Aortic Dissection Flashcards
(24 cards)
What is aortic dissection?
A condition where a tear in the aortic intima allows blood to surge into the aortic wall, causing a split between the inner and outer tunica media, and creating a false lumen
intima tear -> blood flows in aortic wall -> creates false lumen by splitting the inner and outer tunica media
Risk factors for aortic dissection?
Hypertension Aortic atherosclerosis Connective tissue disease (e.g. SLE) Congenital cardiac abnormalities (e.g. aortic coarctation) Aortitis Iatrogenic (e.g. angiography/angioplasty) Trauma Crack cocaine
Types of aortic dissection and defining features?
Type A = Ascending aorta tear (most common)
Type B = descending aorta tear distal to the left suBclavian artery (past end of the aortic arch)
Which arteries may be obstructed by aortic dissection (false aneurysm)?
Subclavian Carotid Coronary Coeliac Renal
Age group/sex most common for aortic dissection incidence?
40-60 years
Males
Presentation of aortic dissection?
Sudden, central ‘tearing’ pain
- this may radiate to the back
Aortic dissection can lead to occlusion of the aorta and its branches so SYMPTOMS MAY RELATE to the affected artery(s)
Carotid obstruction, secondary to aortic dissection, symptoms?
Hemiparesis
Dysphasia
Blackout
Coronary artery obstruction, secondary to aortic dissection, symptoms?
Chest pain (angina or MI)
Subclavian artery obstruction, secondary to aortic dissection, symptoms?
Ataxia
Loss of consciousness
Anterior spinal artery obstruction, secondary to aortic dissection, symptoms?
Paraplegia
Coeliac trunk obstruction, secondary to aortic dissection, symptoms?
Severe abdominal pain - ischaemic bowel
Renal artery obstruction, secondary to aortic dissection, symptoms?
Anuria
Renal failure
Specific examination finding for aortic dissection?
Murmur on the back below left scapula, descending to abdomen
What non-specific examination findings might you find in aortic dissection?
Blood pressure
- hypertension/hypotension
- wide pulse pressure
Aortic insufficiency
- collapsing pulse
- unequal arm pulses
Which investigations are indicated in aortic dissection?
Bloods
CXR
CT-chest
Echocardiography
Which bloods are useful in investigation/management of aortic dissection?
- FBC
- Cross-match 10 units of blood
- U&Es (renal function)
- Clotting
Signs of aortic dissection on CXR?
- widened mediastinum
- localised bulge in the aortic arch
Signs of aortic dissection on CT chest?
false lumen of dissection can be visualised
Specificity of transoesophageal echocardiography in aortic dissection?
Highly specific
Acute management of aortic dissection?
- Fluid resuscitation with blood products
- CT-thorax urgently
- Monitor pulse/BP in both arms, central venous pressure, insert urinary catheter
Treatment of Type A aortic dissection?
Emergency surgery because of risk of cardiac tamponade
- affected aorta is replaced by a tube graft
Treatment of Type B aortic dissection?
Medical control of BP/reduction of further dissection - IV nitroprusside and/or IV labetalol (use CCB if beta-blocker contraindicated e.g. asthma)
Surgical repair - may be appropriate in more severe cases
Endovascular repair/stent
Complications of aortic dissection?
Aortic rupture, cardiac tamponade, pulmonary oedema, MI, syncope, and cerebrovascular/renal/mesenteric/spinal ischaemia (remember the arteries that can potentially become occluded)
Prognosis summary for aortic dissection?
Untreated mortality - 30% at 24h, 75% at 2 weeks
Operative mortality - 5-10%
Further 10% have neurological sequelae
Prognosis is better for type B than type A
