Topic Overview

Pectoral Region – Dissection

Step 1: Incisions

• Make a longitudinal midline incision from the suprasternal notch to the xiphoid process.

• Make transverse incisions along the clavicle and along the costal margin.

• Reflect the skin laterally towards the axilla to expose the superficial fascia.

Step 2: Superficial Fascia

• Contains:

  • Breast and its structures.

  • Superficial veins (thoracoepigastric vein, branches of cephalic and basilic veins).

  • Cutaneous nerves (branches of supraclavicular nerves, anterior and lateral cutaneous branches of intercostal nerves).

• Carefully dissect and preserve the veins and nerves.

Step 3: Deep Fascia

• Beneath superficial fascia lies the pectoral fascia, covering the pectoralis major muscle.

• Laterally, thickens to form axillary fascia.

• At upper part, attaches to clavicle and sternum.

Step 4: Pectoralis Major

• Identify and clean pectoralis major muscle.

• Note its attachments:

  • Clavicle, sternum, upper 6 costal cartilages → lateral lip of bicipital groove of humerus.

• Nerve supply: medial and lateral pectoral nerves.

• Reflect pectoralis major by cutting near its origin and turning it laterally.

• Observe pectoral fascia and underlying clavipectoral fascia.

Step 5: Pectoralis Minor

• Lies beneath pectoralis major.

• Attachments: ribs 3–5 → coracoid process of scapula.

• Nerve supply: medial pectoral nerve.

• Important landmark: divides axillary artery into 3 parts.

• Note its relation to clavipectoral fascia.

Step 6: Subclavius

• Small muscle beneath clavicle.

• Extends from 1st rib and costal cartilage → subclavian groove of clavicle.

• Function: stabilizes clavicle; protects subclavian vessels.

Step 7: Clavipectoral Fascia

• Strong fascia between clavicle and axilla, enclosing subclavius and pectoralis minor.

• Pierced by:

  • Cephalic vein.

  • Thoracoacromial artery and vein.

  • Lymphatics.

  • Lateral pectoral nerve.

Step 8: Serratus Anterior

• Expose at lateral part of chest wall.

• Attachments: upper 8–9 ribs → medial border of scapula.

• Nerve supply: long thoracic nerve.

• Clinical: paralysis → winged scapula.

Key Structures Observed in Dissection

• Muscles: pectoralis major, pectoralis minor, subclavius, serratus anterior.

• Fasciae: pectoral fascia, clavipectoral fascia.

• Vessels: thoracoacromial artery and its branches, cephalic vein.

• Nerves: medial and lateral pectoral nerves, long thoracic nerve.

• Breast: in superficial fascia.

Clinical Importance

• Dissection helps demonstrate surgical landmarks:

  • Pectoralis minor as a guide for axillary artery division.

  • Cephalic vein in deltopectoral groove → site for central line/venous cutdown.

  • Clavipectoral fascia piercings → relevant in surgical approaches.

• Knowledge essential for breast and axillary surgeries.