D154. Differentiating Afferent Lymphatic Pathways using Dual-Dye Technique during Immediate Lymphatic Reconstruction

PURPOSE: Diagnostic dyes are a vital tool in lymphatic mapping. Indocyanine green (ICG) is popularly used by microsurgeons to identify lymphatic pathways. Isosulfan blue (ISB) is favored by breast surgeons for axillary reverse mapping. The benefit of utilizing both ICG and ISB during axillary dissection and immediate lymphatic reconstruction (ILR) is reliable visualization of lymphatics intraoperatively. Using dual-dye technique, we aim to differentiate the distal and proximal lymphosomes of the upper extremity by visualizing alternate drainage into the axilla. METHODS: To identify lymphosomes of breast cancer patients receiving ILR following axillary dissection, dual-dye technique was used in the ipsilateral arm. ICG was injected distally and ISB proximally. Operative reports were reviewed to determine which dye was visualized in the axilla. Anastomotic details were documented. RESULTS: Twenty-six breast cancer patients underwent ILR. Twenty-one patients met the criteria of dual-dye technique. ICG was seen in 100% of axillary dissections. ISB was seen with ICG in 61.9% of procedures, indicating a shared lymphatic pathway. The average lymphatic lumen was 1.12mm. An average of 2.46 channels were bypassed to 1.65 veins. CONCLUSION: Dual-dye technique allows for reliable visualization of axillary lymphatic drainage by the breast and microsurgeon. We identified if lymphatic flow originated from the distal or proximal upper extremity. This technique could provide useful anatomic data in correlating the development of lymphedema to regional lymphosomes.