Caballero Andrés, Mao Wenbin, McKay Raymond, Hahn Rebecca T, Sun Wei
Tissue Mechanics Laboratory, The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, United States.
Division of Cardiology, The Hartford Hospital, Hartford, CT, United States.
Front Physiol. 2020 May 7;11:432. doi: 10.3389/fphys.2020.00432. eCollection 2020.
Percutaneous edge-to-edge mitral valve (MV) repair using MitraClip has been recently established as a treatment option for patients with heart failure and functional mitral regurgitation (MR), which significantly expands the number of patients that can be treated with this device. This study aimed to quantify the morphologic, hemodynamic and structural changes, and evaluate the biomechanical interaction between the MitraClip and the left heart (LH) complex of a heart failure patient with functional MR using a fluid-structure interaction (FSI) modeling framework. MitraClip implantation using lateral, central and double clip positions, as well as combined annuloplasty procedures were simulated in a patient-specific LH model that integrates detailed anatomic structures, incorporates age- and gender-matched non-linear elastic material properties, and accounts for mitral chordae tethering. Our results showed that antero-posterior distance, mitral annulus spherecity index, anatomic regurgitant orifice area, and anatomic opening orifice area decreased by up to 28, 39, 52, and 71%, respectively, when compared to the pre-clip model. MitraClip implantation immediately decreased the MR severity and improved the hemodynamic profile, but imposed a non-physiologic configuration and loading on the mitral apparatus, with anterior and posterior leaflet stress significantly increasing up to 210 and 145% during diastole, respectively. For this patient case, while implanting a combined central clip and ring resulted in the highest reduction in the regurgitant volume (46%), this configuration also led to mitral stenosis. Patient-specific computer simulations as used here can be a powerful tool to examine the complex device-host biomechanical interaction, and may be useful to guide device positioning for potential favorable clinical outcomes.
使用MitraClip进行经皮缘对缘二尖瓣（MV）修复最近已成为心力衰竭和功能性二尖瓣反流（MR）患者的一种治疗选择，这显著扩大了可使用该装置治疗的患者数量。本研究旨在使用流固耦合（FSI）建模框架，量化一名患有功能性MR的心力衰竭患者的形态学、血流动力学和结构变化，并评估MitraClip与左心（LH）复合体之间的生物力学相互作用。在一个特定患者的LH模型中模拟了使用外侧、中央和双夹位置的MitraClip植入，以及联合瓣环成形术，该模型整合了详细的解剖结构，纳入了年龄和性别匹配的非线性弹性材料特性，并考虑了二尖瓣腱索的束缚作用。我们的结果表明，与夹闭前模型相比，前后距离、二尖瓣环球形指数、解剖反流口面积和解剖开口口面积分别减少了高达28%、39%、52%和71%。MitraClip植入立即降低了MR严重程度并改善了血流动力学状况，但给二尖瓣装置带来了非生理性的构型和负荷，舒张期前后叶应力分别显著增加高达210%和145%。对于该患者病例，虽然植入中央夹和瓣环联合装置导致反流体积减少最多（46%），但这种构型也导致了二尖瓣狭窄。此处使用的特定患者计算机模拟可以成为研究复杂的装置-宿主生物力学相互作用的有力工具，并且可能有助于指导装置定位以获得潜在的良好临床结果。
