Department of Biomedical Engineering, Johns Hopkins University, 3400 N Charles Street, Baltimore, MD 21218.
Department of Mechanical Engineering, Johns Hopkins University, 3400 N Charles Street, Baltimore, MD 21218.
J Biomech Eng. 2024 Dec 1;146(12). doi: 10.1115/1.4066178.
Pulmonary valves do not display a fibrous annulus as do other valves in the heart; thus, pulmonary valves can be implanted at multiple orientations and locations within the right ventricular outflow tract (RVOT). This gives surgeons more freedom when implanting the valve but it also results in uncertainties regarding placement, particularly with respect to valve orientation. We investigate the pulmonary artery hemodynamics and valve leaflet dynamics of pulmonary valve replacements (PVRs) with various orientations via fluid-structure interaction (FSI) models. A canonical model of the branching pulmonary artery is coupled with a dynamic model of a pulmonary valve, and from this we quantify the effect of valve implant orientation on the postvalvular hemodynamics and leaflet dynamics. Metrics such as turbulent kinetic energy (TKE), branch pulmonary artery flow distributions, projected valve opening area (PVOA), and pressure differentials across the valve leaflets are analyzed. Our results indicate that off-axis orientation results in higher pressure forces and flow and energy asymmetry, which potentially have implications for long-term durability of implanted bioprosthetic valves.
肺瓣膜不像心脏中的其他瓣膜那样具有纤维环；因此，肺瓣膜可以在右心室流出道（RVOT）内的多个方向和位置植入。这为外科医生在植入瓣膜时提供了更大的自由度，但也导致了对植入位置的不确定性，特别是对瓣膜方向的不确定性。我们通过流固耦合（FSI）模型研究了各种方向的肺动脉瓣置换（PVR）的肺动脉血流动力学和瓣叶动力学。分支肺动脉的典型模型与肺动脉瓣的动态模型相结合，由此我们量化了瓣膜植入方向对瓣后血流动力学和瓣叶动力学的影响。分析了诸如湍流动能（TKE）、分支肺动脉血流分布、投影瓣开口面积（PVOA）和瓣叶之间的压力差等指标。我们的结果表明，偏心方向会导致更高的压力和流量以及能量不对称，这可能对植入的生物瓣的长期耐久性产生影响。
