title: Sequential algorithm analysis to facilitate selective biliary access for difficult biliary cannulation in ERCP: a prospective clinical study.
abstract: BACKGROUND
  Numerous clinical trials to improve the success rate of biliary access in difficult biliary cannulation (DBC) during ERCP have been reported. However, standard guidelines or sequential protocol analysis according to different methods are limited in place. We planned to investigate a sequential protocol to facilitate selective biliary access for DBC during ERCP.
  
  
  METHODS
  This prospective clinical study enrolled 711 patients with naïve papillae at a tertiary referral center. If wire-guided cannulation was deemed to have failed due to the DBC criteria, then according to the cannulation algorithm early precut fistulotomy (EPF; cannulation time > 5 min, papillary contacts > 5 times, or hook-nose-shaped papilla), double-guidewire cannulation (DGC; unintentional pancreatic duct cannulation ≥ 3 times), and precut after placement of a pancreatic stent (PPS; if DGC was difficult or failed) were performed sequentially. The main outcome measurements were the technical success, procedure outcomes, and complications.
  
  
  RESULTS
  Initially, a total of 140 (19.7%) patients with DBC underwent EPF (n = 71) and DGC (n = 69). Then, in DGC group 36 patients switched to PPS due to difficulty criteria. The successful biliary cannulation rate was 97.1% (136/140; 94.4% [67/71] with EPF, 47.8% [33/69] with DGC, and 100% [36/36] with PPS; P < 0.001). The mean successful cannulation time (standard deviation) was 559.4 (412.8) seconds in EPF, 314.8 (65.2) seconds in DGC, and 706.0 (469.4) seconds in PPS (P < 0.05). The DGC group had a relatively low successful cannulation rate (47.8%) but had a shorter cannulation time compared to the other groups due to early switching to the PPS method in difficult or failed DGC. Post-ERCP pancreatitis developed in 14 (10%) patients (9 mild, 1 moderate), which did not differ significantly among the groups (P = 0.870) or compared with the conventional group (P = 0.125).
  
  
  CONCLUSIONS
  Based on the sequential protocol analysis, EPF, DGC, and PPS may be safe and feasible for DBC. The use of EPF in selected DBC criteria, DGC in unintentional pancreatic duct cannulations, and PPS in failed or difficult DGC may facilitate successful biliary cannulation.
authors: Division of Gastroenterology, Department of Internal Medicine, Soonchunhyang University School of Medicine, Cheonan Hospital, 23-20 Bongmyung-dong, Cheonan, South Korea. thlee9@schmc.ac.kr.
authors: Tae Hoon
authors: TH
authors: Lee
authors: Soon Oh
authors: SO
authors: Hwang
authors: Hyun Jong
authors: HJ
authors: Choi
authors: Yunho
authors: Y
authors: Jung
authors: Sang Woo
authors: SW
authors: Cha
authors: Il-Kwun
authors: IK
authors: Chung
authors: Jong Ho
authors: JH
authors: Moon
authors: Young Deok
authors: YD
authors: Cho
authors: Sang-Heum
authors: SH
authors: Park
authors: Sun-Joo
authors: SJ
authors: Kim
mesh_terms: D000368:Aged; D000465:Algorithms; D002404:Catheterization / Q000379:methods*; D002760:Cholangiopancreatography, Endoscopic Retrograde / Q000009:adverse effects / Q000379:methods*; D003135:Common Bile Duct; D003661:Decision Support Techniques; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010183:Pancreatic Ducts; D010195:Pancreatitis / Q000209:etiology; D011446:Prospective Studies; D015607:Stents; D013997:Time Factors