Risk Factors for Pancreatitis and Cholecystitis after Endoscopic Biliary Stenting in Patients with Malignant Extrahepatic Bile Duct Obstruction

Background/Aims: For the treatment of malignant binary obstruction, endoscopic retrograde biliary drainage (ERBD) has been widely accepted as a standard procedure. However, post-ERBD complications can affect the lives of patients. The purpose of this study was to identify the predictive factors for these complications, including the patient's status, cancer status, and stent type. Methods: This was a retrospective analysis conducted in a single tertiary hospital from January 2007 to July 2017. The following variables were evaluate& sex, age body mass index, cancer type, history of pancreatitis, gallbladder stone, previous biliary stenting, pre-cut papillotomy, stent type, contrast injection into the pancreatic duct or gallbladder, cystic duct invasion by the tumor, and occlusion of the cystic duct orifice by a metal stent. Results: Multivariate analysis showed that contrast injection into the pancreatic duct was a risk factor for pancreatitis. Patients with a history of bile drainage showed a lower risk of pancreatitis. For cholecystitis, the analysis revealed contrast injection into the gallbladder and cystic duct invasion by the tumor as important predictive factors. Metal stents showed a greater risk of post-procedure pancreatitis than plastic stents, but did not affect the incidence of cholecystitis. Conclusions: Considering that contrast injection is the most important factor for both complications, a careful approach by the physician is essential in preventing the occurrence of any complications. Further, choosing the type of stent is an important factor for patients at a risk of post-procedure pancreatitis.