In vitro 4D Flow MRI evaluation of aortic valve replacements reveals disturbed flow distal to biological but not to mechanical valves.
4D Flow MRI
aorta and great vessels
cardiovascular research
valve repair/replacement
Journal
Journal of cardiac surgery
ISSN: 1540-8191
Titre abrégé: J Card Surg
Pays: United States
ID NLM: 8908809
Informations de publication
Date de publication:
Dec 2019
Dec 2019
Historique:
pubmed:
23
10
2019
medline:
6
6
2020
entrez:
23
10
2019
Statut:
ppublish
Résumé
Aortic hemodynamics influence the integrity of the vessel wall and cardiac afterload. The aim of this study was to compare hemodynamics distal to biological (BV) and mechanical aortic valve (MV) replacements by in vitro 4D Flow MRI excluding confounding factors of in-vivo testing potentially influencing hemodynamics. Two BV (Perimount MagnaEase [Carpentier-Edwards], Trifecta [Abbott]) and two MV (On-X [CryoLife], prototype trileaflet valve) were scanned in a flexible aortic phantom at 3T using a recommended 4D Flow MR sequence. A triphasic aortic flow profile with blood-mimicking fluid was established. Using GTFlow (Gyrotools), area and velocity of the ejection jet were measured. Presence and extent of sinus vortices and secondary flow patterns were graded on a 0 to 3 scale. A narrow, accelerated central ejection jet (Area = 27 ± 7% of vessel area, Velocity = 166 ± 13 cm/s; measured at sinotubular junction) was observed in BV as compared to MV (Area = 53 ± 13%, Velocity = 109 ± 21 cm/s). As opposed to MV, the jet distal to BV impacted the outer curvature of the ascending aorta and resulted in large secondary flow patterns (BV: n = 4, grades 3, 3, 2, 1; MV: n = 1, grade 1). Sinus vortices only formed distal to MV. Although physiologically configured, they were larger than normal (grade 3). In contrast to mechanical valves, biological valve replacements induced accelerated and increased flow patterns deviating from physiological ones. While it remains speculative whether this increases the risk of aneurysm formation through wall shear stress changes, findings are contrasted by almost no secondary flow patterns and typical, near-physiological sinus vortex formation distal to mechanical valves.
Sections du résumé
BACKGROUND AND AIM OF THE STUDY
OBJECTIVE
Aortic hemodynamics influence the integrity of the vessel wall and cardiac afterload. The aim of this study was to compare hemodynamics distal to biological (BV) and mechanical aortic valve (MV) replacements by in vitro 4D Flow MRI excluding confounding factors of in-vivo testing potentially influencing hemodynamics.
METHODS
METHODS
Two BV (Perimount MagnaEase [Carpentier-Edwards], Trifecta [Abbott]) and two MV (On-X [CryoLife], prototype trileaflet valve) were scanned in a flexible aortic phantom at 3T using a recommended 4D Flow MR sequence. A triphasic aortic flow profile with blood-mimicking fluid was established. Using GTFlow (Gyrotools), area and velocity of the ejection jet were measured. Presence and extent of sinus vortices and secondary flow patterns were graded on a 0 to 3 scale.
RESULTS
RESULTS
A narrow, accelerated central ejection jet (Area = 27 ± 7% of vessel area, Velocity = 166 ± 13 cm/s; measured at sinotubular junction) was observed in BV as compared to MV (Area = 53 ± 13%, Velocity = 109 ± 21 cm/s). As opposed to MV, the jet distal to BV impacted the outer curvature of the ascending aorta and resulted in large secondary flow patterns (BV: n = 4, grades 3, 3, 2, 1; MV: n = 1, grade 1). Sinus vortices only formed distal to MV. Although physiologically configured, they were larger than normal (grade 3).
