Optimal biliary access point and learning curve for endoscopic ultrasound-guided hepaticogastrostomy with transmural stenting

Background: Although endoscopic ultrasound-guided hepaticogastrostomy (EUS-HGS) with transmural stenting has increased for biliary decompression in patients with an inaccessible papilla, the optimal biliary access point and the learning curve of EUS-HGS have not been studied. We evaluated the optimal biliary access point and learning curve for technically successful EUS-HGS. Methods: 129 consecutive patients (male n = 81, 62.3%; malignant n = 113, 87.6%) who underwent EUS-HGS due to an inaccessible papilla were enrolled. EUS finding and procedure times according to each needle puncture attempt in EUS-HGS were prospectively measured. Learning curves of EUS-HGS were calculated for two main outcome measurements (procedure time and adverse events) by using the moving average method and cumulative sum (CUSUM) analysis, respectively. Results: A total of 174 EUS-HGS attempts were performed in 129 patients. The mean number of needle punctures was 1.35 +/- 0.57. Using the logistic regression model, bile duct diameter of the puncture site <= 5 mm [odds ratio (OR) 3.7, 95% confidence interval (CI): 1.71-8.1, p < 0.01] and hepatic portion length [linear distance from the mural wall to the punctured bile duct wall on EUS; mean hepatic portion length was 27 mm (range 10-47 mm)] > 3 cm (OR 5.7, 95% CI: 2.7-12, p < 0.01) were associated with low technical success. Procedure time and adverse events were shorter after 24 cases, and stabilized at 33 cases of EUS-HGS, respectively. Conclusions: Our data suggest that a bile duct diameter > 5 mm and hepatic portion length 1 cm to 3 cm on EUS may be suitable for successful EUS-HGS. In our learning curve analysis, over 33 cases might be required to achieve the plateau phase for successful EUS-HGS.