Peripheral Vascular Disease

Question 1

Definition

Answer 1

Essentially IHD of lower limb arteries
- Intermittent Claudication of vessels
- Major circulating disorder characterised by atrial obstruction leading to reduced blood supply + ischeamia in lower limbs

Question 2

Epidemiology

Answer 2

Prevalence increases with age
40 +
Male

Question 3

Risk factors

Answer 3

Smoking
Obesity
CKD
Diabetes
Hypertension
Sedentary lifestyle
Hyperlipidemia

Question 4

Pathophysiology

Answer 4

Acute to Acute on Chronic
Intermittent Claudication of vessels = essentially a partial blockage of the leg or peripheral vessels by an atherosclerotic plaque +/or thrombus = pain on exertion
-> insufficient perfusion of lower limb
When muscle receives less O2 = ISCHAEMIC = cells release adenosine = affects nearby nerves causing pain = lactic acid production which may also contribute to pain

Question 5

Aetiology

Answer 5

Atherosclerosis
Vasospasm of vessels
Aortic coarctation
Temporal arteries
Burgers disease

Question 6

CRITICAL LIMB ISCHAEMIA DEFINITION

Answer 6

= Occlusion is v.big, blood supply below adequate to meet metabolic demand. Pain at rest + risk of gangrene/infection = chronic

Question 7

ACUTE LIMB ISCHAEMIA

Answer 7

COMPLICATION
Commonly caused by emboli, usually of cardiac origin = sudden disease in limb perfusion. Emboli tend to lodge at artery bifurcations or in vessels abruptly narrow =
Total occlusion of vessel at site of critical limb ischeamia lesion

Question 8

6 P’s (critical limb ischaemia)

Answer 8

Pulselessness
Pallor
Pain
Perishingly cold
Paralysis
Paraesthesia
- present in chronic limb ischeamia too. BUT the more you have, the more limb threatening (All 6 = deadly! EMERGENCY)

Question 9

What happens when blood vessel supplying region is occluded?

Answer 9

1. Irreversible nerve damage (within 6hrs)
2. Irreversible muscle damage (6-10ths)
3. Skin changes last to appear therefore likely gangrenous

Question 10

Symptoms

Answer 10

Cramping pain after walking for a given distance (Claudication distance) + relieved by rest
- Calf Claudication = superficial femoral disease
- Buttock Claudication = common iliac
- Thigh Claudication = common femoral
- Aortoilliac = Leriche syndrome
Ulceration
Gangrene
Foot pain at rest - burning pain at night relieved by hanging legs over side of bed

Question 11

Signs

Answer 11

Absent femoral, popliteal, or foot pulses
Cold
White
Atrophic skin
Punched out ulcers (often painful)
Postural dependant colour changes
BEUGERS ANGLE - Leg goes pail when raised off couch > 20 degrees + capillary filling times > 15 s are found in severe ischeamia

Question 12

Diagnosis

Answer 12

FIRST LINE = Ankle Brachial Pressure Index (ABPI)
> 1.4 = abnormally calcified vessels, false negative often due to diabetes
0.9 - 1.2 = normal
0.5 - 0.9 = intermittent claudication (mild to moderate PAD)
< 0.5 = rest pain, ulceration, gangrene (critical limb ischemia)
Absence of pulse in the lower extremity on Doppler USS, ABPI cannot be calculated = suspect acute limb ischeamia
GOLD STANDARD = CT ANGIOGRAM - But much more invasive
Doppler USS - degree of stenosis
ECG + U+E + FBC

Question 13

Fontaine Classification (stages 1-4)

Answer 13

1. Asymptomatic
2. Intermittent claudication
   a. Claudication after walking >200m
   b. Claudication after walking <200m
3. Chronic limb ischemia = rest pain
4. Ischaemic ulceration or tissue loss (gangrene)

Question 14

Treatment

Answer 14

Intermittent claudication
- RF management (smoking cessation, decrease in BMI, BP control (ACE-I), Statins, Anti-platelet (aspirin, clopidogrel), T2DM + anticoagulation (heparin))
Chronic limb ischeamia
- Revascularisation surgery (PCI if small, bypass if longer) - Amputation if severe
Acute limb ischeamia
- SURGICAL EMERGANCY -> REVASCULARISATION WITHIN 4-6 HOURS OTHERWISE AMPUTATION RISK INCREASES

Question 15

Complication

Answer 15

Amputation,
Permanent limb weakness,
Rhabdomyolysis (Ca2+ increase + K+ released into blood -AKI -Arrhythmias)
Increase risk of cerebrovascular accidents + CVD