*A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland †Department of Plastic Surgery, Turku University Central Hospital, Turku, Finland ‡Department of Biostatistics, University of Turku, Turku, Finland §Molecular/Cancer Biology Program and Haartman Institute, University of Helsinki, Helsinki, Finland.
BACKGROUND AND OBJECTIVE: In the lymph node transfer method, lymphatic anastomoses are expected to form spontaneously. However, lymphangiogenic growth factor therapies have shown promising results in preclinical models oflymphedema. Our objective was to define the optimal growth factor treatment to be used in combination with lymph node transfer to normalize lymphatic vascular anatomy.
METHODS: The inguinal lymphatic vasculature of pigs was surgically destroyed around the inguinal lymph node. To enhance the regrowth of the lymphatic network in the defected area, adenoviral vascular endothelial growth factor C (VEGF-C) was administered intranodally or perinodally. Control animals received injections of saline or control vector. The lymphangiogenic effect of the growth factor therapy and any potential adverse effects associated with the 2 alternative delivery routes were examined 2 months postoperatively.
RESULTS:Both routes of growth factor administration induced robust growth of lymphatic vessels and helped to preserve the structure of the transferred lymph nodes in comparison with the controls. The lymph nodes of the control treated animals regressed in size and their nodal structure was partly replaced by fibro-fatty scar tissue. Intranodally injected adenoviral VEGF-C and adenoviral vector encoding control gene LacZ induced macrophage accumulation inside the node, whereas perinodal administration of VEGF-C did not have this adverse effect.
CONCLUSIONS:Lymphangiogenic growth factors improve lymphatic vessel regeneration and lymph node function after lymph node transfer. The perinodal route of delivery provides a basis for future clinical trials in lymphedema patients.
This is presented for information only and should not be mistaken as an endorsement of lymph node transfer. This experimental treatment technique needs more extensive studies before it can be determined that it is both safe and effective for the patient. Pat O'Connor