Research and clinical translation of trilayer stent-graft of expanded polytetrafluoroethylene for interventional treatment of aortic dissection

The aortic dissection(AD)is a life-threatening disease.The transcatheter endovascular aortic repair(EVAR)affords a minimally invasive technique to save the lives of these critical patients,and an appropriate stent-graft gets to be the key medical device during an EVAR procedure.Herein,we report a trilayer stent-graft and corresponding delivery system used for the treatment of the AD disease.The stent-graft is made of nitinol stents with an asymmetric Z-wave design and two expanded polytetrafluoroethylene(ePTFE)membranes.Each of the inner and outer surfaces of the stent-graft was covered by an ePTFE membrane,and the two membranes were then sintered together.The biological studies of the sintered ePTFE membranes indicated that the stent-graft had excellent cytocompatibility and hemocompatibility in vitro.Both the stent-graft and the delivery system exhibited satisfactory mechanical properties and operability.The safety and efficacy of this stent-graft and the corresponding delivery system were demonstrated in vivo.In nine canine experiments,the blood vessels of the animals implanted with the stent-grafts were of good patency,and there were no thrombus and obvious stenosis by angiography after implantation for 6months.Furthermore,all of the nine clinical cases experienced successful implantation using the stent-graft and its postrelease delivery system,and the 1-year follow-ups indicated the preliminary safety and efficacy of the trilayer stent-graft with an asymmetric Z-wave design for interventional treatment.