Objective or BackgroundTo report the investigational device exemption (IDE) 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 (AAA). MethodsThis study is a prospective, multicenter clinical trial conducted in the United States and included core laboratory assessment of imaging and independent event adjudication. Anatomic criteria for enrollment in the HNA substudy included infrarenal aortic neck angulation >60° and ≤90° with aortic neck length ≥10 mm. Primary safety endpoints included blood loss >1000 mL, death, stroke, myocardial infarction, bowel ischemia, paraplegia, respiratory failure, renal failure, and thromboembolic events. Primary effectiveness endpoints included technical success, absence from Type I and III endoleak, 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 old. The mean infrarenal proximal aortic neck angle was 71.6° and mean AAA size was 62.9 mm. Overall technical success was achieved in 93 (97.9%) patients. Freedom from a primary safety endpoint through 30 days was 96.7%; 3 (3.3%) patients had blood loss >1000 mL. Freedom from the primary effectiveness at 12 months was achieved in 94.8%. Four (4.3%) patients had 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 (39.7%) patients experienced a Type II endoleak and 1 (1.3%) patient experienced AAA sac expansion ≥5mm. Through 12 months, 1 (1.3%) patient had a conversion to open surgical repair. There were no aneurysm-related deaths, ruptures, or migration through 12 months. ConclusionsThe IDE study demonstrates safety and effectiveness of the EXCC device in AAA with highly angulated necks (>60° and ≤90°) are preserved at the 12-month follow-up.