Carotid Artery Constriction Model

Indication and Application

Evaluation of carotid artery stents and balloon expandable systems, efficacy testing of distal embolic protection devices (EPD / filter umbrellas), research on chronic cerebral hypoperfusion and vascular dementia, and validation of anti-thrombotic pharmacological interventions.

Modeling Method

• Large Animal Stenosis (Porcine/Canine): Under aseptic surgical conditions or endovascular monitoring, a calibrated external constrictor or Ameroid constrictor is positioned around the common carotid artery to achieve a specific percentage of luminal narrowing (typically 50% to 75% reduction), creating a stable model for interventional stent and EPD delivery.

• Rodent Hypoperfusion (Rats): Micro-cuffs or permanent surgical ligation are applied to the carotid arteries to construct specialized chronic cerebral hypoperfusion phenotypes (e.g., Two-Vessel Occlusion / 2-VO model).

Clinical Relevance

• Hemodynamic Fidelity: The localized constriction reliably reproduces the accelerated peak systolic velocity (PSV), downstream turbulence, and wall shear stress gradients that trigger clinical ischemic stroke and thromboembolic events.

• Device Deployment and Performance Platform: The physical geometry and vascular compliance of our large animal models precisely replicate human carotid bifurcation anatomy. This provides a high-fidelity platform to evaluate the radial strength of carotid stents and the particulate capturing efficiency of embolic protection filters.

Key Evaluation Endpoints

In Vivo / Surgical / Imaging:

• Color Doppler Ultrasound: Continuous non-invasive quantification of Peak Systolic Velocity (PSV), End-Diastolic Velocity (EDV), and real-time luminal diameter calculation to monitor stenosis severity.

• Digital Subtraction Angiography (DSA): Standardized angiography to verify residual stenosis percentages and assess device apposition post-stenting.

• Transcranial Doppler (TCD): Assessment of downstream cerebral blood flow velocities and embolic micro-signal detection.

Histopathology:

• Morphometry (Gold Standard): H&E and Verhoeff-Van Gieson (VVG) staining to measure internal elastic lamina (IEL) and external elastic lamina (EEL) areas, quantifying downstream intimal thickening and stenosis scores.

• Device-Tissue Interaction: Gross examination and resin embedded sectioning to assess endothelial coverage over stent struts and local inflammation.

• IHC/IF: Profiling of smooth muscle cells (alpha-SMA), endothelial layer integrity (CD31), and Macrophage markers (CD68) at the site of constriction.

Molecular:

• Analysis of oxidative stress makers and downstream cerebral ischemic tissue markers (e.g., HIF-1alpha, VEGF) via Western Blot or RT-qPCR to evaluate the systemic and regional neurovascular effects.