Sentinel lymph node biopsy

Introduction

• Breast cancer can spread from the breast to the lymph nodes in the armpit.
• Sentinel lymph nodes are the first lymph nodes to receive lymphatic fluid from the breast.
• When cancer cells begin to spread, the sentinel lymph node will be the first to be invaded.
• This surgery can diagnose and treat axillary lymph node metastasis. Further axillary treatment can be performed based on the diagnostic results of this surgery.
• Spot treatment.
• The success rate of the operation is higher than 90%.
• In the 5% case, although no metastasis was detected in the sentinel lymph node, the tumour had already metastasised to other axillary lymph nodes.

Treatment process

1. The surgery will be performed under general or local anaesthesia.
2. A small amount of radioactive isotope, blue dye, indocyanine green (ICG), iron oxide, or similar material will be injected into the tumour site to identify the location of the sentinel lymph node.
3. If radioisotopes are used, a lymph node scan must be performed.
4. The surgical incision is located in the axillary skin crease.
5. If a radioactive isotope is injected, a handheld gamma probe can be used to locate the sentinel lymph node. If indocyanine green and iron oxide are injected, other detectors will be used accordingly.
6. If blue dye is injected, the sentinel lymph node is identified using blue dye.
7. All lymph nodes with high radioactivity and/or a blue stain will be excised as samples.
8. If the frozen section biopsy result is positive, axillary lymph node dissection can be performed.
9. To suture the wound.

Risk
Anaesthetic complications

General anaesthetic

1. Cardiovascular complications: myocardial infarction or ischaemia, stroke, deep vein thrombosis, pulmonary embolism, etc.
2. Respiratory complications, pneumonia, asthma exacerbations, worsening of chronic obstructive airway disease
3. Allergic reactions and shock

Local anaesthetic

1. Local anaesthetic injected into the operative site
2. Even in rare cases, the toxicity of local anaesthetics can lead to serious complications.
3. Surgical complications (potential complications are not exhaustive)

Common surgical complications

1. The wound is painful
2. Wound infection
3. Bleeding (further surgery may be required to remove blood clots)
4. Hypertrophic scars or keloids can result in unsightly scarring.
5. Radioactive isotopes contain small amounts of radioactive material, posing less potential harm to the human body. After surgery, large

A portion of the radioactive material is removed along with the tissue sample, leaving only minimal residual radioactivity in the body.

6. In extremely rare cases, allergic reactions can occur when using radioactive drugs or blue dyes.
7. If blue dye is used, the skin will be stained and it may not fade.
8. If blue dye is used, the urine will turn green and will return to clear in about two days.
9. Lymphoedema (while possible, it's significantly less likely than with axillary lymph node dissection).
10. Nerve damage, including: the long thoracic nerve, the thoracodorsal nerve, and rarely, the brachial plexus (while possible, it is far less likely than with axillary lymph node dissection).
11. Vascular damage (while possible, much less likely than with axillary lymph node dissection).
12. Frozen shoulder and chronic stiffness (whilst possible, far less likely than with axillary lymph node dissection).
13. Numbness in the armpit (while possible, this is far less likely than with axillary lymph node dissection).
14. Seroma (while possible, far less likely than with axillary lymph node dissection).

Pre-operative preparation

1. Prepare for surgery in accordance with non-emergency surgical procedures
2. Surgery on the day of admission or the following day.
3. For general anaesthesia, a pre-anaesthetic check-up must be performed before the operation.
4. If you are preparing for general anaesthesia, you must fast for 6 to 8 hours before the operation.
5. Patients may need to go to the X-ray department for isotope injection for pre-operative imaging scans and localisation, and may require lymph node scans.
6. Change into a surgical gown before being taken to the operating theatre.
7. Pre-medication and intravenous infusion may be required.
8. Antibiotics may be required, either by injection or orally, to prevent or treat infection.
9. Please inform the doctor of any drug allergies, regular medications, or medical conditions.

Post-operative instructions
After surgery, generally, you will experience

1. Mild discomfort in the throat caused by the insertion of a nasogastric tube.
2. You may experience mild discomfort or pain at the surgical site. If the pain intensifies, please inform the nurse or doctor.
3. When undergoing general anaesthesia, nausea or vomiting can occur. If symptoms are severe, you should inform the nurse.
4. If you require more painkillers, please ask the nurse.
5. You can be discharged home on the day of surgery or the following day.

Wound care

1. Patients can shower on the first day after surgery, but should be careful to avoid wetting the wound area (keep the wound dressing dry).
2. Sutures or clips (if present) can be removed in 10 to 14 days.

Food and drink

1. You can resume eating and drinking after awakening from anaesthesia.

Post-discharge instructions

1. If any of the following events occur, please seek medical attention at the nearest emergency department.

• Worsening pain or redness of the wound
• The wound is leaking.

2. When necessary, take painkillers prescribed by a doctor
3. Gradually resume daily activities according to personal circumstances
4. Please remember your outpatient clinic appointment for suture/clip removal (if applicable) and follow-up date.

Follow-up management
Following the pathological diagnosis of sentinel lymph node samples, further surgical treatment may be required. Doctors will also recommend and arrange for other adjuvant treatments, such as chemotherapy, hormone therapy, targeted therapy, and radiotherapy, based on the patient's final condition.

Relapse
Even if the cancerous part is surgically removed, there is still a possibility of recurrence and eventual death. This is related to the condition in the early stages of the disease and its subsequent development.

Notes
This leaflet provides only basic information about the surgery, and not all possible risks or complications can be listed. The level of risk also differs for individual patients. Please contact your doctor if you have any questions.

Source: https://www.ekg.org.hk/pilic/public/surgery_pilic/surgery_sentinellymphnodedissection_0205_chi.pdf