Sequential Arch-Tear Eligibility for Uncovered Aortic Arch Stent in Acute DeBakey Type I Aortic Dissection

Because an uncovered arch scaffold does not provide a covered seal across an unresected arch tear, we evaluated a source-adjudicated sequential eligibility framework separating study-defined stop gates from residual-risk modifiers. Methods: We retrospectively analyzed 266 patients with acute DeBakey type I dissection treated by hemiarch repair alone (No. = 160) or hemiarch plus AMDS (No. = 106). Blinded preoperative CT-scan re-review validated Gate 1 (visible arch tear), and operative-report review confirmed Gate 2 (tear directly observed at open inspection). Supra-aortic false-lumen communication was assessed only after both gates were negative. Results: Sixty-nine patients (25.9%) passed both study-defined gates (AMDS = 32; hemiarch = 37). Twelve-month CT-scan was available in 45/69 (65.2%; AMDS 24/32, hemiarch 21/37). Among imaged patients, complete zone 2–3 false-lumen exclusion occurred in 20/24 (83.3%) after AMDS and 0/21 after hemiarch (risk difference +83.3 percentage points, 95% CI +58.7 to +93.3; p < 0.001). DANE occurred in 4/32 (12.5%) and 16/37 (43.2%), respectively (p = 0.007). Under the adverse opposing missingness scenario, the exclusion risk difference narrowed to +19.3 percentage points (95% CI −4.2 to +39.9; p = 0.148). Conclusions: These findings are hypothesis-generating and apply to a selected post hoc subgroup; treatment comparisons are non-causal. Prospective external validation of the study-defined hierarchy remains required.