HEMODYNAMIC INFLUENCE OF CONDUIT POSITION ON SYSTEMIC-TO-PULMONARY SHUNT: COMPUTATIONAL ANALYSIS OF PATIENT-SPECIFIC SURGICAL DESIGN
Jinlong Liu1, Yi Qian2, Mitsuo Umezu3, Jinfen Liu1
1Shanghai Children’s Medical Center, China;
2Macquarie University, Australia; 3Centre for Advanced Biomedical Sciences, TWIns, Waseda University, Japan
The systemic-to-pulmonary artery shunt is one kind of palliative procedure. It is the most preferred surgery used in the first staged therapy of cyanotic congenital heart defect (CHD). The blood flow in systemic circulation was introduced to pulmonary artery by a Gore-Tex conduit to promote oxygen saturation in this procedure. However, the position of the conduit implantation is one of contentious issues for surgeons in the design of surgery. Here, we report on our threedimensional hemodynamic analysis of patient-specific researches of the conduit position by using the techniques of computational fluid dynamics (CFD). A series of continuous CT images were acquired for the reconstruction of the 3D vascular geometric models. Computer-aided design (CAD) was employed to create a conduit with 4 mm in diameter and virtually imitate the implantation of the conduit in different positions based on vascular anatomical structures. Three common applied surgical forms of systemicto-pulmonary artery shunt in clinic were created to simulate the procedure of the modified BlalockTaussig (mB-T) shunt, Center aorto-pulmonary shunt and Melbourne shunt, respectively. Pressure drops, wall shear stress (WSS), streamlines and blood flow distribution ratio were quantitatively compared to disclose the influence of conduit position. The results indicate the mB-T shunt is more effective to control the balance of blood flow distributed to systemic and pulmonary circulation. The relative higher pressure of pulmonary was generated in Center aorto-pulmonary shunt and Melbourne shunt. To control the high WSS created in the shunt may reduce the risk of thrombosis formation. The methods of CFD and CAD are a useful tool for patient-specific surgical design in the treatment of CHD.