Pancreaticobiliary maljunction (PBM)-associated pancreatitis: a case report and a new treatment strategy proposed for PBM.

Background: Pancreaticobiliary maljunction (PBM) is a rare cause of recurrent pancreatitis. During the past 10 years, treatment protocols for PBM have been progressively improved and revised; however, the latest therapeutic strategies have not been comprehensively summarized in the literatures. Herein, we present a typical case of PBM-related recurrent pancreatitis which highlights the role of PBM in the pathogenesis of pancreatitis and prompts us to revisit and optimize current therapeutic strategies for PBM. Case Description: A 59-year-old female patient was admitted to the hospital with abdominal pain, vomiting and cessation of defecation. The patient had an previous episode of pancreatitis three years ago. Laboratory tests revealed an elevated blood amylase level of 4,418.2 U/L (normal range, 35-135 U/L) and an upper abdominal computed tomography (CT) scan suggested the possibility of pancreatitis. After treatment with dietary restriction, inhibition of gastric acid secretion, inhibition of pancreatic fluid secretion, and rehydration, the patient was relieved of the abdominal pain, and the blood amylase level decreased to 118.8 U/L. However, 6 months after discharge, the patient was readmitted to the hospital because of abdominal pain. Laboratory tests showed that amylase level was >1,200.0 U/L. An upper abdominal CT scan and an upper abdominal dynamic contrast-enhanced magnetic resonance (MR) scan indicated a possibility of autoimmune pancreatitis (AIP). An ultrasonographic endoscopy showed the presence of PBM and the histopathologic findings of the pancreas obtained were the key basis for our diagnosis of PBM, as well as our final exclusion of AIP suggested by upper abdominal CT and upper abdominal dynamic contrast-enhanced magnetic resonance imaging (MRI). Considering the patient's recurrent episodes of PBM-associated pancreatitis, we suggest that the patient could undergo endoscopic retrograde cholangiopancreatography (ERCP) or surgery. However, the patient refused to undergo ERCP and surgery, was discharged from the hospital after experiencing relief of abdominal pain, and continued to be followed up in the outpatient clinic. Conclusions: Based on a case of PBM-related recurrent pancreatitis diagnosed using ultrasonographic endoscopy, we comprehensively reviewed PBM-related literatures. In addition to the classical therapeutic strategy of selecting different surgical procedures based on the morphology of the extrahepatic bile ducts, ERCP, a minimally invasive treatment, has unique advantages in PBM treatment. For symptomatic patients with PBM, ERCP can significantly reduce patient discomfort and facilitate favorable surgical conditions. Furthermore, when the effect of surgery is unclear, or patients do not wish to undergo surgery, ERCP can be used as a complementary or palliative treatment option to provide patients with more therapeutic possibilities. In this study, we propose and describe a new treatment strategy for PBM: combining traditional radical surgical program with ERCP to provide useful experiences and references for future treatment of PBM.