Axillary Lymph Nodes

What are the six groups of axillary lymph nodes?

1. Lateral / Axillary vein group
2. Anterior / Pectoral / External mammary group
3. Posterior / Subscapular group
4. Central group
5. Apical / Subclavicular group
6. Interpectoral group

The lateral / axillary group course along the axillary vein towards the bicipital groove of the humerus.
The posterior / subscapular group follows the subscapular vein and is along the posterior axillary fold and the lateral border of the scapula.
The anterior / external mammary group follows the lateral thoracic vein and is beneath the anterior axillary fold.

The central group receives drainage from froups 1-3 and 6, then drains into the apical group. The apical group can later drain into the suprascapular nodes or into the subclavian trunk.

What are Rotter's nodes?

Nodes of the interpectoral group (between the pectoralis major and minor). These drain into both the apical and central groups.

What demarcates the three levels of axillary lymph node dissection?

Level 1 - lateral to the pectoralis minor
Level 2 - deep to the pectoralis minor
Level 3 - medial to the pectoralis minor

What lymph node groups comprise Level 1 nodes

Anterior / External mammary group
Lateral / Axillary vein group
Posterior / Subscapular group

What lymph node groups comprise Level 2 nodes?

Central node group
Possibly some apical nodes

What lymph node groups comprise Level 3 nodes?

Apical / Subclavicular node group

What surgeon is credited for recognizing that breast cancer can metastasize to internal mammary lymph nodes?

W. Sampson Handley, MS, FRCS

Where do internal mammary lymphatic trunks terminate?

Some drainage to Apical / Subclavicular nodal groups
The right side enters the right lymphatic duct
The left side enters the thoracic duct

What proportion of lymphatic flow from the breast enters axillary node groups?

>75%

What are routes of lymphatic drainage of the breast?

1. Laterally, primarily to the external mammary group (anterior)
2. Medially, to the internal mammary chain
3. Transpectorally, to interpectoral (Rotter's) nodes
4. Retropectorally, directly to apical/subclavicular nodes

Late... SG

Sources:
Mastery of Surgery, 5th ed.
Lachman's Case Studies in Anatomy, 4th ed.
O'Leary's Physiologic Basis of Surgery, 3rd ed.

Axillary Anatomy

What are the borders of the axilla?

apex - cervicoaxillary canal
anteriorly - pectoralis major and minor
posteriorly - subscapularis / teres major / latissimus dorsi
laterally - bicipital groove of humerus
medially - serratus anterior
base - axillary fascia

What are the borders of the cervicoaxillary canal?

anteriorly - clavicle
posteriorly - scapula
medially - 1st rib

This aperture extends into the posterior triangle of the neck

What is the pectoral fascia?

A superficial layer investing the pectoralis major

What is the clavipectoral fascia?

A deep layer extending from the clavicle to the axillary fascia, investing the subclavius and pectoralis minor muscles

What is the costocorocoid membrane?

The superior portion of the clavipectoral fascia, above the pectoralis minor

What pierces the costocorocoid membrane?

1. cephalic vein
2. lateral pectoral nerve
3. thoracoacromial artery

What is the coracoaxillary membrane?

The inferior portion of the clavipectoral fascia, below the pectoralis minor
AKA suspensory ligament of axilla

What is the Halsted Ligament?

Dense condensation of clavipectoral fascia between the medial portion of the clavicle and the 1st rib

Invests the subclavian artery and vein as they traverse the 1st rib

What comprises the anterior axillary fold?

The lateral border of the pectoralis major

What comprises the posterior axillary fold?

Teres major and latissimus dorsi

What does the lateral pectoral nerve supply?

Pectoralis major

This is derived from the lateral cord (C5-7) of the brachial plexus and pierces the costocorocoid membrane.

What does the medial pectoral nerve supply?

Pectoralis major and minor

This is derived from the medial cord (C8, T1) of the brachial plexus and runs on the deep surface of the pectoralis minor, then pierces it to innervate both muscles.

