Dual Fluorescent Tracers for Surgical Guidance: Preventing Donor-site Lymphedema in Vascularized Lymph Node Transfer.

[INTRODUCTION] Vascularized lymph node transfer (VLNT) restores physiological lymphatic function. Although effective, postoperative impairment of donor-site lymphatic function and iatrogenic lymphedema following lymph node transfer remains a pressing concern.

[METHODS] Prospective analysis of VLNT patients undergoing dual fluorescent tracers-assisted harvest was performed at our institution from September 2013 to April 2022. Reverse lymphatic mapping of the lower extremity was performed with indocyanine green (ICG). Blue dye was utilized in both white light and near-infrared spectra for visualization of donor-site lymphatic structures. Demographics, intraoperative details, and surgical outcomes were recorded.

[RESULTS] Twenty-five patients were included. Median age was 52.9 years with a body mass index of 29.1 kg/m and mean follow-up of 44 months (range 24 to 90 months). Lymphedema stage ranged from Campisi 2 to 4. Inguinal VLNT was performed in 13 patients, and 12 patients received combined VLNT and free flap breast reconstruction. No patients required change in lymph node donor site intraoperatively. All ICG stained nodes were preserved in situ. No cases of iatrogenic lower extremity lymphedema were observed. Postoperative bioimpedance spectroscopy, circumferential, and volumetric measurements of the donor-site limb did not show evidence of subclinical or clinical lymphedema. The donor site healed appropriately in 92% of patients; one patient developed methylene blue-induced skin necrosis.

[CONCLUSION] Reverse lymphatic mapping and surgical guidance with dual ICG and blue dye fluorescent tracers provides surgeons with real-time surgical guidance without radioisotope, improves surgical visualization in both white light and near-infrared spectra, and avoids iatrogenic lymphatic dysfunction in the donor limb.