title: Numerical simulation of left ventricular assist device implantations: comparing the ascending and the descending aorta cannulations.
abstract: In this work we present numerical simulations of continuous flow left ventricle assist device implantation with the aim of comparing difference in flow rates and pressure patterns depending on the location of the anastomosis and the rotational speed of the device. Despite the fact that the descending aorta anastomosis approach is less invasive, since it does not require a sternotomy and a cardiopulmonary bypass, its benefits are still controversial. Moreover, the device rotational speed should be correctly chosen to avoid anomalous flow rates and pressure distribution in specific location of the cardiovascular tree. With the aim of assessing the differences between these two approaches and device rotational speed in terms of flow rate and pressure waveforms, we set up numerical simulations of network of one-dimensional models where we account for the presence of an outflow cannula anastomosed to different locations of the aorta. Then, we use the resulting network to compare the results of the two different cannulations for several stages of heart failure and different rotational speed of the device. The inflow boundary data for the heart and the cannulas are obtained from a lumped parameters model of the entire circulatory system with an assist device, which is validated with clinical data. The results show that ascending and descending aorta cannulations lead to similar waveforms and mean flow rate in all the considered cases. Moreover, regardless of the anastomosis region, the rotational speed of the device has an important impact on wave profiles; this effect is more pronounced at high RPM.
authors.affiliation: CMCS, Chair of Modelling and Scientific Computing, MATHICSE, Mathematics Institute of Computational Science and Engineering, EPFL, École Polytechnique Fédérale de Lausanne, Station 8, CH-1015 Lausanne, Switzerland. jean.bonnemain@gmail.com
authors.forename: Jean
authors.initials: J
authors.lastname: Bonnemain
authors.forename: A Cristiano I
authors.initials: AC
authors.lastname: Malossi
authors.forename: Matteo
authors.initials: M
authors.lastname: Lesinigo
authors.forename: Simone
authors.initials: S
authors.lastname: Deparis
authors.forename: Alfio
authors.initials: A
authors.lastname: Quarteroni
authors.forename: Ludwig K
authors.initials: LK
authors.lastname: von Segesser
mesh_terms: D001013:Aorta, Thoracic / Q000502:physiology / Q000503:physiopathology / Q000601:surgery*; D001775:Blood Circulation; D001794:Blood Pressure; D002404:Catheterization / Q000295:instrumentation*; D003198:Computer Simulation; D006333:Heart Failure / Q000503:physiopathology / Q000601:surgery; D006352:Heart Ventricles / Q000503:physiopathology / Q000601:surgery*; D006353:Heart-Assist Devices; D006801:Humans
keywords: Blood flow models; Geometrical multiscale modeling; Hemodynamics; Left ventricular assist device; Wave propagation