The second and third parts of both arteries are so similar to each other, that a separate account is not required for the two sides.
Ligature of Right Subclavian.—First Part.—Operation.—An incision just at upper edge of sternum and right clavicle, extending from inner edge of left sterno-mastoid transversely to outer border of right sterno-mastoid through skin, platysma, and exposing sterno-mastoid, to be joined at an angle by a second incision, which, two, three, or even four inches long, must extend along inner border of right sterno-mastoid. Flap to be raised upwards and outwards. The sternal attachment of the sterno-mastoid must then be cautiously divided, as also part or the whole of its clavicular attachment, according as room is required. The sterno-hyoid and thyroid muscles will then require similar division. The internal jugular will then be seen very prominent,[16] and will require to be drawn inwards or outwards, according to circumstances. The carotid and right subclavian arteries will then be felt lying close together crossed by the pneumogastric and recurrent nerves, the latter turning behind the subclavian. The nerves must be drawn inwards; the cardiac filaments of the sympathetic will then be observed, and drawn outwards. The subclavian vein lies below, concealed by the clavicle, and will probably not be seen during the operation. The needle should be passed round the artery from below upwards, care being taken not to injure the pleura, which lies beneath and behind the artery.
Results.—Twelve cases, all of which died; ten of hæmorrhage, one of pleurisy and pericarditis, and one from pyæmia. Attempted in one case by Mr. Butcher, but the artery was too much diseased to bear a ligature. The patient died on the fourth day.
Ligature of Left Subclavian.—First Part.—This operation, which has been described by some as impossible, has, I believe, been only once performed on the living body. Operation.—Incisions as for the preceding operation, except being on the opposite side. After the skin, platysma, and muscles have been divided, as already described, the deep cervical fascia requires division close to the inner edge of the scalenus anticus. The artery lies excessively deep, and great difficulty is experienced in avoiding injury to the pleura and the thoracic duct.
Results.—Once performed by Dr. Rodgers of New York; death from hæmorrhage on fifteenth day.
Anatomical Note.—The course of the left subclavian in its first stage is much straighter, as its origin is much deeper, than on the right side. The pneumogastric, phrenic, and cardiac nerves lie parallel to its course; the œsophagus and thoracic duct lie behind it, and to its inner side.
Ligature of Subclavian.—Second Part.—This very rare operation hardly requires a separate description, as the incisions necessary for ligature of the artery in its third part will, with very slight modifications, be sufficient for the purpose.
It has, however, special elements of danger in it, involved in the unavoidable division, of part at least, or probably the whole, of the scalenus anticus. The phrenic nerve, from its position on that muscle, requires special care to avoid dividing it, and in most cases the internal jugular vein is also in the way. The branches of the thyroid axis, which cross the neck, are quite in the line of the incision. The lowest cord of the brachial plexus lies immediately behind the artery, between it and the middle scalenus. The pleura lies just below it. The subclavian vein is generally quite safe, running in front of the scalenus anticus, and at a lower level.
The presence of the superior intercostal branch adds greatly to the danger of ligature of the vessel in this position, from its interfering with a proper clot.
Results.—Dupuytren[17] performed it successfully for a traumatic axillary aneurism. Auchincloss[18] did it for a large true aneurism, but the patient died sixty-eight and a half hours after the operation. Liston cut through the outer portion of the scalenus with success for an idiopathic aneurism. Thirteen have been collected by Wyeth with four recoveries and nine deaths.