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Lopez-Santana G, De Rosis A, Grant S, Venkateswaran R, Keshmiri A. Enhancing the implantation of mechanical circulatory support devices using computational simulations. Front Bioeng Biotechnol 2024; 12:1279268. [PMID: 38737533 PMCID: PMC11084291 DOI: 10.3389/fbioe.2024.1279268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 04/08/2024] [Indexed: 05/14/2024] Open
Abstract
Introduction: Patients with end-stage heart failure (HF) may need mechanical circulatory support such as a left ventricular assist device (LVAD). However, there are a range of complications associated with LVAD including aortic regurgitation (AR) and thrombus formation. This study assesses whether the risk of developing aortic conditions can be minimised by optimising LVAD implantation technique. Methods: In this work, we evaluate the aortic flow patterns produced under different geometrical parameters for the anastomosis of the outflow graft (OG) to the aorta using computational fluid dynamics (CFD). A three-dimensional aortic model is created and the HeartMate III OG positioning is simulated by modifying (i) the distance from the anatomic ventriculo-arterial junction (AVJ) to the OG, (ii) the cardinal position around the aorta, and (iii) the angle between the aorta and the OG. The continuous LVAD flow and the remnant native cardiac cycle are used as inlet boundaries and the three-element Windkessel model is applied at the pressure outlets. Results: The analysis quantifies the impact of OG positioning on different haemodynamic parameters, including velocity, wall shear stress (WSS), pressure, vorticity and turbulent kinetic energy (TKE). We find that WSS on the aortic root (AoR) is around two times lower when the OG is attached to the coronal side of the aorta using an angle of 45° ± 10° at a distance of 55 mm. Discussion: The results show that the OG placement may significantly influence the haemodynamic patterns, demonstrating the potential application of CFD for optimising OG positioning to minimise the risk of cardiovascular complications after LVAD implantation.
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Affiliation(s)
- Gabriela Lopez-Santana
- School of Engineering, The University of Manchester, Manchester, United Kingdom
- Department of Cardiothoracic Transplantation and Mechanical Circulatory Support, Wythenshawe Hospital, Manchester, United Kingdom
| | - Alessandro De Rosis
- School of Engineering, The University of Manchester, Manchester, United Kingdom
| | - Stuart Grant
- Manchester University NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, United Kingdom
- Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom
| | - Rajamiyer Venkateswaran
- Department of Cardiothoracic Transplantation and Mechanical Circulatory Support, Wythenshawe Hospital, Manchester, United Kingdom
- Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom
| | - Amir Keshmiri
- School of Engineering, The University of Manchester, Manchester, United Kingdom
- Manchester University NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, United Kingdom
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Schultz MG, Davies JE, Hardikar A, Pitt S, Moraldo M, Dhutia N, Hughes AD, Sharman JE. Aortic Reservoir Pressure Corresponds to Cyclic Changes in Aortic Volume. Arterioscler Thromb Vasc Biol 2014; 34:1597-603. [DOI: 10.1161/atvbaha.114.303573] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Objective—
Aortic reservoir pressure indices independently predict cardiovascular events and mortality. Despite this, there has never been a study in humans to determine whether the theoretical principles of the mathematically derived aortic reservoir pressure (RP
derived
) and excess pressure (XP
derived
) model have a real physiological basis. This study aimed to directly measure the aortic reservoir (AR
direct
; by cyclic change in aortic volume) and determine its relationship with RP
derived
, XP
derived
, and aortic blood pressure (BP).
Approach and Results—
Ascending aortic BP and Doppler flow velocity were recorded via intra-arterial wire in 10 men (aged 62±12 years) during coronary artery bypass surgery. Simultaneous ascending aortic transesophageal echocardiography was used to measure AR
direct
. Published mathematical formulae were used to determine RP
derived
and XP
derived
. AR
direct
was strongly and linearly related to RP
derived
during systole (
r
=0.988;
P
<0.001) and diastole (
r
=0.985;
P
<0.001). Peak cross-correlation (
r
=0.98) occurred at a phase lag of 0.004 s into the cardiac cycle, suggesting close temporal agreement between waveforms. The relationship between aortic BP and AR
direct
was qualitatively similar to the cyclic relationship between aortic BP and RP
derived
, with peak cross-correlations occurring at identical phase lags (AR
direct
versus aortic BP,
r
=0.96 at 0.06 s; RP
derived
versus aortic BP,
r
=0.98 at 0.06 s).
