Fluorescence Image Guided Foregut Surgery

In cancer surgery, an oncological resection involves the resection of the primary lesion but also of the loco-regional lymph nodes.In the large retrospective study of the Global Group of esophageal cancer collaboration (WECC) involving 3,572 patients having had resection of the main tumor (60% adenocarcinomas, 40% squamous cell carcinomas), a high total number of resected lymph nodes has been shown to be an independent prognostic factor of improved survival after esophagectomy for esophageal or gastroesophageal junction cancer. The maximum survival at 5 years is modulated by the T classification: it is recommended to resect 10 lymph nodes for a "pT1" stage tumor (pathologic tumor stage 1), 20 for a "pT2" stage and at least 30 for a "pT3" / "T4" stage. This number is important in terms of staging, the decision of adjuvant treatments and prognostic. A recent European study showed that the average number of resected lymph nodes was 20. In addition, lymphatic drainage is variable according to the type and location of tumors, involving an adapted lymphadenectomy strategy to each situation.

Also in gastric cancer, a complete resection (R0) and adequate lymphadenectomy are predictive factors for healing and long-term survival. Lymphadenectomy is adapted to the type, stage and location of the primary lesion.

In the U.S., the National Cancer Network guidelines recommend a D2 lymphadenectomy or a minimum of 15 lymph nodes (Lymph Node, LN) recovered.However, most international guidelines consider the recovery of only 15 LNs is insufficient. A recent Korean study on more than 25,000 patients showed that the maximum survival advantage is observed by performing a lymphadenectomy with a minimum of 29 LNs recovered. The experience of Western surgeons is much less than that of surgeons in Asia, and it seems obvious that an intraoperative guidance method would be a major support for the decision making in real time and thus remove the current variability related to the level of experience of the surgeon.

In addition, oncology surgery includes in the vast majority of cases a resection of an segment of the digestive tract and requires the restoration of digestive continuity by simple anastomosis and/or by interposition of another intestinal segment.

This stage of the surgical procedure is critical, since any anastomotic leakage is burdened with a risk of complication sometimes lethal. The surgeon's experience, which allows him to evaluate visually the vascularization of the tissue to be anastomosed, is therefore fundamental to prevent the problems.

In esogastric surgery, anastomotic leaks are associated with increased postoperative morbidity, an extended stay in the Intensive Care Unit (ICU), a longer overall hospital stay,reduced quality of life and, in the context of cancer, shortened cancer-specific survival.

Several studies have identified risk factors for anastomotic leakage, such as chemoradiotherapy, surgical technique, smoking, diabetes, and the location of the anastomosis. These factors may compromise the perfusion of the replacement conduit after esophagectomy and gastrectomy and increase the risk of anastomotic leakage. Objective assessment of tissue perfusion could be an excellent tool to identify ischemia of the conduits and thus reduce the incidence of anastomotic leaks. A perfusion compromise of the proximal portion of the gastric conduit, used for the recovery of the digestive continuity after esophagectomy, has been identified as one of the risk factors of digestive fistula.

It is therefore obvious that at the present time, for curative cancer resection or reconstruction after esogastric resection surgery, the outcome of the treatment depends mainly on the surgeon's experience and perception of the surgical field.

Today, the development of specific fluorescence imaging devices enables the surgeons to visualize tumors and vascular and lymphatic structures. This technology is expected to increase the reproducibility of esogastric surgery and its results.

The proposed study is based on the hypothesis that Fluorescence Image Guided Surgery (FIGS) would improve the quality and reproducibility of esophageal and stomach oncology surgery (lymphadenectomy and complete resection), as well as to decrease the risk of anastomotic complications after resective surgery of the esophagus or part or all of the stomach (study of the vascularization).

• Evaluation of the impact of fluorescence guidance on the number of resected lymph nodes in oncological esogastric resections [Time frame: 7 days after operation when pathologic result was reported]
• Evaluation of the impact of fluorescence guidance in intraoperative evaluation of pre-anastomotic tissue perfusion [Time frame: 30 days after operation]