The Axilla
Anatomy
The borders of the Axilla
Apex- costoclavicular ligament
Base- skin/ fascia
The axillary lymph nodes provide drainage from the arm, thoracic wall, and breast (20-30 lymph nodes)
*from teachmeanatomy.com
Lymph Nodes- in relation to pec minor muscle
I - Inferior and lateral to pec minor
II- Posterior
III- Medial to pec minor
Axillary sheath:
Axillary artery, vein, and brachial plexus
To dissect or not to dissect?
Axillary lymph node dissection @ time of surgery:
- Performed with primary breast procedure in pts with locally advanced (T4) or inflammatory breast cancer
- Biopsy proven axilla
Axillary lymph node dissection after SLNB when:
- 3 or more positive lymph nodes for T1-2 disease
- Positive nodes w/ T3 disease
- Positive nodes with extra-nodal extension
Anatomy Review
Thoracodorsal Nerve
is more DORSAL (ie more posterior)
innervates the latissimus DORSI
If injured = Weak pull ups and weak ADDuction
Intercostobrachial Nerve
most injured
numbness over medial proximal arm
Long Thoracic Nerve
innervates serratus anterior
If injured = winged scapula
Image from anatomynote.com
Key Points to Surgery:
Curvilinear incision 1-2cm below axillary hair line from anterior to posterior axillary fold
Critical Steps:
1) Define pectoralis muscles (can get rotter in between pec major and minor)
2) Define latissimus dorsi
3) Axillary Vein do not open axillary sheath
4) Clavipectoral fascia: expose this and obtain fat + nodes
Typical level I and II should yield >10 nodes
Level III
nodes are sent off separately (if taking/indicated)
Complications: infection, hematoma, seroma,
lymphedema, nerve injury, Stewart-Treves
Stewart-Treves
Other points:
Dissection should be inferior to AXILLARY VEIN
- Long thoracic- serratus anterior (winged scapula)
- Thoracodorsal- latissimus dorsi (weak internal rotation and ADDuction)
- Medial and lateral pectoral
- Intercostobrachial
***For melanoma****
>0.75mm; ulceration; high mitotic index; clinically positive
Take all 3 levels; use S-shaped incision