Arterial Occlusive Disease

Question 1

What are the crural vessels?

Answer 1

three vessels that run below knee
Posterior Tibial Artery
Anterior Tibial Artery
Peroneal Artery

Question 2

Meaning of ischaemia?

Answer 2

lack of oxygenated blood supply to part of the body- leading to anaerobic respiration

Question 3

Meaning of thrombus?

Answer 3

blood clot that forms in situ ( for e.g. at site of plaque rupture)

Question 4

Meaning of embolus?

Answer 4

blood clot that travels to a different site (distal)

Question 5

meaning of atherosclerosis?

Answer 5

build up of plaque (atheroma) inside arteries
described as narrow and hardening of blood vessels

Question 6

What does peripheral arterial disease refer to?

Answer 6

arteries only

Question 7

What does peripheral vascular disease relate to?

Answer 7

describes any circulatory disorders- including venous and lymphatic systems

Question 8

Likely diagnosis for worsening pain in left leg on exertion, smoker and hypertension?

Answer 8

intermittent claudication

Question 9

Pathophysiology of intermittent claudication?

Answer 9

atherosclerosis causes areas within arteries (supplying the legs) to become narrowed over time.
narrowed arteries cannot supply blood quickly enough when demand is high and this leads to anaerobic respiration and release of painful metabolites.

Question 10

What diseases could corelate with patients describing cramping pain in one or both calves?

Answer 10

corelates with disease in UPSTREAM blood vessels
for e.g. femoral or popliteal arteries

Question 11

What diseases could corelate with patients describing cramp in buttocks, thighs and erectile dysfunction?

Answer 11

distal aorta or iliac arteries affected

Question 12

Differential diagnosis for exertional leg pain?

Answer 12

osteoarthritis - pain comes on after variable amount of exercise

neurogenic (impingement of nerves exiting spinal foramen) - relived by bending over

venous- patients with history of proximal DVT (deep vein thrombosis) can suffer from pain in leg or legs due to impaired venous return but relived by elevation of leg

Question 13

Risk factors for PAD? Peripheral arterial disease

Answer 13

smoking
hypertension
diabetes
and dislipodaemia

Question 14

Examination for PAD?

Answer 14

lose hair from legs and feet
shiny skin appearance
slow growing and brittle toenails
cooler and paler skin

Question 15

What would we feel for in PAD?

Answer 15

Examine for presence or absence of peripheral pulses i.e femoral, politeal , posterior tibial and dorsalis pedis (comparing sides)

Question 16

Results from using a hand held doppler?

Answer 16

Normal = triphasic waveform (systole, diastole, recoil)
ie: three sounds

Abnormal = biphasic or monophasic waveform (loss of recoil)
ie: two sounds or single ‘woosh’
or absent

Question 17

Where are primary areas to check blood flow in peripheral arteries?

Answer 17

Dorsalis Pedis Artery (DPA): Located on the top of the foot.
Posterior Tibial Artery (PTA): Found behind the ankle, slightly to the inside of the Achilles tendon. These are primary areas to check for blood flow in the lower extremities.

Question 18

What does ankle brachial pressure index involve?

Answer 18

measuring systolic blood pressure in arm and leg and dividing one by the other

Question 19

What do ABPI results mean?

Answer 19

normal ABPI- between 0.8-1.3

ABPI less than 0.5- indicates severe arterial disease

ABPI > 1.3- reflects arterial calcification

Question 20

Management of intermittent claudication?

Answer 20

secondary prevention

Modify risk factors and manage cardiovascular risk
1. Medications (antiplatelet, statin)
2. Smoking cessation*
3. BP control*
4. Good glycaemic control*

exercise
Improve collateral circulation  improve pain-free walking distance

• Self-directed: can encourage to record daily step count/measurable distance ie: number of lampposts
• Supervised – not available in all areas

Question 21

Pathophysiology of critical limb threatening ischaemia?

Answer 21

progressive atherosclerosis causes severe narrowing or complete occlusion in arteries
even without gravity, supply cannot match demand even at rest
anaerobic metabolites releases- leads to pain
Patients keep leg(s) hanging down -oedema - skin breakdown/ulceration which doesn’t heal

Question 22

Symptoms of critical limb threatening ischaemia?

Answer 22

rest pain and/ or tissue loss

Question 23

Describe buergers test?

Answer 23

Another test to assess peripheral blood supply

1. Elevate leg >45 degrees and hold
   - in critical limb threating ischaemia have feet becoming pale and see veins empty (venous guttering)
2. Patient sits with leg dependant (legs dangling over bed)
   -foot appears red (sunset foot)

Question 24

Initial management of CLTI?

Answer 24

Full blood count (FBC)
Urea and electrolytes (U&Es)
Coagulation
G&S (incase blood transfusion required)

ECG

Antiplatelet, statin
Analgesia- relief of pain
DVT prophylaxis - prevention of DVT
+/- Antibiotics- infection in ulcer

CT angiogram of lower limbs

ECHO and pulmoanry function tests

Question 25

Why should patients with peripheral arterial disease never have TEDS? (Compression stockings)

Answer 25

could further compromise the peripheral blood supply instead should have a small dose of an injectable blood thinner

Question 26

Decision making factors in vascular surgery?

Answer 26

Pattern of disease - symptoms - imaging Complexity - previous surgeries - operative plan Conduit - vein vs prosthetic - quality, length Operative risk - co-morbidities - tests of fitness - frailty - previous level of function - anaesthetic risks - recovery Patient wishes - shared decision making

Question 27

Different types of operative management?

