Arterial Disease and Aneurysms Flashcards
List some causes of arterial occlusion
Atherosclerosis Embolism (cardiac, arterial to arterial) Pro-coagulant state Low flow state Thrombosed aneurysm Dissection Fibro-muscular hyperplasia Arteritis Entrapment Adventitial cysts
Define claudication
Ischaemic pain in exercising muscles due to imbalance between workload of muscles and ability to maintain aerobic metabolism (angina of the legs)
Describe the pathophysiology of claudication
Posterior calf muscles dominate with walking
When flow of oxygenated blood is inadequate, muscles switch to anaerobic metabolism to meet energy demands
Lactic acid builds up and produces aching discomfort
Eases with rest
What are the clinical criteria for claudication?
Calf pain on exertion (+/- thigh, +/- buttock)
Onset and severity related to workload
Relieved with rest
Reproducible
Where does ischaemic rest pain occur?
Most distal part of the limb
Describe the pathophysiology of ischaemic rest pain
Inadequate perfusion resulting in anaerobic metabolism in skin and nerves (cf muscles) of the extremity
How is ischaemic rest pain defined clinically?
Burning pain in extremity at rest (often wakes patient in the night)
Usually relieved with gravity
What are the features of critical limb ischaemia (CLI)?
Ischaemic rest pain
Ulcers
Gangrene
At what ankle and toe pressure does rest pain occur?
Ankle pressure
At what ankle and toe pressure do ulcers/gangrene occur?
Ankle pressure
What is the trans-cutaneous O2 pressure in CLI?
What are some possible patterns of lower limb occlusive disease?
Aorto-iliac (inflow)
Femoro-popliteal (outflow)
Tibial/crural
What are the features of aorto-iliac occlusive disease?
Calf, thigh and buttock claudication
Reduced pulses femoral and below
May be bruits over aorta/iliac
What are the features of femoro-popliteal occlusive disease?
Calf claudication
Reasonable femoral pulse but weak or absent popliteal and pedal pulses
Bruit along line of femoral or popliteal arteries
What are the features of tibial/crural occlusive disease?
May be no claudication
Reasonable popliteal pulses but absent pedal pulses
Bruits over popliteal or upper tibial arteries
Describe the epidemiology of peripheral arterial disease
12% of adult population and 20% of population >70 years
Associated with 6-fold increase in CV mortality (patients at high risk need aggressive risk-factor modification and antiplatelet drugs)