Intramural hematoma of the descending aorta-natural history and treatment

Aortic Intramural hematoma (IMH) represents a subtype of aortic dissection characterized by crescentic thickening of the aortic wall and the absence of an intimal flap or visualized entry point. The diagnosis is typically established by imaging techniques such as CT or MRI and the prevalence varies widely per published series between 5 and 48 % of all acute aortic syndromes. Patients with IMH share the same risk profile as those with typical aortic dissection though tend to be of older age. The symptoms are also similar to acute aortic dissection, including acute chest and back pain. Mortality for IMH in a large meta-analysis was 14 %, regardless of management. The majority of patients are treated with an initial medical approach, which is successful in the vast majority of patients. Certain patient groups may be at increased risk for progression to typical aortic dissection or rupture. Risks for progression of IMH include greater size of the aorta (i.e., 5 cm), presence of penetrating ulcers, Marfan syndrome, absence of beta-blockade, pleural effusions and persistent pain. Open surgical repair is utilized infrequently in type B IMH and reserved for complicated cases. In the current era, endovascular stent grafting would be the treatment of choice for symptomatic patients. Care should be taken to cover all potential areas of intimal communication by the stent graft.