Lymphatic Vessels Mapping in the Lower Extremities of a Healthy Asian Population

Abstract

Purpose: Intraoperative indocyanine green (ICG) lymphography is an effective tool to obtain real-time video images of functioning lymph vessels in edematous limbs. However, it is difficult to identify the course of lymph vessels in obese patients or patients with large dermal backflow. Without the image, surgeons have to rely on their experience when performing the skin incision to locate the lymphatic vessels. This study focused on elucidating lymphatic vessel flow patterns in healthy lower extremities in an Asian population to refer these findings for lymphedema treatment. Methods: ICG fluorescence lymphography was performed by injecting 0.2 mL of ICG into the first web space of the foot. After 4 hours, fluorescence images of lymphatic vessels were obtained and the lymphatic vessels were marked. Three landmarks were designated; the medial malleolus, the medial patellar border, and the groin femoral artery. Straight lines connecting the points were drawn, and the distance between the connected lines and the marked lymphatic vessels was measured in eight points. Results: Fifteen subjects with healthy lower extremities (15 right and 15 left) were included. The average course of the main lymph vessels passed 26.2±18.0 mm dorsally to the medial malleolus, 53.7±35.7 mm medially to the medial patellar border, and 25.5±19.2 mm medially to the three-quarters point of the upper landmark line. Conclusion: The main functioning lymphatic vessel largely follows the great saphenous vein course, passes in front of the medial malleolus, runs over the posterior border of the medial epicondyle at the knee level, and travels anteriorly toward the inguinal lymph nodes.