A prospective analysis of fenestrated endovascular grafting: intermediate-term outcomes

Abstract

Conclusion: Abdominal aortic stent grafts can be placed with graft material incorporated around visceral arteries with effective prevention of aneurysm rupture and minimal loss of visceral artery patency. Summary: The study included patients with abdominal aortic aneurysm (AAA) with short proximal necks who were considered high risk for open repair and unacceptable for conventional endovascular repair. Fenestrated devices were individually designed from reconstructed computed tomography (CT) data using the Cook Zenith graft as the device platform. The design of each graft required knowledge of the ostial diameter of each visceral vessel, relative distances from a fixed landmark (usually the superior mesenteric artery), and radial orientation of the visceral ostial. Small fenestrations were placed between stent struts and could be used in conjunction with a visceral artery stent. Larger fenestrations (8 to 12 mm in diameter) could be placed with a stent strut crossing an ostium and were not intended for use with visceral artery stents. Scalped fenestrations, hemi-oval in shape, were in the most proximal portion of the fabric. Patients were followed-up with CT scan, duplex ultrasound imaging, and plain abdominal radiographs at hospital discharge, at 1, 6 and 12 months, and then annually thereafter. Between 2001 and 2005, 119 patients were treated. Their mean age was 75 years, and the mean aneurysm size was 65 mm. There were 302 visceral vessels inferior to the fabric seal, with a mean of 2.5 vessels per patient. Fifty-eight percent of the grafts incorporated two venal arteries and the superior mesenteric artery. There was no acute visceral artery loss at the time of the graft implantation. Mean follow-up was 19 months (range, 0 to 42 months). One death occurred ≤30 days of device implantation. Survival by Kaplan-Meier analysis at 1, 12, 24, and 36 months was 99%, 92%, 83%, and 79%, respectively. There were no conversions, and no known aneurysm ruptures have occurred. There were 11 type 1 endoleaks at discharge. The endoleak rate was 10% at 30 days, and all were type 2. At 2 years, fenestrations had decreased >5 mm in diameter in 77% of cases. During follow-up, 10 of 231 renal artery stents occluded, with three occlusions before discharge. There were 12 additional renal artery stent stenoses. Three patients had permanent dialysis. Comment: Outside of a few selected centers, progress has been slow in the development of fenestrated endovascular grafts. This is likely because the grafts must be individually designed and a high level of technical skill is required for successful placement. Acceptance of this technology will also require conclusive evidence that the graft body itself does not migrate. As pointed out by the authors, even minimum migration of a fenestrated graft will result in significant renal and mesenteric artery complications.