Vascular 2 Flashcards
What is the Fontaine Classification?
Fontaine: Outlines the progression of chronic limb peripheral arterial disease 1 - asymptomatic 2 - intermittent claudication 3 - ischaemic rest pain 4 - ulceration/gangrene
What ABPI values suggest PAD?
> 1.2: may indicate calcified, stiff arteries. This may be seen with advanced age or PAD
1.0 - 1.2: normal
0.9 - 1.0: acceptable
< 0.9: likely PAD. Values < 0.5 indicate severe disease which should be referred urgently
What does ABPI >1.2 signify?
May be a false negative due to calcification giving abnormally stiff vessels
More common in diabetics
What are the causes of ABPI >1.2?
Atherosclerosis: by far the most common
Fibromuscular dysplasia: non-inflammatory artery wall thickening
Buerger’s disease (thromboangiitis obliterans): acute inflammation and thrombosis of lower limb arteries/veins, common in young, heavy smokers
What are the symptoms of intermittent claudication?
Ischaemic ‘cramping’ muscle pain on walking, relived by rest
Pain reproducible at a similar level - ‘claudication distance’
most commonly in the calf, suggesting femoral disease
Pain in the thigh/buttock suggests ileal disease, which will often be bilateral
Ask about penile function - ‘Leriche syndrome’
What are the signs of intermittent claudication?
Absent pulses Cold, pale legs Atrophic, hairless and shiny skin Buerger's angle: <20 degrees: look for reactive hyperaemia arterial ulcers
What is ischaemic rest pain indicative of?
Critical lower limb ischaemia
What is the presentation of ischaemic rest pain?
Classically occurs at night in the forefoot - due to the decreased effects of gravity and decreased BP
Pain wakes a patient from sleep
They can gain relief by swinging the leg over the side of the bed or walking on a cold floor
History of intermittent claudication and signs of arterial insufficiency in the leg
Why are arterial ulcers more likely to be formed if there is ischaemic rest pain?
More likely to form from minor injuries as healing is impaired and infection of these ulcers can lead to rapidly spreading gangrene (more common in those with co-morbid diabetes)
What investigations are done for intermittent claudication/ischaemic rest pain?
Bloods: FBC (rule out anaemia: HbA1c, lipids
ABPI is the most important initial investigation
Management depends on ABPI result and level of symptoms
What is the management if ABPI >0.6?
Progression from intermittent claudication to critical ischaemia is unlikely, so conservative measures are used
Progression more likely in diabetics, and those with a claudication distance <50m
More aggressive treatment may be considered in these patients
What are the conservative measures for peripheral arterial occlusive disease?
Lifestyle changes: stop smoking, exercise to the point of claudication to improve collaterals, weight loss
Raising the heel of shoes (decreased calf work)
Foot care to prevent minor trauma leading to ulceration etc
Optimisation of blood pressure (avoid beta-blockers) and diabetes
Started on anti platelet (clopidogrel and a statin (atorvastatin)
What is the management if ABPI <0.6?
Highly symptomatic - leading to a loss of function, or conservative measures ineffective PTA surgical reconstruction sympathectomy amputation
What is PTA?
Percutaneous transluminal angioplasty
Balloon inflated in narrowed segment, good for short stenosis
Endoluminal stents may be used to keep the segment patent
What surgical reconstruction procedures are used for peripheral arterial occlusive disease?
Bypass grafting may be required in more extensive disease if distal arteries are not diseased, with saphenous vein harvests common
What are the indications for amputation?
May relieve intractable pain, and prevent death from septicaemia
Level of amputation must be high enough to ensure healing but above knee amputation has worse rehabilitation than below knee
Gabapentin started pre-op may help phantom limb pain
What is the effect of diabetes on peripheral arterial disease?
Diabetics are at a greater risk of developing peripheral arterial disease and presentation can be different due to the presence of peripheral neuropathy, which has three main effects:
sensory neuropathy
autonomic neuropathy
motor neuropathy
How does sensory neuropathy affect peripheral arterial disease?
reduces protective reactions to minor injury and reduces awareness of symptoms of infections / ischaemia
How does autonomic neuropathy affect peripheral arterial disease?
A lack of sweating leads to development of dry, fissured skin allowing entry of bacteria
How does motor neuropathy affect peripheral arterial disease?
Wasting of the small muscles of the foot - leading to loss of the arches and development of abnormal pressure areas in the feet
What is the difference between peripheral neuropathy and ischaemic rest pain?
Stabbing pains in feet
red and warm feet - STRONG pulses
Unlikely to be relieved by swing foot over bed/walking on a cold floor
How are diabetics with peripheral arterial disease likely to present
Can be severely ischaemic, but painleess
More likely to present with ulceration, due to the combination of sensory, autonomic and motor neuropathy combined with poor arterial supply to heal ulcers
This can rapidly progress to gangrene
What is gangrene?
Dead tissue, normally colonised by bacteria
Wet gangrene: infected with proliferating organisms
Dry gangrene: colonised, but organisms are not proliferating
Presents in the toes first, progressing proximally to line where there is adequate oxygenation
What is the appearance of gangrene?
Blue-purple in colour, with progressive blacking of tissues and numbness
What is the presentation of gangrene in diabetics?
In diabetics, usually presents earlier - affecting smaller areas e.g. a single toe, or ischaemic area of the heel
This is due to the more extensive atherosclerotic changes of smaller vessels seen in diabetes
Which area is most usually affected by intermittent claudication?
Calf - as it is the femoral Artery that most commonly becomes atheromatous
Why does intermittent claudication occur?
At rest, the oxygen requirement of muscles is met by the collateral system of the profonda femoris (deep femoral artery that joins the popliteal artery just below the knee)
Exercise produces a demand that cannot be met and the calf muscles become ischaemic
By resting, the collateral system can once again supply enough blood for the pain to be relieved
What are the ddx of intermittent claudication?
Spinal stenosis
venous claudication
What is the cause of spinal stenosis?
Spinal osteophyte formation
symptoms are due to lumbar nerve roots / cauda equina compression
What are the features of spinal stenosis?
features similar to intermittent claudication, but pain is relieved by sitting down or flexing the spine rather than standing still
Symptoms vary day to day
associated with numbness/tingling and pulses will be present
Diagnosis confirmed with MRI
What is the cause of venous claudication?
Obstruction of the venous outflow of the leg (ileofemoral occlusion)
Pain comes on gradually from the moment walking starts
Pain affects the whole leg, and is bursting in nature
leg elevation can relieve the pain
There are signs of venous disease and often a history of DVT
What are the other causes of leg pain?
intermittent claudication spinal stenosis venous claudication musculoskeletal (OA/RA) peripheral neuropaty popliteal artery entrapment - young patients with normal pulses
What proportion of leg ulcers are venous?
85%
many also have an arterial element
what is the cause of venous leg ulcers?
occur due to venous hypertension and oedema causing subcutaneous hypoxia
an episode of minor trauma then precedes development of an ulcer as the skin is poorly nourished and cannot heal
Secondary infections common
What is the cause of an arterial ulcer?
10% ulcers are entirely the consequence of arterial disease
occur after an episode of minor trauma, with inadequate healing due to poor arterial supply
Arterial vs venous ulcer: history
arterial: IC, IHD, HTN, DM
venous: DVT, varicosities, obesity
