Tying the external carotid artery

The methods in the sections which follow for exposing and tying major vessels are among the classical methods of surgery. They are very seldom needed, yet no textbook of surgery is quite complete without them.

After a severe maxillofacial injury you may have to tie the external carotid artery. This arises from the common carotid at the upper edge of the thyroid cartilage. It runs upwards behind the neck of the mandible, and ends by dividing into the maxillary and superficial temporal arteries. It lies under the posterior belly of the digastric muscle, and its upper part lies deep to the parotid gland.

TYING THE EXTERNAL CAROTID ARTERY Tilt the table 10[de] head up to minimize venous bleeding; but not more, because this increases the risk of air embolism. Turn the patient's head to the opposite side, and extend it slightly.

Make an oblique incision from just below and in front of his mastoid process, almost to his thyroid cartilage. Divide his platsyma and deep fascia in the line of the incision, and dissect flaps upwards and downwards.

Free the anterior border of his sternomastoid and retract it posteriorly. You will see his common facial vein. Divide this between ligatures.

Carefully retract his internal jugular vein backwards, to see his common carotid artery bifurcating to form his internal and external carotid arteries. If you have difficulty in deciding which artery is which, find some branches of the external carotid and follow them backwards to the main stem (the internal carotid artery has no branches in the neck).

Pass an aneurysm needle round it, tie it with zero silk or linen, and don't divide it. Tie it as close to its origin as you can.

CAUTION ! (1) Tie the external carotid just proximal to the origin of the lingual artery. (2) Avoid the patient's hypoglossal nerve which crosses his external and internal carotid vessels and then runs anteriorly to lie on his hyoglossus muscle in company with his lingual vein. (3) Avoid irritating his carotid sinus and body in the bifurcation of his internal and external carotid vessels.

Fig. 3-6 EXPOSING THE THIRD PART OF THE SUBCLAVIAN ARTERY. If a fracture of the neck of the humerus tears the axillary artery (rare), it may cause an arterial haematoma which you can only control by tying the subclavian artery. Adapted from ''Farquharson's Textbook of Operative Surgery', edited by RF Rintoul. Churchill Livingstone, with kind permission.