Endovascular repair of the aortic arch.

The aortic arch is a challenging site for endovascular repair. The proximal implantation site is often wide, angulated, conical, and limited in length by the presence of vital branches to the head and arms. The only way to lengthen the implantation site without risking stroke is to provide an alternative source of inflow through endovascular or extravascular bypass. The complexity and stroke risk of branched stent-graft implantation increases exponentially with each additional branch. In our opinion, the safest strategy is to limit the stent graft to a single side branch. This bifurcated stent graft requires multiple bypass grafts in the neck but avoids median sternotomy and partial aortic clamping. Stent-graft implantation through the carotid or innominate artery provides a short, straight route to the proximal ascending aorta and ensures simple accurate placement of the innominate limb. In our experience, the primary limitation has been the anatomy of the ascending thoracic aorta, which may be too short or too wide. Previously created coronary bypass grafts (if patent) may also prevent proximal stent-graft implantation. The bypass grafts and route of access through the neck and groin are created using standard surgical techniques. Both components of the stent graft are implanted during brief periods of cardiac standstill. The tip of the bifurcated stent-graft delivery system is introduced over a curved guidewire into the left ventricle. Otherwise, the endovascular techniques of bifurcated arch repair are essentially those of bifurcated abdominal aortic repair. Despite high flows and wide-diameter components, current experience has shown bifurcated stent grafts of this type to be stable with follow-up over 3 years.