Answer 27

conservative/ palliative-Symptom management endovascular intervention -Angioplasty +/- stent open surgery -Endarterectomy Bypass Amputation* hybrid procedure-eg: endarterectomy and stent

Question 28

When might amputation be required?

Answer 28

Amputation may be required if there is no revascularisation option, or if this is not successful

Question 29

Describe endovascular interventions?

Answer 29

use wires and balloons to open up narrowed blood vessels-angioplasty - Stent can then be deployed to reduce risk of re-stenosis Best outcomes for focal lesions Can be day case under local anaesthetic

Question 30

Disadvantages of endovascular interventions?

Answer 30

Potential to make blood supply worse – dissection, distal embolisation etc - Longevity of any improvement variable - Caution in patients with poor renal function

Question 31

What are the different operations involving open arterial surgery?

Answer 31

bypass -additional channel for blood to flow endarterectomy- clearing out plaque from inside of blood vessel. Clamp vessels above and below

Question 32

Names of bypass operations?

Answer 32

fem-pop bypass: go from either common femoral or superficial femoral artery to the popliteal artery ax-fem or ax-bifem will gofrom axillary artery to one or both femoral arteries

Question 33

What is a conduit?

Answer 33

carries the blood for bypass either vein (preferred) or prosthetic tube

Question 34

Why is a vein a preferred conduit?

Answer 34

better long term patency reduced rates of infection

Question 35

Challenges of open surgery?

Answer 35

significant blood loss, risk of major amputation or death long hospital stay and post operative recovery

Question 36

Likely diagnosis for " painful,cold,pale right arm , unable to move fingers, can't feel pulses. Was on warfarin for AF but was stopped"

Answer 36

acute limb aschaemia

Question 37

What are the 6 P's of acute limb ischaemia?

Answer 37

(also present in CLTI) pain pallor pulseless perishingly cold (late signs) paraesthesia paralysis

Question 38

Pathophysiology of acute limb ischaemia?

Answer 38

Sudden blockage to blood flow in a normal artery leads to ischaemia leads to cell death (necrosis)

Question 39

Clinical appearance of acute limb ischaemia?

Answer 39

Acute arterial spasm - pallor Deoxygenated blood fills skin - mottling Stagnant blood coagulated - fixed staining (irreversible ischaemia)

Question 40

What will an attempt to revascularise the limb lead to?

Answer 40

release lots of metabolites (potassium, myoglobin and hydrogen ions) into systemic circulation and leading to acidosis , acute kidney injury, cardiac instability and potentially death

Question 41

What does tenderness of muscle on palpation signal?

Answer 41

indicates the limb is threatened

Question 42

Acute vs acute-on -chronic limb ischaemia?

Answer 42

similarities -sudden change in symptoms disimilarities -acute limb ischaemia changes happen quicker. on chronic have developed alternative routes for blood flow. -common aetiology of on chronic limb ischaemia is thrombosis in situ as a result of atherosclerotic plaque rupture. Also occur if there is an intervention to improve blood supply (such as stent, bypass graft) - which then blocks -in contrast, acute limb ischaemia usually occurs as a result of embolus- which lodges as a place where blood vessels divide (left atrium with conditions that cause turbulent blood flow) Non cardiac causes include coagulation disorders and malignancy (predisposition to clot formation).

Question 43

Initial management of ALI?

Answer 43

start an intravenous blood thinner- heparin (reduces propagation of the clot) blood tests Full blood count (FBC) Urea and electrolytes (U&Es) Coagulopathy screen( if unsure of precipitating factor)- before anticoagulants G&S (for blood transfusion) ECG (24 hour tape) ECHO (to look for clots in heart) CT angiogram to confirm diagnosis and help plan the intervention

Question 44

What is the most common operation for acute limb ischaemia and give features?

Answer 44

embolectomy can do under general anaesthetic, regional block or even local anaesthetic make a cut above and below the clot (control with clamps) make small opening in front wall of the artery- which allows us to pass a small plastic tube called a Fogarty catheter up beyond the clot at the end there is a small balloon which can pull clot through hole made.

Question 45

Post embolectomy actions?

Answer 45

If unsuccessful - amputation or palliation Consider need for fasciotomies Anticoagulation Further investigations for underlying cause if not already known

Question 46

What is compartment syndrome?

Answer 46

increased pressure within a closed osteofascial compartment, resulting in impaired local circulation. Without prompt treatment, acute compartment syndrome can lead to ischemia and eventually, necrosis.

Question 47

What is an endarterectomy?

Answer 47

surgical operations to clear out the atherosclerotic plaque from the inside of an artery

Question 48

Which patients would be considered for a carotid endarterectomy?

Answer 48

- symptomatic carotid stenosis - >50% ICA stenosis on US - good neurological recovery - within 2 weeks from event

Question 49

why is CEA not offered to patients with ongoing and profound neurological impairment ?

Answer 49

To reduce the risk of further neurological impairment from an embolic carotid plaque Studies show future stroke risk reduction greater than with medical management alone However, CEA will not improve current neurology (symptoms)

Question 50

Risks of carotid endarterecetomy?

Answer 50

stroke around time of operation damage to other structures (numbness along jaw line, facial droop, tongue deviation, changes to voice

Question 51

How does blood get to the brain during carotid endarterectomy?

Answer 51

Brain perfusion reliant on complete Circle of Willis, with supply from contralateral carotid artery and vertebral arteries OR shunt can be used