Management strategies in acute type B aortic intramural hematoma.

PURPOSE OF REVIEW: Intramural hematoma (IMH) is one of the acute aortic syndromes. IMH was originally noted as an 'aortic dissection without intimal tear.' It had been speculated that IMHs were caused by ruptured vasa vasorum in the aortic media and distinguished from classical aortic dissections. However, the majority of IMHs are now detected with an intimal defect using high-resolution computed tomography, which implies that IMHs may be a subset of aortic dissections with very limited flow in the false lumen. Management of IMHs had been controversial, but guidelines published in the early 2010 s recommend treating IMHs as classical aortic dissections: surgical repairs were indicated for type A IMHs; complicated acute type B IMHs were treated with endovascular or open repairs and uncomplicated type B IMHs were to be managed with antiimpulse therapy and close surveillance. To date, based on the favorable long-term outcomes of preemptive thoracic endovascular aortic repair (TEVAR) for uncomplicated type B aortic dissections, early TEVAR for uncomplicated type B IMHs has been attempted. In this review, we describe the pathophysiology and management strategies for acute IMHs. RECENT FINDINGS: IMHs have intimal tears or disruptions in 70-80%. SUMMARY: Type B IMH should be managed with antiimpulse therapy, unless the patient has persistent pain or large ulcer-like projection.