title: Optimal biliary access point and learning curve for endoscopic ultrasound-guided hepaticogastrostomy with transmural stenting.
abstract: 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 (malen= 81, 62.3%; malignantn= 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.
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.
authors.forename: Dongwook
authors.initials: D
authors.lastname: Oh
authors.affiliation: Associate Professor of Medicine, University of Ulsan College of Medicine, Asan Medical Center, 88-Olympic-Ro 43-Gil, Songpa-gu, Seoul 05505, Korea.
authors.forename: Do Hyun
authors.initials: DH
authors.lastname: Park
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.
authors.forename: Tae Jun
authors.initials: TJ
authors.lastname: Song
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.
authors.forename: Sang Soo
authors.initials: SS
authors.lastname: Lee
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.
authors.forename: Dong-Wan
authors.initials: DW
authors.lastname: Seo
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.
authors.forename: Sung Koo
authors.initials: SK
authors.lastname: Lee
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.
authors.forename: Myung-Hwan
authors.initials: MH
authors.lastname: Kim
keywords: biliary obstruction; endoscopic ultrasound; endoscopic ultrasound-guided biliary drainage; learning curve