Real-time Navigation for Vascularized Lymph-node Transplantation Using Projection Mapping with Indocyanine Green Fluorescence

The medical imaging projection system (MIPS) is a real-time surgical navigation device using indocyanine green (ICG) emission signals and active projection mapping. The difference between the object and the projected image is within 1 mm, and the time lag is within 0.1 seconds. We herein report the application of the MIPS to vascularized lymph-node transplantation (VLNT) surgery for lower extremity lymphedema to detect inguinal lymph nodes and perform color-coded navigation surgery for lymph-node resection. A left superficial inguinal lymph node was planned to be used as a donor for VLNT to the right lower leg in a 73-year-old woman with lower extremity lymphedema. Under general anesthesia, multiple intradermal injections of 0.1 ml of ICG were administered around the left inguinal donor site. The MIPS showed a clear linear projection image from a lateral injected point connecting to a lateral superficial inguinal lymph node. The left superficial circumflex iliac artery and vein were dissected for vascularized VLNT. Intraoperative real-time MIPS navigation continuously guided the transection plane colored by ICG fluorescence signals without shifting the visual focus from the surgical field. This is the first report of the intraoperative use of ICG projection mapping for VLNT donor-site surgery. The MIPS was able to visualize functional lymph nodes to facilitate minimally invasive donor-site surgery.