PVD Flashcards
definition of PVD
Peripheral arterial disease (PAD) includes a range of arterial syndromes that are caused by atherosclerotic obstruction of the lower-extremity arteries.
a narrowing or occlusion of the peripheral arteries, affecting the blood supply to the lower limbs.
acute limb ischemia
a sudden decrease in limb perfusion that threatens limb viability. In acute limb ischaemia, decreased perfusion and symptoms and signs develop over less than 2 weeks - vascular emergency in which the arterial blood supply to one or more extremities is critically reduced (no collateral vessels = emergency)
critical limb ischemia
when circulation is so severely impaired that there is an imminent risk of limb loss (collaterals)
chronic limb ischemia
chronic inadequate tissue perfusion at rest, ischemic rest pain with or w/o tissue loss (eg ulcer, gangrene or infection)
aetiology of PVD
can be
- embolic in origin with a cardiac source (AF)
- thrombosis in situ
- graft/angioplasty occlusion
- trauma
thrombi are most likely known in vasculopaths
emboli are sudden - in those w/o previous vessel disease
most common cause of PVD is atherosclerosis
RF of PVD
smoking - most powerful predictor, risk for atherosclerosis which is most common cause of PVD
dm
hypertension
hyperlipidaemia
>40yrs
history of coronary artery disease/CVD
low levels of exercise
aetiology of PAD
atherosclerosis = stenosis of the arteries
multifactoral process
limits blood flow to limb
less common causes:
- inflamm disorders eg vasculitis
- non-inflamm arteriopathies eg fibromuscular dysphagia
RF for PAD
modifiable and non-modifiable
- 65% have coexisting clinically relevant cerebral or coronary artery disease
- smoking - one of strongest RF (at least doubles risk), if continue to smoke more likely get claudication and critical limb ischemia and need amputation
- dm - especially severe, uncontrolled, longstanding. Have worse outcomes
- age
- hypertension
- hypercholesterolaemia
- known atherosclerotic disease elsewhere
- CKD - especially end stage needing dialysis
- high serum homocysteine
odds increase with number of RF
not all people with ACL have risk factors
aetiology of chronic limb threatening ischemia
thromboembolism
Buerger’s disease
trauma
dissection
physiological entrapment syndrome
cystic adventitial disease
aetiology of acute limb ischemia
sudden reduction in arterial perfusion
thrombosis when atherosclerotic plaque ruptures - more likely in vasculopaths
emboli - sudden
less common causes
- cardiac embolisation
- aortic dissection or embolisation
- graft thrombosis
- thrombosis of popliteal aneurysm
- trauma
- hypercoagulable states
- iatrogenic complications of vascular interventions
epidemiology of pvd
prevalence = 10%
globally over 200 million people have peripheral arterial disease
decreasing prevalence - increased uptake of secondary prevention strategies
asymptomatic PAD is more common than intermittent claudication
Chronic limb-threatening ischaemia has a reported prevalence of around 1–2% (may be more than 10% in people known to have peripheral arterial disease)
Acute limb ischaemia has an estimated incidence of 1.5 cases per 10,000 people per year - but it is a frequently missed or delayed diagnosis
sx of pvd
painful cold leg
wake with a severe dull ache in calf and foot that hasnt been helped by co-codamo
cramping pain on the calf, thigh or buttock after walking for a given distance (the claudication distance) and relieved by rest
calf claudication suggests femoral disease while buttock claudication suggests iliac disease
ulceration
gangrene - Tissue loss usually affects the toes.
foot pain at rest - burning pain at night (decrease in blood pressure when asleep and the loss of beneficial gravitational effects on lower limb circulation.) relieved by hanging legs over the side of the bed - feature of critical ischemia
buttock claudication +- impotence imply leriche’s syndrome
fontaine classification of PAD
- Asymptomatic.
- Intermittent claudication.
- Ischaemic rest pain.
- Ulceration/gangrene (critical ischaemia).
suspect acute ischemia:
sudden onset leg pain
sudden deterioration in claudication associated with loss of pulse and pallor
coldness
cyanosis of limb
suspect chronic limb ischemia
progressive development of cramp like pain in calf, thigh buttock on walking
unexplained foot or leg pain
non-healing wounds on lower limb
some people present with atypical symptoms, and may use terminology such as ‘tired’, ‘giving way’, ‘sore’, and ‘hurts’, rather than describing cramp.
where do sx of critical limb ischemia start
distally
signs of acute limb ischemia
- reduced or absent pulses
- cool skin temperature
- erythema
- skin pallor
- muscle weakness
- reduced sensation
if 6Ps (pale, pulseless, painful, paralysed, paraesthetic and perishing with cold)
fixed skin mottling indicates irreversible limb ischemia
limb may be erythematous when dependent but becomes pale when elevated
irregularly irregular pulse potentially indicates cause
may be bruit
in patients with known PAD, sudden deterioration of symptoms with deep duskiness of the limb may indicate acute arterial occlusion - This appearance is due to extensive pre–existing collaterals and must not be misdiagnosed as gout/cellulitis.
signs of PVD from emboli
acute
limb white - no collaterals
vascular exam of other limb = normal
signs of acute limb ischemia from thrombosis
gradual
symptoms less severe - due to collateral circ - often well developed in chronic peripheral vascular disease (in vasculopaths)
Presentation is usually with worsening claudication and rest pain.
Pulses in the other leg may also be absent.
signs of chronic limb ischemia
hairless skin
ulcers
Lipodermatosclerosis is a brown discolouration of hard skin with fibrotic subcutaneous tissues seen in chronic venous insufficiency (which may co-exist with arterial disease).
signs of PVD
absent pulses
cold
white
atrophic skin
punched out ulcer - often painful
postural/dependant colour change
Buerger’s angle (angle that leg goes pale when raised off bed) of <20degrees
cap refill >15sec
PVD Hx
presence of risk factors
asymptomatic
intermittent claudication - assess patients with detailed questions on walking impairment, claudication symptoms, ischaemic rest pain, or presence of non-healing wound/foot ulcer
thigh or buttock pain with walking that is relieved on rest - Intermittent claudication can also occur in the larger muscle groups of the upper leg. This is indicative of narrowing of the deep femoral artery or aorto-iliac level disease.
diminished or absent pulse
Ix for PVD
exclude DM, arthritis (ESR/CRP)
FBC - anaemia/polycythaemia
U&E - renal disease
ECG - cardiac ischemia
thrombophilia screen adn serum homocysteine if <50yrs
ankle brachial pressure index
imaging
ABPI for PVD
Normal =1–1.2;
PAD=0.5–0.9;
critical limb ischaemia <0.5 or ankle systolic pressure <50mmHg.
Beware falsely high results from incompressible calcified vessels in severe atherosclerosis, eg DM.
imaging for PVD
colour duplex US - 1st line
- diminished or absent doppler flow signal distal to the site of occlusion
if considering intervention - MR/CT angiogrpahy for extent and location of stenoses and quality of distal vessels (run-off)
echocardiography if arterial embolism is suspected
