Last updated: September 1, 2023

Summarytoggle arrow icon

True aneurysms are an abnormal dilation of an artery due to a weakened vessel wall. By contrast, false aneurysms are external hematomas with a persistent communication to a leaking artery. Dissections are a separation of the arterial wall layers caused by blood entering the intima-media space after a tear in the internal layer occurred. Aneurysms are differentiated according to their location. This card discusses the etiology and clinical features of cerebral, external carotid, Iliofemoral, popliteal, and ventricular aneurysms. Symptoms generally depend on the location and size of the aneurysm. There are surgical and endovascular treatment options, the choice of which depends on the specific type of aneurysm and if symptoms or complications are present.

For more specific information on individual types of aneurysms, see the articles on thoracic aortic aneurysm, abdominal aortic aneurysm, aortic dissection, dissection of the carotid and the vertebral artery, and subarachnoid hemorrhage.

Overviewtoggle arrow icon

Overview of features of aneurysms and arterial dissection [1]
True aneurysm False aneurysm (pseudoaneurysm) Arterial dissection
  • Abnormal dilation of an artery due to a weakened vessel wall
  • Leaking artery leads to a hematoma between the vessel and the surrounding tissue
  • Persistent communication between vessel and hematoma remains
  • Separation of the arterial wall layers
Etiology/Risk factors
  • Usually trauma (e.g., deceleration injury, gunshot) or iatrogenic (e.g., after vascular puncture or cardiovascular surgery)
  • Inflammation and proteolytic degeneration of connective tissue proteins leads to: [2]
    • Loss of structural integrity of the aortic wall
    • Widening of the vessel
  • Perforation of the vascular wall causing bleeding into the surrounding tissue leads to:
    • Formation of an extravascular (pulsatile) hematoma
    • Surrounding structures delimit the expansion of the hematoma
    • Organization of the hematoma
    • Formation of a false vascular wall and false aneurysm
  • Typical deceleration injury → contained aortic injury of the thoracic aorta (typical location: distal to the left subclavian artery)
  • Transverse tear in the arterial intima leads to:
    • Blood entering the intima-media space (creating a false lumen)
    • Hematoma formation that propagates longitudinally downwards
    • Rising pressure within the aortic wall and rupture, occlusion of branching vessels, and ischemia in the affected areas
Clinical features
  • See table below.
  • Painful and pulsatile mass at the site of trauma
  • Buzzing sensation
  • Bruit on auscultation
  • Uncomplicated pseudoaneurysm [3][4]
    • < 3 cm and asymptomatic: observation and periodic monitoring with duplex sonography
    • ≥ 3 cm and/or symptomatic: ultrasound-guided thrombin injection
      • Ultrasound is used to guide the needle, through which thrombin is injected directly into the cavity of the pseudoaneurysm.
      • Thrombin initiates rapid formation of blood clots, which stops the bleeding.
  • Complicated pseudoaneurysm : open surgical repair

Types of aneurysms according to location
Type Location Etiology Clinical features
Thoracic aortic aneurysm (TAA)
Abdominal aortic aneurysm (AAA)
Coronary artery aneurysm
Cerebral aneurysm
  • Depends on type of aneurysm (berry, fusiform, mycotic, traumatic, or microaneurysms)
Ventricular aneurysm
Popliteal aneurysm
Iliofemoral aneurysm
Carotid aneurysm

Cerebral aneurysmtoggle arrow icon


Clinical features



External carotid artery aneurysmtoggle arrow icon

Ventricular aneurysmtoggle arrow icon

Popliteal aneurysmtoggle arrow icon


Iliofemoral aneurysmtoggle arrow icon


Referencestoggle arrow icon

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  2. Zhang Z, Guo J. Predictive risk factors of early onset left ventricular aneurysm formation in patients with acute ST-elevation myocardial infarction.. Heart Lung. ; 49 (1): p.80-85.doi: 10.1016/j.hrtlng.2019.09.005 . | Open in Read by QxMD
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  23. Charcot-Bouchard aneurysms. Updated: February 7, 2017. Accessed: February 7, 2017.
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