Carbon dioxide insufflation improves the intubation depth and total enteroscopy rate in single-balloon enteroscopy: a randomised, controlled, double-blind trial

Objective The total enteroscopy rate of single-balloon enteroscopy (SBE) using air insufflation is not satisfactory, and whether carbon dioxide (CO2) insufflation increases the total enteroscopy rate of SBE is unknown. This randomised controlled trial aimed to determine whether CO2 insufflation facilitates the intubation depth and total enteroscopy rate of SBE. Design A total of 214 eligible patients referred for SBE were randomised to receive either air or CO2 insufflation, and included in the intention-to-test (ITT) analysis. In addition, 199 patients in whom enteroscopy was completed were included in the per-protocol (PP) analysis. Both the patients and endoscopists were blinded, and the intubation depth and total enteroscopy rate were defined as the primary outcomes. Results The CO2 group showed a superiority of intubation in the ITT analysis (oral route: 323.8 +/- 64.2 vs 238.3 +/- 68.6 cm; anal route: 261.6 +/- 74.2 vs 174.7 +/- 62.1 cm, both p<0.001), and the total enteroscopy rate (34.9% vs 17.6%, p=0.006). Similar results were obtained in a PP analysis for both outcomes. In addition, in the PP analysis, the addition of circumference after the procedure was less in the CO2 group (0.8 +/- 0.6 vs 3.3 +/- 1.8 cm, p=0.005) for the oral route. No serious complications were reported. The overall percentage of procedures with significant pathological findings was 52.8%; the rates were 58.5% and 47.2% (p=0.100, ITT analysis) in the CO2 and air groups, respectively. Conclusions CO2 insufflation improves the intubation depth and total enteroscopy rate in SBE with a good safety profile and acceptability compared with that of air, and thus is recommended for clinical utilisation.