Abstract 17985: Natural History of Uncomplicated Stanford Type B Aortic Dissection and Intramural Hematoma

Background: Survivors of uncomplicated Stanford type-B aortic lesions treated with optimal medical therapy (OMT) are at high risk for aneurysm degeneration and late complications. The rate of false-lumen growth has practical and potentially prognostic implications. The purpose of this study was to evaluate the temporal evolution of aortic degeneration in patients with initially uncomplicated type-B aortic dissection (AD) and intramural hematoma (IMH). Methods: A retrospective cohort of 136 patients with uncomplicated type-B AD (n=92) and IMH (n=44) treated with OMT was assembled from the databases of two aortic centers in the US and EU. Aortic diameters and growth-rates were determined using a dedicated 3D software and protocol by comparing follow-up scans to CT scans obtained at baseline (within 14 days). Adverse events (AE) - defined as rapid growth, aneurysm formation (≥6cm), organ ischemia, and fatal or non-fatal aortic rupture, were recorded. Results: Rapid aortic growth with a diameter increase of ≥ 5 mm during the first 6 months of follow-up was associated with an increased risk of AE for AD (p Conclusions: More than one third of patients with initially uncomplicated type B AD or IMH experience an AE within five years. Early rapid aortic growth is associated with increased risk for AE in type-B AD.