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You are here: Contents > 2015 > Volume 24 Number 1 January 2015 > AORTIC VALVE DISEASE > High Transcatheter Valve Replacement May Reduce Washout in the Aortic Sinuses: An In-Vitro Study

High Transcatheter Valve Replacement May Reduce Washout in the Aortic Sinuses: An In-Vitro Study

Gautam Kumar1,2, Vrishank Raghav3, Stamatios Lerakis1,3, Ajit P. Yoganathan3

1Emory University, Department of Medicine, Division of Cardiology, Atlanta, GA, 2Atlanta VA Medical Center, Department of Medicine, Division of Cardiology, Decatur, GA, 3Wallace H. Coulter Department of Biomedical Engineering at Georgia Institute of Technology and Emory University, Atlanta GA, USA

Background and aim of the study: Transcatheter aortic valve replacements (TAVRs) are performed using fluoroscopic guidance, which makes precise positioning challenging. The aim of the present study was to investigate the effect of TAV positioning on flow characteristics in the ascending aorta and sinuses.

Methods: A commonly used TAV design with a supra-annular support section was investigated using particle image velocimetry (PIV) under physiological flow and pressure conditions. A bioprosthetic valve served as a control and mimicked the native aortic valve. The valve assembly was mounted in a custom-designed chamber with an axisymmetric sinus, the design of which was based on anatomic dimensions. The TAV was deployed in the supra-annular (high) and subannular (low) implantation positions and studied at two cardiac outputs (5.0 and 2.5 l/min).

Results: The TAV showed good systolic flow characteristics

with wide forward flow jets in the ascending aorta (V = 1.5 m/s at 5.0 l/min; V = 1.0 m/s at 2.5 l/min). In the high implantation, the physical spacing between the leaflet free edge and sinotubular junction was reduced (<10 mm), causing a weaker sinus vortex and a lower washout. A larger region of low velocity (<0.1 m/s) in the sinus was observed at high implantation at all time points, particularly at a cardiac output of 2.5 l/min. In the low implantation, good sinus washout was observed.

Conclusion: For optimal sinus washout, subannular TAV deployment is recommended, particularly for patients with smaller sinuses. An impaired cardiac output may also require subannular deployment for adequate sinus washout. The study results confirmed the need for precise TAV deployment tailored to patient-specific annular and sinus dimensions, as sub-optimal positioning may inhibit coronary perfusion and cause potential regions of stasis near the aortic annulus.

The Journal of Heart Valve Disease 2014;23:683-687

High Transcatheter Valve Replacement May Reduce Washout in the Aortic Sinuses: An In-Vitro Study

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