Aortic Disease Flashcards
What is an aortic aneurysm?
Dilation/localised enlargement of all layers of the aorta, leading to an increase in diameter of >50%, caused by weakening of the vessel wall
How quickly to aortic aneurysms grow?
Aneurysms grow approx 2mm a year and as it gets bigger, the walls get thinner
Name the 3 layers of the aorta
Tunica externa
Tunica media
Tunica intima
What is a ‘true’ AAA?
Weakness and dilation of wall that involves all 3 layers
What is a ‘false’ AAA?
Not all layers are dilated, rupture contained by adventitial layer
What term is used to describe a AAA on one side?
Saccular
What term is used to describe a AAA on both sides?
Fusiform
What are the causes of AAA?
Degenerative disease/atherosclerosis
Connective tissue disease/hyper-elasticity conditions
- Ehlers Danlos
- Marfan’s syndrome
Syphilis
Name some risk factors for AAA
M>F
>Age
Smoking
HTN
FH
How does an AAA present?
Back/abdomen pain
Painful pulsatile abdominal mass
Sharp angina
- Radiating to the back between shoulder blades
Dyspnoea
Hoarseness
Haemodynamic instability/shock
- Tachycardia
- Hypotension
Name some complications of an AAA
Distal embolisation
Hypoperfusion/inadequate perfusion to tissues
Aortocaval or Aortoenteric fistula
Ureteric occlusion
What investigations are used in AAA diagnosis?
US
CT
- Ruptured AAA are diagnosed clinically as patients do not have time for a CT to confirm diagnosis
Describe the AAA screening programme
Single abdominal US for males 65
If aorta is less than 3cm/normal, no further action is taken
How many cm is a normal aorta?
<3cm
How many cm is a small AAA?
3-4.4cm
How many cm is a medium AAA?
4.5-5.5cm
How many cm is a large AAA?
>5.5cm
How often do patients with a small AAA go for US?
Rescan annually
How often do patients with a medium AAA go for a US?
Rescan every 3 months
What size does an AAA have to be to be considered for surgery?
>5.5cm
What is a low rupture risk AAA?
Asymptomatic
Aortic diameter < 5.5cm (i.e. small and medium aneurysms)
What is a high rupture risk AAA?
Symptomatic
Aortic diameter >=5.5cm or rapidly enlarging (>1cm/year)
What is the management of a low rupture risk AAA?
Abdominal US surveillance
Optimise cardiovascular risk factors
What is the management of a high rupture risk AAA?
Refer within 2 weeks to vascular surgery
Elective endovascular repair (EVAR), in which stent is placed into the abdominal aorta via the femoral artery
Open repair if unsuitable for EVAR
Give a complication of EVAR
Endo-leak, where the stent fails to exclude blood from the aneurysm, presenting without symptoms on routine follow up
What is the management of a ruptured AAA?
Immediate vascular review and emergency surgical repair
What is an aortic dissection?
Tear in the inner wall of the aorta (tunica intima) resulting in the redirection of blood flow
What are the causes of an aortic dissection?
HTN
Trauma/Surgery
Atherosclerosis
Marfan’s/connective tissue disorders
Pregnancy
Turners and Noonans
Syphillis
Aneurysms
Bicuspid aortic valve
How does an aortic dissection present?
Tearing chest pain
- Anterior if ascending aorta
- Back pain if descending
- Very similar to MI
Collapse
Radial-radial delay
Abscent femoral pulse
Auscultation
- Soft early diastolic murmur, aortic regurgitation
Neurological symptoms
What investigations are used in the diagnosis of an aortic dissection?
CXR
- Widened mediastinum
CT of chest, abdomen and pelvis
- Tennis ball sign
- Contrast shows true lumen as white while false lumen is grey due to fibrosis
Transoesophageal echocardiography (TOE)
- More suitable for unstable patients who are too risky to take to CT scanner
What classification is used in aortic dissections?
Sandford
What are the two classifications of aortic dissections?
A
- Involves the ascending aorta
B
- Descending aorta, distal to left subclavian origin
What is the management of an aortic dissection?
Type A
- Aortic root replacement and IV labetolol
Type B
- HTN control/IV Labetalol
Give complications of aortic dissections
Backward tear
- Aortic regurgitation
- MI
Forward tear
- Stroke
- Renal failure
