---
title: Intramural haematoma of the aorta
description: What intramural haematoma of the aorta and penetrating atherosclerotic ulcer are, how they differ from dissection, how they are detected, which treatment approaches clinical guidelines describe and when to call an ambulance.
type: disease
aliases:
  - IMH
  - intramural haematoma
  - intramural hematoma
  - penetrating atherosclerotic ulcer
  - PAU
sources:
  - tier: guideline
    org: esc
    title: 2024 ESC Guidelines for the management of peripheral arterial and aortic diseases
    year: 2024
    doi: 10.1093/eurheartj/ehae179
    url: https://doi.org/10.1093/eurheartj/ehae179
  - tier: guideline
    org: aha-acc
    title: '2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease: A Report of the American Heart Association/American College of Cardiology Joint Committee on Clinical Practice Guidelines'
    year: 2022
    doi: 10.1161/CIR.0000000000001106
    url: https://doi.org/10.1161/CIR.0000000000001106
  - tier: guideline
    org: minzdrav-rf
    title: Расслоение аорты
    year: 2025
    url: https://cr.minzdrav.gov.ru/view-cr/946_1
sources_checked: 2026-10-14
review: null
---

Intramural haematoma (IMH) of the aorta is a collection of blood within the middle layer of the wall of the <Structure id="aorta">aorta</Structure>, with no overt tear of the inner layer and no false lumen.<Cite n={[2, 3]} /> Together with [aortic dissection](../aortic-dissection/) and penetrating atherosclerotic ulcer (PAU), it belongs to the acute aortic syndromes, life-threatening conditions in which the integrity of the aortic wall is breached and which can lead to aortic rupture.<Cite n={[2, 3]} /> This article covers both conditions, IMH and PAU.

<Diagram name="intramural-hematoma">
  <p slot="normal">The aortic wall has three layers: a thin inner layer (intima), a thicker middle layer (media) and a thin outer layer (adventitia). Blood flows through a single round lumen.<Cite n={2} /></p>
  <p slot="disease">In intramural haematoma, blood enters the media and clots, thickening the wall in a crescent shape; there is no blood flow in this thickening. There is no visible intimal tear, no detached flap and no second lumen, and the aortic lumen looks almost normal.<Cite n={[2, 3]} /></p>
</Diagram>

## Why it happens

<Patient>

In IMH, blood gets into the aortic wall in one of two ways: either small vessels that supply the wall itself burst, or there are tiny tears in the inner layer that cannot be seen on standard scans.<Cite n={[2, 3]} /> People with IMH are usually older than people with dissection, and more often have high blood pressure and atherosclerosis.<Cite n={2} />

A PAU starts as an ulcer in an atherosclerotic plaque on the inner wall of the aorta: the ulcer breaks through the inner layer, blood enters the middle layer, and an intramural haematoma often forms around it.<Cite n={[2, 3]} /> People with a PAU usually have extensive atherosclerosis of the aorta and the heart arteries, and often high blood pressure and a history of smoking; men are affected more often.<Cite n={2} />

An IMH may be reabsorbed, but it may also progress to dissection, widening or rupture of the aorta.<Cite n={[2, 3]} /> An ulcer may stay stable, but it may also grow and progress to a haematoma, dissection, false aneurysm (pseudoaneurysm) or rupture.<Cite n={[2, 3]} />

</Patient>

<Student>

The ACC/AHA and the Russian Ministry of Health guideline define IMH as blood within the media in the absence of an overt intimal tear or patent false lumen; the blood comes from rupture of the vasa vasorum or from small intimal tears that are not visualised on standard imaging.<Cite n={[2, 3]} />

The classification is the same as for dissection: type A involves the ascending aorta, and type B does not.<Cite n={[2, 3]} /> According to the ACC/AHA, IMH occurs more commonly in the descending thoracic aorta (60%) than in the ascending aorta (30%) or the arch (10%).<Cite n={2} /> The ACC/AHA and the Russian Ministry of Health guideline report that 5–25% of patients with suspected acute aortic syndrome have IMH; according to the ACC/AHA, this proportion approaches 30–40% in Asian studies.<Cite n={[2, 3]} />

The ACC/AHA and the Russian Ministry of Health guideline estimate that PAU accounts for 2–7% of all cases of acute aortic syndrome.<Cite n={[2, 3]} /> It most often appears in the middle or distal descending thoracic aorta, less often in the arch and abdominal aorta, and rarely in the ascending aorta; multiple ulcers are often present.<Cite n={[2, 3]} /> An ulcer-like projection in IMH is not the same as a PAU: it is not associated with an atherosclerotic plaque.<Cite n={[2, 3]} />

</Student>

<HeartModel highlight={['aorta']} />

## Symptoms

<Patient>

The symptoms of IMH are similar to those of aortic dissection.<Cite n={2} /> Usually this is sudden, severe pain in the chest or back, sometimes in the abdomen, which is worst at the very start.<Cite n={2} /> Reduced blood supply to organs can occur, but less often than in dissection.<Cite n={2} />

A PAU is increasingly found by chance, on a CT scan done for another reason, when there are no symptoms at all.<Cite n={2} />

</Patient>

<Student>

IMH is considered complicated in the presence of malperfusion, periaortic haematoma, pericardial effusion with cardiac tamponade, persistent, refractory or recurrent pain, or rupture.<Cite n={[2, 3]} />

