ERCP catheter or dilator? Which is best for fistula dilation following guidewire placement in EUS-guided transhepatic biliary drainage?

Objectives: EUS-guided biliary drainage (EUS-BD) is performed after endoscopic transpapillary biliary drainage fails. Although fistula dilation is one of the most difficult steps of EUS-BD, whether an ultratapered ERCP catheter or a dilator is the best choice for fistula dilation is unclear. In this study, we aimed to identify the optimal device for fistula dilation after guidewire placement.

Materials and methods: Patients who underwent EUS-guided transhepatic biliary drainage between March 2019 and July 2024 were enrolled in this study. The successful fistula dilation rates, patient characteristics, and EUS-BD procedures were compared between patients who underwent fistula dilation with an ultratapered ERCP catheter (Catheter group) and patients who underwent fistula dilation with new dilators (ES dilator or Tornus ES) (Dilator group).

Results: A total of 38 fistula dilation sessions were performed. Among these 38 sessions, 12 involved a catheter, and 26 involved a dilator. The ERCP catheter was specifically intended for use with 0.025 guidewires, and the dilators were specifically intended for use with 0.018 or 0.025 guidewires. Successful fistula dilation was more frequently achieved in the dilator group than in the catheter group (100% (26/26) vs. 50% (6/12), p < 0.01). When the cases were limited to those involving devices specifically intended for use with 0.025 guidewires, the results were similar (dilator group 100% (22/22) vs. catheter group 50% (6/12), p < 0.01). The other outcomes were not significantly different between the two groups.

Conclusions: A dilator is more promising than a tapered ERCP catheter for fistula dilation in EUS-BD.