Question

Elaborate on various factors in determining both successful implantations, and vice-versa of Cook Zenith Alpha Thoracic Endovascular Graft?

Supposed that the failure of the device was due to the interaction of the biomaterial with biological tissues. So, as an expert in biomaterials, you are tasked to evaluate possible advancement in the field of nanomaterials that may reduce the risk of such device failure in future designs.

Answer 1

Zenith Alpha Thoracic Endovascular Graft

It is a two piece cylindrical endovascular graft consisting of proximal and distal component can be either tapered or nontapered and may be used independently or in combination with a distal component. The stent grafts are constructed of woven polyester fabric sewn to self expanding nitinol stents with braided polyester and monofilament polypropylene suture. Both components are fully stented to provide stability and the expansile force necessary to open the lumen of the graft during deployment. Additionally, the nitinol stents provide the necessary attachment and seal of the graft to the vessel wall. To assist with alignment the proximal component has an uncovered stent .For added fixation and sealing, the proximal component has an internal sealing stent with fixation barbs that protrude through the graft material . In addition , th ebare stent at the distal end of the distal component also contains barbs .On devices with diameters of 40-46mm, the proximal sealing stent remains constrained to ensure alignment with the inner curvature of the aorta. To facilitate fluoroscopic visualization of the stent graft, gold radiopaque markers are positioned on each end of the proximal and distal components. Gold markers are placed on stent apices at the proximal and distal aspects of the graft margins, denoting the edge of the graft material, to assist with deployment accuracy.