Aneurysm Flashcards
What is an aneurysm?
A focal dilation of an artery that is 50% more than its normal diameter
What are causes of aneurysm formation?
- Atherosclerotic: e.g. aortic, popliteal
- Developmental: e.g. berry aneurysm
- Infective: mycotic in endocarditis, syphilitic in tertiary syphilis
- Developmental: Marfans/Ehlors-Danlos syndrome
- Trauma
How can aneurysms present?
- Mass effects: pressuring adjacent structures
- Embolic events: due to development of mural thrombi
- Haemorrhage: due to rupture
What are the common sites for aneurysm formation?
Major arteries:
- Abdominal
- Aorta
- Iliac Artery
- Femoral Artery
- Popliteal Artery
Describe the surveillance of AAAs?
What defines an abdo aortic aneurysm?
USS screening is offered to males at age 65
Abdo aortic aneurysms are 5x more common in males, and are mainly asympotic
Dilations of the abdominal aorta to >3cm
How does an AAA rupture present?
- Severe continuous/intermittent epigastric pain, radiating to the back
- Pulsatile, expansile abdominal mass
- Signs of shock
How do you management AAA rupture?
Survival rates?
- Emergency A-E resuscitation
- Theatre - Clamp the aorta the leak, then insert a graft
Only 50% of ruptured AAAs make it to hospital, of these pts, 50% will not survive the operation
How do you manage an unruptured AAA?
Depends on size or rate of expansion
- AAA <5.5cm
- Monitor with regular USS/CT
- Reduce risk factors e.g. hypertension
- AAA >6cm or expand at >1cm per year
- Surgery
Name 4 indications for AAA EVAR (endovascular aneurysm repair)
- Rapid expansion over 1cm a year
- Onset of sinister symptoms such as back or abdominal tenderness
- AAA >6cm
- High risk patients e.g. CKD
Describe the presentation of popliteal aneurysms?
- Often asymptomatic.
- Main risk is that there is embolisation of a thrombus from the aneurysm causing acute limb ischaemia
- Can also rupture however this is less common
- 10 % of pts with AAA will have popliteal aneurysm
Describe the management of popliteal aneurysms?
Treated even if asymptomatic due to risk of embolisation. Endovascular graft OR bypass surgery
Define a true aneurysm?
An aneurysm is a 50% increase of the normal diameter of an artery
True aneurysm = all layers of the arterial wall are involved
What is a false aneurysm?
Also known as a pseudoaneurysm.
The surrounding soft tissues lined by thrombus form the wall of the aneurysm, mainly following trauma
Outline the pathophysiology of a arterial aortic dissection?
- A tear in the intima leads to blood tracking into the arterial media
- The arterial media splits, forming a false channel
- This most commonly occuris in th aorta
Possible outcomes of aortic dissection?
External rupture: Massive fatal haemorrhage
Internal rupture: Rare, blood tracks into the lumen to produce a double-channelled aorta
Cardiac tamponade: retrograde spread into the pericardial cavity
