Additional energy requirements during lactation

• 500 kcal/day

Serratus anterior – long thoracic nerve (winged scapula), lateral thoracic artery

• Shoulder pain, inability to raise arm above shoulder level (limited ABduction)
• Medial chest wall

Latissimus dorsi - thoracodorsal nerve

• Weakened arm pull-ups and ADduction
• Difficult arm extension and internal rotation
• Lateral chest wall

Medial pectoral (thoracic) nerve – pec major and minor

Lateral pectoral nerve – pec major – injured during level III node takedown

• Muscle atrophy, limitation of shoulder motion

Intercostobrachial nerve – MC nerve injured during mastectomy

• Numbness and pain of the upper inner arm

Thoracodorsal Neurovascular Bundle

• Runs in the mid axilla just inferior to the axillary vein
• Includes thoracodorsal nerve and thoracoepigastric vein
• Latissimus dorsi - arm ADduction, arm extension, internal rotation
• Serratus anterior - long thoracic nerve, runs parallel to the chest wall, more proximal in the axilla than the thoracodorsal nerve

Upper outer quadrant has abundance of epithelial tissue

Frequent site for benign and malignant breast disease