Clinical outcomes of conservative management for acute Stanford type A intramural hematoma: a multicenter retrospective study.

The optimal management strategy for acute Stanford type A intramural hematoma (ATAIMH) remains controversial. This study compared outcomes between conservative and surgical management and to evaluate the validity of current treatment strategies. We retrospectively analyzed 274 consecutive patients with ATAIMH and treated at six centers between April 2011 and April 2024. Conservative management was initially considered for patients with stable hemodynamics, controlled pain, AoD < 50 mm, and HT < 11 mm. Outcomes included all-cause mortality, aortic-related mortality, and major adverse cardiovascular or cerebrovascular events (MACCE). Survival outcomes were compared between patients managed conservatively and those who underwent surgery using Cox proportional hazards models, with surgical intervention as a time-dependent covariate. Of the 274 patients, 88 (32.1%) underwent emergency surgery, whereas 186 (67.9%) were initially managed conservatively; among these, 58 (31.1%) required subsequent surgical conversion. Surgical intervention was not an independent predictor of all-cause mortality (HR 0.986; 95% CI 0.487-1.99; P = 0.970), aortic-related mortality (HR 0.836; 95% CI 0.319-2.18; P = 0.715), and MACCE (HR 1.29; 95% CI 0.633-2.64; P = 0.478). Five-year survival rates were 83.9% in the conservatively treated group and 86.8% in the surgically treated group. The only independent predictor of aortic-related mortality was aortic diameter indexed to body surface area, with a cutoff value of 32.3 mm/m2. Initial conservative management with timely surgical conversion may be a feasible treatment strategy for selected patients with ATAIMH.