Acute Arterial Occlusion

Acute arterial occlusion generally presents with an abrupt onset of pain. Classic findings-such as a cold, blue extremity, and the 5 p's (pain, pallor, paresthesia, pulselessness, and paralysis)-generally occur late. Ischemic tissue death can begin within 4 hours. Chronic arterial insufficiency also can cause ischemic changes. Worsening claudication or rest claudication may be the presenting symptom in the lower extremities that have collateral flow.

It is important to determine the cause of the obstruction because treatment can vary on the basis of whether the obstruction is due to in situ thrombosis or an embolus. Thrombosis is likely in the face of preexisting peripheral vascular disease as a result of local stasis. Embolic disease frequently occurs in patients without preexisting symptoms of peripheral arterial occlusive disease and is associated with atrial fibrillation or recent cardioversion.

Causes

The kidneys are very sensitive to the amount of blood that flows through them. Any reduction of blood flow through the renal artery can impair kidney function. If prolonged, a complete blockage of blood flow to the kidney often results in permanent failure of the kidney.

Lack of functioning of one kidney may not cause symptoms because the second kidney adequately filters the blood. High blood pressure may develop, however. If there is not a second functional kidney, blockage of the renal artery may cause symptoms of acute kidney failure.

Symptoms

Severity of symptoms depends on the location of the occlusion and on the level of collateral flow that had developed previously.

• Pain +++++
• Coldness
• Paresthesia
• Numbness
• Paralysis
• Acute embolic occlusion in digits may present rapidly with sudden pain and coldness.

Signs

• Tenderness
• Pallor
• Ischemic pain (typically worsens with passive stretch of ischemic muscles)
• Sensory deficit
• Paralysis (late)
• Pulse deficit
• Livedo reticularis (a fishnet appearance of the skin), coldness, and cyanosis
• Bruits may be heard in the presence of fistulas or aneurysms.

Treatment

• The understand role of heparin to prevent propagation of thrombus and protect the distal arterial tree.
• Understand to the benefits of mannitol for patients with advanced acute arterial occlusion.
• Understand the importance of hydration and correcting electrolyte imbalances.
• To make correct decisions concerning the proper locations and type of arteriotomy depending on whether an embolus is the likely source of acute arterial occlusion or thrombus secondary to underlying chronic arterial stenosis.
• The proper technique when using thromboembolectomy catheters.