Design of implantable blood flow manipulator for improving fluid dynamics at the total cavo-pulmonary connection(TCPC), a computational fluid dynamic study

Background :At present the commonly performed Fontan variant is described as total cavopulmonary connection (TCPC) with SVC-IVC offset. From fluid mechanics point of view, there are two main problems encountered late postoperatively in these TCPC patients :
1. Asymmetric streaming of IVC blood to the offset side of the lungs depriving contra-lateral lung of hepatic factor necessary for lung growth eventually causing arteriovenous malformations in that lung.
2. Energy loss due to collision of vena caval blood streams when SVC and IVC are anastomosed to right pulmonary artery without offset. Moreover, this energy loss is aggravated due to phase and amplitude differences between SVC an IVC flows
In order to reduce the flow abnormalities at the total cavopulmonary junction, implantable passive flow manipulator is designed and its efficacy is assessed by computation fluid dynamic tools. Further these tools help in optimizing the geometrical parameters of implant.

Method: The computation flow dynamic study include the creation of idealized geometry, mesh generation, setting up of boundary conditions and numerical analysis for different flow and pressure within patho-physiological range. The simulation is carried out by varying the geometry of implant.

Conclusion: The study shows the mechanism of its effectiveness by simulation experiments under varying flow and pressure conditions. Maximum benefits in terms of pwer saving and even flow distribution of inferior vena caval stream by shape optimization of implant.