Arterial Embolism

Definition | Aetiology | Pathophysiology | Risk Factors | Signs and Symptoms | Investigations | Management | Patient Advice

Definition

Arterial Embolism occurs when a blood clot or other embolus obstructs blood flow in an artery, leading to acute ischaemia in the affected tissues or organs.

Aetiology

Common causes of arterial embolism include:

• Cardiac Emboli: Clots formed in the heart due to atrial fibrillation, valvular heart disease, or left ventricular thrombus.
• Atheroemboli: Cholesterol or plaque fragments dislodged from atherosclerotic vessels.
• Embolisation from Aneurysms: Clots or debris arising from aneurysmal sacs.
• Foreign Material: Emboli due to catheterisation or other invasive procedures.

Pathophysiology

Arterial embolism leads to acute ischaemia through the following mechanisms:

• Embolus Lodgement: The embolus obstructs an artery, blocking oxygen and nutrient supply to downstream tissues.
• Ischaemia: Tissue hypoxia results in pain, dysfunction, and potential necrosis.
• Inflammatory Response: Further exacerbates local tissue damage.

Risk Factors

Factors increasing the likelihood of arterial embolism include:

• Atrial fibrillation or other arrhythmias.
• Recent myocardial infarction.
• Prosthetic heart valves.
• Atherosclerosis or large artery plaque formation.
• Endocarditis or other cardiac infections.
• Hypercoagulable states (e.g., malignancy or inherited thrombophilias).

Signs and Symptoms

Symptoms of arterial embolism typically appear suddenly and include:

• Pain: Severe and sudden in the affected limb or organ.
• Pulselessness: Absence of pulses distal to the occlusion.
• Pallor: Pale appearance of the affected limb.
• Paresthesia: Tingling or numbness due to nerve ischaemia.
• Paralysis: Muscle weakness or inability to move the affected limb.
• Poikilothermia: Affected limb feels cold compared to the contralateral side.

Investigations

Key investigations and common positive findings include:

• Clinical Assessment: A detailed physical exam to identify the "6 Ps" (Pain, Pallor, Pulselessness, Paresthesia, Paralysis, Poikilothermia).
• Duplex Ultrasound: Non-invasive imaging showing absent blood flow in the affected artery.
• CT Angiography: Identifies the location and extent of arterial occlusion.
• Echocardiography: To detect cardiac sources of emboli, such as clots or valvular vegetations.
• Blood Tests:
  • D-dimer: Elevated in thromboembolic conditions.
  • Coagulation Profile: To identify clotting abnormalities.

Management

1. Primary Care Management

• Immediate Referral: Urgent referral to secondary care for further evaluation and treatment.
• Oxygen Therapy: To optimise oxygenation if systemic hypoxia is suspected.
• Pain Management: Use paracetamol or ibuprofen to relieve symptoms.

2. Secondary Care Management

• Anticoagulation: Administer heparin to prevent further clot formation.
• Thrombolysis: Infusion of clot-dissolving agents (e.g., alteplase) directly into the affected artery.
• Embolectomy: Surgical removal of the embolus via a catheter. Performed by a vascular surgeon.
• Bypass Surgery: Creating a graft to reroute blood flow around the blockage, if necessary.

3. Specialist Procedures

• Endovascular Thrombectomy: Performed by interventional radiologists for precise removal of emboli.
• Open Surgery: Reserved for extensive occlusions or failed endovascular treatments, performed by vascular surgeons.

Patient Advice

Key advice includes:

• Take anticoagulants or other prescribed medications as directed.
• Maintain an active lifestyle and avoid prolonged immobility to prevent further events.
• Seek immediate medical attention for symptoms such as sudden limb pain or coldness.
• Adhere to follow-up appointments to monitor vascular health and adjust treatment as necessary.