Kodai Sato

Publications (3)6.44 Total impact

• Article: ATP transport in saccular cerebral aneurysms at arterial bends.

  Yohsuke Imai, Kodai Sato, Takuji Ishikawa, Andrew Comerford, Tim David, Takami Yamaguchi
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  ABSTRACT: ATP acts as an extracellular signaling molecule in purinergic signaling that regulates vascular tone. ATP binds purinergic P2 nucleotide receptors on endothelial cells. Understanding the mass transport of ATP to endothelial cells by blood flow is thus important to predict functional changes in aneurysmal walls. While some clinical observations indicate a difference of wall pathology between ruptured and unruptured aneurysms, no study has focused on the mass transport in aneurysms. We investigated the characteristics of ATP concentration at aneurysmal wall using a numerical model of ATP transport in aneurysms formed at arterial bends. The magnitude of ATP concentration at the aneurysmal wall was significantly smaller than that at the arterial wall. In particular, significantly low concentration was predicted at the proximal side of the aneurysmal sac. A strong correlation was revealed between the inflow flux at the aneurysmal neck and the resultant concentration at the aneurysmal wall.
  Annals of biomedical engineering 12/2009; 38(3):927-34. · 2.41 Impact Factor
• Article: The importance of parent artery geometry in intra-aneurysmal hemodynamics.

  Kodai Sato, Yohsuke Imai, Takuji Ishikawa, Noriaki Matsuki, Takami Yamaguchi
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  ABSTRACT: We show the importance of arterial geometry in intra-aneurysmal hemodynamics. Using a new geometric parameterized saccular aneurysm model including parameters for parent artery shape and the configuration of the aneurysm in the parent artery, we performed a parametric computational fluid dynamics study. We examined lateral saccular aneurysm models with different aneurysm shapes (i.e., the ratio of aneurysm height to aneurysm neck diameter) and different configurations (i.e., the torsion angle of the aneurysm to the upstream part of the parent artery). The aneurysm lateral to the curve of the parent artery had significantly higher wall shear stress than the aneurysm inside or outside the curve of the artery, even with the same shape of the aneurysm. Our findings suggest the important role played by the configuration of the aneurysm relative to the parent artery in intra-aneurysmal hemodynamics.
  Medical Engineering & Physics 08/2008; 30(6):774-82. · 1.62 Impact Factor
• Article: Inflow into saccular cerebral aneurysms at arterial bends.

  Yohsuke Imai, Kodai Sato, Takuji Ishikawa, Takami Yamaguchi
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  ABSTRACT: To identify shortcomings in the design of conventional endovascular devices, we investigated the inflow features of untreated aneurysms at a variety of arterial bends using computational fluid dynamics. As a preliminary study, we analyzed the steady-state inflow for aneurysms created at U-shaped, twisted, and S-shaped arteries. Both the inflow pattern and inflow flux were strongly influenced by the shape of the artery and the configuration angle of the aneurysm to the artery. We revealed that the secondary flow generated in the parent artery is the dominant factor affecting the inflow. Our results suggest that the arterial geometry and secondary flow should be considered in the design of endovascular devices.
  Annals of biomedical engineering 07/2008; 36(9):1489-95. · 2.41 Impact Factor