Quantitative examinations evaluating the effects of CO2 insufflation on residual gas in the gastrointestinal tract following colorectal endoscopic submucosal dissection (ESD) are lacking. The present study aimed to assess whether CO2 insufflation could decrease the amount of residual gas in the gastrointestinal tract following ESD in patients with colorectal neoplasms. Computed tomography (CT) was used to objectively examine whether CO2 insufflation during colorectal ESD reduced residual gas levels in the gastrointestinal tract following ESD. A total of 83 patients who underwent colorectal ESD between January and December 2009 at Gifu University Hospital (Gifu, Japan) were enrolled. Following exclusion of 17 patients with chronic pulmonary dysfunction, 66 patients were randomized into a CO2 insufflation group (n=34) and an air insufflation group (n=32). The level of residual gas and the presence of transmural and free-air leaks following ESD were evaluated in both groups using CT. Transcutaneous CO2 tension (PtcCO2) and ESD-related complications were also compared between the groups. CT measurements of the major and minor axes of the cecal lumen, and of the terminal ileum diameter, indicated the level of residual gas following ESD to be significantly reduced in the CO2 insufflation group compared with the air insufflation group (P<0.001). Neither the incidences of ESD-related complications, including post-procedure hemorrhage and air leak, nor the abnormalities in vital signs differed between the groups. No significant between-group differences were identified in the baseline and peak PtcCO2 levels during ESD or in the median PtcCO2 following ESD. In conclusion, CO2 insufflation during colorectal ESD was effective in reducing residual gas in the gastrointestinal tract following ESD.
Keywords: carbon dioxide; colorectal endoscopic submucosal dissection; computed tomography; insufflation; residual gas.