Aortic Intramural Hematoma - Causes, Symptoms, Complications, Diagnosis, and Treatment

Introduction:

Aorta is a large artery that delivers oxygen-rich blood from the heart's left chamber to the rest of the body. The cleave in the small blood vessels that supply to the aortic walls leads to intramural aortic hematoma. It is more common among men between 60 years and 80 years of age.

What Is an Aortic Intramural Hematoma?

Aortic intramural hematoma occurs due to the damage to the tiny blood vessels (vasa vasorum) along the aorta wall. The blood leaks from the vasa vasorum and gets accumulated within the walls. It is also considered a variant of aortic dissection (caused by a tear in the aorta's inner layer).

How Is Aortic Intramural Hematoma Classified?

According to Stanford classification 4, intramural aortic hematoma is classified as:

• Type A involves the aortic arch's upward portion (ascending aorta), with or without affecting the downward part (descending aorta).

• Type B is more common, and it involves the descending aorta.

What Causes an Aortic Intramural Hematoma?

The main factor that leads to intramural aortic hematoma is unknown. However, there are certain factors like:

• Leakage of blood from the middle layer (tunica media) of the aorta leads to the formation of blood-filled spaces, weakening the aortic wall without rupturing the external layers of the aorta.

• Hypertension (increased blood pressure) causes thickening of the walls of the arteries, thereby affecting the normal blood flow.

• Atherosclerosis accumulates fat (plaque) and other substances in the artery's walls. As a result, it causes narrowing of arteries.

• Penetrating aortic ulcer (PAU) is an uncommon condition predisposing to intramural aortic hematoma. It mainly affects the downward portion of the aorta (descending aorta). The plaque formed in the aorta gets ulcerated, and it is initially confined to the external layer. Later it penetrates the middle muscular layer and causes a hematoma. Therefore, it is referred to as a secondary aortic intramural hematoma.

What Are the Symptoms of Aortic Intramural Hematoma?

The symptoms vary from one patient to another. The most observed are:

• Chest pain can be severe, and it can radiate to the back.

• Abdominal pain.

• Loss of consciousness (syncope).

• Rapid pulse.

• Hoarseness (husky voice).

• Shortness of breath.

• Weakness.

• Anxiety and heavy sweating.

What Are the Complications of Aortic Intramural Hematoma?

The complications that occur due to intramural aortic hematoma are as follows:

• Aortic Dissection is characterized by tearing of the aortic wall's inner layers, leading to blood flow between the layers. It creates an illusion of the formation of another lumen within the aorta. Instead, it leads to the wall weakening caused by the buildup of blood within the aortic walls.

• Cardiac Tamponade is characterized by a collection of blood or fluids within the sac covering the heart, which usually occurs due to a rupture of the upward portion of the aorta. The symptoms include loss of consciousness, decreased blood pressure, and altered mental status.

• Pericardial Effusion occurs due to the accumulation of blood from the ruptured portion of the aorta within the heart.

How to Diagnose Aortic Intramural Hematoma?

The early and accurate diagnosis of intramural aortic hematoma is essential as it may lead to complications. The diagnostic method includes:

• Magnetic Resonance Imaging (MRI) is a confirmatory test as it shows accurate images of the aortic wall. It helps differentiate intramural aortic hematoma from atherosclerosis.

• Computed Tomography (CT) produces images of the heart and blood vessels. In patients with intramural aortic hematoma, the imaging shows the crescent-shaped areas along the aorta without rupturing layers in the aortic wall.

• Transesophageal Echocardiography (TEE) involves the insertion of a particular probe (catheter) through the food pipe to assess the heart valve's structure, detect any clots, etc. It shows the thickness of the aortic wall is greater than 7 mm, which is also a feature of atherosclerosis. Therefore, the results of the echocardiography method are not considered valid in diagnosing intramural aortic hematoma.

What Is The Differential Diagnosis Of Aortic Intramural Hematoma?

• Aortitis is an inflammatory condition of the aorta leading to the increased thickness of its wall, similar to intramural aortic hematoma.

• Atheroma is characterized by a buildup of fat deposits around the heart's arteries that causes narrowing and restriction of blood flow. The distinguishing feature is that the fat deposits occur in a localized area, whereas the intramural aortic hematoma affects the greater area of the aorta.

• Aortic Dissection has clinical features similar to an aortic hematoma, and the radiographic techniques are essential in differentiation.

How to Treat Aortic Intramural Hematoma?

Patient management is planned immediately when the imaging results are abnormal, with increased complications like rupture of the aorta, pain, and unstable blood pressure. Asymptomatic patients can be observed and followed by regular imaging.

• Medications: There are no specific drugs to treat an intramural aortic hematoma. Certain drugs like -

1. Beta-blockers (Propanol, Metoprolol) or calcium channel blockers (Diltiazem) are given intravenously for patients with high blood pressure.
2. Vasodilators such as Nitroprusside are given along with beta-blockers to control blood pressure.
3. Analgesics are suggested to relieve the patient from pain.

• Surgical Management is planned mainly in patients with type A-aortic intramural hematoma as there are fewer complications in patients with type B. It includes:

1. Thoracic endovascular aortic repair (TEVAR) is a minimally invasive surgical procedure that involves the placement of a metal tube (stent) covered with a transplanted tissue (graft) along the defective area of the aorta. This stent allows the proper flow of blood and restricts the accumulation of blood in a localized area of the aorta.
2. Open surgical repair is a traditional method of repairing the aorta by placing a graft. Contrary to endovascular aortic repair, a larger incision is made in this procedure.

Conclusion:

The prognosis after surgical treatment in patients with intramural aortic hematoma is good and is found to increase the life span. Therefore early evaluation with accurate diagnostic methods and appropriate management is essential to improve the quality of a patient's life.