L16: Peripheral arterial and venous disease

Question 1

What are the different classification of veins in the lower leg?

Answer 1

Superficial–> subcutaneous tissue

Deep–> underneath deep fascia (with major arteries)

Question 2

What connects the superficial and deep veins?

Answer 2

Perforating veins

Question 3

What are the superficial veins of the leg?

Answer 3

Long (great) saphenous vein–> formed from dorsal venous arch, up medial side of the leg, anterior to medial malleolous at ankle into the femoral vein under inguinal ligament –> external iliac
Short (small) saphenous vein–>formed form the dorsal venous arch of the foot, passes posteriorly to the lateral malleolous between two heads of gastrocnemius into the popliteal vein –> femoral vein–> external iliac

Question 4

What are the deep veins of the leg?

Answer 4

Anterior tibial vein–> some branches from dorsal venous arch
Posterior tibial vein and peroneal (fibular) vein–> posterior tibial vein enters posterior to medial malleolous
Posterior surface of knee all 3 untie to form popliteal vein –> femoral vein –> external iliac
Profunda femoris vein–> drains muscles of thigh –> femoral vein –> external iliac

Question 5

Describe what the calf muscle pump is?

Answer 5

The ‘Peripheral heart’
Gravity makes blood return difficult
Calf muscle contraction–> squeezes blood from superficial to deep via perforating veins
Valves open–> blood enters deep veins–> valves close prevent retrograde movement
Soleus and gastrocnemius important ones
Venous pressure in foot reduced during exercise

Question 6

What are some common peripheral venous diseases?

Answer 6

Varicose veins
Venous eczema and ulceration
Venous hypertension
Thrombosis (DVT specifically)

Question 7

What are varicose veins?

Answer 7

Valves ineffective and blood movement is slow or even reversed
Walls of veins weaken–> varicosities develop and valve cusps separate becoming incompetent
Veins tend to be tortuous, twisted
Form bumps under the skin
Usually asymptomatic
Usually saphenous veins

Question 8

What pathologies can develop as a result of varicose veins?

Answer 8

1. Pt describe heaviness and aching, muscle cramps, throbbing and itchy skin–> along affected vein
2. Haemorrhage–> usually warm shower, blood pooling in legs, dilates BV–> bleeding along the leg
3. Varicose eczema
4. Superficial vein thrombophlebitis–> thrombus with inflammation–> painful erythematous and increased risk of DVT
5. Chronic venous insufficiency–> reflux or obstruction–> venous hypertension
6. Oedema
7. Haemosiderin staining–> RBC released, oxidised by macrophages, Fe2+–> Fe3+, rusting appearance on skin
8. Lipodermatosclerosis (inflammation and thickening of fat layer under the skin)
9. Venous ulceration

Question 9

What happens during venous eczema?

Answer 9

Chronic, itchy red and swollen tight skin

Lipodermatosclerosis can develop–> hard to touch (hardening of fatty tissue)

Question 10

What happens during ulceration?

Answer 10

Chronic painful exposed skin
Often develop around hard nodular areas e.g. medial malleolous–> result of venous hypertension
Difficult to treat
Developement of chronic venous insufficiency occurs in 50% DVT patients

Question 11

Why does the calf muscle pump fail? Who is at risk of calf muscle failure?

Answer 11

Plantar flexion of the foot required
Deep veins can be incompetent—> valve failure, blockages—> retrograde flow—> overwhelmed
Superficial vein incompetence—> blood from deep —> superficial —> calf muscle pump overflows
Immobility, obesity, elderly, people with Parkinson’s disease (shuffle- don’t walk properly) —> at risk

Question 12

How is calf muscle failure treated?

Answer 12

Ligation (tie veins to stop them bulging) and vein stripping (removal of vein)

Question 13

What are the difference between arterial and venous thrombosis?

Answer 13

Arterial—> platelet rich - activated endothelium- aggregate- plug hole —> most common cause atheroma

Venous —> fibrin rich, little platelet—> caused by stasis of blood- little flow coagulation of blood
- Stasis with an additional factor—> trauma, COCP, dehydration…

Question 14

What is Virchow’s triad? How does it lead to thrombus formation?

