Hoda Hatoum1, Jennifer Dollery2, Scott M Lilly3, Juan A Crestanello2, Lakshmi Prasad Dasi4. 1. Department of Biomedical Engineering, The Ohio State University, Columbus, Ohio. 2. Division of Cardiac Surgery, The Ohio State University, Columbus, Ohio. 3. Division of Cardiovascular Medicine, The Ohio State University, Columbus, Ohio. 4. Department of Biomedical Engineering, The Ohio State University, Columbus, Ohio; Division of Cardiac Surgery, The Ohio State University, Columbus, Ohio. Electronic address: lakshmi.dasi@osumc.edu.
Abstract
BACKGROUND: This study evaluated the effect of transcatheter aortic valve implantation depth and rotation on pressure gradient (PG), leakage fractions (LF), leaflet shear stress, and sinus washout in an effort to understand factors that may dictate optimal positioning for valve-in-valve (ViV) procedures. Sinus flow stasis is often associated with prosthetic leaflet thrombosis. Although recent ViV in vitro studies highlighted potential benefits of transcatheter aortic valve supraannular implantation to minimize PGs, the relationship between transcatheter aortic valve depth and other determinates of valve function remains unknown. Among these, LFs, shear stress, and poor sinus washout have been associated with poorer valve outcomes. METHODS: ViV hemodynamic performance was evaluated in vitro vs axial positions -9.8, -6.2, 0, and +6 mm and angular orientations 0, 30, 60, and 90 degrees in a degenerated surgical aortic valve. PGs, LFs, and sinus shear stress and washout were compared. Leaflet high-speed imaging and particle-image velocimetry were performed to elucidate hemodynamic mechanisms. RESULTS: (1) The PG varies as a function of axial position, with supraannular deployments yielding a maximum benefit of 7.85 mm Hg less than PGs for subannular deployments irrespective of commissural alignment (p < 0.01); (2) in contrast, LF decreased in relationship to subannular deployment; and (3) at peak systole, sinus flow shear stress increased with deployment depth as did sinus washout with and without coronary flow. CONCLUSIONS: First, supraannular axial deployment is associated with lower PGs irrespective of commissural alignment. Second, subannular deployment is associated with more favorable sinus hemodynamics and less LF. Further in vivo studies are needed to substantiate these observations and facilitate optimal prosthesis positioning during ViV procedures.
BACKGROUND: This study evaluated the effect of transcatheter aortic valve implantation depth and rotation on pressure gradient (PG), leakage fractions (LF), leaflet shear stress, and sinus washout in an effort to understand factors that may dictate optimal positioning for valve-in-valve (ViV) procedures. Sinus flow stasis is often associated with prosthetic leaflet thrombosis. Although recent ViV in vitro studies highlighted potential benefits of transcatheter aortic valve supraannular implantation to minimize PGs, the relationship between transcatheter aortic valve depth and other determinates of valve function remains unknown. Among these, LFs, shear stress, and poor sinus washout have been associated with poorer valve outcomes. METHODS: ViV hemodynamic performance was evaluated in vitro vs axial positions -9.8, -6.2, 0, and +6 mm and angular orientations 0, 30, 60, and 90 degrees in a degenerated surgical aortic valve. PGs, LFs, and sinus shear stress and washout were compared. Leaflet high-speed imaging and particle-image velocimetry were performed to elucidate hemodynamic mechanisms. RESULTS: (1) The PG varies as a function of axial position, with supraannular deployments yielding a maximum benefit of 7.85 mm Hg less than PGs for subannular deployments irrespective of commissural alignment (p < 0.01); (2) in contrast, LF decreased in relationship to subannular deployment; and (3) at peak systole, sinus flow shear stress increased with deployment depth as did sinus washout with and without coronary flow. CONCLUSIONS: First, supraannular axial deployment is associated with lower PGs irrespective of commissural alignment. Second, subannular deployment is associated with more favorable sinus hemodynamics and less LF. Further in vivo studies are needed to substantiate these observations and facilitate optimal prosthesis positioning during ViV procedures.
Authors: Tina Leetmaa; Nicolaj C Hansson; Jonathon Leipsic; Kaare Jensen; Steen H Poulsen; Henning R Andersen; Jesper M Jensen; John Webb; Philipp Blanke; Mariann Tang; Bjarne L Nørgaard Journal: Circ Cardiovasc Interv Date: 2015-04 Impact factor: 6.546
Authors: Tarun Chakravarty; Lars Søndergaard; John Friedman; Ole De Backer; Daniel Berman; Klaus F Kofoed; Hasan Jilaihawi; Takahiro Shiota; Yigal Abramowitz; Troels H Jørgensen; Tanya Rami; Sharjeel Israr; Gregory Fontana; Martina de Knegt; Andreas Fuchs; Patrick Lyden; Alfredo Trento; Deepak L Bhatt; Martin B Leon; Raj R Makkar Journal: Lancet Date: 2017-03-19 Impact factor: 79.321
Authors: Hoda Hatoum; Jennifer Dollery; Scott M Lilly; Juan A Crestanello; Lakshmi Prasad Dasi Journal: J Biomech Date: 2018-05-04 Impact factor: 2.712