In vivo observation of coronary microcirculation using a needle-probe video-microscope with a CCD camera during cardiac surgery

为了从形态学和功能上评价人体心肌微循环，我们研制了一种可用于心脏手术中冠状动脉微血管观察的带电荷耦合器件（CCD）摄像机的便携式针探针视频显微镜。首先，使用开胸麻醉的猪和狗，我们的目标是找到在手术中引入该系统的技术障碍。然后，我们开发了几件设备来克服方法上的问题。简而言之，为了避免针尖对微血管的直接压迫，开发了一种带有甜甜圈形状气球的鞘状针探针。为了在观察期间维持心肌微血管和周围组织的生理状态，研制了一种由热交换器和微管组成的系统，用于冲洗针尖和心肌之间的中间血液。使用这些装置，可以获得跳动心脏的心肌微血管图像，时间足够长，可以进行成像研究。此外，还研制了一种带CCD摄像机的便携式针探针视频显微镜的手持装置，使操作人员易于操作。这种保持装置有助于缩短观察时间。为了在没有任何特殊血管内造影剂的情况下显示心肌微血管，我们使用了绿色（红色的互补色）滤光片来加强充血血管和周围组织图像之间的对比度。这样，不仅可以看到冠状动脉，还可以看到冠状静脉。我们证实了携带CCD相机的便携式针状探针视频显微镜能够在使用所有这些支持系统的情况下可视化人类冠状动脉微血管。我们还评估了硝酸甘油微血管的作用。研究表明硝酸甘油扩张心外膜下和心内膜下的小动脉。还发现硝酸甘油扩张冠状静脉。

To evaluate the microcirculation of the human myocardium morphologically and functionally, we developed a portable needle-probe video-microscope with a charge coupled device (CCD) camera was applicable to the coronary microvessels during a cardiac surgery. First, using open-chest anesthetized pigs and dogs, we aimed to find technological hurdles for introducing the system during a surgery. Then, we developed several pieces of equipment to overcome the methodological problems. In brief, a sheathed needle-probe with a doughnut-shaped balloon was developed to avoid direct compression of the microvessels by the tip of the needle. To maintain a physiological condition of myocardial microvessels and the surrounding tissue during observation, a system consisting of a heat exchanger and a microtube was developed for flushing away the intervening blood between the tip of the needle and the myocardium. Using these devices, images of the myocardial microvessels of a beating heart could be obtained for a time which was long enough for imaging study. Furthermore, a holding device of the portable needle-probe video-microscope with a CCD camera was developed, which allowed an operator easy handling. This holding device contributed to shorten observation time. For the myocardial microvessels to be visualized without any special intravascular contrast medium, we employed a green (complimentary color of red) filter to accentuate the contrast between the images of the blood filled vessel and the surrounding tissue. Then, not only the coronary arterioles, but also coronary venules could be visualized. We confirmed that the portable needle-probe video-microscope with a CCD camera was able to visualize human coronary microvessels using all these supporting systems.We also evaluated the effects of nitroglycerin microvessels. The study showed that nitroglycerin dilates both subepicardial subendocardial arterioles. It was also found that nitroglycerin dilated coronary venules.