计算流体力学模拟在功能性单心室患儿虚拟Fontan手术中的应用

目的 对双侧、双向Glenn术后患儿进行虚拟Fontan手术,并对不同设计方案的血管吻合区域内血流进行计算流体力学(computational fluid dynamics,CFD)模拟.方法 利用Mimics 12.0(R) 进行三维解剖重建,通过虚拟手术改变双侧上腔静脉与肺动脉的吻合位置,并将下腔静脉连接到肺动脉的不同位置.建立数值模型,对4种虚拟手术方案在不同左、右肺动脉流量分配比(30:70、40:60、50:50、60:40、70:30)情况下的血流进行CFD模拟.结果 当左、右上腔静脉与肺动脉吻合口之间距离较大且下腔静脉与肺动脉吻合口位于中间时,在各种左、右肺动脉流量分配比情况下能量消耗均较其他3种设计方案低,且在左、右肺动脉流量分配比为50:50时能量消耗达到最低值23.60 mW.结论 对患有左侧上腔静脉残存的患儿施行Fontan手术时,将左、右上腔静脉分别吻合于同侧肺动脉并将下腔静脉与肺动脉吻合口置于左、右上腔静脉与肺动脉吻合口中间的设计方案能量消耗最低.

Application of computational fluid dynamic simulations on the virtual Fontan operations for the patients with the functional single ventricle

Objective To perform the virtual Fontan operations on patients who had undergone the bilateral bidirectional Glenn procedure, and to simulate the blood flow in different types of opera-tive strategies by the method of computational fluid dynamics (CFD). Methods Three-dimensional re-construction was performed with Mimics 12. 0(R) according to the results of magnetic resonance imaging (MRI). Virtual operations were performed by changing the virtual anastomotic sites of bilateral supe-rior vena cava (SVC) and pulmonary arteries (PAs), and by connecting the inferior vena cava (IVC) to different sites of PAs. Numerical simulations were established to analyze the CFD of blood flows in patients undergoing 4 different types of virtual operative strategies at different predetermined flow split distribution ratios of left pulmonary artery (LPA) to right pulmonary artery (RPA) (at 30: 70,40 : 60, 50:50,60:40 and 70:30, respectively). Results When the distance between the anastomotic sites of the bilateral SVCs to the PAs was relatively long and the anastomotic site of IVC and PAs was in the middle of the SVC-PA anastomotic sites, the control volume power loss (CVPL) was lower than any other three operative strategies at all predetermined LPA/RPA flow split distribution ratios. The CV-PL achieved a minimal value of 23.60 mW at the ratio of 50/50. Conclusions For Fontan operations, it may be the optimal operative strategy to anastomose bilateral SVCs to the homolateral PA separately and to connect the IVC in the middle of the SVC-PA anastomotic sites.