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[Clinical study and numerical simulation of hemodynamics in the tortuosity of internal carotid artery].

OBJECTIVES
To establish a theoretical model for the tortuosity of internal carotid artery and summarize the hemodynamic rule of blood flow in a tortuous artery. To explore the relationship of cerebral ischemia and tortuous internal carotid artery.


METHODS
Taking the internal carotid artery as a prototype, a geometric model of a tortuous artery was constructed according to the normal physiological and anatomical parameters of internal carotid artery. The boundary conditions and calculation conditions of blood flow are proposed. The numerical simulation of the blood flow in the tortuous artery is carried out with finite element method. Hemodynamic parameters of internal carotid artery were measured in 15 cases with the tortuosity of internal carotid artery and in 15 cases of normal control group. Blood pressure was measured by microcatheter connecting a pressure transducer at internal carotid artery, pre-tortuous and post-tortuous artery. The diameter and length of the above artery were measured and calculated by DSA machine.


RESULTS
Numerical simulation results indicated pressure drop of blood flow and elongated length of artery is increased with diminution of the angle of tortuous artery. Clinical measurement data disclosed the same trend in the same curve as numerical simulation.


CONCLUSION
The elongation and tortuosity of internal carotid artery results in decrease of blood pressure in the distal segment of tortuous internal carotid artery, kinking of internal carotid artery may be one of factors related to attack of cerebral ischemia on certain conditions.