A magnetic device to eliminate endograft migration: theory and experiment

Endograft migration is a recognized problem in endovascular aneurysm repair, which may lead to aneurysm rupture, acute vessel thrombosis, or occlusion. This study presents a novel device to eliminate endograft migration that involves the use of a ferromagnetic stent graft (internal of vessel) and two magnetic rings (external to vessel, at the two necks of the stent). The magnetic rings (proximal and distal on the graft) with sufficient adhesion force were proposed to eliminate migration without overcompression of the aorta. Specifically, the objectives of the study are (1) to design the geometry and magnetic properties of the magnetic ring based on a mathematical model to produce the necessary tangential force to prevent endograft migration and (2) to validate the theoretical model with in vitro experiments. Our experimental results were in agreement with the numerical model, which showed feasibility of the approach to eliminate migration. This magnetic approach to eliminate endograft migration may lay the foundation for improvement of endograft repair of aortic aneurysm.