Lymphatic Wire-Guided Identification of Proximal Collecting Lymphatic Vessels in Advanced Lower Extremity Lymphedema.

In advanced lower-limb lymphedema, identifying functional lymphatic vessels suitable for lymphaticovenular anastomosis (LVA) has become increasingly complex because of vessel degeneration and depth. This study introduces the use of a novel intraluminal guidewire system (LymTracer) to identify functional collecting lymphatic vessels in patients with advanced lymphedema. Between December 2022 and December 2024, 21 patients with advanced secondary lower limb lymphedema underwent LVA. All patients had limited ICG-detectable lymphatic vessels in the distal lower legs. The LymTracer was inserted into the functional lymphatic system at the distal site and advanced proximally under fluoroscopy. If the wire advanced ≥10 cm proximally, an additional incision was made for a second LVA. The wire advanced proximally in 11 of 21 patients, allowing identification and anastomosis of previously unvisualized proximal lymphatic vessels. The LymTracer advanced an average of 11.3 ± 10.0 cm. These vessels were significantly deeper (13.2 ± 3.7 mm vs. 6.2 ± 2.2 mm, p = 0.00009) but similar in diameter. Bioimpedance showed greater water reduction in the additional group (13.0 ± 8.8% vs. 3.0 ± 9.0%, p = 0.03). In our cohort, LymTracer enabled proximal anastomosis in approximately half of advanced cases and was associated with greater limb water reduction. This technique demonstrates the feasibility of using LymTracer as an intraoperative adjunct to identify proximal collecting lymphatics beyond regions of dermal backflow. LymTracer may provide an additional option for surgical planning in advanced lymphedema when conventional imaging fails to identify suitable proximal lymphatic vessels.