If a fracture of the neck of a patient's humerus tears his axillary artery, it may cause an arterial haematoma which you can only control by tying his subclavian artery. You will find this a desperate procedure, if you ever have to do it.
The subclavian artery crosses the cervical pleura in the root of the neck. It passes over the first rib behind scalenus anterior which divides it into three parts. The first part is medial to this muscle, the second part is behind it. The third part of the artery, lateral to his scalenus anterior, is the part you can most easily tie. The subclavian vein lies in front of the artery and slightly inferior to it. The phrenic nerve runs down the front of scalenus anterior.
Very occasionally, you may have to explore a patient's subclavian artery in his axilla, by removing the middle piece of his clavicle and splitting the fibres of his pectoralis major, so that you can reach it.
TYING THE THIRD PART OF THE SUBCLAVIAN ARTERY This is not an easy operation, even for experienced surgeons, so avoid it if you can! If you have to do it, start by tilting the table 10[de] head up. Put the patient's arm by his side, and draw it downwards to depress his shoulder. Turn his head to the opposite side.
Make an incision 2 cm above his clavicle from the sternal head of his sternomastoid to the anterior border of his trapezius. Incise his superficial fascia, his platysma, and his deep fascia in the line of the incision. If you see his external jugular vein crossing the field, divide this between ligatures.
Retract his omohyoid upwards and you will see the third part of his subclavian artery, with scalenus anterior medially, and the trunks of his brachial plexus laterally. His subclavian vein lies in front of the artery and below it.
Don't cut his transverse cervical artery under his omohyoid muscle, or his suprascapular artery crossing his subclavian artery, because they help to maintain the collateral circulation to his arm.
If necessary, split his clavicle, divide his pectoralis major in the line of its fibres, lay his whole axilla open, and get proximal control of the artery. Pass an aneurysm needle round it, tie it with zero silk or linen, and don't divide it.
Fig. 3-7 TYING THE LEFT INTERNAL ILIAC ARTERY. A, the ureter crossing the bifurcation of the common iliac artery. B, the ureter retracted and the peritoneum incised. C, the bifurcation exposed. D, a haemostat has been passed under the internal iliac artery. E, grasping the other end of the ligature. F, the ligature ready to tie. After Lees DH and Singer A, Colour Atlas of Gynaecological Surgery, Vol. 6, p. 108. Wolfe Medical Publications, with kind permission.