Water exchange-assisted versus carbon dioxide-insufflated single-balloon enteroscopy: a randomized controlled trial

Single-balloon enteroscopy (SBE) is a valuable but difficult modality for the diagnosis and treatment of small-bowel disease. The water exchange method has the advantage of facilitating intubation during colonoscopy. Here, we evaluated the effects of water exchange on procedure-related variables related to SBE.

This randomized controlled trial was conducted in a tertiary-care referral center in China. Patients due for attempted total enteroscopy were randomly allocated to undergo water exchange-assisted (water exchange group) or carbon dioxide-insufflated enteroscopy (CO₂ group). All patients were planned to undergo both anterograde and retrograde procedures. The primary outcome was the total enteroscopy rate. Secondary outcomes included the maximal insertion depth, positive findings, procedural time, and adverse events.

In total, 110 patients were enrolled, with 55 in each group. Baseline characteristics between the two groups were comparable. Total enteroscopy was achieved in 58.2 % (32/55) of the water exchange group and 36.4 % (20/55) of the control group (P = 0.02). The mean (standard deviation) estimated intubation depth was 521.2 (101.4) cm in the water exchange group and 481.6 (95.2) cm in the CO₂ group (P = 0.04). The insertion time was prolonged in the water exchange group compared with the CO₂ group (178.9 [45.1] minutes vs. 154.2 [27.6] minutes; P < 0.001). Endoscopic findings and adverse events were comparable between the two groups.

The water exchange method improved the total enteroscopy rate and increased the intubation depth during SBE. The use of water exchange did not increase the complications of enteroscopy.