statdx/docs_md/articles/limited-intimal-tear_bb253de9-ab48-4740-89bd-0036fb8c12f5.md

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Limited Intimal Tear	bb253de9-ab48-4740-89bd-0036fb8c12f5	key value 5de0df07-7b3e-4678-8767-1519e1153f29 Dominik Fleischmann, MD key value 5a4d7c03-82a7-4740-947a-9638213aec4a Mohammad H. Madani, MD	name slug treeNodeId Cardiac cardiac fa90100b-619c-430e-8074-b5b9789bab39 name slug treeNodeId Diagnosis diagnosis 5c92cf4f-e9d5-4059-9c13-22255c51c121 name slug treeNodeId Aorta aorta 4d206a6b-1a82-467c-9199-0df25ab749d7 name slug treeNodeId Limited Intimal Tear limited-intimal-tear null	Cardiac	99a74e38-6a58-4b21-94d4-8e0da4c2bf13	17	02/10/25	Limited Intimal Tear	Cardiac, Diagnosis, Aorta, Limited Intimal Tear	Limited Intimal Tear | STATdx	Limited Intimal Tear	DX	true	Cardiac Diagnosis Aorta Limited Intimal Tear

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title: "Limited Intimal Tear" docid: "bb253de9-ab48-4740-89bd-0036fb8c12f5" authors:

• key: "5de0df07-7b3e-4678-8767-1519e1153f29" value: "Dominik Fleischmann, MD"
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• name: "Cardiac" slug: "cardiac" treeNodeId: "fa90100b-619c-430e-8074-b5b9789bab39"
• name: "Diagnosis" slug: "diagnosis" treeNodeId: "5c92cf4f-e9d5-4059-9c13-22255c51c121"
• name: "Aorta" slug: "aorta" treeNodeId: "4d206a6b-1a82-467c-9199-0df25ab749d7"
• name: "Limited Intimal Tear" slug: "limited-intimal-tear" treeNodeId: null category: "Cardiac" documentVersionId: "99a74e38-6a58-4b21-94d4-8e0da4c2bf13" imageCount: 17 lastUpdated: "02/10/25" pageDescription: "Limited Intimal Tear" pageKeywords: "Cardiac, Diagnosis, Aorta, Limited Intimal Tear" pageTitle: "Limited Intimal Tear | STATdx" enhancedTitle: "Limited Intimal Tear" type: "DX" references: true breadcrumbs:
• "Cardiac"
• "Diagnosis"
• "Aorta"
• "Limited Intimal Tear"

---

KEY FACTS

• Terminology

  • Limited tear, incomplete dissection, partial thickness tear, limited dissection
  • Limited tears of aorta are rare cause of acute aortic syndromes (AASs), representing ~ 5% of AASs

• Imaging

  • In general, limited intimal tears (LITs) appear as intimal irregularity or defect, often associated with undermined edge (reminiscent of localized dissection), which may contain small amount of thrombus, and bulging of corresponding outer wall of aorta
  • Actual tearcan be subtle and difficult to delineate, as it can be linear or have more complex shapes
  • Edges of tear can be subtle, unexpected contour irregularity of inner surface of aorta; edges can be lifted or rolled off remainder of wall, reminiscent of dissection; undermined edges can contain intramural thrombus

• Clinical Issues

  • Natural history of acute LITs is poorly understood
  • LITs are treated similar to aortic dissections
  • Stanford type A LITs (affecting ascending aorta) typically undergo open surgical replacement of aorta
  • In Stanford type B LITs (not involving ascending aorta), medical management is appropriate unless complications occur; anatomically suitable type B LITs can undergo endovascular aortic repair
  • All patients with LITs require life-long follow-up and imaging surveillance

• Diagnostic Checklist

  • Key to diagnosing LITs is being aware of existence of these relatively rare lesions
  • Contour irregularities of inner surface of aorta, which cannot be explained by motion artifacts or other cause, should raise suspicion of LIT

