Limited intimal tear

Limited intimal tears (LIT) of the aorta or limited aortic intimal tears are subtle localized tears of the aortic intima without tear extension and represent an uncommon form of aortic dissection that can manifest as acute aortic syndrome ^1-5.

Epidemiology

Limited intimal tears are uncommon and account for approximately 5% of acute aortic syndromes ^1,2.

Associations

Limited intimal tears can be associated with the following conditions ^1-3:

• connective tissue diseases (e.g. Marfan syndrome)

• vasculopathy (e.g. Behcet disease, IgG4 aortitis)

Diagnosis

The diagnosis of limited intimal tears can be conveniently established by CT angiography, due to a lower level of awareness for this entity and their smaller size they might be missed on imaging ^1-3.

High-quality acquisitions and 3D rendering techniques might aid in the diagnosis ³.

Clinical presentation

Limited intimal tears can manifest as acute aortic syndrome and patients might complain of chest pain, neck pain, back pain or abdominal pain or present rarely with dyspnea hemoptysis or without symptoms ^1-3. Some patients have hypotension or hypertension at the time of presentation ¹.

Complications

Complications include ^1-3:

• limb ischemia or mesenteric ischemia

• pericardial effusion/hemopericardium

• pleural effusion/hemothorax

• dissection propagation

Pathology

Pathological limited intimal tears are attributed to cystic media degeneration ¹ without tear extensions.

They represent a class 3 aortic dissection tear type ^2,5,6 and may have various appearances including linear or stellate as well as T-shaped and L-shaped variants ³.

Classification

Like other aortic syndromes or aortic dissection limited intimal tears should be classified according to their location and the involvement of the ascending aorta with the following classification systems ^1-3:

• Stanford classification

• Debakey classification

Radiographic features

Echocardiography

The intimal tear might be detected on echocardiography as localized outpouching of the aortic wall ⁴.

CT

CT angiography may show the following ¹:

• linear or stellate as well as T-shaped and L-shaped luminal contour abnormalities

• undermined tear edges or focal flaps

• aortic bulge (outpouching of the residual aortic wall)

• associated findings and complications

  • pleural effusion/hemothorax

  • pericardial effusion/hemopericardium

  • pulmonary artery intramural hematoma

  • mediastinal hematoma

  • esophageal abnormalities

Radiology report

The radiology report should contain the following ¹:

• description and location

• type of the lesion

• associated intramural hematoma

• associated extracardiac findings and complications

Treatment and prognosis

Management is similar to other acute aortic syndromes. Stanford type A lesions should be considered for urgent surgical repair ^1,2. In the absence of major complications, Stanford type B limited intimal tears can be managed medically ¹. Overall prognosis seems to be similar as in classic dissection, intramural hematomas and penetrating aortic ulcers.

History and etymology

Limited intimal tears of the aorta were first described by the American pathologists Charles A Murray and Jesse Efrem Edwards in 1973 as ‘incomplete dissecting aneurysms’ ⁷.

Differential diagnosis

Differential diagnoses of limited intimal tears on imaging include other types of aortic syndromes especially ³:

• penetrating aortic ulcer: associated arteriosclerosis changes

• intramural hematoma  

• ulcer-like projections

• classic aortic dissections