Topic Overview

Axillary Vein

Anatomy

• Origin → continuation of basilic vein at the lower border of teres major.

• Termination → continues as subclavian vein at the outer border of 1st rib.

• Position → lies anteromedial to axillary artery throughout its course.

---

Tributaries

• Correspond roughly to branches of axillary artery:

  • Veins accompanying superior thoracic, thoracoacromial, lateral thoracic, subscapular, circumflex humeral arteries.

• Major superficial tributaries:

  • Cephalic vein (joins near 1st part of axillary vein).

  • Basilic vein (forms axillary vein).

---

Relations

• Anteriorly → skin, fascia, pectoralis major.

• Posteriorly → axillary artery and brachial plexus cords.

• Medially → ulnar nerve, medial cutaneous nerves of arm and forearm.

• Laterally → axillary artery.

---

Clinical Anatomy

• Central venous access: axillary vein can be cannulated, safer than subclavian in some cases.

• Injury: during trauma or surgery, injury may cause severe hemorrhage or air embolism (negative pressure in thorax).

• Compression: in axillary swellings, enlarged nodes or aneurysms may compress the vein → arm edema.

• Thrombosis: effort-related thrombosis (Paget-Schroetter syndrome) can occur in athletes due to repetitive shoulder movements.

• Surgical landmark: important in axillary dissections (breast carcinoma surgeries).

 

Axillary Lymph Nodes

General Features

• About 20–30 lymph nodes present in axilla.

• Function: drain lymph from upper limb, breast, and thoracic wall.

• Clinically important as the main pathway of breast carcinoma spread.

---

Groups of Axillary Nodes

1. Pectoral (Anterior) Group

• Location → along the lateral thoracic vessels, near lower border of pectoralis minor.

• Drainage → anterior thoracic wall (including most of breast).

• Clinical → first involved in carcinoma of breast.

2. Subscapular (Posterior) Group

• Location → along subscapular vessels, near posterior axillary fold.

• Drainage → posterior thoracic wall, scapular region.

3. Humeral (Lateral) Group

• Location → along axillary vein, medial to humerus.

• Drainage → upper limb (except lymphatics following cephalic vein, which drain to apical nodes).

4. Central Group

• Location → deep in axillary fat, near base of axilla.

• Receive → lymph from pectoral, subscapular, and humeral groups.

• Drain into apical nodes.

5. Apical Group

• Location → apex of axilla, near 1st rib and clavicle.

• Drainage → central nodes, cephalic vein lymphatics, upper part of breast.

• Efferents → form subclavian lymph trunk → drains into thoracic duct (left) or right lymphatic duct (right).

---

Lymphatic Drainage Pathway (Summary)

• Breast → mainly to pectoral nodes.

• Upper limb → mainly to humeral nodes.

• Back → to subscapular nodes.

• All → converge on central nodes → apical nodes → subclavian trunk → venous system.

---

Clinical Anatomy

• Breast carcinoma:

  • 75% of lymph from breast drains to axillary nodes.

  • Axillary nodes (especially pectoral group) are first involved.

  • Spread to apical nodes → systemic dissemination.

• Axillary clearance (surgery):

  • Done in breast cancer operations.

  • Must preserve long thoracic nerve (to serratus anterior) and thoracodorsal nerve (to latissimus dorsi).

• Tuberculosis: axillary nodes may be enlarged in TB infection.

• Sentinel lymph node biopsy: identifies first draining node of breast → used to detect metastasis.

 

 

Clinical Anatomy of Axillary Lymph Nodes

1. Carcinoma of Breast

• Most important clinical relevance.

• 75% of lymph from breast drains to axillary nodes, especially anterior (pectoral) group.

• Spread pattern:

  • Pectoral → central → apical → subclavian trunk → venous system.

• Clinical signs:

  • Hard, immobile axillary nodes in carcinoma.

  • Skin dimpling, nipple retraction, peau d’orange (from lymphatic obstruction).

• Contralateral spread → via parasternal nodes, but axillary involvement is usually earliest.

---

2. Axillary Node Dissection

• Performed in carcinoma breast to remove involved nodes.

• Structures to preserve during dissection:

  • Long thoracic nerve (to serratus anterior) → injury causes winged scapula.

  • Thoracodorsal nerve (to latissimus dorsi).

• Used for staging and treatment of breast carcinoma.

---

3. Sentinel Lymph Node Biopsy

• First node draining breast (usually anterior group) identified using dye or isotope.

• If uninvolved → full axillary clearance can be avoided.

• Minimizes morbidity (lymphedema, nerve injury).

---

4. Tuberculosis

• Axillary nodes often enlarged and matted in tuberculous lymphadenitis.

• May form cold abscesses that track along fascial planes.

---

5. Infections of Upper Limb

• Minor infections of hand or arm → lymphadenitis in axillary nodes (painful, tender swelling).

---

6. Systemic Disease

• Lymphomas and leukemias present with generalized lymphadenopathy, often involving axillary nodes.

---

7. Surgical & Clinical Significance

• Sentinel node biopsy → gold standard for detecting early metastasis.

• Axillary swellings → differential diagnosis includes lipoma, abscess, aneurysm, and lymphadenopathy.

• Metastatic spread → involvement of apical nodes indicates advanced disease.

• Postoperative complication → removal of nodes may cause lymphedema of upper limb.