Exclusion of Lumbar Arteries by Aortic Endovascular Grafts: Can Angiography Demonstrate Sealing Characteristics?

Abstract

Background: This study evaluates sealing characteristics of two designs of endovascular grafts by angiographic demonstration of exclusion of porcine lumbar arteries. Methods: 6 endovascular grafts (3 self-expandable with integrated polyurethane wall versus 3 nitinol structures covered with polyester fabric) were implanted in 6 porcine aortae. Perfusion of lumbar arteries was assessed by angiography after Implantation and by angiography and dissection at graft explantation after 4 + 2 months. Tissue healing was evaluated by light and scanning electron microscopy. Results: Immediate exclusion of the lumbar arteries was achieved in 14/31 vessels (12 by polyurethane grafts and 2 by polyester grafts, p < 0.001). Follow-up angiography and dissection at explantation revealed perfusion of 30/31 lumbar arteries with a collateral network in most cases. Another reason for reperfusion of initially excluded branches was distention of the polyurethane grafts with resulting shortening allowing reperfusion of 8 of the 31 originally covered branches. Histological examination revealed a complete neointimal lining and a tight contact between endovascular grafts and aorta. Condusions: The immediate angiographic demonstration of exclusion of lumbar arteries predicts sealing characteristics of endovascular grafts. Later angiographic reappearance is due to development of a collateral network and possible shortening of self-expandable devices.

Lumbar artery - Aortic aneurysm - Endoprosthesis - Stent - Angiography