An aneurysm is the pathological bulging of an artery. Most often it occurs in the abdomen (abdominal aortic aneurysm). If an aneurysm ruptures, life-threatening internal bleeding can occur

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Aneurysm - in short

An aneurysm is a locally limited bulge in the area of ​​the arterial blood vessels. Aneurysms can be found, for example, in the main artery (aorta), the brain arteries or in the area of ​​the leg arteries. The cause of the development of an aneurysm is a weakness in the wall of the artery (media layer), usually caused by calcification of the vessels (arteriosclerosis). In many cases, an aneurysm does not initially cause any symptoms. If an aneurysm ruptures, this can manifest itself in severe pain in the affected vascular area and is a life-threatening condition. The diagnosis is made through an ultrasound examination or computed tomography. How and whether an aneurysm needs to be treated depends on the size, diameter and location of the aneurysm, among other things. In addition to open surgical procedures, endovascular procedures are also available.

Representation of the course of the main artery (aorta)

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What is an aneurysm?

An aneurysm is a localized enlargement of a carotid artery. A bulge forms in the relevant vessel section, which remains permanently. In principle, an aneurysm can form on any artery. Most often it occurs in the lower area of ​​the main artery (abdominal aorta), below the renal arteries. More rarely, aneurysms occur in the upper main artery (the thoracic aorta) and on the cerebral vessels. Aneurysms can also be found in the arm and leg arteries. A bulging of the heart wall (heart wall aneurysm) can form after a heart attack.

As an aneurysm grows in size, there is a risk that it will rupture. With such a rupture, the person affected can bleed to death internally, depending on the location of the pouch. Men are more often affected by aneurysms than women, older people more often than younger people. An aortic aneurysm is the second most common disease of the main artery (aorta) after arteriosclerosis.

Background information - the structure of the vessel wall

In order to better understand the various forms of aneurysm, the structure of the vessel wall must first be explained.

The arterial wall consists of three layers. The outer layer, the tunica externa (also called adventitia), serves to strengthen the blood vessel and fix it in its environment. The tunica media (also just called media) follows inwards. It is characterized by smooth muscle cells and elastic fibers. This middle layer regulates the diameter of the vessel and thus the flow resistance that the blood flowing through it has to overcome. The third, inner wall layer is called tunica intima (short: intima). Towards the interior of the vessel (vessel lumen), it is lined (covered) with a single-cell, smooth layer, the endothelium. Its cells convey important information to the media, for example whether the vessel should expand or narrow. The endothelium plays a key role in the development of arteriosclerotic damage to the vascular wall.

Causes: what causes an aneurysm?

When the arterial wall is weakened by disease or injury, an aneurysm can form. Such wall damage occurs very often as a result of arteriosclerosis, also known colloquially as "hardening of the arteries". Vascular calcification in arterial vessels, such as the coronary arteries (CHD, coronary artery disease) or the leg arteries (PAD, peripheral arterial occlusive disease) also indicates calcifications in other arteries. Thus, already known diseases due to arteriosclerosis (such as CHD) are also considered a risk factor for an aneurysm.

With the abdominal aortic aneurysm there are other risk factors such as older age, male gender, smoking, high blood pressure and a positive family history.The more often an abdominal aortic aneurysm occurs in close relatives, the more likely it is that you can be affected yourself.

Congenital malformations of the blood vessels, connective tissue disorders (Marfan syndrome or Ehlers-Danlos syndrome), injuries to the vascular wall or, more rarely, bacterial infections such as syphilis or tuberculosis can promote an aneurysm. Smaller aneurysms on the coronary arteries are found in Kawasaki syndrome. The main cause of an aneurysm of the heart wall is a previous heart attack.

What types of aneurysm are there?

A distinction is made between "real aneurysms" and forms, which are also called aneurysms, although strictly speaking it is not a real vasodilatation (see also our picture gallery).

Aneurysm verum: In a real aneurysm (aneurysm verum), all three wall layers of the artery protrude outwards.

Aneurysm falsum or spurium: A "false" aneurysm is caused, for example, by an injury to the artery. Some blood will leak out and get next to the vessel. First a bruise (hematoma) forms and then a type of blood clot, which after a while is covered by a connective tissue capsule.

Aneurysm dissecans (split aneurysm): As the name suggests, the wall layers in the area of ​​the tunica media are split open (dissection). In this way, in addition to the normal vascular tube ("true lumen"), a second cavity is formed between the vascular layers ("false lumen").

If the intima ruptures at one point, blood enters this new cavity and digs further down through the layers of the vessels. The blood flow in the "wrong" lumen can compress outgoing vessels so much that only little blood flows in them and this can lead to circulatory disorders (such as kidney failure, stroke, peripheral circulatory disorders). If the inner wall layer tears a second time at a point further below (distal), the blood in the vessel wall receives a "re-entry gate" back into the vessel interior (see also picture gallery).

Furthermore, aneurysms can also be differentiated into saccular (sac-like) or fusiform (spindle-like) shapes according to their shape. Often there is a mixed form.

