title: A computational fluid dynamics comparison between different outflow graft anastomosis locations of Left Ventricular Assist Device (LVAD) in a patient-specific aortic model.
abstract: Left ventricular assist devices (LVADs) are mechanical supports used in case of heart failure. Little is known as the height of the anastomosis in aorta might influence the hemodynamic. The aim of the study was to evaluate the fluid dynamic behavior due to the outflow graft placement of a continuous flow LVAD in ascending aorta and to identify the insertion site with the best hemodynamic profile. Computational fluid dynamic studies were carried out to analyze 4 different anastomosis locations in a patient-specific aorta 3D model coupled with a lumped parameters model: 1 cm (case 1), 2 cm (case 2), 3 cm (case 3) and 4 cm (case 4) above the ST junction. In cases 1 and 2, epiaortic vessels presented a steady flow, while in cases 3 and 4 the flow was whirling. Moreover, maximum velocity occurred before: brachiocephalic trunk (case 1), brachiocephalic and left carotid arteries (case 2), left carotid and left subclavian artery (case 3) and left subclavian vessel and upper wall of aortic arch (case 4). Maximum time averaged wall shear stress (TAWSS) was located in: the ascending aorta (cases 1 and 2), the inferior curvature of the arch (case 3); at the origin of epiaortic vessels (case 4). Furthermore, a flow recirculation (cases 1 and 2), a blood stagnation and chaotic flow (cases 3 and 4) occurred above the aortic valve. The results suggested that the placement of the outflow graft at 2 cm above the ST junction gave the most favorable hemodynamic profile.
authors.affiliation: Bioengineering Unit, Magna Graecia University, Catanzaro, Italy.
authors.forename: Maria Vittoria
authors.initials: MV
authors.lastname: Caruso
authors.forename: Vera
authors.initials: V
authors.lastname: Gramigna
authors.forename: Michele
authors.initials: M
authors.lastname: Rossi
authors.forename: Giuseppe Filiberto
authors.initials: GF
authors.lastname: Serraino
authors.forename: Attilio
authors.initials: A
authors.lastname: Renzulli
authors.forename: Gionata
authors.initials: G
authors.lastname: Fragomeni
mesh_terms: D000714:Anastomosis, Surgical; D001011:Aorta / Q000503:physiopathology* / Q000601:surgery*; D003198:Computer Simulation; D006353:Heart-Assist Devices; D006801:Humans; D057446:Hydrodynamics; D008297:Male; D008875:Middle Aged; D008955:Models, Cardiovascular; D013314:Stress, Mechanical; D013599:Systole; D013997:Time Factors; D058067:Wavelet Analysis
keywords: aorta; computational fluid dynamic; hemodynamic; left ventricular assist device; lumped parameters model