A pilot study to assess mediastinal emphysema after esophageal endoscopic submucosal dissection with carbon dioxide insufflation.

Background and aims : Mediastinal emphysema sometimes develops following esophageal endoscopic submucosal dissection (ESD) without perforation because the esophagus has no serosa. Carbon dioxide (CO 2 ) insufflation during esophageal ESD may reduce the incidence of mediastinal emphysema. The aim of the present study was to compare the incidence and severity of post-ESD mediastinal emphysema in patients receiving CO 2 insufflation vs. standard air insufflation during esophageal ESD. Patients and methods : A total of 27 patients who had undergone esophageal ESD with insufflation of CO 2 between July 2009 and March 2010 were enrolled in this study (CO 2 group). Another 105 patients who had undergone esophageal ESD with air insufflation between March 2004 and May 2009 were included as historical controls (air group). Multi-detector row computed tomography (MDCT) was carried out immediately after ESD. A conventional chest radiograph was taken the next day. Mediastinal emphysema findings on MDCT and radiography were compared between the groups. Results : Mediastinal emphysema detected by chest radiography was 0 % in the CO 2 group vs. 6.6 % in the air group (n.s.). Mediastinal emphysema on MDCT was significantly less frequent in the CO 2 group compared with the air group (30 % vs. 63 %; P  = 0.002). The severity of mediastinal emphysema also tended to be lower in the CO 2 group. Conclusions : Whereas mediastinal emphysema detected by radiography is not so common, MDCT immediately after ESD revealed a certain prevalence of post-ESD mediastinal emphysema. Insufflation of CO 2 rather than air during esophageal ESD significantly reduced postprocedural mediastinal emphysema. CO 2 can be considered as insufflating gas for esophageal ESD.