The initial route of metastases in most patients with melanoma is via the lymphatics to the regional nodes. However, routine lymphadenectomy for patients with clinical stage I melanoma remains controversial because most of these patients do not have nodal metastases, are unlikely to benefit from the operation, and may suffer troublesome postoperative edema of the limbs. A new procedure was developed using vital dyes that permits intraoperative identification of the sentinel lymph node, the lymph node nearest the site of the primary melanoma, on the direct drainage pathway. The most likely site of early metastases, the sentinel node can be removed for immediate intraoperative study to identify clinically occult melanoma cells. We successfully identified the sentinel node(s) in 194 of 237 lymphatic basins and detected metastases in 40 specimens (21%) on examination of routine hematoxylin-eosin-stained slides (12%) or exclusively in immunohistochemically stained preparations (9%). Metastases were present in 47 (18%) of 259 sentinel nodes, while nonsentinel nodes were the sole site of metastasis in only two of 3079 nodes from 194 lymphadenectomy specimens that had an identifiable sentinel node, a false-negative rate of less than 1%. Thus, this technique identifies, with a high degree of accuracy, patients with early stage melanoma who have nodal metastases and are likely to benefit from radical lymphadenectomy.

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.

FMT was successful and safe in this cohort of patients with severe or complicated CDI. Primary and secondary cure rates were 88.2% and 94.1%, respectively.