| Research Abstract |
The direct vision by the specialized microscopic technique (using the apparatus which was offered by Grant-in-Aid) has enabled a real-timed observation of brain micro-circulatory disturbances under profoundly hypothermic cardiopulmonary bypass. After core cooling by cardiopulmonary bypass, non pulsatile low-flow perfusion, pulsatile low-flow perfusion, or circulatory arrest were performed. During non-pulsatile low-flow perfusion, blood sludgings with plasma skimming developped to microcirculatory collapses especially on the arteioles and venulse which were accompanied with dilatations of remnent vasculature. Moreover, inversion of flow direction developped frequently in the relatively large venous vasculatures(20-30 micron). After circulatory arrest, with infrequent blood sludgings,venous dilatations developped with and without collapses of neighboring venulae. These phenomena may be the real-timed dynamics of the "No-reflow phenomenon" which was showed by Norwood. On the other hand, pulsatile low-flow perfusion prevented these phenomena, or at least, made them slight and reversible. We will publish these results of direct observations, at first in the world, as "Brain microcirculatory disturbance during and after ischemia".
The results of brain tissue pH, P02, and PC02 , obtained by a support of Grant-in Aid of special project research(1985) were published in JJATS (1988), presented at the meeting of Japanese Association for Thoracic Surgery (1986,1988 both at Tokyo), in press in the journal of Thoracic and Cardiovascular Surgery (accepted May 10, 1988), and in review precess in the same journal. This research have proved the concept of these papers and presentations with obvious and convinving pictures, and have made the advantage of pulsatile low-flow perfusion for profound hypothermia more accurate. In the near future, biochemistric assesment will be added. And brain intra-cellular pH will be examined in the next research.
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