Acute, subacute, and long-term evaluation of a novel endovascular occlusion system in a large animal model.

ABSTRACT

OBJECTIVES: Endovascular occlusion of blood vessels represents a key component of interventional therapy. While coils are most commonly used, vessel occlusion is generally not achieved immediately and may necessitate a large number of devices. It has been suggested that endovascular plugs may overcome these limitations; however, immediate and durable occlusion remains a challenge with plugs as well. This study evaluates a newly designed endovascular occlusion system (EOS) METHODS: The EOS combines a nitinol coil with an impermeable membranous cap made of expanded polytetrafluoroethylene. The coil offers sufficient radial force to expand the membrane and minimize post-deployment migration. Fifteen test devices were deployed in the iliac (external and internal) and femoral arteries of five miniature swine, while two commercially available devices (platinum coils and a vascular plug) were used as controls in one miniswine. Angiography was performed 1, 5, and 10 minutes after device implantation. Follow-up angiography was obtained either on day 29 or day 61, prior to devices harvesting for histological evaluation and biocompatibility assessment. RESULTS: No clinical complications were observed in the animals throughout the study course. All test devices were deployed as intended, and produced complete and immediate vessel-occlusion. No recanalization or acute migration was observed within 10 minutes of deployment, whereas five test devices had migrated between 5 and 15 mm at follow-up angiography. Complete and durable vessel-occlusion without any sign of recanalization was observed in all EOS devices during the follow-up period. CONCLUSION: The EOS is a safe and reliable device resulting in immediate and durable vessel occlusion in the peripheral arterial circulation. While no device migration was observed in the pelvic area, it was observed with five test and one control devices in the vicinity of highly mobile articulations, leading to the conclusion that occlusion devices should not be placed within hypermobile areas such as the hip joint.