TERMINOLOGY

• Abbreviations

  • Limited intimal tear (LIT)

• Synonyms

  • Limited tear, incomplete dissection, partial thickness tear, limited dissection

• Definitions

  • Limited tears of aorta are rare cause of acute aortic syndromes (AASs), representing ~ 5% of AASs
  • Limited tears fall under spectrum of diseases characterized pathologically by degeneration of media layer of aortic wall

IMAGING

• General Features

  • Best diagnostic clue

    - Intimal irregularity or defect, often associated with undermined edge, which may contain small amount of thrombus; bulging of delaminated and exposed outer wall of aorta
    

  • Location

    - LITs occur more commonly in ascending aorta than in arch or descending aorta
    - LITs are oriented longitudinally, or are circumferentially relative to aortic axis
    

  • Size

    - Tear itself can range from few millimeters to several centimeters in length; width can range from few mm to few centimeters
    

  • Morphology

    - Actual tear can be subtle and difficult to delineate
            - Can be linear or have more complex shapes (figure 8 shape)
    - Edges of tear can be subtle
            - Can appear as unexpected contour irregularity of inner surface of aorta
            - Edges can also be undermined with portion of intimomedial tissue lifted off remainder of wall, reminiscent of dissection, but without fully formed false lumen
    - Outer wall of aorta at level of LIT may show subtle focal bulging
            - Outer wall of aorta only consists of residual adventitia, equivalent to outer wall of false lumen in aortic dissection
    

• CT Findings

  • Aortic luminal contour abnormality in shape of linear or complex-shaped tear - Edge of tear is better visualized if it is lifted off, giving appearance of focal dissection flap, or accompanied by small amount of intramural thrombus - Exposed and delaminated remainder of (outer) aortic wall bulges outward
  • Associated findings may be similar to those seen in aortic dissection - Pericardial fluid or hemopericardium (in type A lesions) - Pulmonary artery subadventitial hematoma - Periaortic mediastinal stranding (in type B lesions)

• Ultrasonographic Findings

  • LITs have been described on transesophageal and transthoracic echocardiography

• Imaging Recommendations

  • Best imaging tool

    - CTA, ideally with ECG gating
    

  • Protocol advice

    - CT scans without motion artifacts in ascending aorta can be achieved with fast scanning techniques (fast gantry rotation, high-pitch, wide detector), and, most reliably, by ECG gating
            - If ECG gating is not routinely performed, or if suspicious aortic lesion is detected (e.g., on pulmonary embolism CT study), repeat injection and ECG gated scan can be performed
    - Multiplanar reformations are essential and increase confidence for presence or absence of subtle LIT
    - 3D volume-rendered images with "transparent blood" display are most helpful to see shape and extent of lesion
    

DIFFERENTIAL DIAGNOSIS

• Artifacts

  • Motion artifacts from transmitted cardiac pulsation (double contours of aortic wall on CT) can simulate or obscure subtle LITs
  • Motion artifacts are often visible on both opposing aortic walls, whereas true aortic lesions usually affect only 1 side
  • Repeat scan with ECG gating usually allows accurate diagnosis

• Intramural Hematoma

  • There is overlap between spectrum of LITs and spectrum of intramural hematomas (IMHs) - LITs can be associated with localized intramural blood, notably at undermined edges of tear, but predominant finding is intimal tear and defect
  • It would not be fundamentally wrong to consider some LITs as IMH with large entry tears - Main task for radiologist is to recognize lesion as acute aortic pathology - Treatment is dictated by location and presence of complications rather than by specific type or classification of lesion

• Penetrating Atherosclerotic Ulcer

  • LITs are sometimes mislabeled as PAUs, most notably if LIT is small and has small hematoma associated with it
  • Pathology of PAUs is very different though, since PAUs are atherosclerotic lesions, whereas LITs are under spectrum of diseases characterized by media degeneration