Answer 14

1. Blood flow
2. Vessel wall
3. Blood components
   Change in one (usually two) of these leads to thrombus formation

Question 15

What is a deep vein thrombosis (DVT)?

Answer 15

Clotting of blood in a deep vein
Usually calf

Due to impaired venous return and hypercoaguability

Can develop into pulmonary embolism—> (fatal) consequence

Question 16

What are the signs of DVT?

Answer 16

Vary in severity and frequency
Usually asymmetric
Calf tendernesss, warmth, distended and visible superficial veins, oedema
Pyrexia (raised body temp) with no other cause

Question 17

What are some other causes for DVT formation?

Answer 17

Soft tissue trauma
Cellulitis
Lymphatic obstruction

Question 18

How is DVT diagnosed?

Answer 18

Wells’ score
Pre test probability —> how likely you are to develop DVT
Signs and symptoms

Question 19

What are some of the risk factors for DVT?

Answer 19

Stasis—> before and after surgery, long haul flights etc
Trauma—> prothrombotic state
Malignant
Pregnancy —> hypercoaguable blood

Question 20

How is DVT avoided?

Answer 20

Promote mobility soon after surgery

Prophylaxis —> anticoagulants —> given before surgery

Question 21

How is physiology designed to limit actue ischaemia?

Answer 21

Collateral circulation

Alternative routes to the same destination

Question 22

How does the body adapt to deal with stenosis of vessels over a period of time?

Answer 22

Build collateral vessels over period of time

Question 23

What happens during acute limb ischaemia?

Answer 23

Occlusion of vessels occurs acutely–> minutes to days
No collateral circulation develops
Blood supply to area distal to occlusion cut off
6P’s of ischaemia
Refer to vascular surgical unit
Assess extent of threat of limb–> angioplasty, thrombectomy, intra-arterial thrombolysis or amputation

Question 24

What are the 6P’s for the symptoms of ischaemia?

Answer 24

Pain --> initially 
Pallor
Paraesthesia --> tingling or numbness
Paralysis 
Pulseless
Perishing with cold --> no perfusion

Question 25

What is chronic peripheral arterial disease?

Answer 25

Intermittent claudication of the lower limb (cramping pain induced by exercise)
Partially occluded BV –> atherosclerosis –> muscle can’t get blood supply

Question 26

How is chronic peripheral arterial disease managed?

Answer 26

Exercise--> develop collateral vessels 
Smoking cessation 
Antiplatelet drugs
Angioplasty
Bypass graft

Question 27

What is critical ischameia? What happens if it is untreated?

Answer 27

Rest pain–> pain at rest
Eased by hanging foot out of bed etc… gravity last attempt at getting blood to limb
Leads to ulceration and gangrene–> viability of limb severely compromised

Question 28

What is the pathology of claudication?

Answer 28

Atheroma–> atherosclerosis–> claudication
Untreated–> ischaemia when blood supply cut off
Collateral arteries develop to try and deal with it but eventually they become blocked too

Question 29

What pulses can be palpated in a healthy lower limb?

Answer 29

Femoral pulse–> Midinguinal point (mid way between ASIS and pubic symphysis)
Popliteal pulse–> deep in popliteal fossa
Dorsalis pedis pulse–> lateral to extensor hallucis longus tendon
Posterior tibial pulse–> behind the medial mallelous

Question 30

How is blood flow recorded?

Answer 30

Doppler ultrasound

Measures real time flow and velocity

Question 31

How does doppler ultrasound work?

Answer 31

As blood flows sound is produced
If it is moving away from the machine it is lower frequency
If it is moving towards the machine it is higher frequency
Echos from stationary tissue remains the same

Question 32

What index is commonly used to measure the flow in the lower limbs? Where is it measured? How is it calculated?

Answer 32

Ankle-brachial pressure index (ABPI)
Measured in brachial, dorsalis pedis and posterior tibia arteries
Calculated
- divide ankle systolic by brachial systolic

Question 33

What is ABPI used to diagnose?

Answer 33

ABPI < 0.9 indicate peripheral artery disease