Implication of thoracic aortic stent-graft conformability on clinical outcomes

Endovascular management concepts have recently emerged as valuable treatment options for both simple and complex disorders involving both the distal arch and descending thoracic aorta. With growing use of endovascular stent-grafts the technique has generated broad interest. Nevertheless, an ideal device for different thoracic aortic conditions is not available yet. After initially using the first-generation or "home-made" thoracic stent-grafts with its relative rigidity and considerable diameter of the delivery system, recent advances have generated more flexible and conformable second- and third-generation stent-grafts. Nonetheless, challenges of providing optimal conformability and better fixation in the aortic arch and thoracic aorta are substantial, given the spiralling motion of the thoracic aorta with each ventricular contraction. Ultimately, the capacity of thoracic stent-graft to appose tightly to the aortic wall not only ensures effective sealing and fixation, but also avoids endoleaks and migration, graft stability and thus overall successful repair with aortic remodeling. Conformability is therefore the combined effect of apposition to the thoracic aortic anatomy, and kink-resistant flexibility of the stent-graft.