PATHOLOGY

• General Features

  • LITs fall under spectrum of aortic diseases characterized pathologically be degeneration of aortic media - Formerly, but incorrectly, termed cystic media necrosis
  • Other diseases characterized by media degeneration are classic aortic dissection and IMH (dissection variant) - Of note, media degeneration can precede acute event for years; loss of coherence between layers of aortic wall can go unnoticed for long time until entry tear allows physical separation and delamination of wall layers
  • Media degeneration is prerequisite for aortic dissection and its variants, IMH, and LIT; conversely, normal aorta does not dissect
  • Causes of media degeneration are - Severe, untreated hypertension - Most common cause of media degeneration - Aging: Normal aging results in media degeneration - Genetic diseases: Marfan syndrome, Ehlers-Danlos IV syndrome, familial aortic aneurysms and dissections

• Staging, Grading, & Classification

  • Limited tears are anatomically categorized similar to aortic dissections - Stanford type A for ascending aortic lesions - Stanford type B for all other lesions that do not affect ascending aorta
  • Similar to classic dissection, LITs are considered hyperacute (24 hours), acute (< 14 days), subacute, or chronic (> 3 months)

• Gross Pathologic & Surgical Features

  • Intimal-medial tear; limited or focal medial layer dissection plane, medial degeneration

CLINICAL ISSUES

• Presentation

  • Most common signs/symptoms

    - Clinical presentation of acute LITs is similar to other acute diseases of aorta, summarized under clinical term acute AASs
            - AAS symptoms: Acute, sharp, severe chest or back pain
            - AAS can be caused by number of aortic diseases other than LITs, such as classic dissection, IMH, PAU, and also rupturing aneurysms
    

  • Other signs/symptoms

    - LITs may cause little or no symptoms, evidenced by occasional incidental detection of chronic LITs in patients who do not remember specific event
    

• Demographics

  • Patients with LITs are on average slightly older than patients with classic aortic dissection and patients with IMH

• Natural History & Prognosis

  • Natural history of acute LITs is poorly understood
  • Acute phase: Similar to aortic dissection, first 14 days are considered acute phase of disease
  • Subacute phase (15-90 days): LITs seem to evolve with any IMH component receding and disclosing depth of undermined edges; tear may become more visible if edges become thicker and less mobile, and exposed adventitial bulge may become deeper (similar to false lumen increase during subacute phase in dissection)
  • Chronic phase: Delaminated portion of aortic wall that is exposed to systemic pressure will continue to dilate and can become aneurysmal; since less wall is exposed in LITs than in classic dissection, changes over time may be less - Chronic LITs are occasionally detected in asymptomatic patients, suggesting that they may present with less conspicuous symptoms in some cases
  • All patients with LITs require life-long follow-up and imaging surveillance

• Treatment

  • LITs are treated similar to aortic dissections - Stanford type A LITs (affecting ascending aorta) typically undergo open surgical replacement of aorta - In Stanford type B LITs (not involving ascending aorta), medical management is appropriate unless complications occur, such as rupture and malperfusion - Anatomically suitable type B LITs requiring intervention will undergo thoracic endovascular aortic repair

DIAGNOSTIC CHECKLIST

• Consider

  • Key to diagnosing LITs is being aware of existence of these relatively rare lesions

• Image Interpretation Pearls

  • Contour irregularities of inner surface of aorta, which cannot be explained by motion artifacts or other causes, should raise suspicion of LIT
  • If associated with undermined edge or with subtle intramural blood, this should prompt further visualization with multiplanar reformats, and, ideally, with volume-rendered 3D images, which can more clearly demonstrate characteristics of this lesion

• Reporting Tips

  • LITs are aortic emergency and need to be reported and communicated urgently, similar to acute aortic dissection
  • Distinction between type A lesions (ascending aorta involved) vs. type B lesions is critical, since former usually undergo urgent surgical repair
  • Presence of complications, such as pericardial fluid, hemopericardium, tamponade; signs of rupture, branch vessel compromise

