Incidence of chronic limb ischaemia?
5% of males >50 yrs have intermittent claudication
Definition of chronic limb ischaemia?
Causes of chronic limb ischaemia?
Atherosclerosis
Atherosclerosis summary - pathophysiology?
Difference between Arteriosclerosis and atherosclerosis?
Arteriosclerosis = general arterial hardening Atherosclerosis = Arterial hardening specifically due to atheroma
Atheroma pathology?
Fibrous cap: SM cells, lymphocytes, collagen
Necrotic centre: Cell debris, cholesterol, Ca, foam cells.
Risk factors for chronic limb ischaemia?
Modifiable: Smoking, BP, DM control, hyperlipidaemia, decreased exercise.
Non-modifiable: FH and PMH, Male, increased age, genetic.
Associates vascular diseases with chronic limb ischaemia?
IHD: 90% Carotid stenosis: 15% AAA. Renovascular disease. DM microvascular disease.
Presentation of chronic limb ischaemia?
Intermittent claudication
What is the presentation of critical limb ischaemia?
Fontaine 3-4
1 or more of: Rest pain - Especially @ night - >2 weeks - Usually felt in the foot - Not helped by analgesia - Pt hangs foot out of bed - Due to decreased CO and loss of gravity help.
Ulceration
Gangrene
What is Leriche’ syndrome?
Leriche’s syndrome: aortoiliac occlusive disease
Presents with triad
What is Buerger’s Disease?
Thomboangiitis Obliterans
Signs of chronic limb ischaemia?
Pulses: Pulse and increased CRT (normall <2sec)
- Ulcers: painful, punched out, on pressure points.
- Nail dystrophy/onycholysis.
- Skin:cold, white, atrophy, absent hair.
- Venous guttering (veins collapse)
- Muscle atrophy
Decreased Buerger’s Angle
- >90: normal
- 20-30: ischaemia
- <20: Severe ischaemia.
+ve Buerger’s Sign - Reactive hyperaemia due to accumulation of deoxygenated blood in dilated capillaries.
What is Buerger’s test?
Patient is positioned supine.
Standing at bottom of bed, raise both of the patient’s feet to 45 degrees for 2-3mins.
- Look for pallor - Note at what angle this occurs. If less than 20 degrees indicates severe limb ischaemia.
Then drop leg over side.
- Look for reactive hyperaemia.
Clinical classification? - Fontaine?
What is the rutherford classification?
Mild claudication Moderate claudication Severe claudication Ischaemic rest pain Minor tissue loss Major tissue loss.
What are the investigations for chronic limb ischaemia?
Doppler Waveforms
What if ABPI is high? >1.4
Calcification: CRF, DM
>1.4 . Diabetes leading to high ABPI. Neuropathic and duplex shows its normal.
Can use toe pressure <30mmHg.
What is normal ABPI?
> or equal to 1.
What is asymptomatic ABPI?
Fontaine 1: 0.8-0.9
What is claudication ABPI?
Fontaine 2: 0.6-0.8
What is rest pain ABPI?
Fontaine 3: 0.3-0.6
What is ulceration and gangrene ABPI?
Fontaine 4 <0.3.
Walk Test
Walk on treadmill @ certain speed and incline to establish max claudication distance.
ABPI measured before and after: 20% decreased is significant