| Project/Area Number |
07457289
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Thoracic surgery
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| Research Institution | Fukui Medical School |
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Principal Investigator |
MURAOKA Ryusuke Fukui Medical School Professor, 医学部, 教授 (10026924)
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| Co-Investigator(Kenkyū-buntansha) |
KIMURA Tetsuya Fukui Medical School Assistant, 医学部, 助手 (50195369)
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| Project Period (FY) |
1995 – 1996
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| Project Status |
Completed (Fiscal Year 1996)
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| Budget Amount *help |
¥6,700,000 (Direct Cost: ¥6,700,000)
Fiscal Year 1996: ¥2,400,000 (Direct Cost: ¥2,400,000)
Fiscal Year 1995: ¥4,300,000 (Direct Cost: ¥4,300,000)
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| Keywords | circulatory arrest / cardiopulmonary bypass / brain ischemia / deep hypothermic inter mittent circulatory arrest / circulatory awest permission time / mitochondrial respiratory control index / brain edema / rear infrared spectrophotometer / 間歇的循環停止 / 超低体温 / 近赤外線分光法 / 嫌気性代謝 |
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| Research Abstract |
Deep hypothermic circulatory arrest is commonly used for thoracic aortic aneurysm and congenital heart disease. But circulatory arrest permission time is often a matter of some controversy. We examined possibility of extension of total circulatory arrest permission time by deep hypothermic intermittent circulatory arrest (DHICA). Twentyfive beagles were placed on cardiopulmonary bypass (CPB) at 100mL/kg/min.and cooled to 18ﾟC (DHT : deep hypothermia). The animals are kept DHT for 3 hours and divided into five groups. Group 1 : Uninterrupted CPB during DHT.Group 2 : 40 minutes of circulatory arrest (CA) during DHT.Group 3 : 60 minutes of CA during DHT.Group 4 : 80 minutes of CA during DHT.Group 5 : 20 minutes of CA following 10 minutes of recirculation repeating 6 times. Change of oxy-hemoglobin in brain tissue during CA was measured by near infrared spectrophotometer. In Group 2/3/4 oxy-hemoglobin was decreased sequentially with the onset of CA and became plateau at the mean time of 24.9(]SY.+-。[)1.2, that means oxy-hemoglobin could no longer supply oxygen to brain tissue. On the other hand, in Group 5, before oxy-hemoglobin became plateau, recirculation was begun, and oxy-hemoglobin recovered to prearrest value during ten minutes of recirculation. After the experiment period the animals are rewarmed to 35ﾟC and take brain tissue to measure mitochondrial respiratory index (RCI) and water content ratio. RCI of Group 4 was significantly lower than other Group (p<0.05). On the other hand, Group 5 keep good RCI while total circulatory arrest time was forty minutes longer than Group 4. Moreover, brain edema (that indicates index of brain edema) was significantly slighter in Group 5 than other Groups. These results suggest that DHICA can prolong total circulatory arrest permission time and DHICA can be a useful option when logn circulatory arrest is anticipated.
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