What type of anesthesia is used for a sentinel lymph node (SLN) biopsy?

Anesthesia for Sentinel Lymph Node Biopsy

Sentinel lymph node biopsy can be performed safely under local anesthesia with or without sedation, though general anesthesia remains a common alternative depending on anatomic site, patient factors, and institutional practice.

Anesthetic Options by Anatomic Site

Breast Cancer

• Local anesthesia alone is feasible and effective for sentinel lymph node biopsy in early-stage breast cancer, with excellent patient tolerance and no compromise in identification rates 1
• Subareolar injection of radiotracer can be performed with lidocaine to prevent injection pain while maintaining 95% identification rates with technetium-99m-sulfur colloid alone, and 100% when combined with intraoperative methylene blue dye 2
• Ambulatory outpatient SNB under local anesthesia is safe and does not delay initiation of neoadjuvant therapy 3

Melanoma (Trunk and Extremities)

• Tumescent local anesthesia (TLA) using 0.1% prilocaine solution is sufficient as the sole anesthetic method in 74.9% of patients undergoing axillary or groin sentinel node biopsy 4
• When TLA alone is inadequate, supplemental sedation with midazolam and/or tramadol is required in 25.1% of cases 4
• Axillary biopsies require additional sedation more frequently (31.9%) compared to groin biopsies (17.3%) 4

Head and Neck (Lip SCC)

• Sentinel lymph node biopsy for squamous cell carcinoma of the lip can be performed under either local anesthesia with sedation (50% of cases) or general anesthesia (50% of cases) 5

Vulvar Cancer

• The NCCN guidelines describe the technical aspects of inguinofemoral sentinel node biopsy but do not specify anesthetic requirements, focusing instead on radiocolloid and dye injection techniques 6
• Given the anatomic similarity to melanoma groin dissections, tumescent local anesthesia with sedation backup is a reasonable approach

Practical Considerations

Advantages of Local Anesthesia

• Improved quality of life with faster recovery and same-day discharge 1
• No delays in subsequent treatment initiation 3
• Maintained diagnostic accuracy with identification rates of 95-100% 2
• Lower overall morbidity compared to general anesthesia 1

When General Anesthesia May Be Preferred

• Bilateral procedures (axilla and groin) where 25-26.6% require supplemental sedation anyway 4
• Patient anxiety or inability to tolerate local anesthesia
• Concurrent procedures (e.g., wide local excision of primary tumor performed simultaneously)
• Anatomic complexity requiring extended operative time

Technical Details for Local Anesthesia

• Tumescent technique uses dilute local anesthetic (0.1% prilocaine or lidocaine) 4
• Lidocaine can be safely mixed with radiotracer without affecting sentinel node identification 2
• Have midazolam and tramadol available for supplemental sedation if local anesthesia proves inadequate 4