Forms of an aneurysm

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Aneurysm verum (real aneurysm)

In the case of a real aneurysm, there is an expansion of the vessel, which is still surrounded by all three wall layers (intima, media and adventitia).

Shown here is a fusiform (fusiform) shape.

© Shutterstock

Aneurysm verum (real aneurysm)

In the case of a real aneurysm, there is an expansion of the vessel, which is still surrounded by all three wall layers (intima, media and adventitia).

Pictured here is a sack-like (saccular) shape.

© Shutterstock

Aneurysm spurium (or falsum) - "false" aneurysm

A leak in the arterial wall causes blood to leak out of the vessel. A pool of blood (extravascular hematoma) forms there, which is increasingly organized and forms a capsule around the pool of blood. The limitation of the blood is not the vessel wall, but a connective tissue capsule, hence the term "false" aneurysm.

It can arise, for example, after a vessel has been punctured or after vascular surgery.

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Aneurysm dissecans

In the case of aneurysm dissecans, a tear in the intima leads to bleeding between the vascular layers. Blood accumulates between the intima and adventitia layers, i.e. within the media layer. The rooting hemorrhage leads to a split in the wall layer and can span a stretch of length of different lengths. There is a double lumen of the artery. A re-entry of the blood through a renewed tear of the intima (re-entry) located below the tear (entry) is also possible.


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Severe chest pain can be caused by rupturing an aneurysm

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Symptoms: what symptoms does an aneurysm cause?

An aneurysm usually does not cause any symptoms. They are often discovered by chance during a routine examination, such as an ultrasound scan of the abdomen or an X-ray of the lungs. However, as soon as they are discovered, regular check-ups should take place in order to detect any increase in the size of the aneurysm in good time. Because with increasing size, the risk increases that an aneurysm can tear and thus lead to life-threatening bleeding. The indication for the operation is determined according to the size (diameter) and the increase in size per year (see also therapy).

Symptoms that can indicate an aneurysm only occur when the enlargement has progressed so much that the vascular branches are affected. Depending on the location of the aneurysm, the following symptoms can be found:

In the case of an aneurysm in the chest, these are, for example, difficulty swallowing, coughing, hoarseness, breathing difficulties or circulatory disorders in the arms. Certain EKG changes and symptoms of cardiac insufficiency and cardiac arrhythmias may indicate a cardiac wall aneurysm.

An aneurysm in the abdomen can cause pain in the abdomen or back. With a large aneurysm, very slim people may feel a pulsation in the abdomen.

Bleeding from a cerebral artery aneurysm causes sudden severe headache, facial pain, or nausea. In addition, the person affected can become unconscious.

Blood clots (thrombi) form almost regularly in aneurysms of the abdominal aorta and the arm and leg arteries. These or parts of them can become detached, migrate with the bloodstream into other vascular sections and lead to vascular occlusions there.

Alarm signal: Sudden pain - an absolute emergency

If an aneurysm ruptures or the vessel wall splits open (dissection), pain is usually sudden, usually very severe, and persistent. Where these arise depends on the location of the aneurysm. Characteristically, with an abdominal aortic aneurysm, there is often flank pain that radiates into the back or legs, and / or pain in the lower abdomen occurs. If the aneurysm tears freely into the abdomen, there is a great risk of internal bleeding. A ruptured chest artery aneurysm can cause severe chest pain that is similar to symptoms of a heart attack. "Tearing pain" can also sometimes be described by those affected, this is often found in the area between the shoulder blades.

If the vascular wall on the aorta near the heart splits, bleeding into the pericardium (pericardial tamponade) can occur. This triggers an acute, life-threatening heart failure / shock situation.

If you suspect an aneurysm tear (rupture), the emergency services must be notified immediately! Because of the possible pronounced internal bleeding, an aneurysm rupture is an acutely life-threatening condition.

Diagnosis: How is an aneurysm diagnosed?

Often aneurysms can be detected with the help of an ultrasound examination. However, not all sections of the large body arteries and small arteries can be recorded with it, which is why computed tomography with a contrast medium (CT angiography) or catheter angiography are used for precise diagnosis. A ventricular aneurysm is diagnosed using a special ultrasound method - echocardiography - or angiography. Contrast medium is injected into the (left) heart chamber through a catheter and the aneurysm is displayed on a screen and digitally stored. For certain questions, a so-called transoesophageal echocardiography (TEE) - an ultrasound examination from the esophagus - is used, as it allows certain sections of the main artery to be better assessed. A magnetic resonance examination (MRT) is not used in acute diagnosis, but is particularly useful for control examinations in young patients with already known aortic aneurysms.

The rarely occurring aneurysms of the leg and arm arteries can sometimes be felt. In these cases, the doctor feels a thickening thickening of the arm or leg. In the case of aneurysms of the abdominal or pelvic arteries, this is only possible if the expansion of the vessels is already very large and the patient is slim. In overweight patients, palpation of an abdominal aortic aneurysm is very difficult, so that if certain risk factors exist, preventive examinations (ultrasound, CT) can be useful.

Flow noises that occur in the rhythm of the heartbeat and that can be detected by listening to the arteries are also typical.

