Lymphatic drainage of skin to a sentinel lymph node in a feline model.

To determine the feasibility of selective lymphadenectomy, the authors developed a feline model to identify and determine the utility of mapping dyes for this purpose. Adult cats were injected intradermally with a variety of mapping substances to determine whether the anatomic site of injection had a predictable pattern of drainage to a particular lymph node. Isosulfan blue provided the optimal mapping material. Injection of isosulfan blue intradermally into the skin of the medial thigh consistently led to coloration of the central lymph node, whereas intradermal abdominal wall injections and intradermal lateral thigh injections resulted in coloration of the lateral lymph node. Intradermal injections into skin about the perineum resulted in coloration of the most medial lymph node only. The feline model proved to a useful model to examine the utility of mapping dyes and to demonstrate dermal lymphatics. The predictable pattern of drainage of the skin in this feline model supports the feasibility of selective lymphadenectomy.