From Failure to Flow: Indocyanine Green Improves Preoperative Mapping for Lymphaticovenular Anastomosis After Negative Contrast-enhanced Ultrasonography.

Accurate identification of functional lymphatic vessels is essential for lymphaticovenular anastomosis (LVA) but it remains challenging. Contrast-enhanced ultrasound (CEUS) is increasingly used for preoperative mapping; however, failure to detect vessels of adequate caliber often leads to deferral of LVA. We report a case where CEUS indicated no suitable lymphatic vessels intraoperatively, yet a high-quality LVA was successfully performed using preoperative indocyanine green (ICG) lymphography-guided exploration. Preoperative ICG mapping revealed limited linear channels and dermal backflow, guiding targeted incisions. Intraoperatively, functional lymphatic vessels and suitable venules (0.3-0.4 mm) were identified despite failed CEUS-guided localization, and end-to-end anastomosis was completed. Postoperatively, maximal interlimb circumference difference decreased from 2.5 to 1.7 cm, with symptomatic relief. This is the first case demonstrating that when CEUS-guided intraoperative localization fails, individualized ICG findings can guide empirical incisions to identify better lymphatic vessels for LVA. A multimodal approach may improve patient outcomes.