Localization of Central Breast Lymphatics and Predefined Separation of Lobes along the Horizontal Septum.

Background: The predictable localization of the neurovascular supply along the ligamentous suspension, composed of the horizontal septum, vertical ligaments, and superficial fascia, has increased safety in breast reduction. Lymphatic drainage of the breast has always been described as running close to vascular supply. However, the correlation between the lymphatic course and ligamentous suspension has not yet been considered. This study aimed to visualize the relationship, direction of lymphatic flow, and predefined separation of lobes along the horizontal septum. Methods: To investigate central drainage, methylene blue was injected subareolarly in five breasts of female cadavers before blunt preparation of the horizontal septum in anatomical studies. To visualize central and peripheral drainage, lymphographin was injected into one of the three different sites in 14 breasts; the dynamic flow of drainage was observed during subsequent septum-based breast reductions in clinical settings. Results: In all anatomical studies, a predefined section of the glandular layers allowed access to central clearance along the stained horizontal septum. Clinical investigations similarly showed clearance along the corresponding part of the ligamentous suspension, most reliably along the horizontal septum. The affected quadrant of the breast, its relation to the nipple-areola complex, and the anterior-posterior axis toward the thoracic wall mainly determine the direction of lymphatic flow. Interconnections along the ligaments may explain the unpredictability of final clearance directions. Conclusions: This study shows the horizontal septum as a guiding structure for central mammary drainage. This may encourage a septum-based approach for refinement of procedures such as oncoplastic, irradiation, and lymphedema treatments.