This section is from the book "Applied Anatomy: The Construction Of The Human Body", by Gwilym G. Davis. Also available from Amazon: Applied anatomy: The construction of the human body.
At the bend of the elbow the artery lies to the inner side of the biceps tendon. It is beneath the bicipital or semilunar fascia. The upper edge of this fascia can be felt opposite the crease. In the lower third of the arm the median nerve lies close to the artery, but as the bend of the elbow is reached it diverges and becomes separated from it by the coronoid head of the pronator radii teres muscle. Superficial to the deep fascia is the median basilic vein, crossed at its upper portion by the cutaneous antebrachii medial is (internal cutaneous) nerve. The bifurcation of the brachial artery occurs opposite the neck of the radius, which is approximately a finger's breadth, or about 2 cm., below the crease of the elbow.
Fig. 301. - Ligation of the brachial artery at the bend of the (left) elbow.
Fig. 302. - Collateral circulation after ligation of the brachial artery at the bend of the elbow.
The incision is laid along the inner edge of the biceps tendon. The median basilic vein is usually more prominent than the median cephalic and can be seen obliquely crossing the artery to reach its inner side. This vein is encountered as soon as the skin is divided, hence care is necessary to avoid wounding it. It should be displaced to the inner side along with a filament of the cutaneous nerve if this is present. The incision is then deepened through the upper portion of the bicipital fascia and the artery found beneath, lying in loose fatty tissue and accompanied by two venae comites. The median nerve lies to the inner side but may be sufficiently removed not to be exposed. The needle is passed from the inner towards the outer side (Fig. 301).
On the outer side the profunda (superior) anastomoses with the interosseous recurrent (a branch of the posterior interosseous) and radial recurrent. On the inner side the superior ulnar collateral (inferior profunda) and inferior ulnar collateral (anastomotica magna) anastomose with the anterior and posterior ulnar recurrent arteries (Fig. 302).