Giuseppe Spinoglio, MD, Ferruccio Ravazzoni, PhD, Giampaolo Formisano, MD, Alessandra Marano, MD, Domenico Piscioneri, MD. Department of General and Oncologic Surgery, SS. Antonio e Biagio Hospital, Alessandria, Italy.
The prognosis and quality of life of patients with colorectal cancer depend on the extent of the tumor and on the quality of surgical care. A correct locoregional lymphadenectomy is mandatory for staging and treatment. The aim of this study is to evaluate the advantages of the definition of a lymph node map that should in principle permit a more extensive but guided lymphadenectomy, thus offering patients a “tailored surgery” and avoiding extended lymph nodes dissections with additional unnecessary surgical risks and perioperative morbidity. In addition, the SLN procedure could improve accurate staging and therefore subsequent oncological management by providing the pathologist with one or two lymph nodes for detailed micrometastasis evaluation.
Methods and procedures
From November 2011 to September 2013, we performed at our institution a total of 25 robotic colorectal procedures (5 right colectomies, 4 left colectomies, 12 low anterior resections and 4 abdominoperineal resections) for cancer with lymph node mapping and sentinel node biopsy with near-infrared (NIR) fluorescence DaVinci® imaging system. The technique differs in the timing of injection of the indocyanine green (ICG) to assess the lymph node map rather than to identify the sentinel lymph-node. In the case of lymph node mapping, 1 or 2 cc of a solution of 0.5% ICG (5-10 mg) is injected endoscopically around the tumor in the submucosa 3 to 24 hours before surgery. The lymph nodes are removed en-bloc if present in typical sites by a standard lymphadenectomy; however, they are removed with the “berry-picking” technique when present in unusual locations. To identify the sentinel node, the dye is injected intraoperatively into the subserosa. If the location of the tumor cannot be identified laparoscopically, the dye is injected into the submucosa by the endoscopist.
With robotic ICG-system, the lymph nodes and lymph vessels that received ICG appeared as shining fluorescent spots and streams in the fluorescence image: in the majority of cases, this allowed the detection of lymph nodes located at the origin of the superior and inferior mesenteric artery, in the interaortocaval region, in the mesorectum and along lateral pelvic walls. One of the limitations of the application is the rapid diffusion of ICG to surrounding tissues that, in a limited number of cases, prevented us from correctly identifying the lymphatic dye spread.
Our preliminary experience confirms that the application of fluorescence in robotic surgery for lymph node mapping and sentinel lymph node biopsy may provide the surgeon an important tool to optimize the staging and treatment process of patients affected by colorectal cancer. Further investigation is needed to confirm its role and to address its shortcomings and pitfalls.