Iliac artery involvement determines optimal therapy in acute uncomplicated type B aortic dissection.

Objective: The optimal treatment for acute uncomplicated type B aortic dissection (AUTBAD) remains unknown. The aim of this study was to characterize the efficacy of optimal medical therapy (OMT) in the treatment of AUTBAD and identify anatomic risk factors for OMT failure. Methods: A retrospective review of an aortic database from 2 aortic centers identified 293 patients with AUTBAD treated initially with OMT from 1995 to 2025. Inclusion criteria consisted of patients with initial imaging and death status available for analysis. An aortic event was defined as the need for an aortic intervention or an aortic-related death. Results: In total, 153 (52.2%) patients required an aortic intervention or experienced an aortic-related death during the study period. Aortic event-free survival at 1, 5, and 10 years was 62.9%, 43.8%, and 37.6%. For the 140 (47.8%) patients successfully maintained on OMT alone, aortic-related survival was 89.4%, 82.2%, and 76.9% at 1, 5, and 10 years. Patients with type B aortic dissection extending into the iliac arteries had a superior aortic event-free survival at 1 (iliac 70.8% vs no iliac 55.5%), 5 (iliac 49.5% vs no iliac 37.2%), and 10 years (iliac 44.6% vs no iliac 28.8%, Conclusions: Patients with AUTBAD and dissections ending proximal to the aortoiliac bifurcation benefit from TEVAR compared with OMT. Conversely, patients with dissections extending into the iliac arteries should be treated with OMT alone.