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

• 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
• Project Status: Completed (Fiscal Year 2018)
• Budget Amount: ¥4,550,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥1,050,000); Fiscal Year 2018: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000); Fiscal Year 2017: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000); Fiscal Year 2016: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
• 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 / 頚部内頚動脈狭窄 / 頚動脈内膜摘出術 / 脳血管障害 / 数値流体力学 / 超高磁場MRI / 頚動脈 / CEA / MES / CFD

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.

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。

Research Products

• [Journal Article] Impact of external carotid artery occlusion at declamping of the external and common carotid arteries during carotid endarterectomy on development of new postoperative ischemic cerebral lesions. (2019)
  • Author(s): Kobayashi M., Yoshida K., Kojima D., Oshida S., Fujiwara S., Kubo Y., Ogasawara K.
  • Journal Title: J Vasc Surg. Volume: 69(2) Issue: 2 Pages: 454-461
  • DOI: 10.1016/j.jvs.2018.03.437
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Wall Shear Stress and T1 Contrast Ratio Are Associated With Embolic Signals During Carotid Exposure in Endarterectomy (2018)
  • Author(s): Oshida Sotaro、Mori Futoshi、Sasaki Makoto、Sato Yuiko、Kobayshi Masakazu、Yoshida Kenji、Fujiwara Shunrou、Ogasawara Kuniaki
  • Journal Title: Stroke Volume: 49 Issue: 9 Pages: 2061-2066
  • DOI: 10.1161/strokeaha.118.022322
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Preoperative brain temperature imaging on proton magnetic resonance spectroscopy predicts hemispheric ischemia during carotid endarterectomy for unilateral carotid stenosis with inadequate collateral blood flow. (2018)
  • Author(s): Tsutsui S, Nanba T, Yoshioka Y, Sasaki M, Fujiwara S, Kobayashi M, Yoshida K, Miyoshi K, Sato S, Ogasawara K.
  • Journal Title: Neurol Res. Volume: 30 Pages: 1-7
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Preoperative Cerebral Oxygen Extraction Fraction Imaging Generated from 7T MR Quantitative Susceptibility Mapping Predicts Development of Cerebral Hyperperfusion following Carotid Endarterectomy. (2017)
  • Author(s): Nomura JI, Uwano I, Sasaki M, Kudo K, Yamashita F, Ito K, Fujiwara S, Kobayashi M, Ogasawara K.
  • Journal Title: AJNR Am J Neuroradiol. Volume: 38(12) Issue: 12 Pages: 499-505
  • DOI: 10.3174/ajnr.a5390
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Preoperative cervical carotid artery contrast-enhanced ultrasound findings are associated with development of microembolic signals on transcranial Doppler during carotid exposure in endarterectomy. (2017)
  • Author(s): Oikawa K, Kato T, Oura K, Narumi S, Sasaki M, Fujiwara S, Kobayashi M, Matsumoto Y, Nomura JI, Yoshida K, Terayama Y, Ogasawara K.
  • Journal Title: Atherosclerosis Volume: 260 Pages: 87-93
  • DOI: 10.1016/j.atherosclerosis.2017.03.026
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Optimal MR Plaque Imaging for Cervical Carotid Artery Stenosis in Predicting the Development of Microembolic Signals during Exposure of Carotid Arteries in Endarterectomy: Comparison of 4 T1-Weighted Imaging Techniques. (2016)
  • Author(s): Sato Y, Ogasawara K, Narumi S, Sasaki M, Saito A, Tsushima E, Namba T, Kobayashi M, Yoshida K, Terayama Y, Ogawa A.
  • Journal Title: AJNR Am J Neuroradiol. Volume: 37 Issue: 6 Pages: 1146-54
  • DOI: 10.3174/ajnr.a4674
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Presentation] 頚動脈内膜剥離術中の外頚・総頸動脈遮断解除時における医原性外頚動脈閉塞は術後虚血病巣出現のリスクである (2019)
  • Author(s): 小林正和、吉田研二、小島大吾、大志田創太郎、藤原俊朗、久保慶高、小笠原邦昭
  • Organizer: 第４４回日本脳卒中学会学術集会
• [Presentation] 脆弱性プラークにおける数値流体力学解析を用いた頚動脈内膜剥離術中微小塞栓出現の術前予測 (2018)
  • Author(s): 大志田創太郎、森太志、佐々木真理、佐藤由衣子、小林正和、吉田研二、藤原俊朗、小笠原邦昭
  • Organizer: 第４７回日本脳卒中の外科学会学術集会
• [Presentation] 脆弱性プラークにおける数値流体力学解析を用いた頚動脈内膜剥離術中微小塞栓出現の術前予測 (2018)
  • Author(s): 大志田創太郎、森太志、佐々木真理、佐藤由衣子、小林正和、吉田研二、藤原俊朗、小笠原邦昭
  • Organizer: 一般社団法人日本脳神経外科学会第７７回学術総会
• [Presentation] 頚動脈内膜剥離術中の外頚・総頸動脈遮断解除時における医原性外頚動脈閉塞は術後虚血病巣出現のリスクである (2018)
  • Author(s): 小林正和、吉田研二、小島大吾、大志田創太郎、藤原俊朗、久保慶高、小笠原邦昭
  • Organizer: 一般社団法人日本脳神経外科学会第７７回学術総会
• [Presentation] 頚動脈内膜剥離術中の外頚・総頚動脈遮断解除時における医原性外頚動脈閉塞は術後脳虚血病巣出現のリスクである (2018)
  • Author(s): 小林正和、吉田研二、小島大吾、吉田純、島田泰良、久保慶高、藤原俊朗、小笠原邦昭
  • Organizer: 第27回脳神経外科手術と機器学会