Carotid Endarterectomy

Preoperative Preparation

  • Duplex scans of the carotid artery and CT scan of brain are mandatory.
  • Carotid angiogram is helpful to see the intracranial anatomy and status of the aortic arch branches.
  • The risk of stroke should be thoroughly explained to the patient and his family.

Anaesthesia

General or local. Intraoperative monitoring highly recommended by stump pressure, transcranial Doppler, EEG or TCO2

Position

Supine with the head slightly extended and turned toward the contralateral side.

Incision

Oblique along the anterior border of the sternocleidomastoid extending from the mastoid process to the sternoclavicular joint.

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Procedure

  • Mobilise the anterior border of sternocleidomastoid and retract it posteriorly.
  • Expose the carotid sheath.
  • Divide the facial vein, which crosses the carotid artery at the upper end of the wound.
  • The omohyoid muscle can be retracted inferiorly or divided at the lower end of the wound.
  • Identify and protect the hypoglossal nerve, which can be lifted off the carotid artery superiorly.
  • The vagus nerve lies posteriorly and deep to the artery and usually is out of harm’s way, but it should be noted.
  • Using gentle sharp dissection, expose the common carotid artery and trace the internal carotid artery up to a point where it is relatively disease free. Take extreme care not to displace the vessels from their bed and avoid any rough handling as this might dislodge of loose thrombotic plaque.
  • Pass rubber slings around common carotid, internal carotid and origin of the external carotid arteries.
  • After 5,000 units of heparin have been given intravenously, apply vascular clamps to the external and common carotid arteries.
  • The stump pressure in the internal carotid artery can be measured with a needle probe connected to a transducer – a mean pressure > 50mm Hg indicates adequate perfusion of the relevant cerebral hemisphere through the circle of Willis, fed by collateral circulation. Lower pressures indicate the use of a shunt to protect cerebral circulation during endarterectomy. Some prefer to use electroencephalographic monitoring to gauge the adequacy of collateral blood flow and the requirement for intraluminal shunting.
  • After application of clamps to internal carotid, common carotid and external carotid, make a longitudinal arteriotomy commencing below the bulb and extending over the internal carotid beyond the distal limit of the atherosclerotic plaque.

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  • Start endarterectomy in the distal common carotid artery using a blunt dissector. The cleavage plane is identified between media and the adventitia. This dissection is carried circumferentially leaving a smooth, glistening reddish brown arterial wall behind.

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  • ┬áCut the proximal end of this endarterectomised plaque with a scissors near the lower end of the arteriotomy.
  • The endarterectomy then proceeds in the same plane with gentle feathering at the distal boundary of the plague in the internal carotid artery. Tacking sutures can be applied at this end to prevent subintimal dissection. All residual debris is removed with forceps in a circumferential direction.
  • Heparinized saline is flushed through the field of endarterectomy.
  • A patch angioplasty with Dacron, PTFE or autologous vein can be used for a small carotid artery or the arteriotomy is closed with a running suture. If used, the shunt is removed near completion of closure.
  • Clamps are removed sequentially starting from common carotid, then external carotid followed by internal carotid artery.

Closure and Drainage

In layers over a closed suction drain.

Postoperative management

Includes careful monitoring of pulse rate and blood pressure. Longterm aspirin antiplatelet therapy.

Main Postoperative Complications

Early include neck haematoma, damage to cranial nerves X, XI and XII, and stroke. Later on, re-stenosis and occlusion.