Lymph Vessel Mapping Using Indocyanine Green Lymphography in the Nonaffected Side of Lower Leg

BACKGROUND: The lymph vessels from the dorsum and the medial ankle ascending to the medial side of the thigh toward the inguinal lymph nodes can be observed by the linear flow using indocyanine green near-infrared lymphography (ICGL). Although anatomical studies have shown the widespread existence of lymphatic vessels throughout the body, ICGL shows little linear flow. We herein report our findings of the course of lymph vessels in healthy lower limbs. METHODS: The unaffected lower limbs of 14 patients who underwent lymphaticovenular anastomosis were evaluated for this study. The results of linear flow without massage obtained using ICGL were recorded using a 3-dimensional camera. The positions of lymph vessels were measured from the baseline, which was drawn from the midline of the anterior thigh to the second toe through the middle point of the patella. The locations of the lymph vessels were analyzed using 3-dimensional images at the following 4 points: 10 cm above the knee, at the lower pole of the patella, at the middle aspect of the lower leg, and at the dorsum of the foot. RESULTS: The average distance from the baseline to the linear flow at each point was 11.39, 9.82, 4.37, and 0.97 cm, respectively. The linear flow was observed inside of the baseline at a distance equivalent to 27.2%, 30.1%, 14.8%, and 4.4% of the leg circumference. CONCLUSIONS: Lymph vessels were observed extensively in the middle lower leg. In contrast, linear flow was limited to a small area at the other measurement points. At 10 cm above the knee, 62.5% of the observed lymph vessels ran 11–12 cm inward from the baseline. Although these results can be useful when choosing incision sites for effective lymphaticovenular anastomosis, this is a pilot study of 14 patients, and studies on a large number of healthy legs need to be done in future.