摘要： Background: Indocyanine green (ICG) ?uorescence imaging has been used to assess the blood perfusion of the gastrointestinal tract in surgery. Especially, it was used to determine the best anastomotic site. However, in previous studies, ICG ?uorescence was judged subjectively based on the visual appearance. This study evaluated the usefulness of our novel method to quantitatively assess the blood perfusion of the gastric conduit in esophagectomy based on ICG ?uorescence. Materials and methods: Twenty patients who underwent esophagectomy with gastric conduit reconstruction were prospectively investigated. Using a camera in contact with the surface of the stomach, ICG images were quantitatively evaluated using “ROIs”, a software program that quanti?ed the ?uorescence intensity and created a time-?uorescence intensity curve to assess the blood perfusion three times intraoperatively. Results: No postoperative esophago-gastrostomy leakage developed. However, after preparing the gastric conduit and just before anastomosis, the maximum increase in ?uorescence intensity (FImax) signi?cantly decreased (48.8 (cid:1) 26.0 and 31.5 (cid:1) 14.9 versus 84.9 (cid:1) 28.2; P < 0.001 and P < 0.001, respectively), and the time to reach FImax was signi?cantly extended (60 (cid:1) 35.4 and 58.3 (cid:1) 34.9 versus 18.9 (cid:1) 6.5; P < 0.001 and P < 0.002, respectively), in comparison to the control value. Just before anastomosis, 18 cases (90%) showed an identical pattern characterized by an obtuse and low arterial in?ow peak and a slow rise of ?uorescence intensity over time, indicating a decreased blood ?ow. Conclusions: The quantitative analysis of ICG ?uorescence imaging could objectively prove a decrease in blood perfusiondwhich could not be determined macroscopicallydin the gastric conduit before esophageal reconstruction. The results from the present and further studies may indicate its clinical value.