Indocyanine green was injected under endoscope within 24 hours before operation. Four points(0.5ml/point,1.25mg/ml) were evenly injected in four quadrants at the edge of the tumor. The injection method was direct submucosal injection and 0.5ml saline + 0.5ml indocyanine green solution + 0.5ml saline (sandwich method). The imaging effect was evaluated by indocyanine green fluorescence imaging system during the operation. The effect was divided into grade0 and Grade1. Grade1: The imaging of the tumor and the corresponding lymphatic drainage area in the injection area both were ideal. Grade 0: not up to grade 1, classified into tumor body and drainage area without imaging, only tumor body imaging, and even though tumor body and regional lymph drainage area imaging, the contrast agent in the gastric wall was too diffuse or even overflowing, which seriously interfered with the observation of lymph drainage area imaging.

The imaging effect was evaluated by indocyanine green fluorescence imaging system during the operation. The effect was divided into grade0 and Grade1. Grade1: The imaging of the tumor and the corresponding lymphatic drainage area in the injection area both were ideal. Grade 0: not up to grade 1, classified into tumor body and drainage area without imaging, only tumor body imaging, and even though tumor body and regional lymph drainage area imaging, the contrast agent in the gastric wall was too diffuse or even overflowing, which seriously interfered with the observation of lymph drainage area imaging.