Lower-Limb Lymphatic Drainage Pathways and Lymph Nodes: A CT Lymphangiography Cadaver Study

Area of Science:

• Anatomy
• Medical Imaging
• Lymphatic System

Background:

• Current lymphatic imaging of the lower limb lacks a standard protocol for tracer injection.
• Varied injection sites and methods are used, potentially limiting visualization of lymphatic vessels and nodes.

Purpose of the Study:

• To elucidate the three-dimensional anatomical relationships between lower limb lymphatic groups and their regional lymph nodes.
• To establish optimal injection sites for comprehensive lymphatic imaging.

Main Methods:

• 130 lower limbs from 83 human cadavers were studied.
• Indocyanine green fluorescent lymphography was performed with 19 injection sites in four foot lymphatic groups.
• CT scanning and 3D image analysis were used to map lymphatic pathways.

Main Results:

• Distinct drainage patterns were identified for anteromedial, anterolateral, posteromedial, and posterolateral lymphatic groups.
• Anteromedial and anterolateral groups drained to separate inguinal lymph nodes.
• Posteromedial group shared drainage with the anteromedial group to inguinal nodes, while the posterolateral group drained to popliteal nodes.

Conclusions:

• Standard web space injections are insufficient for visualizing all lower leg lymph nodes.
• Additional medial, lateral, and posterior foot injection sites are recommended for complete lymphatic pathway evaluation.
• Improved imaging protocols can enhance understanding and management of leg lymphedema.