Aortic Disease Flashcards
What are the component parts of the aortic root
What are the layers of the aortic wall
Tunica intima
Tunica media
Tunica adventitia
Describe the tunica intima
Layer of endothelial cells
Subendothelial layer – collagen and elastic fibres
Separated from tunica media internal elastic membrane
Describe the tunica media
smooth muscle cells
secrete elastin in the form of sheets, or lamellae
Describe the tunica adventita
Thin CT layer
Collagen and elastic fibres (not lamellae)
Collagen prevents elastic arteries from stretching beyond their physiological limits during systole
What is an aneurysm
localised enlargement of an artery caused by weakening of vessel wall
What are the different types of aneurysm
True aneurysm - saccular, fusiform
False aneurysm, Dissecting aneurysm
What is a true aneurysm
Weakness & dilation of wall
Involves all 3 layers
What is a true aneurysm associated with
- Hypertension
- Atherosclerosis
- Smoking
- Bicuspid aortic valve
- Collagen abnormalities (Marfan’s)
- Infection (mycotic/syphillis)
- Trauma
What is a false aneurysm
Rupture of wall of aorta with haematoma either contained by thin adventitial layer or by surrounding soft tissue
What is the aetiology of false aneurysm
- Trauma
- Iatrogenic
- Inflammation ( eg endocarditis with septic emboli)
What are the different sites of aneurysms
Normal
Asceding aortic aneurysm
Aortic arch aneurysm
Descending aortic aneurysm
Abdominal aortic aneurysm
What are the signs and symptoms of aneurysms
Asymptomatic
Based on location of aneurysm.
* SOB (associated aortic regurgitation)
* Dysphagia and hoarseness
* Back pain
* Symptoms of dissection - sharp chest pain radiating to back (between shoulder blades), hypotension
* Pulsatile mass
What are the investigations for thoracic aortic aneurysms
CXR – widened mediastinum
Echocardiogram – assess aortic root size and aortic valve (limited views of distal ascending aorta and arch)
CT angiogram aorta – diagnostic
MRI aorta – diagnostic and follow-up
Other tests: TOE and invasive aortogram – rarely done
What is an aortic dissection
Tear in the inner wall of aorta
Blood forces walls apart
Acute –medical/surgical emergency
Chronic
What is the aetiology of dissections
Hypertension
Atherosclerosis
Marfan’s syndrome
Bicuspid aortic valve
Trauma
What is the histology of a dissection
cystic medial necrosis
False lumen can progress in antegrade or retrograde direction
What is the consequnces of dissections
May occulde branches
Rupture - back into lumen, externally into mediastinum or pericardium (temponade)
Dilation of acsending aorta may cause acute aortic regurgitation
What is the Stanford classification of dissections
Type A
Type B
What is type A dissection
All dissections involve acsending aorta, regardless of site of origin
What is type B dissection
All disections not involving acsending aorta
What are the symtpoms of dissection
Chest pain – severe, sharp, radiating to back (inter-scapular)
Collapse (tamponade, acute AR, external rupture)
Stroke (involvement of carotid arteries)
What is the examination (signs) for dissection
Reduced/absent peripheral pulses
Hyper or hypotension
BP mismatch between sides
Soft early diastolic murmur (aortic regurgitation)
Pulmonary oedema
Signs of CVA
What are the investigations for dissection
ECG
CXR
Transthoracic echogardiogram (TTE)
CT angiogram aorta
