Intramural aortic haematoma following intra-aortic balloon counterpulsation. Documentation by transoesophageal echocardiography

Optimal timing of type A intramural hematoma repair

Acute type A aortic intramural hematomas (IMHs) are often included under the spectrum of acute aortic syndromes. The classical definition is the presence of hematoma in the media without identifiable intimal tear. Dissection occurring within two weeks of presentation is defined as acute. Acute type A IMH remains a subject of debate, especially regarding its definition and management. The classical theory of pathogenesis of IMHs is ruptured vasa vasorum in the aortic media. However, the majority of IMHs are now detected with an intimal defect using high-resolution computed tomography and intravascular ultrasound, which implies that IMHs may be a subset of aortic dissections (ADs), with very limited flow in the false lumen. Much controversy remains regarding IMH differences in presentation, diagnosis, and risk for progression. Geographic location and ethnicity, especially Asian vs. Western, possibly affect the natural history and outcomes of acute type A IMH. In this review, we describe the pathophysiology and management strategies for acute type A IMHs.

Aortic intramural hemorrhage: A distinct disease entity with mystery

Aortic intramural hemorrhage (IMH) is one of the disease processes that comprise the spectrum of acute aortic syndrome (AAS) with clinical manifestations and a mortality rate similar to those of classic aortic dissection (AD). However, IMH should be considered as a distinct disease entity rather than a precursor to classic dissection because of differences in their pathology, etiology, natural history, and imaging findings. Multidetector computed tomography (CT) is recommended as the first-line diagnostic imaging modality for IMH, but transesophageal echocardiography (TEE) and magnetic resonance imaging (MRI) are also helpful. There is still debate over the appropriate treatment of IMH. Medical treatment of type B IMH appears effective and safe, while surgical treatment is recommended for type A IMH. Thoracic endovascular aortic repair (TEVAR) is a promising treatment for selected patients, and more clinical evidence needs to be assembled.

Update in acute aortic syndrome: intramural hematoma and incomplete dissection as new disease entities

Acute aortic syndrome is a relatively recent clinical entity. Non-invasive imaging methods, such as computed tomography and transesophageal echocardiography, have contributed significantly to the diagnosis of variant forms of classic aortic dissection, which have become important disease entities in acute aortic syndrome. Imaging findings may result in risk stratification and application of different treatment options, providing a rational approach to achieve a better outcome of this syndrome. This review will focus on the imaging characteristics of two important variant forms of classic aortic dissection, intramural hematoma and incomplete dissection, and the role of imaging methods in the evaluation of differences in the hemodynamic status of false lumens that contributes to patient prognosis.

Imaging features of intramural hematoma of the aorta

Intramural hematoma (IMH) is defined as localized hemorrhage within the aortic wall and is included in the acute aortic syndrome spectrum with aortic dissection and penetrating aortic ulcer. The mortality from IMH is similar to classic aortic dissection (21%). 16% of patients with IMH will evolve to classic aortic dissection over time. Despite this confusion exists regarding the precise definitions and radiologic features of IMH versus penetrating ulcers with mural thrombus and overt aortic dissection.

Meta-analysis of 143 reported cases of aortic intramural hematoma

Aortic intramural hematoma (IMH) is a clinical condition that has still not been completely defined. We conducted a meta-analysis of reported cases and analyzed the demographic profiles, imaging modalities, pathologic sites, and treatment strategies in relation to outcome in 143 patients with IMH. We performed an English language search of Medline for manuscripts with the keywords "aortic diseases," "aorta AND hematoma," and "intramural hematoma." Data from 143 reported cases were extracted. IMH of the aorta has a reported incidence of 5% to 20% among patients with acute aortic syndromes and a mortality rate of 21%. Most patients were men (61%) and median age was 68 years (range 15 to 88). Hypertension was a predisposing factor in 53% of the patients. Most patients had chest and/or back pain (80%). Transesophageal echocardiography, computer tomographic scan, or magnetic resonance imaging may be effectively used to diagnose this condition. There is no difference in the overall mortality rates in Stanford type A versus type B patients. Patients with Stanford type A IMH who underwent surgery, compared with those who underwent medical management, had a significantly better prognosis (14% vs 36% mortality, respectively, p < 0.02). Patients in Stanford group A who received medical treatment had a higher mortality rate than those in group B who received medical treatment (36% vs 14% mortality respectively, p < 0.02). In type B patients, medical and surgical outcomes were similar.

Aortic intramural hematoma during coronary angioplasty: insights into the pathogenesis of intramedial hemorrhage

We report a case of a 74-year-old woman who had an aortic intramural hematoma as a complication of percutaneous coronary angioplasty. Transesophageal echocardiography enabled the diagnosis of aortic intramural hematoma and was very useful in the patient's management and follow-up.

Natural history and serial morphology of aortic intramural hematoma: a novel variant of aortic dissection

BACKGROUND

Acute aortic dissection is a cardiovascular emergency that requires prompt diagnosis and treatment. Transesophageal echocardiography is the current standard diagnostic imaging modality in many medical centers. Aortic intramural hematoma is a variant of aortic dissection whose natural history and prognosis have not been well studied. We performed transesophageal echocardiography in patients with aortic intramural hematoma to determine the echocardiographic characteristics and echocardiographic evolution of this lesion, impact on patient management, and patient outcome.

METHODS AND RESULTS

Twenty-one consecutive patients with aortic intramural hematoma confirmed anatomically (four patients) or with an additional diagnostic imaging technique (17 patients) underwent a transesophageal echocardiographic examination. Fifteen patients with longstanding hypertension had chest or back pain, and the intramural hematoma was visualized in the ascending aorta (n = 4), along the whole aorta (n = 4), in the descending aorta (n = 6), or in the aortic arch (n = 1). The thickening of the aortic wall was crescentic. Patients with ascending aortic intramural hematoma had the following results: two patients died suddenly, three patients underwent surgery because of increased aortic wall thickening (one patient) or secondary intimal tear (two patients), and the remaining three patients had regression of the hematoma. Patients with hematoma confined to the descending aorta and the patient with aortic arch involvement (n = 7) had a different result: one patient died from aortic rupture and the remaining six patients did well. Six patients had a traumatic aortic injury, and the intramural hematoma was located along the descending thoracic aorta. The thickening of the aortic wall was circular in five patients and crescentic in one. Three of these patients had normalized thickness of the aortic wall on follow-up transesophageal echocardiographic studies. The other three patients died from multiorgan system failure. Aortography showed a reduction of the diameter of the aortic lumen in four patients; diameter in the remaining 17 patients was normal.

CONCLUSIONS

Aortic intramural hematoma can be detected and monitored by transesophageal echocardiography but not by aortography. Two types of aortic intramural hematoma can be distinguished: (1) traumatic of good prognosis and (2) nontraumatic, which can be an early stage of the classic aortic dissection, with bad prognosis in cases involving the ascending aorta.