动脉导管对改良Blalock-Taussig分流术的血流动力学影响

The hemodynamic effects of ductus arteriosus on modified Blalock-Taussig shunt

目的通过计算流体力学分析关闭或保留动脉导管对改良Blalock-Taussig分流术后血流动力学的影响,为术前规划和术后血流动力学预测提供参考。方法基于患者个体化肺动脉闭锁合并动脉导管未闭的三维血管模型,通过计算机辅助设计对模型进行虚拟改良Blalock-Taussig分流术,保留或关闭动脉导管。利用计算血流动力学方法分析比较术前及虚拟术后的血流参数差异。结果保留动脉导管竞争性减少通过分流管的血流量,但肺血流量增加。通过分流管的血流与通过动脉导管的血流相互冲击,在肺动脉形成复杂湍流,具有低壁面切应力与高振荡剪切指数,可导致较高的流动能量损失。结论行改良Blalock-Taussig术时保留动脉导管将导致肺血流过多、体循环灌注不足、增加心脏负荷及心力衰竭风险,并不能降低潜在的血栓风险。

Objective To investigate hemodynamic characteristics of the modified Blalock-Taussig shunt(MBTS)with the preservation or ligation of ductus arteriosus(DA)based on computational fluid dynamics(CFD),thus to help preoperative surgery design and postoperative prediction.Methods A patient with pulmonary atresia and patent ductus arteriosus was included.Patient-specific three-dimensional model was reconstructed and virtual surgeries of shunt insertion and ductus ligation or preservation were performed via computer-aided design(CAD).CFD was utilized to analyze hemodynamic parameters preoperatively and postoperatively based on patient-specific anatomy and physiologic data.Results The preservation of DA competitively reduced the shunt flow but increased total pulmonary perfusion.The shunt flow and ductal flow collided with each other,causing large and complicated turbulence in pulmonary artery where lower wall shear stress and higher oscillatory shear index were distributed,as well as higher energy loss.Conclusion The preservation of DA is riskier in hemodynamics which may lead to pulmonary over-perfusion,inadequate systemic perfusion and heavier cardiac burden,thus increasing the risk of heart failure and it seems to bring no benefit in terms of reducing risks of thrombosis.