Prisco Anthony R, Aliseda Alberto, Beckman Jennifer A, Mokadam Nahush A, Mahr Claudius, Garcia Guilherme J M
From the *Department of Biomedical Engineering, Medical College of Wisconsin, Milwaukee, Wisconsin; †Department of Medicine, University of Minnesota, Minneapolis, Minnesota; ‡Department of Mechanical Engineering, University of Washington, Seattle, Washington; §Department of Medicine, Division of Cardiology, University of Washington, Seattle, Washington; ¶Department of Surgery, Division of Cardiothoracic Surgery, University of Washington, Seattle, Washington; and ‖Department of Otolaryngology, Medical College of Wisconsin, Milwaukee, Wisconsin.
ASAIO J. 2017 Jul/Aug;63(4):392-400. doi: 10.1097/MAT.0000000000000503.
Treatment of end-stage heart failure includes cardiac transplantation or ventricular assist device (VAD) therapy. Although increasingly prevalent, current VAD therapy has inherent complications, including thrombosis. Studies have demonstrated that VAD implantation alters intracardiac blood flow, creating areas of stagnation that predispose to thrombus formation. Two potential surgical configurations exist for VAD implantation: through the apical or diaphragmatic surfaces of the heart. We hypothesized that diaphragmatic implantation causes more stagnation than apical implantation. We also hypothesized that intermittent aortic valve (AV) opening reduces stagnation of blood inside the left ventricle (LV) when compared with a closed AV. To test these hypotheses, a human LV geometry was recreated in silico and a VAD inflow cannula was virtually implanted in each configuration. A computational indicator-dilution study was conducted where "virtually dyed blood" was washed out of the LV by injecting blood with no dye. Simulations demonstrated a substantial reduction in stagnation with intermittent AV opening. In addition, virtual dye was cleared slightly faster in the apical configuration. Simulations from our study demonstrate the clinical importance of VAD management to allow intermittent opening of the AV to prevent subvalvular stagnation, and also suggests that apical configuration might be more hemodynamically favorable.
终末期心力衰竭的治疗方法包括心脏移植或心室辅助装置（VAD）治疗。尽管VAD治疗越来越普遍，但目前的VAD治疗存在一些固有并发症，包括血栓形成。研究表明，VAD植入会改变心腔内血流，形成易于血栓形成的血流停滞区域。VAD植入有两种潜在的手术方式：通过心脏的心尖或膈肌表面。我们假设膈肌植入比心尖植入会导致更多的血流停滞。我们还假设，与关闭主动脉瓣（AV）相比，间歇性主动脉瓣开放可减少左心室（LV）内的血液停滞。为了验证这些假设，我们在计算机上重建了人类左心室几何模型，并在每种方式下虚拟植入了VAD流入插管。进行了一项计算指示剂稀释研究，通过注入无染料的血液将“虚拟染色血液”从左心室冲洗出去。模拟结果表明，间歇性主动脉瓣开放可显著减少血流停滞。此外，在心尖植入方式下，虚拟染料清除得稍快一些。我们研究的模拟结果表明，VAD管理对于允许主动脉瓣间歇性开放以防止瓣下血流停滞具有临床重要性，并且还表明心尖植入方式在血流动力学方面可能更有利。
