Development of a chronic endothelialized transcatheter implantable intra-aortic graft

The authors developed a new intraluminal aortic prosthesis (IA graft) for internal obliteration of Stanford type B dissection. The newly devised intraluminal aortic graft is a self-expandable metallic stent (Gianturco stent) outer-jacketed with a thin open-cell structured microporous film made of segmental polyurethane (0.2 mm thick, 0.1 mm pore size). Through the femoral artery, the intraluminal aortic grafts (14-20 mm diameter-, 4 cm long) were inserted into a 12 Fr catheter sheath by compression, were implanted into the descending thoracic aortas of five mongrel dogs; they were removed at the projected times of death ranging from 1 to 6 months after implantation. Histopathologic examination revealed that an elastic fiber layer had regenerated and that on the inner surface of the graft adherent and proliferating endothelial cells were observed, even at 1 month after graft implantation. Complete epithelialization was observed over the entire inner surface of the graft within 4 months after implantation. This healing process suggests that the intraluminal aortic graft is highly biocompatible and might be stable in chronic use after the obliteration of acute Stanford type B dissections.