Arterial Diseases of the Limbs Flashcards
What does the aorta split into in the pelvis?
Iliac arteries
What does the iliac arteries split into?
Common femoral
Branches of the superficial femoral artery
Popliteal Anterior tibial Peroneal Posterior tibial Dorsalis pedis
Where do you feel the common femoral artery?
Mid inguinal point, half way between anterior superior iliac spine and the pubic symphysis
Where do you feel the popliteal artery?
Deep in popliteal fossa
Where do you feel posterior tibial pulse?
Half way between the medial malleolus and the achilles tendon
Where do you feel the dorsalis pedis pulse?
Lateral to the extensor hallicus longus tendon
Causes of critical limb ischaemia
Atherosclerotic disease of arteries supplying lower limb
Vasculitis
Buergers disease
Risk factors for critical limb ischaemia
Male Age Smoking Hypercholesteraemia HTN DM
Classification system of critical limb ischaemia
Fontaine classification
Stages of Fontaine classification of critical limb ischaemia
Stage I - asymptomatic, incomplete blood vessel obstruction
Stage II - mild claudication, pain in the limb
Stage IIA - claudication when walking > 200metres
Stage IIB - claudication when walking < 200metres
Stage III - Rest pain, mostly in feet
Stage IV - Necrosis and/or gangrene of the limb
Why would you get pain in feet at night with critical limb ischaemia?
BP drops at night and the way you are sitting - the perfusion would decrease at night and therefore cause the pain
What to ask about the claudication
Exercise tolerance Effect of incline Change over time Relieved by rest Where in the leg Type of pain Bilateral or one leg Distance they walk when it starts Rest pain
What type of pain is claudication usually?
Burning
Signs of chronic ischaemia in lower limbs
Ulceration
Pallor
Hair loss
Investigations for critical limb ischaemia
Examination Auscultate (hand held doppler) Ankle brachial pressure index (pressure) Buergers test Hang feet off edge of bed Duplex CTA/MRA Digital subtraction angiogram
ABPI in normal vasculature value
equal or > 1
ABPI in intermittent claudication
0.95 - 0.5
ABPI in rest pain
0.5 - 0.3
What is buergers test?
Elevate legs for pallor and beurgers angle, <20 degrees = severe ischaemia
What would you see if the feet are hung off the bed in claudication and what is this called?
Slow to regain colour and a dark red colour as the blood rushes in and the feet become red
Hyperaemic sunset foot
1st line investigation for critical limb ischaemia
CTA/MRA
Definition of emboli
A blood clot, air bubble, piece of fatty deposit or other object which has been carried in the bloodstream to lodge in a vessel and cause an embolism
Definition of thrombus
A blood clot formed in situ within the vascular system of the body and impending the blood flow
Sources of arterial embolus
MI
AF
Proximal atherosclerosis
Causes of acute limb ischaemia
Arterial embolus Thrombus Trauma Dissection Acute aneurysm thrombosis i.e. popliteal
Presentation of acute limb ischaemia
6 Ps!!!
- Pain
- Pallor
- Perishingly cold
- Paraesthesia
- Paralysis
- Pulseless
Irreversibility will occur how long after symptoms present in acute limb ischaemia?
> 6 hours
Pathology of compartment syndrome
Muscle ischaemia
Inflammation
Oedema
Venous obstruction
Presentation of compartment syndrome of lower limb
Tense, tender calf
What is raised in compartment syndrome?
Creatinine kinase
Management of acute limb ischaemia
ECG Bloods Analgesia Anticoagulation Suspicion of embolus - embolectomy Suspicion of thrombus - thrombectomy/thrombolysis, open embolectomy +/- bypass Amputation Palliation
Mortality of amputation
20%
What % of acute limb ischaemia is due to emboli and to thrombus?
30% emboli
60% thrombosis
Mortality of acute limb ischaemia
22%
What % of patients with DM will develop a foot ulcer?
15%
What is key in managing diabetic foot ulcers?
Prevention
Prevention of diabetic foot ulcers
Footcare
Glycaemic control
Good wound care
Tracking infection (consider systemic Ax)
Pathology of diabetic foot disease
Microvascular peripheral artery disease affecting capillary beds - stiffening of capillaries, inflammation etc
Peripheral neuropathy - risk of trauma - standing on things without realising etc
Mechanical imbalance - pressure points in odd places and tissue damage in these areas
Susceptibility to infection (via normal skin commensals)
Footcare in DM
Always wear shoes
Check fit
Check pressure points / plantar surface of foot regularly
Prompt and regular wound care of skin breaches
What should be investigated for in diabetic foot disease?
Osteomyelitis
Gas gangrene
Necrotising fasciitis
Management of chronic limb ischaemia
Anti-platelet Statin BP control Smoking cessation Exercise Diabetic control Angioplasty/stent Surgical bypass Endovascular reconstruction
What can be used as a surgical bypass?
Femoral popliteal bypass
Femoral distal bypass to calves
Anatomical bypass - aorta to both femorals
Extra anatomical bypass
Axillo anatomical bypass (axilla to femoral))
What does a surgical bypass require?
Inflow above the blood flow A conduit - autologous - synthetic Outflow
Complications of surgical bypass
Bleeding Wound infection Pain Scar DVT / PE / MI Death (2%) Damage to nearby structures Graft failure (stenosis / occlusion) Distal emboli
ABPI in diabetics
Higher
What may T2DM have to do with their vessels and therefore how does this effect their ABPM?
Vessel classification
Abnormally high ABPM readings
What is Buergers disease also known as?
Thromboangiitis obliterans
What is buergers disease?
Small and medium vessel vasculitis that is strongly associated with smoking
Features of buergers disease
Extremity ischaemia - intermittent claudication - ischaemic ulcers Superficial thrombophlebitis Raynauds phenomenon