Peripheral Vascular Disease

Question 1

What is PVD?

Answer 1

-When peripheral arteries (excluding the coronary or cerebral vessels)
-Are abnormally narrowed or blocked
-Causing reduced blood flow

Question 2

PVD Epidemiology

Answer 2

-70+ more females/ 1 in 6 have PVD
-Increasing age= increasing prevalence
-Common

Question 3

Pathogenesis of atherosclerosis

Answer 3

-Fatty streaks accumulate under innermost subendothelial layer
=Inflammatory response
=Smoking and hypertension aggravate plaque

1. Quiescent disease= artery heals and calcification replaces organic materials in wall, arteries left narrow
2. Active disease= ruptured plaque, aggressive thrombosis- narrows blood vessel/ occlude (thrombosis in situ)
   =new fibrous plaque leads to narrowing
   =Necrotic core and thickened fibrous plaque which is dense in calcium

Question 4

PVD risk factors

Answer 4

-Smoking
-Advancing age
-High cholesterol
-Obesity
-DM
-CKD

Question 5

Describe the process of collateralisation

Answer 5

-Narrow artery= less blood flow
-Tissue artery is supplying becomes starved of blood
=Release growth factors to stimulate angiogenesis (physiological response to hypoxia)
=Compensatory mechanism to maintain end organ perfusion
=Smaller, more tortuous as natural bypass

Question 6

What is involved in the clinical assessment of PVD?

Answer 6

-How severe is the ischaemia?
-Where is the obstructive lesion?
-How fit is the patient?
=Blood tests
=Radiology

Question 7

Signs of critical limb ischaemia

Answer 7

-Intermittent claudication (100m exercise threshold)
-Sunset Red foot: Buerger’s Test to differentiate from cellulitis (hypoxic- vasodilation)
-Rest pain relieved by hanging foot, out of bed at night (gravity)
-Tissue loss- gangrene or ulcers
-Infection/ pus

Question 8

What is the Ankle Brachial Pressure Index?

Answer 8

ABPI= Ankle pressure (pressure at which pedal doppler signal appears)/ brachial pressure= determines severity

> 12= uncompressible vessels
1.2-0.9= normal
0.8-0.6= moderate PVD
<0.5= severe PVD (critical limb ischaemia)

-Can be raised in calcified vessels as cannot be compressed so very severe

Question 9

What arteries are in the aorto-iliac segment?

Answer 9

-Aorta
-Common iliac artery
-External iliac artery (leg)
-Internal iliac artery (pelvis)

Question 10

What arteries are in the femoro-popliteal segment?

Answer 10

-Common femoral artery (previously external iliac at groin)
-Profunda femoris artery
-Superficial femoral artery
-Popliteal

Question 11

What arteries are in the crural segment?

Answer 11

-Anterior tibial
-Posterior tibial
-Peroneal (to ankle)

Question 12

Findings of aorto-iliac segment disease

Answer 12

-Aortic heard
-Dimished/absent femoral, popliteal, dorsalis pedis (dorsum between 1st and 2nd metatarsals) and posterior tibial pulse (behind medial malleolus)

Question 13

Findings of femoro-popliteal segment disease

Answer 13

-Cannot hear popliteal, dorsalis pedis and posterior tibial pulse

Question 14

Arterial imaging for PVD

Answer 14

-Arterial Duplex/ doppler ultrasound (arterial tree, blood flow through vessel; velocity increases in stenosis but volume of blood decreases)
-CT angiogram (radiation and contrast agents- calcification)
-MR angiogram (smaller arteries, crural)
-Digital subtraction angiography

Question 15

Medical therapy for PVD

Answer 15

-Stop smoking
-Antiplatelet agent (aspirin or clopidogrel)
-Statin
-Blood pressure control
-DM control
-No calf compression

Question 16

Surgical therapies for PVD

Answer 16

-Endovascular therapy
=Percutaneous balloon angioplasty
=Stent

-Endarterectomy
=Remove atherosclerotic plaque (common femoral artery or carotid artery in stroke patients, with small blockage)

-Bypass surgery
=Anatomical: aorto-femoral bypass (fit patient), femoro-popliteal (saphenous vein or synthetic)
=Extra-anatomical: femoro-femoral bypass, axillofemoral bypass

-Major limb amputation
=below knee: femoro-popliteal or crural segment occlusions
=above knee: aorto-iliac segment occlusions

Question 17

What are arterial ulcers?

Answer 17

-Occur on the toes and heel/ dorsum of foot
-Typically have a ‘deep, punched-out’ appearance
-Painful, worse at night and improved by lowering leg- smaller and deeper than venous ulcers
-There may be areas of gangrene, can be pale due to poor blood supply
-Cold with no palpable pulses
-Low ABPI measurements, associated with PAD

Question 18

Investigation and management of arterial ulcers

Answer 18

-ABPI
-Blood tests= infection and DM, albumin and anaemia

-Surgical revascularisation

Question 19

Presentation of venous leg ulcers

Answer 19

-Features of venous insufficiency: oedema, brown pigmentation, lipodermatosclerosis, eczema
-Location above the ankle, painless, irregular gently sloping border
-Gaiter area (between top of foot and bottom of calf muscle)
-Larger, more superficial than arterial ulcers
-Pain relieved by elevation and worse on lowering leg

Question 20

Investigation of venous ulcers

Answer 20

Doppler ultrasound looks for the presence of reflux and duplex ultrasound looks at the anatomy/ flow of the vein

Question 21

Management of venous ulcers

Answer 21

-4 layer compression banding after exclusion of arterial disease or surgery
-If fail to heal after 12 weeks or >10cm2 skin grafting may be needed

Question 22

Difference between deep and superficial venous insufficiency

Answer 22

Deep venous insufficiency is related to previous DVT and superficial venous insufficiency is associated with varicose veins