Pulsatility index in internal carotid artery tortuosity

Background and aims: Shear stress is suggested as one of the mechanism that can cause arterial tortuosity. Pulsatility index (PI) is associated with local shear stress. This study aimed to describe the PI in tortuous internal carotid artery (ICA).
Methods: This was a retrospective descriptive cross sectional study using the registry of Neurology outpatient clinic, Dr. Cipto Mangunkusumo National Central General Hospital, Jakarta, Indonesia, from January to December 2020. We evaluated the characteristic of subjects with tortuous internal carotid artery according to carotid Doppler examination. Univariate analysis, Chi-Square and Independent T-test were performed to evaluate difference statistically.
Results: There were 129 subjects with mean age of 58 ± 11.22 years. The proportion of ICA tortuosity was 23.2% (30/129). The frequency of tortuous internal carotid artery was significantly higher in women than men (40.8% vs 13.8%) and dyslipidemia versus non dyslipidemia subjects (40.8% vs. 13.8%). Mean of PI, PSV, EDV in tortuous ICA were 1.18 ± 0.30, PSV ICA 73.5 ± 26.6 cm/s, and EDV ICA 24.4 ± 8.5 cm/s, consecutively. There was no mean difference of PI ICA between tortuous and non-tortuous subjects (1.18 ± 0.30 vs. 1.2 ± 0.35, p = 0.43).
Conclusions: The pulsatility index of tortuous ICA was not significantly different compared to non-tortuous subjects. Therefore, vascular risk seemed to have no evidence causing tortuous internal carotid artery in this study.