B. Operation in lower half of arm. Here the vessel is more superficial, lying in the groove between the flexor carpi radialis and supinator longus. An incision two inches in length, and parallel with these tendons, easily exposes the artery. The nerve is still on its radial side.
C. Operation at first metacarpal. The artery may be tied easily enough in the triangular space bounded by the extensors of the thumb, on the dorsum of the proximal end of the first metacarpal bone. Skey[22] recommends a transverse,—Stephen Smith[23] and others, a longitudinal incision. The author had lately to secure the radial in its lower third, the superficialis volæ, and the radial again in the triangular space, in a case where division of the artery by a transverse cut had caused a large aneurism to form close above the annular ligament.
Table illustrating anastomotic circulation after ligature of arteries of neck and upper limb.
1. Common carotid.
(a) Across middle line: thyroids, linguals, facials, occipitals; also terminal branches of external carotids; also internal carotids by circle of Willis.
(b) Of same side: occipital with vertebral; superior thyroid with inferior thyroid, etc.
2. Subclavian, 3d part.
Suprascapular with dorsal branches of subscapular; posterior scapular with costal and muscular branches of subscapular. Thoracic anastomosis between internal mammary and intercostals, with branches of axillary.
3. Axillary and brachial. Anastomosis varies with the position of the ligature, but is very free between the various muscular branches of these vessels.