Hemodynamic analysis of modified Blalock-Taussig shunt: Effects of anastomosis angle of the conduit on pulmonary flow

To treat cyanotic congenital heart defect, modified Blalock-Taussig (mB-T) shunt is an effective procedure used in clinic. The pulmonary artery is bridged by a conduit with the systemic circulation to increase the flow of blood. Here, we report on three-dimensional (3D) hemodynamic analysis of the effects of conduit anastomosis angle on pulmonary flow. A 3D model based on post-operative medical images of the mB-T shunt was constructed and computer-aided design (CAD) was applied to create a new model with vertical anastomosis angle of the conduit at pulmonary artery. Local hemodynamics like total pressure, wall shear stress (WSS) and blood flow distribution ratio (FDR) were calculated. The scheme of vertical anastomosis angle of the conduit on the pulmonary artery can increase the blood flow distribution to two lungs and blood flows more smoothly in the conduit. These are well congruent with our clinical experience. This indicates the numerical methods can be applied to investigate hemodynamics of the mB-T shunt for the prediction of pulmonary flow and optimized the conduit implantation by virtual design for patient-specific surgery in future.