双向双侧格林手术的数值研究

Numerical study on bilateral bidirectional Glenn shunt

目的利用数值模拟方法预测左上腔静脉与肺动脉的连接位置改变对双向双侧格林(BBDG)手术的影响。方法首先,根据拥有左上腔静脉的单心室心脏缺陷综合征病人的医学图像重建出三维几何模型。其次,基于力反馈器创建其他数值模拟所需的模型,并利用有限体积法进行流体力学的数值模拟。最后,分析与评估获得的血流动力学参数。结果血液在左、右上腔静脉与肺主动脉中进行再循环。左上腔静脉到右上腔静脉之间的距离由右上腔静脉直径的2倍逐渐变化到右上腔静脉直径的3.5倍,发现当距离为3倍直径时,能量损失最少,而距离为2倍时,能量损失最大。血液分流比(左肺动脉流量/右肺动脉流量)的计算结果范围为0.65～1.11。结论在BBDG手术的治疗中,左、右上腔静脉之间距离太近会导致不适宜的分流比以及消耗更多的能量。本研究结果对于评价伴随有左上腔静脉的单心室心脏缺陷综合征的治疗手术是非常有意义的。

Objective To predict the influence of connecting position between left superior vena cava（LSVC） and pulmonary artery on bilateral bidirectional Glenn（BBDG） shunt by numerical simulation.Methods Firstly,a 3D anatomical geometrical model was reconstructed by the medical images of a hypoplastic left heart syndrome（HLHS） patient with LSVC.Secondly,based on haptic deformations,several computational models were virtually generated,and computational fluid dynamics（CFD） numerical simulations were conducted using finite volume method.Finally,hemodynamic parameters were analyzed and evaluated.Results Flow recirculation was observed in the pulmonary artery between the LSVC and right superior vena cava（RSVC）.The diameter of RSVC was defined as D.Varying the distance between LSVC and RSVC from 2D to 3.5D resulted in the least energy dissipation at 3D and the most at 2D.The blood flow rate ratios of left pulmonary artery to right pulmonary artery（LPA/RPA） ranged from 0.65-1.11.Conclusions Too close distance between LSVC and RSVC would bring out unfavorable hemodynamic distributions and consume more energy in the treatment of BBDG shunt.This study is of significance for surgeons to evaluate the optimal Fontan options in the treatment of HLHS accompanied by LSVC.