Background: Changes of the lymph flow from the chest wall after mastectomy and sentinel lymph-node biopsy (SLNB) or axillary lymph-node dissection (Ax) has yet to be understood. This study aimed to investigate the effect of axillary surgery on lymphatic flow from the chest wall in patients who have undergone mastectomy, including those have undergone breast reconstruction using deep epigastric artery perforator (DIEP) flap and vascularized lymph-node transfer (VLNT).
Methods Following mastectomy in 100 breasts, the directions of lymph flow from the chest wall was compared between the SLNB omission, SLNB, Ax, and Ax followed by VLNT groups using indocyanine green (ICG) lymphography in cross-sectional study. In order to visualize differences in the direction of lymph outflow in each group, a breast chart mimicking the radar chart was created. Lymph flow on the deep DIEP flap was also investigated.
Results: In the SLNB omission group, the direction of ICG drainage in the chest was toward the ipsilateral axilla in all breasts (100%). Lymph flow directing to the ipsilateral axilla was observed more frequently after SLNB than Ax (48% vs. 12.5%; p = 0.005); however, no significant difference was observed in the frequency of contralateral axillary route adoption between them (8% vs. 15%; p = 0.65). In the VLNT group, lymph flow to the ipsilateral axilla was not observed at a significantly higher frequency than in the Ax group (12.5% vs. 12.5%, p = 1.00). On the transferred DIEP flap, the lymph flowed anterograde or retrograde parallel to the anatomic course of the lymphatic vessels in all breasts.
Conclusion: To visualize the direction of lymph flow of the chest following mastectomy, ICG lymphography may be useful to discern the direction in which malignant neoplasms, including breast implant-associated anaplastic large-cell lymphoma, are transported and to plan for lymph flow restoration.