CONCLUSIONS
CONCLUSIONS
In contrast to mechanical valves, biological valve replacements induced accelerated and increased flow patterns deviating from physiological ones. While it remains speculative whether this increases the risk of aneurysm formation through wall shear stress changes, findings are contrasted by almost no secondary flow patterns and typical, near-physiological sinus vortex formation distal to mechanical valves.
Types de publication
Journal Article
Langues
eng
Sous-ensembles de citation
IM
Pagination
1452-1457Informations de copyright
© 2019 Wiley Periodicals, Inc.
Références
Davies PF. Flow-mediated endothelial mechanotransduction. Physiol Rev. 1995;75(3):519-560. https://doi.org/10.1152/physrev.1995.75.3.519
Bellhouse BJ, Bellhouse FH, Reid KG. Fluid mechanics of the aortic root with application to coronary flow. Nature. 1968;219(5158):1059-1061.
Oechtering TH, Hons CF, Sieren M, et al. Time-resolved 3-dimensional magnetic resonance phase contrast imaging (4D Flow MRI) analysis of hemodynamics in valve-sparing aortic root repair with an anatomically shaped sinus prosthesis. J Thorac Cardiovasc Surg. 2016;152(2):418-427. https://doi.org/10.1016/j.jtcvs.2016.04.029
Grande-Allen KJ, Cochran RP, Reinhall PG, Kunzelman KS. Re-creation of sinuses is important for sparing the aortic valve: a finite element study. J Thorac Cardiovasc Surg. 2000;119(4):753-763. https://doi.org/10.1016/S0022-5223(00)70011-0
Pisani G, Scaffa R, Ieropoli O, et al. Role of the sinuses of Valsalva on the opening of the aortic valve. J Thorac Cardiovasc Surg. 2013;145(4):999-1003. https://doi.org/10.1016/j.jtcvs.2012.03.060
Keller EJ, Malaisrie SC, Kruse J, et al. Reduction of aberrant aortic haemodynamics following aortic root replacement with a mechanical valved conduit. Interact Cardiovasc Thorac Surg. 2016;23(3):416-423. https://doi.org/10.1093/icvts/ivw173
Bollache E, Fedak PWM, van Ooij P, et al. Perioperative evaluation of regional aortic wall shear stress patterns in patients undergoing aortic valve and/or proximal thoracic aortic replacement. J Thorac Cardiovasc Surg. 2018;155(6):2277-2286. https://doi.org/10.1016/j.jtcvs.2017.11.007
von Knobelsdorff-Brenkenhoff F, Trauzeddel RF, Barker AJ, Gruettner H, Markl M, Schulz-Menger J. Blood flow characteristics in the ascending aorta after aortic valve replacement--a pilot study using 4D-flow MRI. Int J Cardiol. 2014;170(3):426-433. https://doi.org/10.1016/j.ijcard.2013.11.034
Collins JD, Semaan E, Barker A, et al. Comparison of hemodynamics after aortic root replacement using valve-sparing or bioprosthetic valved conduit. Ann Thorac Surg. 2015;100(5):1556-1562. https://doi.org/10.1016/j.athoracsur.2015.04.109
van Kesteren F, Wollersheim LW, Baan J Jr., et al. Four-dimensional flow MRI of stented versus stentless aortic valve bioprostheses. Eur Radiol. 2018;28(1):257-264. https://doi.org/10.1007/s00330-017-4953-2
Trauzeddel RF, Lobe U, Barker AJ, et al. Blood flow characteristics in the ascending aorta after TAVI compared to surgical aortic valve replacement. Int J Cardiovasc Imaging. 2016;32(3):461-467. https://doi.org/10.1007/s10554-015-0792-x
Farag ES, Schade EL, van Ooij P, et al. Bileaflet mechanical aortic valves do not alter ascending aortic wall shear stress. Int J Cardiovasc Imaging. 2019;35(4):703-710. https://doi.org/10.1007/s10554-018-1508-9
