What is the diagnosis and treatment for an intramural aortic hematoma (Intramural Hematoma of the Aorta)?

From the Guidelines

Intramural aortic hematoma (IMH) is a serious condition that requires prompt diagnosis and treatment, with urgent surgery indicated in complicated cases and initial medical therapy under careful surveillance recommended in uncomplicated cases.

Diagnosis and Treatment

The diagnosis of IMH is based on imaging criteria, including crescentic or circular thickening of the aortic wall with maximal thickness greater than or equal to 7 mm on TEE without intimal flap or tear or longitudinal flow in the false lumen 1.

• Medical therapy, including pain relief and blood pressure control, is recommended in all patients with IMH 1.
• Urgent surgery is indicated in cases of Type A IMH, particularly in complicated cases with pericardial effusion, periaortic haematoma, or large aneurysms 1.
• Initial medical therapy under careful surveillance is recommended in cases of Type B IMH, with repetitive imaging (MRI or CT) indicated in uncomplicated cases 1.
• Thoracic endovascular aortic repair (TEVAR) should be considered in complicated Type B IMH, while surgery may be considered in certain cases 1.

Important Considerations

• The natural history of IMH is variable, with the hematoma potentially resolving, converting to a classic dissection, or leading to aortic enlargement and rupture 1.
• The clinical behavior of IMH varies according to the location, with IMH involving the ascending aorta having a high, early risk of complication and death with medical treatment alone 1.
• Patient comorbidities and anatomic constraints should be taken into account when deciding on the treatment approach 1.
• The absence of an intimal defect can present a diagnostic and treatment challenge, and the writing committee believes that treatment of IMH corresponding to treatment of aortic dissection in the corresponding segment of the aorta is reasonable 1.

Clinical Outcomes

• In-hospital mortality for Type A IMH is 26.6%, with higher mortality observed in cases involving the aortic valvular complex 1.
• In-hospital mortality for Type B IMH is 4.4%, but worsens once surgery is indicated 1.

From the Research

Diagnosis of Intramural Aortic Hematoma

• Intramural aortic hematoma (IMH) is diagnosed using imaging techniques such as transesophageal echocardiography (TEE), chest computed tomography (CT), magnetic resonance (MRI), and multy detector computed tomography (MDCT) 2, 3
• Diagnosis is typically made in patients presenting with chest and back acute penetrating pain 2
• Imaging characteristics such as location, mural thickness, and aortic diameter are important for prognostication and guiding clinical decision making 3

Treatment of Intramural Aortic Hematoma

• Treatment of IMH depends on the location and severity of the condition 2, 4, 3
• Surgery is indicated for patients with type-A IMH, as well as those with persistent and/or recurrent pain 2
• Medical treatment is suggested for patients with type-B IMH without incessant pain and/or without complications 2
• Endovascular surgery and stent-graft placement is currently indicated in type B IMH 2, 5
• Early surgical management is the treatment of choice for patients with Stanford type A IMH, while most patients with Stanford type B IMH have a good short-term outcome with aggressive control of hypertension 3
• In some cases, IMH may undergo gradual regression despite anticoagulation therapy 6