Novel Oxygen Saturation Imaging to Evaluate Gastric Conduit Perfusion During Esophagectomy

Background Poor gastric conduit perfusion by indocyanine green (ICG) fluorescence angiography has been shown to be a risk factor associated with post esophagectomy anastomotic leak. A novel oxygen saturation imaging (OSI) can create a color-coded tissue oxygen saturation (StO2) map both endoscopically and laparoscopically. OSI can be used repeatedly with a snapshot assessment of perfusion, compared to the ICG angiography which measures a temporal uptake of dye. We evaluated the use of this novel OSI approach as an alternative to ICG dye assessment to measure gastric conduit perfusion during gastric mobilization and after conduit preparation. Methods Intraoperative perfusion assessment data was prospectively collected for fifteen patients undergoing a minimally invasive robotic transhiatal esophagectomy at a single, high-volume, quaternary hospital. OSI data were obtained at 4 distinct time points including baseline perfusion (laparoscopically and endoscopically), ligation of short gastric arteries (laparoscopically), ligation of the left gastric artery (laparoscopically and endoscopically), and during gastric conduit preparation (laparoscopically). Changes in perfusion during stepwise ligation were noted and final gastric conduit preparation was compared to the Standard ICG dye perfusion assessment. Results OSI imaging using was successfully captured for all fifteen patients at each of the stepwise timing of decreased perfusion. Laparoscopic OSI demonstrated reduction in perfusion for each step of ligation (Fig-Panel A) (p = 0.007). Conduit assessment by ICG dye (Fig-B) correlated roughly with OSI (Fig- C) in all fifteen patients in terms of gradient of perfusion and decreased perfusion at the gastric tip with one representative case shown in the Figure. Endoscopic mucosal perfusion was significantly higher than laparoscopic serosal perfusion after vascular ligation (Fig-D) (p < 0.005). Conclusion OSI can measure gastric conduit perfusion both qualitatively and quantitatively. OSI may be used without delay between steps and may be an alternative to ICG dye perfusion to measure gastric conduit perfusion. Mucosal perfusion does not appear to change as much as serosal perfusion during arterial ligation. Additional study is required to understand the impact of OSI and its clinical implications.