Identification of lymph vessels using an indocyanine green camera-integrated operative microscope for lymphovenous anastomosis in the treatment of secondary lymphedema

Objective: Lymphedema is a debilitating disease that impairs a patient's quality of life. Although lymphovenous anas-tomosis (LVA) can cure lymphedema, successful LVAs rely on the precise identification of the lymph vessels. In the present study, we assessed the use of a near-infrared camera-integrated operating microscope for preoperative mapping of the lymphatic vessels and evaluated the outcome of LVAs in patients with secondary lymphedema of a limb. Methods: We retrospectively reviewed patients with secondary unilateral lymphedema who had undergone LVA surgery with the lymph vessels identified using a near-infrared camera-integrated operating microscope (Moller 3-1000; Moller-Wedel Optical GmbH, Wedel, Germany) between 2020 and 2021. The lymph vessels identified using near-infrared fluorescence lymphography, diameter of the vessels used for anastomosis, anastomosis configuration, and perioperative limb circumference were recorded. Results: Overall, 35 LVAs were performed in six patients with secondary lymphedema, with a mean number of 5.8 LVAs per limb. The anastomotic configurations were end-to-end in 26 LVAs, side-to-end in 2 LVAs, and end-to-side in 7 LVAs +/- 0.18 mm) and that of the vein from 0.4 to 1.2 mm (mean, 0.75 +/- 0.21 mm). The changes in the lymphedema index and estimated limb volume indicated a post-operative decrease in edema. Conclusions: We found a near-infrared camera-integrated operating microscope useful for the preoperative identification of functional lymph vessels. Our results have shown that microsurgical LVAs can be performed using an integrated indocyanine green camera without an independent indocyanine green detector.