PVD

Question 1

definition of PVD

Answer 1

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.

Question 2

acute limb ischemia

Answer 2

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)

Question 3

critical limb ischemia

Answer 3

when circulation is so severely impaired that there is an imminent risk of limb loss (collaterals)

Question 4

chronic limb ischemia

Answer 4

chronic inadequate tissue perfusion at rest, ischemic rest pain with or w/o tissue loss (eg ulcer, gangrene or infection)

Question 5

aetiology of PVD

Answer 5

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

Question 6

RF of PVD

Answer 6

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

Question 7

aetiology of PAD

Answer 7

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

Question 8

RF for PAD

Answer 8

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

Question 9

aetiology of chronic limb threatening ischemia

Answer 9

thromboembolism

Buerger’s disease

trauma

dissection

physiological entrapment syndrome

cystic adventitial disease

Question 10

aetiology of acute limb ischemia

Answer 10

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

Question 11

epidemiology of pvd

Answer 11

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

Question 12

sx of pvd

Answer 12

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

Question 13

fontaine classification of PAD

Answer 13

1. Asymptomatic.
2. Intermittent claudication.
3. Ischaemic rest pain.
4. Ulceration/gangrene (critical ischaemia).

Question 14

suspect acute ischemia:

Answer 14

sudden onset leg pain

sudden deterioration in claudication associated with loss of pulse and pallor

coldness

cyanosis of limb

Question 15

suspect chronic limb ischemia

Answer 15

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.

Question 16

where do sx of critical limb ischemia start

Answer 16

distally

Question 17

signs of acute limb ischemia

Answer 17

• 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.

Question 18

signs of PVD from emboli

Answer 18

acute

limb white - no collaterals

vascular exam of other limb = normal

Question 19

signs of acute limb ischemia from thrombosis

Answer 19

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.

Question 20

signs of chronic limb ischemia

Answer 20

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).

Question 21

signs of PVD

Answer 21

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

Question 22

PVD Hx

Answer 22

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

Question 23

Ix for PVD

Answer 23

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

Question 24

ABPI for PVD

Answer 24

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.

Question 25

imaging for PVD

Answer 25

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