Arterial occlusive disease

Question 1

What is peripheral arterial disease

Answer 1

narrowing or occlusion of peripheral arteries, affecting the blood supply to lower limbs

Question 2

What can chronic limb ischaemia present as

Answer 2

Intermittent claudication
Cirtical limb ischaemia
Chronic limb-threatening ischaemia

Question 3

What is acute limb ischaemia

Answer 3

– sudden decrease in arterial limb perfusion, due to thrombotic or embolic causes

Question 4

What is intermittent claudication

Answer 4

diminished circulation leads to pain in the lower limb on walking or exercise that is relieved by rest (‘angina’ of limbs’)

Question 5

What. is critical limb ischaemia

Answer 5

where circulation is so severely impaired that there is an imminent risk of limb loss

Question 6

What is chronic limb-threatening ischaemia

Answer 6

represents end stage peripheral arterial disease where there is threatened limb viability relayed to several factors

Question 7

What is atherosclerosis

Answer 7

Deposition of fatty plaques and thickening of walls in medium to large sized arteries

Question 8

Process of atherosclerosis

Answer 8

1) Endothelial dysfunction
2) Causes inflammation of artery wall and platelet adhesion to wall
3) Inflammation leads to recruitment of mediating cells
4) Macrophages ingest cholesterol which form foam cells
5) Foam cells then form fatty streak
6) Leads to atheroma plaque formation
7) These atheroma have lipid cores and fibrous caps
8) Over time, weakening of fibrous cap
9) Plaque rupture
10) Thrombus formation

Question 9

Common sites of atherosclerosis

Answer 9

Where vessels branch, curve or are irregular and where blood undergoes sudden changes in velocity and direction of flow

1) Circle of WIllis
2) Carotid arteries
3) Popliteal arteries
4) Coronary arteries
5) Abdominal aorta

bruce Willis Catches a Perceptive Criminal named hAns

Question 10

Resulting pathology of atherosclerosis

Answer 10

Weakening of vessel wall- arterial aneurysm or dissection

Demand-supply mismatch- coronary heart disease, peripheral arterial disease, vascular dementia

Thrombosis- Acute coronary syndromes, acute ischaemic stroke, acute limb ischaemia

Atherosclerosis of renal artery can lead to renovascular hypertension

Question 11

Risk factors for atherosclerosis and chronic peripheral arterial disease

Answer 11

Obesity 
Physical inactivity 
Hypertension
Smoking
Hypercholesterolaemia 
Diabetes mellitus 
Old age

Question 12

Clinical signs of atherosclerosis

Answer 12

Xanthelasma
Bruits (carotid or abdo)
Aortic aneurysm on palpation
Poor peripheral pulses

Question 13

What is chronic peripheral arterial disease associated with

Answer 13

Coronary heart disease
Cerebrovascular disease
Diabetes

Question 14

Causes of chronic peripheral arterial disease

Answer 14

Atherosclerosis (most common cause)

Vasculitis (inflammation of vessel or artery)

Fibromuscular dysplasia

Question 15

Why does intermittent claudication lead to pain

Answer 15

Reduced blood flow to limbs

At rest, perfusion is adequate to meet O2 demands of the tissue

During exercise, perfusion is not adequate enough to meet increased O2 demands of the tissue

Question 16

Classical features of intermittent claudication

Answer 16

Gripping, tight, cramp-like pain (typically in calves)

Induced by exercise

Typically relieved by rest

Predominates in one leg usually

Reproducible

Question 17

Difference in presentations between arterial insufficiency and cauda equina

Answer 17

arterial insufficiency- Fixed claudication distance
Pain exacerbated by walking uphill, better downhill
Pain disappears after 1-2 mins of rest typically
Examination findings: Absent peripheral pulses and reduced ABPI but no evidence of neurological findings

Cauda equina
Variable claudication distance
Pain often better when walking uphill but worse downhill
Pain disappears after 15-30 mins typically
Examination findings: LMN findings such as reduced reflexes but pulses present as normal

Question 18

What is the progression of symptoms of peripheral arterial disease

Answer 18

Intermittent claudication

• Claudication distance reducing
• Ischaemic rest pain (worse at night because of reduced nocturnal BP dye to reduced CO and loss of gravity)–> Patients may report improvement of symptoms with legs hanging out of bed or sleeping in chair
• Gangrene

Question 19

Clinical signs of pts with peripheral arterial disease

Answer 19

Pale, cold hairless legs

• Reduced CRT
• Arterial ulcerations (deep, punched out, painful, small, present over toe joints, heel and lateral aspect of leg)

Arterial bruits

Weak of absent pulses

Question 20

two main symptoms of critical limb ischaemia

Answer 20

Rest pain due to insufficient blood supply (burning pain)

