Superficial lymphatic drainage of the lower extremity: anatomical study and clinical implications.

Background: Knowledge of the lymphatic anatomy in the lower extremity is inadequate. A reevaluation is needed to assist in guiding clinical management.

Methods: A total of five lower extremities from three unembalmed human cadavers were studied. Under a surgical microscope, 6% hydrogen peroxide was used to detect the lymphatic vessels commencing from the foot, the leg, and the thigh. A 30-gauge needle was inserted into the vessels and injected with a radiopaque lead oxide mixture. The vessels were traced, photographed, and radiographed to demonstrate the superficial lymphatic pathways of the lower extremity. The final results were transferred to the computer for image analysis.

Results: Numerous lymph collecting vessels were identified in the subcutaneous tissue and the superficial femoral vascular bundle of the lower extremity. They originated beneath the dermis of each side of the toes, the foot, and the lateral side of the thigh. The diameters of the vessels varied from 0.2 to 2.2 mm. The vessels traveled in the subcutaneous tissue of the lower limb toward the popliteal, femoral, superficial, and deep inguinal lymph nodes. During their tortuous course, some vessels branched, diverged, and converged; sometimes, they anastomosed with neighboring vessels or crossed them. Most vessels converged to form larger collectors and then diverged into small branches before entering the lymph nodes.

Conclusions: Accurate lymphatic distribution within the lower extremity has been described. This information upgrades our anatomical knowledge, and the results will be of benefit for clinical management.