Learning curve of EUS-guided gastroenterostomy using the WEST technique: a prospective analysis

Aims The learning curve for EUS-guided Gastroenterostomy (EUS-GE) has been assessed through retrospective studies involving few elite senior endoscopists (SE), using procedural time as the main surrogate outcome. This study aims to evaluate the training course of junior endoscopists (JE) approaching EUS-GE using the WEST technique, considering both technical efficiency and clinically relevant patient outcomes.

Methods From a prospective single-centre registry of EUS-GE (PROTECT, ClinicalTrials.gov NCT04813055) using the Wireless Simplified Technique (WEST), the learning curve of 3 JE, experienced in pancreatobiliary endoscopy (PBE) was analysed to identify inflection points (“knots”), applying adaptive regression and cumulative sum control chart (CUSUM) on several continuous and dichotomous variables. EUS-GE performed by a SE and those on post-surgical anatomy were excluded.

Results From a prospective database of 165 EUS-GE, 100 were performed by a JE with previous EUS-GE training (JE1) and 26 by two naïve JEs. In JE1’s curve, neither procedural nor fluoroscopy time showed any improvement while radiation dose (mean Air Kerma: 392±317 Gy) significantly decreased (F-test p=.0005) after 57 (adaptive regression) and 72 interventions (CUSUM), stabilizing thereafter. The need for supervision/backup from a SE showed a significant knot after 32 procedures (p<.0001). Technical success (100%), clinical success (95.0%), adverse events (AEs; 6.0%) and moderate/severe AEs (4.0%) remained constant through the learning curve, clustered according to the aforementioned knots. Conversion from EUS-GE to enteral stenting was rare (7.2%) and non-significantly decreased over time. Despite requiring significantly higher fluoroscopy time (234 vs. 187 seconds, p=.009) and procedural time (55 vs. 43 minutes, p=.002), naïve endoscopists achieved efficacy and safety outcomes comparable to the remaining cohort.

Conclusions From the analysis of a prospective learning curve, performing≈30 EUS-GE seems required for independent practice, and≈70 to stabilize the fluoroscopy usage. EUS-GE training of naïve PBE endoscopists in high-volume institutions, using a standardized technique, does not compromise clinical and safety standards.

Publication History

Article published online:
27 March 2025