AAR/AAR+HAR vs AAR+TAR+FET for Type A Aortic Intramural Hematoma

This is a prospective, randomized, controlled, non-inferiority study comparing two surgical strategies for acute type A aortic intramural hematoma (TAIMH). Patients with acute TAIMH will be screened and enrolled based on CTA confirmation of a completely thrombosed false lumen in the ascending aorta and aortic arch. Participants will be randomly assigned in a 1:1 ratio to receive either AAR/AAR+HAR or AAR+TAR+FET, with 200 participants in each group. Postoperative CTA will be performed before discharge, and follow-up CTA will be performed at 6 to 12 months after surgery. The surgical procedure will be performed through a median sternotomy or upper partial sternotomy. Cardiopulmonary bypass will be established through right axillary/femoral arterial and bicaval venous cannulation, or femoral arteriovenous cannulation and superior vena cava cannulation. Left ventricular venting will be achieved via the right superior pulmonary vein. Antegrade HTK or cold blood cardioplegia will be administered under direct vision and repeated every 30 minutes. During circulatory arrest, bilateral selective antegrade cerebral perfusion will be provided via the right axillary artery and left common carotid artery. The primary endpoint is the rate of reintervention on the aortic arch or descending aorta from 6 to 12 months after surgery. Secondary endpoints include circulatory arrest time, aortic cross-clamp time, major adverse cardiovascular events, other perioperative complications, and total hospitalization cost. The trial is designed to test whether the less extensive AAR/AAR+HAR strategy is non-inferior to AAR+TAR+FET with respect to the primary endpoint, while potentially offering advantages in operative burden, perioperative safety, and hospitalization cost.