3D MRI-Based Modeling for Computer-Aided Right Ventricle Remodeling Surgery

描述(由申请人提供)：先天性心脏手术后晚期发展的右心功能障碍是成人先天性心脏病患者心力衰竭的最常见原因之一。在法洛四联症(ToF)中，最常见的青紫型心脏缺陷，在婴儿期最初的修复涉及到右室流出端的切开和补片，包括肺动脉瓣，这通常会导致严重的右室扩张和功能障碍，原因是慢性肺返流和右室疤痕/补片扩张。目前对晚期RV功能障碍的外科治疗，包括插入肺动脉瓣和减少RV流出补片，减少了RV容量，但不能导致RV功能的可预见的改善。在NHLBI赞助的一项随机前瞻性试验中，正在对一种更激进的手术进行评估，其中包括广泛移除疤痕和流出道补片。然而，目前还没有可用的方法来预测任何一种手术后的结果，或者对于给定的PT来说最佳的手术是什么，也就是说，没有临床上有用的工具来确定患者的特定治疗。在这个项目中，我们建议开发一种计算模型方法来确定各种重建方案的有效性和适宜性，以治疗TOF PTS中失败的RV。我们将使用无创性心脏磁共振成像(CMR)为构建和验证计算模型提供患者特定的RV/LV形态、变形和血流数据。建立基于三维CMR的RV/LV组合模型，包括流体-结构相互作用(RV/LV和RV补片)、两层RV/LV结构、各向异性材料特性、纤维取向和主动收缩，以模拟血流、心脏运动和应力/应变分布，评估不同重塑过程对RV功能的影响，寻求最佳RV体积和补片设计，以改善术后RV功能。正在进行的NHLBI资助的临床试验的临床成像和血流动力学数据将用于建立和验证该模型。我们的最终目标是将这一方法应用于特定患者的计算机辅助心脏手术计划，以达到先天性心脏缺陷所致RV功能障碍患者的最佳手术程序设计和结果。一个由先天性心脏外科、心脏病学和计算数学领域的经验丰富的多学科研究人员组成的小组将开展这一项目。公共卫生相关性：该项目旨在使用从正在接受手术评估的法洛四联症修复术患者获得的MRI图像来建立右室功能的计算模型。最终目标是开发能够预测手术结果并优化术后右室功能的模型。用于这项研究的核磁共振成像是作为这些患者护理的一部分的临床指示研究，目前是根据Tal Geva博士担任首席研究员的批准方案获得的。

DESCRIPTION (provided by applicant): Right ventricular dysfunction developing late after congenital cardiac surgery is one of the most common causes of heart failure in adults with congenital heart disease. In tetra logy of Fallot (ToF), the most common cyanotic heart defect, initial repair in infancy involves an incision and patch in the RV outflow, including the pulmonary valve, which often results in late development of severe RV dilatation and dysfunction due to chronic pulmonary regurgitation and RV scarring/patch dilatation. Current surgical management of late RV dysfunction, consisting of pulmonary valve insertion and reduction of the RV outflow patch, reduces RV volume but does not result in a predictable improvement in RV function. A more radical procedure, which includes extensive removal of scar and outflow patch, is being evaluated in an NHLBI sponsored randomized prospective trial. However, there is no currently available method for predicting outcome after either procedure or what the optimal procedure is for a given pt., i.e. no clinically useful tools for determining patient-specific therapy. In this project, we propose to develop a computational modeling approach to determine the efficacy and suitability of the various reconstructive options to treat failing RV in ToF pts. We will use non-invasive cardiac magnetic resonance imaging (CMR) to provide patient-specific RV/LV morphology, deformation, and flow data for the construction and validation of computational models. 3D CMR-based RV/LV combination models will be constructed, which include fluid-structure interactions (RV/LV and RV patch), two-layer RV/LV structure, anisotropic material properties, fiber orientation, and active contraction to simulate blood flow, heart motion, and stress/strain distribution to evaluate the effect of different remodeling procedures on RV function, and to seek an optimal RV volume and patch design to improve post-operative RV function. Clinical imaging and hemodynamic data from an ongoing NHLBI-funded clinical trial will be used to build and validate the model. Our ultimate goal is to apply this methodology in patient- specific computer-aided cardiac surgery planning to reach optimal surgical procedure design and outcome in patients with RV dysfunction from congenital heart defects. A multidisciplinary group of experienced investigators in congenital cardiac surgery, cardiology and computational mathematics will conduct this project. PUBLIC HEALTH RELEVANCE: This project aims to use MRI images obtained from patients with repair tetralogy of Fallot that are being evaluated for surgery to develop computational models of right ventricular function. The ultimate goal is to develop models that will predict outcomes and optimize right ventricular function after surgery. The MRI's to be used for this study are clinically indicated studies as part of the care of these patients and are currently obtained under an approved protocol where Dr. Tal Geva is the principal investigator.