The ESC lists the following high-risk features of type A and type B IMH: involvement of the ascending aorta, difficult blood pressure control, persistent or recurrent pain, progression to dissection, focal intimal disruption with an ulcer-like projection, increasing haematoma thickness and aortic diameter, pericardial effusion at admission (type A), recurrent pleural effusion and organ malperfusion.<Cite n={1} /> The threshold values for aortic diameter and haematoma thickness differ between the ESC, ACC/AHA and Russian Ministry of Health guidelines.<Cite n={[1, 2, 3]} />

</Student>

## How it is diagnosed

<Patient>

The diagnosis is made on imaging: a CT scan of the aorta with contrast dye (CT angiography), MRI or echocardiography.<Cite n={[2, 3]} /> These show a crescent-shaped or ring-shaped thickening of the aortic wall with no blood flowing through it.<Cite n={[2, 3]} /> When acute aortic syndrome is suspected, the main test is CT angiography.<Cite n={[1, 2]} /> An ultrasound of the heart through the chest wall is also done, but IMH is often not visible on it, so it is not enough on its own.<Cite n={[1, 3]} />

</Patient>

<Student>

Non-contrast images are decisive for the diagnosis of IMH: on them the haematoma appears as a high-attenuation crescentic or circumferential thickening of the wall, and contrast images show no blood flow in a false lumen.<Cite n={[2, 3]} /> Unlike in aortic dissection, the aortic lumen is rarely narrowed in IMH, and no intimal fragments are seen after contrast.<Cite n={3} /> According to the Russian Ministry of Health guideline, the sensitivity of transthoracic echocardiography for detecting IMH is below 40%.<Cite n={3} />

</Student>

## How it is treated

<Patient>

Treatment starts straight away, usually in an intensive care unit: pain is relieved and blood pressure is lowered to reduce the strain on the aortic wall.<Cite n={[1, 2, 3]} />

In type A IMH, when the ascending aorta is involved, urgent surgery is usually needed.<Cite n={[1, 2, 3]} /> Only in selected people with a high surgical risk, no complications and no warning signs on imaging may doctors choose a watch-and-wait approach under monitoring.<Cite n={[1, 2, 3]} />

In uncomplicated type B IMH, treatment starts with medicines under close monitoring, with repeat CT or MRI scans.<Cite n={[1, 2, 3]} /> If complications develop, an urgent procedure is needed.<Cite n={[2, 3]} /> In type B this is usually endovascular repair: a special graft (stent graft) is placed inside the aorta.<Cite n={1} />

The approach to PAU is similar: everyone receives pain relief and blood pressure lowering; an ulcer in the ascending aorta is operated on, one in the descending aorta is first treated with medicines under monitoring, and a stent graft is placed if complications occur.<Cite n={1} /> If the ulcer ruptures, an urgent procedure is needed.<Cite n={2} />

After the acute phase, the aorta continues to be checked with imaging: new problems with the aorta, such as an aneurysm, can develop after IMH too.<Cite n={[1, 2]} /> Which treatment is needed is decided by a doctor.

</Patient>

<Student>

The evidence base is limited: all ESC recommendations on IMH and PAU are level of evidence C, and the ACC/AHA note that prospective randomised comparative studies are lacking and most series and registries are limited by small sample sizes.<Cite n={[1, 2]} />

According to the ACC/AHA, IMH, especially type A, is complicated by rupture at presentation in 18% of cases, and with a nonoperative strategy mortality in type A reaches 40% according to data from the International Registry of Acute Aortic Dissection (IRAD).<Cite n={2} /> According to the Russian Ministry of Health guideline, in-hospital mortality in type A IMH is similar to that in type A aortic dissection.<Cite n={3} /> The experience of successful medical management of type A comes mostly from Japan, Korea and China; according to the ACC/AHA, these results may not be generalisable to other populations, and the Russian Ministry of Health guideline notes high mortality with medical management in Europe and the US.<Cite n={[2, 3]} />

In complicated type A or type B IMH, urgent repair is recommended; in complicated type B the ESC recommends TEVAR (thoracic endovascular aortic repair), and in uncomplicated type B with high-risk imaging features TEVAR should be considered.<Cite n={[1, 2, 3]} />

According to the ACC/AHA and the Russian Ministry of Health guideline, the risk of rupture in PAU reaches 40%.<Cite n={[2, 3]} /> Incidental asymptomatic PAUs without high-risk features have a low risk of progression; for small, isolated, asymptomatic ulcers the ESC allows conservative management with regular surveillance.<Cite n={[1, 2]} /> For more on aortic widening, see the articles on [thoracic aortic aneurysm](../thoracic-aortic-aneurysm/) and [abdominal aortic aneurysm](../abdominal-aortic-aneurysm/).

</Student>

## When to call an ambulance

Acute aortic syndrome is life-threatening: if it is not recognised and treated quickly, mortality can reach 1–2% per hour.<Cite n={2} /> Call your local emergency number (112 in the EU, 911 in the US and Canada, 999 in the UK) for sudden, severe pain in the chest or back (sometimes in the abdomen), especially if it is worst at the very start.<Cite n={2} /> The pain is not necessarily "tearing": more often it is described as sharp or stabbing.<Cite n={2} /> It is especially alarming if such pain comes with a sudden focal neurological deficit (for example, weakness in an arm or a leg) or with signs of shock.<Cite n={2} /> As with any heart condition, call an ambulance for fainting, chest pain or severe shortness of breath: this is the site's general safety rule, repeated at the bottom of every page.

<Quiz />