Computational study of clot formation in aneurysms treated with shape memory polymer foam

Area of Science:

• Biomedical Engineering
• Medical Devices
• Computational Modeling

Background:

• Intracranial aneurysms are treated with endovascular metal coils to induce thrombus formation and isolate the aneurysm.
• Current coil embolization can lead to suboptimal outcomes and aneurysm recurrence.
• Shape memory polymer foam is a novel alternative filler material for aneurysm treatment.

Purpose of the Study:

• To computationally predict and compare thrombus formation in aneurysms treated with shape memory polymer foam versus traditional metal coils.
• To evaluate the impact of foam properties (pore size, orientation) on clotting efficacy.
• To assess the predictability and uniformity of clot formation for each treatment method.

Main Methods:

• Utilized a computational thrombus model to simulate clotting within idealized 2D aneurysms.
• Modeled aneurysms treated with virtual shape memory polymer foam.
• Compared simulation results to previously reported data for endovascular metal coil treatments.

Main Results:

• Foam-filled aneurysms achieved at least 94% thrombus occlusion, irrespective of foam pore size or orientation.
• Coil-filled aneurysms showed variable thrombus occlusion (80.8% to 92.2%), often with incomplete neck filling.
• Shape memory polymer foam demonstrated more uniform and complete clotting compared to metal coils.

Conclusions:

• Shape memory polymer foams show potential for more predictable and complete aneurysm occlusion than bare metal coils.
• Foam-based embolization appears less dependent on geometric factors like pore size and orientation for efficacy.
• This suggests polymer foams may offer improved clinical outcomes in aneurysm treatment.