Computational Fluid Dynamics Analysis of Cerebrovascular Hemodynamic Differences in Adults with Sickle Cell Disease:
Lara Abdelmohsen1, Anyssa Oden1, Tamer S Ibrahim2
1Department of Biomedical Engineering, Carnegie Mellon University, 346 Hamerschlag Dr, Pittsburgh, 15213, PA, USA.
Insights
Adult sickle cell disease (SCD) patients show distinct cerebral blood flow patterns. These hemodynamic differences in the Circle of Willis may help predict stroke risk and guide future adult stroke prevention strategies.
Area of Science:
- Neurology
- Cardiovascular Science
- Biomedical Engineering
Background:
- Sickle cell disease (SCD) poses a lifelong risk of cerebrovascular disease, particularly stroke, affecting patients from childhood to adulthood.
- Current stroke prevention guidelines, like those using transcranial Doppler ultrasound (TCD), are limited to pediatric populations, creating a critical gap for adult SCD patients.
- Understanding cerebral hemodynamics in the Circle of Willis (CoW) is crucial for developing effective risk stratification and treatment strategies for adults with SCD.
Purpose of the Study:
- To characterize the cerebral hemodynamic differences in the Circle of Willis (CoW) of adult patients with sickle cell disease (SCD).
- To provide data supporting the development of future stroke risk stratification and personalized treatment guidelines for adults with SCD.
- To investigate how cerebrovascular disease and stroke impact cerebral blood flow dynamics in the CoW.
Main Methods:
- Utilized patient-specific, 3D vascular geometries derived from high-resolution magnetic resonance imaging for numerical simulations.
- Included three groups: healthy controls (n=3), SCD patients without a history of stroke (n=3), and SCD patients with a history of stroke (n=3).
- Quantified key hemodynamic parameters: time-averaged wall shear stress (TAWSS), surface area exposed to low/high WSS, time-averaged mean of maximum velocity (TAMMV), and pressure drop across the CoW.
Main Results:
- SCD patients post-stroke exhibited lower TAMMV at TCD-equivalent CoW locations and the lowest average TAWSS, with the largest area exposed to low WSS (<1 Pa).
- SCD patients without stroke showed the highest TAWSS and the greatest area exposed to high WSS (>7 Pa).
- Despite comparable total cerebral blood flow to controls, post-stroke patients demonstrated a reduced pressure drop across the CoW.
Conclusions:
- Patient-specific computational fluid dynamics simulations effectively quantify cerebral hemodynamics in adults with SCD.
- The study reveals distinct hemodynamic alterations associated with stroke in adult SCD patients.
- Findings can inform future stroke risk assessment and the development of personalized treatment strategies for this population.
Purpose:
Sickle cell disease (SCD) is a debilitating genetic disorder affecting hemoglobin in red blood cells. Patients with SCD are at risk of cerebrovascular disease in the Circle of Willis (CoW), with strokes occurring from early childhood into adulthood. Despite this lifelong risk, stroke prevention guidelines using transcranial Doppler ultrasound (TCD) exist only for children, leaving a critical gap for adults. This study aimed to characterize cerebral hemodynamics in the CoW of adults with SCD to support future risk stratification and treatment guidelines.
Methods:
Numerical simulations were performed using 3D vascular geometries segmented from high-resolution, patient-specific magnetic resonance imaging in healthy controls (n=3), SCD patients without stroke (n=3), and SCD patients post-stroke (n=3). Key hemodynamic parameters including time-averaged wall shear stress (TAWSS), surface area exposed to low or high WSS, time-averaged mean of maximum velocity (TAMMV), and pressure drop across the CoW were quantified and compared.
Results:
Preliminary results show distinct hemodynamic differences were observed across groups. SCD patients post-stroke had lower TAMMV at TCD-equivalent CoW locations (except one with ICA stenosis), the lowest average TAWSS, and the greatest surface area exposed to WSS Pa. In contrast, SCD patients without stroke had the highest TAWSS and greatest area exposed to WSS >7 Pa. Despite similar total cerebral blood flow to controls, post-stroke patients showed a lower pressure drop across the CoW.
Conclusions:
Patient-specific simulations can quantify cerebral hemodynamics in adults with SCD, offering insight into stroke-related changes and informing future stroke risk assessment and personalized treatment strategies.
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