Novel Human Acute Ischemic Stroke Blood Clot Analogs for In Vitro Thrombectomy Testing

Area of Science:

• Biomedical Engineering
• Hematology
• Medical Device Testing

Background:

• Previous studies utilized animal blood for clot analogs, which may not accurately reflect human thrombi due to species-specific blood component variations.
• Accurate in vitro models are crucial for testing endovascular devices used in treating conditions like acute ischemic stroke.

Purpose of the Study:

• To develop and characterize in vitro clot analogs using human blood components.
• To evaluate the performance of thrombectomy devices using these human-derived clot analogs with varying mechanical properties.

Main Methods:

• Human whole blood and platelets were obtained and processed into twelve clot analogs with diverse red blood cell, fibrin, and platelet compositions.
• Coagulation was stimulated using thrombin and calcium chloride.
• Histologic and immunohistochemical staining assessed clot composition.
• Three types of clot analogs (soft, elastic, stiff) were selected for in vitro thrombectomy testing.

Main Results:

• The created clot analogs exhibited a wide range of compositions (RBC: 8.9–91.4%, Fibrin: 3.1–53.4%, Platelets: 0.5–47.1%) representative of clinical thrombectomy retrievals.
• Soft clots demonstrated the highest first-pass effect and revascularization rates.
• Stiff clots showed the highest incidence of distal embolization due to weak clot/device integration.

Conclusions:

• In vitro clot analogs mimicking patient clots (red blood cell-rich, fibrin-rich, platelet-rich) were successfully created using human blood.
• Thrombectomy testing confirmed that clot analog composition influences retrieval outcomes and device performance.