Impact of instrument channel diameter on therapeutic endoscopic retrograde cholangiography using balloon-assisted enteroscopy

BACKGROUND AND AIM: In therapeutic endoscopic retrograde cholangiography (ERC) using a balloon-assisted enteroscope, each instrument insertion requires a long time, which prolongs the duration of the procedure. We conducted a retrospective single-center study to compare instrument insertability of a double-balloon enteroscope (DBE) with a 2.8-mm instrument channel diameter and a prototype short single-balloon enteroscope (SBE) with a 3.2-mm instrument channel diameter.

METHODS: We used a stop-watch to measure instrument insertion time from the instrument channel port to the tip of the enteroscope when balloon-assisted ERC was done. The instruments were divided into two groups (outer diameter larger or smaller than 2 mm). Lengths from the instrument channel port to the tip of the DBE (EI-530B; FUJIFILM, Tokyo, Japan) and the prototype SBE (SIF-Y0004-V01; Olympus Medical Systems, Tokyo, Japan) were identical (1680 mm). ERC using DBE was carried out in four cases, as was ERC using SBE.

RESULTS: There was a significant time difference (P= 0.001) when using instruments whose outer diameters were >2 mm (53.5 ± 19.0 s in DBE vs 28.4 ± 8.4 s in SBE).

CONCLUSION: The prototype SBE with a 3.2-mm channel demonstrated not only that many types of instrument can be used, but also that the time required to insert instruments may be shorter than that with DBE with a 2.8-mm channel.