OBJECTIVETo report the investigational device exemption study 1-year clinical outcomes of the high neck angulation (HNA) substudy of the GORE EXCLUDER Conformable AAA Endoprosthesis (EXCC) for treatment of infrarenal abdominal aortic aneurysms (AAAs).METHODSThis study is a prospective, multicenter clinical trial conducted in the United States and included core laboratory assessment of imaging and independent event adjudication. Anatomical criteria for enrollment in the HNA substudy included infrarenal aortic neck angulation >60° and ≤90° with aortic neck length ≥10 mm. Primary safety end points included estimated blood loss of >1000 mL, death, stroke, myocardial infarction, bowel ischemia, paraplegia, respiratory failure, renal failure, and thromboembolic events. Primary effectiveness end points included technical success, absence from type I and III endoleaks, migration (≥10 mm), sac enlargement (≥5 mm), sac rupture, and conversion to open repair.RESULTSBetween January 2018 and February 2022, 95 patients were enrolled in the HNA substudy across 35 sites. Of the 95 patients, 71 (74.7%) were male and the cohort average age was 74.4 years. The mean infrarenal proximal aortic neck angle was 71.6° and the mean AAA size was 62.9 mm. Overall technical success was achieved in 93 patients (97.9%). Freedom from a primary safety end point through 30 days was 96.7%; 3 (3.3%) patients had an estimated blood loss of >1000 mL. Freedom from the primary effectiveness at 12 months was achieved in 94.8%. Four patients (4.3%) had a type IA endoleak; intervention after the procedure was not required and no subsequent interventions or sac enlargement were noted in these patients. At 12 months, 29 patients (39.7%) experienced a type II endoleak and 1 (1.3%) patient experienced AAA sac expansion of ≥5 mm. Through 12 months, 1 patient (1.3%) had a conversion to open surgical repair. There were no aneurysm-related deaths, ruptures, or migration through 12 months.CONCLUSIONSThe investigational device exemption study demonstrates safety and effectiveness of the GORE EXCLUDER Conformable AAA Endoprosthesis device in AAA with highly angulated necks (>60° and ≤90°) are preserved at the 12-month follow-up.