Arterial Aneurysms Flashcards
What is an aneurysm?
A localised permanent abnormal dilatation of a blood vessel by greater than 1.5x its normal diameter.
What is an aortic aneurysm?
An aorta with a diameter of more than 3cm (normally it is less than 2cm).
What is the distribution of aortic aneurysms?
95% in abdominal aorta; 5% in thoracic aorta.
Give 4 risk factors for the development of aneurysms.
- Smoking (Major).
- Hypertension (Major).
- Syphilis.
- Connective Tissue Disorders e.g. Ehlers-Danlos Type I, Marfan’s Syndrome.
Give 5 main causes of arterial aneurysms.
- Atheroma.
- Trauma.
- Infection e.g. Mycotic - Infective Endocarditis, Thoracic - Syphilis.
- Connective Tissue Disorders.
- Inflammation e.g. Takayasu’s Aortitis.
What is a true aneurysm?
An aneurysm where all 3 layers of the arterial wall are involved.
What is a false aneurysm?
Only a single layer of fibrous tissue forms the aneurysm wall - it is an expanding pulsatile haematoma in continuity with a vessel lumen that is not lined by endothelium.
Give 4 common sites of aneurysm formation.
- Aorta (Infrarenally commonly).
- Iliac Artery.
- Femoral Artery.
- Popliteal Artery.
Give 2 shapes of aneurysms.
- Saccular - spherical shape, bulging out the side of the vessel e.g. Berry.
- Fusiform - spindle shape, involving the whole circumference of the vessel e.g. AAAs.
Give 4 complications of aneurysms.
- Rupture (due to weakening of the vessel wall).
- Thrombosis (due to turbulent blood flow).
- Compression of External Structure to cause Radiculopathy or Claudication.
- Fistula Formation.
Presentation of Rupture of Aneurysm (2).
- Commoner in aorta, iliac artery, femoral artery.
2. Presents with hypovolaemic shock.
Presentation of Thrombosis of Aneurysm (2).
- Commoner in popliteal artery.
2. Presents with ischaemia distal to the site of occlusion.
