Axillary Lymph Node Dissection

I perform a level II clearance through an axillary skin crease incision with formal identification and preservation of the axillary vein, thoracodorsal bundle and long thoracic nerve. I maintain my dissection below the axillary vein and the medial cutaneous nerve of the arm, and am cognizant of the medial pectoral nerve when I retract Pectoralis minor.

Boundaries of the axilla

• Medial - Serratus anterior muscle and chest wall
• Posteriorly Subscapularis, teres major and latissimus dorsi
• Lateral - Medial aspect of the humerus (Intertubercular sulcus - bicipital groove)
• Anterior Pectoralis minor, Pectoralis major muscles and clavipectoral fascia
• Apex - Clavicle, first rib and scapula
• Base - Axillary fascia and skin of the armpit

Lymph node levels

• Level I – lateral to pec minor.
• Level II – posteriorly to pec minor.
• Level III – medially to pec minor
• Rotter’s node – in between pec minor and pec major.

Clinical considerations

• Axillary node clearance should strive to preserve the thoracodorsal pedicle, long thoracic nerve, medial pectoral nerve, and intercostobrachial nerve.
• The thoracodorsal supplies the LD, it is vital to preserve this if you want to perform a LD reconstruction.
• The thoracodorsal nerve supplies motor function to LD - injury to this effects shoulder extension and rotation.
• The long thoracic nerve supplies the serratus anterior and injury to this results in winged scapula.

Surgical access

• If the patient is undergoing a modified radical mastectomy then the lateral extension of the mastectomy incision is used.
• Otherwise, and oblique incision at the inferior margin of the axillary hairline extending from the lateral edge of pectoralis muscle to the medial edge of latissimus dorsi is used.
• Skin flaps should be raised – superiorly to the level of the axillary vein and inferiorly to the level of the 4th-5th rib.

Identification of Axillary Vein

1. Retrograde dissection by identifying angular veins draining into Thoracodorsal Vein
   • Thoracodorsal vein then followed cranially until it enters Axillary Vein
   • Latissimus dorsi tendon can be followed cranially also
2. Palpation of Axillary Artery at apex of Axilla – vein lies anterior to the artery and posterior to the junction of the Clavicle and 1st Rib
3. Retraction/Transection of Pectoralis Minor – located posterior to the medial edge of muscle
4. Find the lateral thoracic vein and artery and chase the vein back to the auxiliary vein
5. Find the lateral thoracic vein and artery and chase the vein back to the auxiliary vein

Operative steps

• The clavipectoral fascia should be identified and opened.
• Pec major and minor
  • Blunt dissection to identify the lateral border of pec major which is retracted laterally to expose pec minor
  • Careful to not injury medial pectoral nerve. The medial pectoral nerve wraps around the lateral edge of pec major and supplies both pectoral muscles.
• Axillary vein
  • Dissection continue up through the axillary fat pad superiorly to identify the axillary vein. The vein will course horizontally in the dissection field and be anterior and inferior to the axillary artery.
  • Dissection should continue laterally from this lateral edge of pec minor until the lateral thoracic vein (LTV), approximately 2-3cm from the lateral chest wall is identified.
  • The LTV drains the lateral portion of the breast and can be ligated and divided if needed, but only after the thoracodorsal bundle has been identified.
  • This vein can also be used to find the axilla vein if required
• Thoracodorsal bundle
  • Located deep and slightly lateral to the LTV is the TDB, which includes the nerve, artery, and vein running to latissimus dorsi muscle.
    • The nerve is located laterally, artery in the middle, and vein medially (same as the femoral canal!)
    • The TDB should be identified and preserved along its entire course to its insertion into the medial edge of LD.
• Intercostal brachial nerves
  • Approximately 2cm inferior to the axillary vein is the Intercostal brachial nerve. This runs from the second intercostal rib space and transverses across the axilla to provide sensory innervation to the medial portion of the upper inner arm.
  • It courses anterior to the TDB. An attempt to preserve it should be made.
• Long thoracic nerve
  • The long thoracic nerve runs parallel to the TDB along the lateral deep surface of the serratus anterior muscle fascia and provides motor function to the muscle.
• Dissection
  • Once all the axillary anatomic strictures have been identified, resection of the level I and II nodes can be performed.
  • Superior dissection begins under the pectoralis minor muscle to remove level II lymphatics.
  • Lymphatic channels and blood vessels should be clipped or ligated.
  • After a superior dissection is complete, the specimen can be retracted inferiorly and the remained of the lymphatic tissue removed.
  • Dissection continue inferiorly and then stop at angular vein
• 15fr blake drain

Rationale:

• Stages disease & dictates need for adjuvant treatment
• Provides local control of axilla - local recurrence < 1% (0.4%)
• Possible survival implications – unknown if ↑s survival

Procedure

• Level II dissection is operation of choice
• Level III if macroscopic evidence of tumour at level II
  • No improved DFS/OS after routine level III AD
  • Up to 25% will have level III involvement if Level I involved
• Aim to remove 20 nodes for optimal staging

Complications

• Lymphoedema
  • 15%
  • Physical therapy, arm strengthening, and stretching; compression garments
• Limitations in postoperative shoulder and arm mobility
• Prolonged postoperative pain
• Cording
  • Cording of the axilla and upper arm, is a self-limited, harmless condition
  • Believed to be caused by thrombosis in subcutaneous veins and ligation of veins after axillary dissection
• Paraesthesia
  • intercostal bracial nerve
    • Upper inner arm
• Winged scapula - LTN
• Weakness of the arm with respect to extension, adduction and medial rotation - TDB/Lats