What are the contents of the axillary sheath?

Axillary artery, 1st portion
Axillary vein
Brachial plexus

What are the borders of the 1st portion of the axillary artery?

medially - 1st rib
lateral/inferiorly - pectoralis minor

What are its branches?

Only one: the superior thoracic artery

Supplies the upper serratus anterior and intercostal spaces

What borders the 2nd portion of the axillary artery?

anteriorly - pectoralis minor
medially - medial cord of brachial plexus, axillary vein
laterally - lateral cord of brachial plexus
posteriorly - posterior cord of brachial plexus

What are its branches?

1. Thoracoacromial artery
2. Lateral thoracic artery

Both supply the pectorals. The thoracoacromial artery pierces the clavipectoral fascia and divides into acromial, deltoid, pectoral, and clavicular branches. The lateral thoracic also supplies axillary lymph nodes and the lateral breast.

What are the borders of the 3rd portion of the axillary artery?

medial/superiorly - pectoralis minor
lateral/inferiorly - teres major

What are its branches?

1. Subscapular artery
2. Anterior circumflex humeral artery
3. Posterior circumflex humeral artery

The subscapular artery divides into the circumflex scapular artery (supplies dorsum of scapula) and the thoracodorsal artery (supplies latissimus dorsi).

The anterior CHA passes deep to the biceps brachii and coracobrachialis while winding around the neck of the humerus. The posterior CHA passes through the quadralangular space of the posterior wall of the axilla along with the axillary nerve to supply the deltoid and triceps brachii. Both anastomose...

What would happen with ligation of the axillary artery proximal to the subscapular artery?

Likely nothing due to extensive scapular collateralization between the thyrocervical trunk (3rd branch of subclavian) and the subscapular artery

What would happen with ligation of the axillary artery distal to the subscapular artery?

Distal ischemia

What vessel becomes the axillary vein as it crosses the teres major?

basilic vein

What lies in the deltopectoral groove?

cephalic vein

Where does the cephalic vein drain into the axillary vein?

superior to the pectoralis minor

What does the long thoracic nerve supply?

serratus anterior

The long thoracic n is derived from roots C5-7, enters into the axilla via the cervicoaxillary canal, and lies superficial to the serratus anterior, invested in its fascia. Injury will result in "winged scapula", leading to an inability to abduct the arm above horizontal.

What does the thoracodorsal nerve supply?

latissimus dorsi

The thoracodorsal n is derived from the posterior cord of the brachial plexus and lies medial to the latissimus dorsi. Preservation is imperative for functional latissimus myocutaneous flap reconstructions.

What does the intercostobrachial nerve supply?

sensation to the skin of the apex and lateral axilla and the upper medial and inner aspect of the arm

We'll talk about axillary lymph nodes later... SG

Sources:
Moore's Clinically Oriented Anatomy, 3rd ed.
Mastery of Surgery, 5th ed.

Femoral Triangle

This one's a quickie:

Click here for a nice illustration.

What are the borders of the femoral triangle?

laterally - Sartorius
medially - Adductor Longus
superiorly - Inguinal Ligament
floor - Adductor Longus / Pectineus / Iliopsoas
roof - Fascia Lata

What are the boundaries of the femoral ring?

laterally - femoral vein
posteriorly - superior ramus of pubis / pectineus
medially - lacunar ligament / conjoint tendon
anteriorly - inguinal ligament

What are the contents of the femoral sheath?

Remember NAVEL (from lateral to medial)?

Well, the femoral nerve actually lies outside the sheath. It gives off the saphenous nerve which later accompanies the femoral artery in the adductor canal.

laterally - femoral artery
intermediate - femoral vein
medially - femoral canal (i.e. femoral hernia)

The profunda femoris a. arises laterally from the CFA 4cm inferior to the inguinal ligament then descends posteriorly. Around the same level, the great saphenous vein pierces the medial wall of the femoral sheath and drains into the femoral vein.

Late! SG

Source: Moore KL. Clinically Oriented Anatomy, 3rd ed.