CO2 insufflation during single-balloon enteroscopy: a multicenter randomized controlled trial.

Background and study aims: Carbon dioxide (CO2) insufflation has previously been shown to have advantages over air insufflation in terms of procedure-related pain and oral insertion depth during double-balloon enteroscopy. The aim of this prospective study was to evaluate the performance of CO2 vs. air insufflation during single-balloon enteroscopy. Patients and methods: This study was a randomized European multicenter trial (ClinicalTrials.gov: NCT01524055). Patients and endoscopists were blinded to the type of insufflation gas used. Patient discomfort during and after the procedure was scored using a visual analog scale. Results: A total of 107 patients were enrolled in the study (52 in the CO2 group and 55 in the air group). Patient characteristics were comparable in both groups. The mean (SD) oral intubation depth was not significantly deeper in the CO2 group vs. the air group (254 +/- 80 vs. 238 +/- 55cm; P=0.726). However, in patients with previous abdominal surgery, oral intubation depth was significantly higher in the CO2 group compared with the air group (258 +/- 84 vs. 192 +/- 42 cm; P<0.05). In patients undergoing SBE via the anal approach, CO2 showed no significant difference in intubation depth compared with air insufflation (86 +/- 67 vs. 110 +/- 68 cm; P=0.155). The diagnostic yield was comparable (CO2 67%; air 73%). Procedure times, dosage of sedation, and therapeutic interventions did not differ between the two groups. Patients in the CO2 group reported less pain than those in the air group. Conclusions: This study demonstrated an advantage of using CO2 insufflation during single-balloon enteroscopy in patients with a history of previous abdominal surgery. Overall, single-balloon enteroscopy was a well-tolerated procedure that may benefit from the use of CO2 insufflation to reduce post-procedural pain.