Branched stent grafts for endovascular repair of the aortic arch: a work in progress

As a site for endovascular aneurysm repair, the aortic arch is challenging and unforgiving. Surgical repair, under hypothermic circulatory arrest, and hybrid debranching operations both leave considerable room for improvement. Nevertheless, endovascular methods of arch repair, involving the use of branched stent grafts, have developed less rapidly than similar methods of thoracoabdominal repair. The explanation lies in the unique anatomy of the aortic arch, which is wide, curved, far from the femoral arteries, and close to the aortic valve. Investigators have tried a wide variety of branched endovascular stent grafts, ranging from complex multi-branched unibody designs to simple bifurcated modular designs. None has been entirely satisfactory. At this point, the largest experience involved transcarotid implantation of a long leg/short leg bifurcated stent graft. This approach provides technical solutions to several technological problems, such as delivery system caliber, flexibility, and torquability. However, real progress in this field has had to wait on changes in the technology itself. The advent of low-profile stent grafts and delivery systems will likely result in a shift away from transcervical insertion in favor of transfemoral insertion, and away from adjunctive bypass between supra-aortic trunks in favor of multi-branched modular systems. It is no coincidence that endovascular repair of the aortic arch is coming to resemble endovascular repair of the thoracoabdominal aorta where the combination of a cuff-bearing aortic stent graft and covered stents has proven to be safe, effective, and durable.