基于体-肺动脉分流术血流动力学特点的先天性心脏病虚拟手术研究

The procedure of the systemic-to-pulmonary shunt is a common and effective method for the children with the severe cyanotic congenital heart diseases. It is a palliative procedure to increase pulmonary blood flow and alleviate cyanosis in surgical planning for the pulmonary atresia, usually serving as the first step of staged procedures. By surgically connected the systemic and pulmonary artery through an artificial conduit, blood from the systemic circulation can flow into the lungs. The surgical technique improved over the years. However, it is still a challenge to select a proper conduit with a suitable length, diameter and anastomosis angle or position to control appropriate distribution of blood flow. Post-operative thrombosis, unbalance lung perfusion and occlusion, distortion of the conduit can be founded to cause severe complications. Numerous researches illustrate the abnormal hemodynamics is suspected to be the main reason around the connection area of the systemic-to-pulmonary shunt...In the previous studies, with the support of National Nature Science Foundation of China, we established a medical image-based computational hemodynamic system for Fontan procedure. However, the system cannot work properly under complex conditions with considering multiple physiological elements in systemic and pulmonary circulations. And also, it cannot be used to investigate the formation of thrombosis caused by hemorheology and its non-Newtonian fluid characteristics. Therefore, we propose to establish a new computational hemodynamic system based on the previous experience and the fluid experiments of Micro-PIV measurements for the study of hemorheology. The new medical image-based computational hemodynamic system and the technique of computer-aided design will be utilized not only to optimize the systemic-to-pulmonary shunt and its application by virtual surgery, but also to disclose the internal relation between the formation mechanism of thrombosis and its local abnormal hemodynamics. The study will improve the understanding of the local hemodynamic characteristics for future treatment in surgical design of the systemic-to-pulmonary shunt.

体-肺动脉分流术是一种应用于治疗新生儿复杂紫绀型先心病的姑息疗法，被广泛用于复杂先心病合并肺动脉严重发育不良的临床治疗中。术中常采用生物管道或人工管道，但目前对管道直径、长度、吻合位置的选取缺乏客观、精准的判断依据，故易致术后管道扭曲、梗阻、牵拉和肺血流灌注不均衡等问题的发生而引起严重并发症，影响患儿后期手术治疗，研究表明这与分流管内异常血流动力学特性密切相关。.受先前国家自然科学基金支持，本团队成功建立适用于研究Fontan手术血流动力学模拟系统，但其无法同时兼顾多生理因素作用下主动脉和肺动脉血流的特点，也无法研究与血栓形成机制相关的血液流变学非牛顿流体特性。本研究拟通过微尺度PIV流体实验改进计算模拟方法，以开展虚拟手术研究，探索个体化体-肺动脉分流术的最优血流动力学，揭示异常血流动力学因素与管道梗阻、血栓形成机制之间的内在联系，为帮助医生术中选择最佳体-肺动脉分流术分流方案提供参考。

体-肺动脉分流术是一类用于治疗新生儿复杂紫绀型先心病的姑息手术，目前被广泛用于复杂先心病合并肺动脉严重发育不良的临床治疗中。术中常采用生物管道或人工管道建立体肺循环分流通路，增加肺血流灌注。但是，目前缺乏对管道直径、长度、吻合位置选取的客观、精准的判断依据，导致术后管道扭曲、梗阻、牵拉和肺血流灌注不均衡等问题的发生，进而引起严重并发症，影响患儿后期手术治疗，研究表明这与分流管内异常血流动力学特性密切相关。. 本研究基于已有血流动力学计算模拟系统，兼顾多生理因素作用下主动脉和肺动脉血流特点，结合血液流变学非牛顿流体特性，通过微尺度PIV流体实验验证改进计算模拟方法，建立起用于定量研究血流脉动状态下不同术式体-肺动脉分流术分流管道内血流动力学计算模拟分析体系，并深入探讨了不同管道直径、形态、吻合口位置和吻合口角度对体-肺动脉分流管道内血流动力学的影响。通过本研究的开展，初步明确了影响不同体-肺动脉分流术分流管内梗阻形成及两侧肺灌注不均衡的血流动力学因素，揭示了异常血流动力学因素与管道梗阻、血栓形成机制之间的内在联系。在此基础上，本研究还探索利用计算机辅助设计及3D打印技术开展虚拟手术设计，寻找不同术式的体-肺动脉分流术个体化最优血流动力学手术方案设计，并结合临床随访，为未来合理设计个体化治疗手术操作流程，帮助医师选择最佳体-肺动脉分流术分流方案，建立切实可行的血液动力学定量评估标准提供参考。