Peripheral arteries may be acutely occluded by a thrombus, an embolus, aortic dissection, or acute compartment syndrome.
Acute peripheral arterial occlusion may result from:
Rupture and thrombosis of an atherosclerotic plaque
Embolus from the heart or thoracic or abdominal aorta
Acute compartment syndrome
Symptoms and signs are sudden onset in an extremity of the 5 P’s:
Pain (severe)
Pallor
Paresthesias (or anesthesia)
Polar sensation (coldness)
Pulselessness
Outcomes are best with early diagnosis, but pain, generally the earliest symptom, is nonspecific. However, the pain of acute arterial occlusion can be out of proportion to physical findings. Thus, acute peripheral arterial occlusion should be considered in patients at risk (eg, with known or suspected peripheral arterial disease) who have limb pain disproportionate to physical findings, particularly if onset is sudden.
The occlusion can be roughly localized to the arterial bifurcation just distal to the last palpable pulse (eg, at the common femoral bifurcation when the femoral pulse is palpable; at the popliteal bifurcation when the popliteal pulse is palpable). Severe cases may cause loss of motor function. After 6 to 8 hours, muscles may be tender when palpated.
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Diagnosis is clinical. Immediate angiography is required to confirm location of the occlusion, identify collateral flow, and guide therapy.
Treatment
Embolectomy, thrombolysis, or bypass surgery
Treatment consists of embolectomy (catheter or surgical), thrombolysis, or bypass surgery. The decision to do surgical thromboembolectomy vs thrombolysis is based on the severity of ischemia, the extent or location of the thrombus, and the general medical condition of the patient.
A thrombolytic (fibrinolytic) medication, especially when given by regional catheter infusion, is most effective for patients with acute arterial occlusions of < 2 weeks and intact motor and sensory limb function. Tissue plasminogen activator and urokinase are most commonly used. A catheter is threaded to the occluded area, and the thrombolytic medication is given at a rate appropriate for the patient’s size and the extent of thrombosis. Treatment is usually continued for 4 to 24 hours, depending on severity of ischemia and signs of thrombolysis (relief of symptoms and return of pulses or improved blood flow shown by Doppler ultrasonography). In a large observational study, between 1998 and 2009, 1-year amputation rates declined from about 15% to 11% although 1-year mortality remained the same at about 40% (1). A
Treatment reference
1. Baril DT, Ghosh K, Rosen AB. Trends in the incidence, treatment, and outcomes of acute lower extremity ischemia in the United States Medicare population. J Vasc Surg 2014;60(3):669-77.e2. doi:10.1016/j.jvs.2014.03.244
Key Points
Acute peripheral arterial occlusion is characterized by severe pain, cold sensation, paresthesias (or anesthesia), pallor, and pulselessness in the affected extremity.
Treatment consists of embolectomy, thrombolysis, or bypass surgery.
Despite treatment, about 11% of patients with acute arterial occlusion require limb amputation.
