Peripheral Vascular Occlusive disease

Question 1

Fontaine Classification for PAD

Answer 1

Stage 1- Asymptomatic
Stage 2- IC
Stage 3- Rest pain
Stage 4- Ulceration/gangrene

Question 2

Sunset foot

Answer 2

Sign of very severe critical limb ischaemia
Poor condition of toe nails
Colour due to small arteriole vasodilation as a response to chronic lactic acidosis built up in the foot

Question 3

What happens when a main artery is slowly stenosed then occlused because of atherosclerosis

Answer 3

Collateral vessels form
Stimulated by multiple episodes of ischemic pain (lactic acidosis)
Ask patients to walk until limit of their pain- encourages formation of these collaterals

Question 4

Commonest cause of foot neuropathy

Answer 4

Diabetes

Question 5

Diabetic neuropathy is also associated with

Answer 5

Fibrosis of the plantar fascia of the foot

Question 6

Fibrosis of the plantar fascia of the foot

Answer 6

Results in the metatarsal heads pushing down into the sole and a hammering of the toes

Question 7

Problems of the concept of critical limb ischaemia in diabetic patients

Answer 7

Rest pain is not a reliable sign in diabetic neuropathy

Severely calcified blood vessels in diabetes can allow for high ankle pressures which can appear falsely reassuring

Question 8

Acutely ischaemic Limb 6 Ps

Answer 8

Pain
Pallor
Perishingly Cold
Pulseless
Paraesthesia
Paralysis

Question 9

Acutely Ischaemic limb

Answer 9

Rest pain for less than 2 weeks requiring analgesia
And/or ulceration
And/or gangrene
Ankle pressure <50mmHg
Toe pressure (in diabetics)<30 mmHg

Question 10

Acute limb ischaemia progression 0-6hrs

Answer 10

Marble white leg
Intense vasospasm of distal arterial tree
Emptying of veins

Question 11

Acute limb ischaemia progression 6-12 hours

Answer 11

Mottled leg
Vasodilation in response to smooth muscle hypoxia
Fills with deoxygenated blood
Still blanches

Question 12

Acute limb ischaemia progression 12 hours +

Answer 12

Irreversible ischaemia
Stagnant blood coagulates and thrombus propagates
Capillary rupture causing fixed staining
Tense muscles
Blistering

Question 13

Acute limb ischaemia Category I

Answer 13

Not immediately threatened
No sensory loss
No muscle weakness
Audible arterial doppler
Audible venous doppler

Question 14

Acute limb ischaemia Category IIa

Answer 14

Salvable if prompt treatment
Minimal sensory loss in toes
No muscle weakness
Inaudible Arterial doppler
Audible venous doppler

Question 15

Acute limb ischaemia category IIb

Answer 15

Salvable if immediate treatment
Moderate sensory loss plus pain
Mild/moderate muscle weakness
Inaudible arterial doppler
Audible venous doppler

Question 16

Acute limb ischaemia category III

Answer 16

Major tissue loss of permanent nerve damage inevitable
Profound or anaesthetic sensory loss
Profound muscle weakness/paralysis
Inaudible arterial doppler
Inaudible venous doppler

Question 17

Causes of acute limb ischaemia

Answer 17

Thrombosis (60%)
Embolism (30%)
Rare

Question 18

Causes of acute limb ischaemia- Thrombosis “Acute on chronic”

Answer 18

60%
Atherosclerosis
Popliteal aneurysm
Graft occlusion
Thrombotic conditions

Question 19

Causes of acute limb ischaemia- Embolism “true acute”

Answer 19

30%
Atrial fibrillation (80%)
Mural thrombosis (thrombus in the wall of a vessel higher up dislodging and travelling distally to block the vessel further downstream)
Vegetations
Proximal aneurysms and plaques

Question 20

Causes of acute limb ischaemia- rare

Answer 20

Trauma

Question 21

Causes of acute limb ischaemia- AF

Answer 21

If the heart is not beating in coordinated fashion, there will be areas where the blood flow is slower than normal. This will lead to stasis of blood and hence clots. These clots can be dislodged from the heart and fly round the circulation causing end organ ischaemia - brain (ischaemic stroke); limbs; visceral ischaemia eg. mesenteric ischaemia.

Question 22

Causes of acute limb ischaemia- vegetations

Answer 22

Infected vegetations (endocarditis) on heart valves can similarly dislodge and embolise into the vasculature

Question 23

Immediate management of Acute limb ischaemia

Answer 23

Blood
ECG
CXR
Echo
Imaging of arterial tree
TREAT

Question 24

Acute ischaemia non-viable limb

Answer 24

Fixed motting (pressing on the purpuric areas) will not cause them to blanche- this signifies the arterioles and end capillaries have ruptured in the effort to open up as much as possible

Question 25

Acutely ischaemic limb- all require

Answer 25

oxygen
IV fluids
Analgesia
IV heparin

Question 26

Ischaemic limb can lead to

Answer 26

Primary Amputation
Angiogram
Embolectomy

Question 27

Embolectomy

Answer 27

Fogarty catheter inserted into artery with thrombus
Inflated Fogarty balloon
Remove thrombus

Question 28

Reperfusion injury

Answer 28

Once you return oxygen to muscle that has been starved of oxygen for more than 4 hours, some degree of reperfusion injury will occur

Question 29

Reperfusion injury causes

Answer 29

Free oxygen radicals
Activation of coagulation
Mitochondrial dysfunction
Myocyte hypercontracture

Question 30

Free oxygen radicals

Answer 30

Alters membrane proteins and phospholipids
Increased oxidative stress
Increased inflammation
Leukocyte activation and aggregation

Question 31

Activation of coagulation

Answer 31

Platelet activation

Compliment activation leading to microvascular and endothelial dysfunction

Question 32

Mitochondrial dysfunction

Answer 32

Decreased mitochondrial calcium concentration

Decreased ATP and apoptosis

Question 33

Myocyte hypercontracture

Answer 33

Increased intracellular calcium

Reoxygenation of myocytes

Question 34

Reperfusion swelling

Answer 34

Reperfusion associated with extensive swelling of the muscles (typically the calf)
The calf muscles are constrained within the fascial envelopes of the leg (there are 4 of these)
If these envelopes are not released with fasciotomies then compartment syndrome will result with rhabdomyolysis and kidney failure