Hellmeier F, Nordmeyer S, Yevtushenko P, et al. Hemodynamic evaluation of a biological and mechanical aortic valve prosthesis using patient-specific MRI-based CFD. Artif Organs. 2018;42(1):49-57. https://doi.org/10.1111/aor.12955
Frydrychowicz A, Berger A, Munoz Del Rio A, et al. Interdependencies of aortic arch secondary flow patterns, geometry, and age analysed by 4-dimensional phase contrast magnetic resonance imaging at 3 Tesla. Eur Radiol. 2012;22(5):1122-1130. https://doi.org/10.1007/s00330-011-2353-6
Kvitting JP, Dyverfeldt P, Sigfridsson A, et al. In vitro assessment of flow patterns and turbulence intensity in prosthetic heart valves using generalized phase-contrast MRI. J Magn Reson Imaging. 2010;31(5):1075-1080. https://doi.org/10.1002/jmri.22163
Giese D, Weiss K, Baeßler B, et al. In vitro evaluation of flow patterns and turbulent kinetic energy in trans-catheter aortic valve prostheses. MAGMA. 2018;31(1):165-172. https://doi.org/10.1007/s10334-017-0651-y
Sievers HH, Schubert K, Jamali A, Scharfschwerdt M. The influence of different inflow configurations on computational fluid dynamics in a novel three-leaflet mechanical heart valve prosthesis. Interact Cardiovasc Thorac Surg. 2018;27(4):475-480. https://doi.org/10.1093/icvts/ivy086
Dyverfeldt P, Bissell M, Barker AJ, et al. 4D flow cardiovascular magnetic resonance consensus statement. J Cardiovasc Magn Reson. 2015;17(1):72. https://doi.org/10.1186/s12968-015-0174-5
Kilner PJ, Yang GZ, Mohiaddin RH, Firmin DN, Longmore DB. Helical and retrograde secondary flow patterns in the aortic arch studied by three-directional magnetic resonance velocity mapping. Circulation. 1993;88(5 Pt 1):2235-2247.
Oechtering TH, Sieren MM, Hunold P, et al. Time-resolved 3-dimensional magnetic resonance phase contrast imaging (4D Flow MRI) reveals altered blood flow patterns in the ascending aorta of patients with valve-sparing aortic root replacement. J Thorac Cardiovasc Surg. 2019. https://doi.org/10.1016/j.jtcvs.2019.02.127
Binter C, Knobloch V, Manka R, Sigfridsson A, Kozerke S. Assessment of energy loss across aortic valves using accelerated CMR multi-point flow measurements. J Cardiovasc Magn Reson. 2012;14(Suppl 1) W9, 1-2, https://doi.org/10.1186/1532-429X-14-S1-W9
Bissell MM, Loudon M, Hess AT, et al. Differential flow improvements after valve replacements in bicuspid aortic valve disease: a cardiovascular magnetic resonance assessment. J Cardiovasc Magn Reson. 2018;20(1):10. https://doi.org/10.1186/s12968-018-0431-5
Kozerke S, Hasenkam JM, Pedersen EM, Boesiger P. Visualization of flow patterns distal to aortic valve prostheses in humans using a fast approach for cine 3D velocity mapping. J Magn Reson Imaging. 2001;13(5):690-698.
Babin-Ebell J, Sievers HH, Misfeld M, Runge M, Vogt PR, Scharfschwerdt M. In-vitro hemodynamics of stented bioprosthetic heart valves in the tilted implantation position. J Heart Valve Dis. 2008;17(5):566-570.
Pennekamp W, Geyhan N, Soeren P, Volkmar N. Determination of flow profiles of different mechanical aortic valve prostheses using phase-contrast MRI. J Cardiovasc Surg. 2011;52(2):277-284.
Fujita B, Ensminger S, Bauer T, et al. Trends in practice and outcomes from 2011 to 2015 for surgical aortic valve replacement: an update from the German Aortic Valve Registry on 42 776 patients. Eur J Cardiothorac Surg. 2018;53(3):552-559. https://doi.org/10.1093/ejcts/ezx408