| Project/Area Number |
12671649
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Otorhinolaryngology
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| Research Institution | CHIBA UNIVERSITY |
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Principal Investigator |
NUMATA Tsutomu Chiba university, Graduate school of medicine, Associate professor, 大学院・医学研究院, 助教授 (60189355)
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| Co-Investigator(Kenkyū-buntansha) |
HIRUMA Kiyoshi Chiba university, University Hospital, Assistant, 医学部・附属病院, 助手 (30301097)
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| Project Period (FY) |
2000 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥3,200,000 (Direct Cost: ¥3,200,000)
Fiscal Year 2001: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 2000: ¥1,800,000 (Direct Cost: ¥1,800,000)
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| Keywords | transcranial Doppler method / cerebral hemodynamics / carotid artery resection / 経頭蓋骨的超音波ドプラ法 / 頚動脈切除 / 経頭蓋骨的ドプラ法 / 内頸動脈切除 / 脳血流自動調節能 |
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| Research Abstract |
We studied dynamic cerebrovascular autoregulation in the patients who had undergone unilateral carotid artery resection using ultrasonic transcranial Doppler method (TCD). The correlation between the flow velocity of the middle cerebral artery (FV_<MCA>) and the cerebral perfusion pressure (CPP) was investigated. CPP was calculated from the systemic arterial blood pressuure adjusted to the level of MCA (ABP_<MCA>) and the critical closing pressure (CCP), which was estimated from the systolic-diastolic relationship between FV_<MCA> and ABP_<MCA>. CCP demonstrates the arterial pressure below which blood flow stops within the MCA. Initially we studied dynamic cerebrovascular responses in eight healthy humans during repetitive stepwise upward tilt and downward tilt. The results of the study indicated that FV_<MCA> was changed in accordance with the changes of CPP, which was changed in accordance to the change of CCP. Next we studied post-operative changes of cerebral hemodynamics after unilateral internal carotid artery resection in four patients. FV_<MCA> recovered within 1-2 days after internal carotid artery resection. CPP was raised not because ABP_<MCA> elevated but CCP was markedly lowered in 1-2 days, after surgery. Interception of internal jugular/vein of these patients elevated CCP and lowerd FV_<MCA> resticting the dynamic cerebrovascular autoregulation of patients with unilateral carotid artery resection within a small range. From the results of this reserch, FV_<MCA> was maintained mainly by lowered CCP in patients with carotid artery resection. Reconstruction of artery which raise ABP_<MCA> and reconstruction of internal jugular vein which lowers CCP will improve the cerebral blood flow in those patients with insufficient dynamic cerebrovascular autoregulation.
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