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Quantitative comparison of the dynamic flow waveform changes in 12 ruptured and 29 unruptured ICA-ophthalmic artery
Aichi Chien1, James Sayre, Fernando Viñuela
1Division of Interventional Neuroradiology, David Geffen School of Medicine at UCLA, 10833 LeConte Avenue, Box 951721, Los Angeles, CA 90095, USA. aichi@ucla.edu
Insights
Analyzing temporal blood flow changes in cerebral aneurysms reveals key differences between ruptured and unruptured cases. Flow waveform analysis offers insights beyond single time points for better understanding aneurysm rupture risk.
Area of Science:
- Biomedical Engineering
- Cardiovascular Research
- Neuroscience
Background:
- Limited research exists on dynamic cerebral aneurysm blood flow.
- Vascular diseases correlate with cardiac cycle blood flow dynamics.
- This study quantifies temporal flow changes in cerebral aneurysms.
Purpose of the Study:
- Investigate temporal blood flow changes within cerebral aneurysms during the cardiac cycle.
- Analyze flow waveforms in different aneurysm regions.
- Determine the association between flow dynamics and aneurysm rupture.
Main Methods:
- Simulated blood flow using patient-specific data from 12 ruptured and 29 unruptured internal carotid artery-ophthalmic artery aneurysms.
- Recorded temporal flow changes at various aneurysm locations.
- Compared flow waveforms between different regions and aneurysm types.
Main Results:
- Peak flow in aneurysm sacs often lagged behind parent artery peak flow (>60%).
- Aneurysm sacs exhibited higher pulsatility than parent arteries (P < 0.001).
- Ruptured aneurysms showed consistent high pulsatility; unruptured aneurysms showed increased pulsatility from neck to dome (P = 0.021).
- Significant inflow/outflow profile differences were observed in unruptured but not ruptured aneurysms (P = 0.023).
Conclusions:
- Temporal blood flow analysis provides crucial information beyond single time-point measurements.
- Flow waveforms reveal statistically significant differences between ruptured and unruptured aneurysms.
- Key differentiating factors include flow profile, pulsatility, and peak flow timing.
Introduction:
Studies have reported a correlation between blood flow dynamics in the cardiac cycle and vascular diseases, but research to analyze the dynamic changes of flow in cerebral aneurysms is limited. This quantitative study investigates the temporal changes in flow during a cardiac cycle (flow waveform) in different regions of aneurysms and their association with aneurysm rupture.
Methods:
Twelve ruptured and 29 unruptured aneurysms from the internal carotid artery-ophthalmic artery segment were studied. Patient-specific aneurysm data were implemented to simulate blood flow. The temporal flow changes at different regions of the aneurysm were recorded to compare the flow waveforms.
Results:
In more than 60 % of the cases, peak flow in the aneurysm sac occurred after peak flow in the artery. Flow rate varied among cases and no correlation with rupture, aneurysm flow rate, and aneurysm size was found. Higher pulsatility within aneurysm sacs was found when comparing with the parent artery (P < 0.001). Pulsatility was high throughout ruptured aneurysms, but increased from neck to dome in unruptured ones (P = 0.021). Significant changes between inflow and outflow flow profile were found in unruptured aneurysms (P = 0.023), but not in ruptured aneurysms.
Conclusion:
Quantitative analysis which considers temporal blood flow changes appears to provide additional information which is not apparent from aneurysmal flow at a single time point (i.e., peak of systole). By considering the flow waveform throughout the cardiac cycle, statistically significant differences were found between ruptured and unruptured cases - for flow profile, pulsatility and timing of peak flow.
