Fujiwara Tatsuki, Sakota Daisuke, Ohuchi Katsuhiro, Endo Shu, Tahara Tomoki, Murashige Tomotaka, Kosaka Ryo, Oi Keiji, Mizuno Tomohiro, Maruyama Osamu, Arai Hirokuni
Department of Cardiovascular Surgery, Tokyo Medical and Dental University Graduate School of Medical and Dental Sciences.
Health Research Institute, National Institute of Advanced Industrial Science and Technology (AIST).
Artif Organs. 2017 Oct;41(10):893-903. doi: 10.1111/aor.12862. Epub 2017 Mar 20.
Complications due to pump thrombus remain the weak point of mechanical circulatory support (MCS), such as the use of a left ventricular assist device (LVAD) or extracorporeal membrane oxygenation, leading to poor outcomes. Hyperspectral imaging (HSI) is an effective imaging method using a hyperspectral (HS) camera, which comprises a spectrophotometer and a charge-coupled device camera to discriminate thrombus from whole blood. Animal experiments were conducted to analyze dynamic imaging of thrombus inside a prototype of a hydrodynamically levitated centrifugal blood pump using an HSI system. Six pigs were divided into a venous circulation group (n = 3) and an arterial circulation group (n = 3). Inflow and outflow cannulae were inserted into the jugular veins in the venous circulation group. The latter simulated an LVAD application. To create thrombogenic conditions, pump flow was maintained at 1 L/min without anticoagulation. An image of the bottom surface of the pump was captured by the HS camera every 4 nm over the wavelength range of 608-752 nm. Real-time dynamic images of the inside of the pump were displayed on the monitor. Appearance of an area displaying thrombus was detected within 24 h after the start of the circulation in every experiment. This imaging system also succeeded in determining the origins of pump thrombus: from inside the pump in two cases, and from outside in four cases. Two main possible sources of pump thrombus originating outside the pump were identified on autopsy: wedge thrombus around the inflow cannula; and string-like thrombus at the junction between the pump inlet and circuit tube. The results of this study from close observation of the changing appearance of pump thrombus may contribute to improvements in the safety of extracorporeal MCS.
泵血栓引起的并发症仍然是机械循环支持（MCS）的薄弱环节，例如使用左心室辅助装置（LVAD）或体外膜肺氧合，会导致不良后果。高光谱成像（HSI）是一种使用高光谱（HS）相机的有效成像方法，该相机由分光光度计和电荷耦合器件相机组成，用于区分血栓和全血。进行了动物实验，以使用HSI系统分析一种流体动力学悬浮离心血泵原型内部血栓的动态成像。将六头猪分为静脉循环组（n = 3）和动脉循环组（n = 3）。静脉循环组将流入和流出插管插入颈静脉。后者模拟LVAD的应用。为了创造血栓形成条件，在不进行抗凝的情况下将泵流量维持在1 L/min。在608-752 nm波长范围内，每隔4 nm用HS相机拍摄一次泵底面的图像。泵内部的实时动态图像显示在监视器上。在每个实验中，循环开始后24小时内检测到显示血栓的区域出现。该成像系统还成功确定了泵血栓的起源：两例来自泵内部，四例来自外部。尸检时确定了泵外部起源的泵血栓的两个主要可能来源：流入插管周围的楔形血栓；以及泵入口与回路管连接处的串状血栓。这项对泵血栓外观变化进行密切观察的研究结果可能有助于提高体外MCS的安全性。
