Adequate surgical margins following gastrectomy for gastric cancer are required. In addition, a method for accurately detecting tumor location without palpation is needed during robotic surgery. Although several methods have been reported, most of these either lack accuracy or require increased time and effort during intraoperative detection. Herein, we introduce a new method for detecting tumor location using preoperative indocyanine green (ICG) marking and the built-in ICG detection system of the da Vinci Xi Surgical System in robotic gastrectomy to determine appropriate surgical margins.
We used this method to determine the resection line in six patients who underwent robotic distal gastrectomy for clinical T1 gastric cancer. One to three days before surgery, ICG was diluted to 1.0 mg/mL, and 0.1 mL of this diluted ICG solution was endoscopically injected at one site into the submucosal layer of the stomach, 1 cm proximal to the tumor edge. Gastrectomy was performed using the da Vinci Xi surgical platform, equipped with a near-infrared fluorescence imaging system (Firefly®). The diameter of the fluorescent signal during gastrectomy was estimated to be approximately 2 cm.
The resection line was determined on the outer edge of the fluorescent signal, which ensured a tumor-free margin of ≥2 cm. Fluorescent signals were successfully observed in all cases. Moreover, the required 2-cm surgical margin was achieved in all cases. We could successfully determine proximal margins using preoperative ICG injection marking during robotic distal gastrectomy for gastric cancer.