Pancreatitis after biliary stenting is increased in patients with proximal biliary strictures and prevented or treated by biliary sphincterotomy

Background: Some experts question the need for sphincterotomy prior to biliary stenting as is commonly done; others advocate a biliary sphincterotomy to prevent stent-induced pancreatic ductal obstruction. The aim of the study was to determine the incidence of pancreatitis following biliary stent placement, and to investigate the potential protective role of sphincterotomy. Methods: 83 cases of initial transpapillary biliary stent placement (78 ERCP, 5 percutaneous) during a 1 yr interval were reviewed. The indication for stenting, stricture location (proximal or distal), sphincterotomy status, and incidence and severity of post-ERCP pancreatitis was determined. Proximal biliary strictures were defined as hilar, common hepatic duct, or mid common duct (if cystic duct not patent). Results: Post-procedure pancreatitis according to stricture location and whether a sphincterotomy was done at the time of stent placement is tabulated. Stricture Sphincterotomy Pancreatitis No Stricture N=13 YES 2 0 NO 11 0 Distal Stricture N=46 YES 15 0 NO 31 0 Proximal Stricture N=24 YES 11 0 NO 13 4 (31%) TOTAL N=83 4 (5%) Two cases were severe (1 fatal) and 2 were mild. One of the mild cases initially appeared to be significant but resolved quickly after a needle-knife sphincterotomy within 24hr of stent placement. Conclusions: The risk of pancreatitis after transpapiliary biliary stenting appears increased when the biliary obstruction is proximal. We hypothesize that stenting across a proximal biliary stenosis creates a fulcrum effect which predisposes to stent-induced pancreatic ductal obstruction. This may be prevented or treated by sphincterotomy.