Therapy: How is an aneurysm treated?

If an aneurysm ruptures, internal bleeding usually occurs, which can have life-threatening consequences. Therefore, this emergency must be treated immediately - usually by means of a surgical procedure.

For smaller aneurysms that do not cause discomfort, the aim of treatment is to ensure that the vasodilatation does not enlarge or tear. Risk factors such as high blood pressure and lipid metabolism disorders should be treated if possible (drug therapy). Anyone who smokes should definitely try to give up their vice.

Aneurysm: when do you need to operate?

The larger an aneurysm becomes, the more pressure there is on the affected vessel wall. If it can no longer withstand this, it can tear and cause life-threatening bleeding. This is why doctors recommend surgery to remove aneurysm larger than a certain size.

For an abdominal aortic aneurysm four to five centimeters in diameter, the risk of rupturing is about one percent per year. From a size of five centimeters, the risk increases to more than ten to 20 percent per year. Therefore, experts recommend preventive surgery from a diameter of 5 to 5.5 centimeters. Women are at greater risk of tearing, so they should be treated when they are 4.5 to 5 centimeters tall. An increase in size of over 10 millimeters per year can also lead to an operation recommendation.

A critical value for an aneurysm in the chest area (thoracic aortic aneurysm) is a diameter of 5.5 centimeters as a recommendation for an operation for those affected (without Marfan's syndrome or valve anomaly). If the aneurysm affects the ascending section of the aorta (ascending aorta) or the aortic arch, surgical treatment is usually required. In the case of an aneurysm in the descending section of the aorta (descending aorta), endoluminal prostheses are increasingly used if drug therapy is insufficient (TEVAR, see below). However, the time of operation must always be determined individually, for example based on personal risk factors.

In principle, there are two different surgical procedures for treating aortic aneurysms: open surgical treatment and the so-called endovascular (endoluminal) aortic replacement.

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In this "open" operation, the enlarged part of the vessel is cut open or removed and replaced with a tubular or Y-shaped plastic prosthesis. The vessel wall is then closed again (as far as possible) as a natural covering over the prosthesis.

  • Endovascular aortic replacement (Endovascular Aortic Repair, EVAR, TEVAR)

In some cases, an endovascular stent prosthesis can be used as an alternative to surgery. It consists of a metal grid that is encased by a vascular prosthesis. When folded, the prosthesis is inserted into the inguinal artery with a catheter and advanced to the aneurysm of the abdominal (EVAR) or thoracic aorta (thoracic endovascular aortic repair, TEVAR). The stent and its sheath then unfold in the aneurysm, separating it from the bloodstream. In order to be able to use this therapy method, however, various requirements must be met (see below).

For aneurysms of the cerebral arteries, surgery on the brain used to be common. The aneurysm was clamped out with a clip. Doctors are now also using an endovascular technique: using a very thin catheter, they insert platinum micro-coils (coils) into the aneurysm in the brain via the inguinal artery. These micro-coils cannot completely fill the vessel, but they do cause a blood clot to form and in this way turn off the aneurysm. The timing of the operation depends, among other things, on the affected area, the general condition and age of the patient and the risk of a tear and must be determined individually.

Larger aneurysms of the ventricle usually do not rupture, but are often the cause of increasing cardiac insufficiency and cardiac arrhythmias. Surgery to reduce the size of the heart chamber may be appropriate to prevent heart failure from getting worse. The aneurysm is cut out. However, the risk of such an operation is not small.

Weigh up the individual advantages and risks

The choice of treatment method for all aneurysms depends on their shape and extent as well as the general condition of the patient. The endovascular method is not suitable for every patient. In the case of aneurysms in the chest in particular, the risk of complications (e.g. bleeding, stroke) must be weighed against the expected success of the operation when performing a surgical procedure at a very old age. Which procedure is suitable in each individual case and which complications can arise should therefore be discussed in detail with the treating physician.

Our advisory expert:

Professor Dr. med. Wolfram Delius is a specialist in internal medicine and cardiology. He completed his habilitation at the Medical University Clinic Uppsala, Sweden, and then held an extraordinary professorship for medicine at the Technical University of Munich. The heart specialist worked for a long time as chief physician, most recently for two decades in the cardiology / pulmonology department at the Munich-Bogenhausen Municipal Hospital (academic teaching hospital). He now runs his own practice in Munich.
Professor Delius has been actively involved in advanced training events of the Bavarian Medical Association for years and was awarded the Ernst von Bergmann plaque of the German Medical Association.


  • German Society for Cardiology, ESC Pocket Guidelines, "Aortic Diseases". Online: Krankungen1.pdf (accessed on April 5, 2019)
  • R. Erbel et al., Cardiologist 2015 · 9: 348–353, "Commentary on the 2014 guideline of the European Society of Cardiology (ESC) on the diagnosis and treatment of aortic diseases". Online: https: // diseases.pdf (accessed on April 5, 2019)

Important NOTE:
This article contains general information only and should not be used for self-diagnosis or self-treatment. He can not substitute a visit at the doctor. Unfortunately, our experts cannot answer individual questions.

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