Charité - Universitätsmedizin Berlin, Berlin, Germany.
German Heart Institute Berlin - DHZB, Berlin, Germany.
Int J Comput Assist Radiol Surg. 2018 Nov;13(11):1795-1805. doi: 10.1007/s11548-018-1821-8. Epub 2018 Jul 14.
Severe mitral valve regurgitation can either be treated by a replacement or a repair of the valve. The latter is recommended due to lower perioperative mortality and better long-term survival. On the other hand, recurrence rates after mitral valve repair are high compared to those after replacements and the repair intervention can cause induced mitral valve stenosis. So far, there are no methods to predict the hemodynamic outcome of a chosen treatment or to compare different treatment options in advance. To overcome this, diastolic mitral valve hemodynamics are simulated using computational fluid dynamics after different virtual treatments of the valve.
The left ventricular geometry of one patient was reconstructed using trans-esophageal echocardiography and computed tomography data. Pre-op hemodynamics are simulated using a referenced wall model to avoid expansive modeling of wall motion. Subsequently, the flow structures are compared to in vivo measurements. After manipulating the patient-specific geometry in order to mimic a restrictive mitral annuloplasty as well as a MitraClip intervention, hemodynamics results are calculated.
Good agreements exist between calculated pre-op hemodynamics and in vivo measurements. The virtual annuloplasty did not result in any remarkable change of hemodynamics. Neither the pressure drop nor the velocity field showed strong differences. In contrast, the virtual MitraClip intervention led to a complete change in blood flow structures as well as an elevated pressure drop across the valve.
The presented approach allows fast simulation of the diastolic hemodynamic situation before and after treatment of a mitral valve insufficiency. However, this approach is limited to the early diastolic phase of the cardiac cycle and needs to be validated using a larger sample size.
严重的二尖瓣反流可以通过瓣膜置换或修复来治疗。由于围手术期死亡率较低和长期生存较好，建议采用后者。另一方面，与置换相比，二尖瓣修复后的复发率较高，而且修复干预可能导致继发性二尖瓣狭窄。到目前为止，还没有方法可以预测所选择治疗的血流动力学结果，也无法提前比较不同的治疗方案。为了克服这个问题，使用计算流体动力学对瓣膜进行不同的虚拟治疗后，模拟舒张期二尖瓣血流动力学。
使用经食管超声心动图和计算机断层扫描数据重建一位患者的左心室几何形状。使用参考壁模型模拟术前血流动力学，以避免对壁运动进行扩展建模。随后，将流结构与体内测量值进行比较。在对患者特定的几何形状进行操作以模拟限制性二尖瓣环成形术和 MitraClip 干预后，计算血流动力学结果。
计算的术前血流动力学与体内测量值之间存在良好的一致性。虚拟环成形术并没有导致血流动力学发生显著变化。压力降或速度场均没有明显差异。相比之下，虚拟 MitraClip 干预导致血流结构完全改变，瓣膜跨压升高。
所提出的方法可以在二尖瓣关闭不全治疗前后快速模拟舒张期血流动力学情况。然而，这种方法仅限于心动周期的早期舒张期，需要使用更大的样本量进行验证。
