Aortic Arch Atresia vs Interrupted Aortic Arch in Adults: A Systematic Review and Reclassification Analysis

Introduction Aortic arch atresia and interrupted aortic arch are rare lesions traditionally distinguished by the presence or absence of anatomic continuity between the aortic arch and descending aorta. However, adult cases reported as interrupted aortic arch frequently demonstrate substantial morphologic ambiguity, and the distinction from aortic arch atresia or advanced coarctation-related obliteration remains inconsistently described in the literature. Methods PubMed and Scopus were systematically searched from database inception to April 2025 for reports of adult patients (≥18 years) with aortic arch atresia or interrupted aortic arch. Case reports, case series, and cohort studies with sufficient clinical, imaging, or surgical detail were included. Data were extracted on fibrous continuity, collateral circulation, associated anomalies, clinical history, treatment strategies, and outcomes. An aortic arch atresia-likeness score (range, 0-4) was applied for standardized reclassification. Results A total of 111 reports involving 121 patients were identified. Based on the score, 34 patients were classified as aortic arch atresia-likely, 17 as interrupted aortic arch-likely, and 70 as intermediate because published information was insufficient for definitive adjudication. Patients classified as interrupted aortic arch-likely were younger than those classified as aortic arch atresia-likely. Short-term outcomes were generally favorable across classifications. Conclusions Many adult cases reported as interrupted aortic arch lacked sufficient morphologic information for definitive distinction from aortic arch atresia or advanced coarctation-related obliteration. Standardized assessment of arch continuity and collateral anatomy, including use of the aortic arch atresia-likeness score as an exploratory descriptive framework, may improve diagnostic consistency and educational interpretation of these uncommon lesions.