Aneurysms Flashcards
Define an aneurysm
A permanent and irreversible dilatation of a blood vessel >150% the expected diameter
How can aneurysms present?
Mass effects
Embolic events
Haemorrhag3e
What are the causes of an aneursym?
Atherosclerotic (aortic, popliteal) Developmental (berry) Infective (mycotic, syphillitic) Developmental (marfans) Trauma
What are the common sites for arterial aneurysms?
Aorta (most commonly infrarenal) Iliac Thoracic Coronary Cerebral Femoral Popliteal
What is the pathophysiology underlying a thoracic aortic dissection?
Blood splits aortic media
As dissection extends branches occlude sequentially, causing Sx
What are the main symptoms of thoracic aortic dissection?
Sudden tearing chest pain (radiation to back) Hemiplegia/Paraplegia Unequal pulses/BP Acute limb ischaemia Anuria
What arteries are occluded, leading to the symptoms of a thoracic aortic dissection?
Coronary - MI Brachiocephalic Trunk - Hemiplegia, central neuro sx Renal - Haematuria, anuria, AKI SMA/IMA - Acute mesenetric ischaemia Iliac - Acute lower limb ischaemia
What are the major complications of a thoracic aortic dissection?
External rupture - massive fatal haemorrhage
Internal rupture - blood tracks back into lumen, double channelled aorta
Cardiac tamponade
When can complications of a thoracic aortic dissection occur?
If dissection moves proximally
What is the mortality of a thoracic aortic dissection?
Acute operative mortality = 25%
75% w/i 2 weeks untreated`
What are the symptoms/signs of a ruptured abdominal aortic aneurysm?
Intermittent/continuous epigastric pain -radiates to back/iliac fossae/groins Collapse Pulsatile, expansile abdominal mass Shock
What is an Abdominal Aortic Aneurysm?
Dilation of abdominal aorta to >3cm
What is surveillance monitoring of AAA?
Regular ultrasound Small aneurysms (<5.5cm) monitored Larger aneurysms (>5.5cm) considered for surgery
Why do we monitor rather than repair all AAAs?
No evidence for early benefit in small aneurysms where rupture risk is low
How regularly do we monitor AAAs?
Depends on diameter of aneurysm at detection
3-4cm (annually)
4.5-5.4 (3 monthly)
>5.5 (consider surgery, 3 monthly)
What are the risk factors for rupture?
HTN
Family history
Smokers
Females
What is the emergency management of an AAA?
A-E resuscitation
Clamp aorta above leak and insert graft (theatre)
What is the mortality of a rupture AAA?
50% die before reaching hospital
50% of those who do die in theatre
What are the indications for surgical management of an unruptured AAA?
> 6cm
Expanding >1cm/yr
Symptomatic aneurysms
How are unruptured AAAs repaired?
Endovascular aneurysm repair (EVAR)
-fluoroscopic surgery
What is a major risk of EVAR?
CKD, contrast nephrotoxic and prolonged ischaemia due to aorta clamping during surgery
How do popliteal aneurysms present?
Associated w/ other aneurysms
Asymptomatic OR:
-Acute limb ischaemia
-Distal emboli (chronic limb ischaemia, DVT)
How should popliteal aneurysms be investigated?
USS
Angiography
How should popliteal aneurysms be managed?
Femoral to distal popliteal bypass grafts
