SENTINEL LYMPH NODE BIOPSY (SLNB)

 

Sentinel lymph node biopsy (SLNB) is a surgical procedure used to determine if cancer, such as breast cancer or melanoma, has spread to the lymph nodes. It involves the identification and removal of the sentinel lymph node(s) — the first lymph node(s) to which cancer cells are likely to spread from a primary tumor.

 

To identify the sentinel lymph node, a dye and/or a radioactive substance is injected near the tumor. The substance or dye flows through the lymph ducts to the lymph nodes, and the first node that receives the dye is identified as the sentinel node.

​

During the procedure, the surgeon makes a small incision in the area of the lymph node and removes it. The lymph node is then examined under a microscope to check for the presence of cancer cells. If cancer is found in the sentinel node, it may indicate that the cancer has spread, and additional lymph nodes may need to be removed for further examination. If the sentinel node is free of cancer, it's likely that the cancer hasn't spread to other lymph nodes, and no further lymph node surgery is needed.

​

The sentinel lymph node is commonly located in the axilla but may be situated in the internal mammary chain or other extraaxillary sites.

​

The sentinel lymph node is the first lymph node to drain lymphatics from breast cancer and is most likely to harbor metastatic tumor cells.

​

The radioactive tracer commonly used in this precedure has very low radioactivity, and no special

protection is required around the patient.

                                                                                                 

                                                                Anesthetic Implications for SLNB

​

Anesthesia type: General anesthesia or local anesthesia + IV sedation

​

Airway: Endotracheal tube or LMA

​​

Preoperative:

​​

• Patients are frequently very anxious due to the possibility of breast malignancy

• Avoid BP cuff or IV in the ipsilateral arm

• Monitor and prevent brachial plexus injuries caused by overstretching the arm

• Breast cancer is the most common cancer among women

• In lymph node mapping, the lymphatic flow carries dye or a radioactive tracer creating a “map” of the nodes

• If the sentinel node is positive for cancer, an axillary node dissection is needed

​​

Intraoperative:

​

• May need to avoid muscle relaxants (surgeon may want nerve function monitoring)

• Operative field (chest and lymph node-bearing areas) is surveyed with a gamma probe, identifying tracer in lymph nodes

• Duration for SLNB: 10-30 minutes

• ​Position: Supine, one arm extended, one arm tucked

• EBL: Minimal

• Isosulfan blue dye may cause an artifactual drop in O2 saturation

• Isosulfan dye reaction: Itching, localized swelling, blue hives, hypotension

​

Postoperative:

​

• Smooth emergence is important

• Pain management

• Monitoring for complications

• Risk of PONV

​​

Complications:

​

• ​Allergic dye or radioisotope reaction

• Discoloration of urine and stool

• Blue staining of the skin

• Anaphylaxis

• Nerve injury: Long thoracic nerve, thoracodorsal nerve, and intercostobrachial nerve

• Lymphedema

​

Sources:

​

Elisha, S. (2010). Case Studies in Nurse Anesthesia.

​

Macksey, L. F. (2011). Surgical procedures and anesthetic implications: A handbook for nurse anesthesia practice. 

​

Jaffe, R. A. (2020). Anesthesiologist's Manual of Surgical Procedures (6th ed.). 

​

Sherwin, A., & Buggy, D. J. Anaesthesia for breast surgery. Mater Misericordiae University Hospital and University College Dublin.  Retrieved from https://www.bjaed.org/article/S2058-5349(18)30101-X/pdf

​

Singh-Radcliff, N. (2013). 5-Minute Anesthesia Consult.

​

​

​

​

 

​​

​​