Microscopic assessment of healing and effectiveness of foam-based peripheral occlusion device

The IMPEDE® Embolization plug is a catheter-delivered vascular occlusion device that utilizes a porous shape memory polymer foam as a scaffold for thrombus blood clot formation, and distal coils to anchor the device within the vessel. In this study, we investigated the biological response of porcine arteries to the IMPEDE device by assessing the extent of healing and overall effectiveness in occluding the vessel at 30, 60, and 90 days. Compared to control devices (AmplatzerTM Vascular Plug and Nester® Embolization Coils), the host response to IMPEDE showed increased cellular infiltration (accommodated by the foam scaffold), which led to advanced healing of the initial blood clotthrombus to mature collagenous connective tissue (confirmed by TEM). Over time, the host response to the IMPEDE device included degradation of the foam by a multinucleated syncytiumgiant cells, which promoted fibrin and polymer degradation and advanced the healing response. Device effectiveness, in terms of vessel occlusion, was ev...