Most frequently diseased arteries leading to limb ischemia :
Femoropopliteal, tibial, aortoiliac, and brachiocephalic vessels
Without the presence of collateral vessels,
peripheral nerves and skeletal muscle
may suffer irreversible changes within
4 to 6 hours of vessel occlusion
Reperfusion injury : compartment syndrome,
rhabdomyolysis, hyperkalemia, myoglobinemia,
metabolic acidosis, elevated creatine kinase
In the lower limbs, thrombotic occlusion accounts for > 80% of cases
In the upper limbs, about half of all cases of acute limb ischemia
are due to thrombosis,
while about one third are due to embolism.
Embolism : Af, Mural thrombus in the ventricle after
recent myocardial infarction, mechanical valves,
tumor emboli from atrial myxomas, vegetations from valve leaflets,
and parts of prosthetic cardiac devices
Embolism place : bifurcation of the common femoral artery, popliteal artery.
In the upper limb : the brachial artery
Hypoesthesia or hyperesthesia due to ischemic neuropathy is typically an early finding
Preservation of light touch on skin testing is a good guide to tissue viability
The pain of acute limb ischemia is not relieved by rest or gravity, is not well localized,
and can present as marked worsening of chronic pain.
Hang his or her feet over the bed (Gravity relief)
Chronic peripheral arterial disease has intermittent claudication,
brought on by exercise and relieved by rest
Ankle-brachial index : ratio of the SBP with the cuff just above the malleolus
to the highest brachial pressure in either arm
chronic peripheral arterial disease have an ABI < 0.9
while values of < 0.4 suggest severe disease.
ABI >1.3 is likely secondary to a noncompressible vessel
IV unfractionated heparin
weight-based 80 units/kg bolus followed by an infusion of 18 units/kg/h
Prevents clot extension, recurrent embolization, venous thrombosis,
microthrombi distal to the obstruction, and reocclusion after reperfusion
Aspirin (325 mg in naive patients) may enhance clot reduction through antiplatelet actions.
Stage IIb ischemia often require immediate revascularization
without additional prior diagnostic imaging.
Stage III ischemia have irreversible damage and likely require amputation.
Definitive treatment : catheter-directed thrombolysis,
percutaneous mechanical thromboembolectomy,
revision of an occluded bypass graft, and revascularization
with either percutaneous transluminal angioplasty
or standard surgery
Cilostazol, a phosphodiesterase inhibitor, as a
Class I recommendation for the treatment
of intermittent claudication.
Pentoxifylline is no longer recommended
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