Endovascular Repair of Type IV Thoracoabdominal Aneurysms

Abstract

Background Type IV thoracoabdominal aortic aneurysms are characterized byinvolvement of the visceral aortic segment which determines the lack of a proximal aortic neck suitable for the implantation conventional stents. Fenestrated stents have been specially developed for these cases. We describe the experience of a surgical center using fenestratedstents in six patients. All the stents were successfully implanted, respecting 20 visceral vessels. This approach is a valid alternative for patients who are at high risk for conventional surgery. BACKGROUND The lack of a proximal aortic neck suitable for endograft attachment is currently the main anatomical reasonto exclude patients fromendovascular repair of abdominal aortic aneurysms using conventional stentgrafts. Several studies have demonstrated that the presence of proximal neck dilatation, neck angulation, short neck length, neck thrombus or a funnel-shaped aortic neck are related with insufficient attachment in terms of quality and time and associated with a greater incidence of proximal endoleak , stentgraft migration and even aneurysm rupture. (1-3) Conversion to conventional open aortic repair of type IV thoracoabdominal aneurysms are associated with a high rate of complications, including mortality. (4-6) Fenestrated stent-grafts (with orifices in the Dacron graft that allow the connection with the visceral arteries) have been developed to improve proximal implantation of the device, incorporating the visceral segment of the aorta to the usual zone of deployment, sealing and shear strength. This technique has proved to be feasible, safe and effective at the mid-term. (7) The experience of a surgical team with endovascular repair of complex aortic aneurysms is described. METHODS