Conclusions—
RP
derived
is highly correlated with changes in proximal aortic volume, consistent with its physiological interpretation as corresponding to the instantaneous volume of blood stored in the aorta. Thus, aortic reservoir pressure should be considered in the interpretation of the central BP waveform.
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Affiliation(s)
- Martin G. Schultz
- From the Menzies Research Institute Tasmania, University of Tasmania, Hobart, Tasmania, Australia (M.G.S., A.H., J.E.S.); International Centre for Circulatory Health, Imperial College London, London, United Kingdom (J.E.D., M.M, N.D.); Royal Hobart Hospital, Hobart, Tasmania, Australia (S.P.); and Institute of Cardiovascular Science, University College London, London, United Kingdom (A.D.H.)
| | - Justin E. Davies
- From the Menzies Research Institute Tasmania, University of Tasmania, Hobart, Tasmania, Australia (M.G.S., A.H., J.E.S.); International Centre for Circulatory Health, Imperial College London, London, United Kingdom (J.E.D., M.M, N.D.); Royal Hobart Hospital, Hobart, Tasmania, Australia (S.P.); and Institute of Cardiovascular Science, University College London, London, United Kingdom (A.D.H.)
| | - Ashutosh Hardikar
- From the Menzies Research Institute Tasmania, University of Tasmania, Hobart, Tasmania, Australia (M.G.S., A.H., J.E.S.); International Centre for Circulatory Health, Imperial College London, London, United Kingdom (J.E.D., M.M, N.D.); Royal Hobart Hospital, Hobart, Tasmania, Australia (S.P.); and Institute of Cardiovascular Science, University College London, London, United Kingdom (A.D.H.)
| | - Simon Pitt
- From the Menzies Research Institute Tasmania, University of Tasmania, Hobart, Tasmania, Australia (M.G.S., A.H., J.E.S.); International Centre for Circulatory Health, Imperial College London, London, United Kingdom (J.E.D., M.M, N.D.); Royal Hobart Hospital, Hobart, Tasmania, Australia (S.P.); and Institute of Cardiovascular Science, University College London, London, United Kingdom (A.D.H.)
| | - Michela Moraldo
- From the Menzies Research Institute Tasmania, University of Tasmania, Hobart, Tasmania, Australia (M.G.S., A.H., J.E.S.); International Centre for Circulatory Health, Imperial College London, London, United Kingdom (J.E.D., M.M, N.D.); Royal Hobart Hospital, Hobart, Tasmania, Australia (S.P.); and Institute of Cardiovascular Science, University College London, London, United Kingdom (A.D.H.)
| | - Niti Dhutia
- From the Menzies Research Institute Tasmania, University of Tasmania, Hobart, Tasmania, Australia (M.G.S., A.H., J.E.S.); International Centre for Circulatory Health, Imperial College London, London, United Kingdom (J.E.D., M.M, N.D.); Royal Hobart Hospital, Hobart, Tasmania, Australia (S.P.); and Institute of Cardiovascular Science, University College London, London, United Kingdom (A.D.H.)
| | - Alun D. Hughes
- From the Menzies Research Institute Tasmania, University of Tasmania, Hobart, Tasmania, Australia (M.G.S., A.H., J.E.S.); International Centre for Circulatory Health, Imperial College London, London, United Kingdom (J.E.D., M.M, N.D.); Royal Hobart Hospital, Hobart, Tasmania, Australia (S.P.); and Institute of Cardiovascular Science, University College London, London, United Kingdom (A.D.H.)
| | - James E. Sharman
- From the Menzies Research Institute Tasmania, University of Tasmania, Hobart, Tasmania, Australia (M.G.S., A.H., J.E.S.); International Centre for Circulatory Health, Imperial College London, London, United Kingdom (J.E.D., M.M, N.D.); Royal Hobart Hospital, Hobart, Tasmania, Australia (S.P.); and Institute of Cardiovascular Science, University College London, London, United Kingdom (A.D.H.)
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