Internal Carotid Artery Aneurysms And The Correlation Between Internal Carotid Artery Tortuosity And Hemodynamics

Objective:To evaluate the correlation between the internal carotid artery(ICA)aneurysm and ICA tortuosity and hemodynamics.Methods:Retrospective analysis was performed on 176 patients with unilateral ICA aneurysms confirmed by CTA.The tortuosity index(TI)of both aneurysmal and non-aneurysmal ICAs were measured,tortuosity index of extra-cranial and intra-cranial segment of the ICA were indicated as TIA and TIB respectively.And the hemodynamic parameters including wall shear stress(WSS),oscillatory shear index(OSI)and percentage of low wall shear stress area(LSA)of bilateral ICA were calculated by computer fluid dynamics(CFD)software.Comparison between TI and hemodynamic parameters of aneurysmal and non-aneurysmal ICA was made to determine whether there’s an association between the ICA aneurysm and ICA tortuosity and hemodynamics.Results:TIA and TIB were higher in patients aged 55 years or older,obese or hypertensive.Both TIA and TIB on the aneurysm side were significantly higher than those on the non-aneurysm side,and the difference of TIB was more obvious.We didn’t find significant difference in TIA between large and small aneurysms,but TIB for large aneurysms was higher than TIB for small aneurysms.There were no significant difference in TIA and TIB between wide-necked and narrow-necked aneurysms,ruptured and un-ruptured aneurysms.WSS and LSA on the aneurysm side were significantly higher than those on the non-aneurysm side,and the difference of OSI between the aneurysm side and the non-aneurysm side wasn’t statistically significant.WSS and LSA of high tortuous ICAs were also significantly higher than those of low tortuous ICAs,The difference of OSI between those wasn’t statistically significant.Conclusion:ICA tortuosity is higher in older,obese,and hypertensive patients with ICA aneurysms.The tortuosity of the ICA,especially the tortuosity of the intracranial segment of the ICA was significantly correlated with the ICA aneurysm,but the tortuosity of the ICA had nothing to do with the rupture state and size of the ICA aneurysm.The ICA on the aneurysm side had higher WSS and LSA than that on the non-aneurysm side,and the ICA with higher tortuosity had higher WSS and LSA than those with lower tortuosity,which may be the potential reason for the high correlation between ICA tortuosity and ICA aneurysm.