A numerical study on the influence of the distance between superior vena cave supplying cannulas and inferior vena cave draining cannulas in veno-venous ECMO on right atrial hemodynamics
Objective To clarify the effect of veno-venous extracorporeal membrane oxygenation (VV-ECMO) superior and inferior Cannula distance on hemodynamic environment in right atrium.Methods A three-dimensional model of the right atrium was established based on the MRI image data of a respiratory failure patient ' s heart.The superior vena cava supplying and inferior vena cava draining models were established based on the Medtronic,23Fr cannulas.Then,three fluid-structure interaction models were established for the ratio of the distance between the superior vena cava supplying and inferior vena cava draining and the distance between the superior and inferior vena cava,which were 38％,88％,and 126％,respectively.Finally,transient computational fluid dynamics methods were used to study the hemodynamic state in the right atrium.The parameters such as blood flow velocity cloud maps,recirculation fraction(RF),wall shear stress,volume of low flow velocity areas in the right atrium,and relative residence time (RRT) were used to evaluate hemodynamic changes in the right atrium at different distances of superior and inferior cannula.Results As the distance between the superior vena cava supplying and inferior vena cava draining increased,the total volume of the low flow velocity area in the right atrium first decreased and then increased (468 mm3 vs.327.47 mm3 vs.357.7 mm3),the maximum relative residence time first decreased and then increased (103.54 Pa-1 vs.70.60 Pa-1 vs.95.15 Pa-1) and the recirculation fraction rate continues to decrease (23.295％ vs.20.918％ vs.10.88％) .Conclusions The improvement of volume in the low flow rate area and relative residence time is not linear with the increase of cannula spacing.When the cannula spacing increases to a certain distance,continuing to increase the cannula spacing will actually worsen the volume in the low flow rate area and relative residence time.The recirculation fraction continuously improves with the increase of cannula spacing.
万方数据
维普
