Anatomy: Shoulder and Axilla, Axillary Artery and Anastomoses around the Scapula

Collateral Circulation for ligation of or obstruction in any artery is important and is accomplished through the anastomosing of arteries that arise from the main channel above the stoppage with those that arise below that point.

 

Shoulder and Axilla, Axillary Artery and Anastomoses around the Scapula, 415
Anterior View - Axillary Artery and Anastomoses around the Scapula

1. Axillary Artery has 3 parts before becoming the Brachial Artery
1. Superior Thoracic artery
2. Thoracoacromial artery has 4 branches and the Lateral Thoracic Artery
1. Pectorial branch
2. Clavicular branch
3. Acromial Branch to the Acromion and acromial anastomosis
4. Deltoid Branch
3. 3 Arteries
1. Subscapular Artery with its 2 branches
1. Thoracodorsal Artery and
2. Circumflex Scapular Artery
2. Anterior Circumflex Humeral Artery
3. Posterior Circumflex Humeral Artery 

Posterior View - Axillary Artery and Anastomoses around the Scapula

1. Dorsal Scapular Artery - from around the Levator Scapulae Muscle to the Infraspinous area of the Scapula
2. Suprascapular Artery above the Trasverse Scapula Ligament and its Infraspinous Branch 
3. Acromial Branch of the thoracoacromial artery
4. Posterior circumflex Humeral Artery in the quadrangular space and ascending and descending branches
• Quadrangular space - Teres Minor, Lateral Head and Long Head of Triceps and the Teres Major Muscles
5. Circumflex Scapular Artery

Sites where anastomosis can occur

1. BETWEEN THE SUPRASCAPULAR AND THE CIRCUMFLEX SCAPULAR in the infraspinous fossa
2. BETWEEN THE DESCENDING SCAPULAR AND CIRCUMFLEX SCAPULAR along the medial border of scapular
3. BETWEEN PECTORAL BRANCHES, INTERCOSTALS, LATERAL THORACIC, OR THORACODORSAL on thoracic walls
4. BETWEEN ACROMIAL AND POSTERIOR CIRCUMFLEX HUMERAL around acromion
5. BETWEEN CIRCUMFLEX HUMERAL AND DEEP BRACHIAL in or under the triceps muscle

Special Features

1. The CIRCUMFLEX SCAPULAR ARTERY leaves the axilla through the triangular space
2. The POSTERIOR CIRCUMFLEX HUMERAL ARTERY leaves the axilla via the quadrilateral space with the axilla nerve
3. SUPRASCAPULAR NERVE AND SUPRASCAPULAR ARTERY run together, but the nerve goes under and the artery passes over the transverse scapular ligament
4. The DORSAL SCAPULAR NERVE descends with the descending branch of the transverse cervical artery.