Pancreatic Stent-Induced Ductal Injury

Abstract

Purpose: Pancreatic duct (PD) stent placement is increasingly performed for prevention of post-ERCP pancreatitis in patients at high risk. PD stents can result in injury especially in normal ducts, but the clinical significance and outcomes of subsequent endoscopic therapy are not known. Methods: Patients included all those referred from outside facilities to a single pancreaticobiliary center for management of stent-induced PD injury over 3 years. All pts had initially normal PD diameter without evidence of chronic pancreatitis, and all PD stents were placed for prevention of post-ERCP pancreatitis. Results: 7 pts were referred for symptomatic PD stent-induced duct injury. At initial outside ERCP, all had small caliber (<or = 3 mm) PD with normal PD anatomy (N = 5) or pancreas divisum (N = 2). Indication for initial ERCP with prophylactic PD stent placement was suspected SOD with empirical biliary ± pancreatic sphincterotomy without SO manometry (N = 5), or minor papillotomy for pancreas divisum with acute recurrent pancreatitis (N = 1) or marginally elevated lipase (N = 1). All had conventional polyethylene 5 F (N = 6) or 7 F (N = 1) stents <4 cm in length in place for <2 weeks, except one pt who was lost to follow up with stent in place for one year. At presentation at a mean interval of 19 months after 1st ERCP, all pts had recurrent abdominal pain requiring hospitalization; of these 5/7 (71%) had acute recurrent pancreatitis, and 3/7 (43%) were on daily narcotics. By secretin MRCP/EUS/ERCP, all had a PD stricture within 2 cm of major or minor papilla and 5/7 (71%) upstream PD dilation (mean 4.6 mm, [3 mm–8.2 mm]). 2/5 (40%) pts undergoing EUS had new parenchymal changes suggestive of chronic pancreatitis. All patients were treated with pancreatic sphincterotomy (if not done already), balloon dilation of stricture, and placement of multiple 3–5 F soft polymer pancreatic stents depending on duct diameter; all but one required multiple (2–11) ERCPs for therapy. All had improvement or resolution of pancreatic strictures and recurrent pancreatitis. 4/7 had sustained clinical response with resolution of pain, 1/7 fair response with repeated ERCPs, and 2/7 poor response, with referral for total pancreatectomy with auto-islet transplantation. Conclusion: PD stent-induced ductal injury with significant clinical consequences can occur after a relatively brief interval of stenting using conventional polyethylene 5 F stents. Endoscopic therapy is moderately effective but some patients develop irreversible damage. Further investigation is required to determine prevalence and risk factors for stent-induced injury and to improve configuration and material of stents.