Tissue loss- Development of necrotic tissue which if infected becomes gangrene

–>Can lead to osteomyelitis so urgent treatment required

Question 21

Bedside Investigations for peripheral arterial disease

Answer 21

Obs

ECG

Question 22

Blood investigations for peripheral arterial disease

Answer 22

FBCs
ESR (erythrocyte sedimentation rate)- secondary causes such as vasculitis
Thrombophilia screen 
Lipid levels 
Blood glucose

Question 23

Scans for peripheral arterial disease

Answer 23

ABPI (ankle brachial pressure index)

Non invasive- Duplex USS (to determine the site of the disease and indicate the degree of stenosis and length of occlusion)

Non invasive- MRI/CT angiography (prior to revascularisation via angioplasty or reconstructive surgery)

Question 24

What is ABPI (ankle brachial pressure Index)

Answer 24

Method of quantifying severity of arterial disease in legs

Uses a dopplerto measure the blood pressure in the brachial artery and the two arteries in the foot

As arterial disease progresses in the legs, we get reduced flow through the arteries and hence the blood pressure falls

This is commonly measured in patients with ulcers to help differentiate the type of ulcer

Question 25

What is a normal ABPI

Answer 25

1-1.2

Question 26

Conservative management of PAD

Answer 26

Peripheral vasodilators
Smoking cessation
Lipid modification and initiation of statin therapy
Antiplatelet therapy
Optimal management of co-morbidities (HTN, T2DM)

Question 27

Difference between acute limb ischaemia with thrombotic vs embolic causes

Answer 27

Embolic - acute onset. Limb appears white and other leg usually normal. Very severe

thrombotic - Onset more gradual. Leg may not be white and symptoms may be less severe. Presentation is usually with worsening claudication and rest pain.Pulses in other leg may be absent.

Question 28

Risk factors for acute limb ischaemia between thrombotic and embolic

Answer 28

Embolic- 
AFEndocarditis
Mitral stenosis
Aneurysms
Atherosclerotic disease
Presence of graft

Thrombotic-Peripheral vascular disease
Ischaemic heart disease
Cardiovascular disease
Presence of graft
Blood disorders

Question 29

Classical features of acute limb ischaemia

irreversible limb ischaemia?

Answer 29

6P’s
Pain — constantly present and persistent.
Pulseless — ankle pulses are always absent.
Pallor (or cyanosis or mottling).
Power loss or paralysis due to nerve ischaemia
Paraesthesia or reduced sensation or numbness.
Perishing with cold.

irreversible- hard woody muscles and mottled non-blanching appearance. Urgent amputation required

Question 30

Differentials for acute limb ischaemia

Answer 30

Chronic peripheral neuropathy (e.g. diabetic neuropathy. However with this, pulses are present and temperature is normal)

Compartment syndrome (muscles are tense. Not main symptom in acute limb ischaemia)

DVT (red hot swollen calf and pulses normally palpable )

Question 31

Management of acute limb ischaemia

Answer 31

Surgical emergence

If embolus- surgical embolectomy or intra-arterial thrombolysis

If thrombus- angioplasty, bypass or intra-arterial thrombolysis

Question 32

Complications of acute limb ischaemia

Answer 32

Compartment syndrome — reperfusion of ischaemic muscles can cause oedema and increased compartmental pressure.

Reperfusion injury — products of cell death (for examplepotassium, phosphate and myoglobin) are released when blood flow to the ischaemic limb is restored. This can result in rhabdomyolysis, cardiac dysrhythmia, acute kidney injury, multiorgan failure, and disseminated intravascular coagulation.

If untreated- significant necrosis and probably amputation

Question 33

What are vasospastic disorders

Answer 33

Atherosclerosis induces increased contraction of the smooth muscle resulting in greater vasospasm

–> In atherosclerosis it does not stimulate as much prostacyclin and NO to induce relaxation on smooth muscle cells. There is not as much inhibition of aggregation of platelets. Greater aggregation of platelets produce ASP, serotonin and thromboxane 2 which cause contraction of smooth muscle

Question 34

What are the main vasospastic disorders

Answer 34

Raynaud’s syndrome
Acrocyanosis
Livedo reticularis

Question 35

What is Raynaud’s disease

Answer 35

Charecterised by paroxysmal vasospastic and subsequent vasodilatory chain of events affecting small peripheral arterioles

Usually affects hands and feet. Precipitated by cold and emotion

Colour change of digits

• Pale- ischaemia
• Blue- cyanosis
• Red- hyperaemia

Question 36

Raynaud’s disease vs phenomenon

Answer 36

Raynaud’s disease more likely to be primary - Such as present in younger, female patients with a genetic component with no features of underlying disease

Phenomenon is secondary. More likely to present as an older patient, with more severe symptoms (digital scars, ulceration or gangrene and nail changes)

Question 37

Secondary causes of Raynaud’s

Answer 37

autoimmune- Scleroderma, rheumatoid arthritis

Environment- smoking, trauma, chronic vibration, chemical exposure

Endocrine- diabetes, hypothyroidism

Arterial- Buerger’s disease

Blood- lymphoma, polycythaemia

Drugs - B blockers, COC, cytotoxic agents