Acute limb ischemia is a sudden decrease in limb perfusion that threatens limb viability. It is usually caused by thrombosis of atherosclerotic vessels or embolism from cardiac sources or aneurysms. Clinical manifestations include pain, pallor, coldness, and pulselessness. Imaging can help determine the severity and guide treatment, which may include thrombolysis, embolectomy, bypass surgery, or amputation depending on the classification and etiology. Complications include reperfusion injury and compartment syndrome.

1. Acute limb ischemia
Mohammed AlHinai

2. Limb ischemia
Chronic limb
ischemia
Critical stenosis
(70% stenosis) of
artery for artery
compensated by
collateral vessel
Acute thrombosis of
critical stenosis
artery with well
developed collateral
vessel
Multiple lesions
affecting different
arterial segment
involving
collateral vessel
Acute limb
ischemia
Intermittent
claudication with:
- Asymptomatic
- Mild claudication
Moderate to
severe
claudication
Critical limb
ischemia

3. Acute limb ischemia :
• sudden decrease in limb perfusion that causes a potential threat to limb
viability.
Etiology
Thrombosis
(commonest )
• Usually occur as
thrombosis of
atherosclerotic
vessels.
• Or occur at site of
prior
revascularization.
• Risk factors :
- DM, HTN,
dyslipidemia
Embolism
• As emboli travel from
other sources to
narrowing artery like
atherosclerotic artery.
• Sources of emboli :
- Heart during atrial
fibrillation or prosthetic
valves and myocardial
infraction.
- Emboli from aneurysm
or atherosclerotic lesion.
Trauma
• Iatrogenic as during
angiography.
• Penetrating trauma by bone
fracture including :
- Supracondylar of femur affect
femoral artery.
- Knee dislocation affect
popliteal artery.
- Supracondylar humerus affect
brachial artery.
• Stretching artery cause
damage to intima and
thrombosis occur.

4. Different between embolic or thrombotic cause

5. Risk factors :
• Atrial fibrillation.
• Recent myocardial infarction
• Aortic atherosclerosis
• Large vessel aneurysm disease
• Prior lower extremity revascularization
• Risk factors of aortic dissection
• Arterial trauma
• Deep vein thrombosis
• Medical illness like DM, HTN, dyslipidemia.

6. Clinical manifestation
The presentation depend on the time and location of occlusion.
Early stage :
• Pain
- Sudden, severe and continue located distal in the extremity.
• Pallor :
- Cyanosis with fixed color change and might associated with progression gangrene in
late stage.
• Cold :
- Cold compare with other site of body.
• Pulselessness :
- Not feeling by hand.
- Present of pulse indicate no acute limb ischemia but if absent alone not necessary
rule in acute limb ischemia.
Late stage :
• Paraesthesia :
- In beginning, loss of touch in distal part.
- Then all sensation of distal with progression to proximal part.
• Paralysis

7. Clinical classification of acute limb ischemia
The diagnosis approach depend on the availability of
imaging modality and the time required to perfume
which should be weighed against the urgency for
treatment and that determined by clinical
classification

8. There is sufficient time to
allow for vascular imaging to
define the severity and extent
of disease.
• Noninvasive imaging include
duplex ultrasonography, CT
angiography, MR
angiography.
• Invasive include catheter
based digital subtraction
arteriography.
Imaging not immediately required as unnecessary
delay should be avoided especially in immediately
threatened.
Diagnosis

9. Management
General treatment :
• Anticoagulation
(heparin) to prevent
further thrombosis.
• Pain killer
• Management of
arrhythmia if present.
Definitive treatment :
• Depend on clinical classification
and the etiology.
ThrombosisEmbolus
ThrombolyticEmbolectomy
with imaging
I and IIA
bypassEmbolectomyIIB
AmputationangioplastyIII
Embolectomy

10. Complication (postischemic syndromes)
Reperfusion injury
• As release of activated
neutrophil, free radical,
enzymes, hydrogen ions, carbon
dioxide, potassium and
myoglobin from reperfused
tissue.
• That lead to acute respiratory
distress syndrome, mycardial
stunning, endotoxaemia and
acute tubular necrosis.
• Which in end cause organ
failure and death.
Compartment syndrome
• Endothelial cell injury during
ischemia lead to increased capillary
permeability and edema on
reperfusion.
• In the calf, the muscle are confined
within tight fascial boundaries and
cause increase in interstitial tissue
pressure which can lead to muscle
necrosis despite apparently arterial
flow.
• Management include fasciotomy to
relieve the pressure.