Long-term Outcomes of Flared Limbs in Aneurysmal Iliac Arteries

Abdominal aortic aneurysms often occur concomitantly with aneurysmal iliac arteries requiring treatment by flared endograft limb, branch device, or hypogastric embolization with external iliac extension during endovascular repair. The long-term natural history of a flared limb in an aneurysmal iliac artery remains unclear. The purpose of this study was to determine the adequacy of flared limb use in aneurysmal iliac arteries. A retrospective review of a prospectively collected database for one large vascular group was queried for large iliac limb use. A large limb was defined as a limb larger than 18 mm in diameter. Demographics, operative details, and ancillary procedures were tabulated and compared using standard statistics. There were 346 limbs with an iliac device limb >18 mm in diameter (LRG) and 1646 limbs with devices <18 mm (REG) implanted between January 1, 2013 and January 1, 2018 and observed for a median of 5.9 months (range, 1-52 months). Demographics were similar between LRG and REG, respectively: age, 72.0 years (range, 48-94 years) vs 72.7 years (range, 33-100 years); male sex, 89.8% vs 71.2%; coronary disease, 19% vs 20%; hypertension, 46% vs 46%; cholesterol, 41% vs 37%; chronic obstructive pulmonary disease, 9.4 vs 13.4; renal, 2% vs 3%; diabetes, 8.9% vs 10.3%; and tobacco, 20% vs 18%. Operative mortality was similar between LRG and REG (1.63% vs 1.46%; P = .849). The devices for the LRG group were 205 Gore, 9 Cook, 11 Medtronic, 18 Endologix, and 3 Ovation. The devices for the REG group were 567 Gore, 203 Medtronic, 21 Endologix, and 14 Cook. Postoperatively, 2 patients in the LRG group had acute limb occlusion vs 13 acute events in the REG group. Long-term outcomes regarding revisions such as extensions and coiling were not significant (24 [9.8%] LRG vs 107 [13%] REG; P = .173). Aneurysmal iliac arteries are frequently associated with abdominal aortic aneurysms, and the natural history of an aneurysmal iliac artery treated with a large stent graft has been ill defined. This large series demonstrates the safety and long-term durability of flared limb use in large iliac arteries.