In-vivo assessment of the morphology and hemodynamic functions of the BioValsalva™ composite valve-conduit graft using cardiac magnetic resonance imaging and computational modelling technologyReport as inadecuate




In-vivo assessment of the morphology and hemodynamic functions of the BioValsalva™ composite valve-conduit graft using cardiac magnetic resonance imaging and computational modelling technology - Download this document for free, or read online. Document in PDF available to download.

Journal of Cardiothoracic Surgery

, 9:193

First Online: 09 December 2014Received: 14 July 2014Accepted: 27 November 2014

Abstract

BackgroundThe evaluation of any new cardiac valvular prosthesis should go beyond the classical morbidity and mortality rates and involve hemodynamic assessment. As a proof of concept, the objective of this study was to characterise for the first time the hemodynamics and the blood flow profiles at the aortic root in patients implanted with BioValsalva™ composite valve-conduit using comprehensive MRI and computer technologies.

MethodsFour male patients implanted with BioValsalva™ and 2 age-matched normal controls NC underwent cardiac magnetic resonance imaging MRI. Phase-contrast imaging with velocity-mapping in 3 orthogonal directions was performed at the level of the aortic root and descending thoracic aorta. Computational fluid dynamic CFD simulations were performed for all the subjects with patient-specific flow information derived from phase-contrast MR data.

ResultsThe maximum and mean flow rates throughout the cardiac cycle at the aortic root level were very comparable between NC and BioValsalva™ patients 541 ± 199 vs. 567 ± 75 ml-s and 95 ± 46 vs. 96 ± 10 ml-s, respectively. The maximum velocity cm-s was higher in patients 314 ± 49 vs. 223 ± 20; P = 0.06 due to relatively smaller effective orifice area EOA, 2.99 ± 0.47 vs. 4.40 ± 0.24 cm P = 0.06, however, the BioValsalva™ EOA was comparable to other reported prosthesis. The cross-sectional area and maximum diameter at the root were comparable between the two groups. BioValsalva™ conduit was stiffer than the native aortic wall, compliance mm • mmHg • 10 values were 12.6 ± 4.2 vs 25.3 ± 0.4.; P = 0.06. The maximum time-averaged wall shear stress Pa, at the ascending aorta was equivalent between the two groups, 17.17 ± 2.7 NC vs. 17.33 ± 4.7 BioValsalva™ . Flow streamlines at the root and ascending aorta were also similar between the two groups apart from a degree of helical flow that occurs at the outer curvature at the angle developed near the suture line.

ConclusionsBioValsalva™ composite valve-conduit prosthesis is potentially comparable to native aortic root in structural design and in many hemodynamic parameters, although it is stiffer. Surgeons should pay more attention to the surgical technique to maximise the reestablishment of normal smooth aortic curvature geometry to prevent unfavourable flow characteristics.

KeywordsComposite valve-conduit Aortic valve Aortic root Aortic prosthesis BioValsalva Computational fluid dynamic Electronic supplementary materialThe online version of this article doi:10.1186-s13019-014-0193-6 contains supplementary material, which is available to authorized users.

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Author: Emaddin Kidher - Zhuo Cheng - Omar A Jarral - Declan P O’Regan - Xiao Yun Xu - Thanos Athanasiou

Source: https://link.springer.com/



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