ObjectivesThis study aimed to evaluate the outcomes and anatomical predictors of the complications of flared limb (FL) use for ectatic common iliac arteries accompanied by abdominal aortic aneurysm treated with endovascular aneurysm repair (EVAR).MethodsIn this single-center retrospective study, we reviewed data from 391 patients (638 limbs) treated between 2005 and 2020. The cohort was divided into two groups. The standard limbs (SLs, = 403) included stent graft (SG) of <20 mm in diameter and the FLs ( = 235) included stent graft of ≥20 mm in diameter. Complications within 30 days were investigated as the short-term outcome. Limb events during follow-up including type Ib endoleak (EL), type IIIa EL, and limb occlusion were compared between SLs and FLs using log-rank test.ResultsEarly results indicated that the FL group had a significantly higher incidence of intraoperative type Ib EL at 5.1% (12), than 1.7% (7) in the SLs ( = .016). For 19 patients in whom intraoperative type Ib EL was discovered, SG extension alone or internal iliac artery embolization was all performed before completing the procedure. Overall, we noted one case of type Ib EL and two cases of limb events in each group at 30 days. Over a median follow-up of 39 months, 31 (4.9%) events (17 type Ib EL, 2 type IIIa EL, and 12 limb events), 13 (5.5%) in FLs and 18 (4.5%) in SLs ( = .984), were observed. The FLs had significantly higher rates of aortic sac enlargement, with 46 (19.6%) cases for FLs and 36 (8.9%) for SLs ( < .001). The Kaplan-Meier analysis revealed significant differences at 5 years in SLs versus FLs for freedom from type Ib EL (96.6% vs 82.4%, respectively; < .001) and no difference in freedom from limb events (94.7% vs 84.5%, respectively; = .519). Furthermore, no difference was observed for overall survival and aneurysm-related mortality.ConclusionsAlthough an FL for EVAR is used to treat dilated iliac arteries, there is an increased risk of intraoperative and late type Ib EL and aortic sac enlargement. Long-term close follow-up is mandatory, especially in the patients who undergo EVAR using FLs.