Chronic Limb Ischaemia, Acute Limb Ischaemia, Diabetic Foot Disease, & Varicose Veins (pathology) Flashcards
What is chronic limb ischaemia? (Pathology)
Atherosclerotic disease of arteries supplying lower limb (less commonly vasculitis, Buerger’s disease)
Symptoms lasting greater than 2 weeks
What is critical limb ischaemia?
tissue loss, ulceration
- due to minimal blood flow following years of atherosclerosis
- rest pain/necrosis/gangrene
What are the risk factors for chronic limb ischaemia (6)?
- Male
- Age
- Hypertension
- Hypercholesterolaemia
- Diabetes mellitus
- Obesity
What are the 4 stages of the Fontaine classification of symptoms for chronic limb ischaemia?
- Stage I: asymptomatic, incomplete blood vessel obstruction
- Stage II: mild claudication pain
• Stage IIA: claudication when walking > 200 m
• Stage IIB: claudication when walking < 200 m - Stage III: rest pain, esp. feet
- Stage IV: necrosis &/or gangrene of limb
(Stage III & IV) = critical limb ischaemia
What is claudication? What relieves this pain?
Pain described as dull or cramping - worse at night
- symptoms relieved by hanging legs off the side of the bed
What are the visible signs of chronic limb ischaemia?(5)
- Ulceration
- Pallor
- Hair loss
- Cold legs – Poikilothermia
- Reduced/absent pulses
What are the signs you can feel of chronic limb ischaemia?
Peripheral:
- Temperature
- Capillary refill time
- Peripheral sensation
- Pulses (start at aorta)
What can be auscultated in chronic limb ischaemia?
AUSCULTATE with hand held doppler —> dorsal pedis and posterior tibial
What examinations can be performed to identify chronic limb ischaemia (2)?
1) Ankle Brachial Pressure Index (ABPI)
- symptom free ≥ 1
- intermittent claudication 0.95-0.5
- rest pain 0.5-0.3
- gangrene/ ulceration < 0.2
2) Buerger’s test
- Elevate legs -> develop pallor
- If limb goes pale at angle < 20= Buerger’s angle= severe ischaemia
- Hang feet over edge of bed
- Slow to regain colour &/or dark red colour- Hyperaemic sunset foot= all capillaries open
What imaging can be used to identify chronic limb ischaemia?
- Duplex scan • No radiation/contrast • Not good in abdomen - CTA/MRA- FIRST LINE • Contrast/radiation • Can overestimate calcification/difficult in low flow states (HF) - Digital subtraction angiography • Invasive- followed by angioplasty
What medical and risk factor control can be used to treat/management can be used to treat chronic limb ischaemia?
Medical: - Antiplatelet+ statins Risk factor control: - BP control < 140/85 - Smoking cessation - Diabetes control - EXERCISE!!
What revascularisation therapies can be used to treat chronic limb ischaemia (2)? (Which is better)
- Open surgery:
• Bypass
• Endarterectomy (open artery-> remove plaque) - Endovascular intervention:
• Balloon angioplasty
• Stent placement
• Atherectomy (insert catheter-> remove plaque)
Superiority of open surgery over endovascular intervention (if short term morbidity is no issue - greater complications with open surgery)
What is acute limb ischaemia? How urgent is situation?
Sudden decrease in arterial blood flow to a limb that threatens its viability
MEDICAL EMERGENCY-> 6 hours to get to surgery
- if nothing done= amputation or death
What is the pathophysiology of acute limb ischaemia (5)? How long have symptoms lasted?
- Arterial embolus- MI, AF, proximal atherosclerosis- NOT DVT, PE
- Thrombosis of previously diseased artery
- Trauma
- Dissection
- Acute aneurysm thrombosis (for example of popliteal artery)
Symptoms last <=2 weeks
What are the risk factors for acute limb ischaemia?
- Cardiac history
- History of chronic limb ischaemia
- Risk factors for CLI
- Functional status
What are the symptoms of acute limb ischaemia (6)?
The 6 Ps: - Paralysis - Paraesthesia - Poikilothermia - Pain - Pulselessness - Pallor (When compared to the contralateral limb)
What are the complications of acute limb ischaemia (2)?
- Compartment syndrome • Muscle ischaemia – irreversible > 6-8 h • Inflammation • Oedema • Venous obstruction • Tender calf • ↑ Creatine kinase - risk of kidney failure
What is the treatment/management of acute limb ischaemia?
- Salvageable limb + only embolus= Embolectomy
- Salvageable limb+ thrombus in situ EITHER Thrombectomy/Thrombolysis OR Open embolectomy +/- bypass
- Limb not salvageable EITHER Palliation OR Amputation (depending on patient’s fitness/ wishes)
What is diabetic foot disease?
Microvascular peripheral artery disease characterised by FOOT ULCERS over bone prominences
What % of diabetic patients are affected with diabetic foot disease? What % of ulcers become infected? what % need amputated?
- 25% of diabetic patients affected
- 50% of ulcers become infected
- 20% of them need amputation
What are the risk factors for diabetic foot disease?
- Diabetes
- Infection
- Poor wound care
- Not wearing shoes
- Trauma
- Foot deformity
What preventative measures can be taken to avoid diabetic foot disease (7)?
- Wear shoes
- Check fit of footwear
- Check pressure points/ plantar surface regularly
- Prompt and regular wound care
- Glycaemic control
- Systemic antibiotics if infection
- Investigate for osteomyelitis, gas gangrene, necrotising fasciitis
Which adjunctive measures can be taken to minimise risk of diabetic foot disease (3)?
- Dressings
- Debridement - larval therapy
- Negative pressure wound closure – vacuum pump - ve pressure applied—> ↑ granulation
What is the management of diabetic Foot disease?
- Revascularisation (very distal disease)
• Distal crural (about leg/thigh) angioplasty
• Distal bypass - Amputation —> Above or below knee
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