Utility of dedicated bougie dilator for a 0.018‐inch guidewire during EUS‐guided biliary drainage: A multi‐center retrospective cohort study

Background During endoscopic ultrasound‐guided biliary drainage (EUS‐BD), a combination of a 19‐gauge needle and a 0.025‐inch guidewire is generally used. However, a 19‐gauge needle has poor maneuverability because of their stiffness and rigidity and might have poor penetrability in non‐dilated bile ducts because of their large bore. In contrast, the application of a 22‐gauge needle is expected to have improved maneuverability. However, only a 0.018‐inch guidewire, which has less supportability, is applicable in the subsequent guidewire selection. This study aimed to evaluate the feasibility and safety of a dedicated bougie dilator for a 0.018‐inch guidewire. Methods From September 2019 to May 2020, 26 patients underwent fistula dilation using the dilator after accessing the bile duct using a 22‐gauge needle and a 0.018‐inch guidewire during EUS‐BD. The success and adverse event rates of EUS‐BD were evaluated. Results Biliary access with a combination of a 22‐gauge needle and a 0.018‐inch guidewire was successful in all with a median bile duct diameter of 5 mm. Dilation of the fistula using the dedicated dilator was also successful in all cases. Subsequently, the dilator was successfully exchanged to an ERCP catheter that allowed for exchange to a 0.025‐inch guidewire, except in one case where the catheter did not cross the fistula and a dilation balloon was inserted for an exchange to a 0.025‐inch guidewire. The technical success rate of the EUS‐BD was 100%. The adverse event rate was 19%. Conclusion The application of the dedicated dilator for a 0.018‐inch guidewire was considered feasible and safe for EUS‐BD. Iwashita and colleagues report successful biliary access in all 26 patients in whom biliary access was attempted using a 22‐gauge fine‐needle aspiration needle and 0.018‐inch guidewire followed by tract dilation with a dedicated bougie dilator during endoscopic ultrasound‐guided biliary drainage. They conclude that this combination is useful for biliary access.