Shear Stress Alterations in the Celiac Trunk of Patients with Continuous-Flow Left Ventricular Assist Device by In-Silico and In-Vitro Flow Analysis
Wednesday 23rd November 2016
Scardulla, S.; Pasta, S.; D’Acquisto, L.; Sciacca, S.; Agnese, V.; Vergara, C.; Quarteroni, A.; Clemenza, F.; Bellavia, D.; Pilato, M.
Background: The use of left ventricular assist device (LVAD) to treat advanced cardiac heart failure is constantly increasing, although this device leads to high risk for gastrointestinal. Methods: Using in-silico flow analysis, we quantified hemodynamic alterations due to continuous-flow LVAD (HeartWare Inc, Framingham, MA, USA) in the celiac trunk and major branches of the abdominal aorta and then explored the relationship between wall shear stress (WSS) and celiac trunk orientation. To assess outflow from aortic branch, a 3D printed patient-specific model of the celiac trunk reconstructed from a LVAD-supported patient was used to estimate echocardiographic outflow velocities under continuous-flow conditions and then to calibrate computational simulations. Moreover, flow pattern and resulting WSS were computed on 5 patients with LVAD implantation. Results: Peak WSSs were estimated on the three branches of celiac trunk and the LVAD cannula. Mean values of WSS demonstrated that the left gastric artery experiences the greatest WSS of 9.08±5.45 Pa with an average flow velocity of 0.57±0.25 m/s when compared to that of other vessel districts. The common hepatic artery had the less critical WSS of 4.58±1.77 Pa. A positive correlation was found between the celiac trunk angulation and the WSS stress just distal the ostium of celiac trunk (R=0.9), and this may increase to vulnerability of this vessel to bleeding. Conclusions: Although further studies are warranted to confirm these findings in a larger patient cohort, computational flow simulations may enhance the information of clinical image data and may have an application in clinical investigations of hemodynamic changes in LVAD-supported patients.