Prevention of Lymphedematous Change in the Mouse Hindlimb by Nonvascularized Lymph Node Transplantation.

Lymphedema is a condition characterized by progressive swelling and adipose deposition that occurs commonly after lymphadenectomy. Recent clinical studies have suggested that the transfer of lymph nodes to the lymphedematous limb can improve lymphatic function. In this report, we investigate dynamic modulation of lymphatic flow and the microscopic changes of lymphatic regeneration using a lymphedema mouse model that was treated with nonvascularized lymph node transplantation. To evaluate the effect of lymph node transplantation in this model, paw volume was measured using a water displacement plethysmometer; an indocyanine green fluorescence-sensitive camera system was used. The improvement of edema was evident in the paw of the transplantation group. The abnormal fluorescence image pattern gradually improved and disappeared 4 weeks postoperatively in the transplantation group. Uptake in the transplanted lymph node was observed 4 weeks postoperatively. This finding suggested that the transplanted lymph node was engrafted. A collateral pathway was observed in the ventral area 1 week postoperatively. The collateral pathway may have contributed to the early improvement of edema. Our findings suggest that lymph node transplantation can restore lymphatic function. This result has important conceptual implications in the treatment of postsurgical lymphedema.