Aortic dissection Flashcards
What is an aortic dissection?
tear in the intimal layer of the aortic wall causing blood to flow between and splitting apart the tunica intimal and media
When is an aortic dissection classed as acute or chronic ?
when diagnosed less then 14 days, or chronic if more than 14 days
Who are aortic dissections common in?
men and people with connective tissue disorders
How can aortic dissections progress?
initial intimal tears can progress distally, proximally or in both directions from the point of origin,
How do anterograde dissections propagate?
towards the iliac arteries
How to retrograde dissections propagate?
towards the aortic valve at the root of the aorta, this can therefore cause prolapse of the aortic calve and bleeding into the pericardium and cardiac tamponade
What is the DeBakey classification?
groups aortic dissections into 3 types
What is a type 1 in the DeBakey classification and who are they most common in ?
originates the ascending aorta and propagates at least to the aortic arch (usually under 65 and high mortality rate)
What is a type II DeBakey classification and who are they most common in?
confined to ascending aorta (usually see in elderly patients with atherosclerotic disease, hypertension)
What is the type III DeBakey classification?
originates distal to the subclavian artery in the descending aorta , IIIa extends to the diaphragm and b extends beyond the diaphragm and into the abdominal aorta
What is the stanford classification of aortic dissections?
divides into two groups A and B- A is Bebakeys I and II and involved the ascending aorta and can propagate to the aortic arch and descending aorta, the tear can originate anywhere along the path, Group B are type III DeBakeys, dissections do not involve the ascending aorta
What are the risk factors for aortic dissections?
Hypertension, atherosclerotic disease male gender, connective tissue disorders like Marfans or Ehlers Danlos, Biscupsid aortic valve
What are the symptoms of an aortic dissection?
tearing chest pain, radiating to the back, tachycardia, Hypotension, new aortic regurgitation murmur or signs of end organ hypo perfusion
What are some signs of end organ hypo perfusion?
reduced urine output, paraplegia, lower limb ischameia, abdominal pain secondary to ischaemia, deteriorating conscious level
What causes hypotension in an aortic dissection?
blood loss into the dissection or cariogenic from severe aortic regurgitation and pericardial tamponade
What are the differential diagnosis for an aortic dissection?
MI, pulmonary embolism, pericarditis, musculoskeletal pain
What are the investigations done for a suspected aortic dissection?
baseline blood tests such as FBC, U and E, LFTs, troponin and coagulation, crossmatch, arterial blood gas, ECG, CT angiogram as first line imaging, trans oesophageal ECHO can also be used
What is the management for aortic dissection?
high flow oxygen, IV access with 2x large bore cannulae, fluids, type A surgically, Type B medically managed, antihypertensives and surveillance
How are type A aortic dissections treated?
high mortality so usually removed the ascending aorta and replaces with synthetic graft, then nay additional branches od the aortic arch will require reimplanation into the graft
How are type b aortic dissections treated?
Medically, by managing hypertension with IV beta blockers or CCB, this will minimise the stress of the dissection and limit further propagation, due to risk fo retrograde dissection in surgery, medical management is the best option, surgery is needed in complications,
What are some complications of aortic dissections?
aortic rupture, aortic regurgitation, Myocardial ischaemia, cardiac tamponade, stroke, paraplegia, aneurysm formation
