Feasibility of Lymphatic Mapping of Second Echelon Lymph Nodes With Methylene Blue

After lymphatic mapping of the SLN with Tc-99 sulfur colloid only, the second-echelon lymphatic mapping was then performed with methylene blue dye by injecting the SLN with 0.05-0.10 cc non dilute methylene blue and tracing via the efferent lymphatic channel to the second echelon lymph node (Figure 1). For our initial patients a 27 gauge needle and 3cc syringe was utilized but this was modified over the study to a 30 gauge needle and 1cc syringe. The blue efferent lymphatic was traced with minimal spreading of the surrounding tissue to visualize its drainage into the next lymph node(s). A second echelon lymph node was considered any blue lymph node or any lymph node with blue dye leading directly into it. The number of second echelon lymph nodes was recorded. The second-echelon lymph node(s) was not removed.