Wall Shear Stress and T1 Contrast Ratio Are Associated With Embolic Signals During Carotid Exposure in Endarterectomy.

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K10737
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Neurosurgery
• Research Institution: Iwate Medical University
• Principal Investigator: Kobayashi Masakazu 岩手医科大学, 医学部, 助教 (60364345)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 数値流体解析 / 壁せん断応力 / 高磁場MRI / プラークイメージ / 経頭蓋ドップラ / 頚動脈狭窄 / 頚動脈内膜剥離術 / 微小塞栓

Outline of Final Research Achievements

The present study were to determine whether wall shear stress(WSS) calculated using computational fluid dynamics(CFD) analysis for carotid arteries is associated with development of embolism during exposure of carotid arteries during carotid endarterectomy (CEA). 54 patients with internal carotid artery (ICA) stenosis due to a vulnerable plaque showing high intensity on magnetic resonance (MR) imaging underwent cervical 3-dimentional MR angiography, and the maximum value of WSS of the ICA was calculated. Transcranial Doppler monitoring of microemboli(ME) in the ipsilateral artery was performed during CEA. ME during exposure of carotid arteries were detected in 24 patients. Multivariate statistical analysis showed that higher plaque intensity and higher WSS were significantly associated with the development of MES.
WSS calculated using CFD analysis for carotid arteries is associated with development of embolism during exposure of ICA during CEA in patients with vulnerable plaques.

Free Research Field

医学

Academic Significance and Societal Importance of the Research Achievements

頚部頚動脈狭窄症に対する頚動脈内膜剥離術（CEA）は、脳梗塞の発症及び再発予防として有効な治療法である。適応として周術期合併症発生頻度が一定基準以下である事が必須であり、合併症発生の術前予測は重要である。頚動脈露出操作中に経頭蓋ドップラで検出される術中微小塞栓（ME）は、周術期脳合併症の過半数を占める脳塞栓症と相関する為、ME出現の術前予測精度の向上が重要である。本研究は、血管腔内の血流の影響とME出現との関係を明らかにし、壁せん断応力とプラーク信号比の二項目がME出現に関わる有意な独立因子である事を証明した。プラーク性状と血流は異なるメカニズムでME出現に関与している可能性が示唆された。