Evaluation of the Effect of Vascularized Lymph Nodes Transfer on Lymphatic Drainage and Local Immune Function in an Experimental Rat Lymphedema Model

Abstract

INTRODUCTION: This study aimed to investigate the number of vascularized lymph nodes (VLN) transferred and the effect on lymphatic drainage and local immune function in an experimental rat lymphedema model. METHODS: Lymphedema in the lower extremity was created by removing the inguinal lymph nodes and popliteal lymph nodes followed by treatment with 20 Gy radiations in the Sprague-Dawleys rat (10-12 weeks old, weighted 350 g to 400 g). The volume of the limb was calculated from measurements taken by Micro-CT scan. The different numbers of VLN, group A (LN-1) and group B (LN-3), from the omentum was transferred to the groin site of the lymphedematous limb and anastomosed to the femoral vessels. The volume change was evaluated at one and three months after surgery. In addition, the outcomes of lymphoangiogenesis and immune function of the transferred LNs were evaluated with immunochemistry stain (CD3, VEGF-C) and cytokine expression (IL-2, IFN-γ). RESULTS: The reduction rate of lymphedema was depended on the number of VLN transferred. Compared with pre-operation, the volume of the lymphedematous limb was significantly restored in LN-3 after one month. There were significant expressions of VEGF-C and CD3 in the transferred VLN. The lymphocytes in the transferred VLN could also express the inflammation cytokines (IL-2 and IFN-γ) after Concanavalin A stimulation. CONCLUSION: There was a positive correlation between the number of VLN transferred to the lymphedematous limb and the improvement in the lymphatic drainage. The vascularized lymph nodes maintained their functional lymphocytes activity after transfer.