Aortic Disease Flashcards
What is the basic histology of the tunica intima?
Layer of endothelial cells
Subendothelial layer - collagen and elastic fibres
Separated from the tunica media by internal elastic membrane
What is the basic histology of the tunica media?
Smooth muscle cells
Secrete elastin in the form of sheets or lamellae
What is the basic histology of the tunica adventitia?
Thin connective tissue layer
Colagen fibres and elastic fibres
The collagen in the adventitia prevents elastic arteries from stretching beyond their physiological limits during systole
When does atherosclerosis begin?
In early childhood
What are the risk factors for atherosclerosis?
Hypertension Hypercholesterolaemia Smoking Diabetes Family history Male
What are the possible outcomes of atherosclerosis?
Stroke
MI (ischaemia and infarction)
Aneurysm
What is an aneurysm?
A localised enlargement of an artery caused by a weakening of the vessel wall
What are the features of a true aneurysm?
Weakness and dilatation of the wall involving all 3 layers
Associated with hypertension, atherosclerosis, smoking and collagen abnormalities
Also associated with trauma and infection
What are the features of a false aneurysm
Rupture of the wall of the aorta with the haematoma either contained by the thin adventitial layer or by the surrounding soft tissue Inflammation Thrill Bruit Pulsatile mass Ischaemia Rupture
What are the signs and symptoms of thoracic aneurysms?
Asymptomatic
Based on location of the aneurysm
Dyspnoea or heart failure
Dysphagia and hoarseness
Sharp chest pain, radiating to back/between shoulder blades
Pulsatile mass felt on abdominal examination
Hypotension
What is an aortic dissection?
Tear in the inner wall of the aorta
Blood forces the walls apart
Acute is a medical emergency
What are the aetiological factors that cause aortic dissection?
Hypertension
Atherosclerosis
Trauma
Marfan syndrome
What is seen on histology of a patient with aortic dissection?
Cystic medial necrosis - loss of elastin and muscle fibres in the media with accumulation of mucopolysaccharides in cyst-like spaces
What directions can false lumens progress in?
Antegrade or retrograde
Where might an aortic dissection rupture?
Back into the lumen or externally into the pericardium or mediastinum
What might dilatation of the ascending aorta cause?
Acute aortic regurgitation
What is the DeBakey type I aortic dissection?
Originates in the ascending aorta and propagates at least to the aortic arch and often beyond it distally
What is the DeBakey type II aortic dissection?
Originates in and is confined to the ascending aorta
What is the DeBakey type III aortic dissection?
Originates in the descending aorta and extends distally down the aorta or rarely retrograde into the aortic arch and ascending aorta
What is the Stanford type A aortic dissection?
All dissections involving the ascending aorta, regardless of the site of origin
What is the Stanford type B aortic dissection?
All dissections not involving the ascending aorta
What are the symptoms and signs of aortic dissection?
Tearing, severe chest pain radiating to the back
Collapse - tamponade, acute rupture, external rupture
Inferior ST elevation
What is the mortality of aortic dissection pre-hospital?
Around 50%
What might be seen on examination of a patient with aortic dissection?
Reduced or absent peripheral pulses, BP mismatch between sides Hypotension/hypertension Soft early diastolic murmur Pulmonary oedema CXR usually shows widened mediastinum
