Design and verification of a shape memory polymer peripheral occlusion device

Abstract

Shape memory polymer foams have been previously investigated for their safety and efficacy in treating a porcine aneurysm model. Their biocompatibility, rapid thrombus formation, and ability for endovascular catheter-based delivery to a variety of vascular beds makes these foams ideal candidates for use in numerous embolic applications, particularly within the peripheral vasculature. This study sought to investigate the material properties, safety, and efficacy of a shape memory polymer peripheral embolization device in vitro. The material characteristics of the device were analyzed to show tunability of the glass transition temperature (Tg) and the expansion rate of the polymer to ensure adequate time to deliver the device through a catheter prior to excessive foam expansion. Mechanical analysis and flow migration studies were performed to ensure minimal risk of vessel perforation and undesired thromboembolism upon device deployment. The efficacy of the device was verified by performing blood flow studies that established affinity for thrombus formation and blood penetration throughout the foam and by delivery of the device in an ultrasound phantom that demonstrated flow stagnation and diversion of flow to collateral pathways.

Biodegradable shape memory polymer foams with appropriate thermal properties for hemostatic applications

“…Once actuated, the foam would expand and fill the wound. The combination of thrombogenic surface chemistry and high surface area‐to‐volume ratio results in rapid blood clotting within the foam (Landsman et al, ; Ortega, Hartman, Rodriguez, & Maitland, ). Previous in vivo studies demonstrated that SMP foams attain rapid blood clotting in a porcine hind limb vessel within 90 s (Rodriguez et al, ).…”

Effects of Sterilization on Shape Memory Polyurethane Embolic Foam Devices

“…As with cerebral aneurysms, embolization is a technique that is often utilized instead of an invasive surgery to block blood flow to specific anatomies. This treatment can be used to address a variety of morbidities, such as arteriovenous malformations (AVM), venous insufficiency, patent foramen ovales, or traumatic internal bleeding[32] Polyurethane SMP foams show promise for complete occlusion with a single device for any of the aforementioned conditions[4,33] [32]. SMP-based PEDs also contain a platinum/ iridium alloy anchor coil and marker band for device visualization under fluoroscopy[32].…”

Particulate Release From Nanoparticle-Loaded Shape Memory Polymer Foams

“…Additionally, their unique shape memory properties enable their catheter delivery through tortuous vasculature to the desired treatment site, where they expand to fill the site and promote clotting. Overall, these results combined with the positive prior in vivo study results indicate that the SMP foams present minimal risks from particulate release that may result in unintended downstream emboli formation and have high potential for use as effective and safe embolization devices [4,5,16,28].…”