Arterial Disease and Aneurysms Flashcards
What are the possible sources of a cardiac embolus?
Atrial fibrillation
Infective endocarditis
Left ventricular aneurysm
What is a possible source of an arterial to arterial embolus?
Thrombus in proximal larger vessel, most commonly ascending aorta
What are some pro-coagulant states that can cause an arterial occlusion?
Pregnancy
Malignancy
Inherited disorders
What are some low flow states that can cause an arterial occlusion?
Severe heart failure
Hypotension
Dehydration
What are the possible causes of an arterial occlusion?
Athero-thrombus Embolism Pro-coagulant state Low flow state Thrombosed aneurysm Dissection Fibromuscular hyperplasia Arteritis Entrapment = compartment syndrome Adventitial cysts
What is fibromuscular hyperplasia?
Congenital anomaly of vessel wall, affecting small to moderate sized muscular arteries
What are adventitial cysts?
Rare condition where cysts form in artery and narrow/occlude blood flow
What is claudication?
Ischaemic pain in exercising muscles
Imbalance between workload of muscles and ability to maintain aerobic metabolism
What metabolite builds up in claudication?
Lactic acid
How is claudication clinically defined?
Calf +/- thigh +/- buttock pain on exertion
Onset and severity related to workload
Relieved with rest
Reproducible
What is Leriche syndrome?
Claudication in common iliac artery causing claudication in - Buttocks - Thighs - Calves Can commonly get erectile dysfunction Common in diabetes
Where does ischaemic rest pain occur?
Most distal part of limb
What does ischaemic rest pain imply?
Perfusion so poor that anaerobic metabolism present in skin and nerves of extremity
What is a common presentation of ischaemic rest pain?
Foot perfusion aided by gravity
Patients wake with burning pain in extremity
Sit up and hang feet over edge of bed for relief
In worse case, spend all night sleeping in chair
What are the patterns of lower limb occlusive disease?
Aorto-iliac
Femoro-popliteal
Tibial/crural
What is the presentation of an aorto-iliac occlusive disease pattern?
Claudication - Calf - Thigh - Buttock Pulses - Reduced femoral and below ?Bruit over aorta/iliac artery
What is the presentation of a femoro-popliteal occlusive disease pattern?
Claudication - Calf Pulses - Reasonable femoral - Weak/absent popliteal and pedal pulses Bruit along line of femoral/popliteal arteries
What is the presentation of a tibial/crural occlusive disease pattern?
Claudication - May be none Pulses - Popliteal reasonable - Pedal pulses absent Bruit over popliteal/upper tibial arteries
What are the considerations that need to be made when managing claudication?
Reasonable distance claudication benign - limb not in jeopardy
Any intervention or artery = controlled injury
Intervention may not work
Intervention may not be durable
When may an intervention for claudication be reasonable?
Claudication very significant handicap
Otherwise acceptablee risk
Proposed intervention has acceptable chance of working
What are the interventions available for claudication?
Angioplasty +/- stenting
Endarterectomy
Bypass
When is angioplasty +/- stenting best?
Short segments
Proximal arteries
When is endarterectomy best?
Short segments
When is bypass best?
Longer blocks
What are the characteristics of a nonviable limb?
Signs of
- Tissue loss
- Nerve damage
- Sensory loss
What is the management of a nonviable limb?
Not much can do medically
Nave to surgically remove it
What are the characteristics of a viable limb?
No significant
- Tissue loss
- Nerve damage
- Sensory loss
What is the management of a viable limb?
Define arterial anatomy with CT/MRI
Urgent revascularisation
Arterial thrombolysis as good as mechanical embolectomy
What are the indications for revascularisation?
Lifestyle limiting claudication with no improvement with exercise program
Critical limb ischaemia symptoms
Acute limb ischaemia
What is the management of claudication that is not lifestyle limiting?
Risk factor modification Annual followup to include monitoring for - Coronary artery disease - Cardiovascular disease - Ischaemic leg
What is the management of claudication that is lifestyle limiting?
Symptom relief
Physical therapy
What are the six Ps of an ischaemic limb?
Pain Pallor Paralysis Pulse deficit Parasthesia Poikilothermia
How does an ischaemic limb present?
Sudden onset of 6 Ps
Later pain in extremity lessens as nerve function ceases due to ischaemia
What is an aneurysm?
Consequence of atherosclerosis
Focal arterial dilatation
1.25-1.5 greater diameter than adjacent normal artery
Degenerative
What is the natural history of an aneurysm?
Continued expansion
Eventual rupture
What lines an aneurysm?
Thrombus
What is the commonest presentation of a burst abdominal aortic aneurysm?
Common in males >60 Abdominal pain Sometimes radiates to back Collapse Pulsatile mass in abdomen on palpation
What is the pathology of an aneurysm?
In media and adventitia
- Destruction of elastin
- Eventual failure of collagen
Local inflammation
What is the primary prevention for aneurysms?
Cease cigarette smoking
Control hypertension
What is the secondary prevention for the rupture of aneurysms?
Screening and treatment of aneurysms >5-5.5 cm
What is the treatment approach for peripheral vascular disease?
All patients regardless of symptoms should have aggressive risk factor modification
- Reduce blood pressure
- Reduce LDLs
- Smoking cessation
- Anti platelet therapy
- Aspirin
- Clopidogrel
What imaging technique can detect aneurysms?
Doppler ultrasound
How much fluid should be given to someone with a ruptured abdominal aortic aneurysm and why?
No more than 3.5 L otherwise increase risk of mortality
Because increase risk of cardiac output > more blood out of rupture, and colloids used have anticoagulant property
If person comes in unconscious, don’t bother with fluids
