Spatio-temporal changes and migration of stent grafts after endovascular aortic aneurysm repair

In this paper we present an approach to analyse the migration of stent grafts after endovascular aortic aneurysm repair. Stent graft migration and kinking or buckling of the graft can cause the perilous risk of rupture. Our approach allows describing the occurring movements quantitatively towards the aim to find common patterns related to different endograft devices or to dangerous changes in morphology. We proceed by defining the spinal canal as reference system and by investigating the movements of the graft relative to it. Here, we segment the spinal canal as well as the stent graft at different time points and we apply a point set registration algorithm in order to calculate the transformation to the spinal canal reference system and to determine the occurring motion of the stent. First results illustrate that essentially rigid motion occurs in case of thoracic aortic aneurysms.