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References

Selected References

1. Madani MH et al: Limited aortic intimal tears: CT imaging features and clinical characteristics. Radiol Cardiothorac Imaging. 4(6):e220155, 2022
2. Chin AS et al: Acute limited intimal tears of the thoracic aorta. J Am Coll Cardiol. 71(24):2773-85, 2018
3. Svensson LG et al: Intimal tear without hematoma: an important variant of aortic dissection that can elude current imaging techniques. Circulation. 99(10):1331-6, 1999
4. Murray CA et al: Spontaneous laceration of ascending aorta. Circulation. 47(4):848-58, 1973

Images

Selected Images

CT images (top) show a linear filling defect and contour irregularity in the ascending and transverse aorta. Note undermined edges of the tear and the bulging wall . 3D images (bottom) show a longitudinally oriented limited tear seen from the outside (left) and inside (right). (Courtesy Chin et al.)

CT images (top) show a linear filling defect and contour irregularity in the ascending and transverse aorta. Note undermined edges of the tear and the bulging wall . 3D images (bottom) show a longitudinally oriented limited tear seen from the outside (left) and inside (right). (Courtesy Chin et al.)

Axial ECG gated images of a limited intimal tear (LIT) show contour irregularities in the ascending aorta, which correspond to the undermined edges of a large LIT. (Courtesy Chin et al.)

Schematic shows the luminal view of intimomedial tear shapes (column 1), their stretched open luminal appearance in a pressurized aorta (column 2), external bulges (column 3), and side view (column 4). Schematic also illustrates linear (A), L-shaped (B), T-shaped (C), and star/complex shaped (D) tears. (Courtesy Madani et al.)

Inner/luminal view of a semicircumferential LIT in the ascending aorta is shown. Note that the tear is stretched open in vivo (left). The edge of the tear is viewed from above (right).

External view of the semicircumferential LIT shows a band or stripe of bulging tissue in the ascending aorta with sharp, undermined edges .

Corresponding intraoperative photograph shows a very thin aortic wall only consisting of residual adventitia. The normal aortic wall is thicker with a more yellow hue due to the underlying intact media, which contains elastin.

Photograph of the LIT in a resected aortic wall is shown. Note that in vitro, the shape of the tear is mostly linear with a small "L" on the right end. In vivo, in a pressurized aorta, that tear appears stretched open, and exposed underlying adventitial will bulge out (as shown on CT images).

CECT shows contour abnormality with a filling defect representing a limited aortic intimal tear . An associated periaortic and mediastinal hematoma is consistent with impending rupture.

The proximal end of the LIT shows the undermined edge, reminiscent of a dissection, seen on the left aspect of the ascending thoracic aorta . (Courtesy S. Kligerman, MD.)

Chronic LITs show slightly thicker , undermined edges, no periaortic stranding, and no associated intramural blood.

Corresponding oblique sagittal CECT in the same patient shows a focal tissue flap consistent with an undermined edge of a LIT . (Courtesy S. Kligerman, MD.)

The classic appearance of a LIT in the aortic arch with a wide, stretched open tear with undermined edges and bulging of the outer aortic wall is shown.

Corresponding oblique coronal view shows a LIT with a small, undermined edge/flap and a mild bulge of the outer aortic contour . (Courtesy S. Kligerman, MD.)

Very subtle contour irregularity in the proximal descending thoracic aorta is seen, which was initially missed on day 1 of hospitalization when only axial images were reviewed.

Follow-up imaging (day 6) again shows only very subtle bulging of the descending thoracic aorta with contour irregularities at the edge . Only the side-by-side comparison raises the suspicion of an aortic abnormality.

3D volume-rendered view of the proximal descending aorta clearly shows the LIT is apparent even on day 1.

3D volume-rendered image on day 6 clearly shows the LIT and that it has grown and expanded over just a few days.