A novel in vitro method for assessing the resistance to distal displacement of endovascular stent grafts for abdominal aortic aneurysm repair

Abstract

Migration of endovascular stent grafts for abdominal aortic aneurysm (AAA) is a serious complication that can result in aneurysm sac repressurisation and rupture. Secure fixation of stent-grafts in the proximal neck and the iliac legs is crucial to prevent this complication. We outline an in vitro method of investigating the resistance to migration of both a commercially available (AneuRx, Medtronic, Santa Rosa, Ca, USA) and homemade device. The devices were implanted in a silicone rubber mock AAA model and subjected to physiological pulsatile flow. The fixation strength of the AneuRx device was 8.52±0.5N and the fixation force for the homemade stent-graft was 4.62±0.25N. These results highlight the importance of longitudinal strength in devices without hooks or barbs on the proximal stent.