Aortic Disease Flashcards
(30 cards)
What does tunica intima consist of?
Layer of endothelial cells
Subendothelial layer – collagen and elastic fibres
Separated from tunica media internal elastic membrane.
What does tunica media consist of?
smooth muscle cells
secrete elastin in the form of sheets, or lamellae
What does tunica adventitia consist of?
Thin connective tissue layer
Collagen fibres and elastic fibres (not lamellae)
The collagen in the adventitia prevents elastic arteries from stretching beyond their physiological limits during systole
risk factors for atherosclerosis?
Hypertension
Hypercholesterolaemia
Smoking
Diabetes
Family history
Male>female (relative protection in females until menopause)
What does atherosclerosis commonly cause?
Myocardial infarction
Stroke
Peripheral vascular disease
Aneurysm
What is an aneurysm?
A localised enlargement of an artery caused by a weakening of the vessel wall
What are the classifications of aneurysms?
True aneurysms- saccular and fusiform
false aneurysm- had rupture and rupture contained ( clot, ruptured into fibrous tissue)
Dissecting aneurysm- tear in layer
Difference between true and false aneurysm?
TRUE;
Weakness & dilation of wall
Involves all 3 layers
Associated with:
Hypertension
Atherosclerosis
Smoking
Bicuspid aortic valve
Collagen abnormalities (Marfan’s)
Infection (mycotic/syphillis)
Trauma
FALSE:
Rupture of wall of aorta with the haematoma either contained by the thin adventitial layer or by the surrounding soft tissue
Aetiology:
Trauma
Iatrogenic
Inflammation ( eg endocarditis with septic emboli)
Classification of aortic aneurysm by site?
normal
ascending aortic arch
descending
abdominal
Signs and symptoms of thoracic aneurysms?
Asymptomatic
Based on the location of the aneurysm.
Shortness of breath (associated aortic regurgitation)
Dysphagia and hoarseness
Back pain
Symptoms of dissection - sharp chest pain radiating to back (between shoulder blades), hypotension
Pulsatile mass
Investigations for thoracic 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 (takes too long)
Other tests: TOE and invasive aortogram – rarely done
What is aortic dissection?
Tear in the inner wall of aorta
Blood forces walls apart
Acute –medical/surgical emergency
Chronic
Aetiological factors of dissection?
Hypertension
Atherosclerosis
Marfan’s syndrome
Bicuspid aortic valve
Trauma
Characteristics of dissection?
Histology- Cystic medial necrosis
False lumen can progress in an antegrade or retrograde direction
May occlude branches (e.g. coronary, mesenteric, carotid, renal, spinal)
Rupture - back into the lumen or externally in to pericardium (tamponade) or mediastinum
Dilation of ascending aorta may cause acute aortic regurgitation
Classification of thoracic aortic dissection?
Symptoms of thoracic dissection?
Chest pain – severe, sharp, radiating to back (inter-scapular)
Collapse (tamponade, acute AR, external rupture)
Stroke (involvement of carotid arteries)
Examination findings for aortic dissection?
Reduced or absent peripheral pulses
Hypertension or hypotension
BP mismatch between sides
Soft early diastolic murmur (aortic regurgitation)
Pulmonary oedema
Signs of CVA
Investigation Aortic Dissection?
ECG – might show ST elevation/ischaemia indicating coronary involvement
CXR - widened mediastinum
Transthoracic echocardiogram (TTE) – assess aortic root (limited views), aortic regurgitation? pericardial effusion ?
CT angiogram aorta - confirms diagnosis (MOST COMMON)
~ 50% mortality pre-hospital
Type A and Type B treatment?
Type A
Blood Pressure control
beta blocker, IVI nitrate, calcium channel blocker, IVI Sodium nitroprusside
Emergency Surgery
Type B
Blood pressure control
beta blocker, IVI nitrate, calcium channel blocker, IVI Sodium nitroprusside
Percuraneous (endo-vascular) intervention
What is Takayasu’s Arteritis?
Granulomatous vasculitis
Females>Males
Aorta & main branches
Stenosis, thrombosis, aneurysms, renal artery stenosis, neurological sx
Steroids and immunosuppressive Tx
Surgery and percutaneous intervention may be required
Syphyllis caused by, bacteria that causes and treatment?
STD
Treponema pallidum
Antibiotics prevent late stages
Tertiary syphillus?
Without treatment – 1/3rd develop 1 of 3 types
Late neuro-syphillis
Gummatous syphillis
Cardiac syphillis
Cardiac syphillis (10-30yrs post infection)
Syphilitic aortitis – aneurysm
Aortic regurgitation
Congenital aortic aneurysm?
Bicuspid Aortic Valve
Coarctation
Marfan’s Syndrome
Characteristics of bicuspid aortic valve?
Most common congenital abnormality
1-2% prevalence
Prone to aortic valve stenosis +/- regurgitation
Associated with coarctation
Abnormal aorta (reduced tensile strength)
Prone to aneurysm/ dissection
Monitor with echo/ MRI
