimensional finite element analysis of the aortic valve and root. Five additional fluid structure interaction (FSI) models with an AA diameter of 24 mm and an STJ/AA ratio between 0.6 and 1.4 were also constructed. The material properties of the tissues were from porcine valves and boundary conditions were physiologic and normal blood pressures. Results: In most cases, average coaptation height decreased with an increase in the STJ/AA ratio. Those cases with AA diameters between 24 and 26 mm and an STJ/AA ratio between 0.8 and 1.0 had a relatively large average coaptation height (>3 mm) and similar stress distribution during diastole. The flow shear stress values on the cusps at peak systole increased at the same time as the STJ/AA ratio decreased, similar to the opening area. Conclusions: Relatively large coaptation, low stress in the tissues during diastole, and low flow shear stress during systole is the best combination for cases of AA diameter between 24 and 26 mm with identical STJ diameter. Valve-sparing procedures that prevent AA expansion are preferable.
AB - Objective: The aim of this study was to determine the influence of aortic annulus (AA) diameter and the ratio of the sinotubular junction (STJ) diameter to the AA diameter on aortic valve hemodynamics and tissue mechanics and to suggest optimal values. Methods: Sixteen cases of aortic roots with AA diameters between 22 and 28 mm and an STJ/AA diameter ratio between 0.8 and 1.4 were numerically modeled. Average coaptation height and mechanical stresses were calculated from 3-dimensional finite element analysis of the aortic valve and root. Five additional fluid structure interaction (FSI) models with an AA diameter of 24 mm and an STJ/AA ratio between 0.6 and 1.4 were also constructed. The material properties of the tissues were from porcine valves and boundary conditions were physiologic and normal blood pressures. Results: In most cases, average coaptation height decreased with an increase in the STJ/AA ratio. Those cases with AA diameters between 24 and 26 mm and an STJ/AA ratio between 0.8 and 1.0 had a relatively large average coaptation height (>3 mm) and similar stress distribution during diastole. The flow shear stress values on the cusps at peak systole increased at the same time as the STJ/AA ratio decreased, similar to the opening area. Conclusions: Relatively large coaptation, low stress in the tissues during diastole, and low flow shear stress during systole is the best combination for cases of AA diameter between 24 and 26 mm with identical STJ diameter. Valve-sparing procedures that prevent AA expansion are preferable.
UR - http://www.scopus.com/inward/record.url?scp=84885916361&partnerID=8YFLogxK
U2 - 10.1016/j.jtcvs.2013.01.030
DO - 10.1016/j.jtcvs.2013.01.030
M3 - ???researchoutput.researchoutputtypes.contributiontojournal.article???
AN - SCOPUS:84885916361
SN - 0022-5223
VL - 146
SP - 1227
EP - 1231
JO - Journal of Thoracic and Cardiovascular Surgery
JF - Journal of Thoracic and Cardiovascular Surgery
IS - 5
ER -