Utility of Intraoperative Icg Fluorescence Angiography for Assessing Mucosal Blood Flow in the Gastric Tube

Background The stomach is commonly used for reconstruction in esophagectomy. However, anastomotic leakage is a significant complication, often attributed to blood flow disturbances and tension at the anastomotic region. Recent studies have reported the utility of indocyanine green (ICG) fluorescence imaging in evaluating gastric conduit perfusion, but these evaluations have been limited to the serosal surface. Since gastric conduit creation may cause damage to the submucosal arterial plexus, assessing blood flow only from the serosal surface might not be sufficient. Therefore, we evaluated gastric conduit perfusion from both the serosal and mucosal surfaces. Methods This study included patients diagnosed with esophageal cancer who underwent esophagectomy and gastric conduit reconstruction at our institution since April 1, 2021. Using a laparoscopic camera equipped with an infrared camera, we observed the gastric conduit from both the serosal and mucosal surfaces. We calculated the perfusion time required for contrast enhancement at the tip of the gastric conduit on both surfaces and evaluated differences in enhancement patterns. Postoperatively, endoscopic evaluation was performed on postoperative day 8 to assess blood flow disturbances at the anastomotic region of the gastric conduit, and these findings were compared with intraoperative ICG perfusion assessment. Results Intraoperative ICG fluorescence imaging was used to evaluate gastric conduit perfusion from both the serosal and mucosal surfaces in 23 cases. Among these, two cases showed blood flow impairment (one case of anastomotic leakage and one case of gastric conduit necrosis). In ICG perfusion assessment, one case showed delayed enhancement on both the serosal and mucosal surfaces, while another case showed delayed enhancement only on the mucosal surface. In the case of anastomotic leakage, ICG perfusion imaging of the mucosal surface demonstrated a diffusely white contrast pattern without visible vascular structures, indicative of congestion. Conclusion Our findings suggest that mucosal surface assessment may be more crucial than serosal surface assessment in evaluating gastric conduit perfusion impairment. Further case accumulation and detailed investigations are planned to validate these findings.