Learning curve for Endoscopic Ultrasound guided Antegrade Biliary Stent placement in Malignant Biliary Obstruction: Retrospective analysis of a large cohort from India

Aims Endoscopic Ultrasound antegrade stent placement (EUS-AG) is a technically challenging transpapillary technique of biliary drainage which has previously received lesser attention^1,2. EUS-AG is known to be associated with challenges in various steps from puncture of appropriate intrahepatic bile duct, guide-wire passage across the hilum and then across stricture, and subsequently transpapillary stent placement. We aimed to identify the learning curve for EUS-AG with respect to proficiency in terms of time, technical success and adverse events [1] [2].

Methods Retrospective review of patients who underwent EUS-AG at a referral cancer center was done from January 2021 till July 2024 performed by a single operator. Baseline demographics in form of age, sex, primary malignancy, intent of stent placement, reason for EUS-AG, level of block and size of prestenotic bile duct, technical success (successful transpapillary metal stent placement), procedure time and adverse events of procedure (as per ASGE Lexicon). Primary outcome was learning curve to achieve proficiency in terms of time of procedure, rate of technical success and adverse events. Linear, quadratic and cubic regression models were used to determine learning curve.

Results One-hundred and fifty-one patients were included in the analysis (Mean age 54.15 years, 56.3% Males, 27.8% cholangitis, Distal block 64.2%). EUS-AG was done predominantly in view of inaccessible papilla secondary to gastroduodenal stenosis (79.5%). Technical success was achieved in 138 (91.4%) patients. Mean procedure time was 46.15+24.35 mins. The cubic regression model best represents the learning curve (R² 0.99) indicating plateauting after 45 procedures suggesting proficiency at this level. A secondary decrease in procedure time is seen after 110 procedures suggesting that the operator has achieved a higher level of mastery. The regression model also suggests that learning curve plateaus after 60 procedures for technical success and after 69 procedures for adverse events, suggesting higher proficiency with higher technical success and lower adverse events with experience.

Conclusions The cubic regression analysis is representative of the learning curve for EUS-AG with time proficiency achieved after 45 procedures and mastery achieved after 110 cases. Technical success and adverse events stabilize after 60 and 69 procedures suggesting high proficiency with increasing number of procedures.

Publication History

Article published online:
27 March 2025

• References

• 1 Giri S, Mohan BP, Jearth V, Kale A, Angadi S, Afzalpurkar S. et al. Adverse events with EUS-guided biliary drainage: a systematic review and meta-analysis. Gastrointestinal Endoscopy 2023; 98 (04): 515-523.e18
• 2 Sundaram S, Mane K, Patil P, Rathod R, Jain AK, Tyagi U. et al. Endoscopic Ultrasound-Guided Antegrade Stent Placement in Patients with Failed ERCP as a Modality of Preoperative and Palliative Biliary Drainage. Dig Dis Sci 2023; 68 (04): 1551-8