The Learning Curve of Junior Endoscopists in EUS‐Guided Gastroenterostomy With the Wireless Simplified Technique: A Prospective Study

INTRODUCTION: Learning curve of EUS-guided Gastroenterostomy (EUS-GE) has been explored through retrospective studies involving few elite senior endoscopists (SE), with procedural time as the main surrogate outcome. This study aims to evaluate the training of junior endoscopists (JE) approaching the technique and cover clinically relevant patient outcomes. METHODS: From a prospective single-center registry (PROTECT, ClinicalTrials.gov NCT04813055) of EUS-GE for malignant Gastric Outlet Obstruction using the Wireless Simplified [WEST] technique, the learning curve of 3 JE experienced in pancreatobiliary endoscopy was analyzed to identify changing points ("knots") applying linear and spline regression and cumulative sum control chart (CUSUM) on several continuous and dichotomic variables. EUS-GE performed by a SE and different indications were excluded. RESULTS: From a database of 165 EUS-GEs, 100 were performed by one novice endoscopist with prior EUS-GE exposure (JE1) and 35 by two naïve endoscopists (JE2/JE3). On the largest curve (JE1), procedural time and fluoroscopy time did not show any improvement. The use of fluoroscopy (median Air Kerma: 267 Gy [172-506]) showed a significant improvement after 57 interventions (spline regression) and 72 interventions (CUSUM), after which the curve stabilized. The need for supervision/backup of a SE showed a knot after 32 interventions. Technical success (99%), Clinical success (96%), Misdeployments (2%) and AEs (6%) were stable along the learning curve. Conversion from EUS-GE to enteral stenting (11%) tended to decrease over time. Despite naïve endoscopists required significantly higher fluoroscopy time (234 vs. 187 s, p = 0.009) and procedural time (55 vs. 43 min, p = 0.002) than JE1, efficacy and safety outcomes were not different from the general cohort. CONCLUSIONS: From a prospective registry, ≈30 EUS-GE seems required for independent practice, and ≈55-70 to minimize and stabilize the use of fluoroscopy. Endoscopists learning EUS-GE in high-volume institutions using a standardized technique do not compromise high clinical and safety standards.