Endoscopic transpapillary gallbladder drainage has become a popular drainage method for acute cholecystitis (AC), but there are few reports on its use as a bridge to surgery (BTS). We report on the efficacy and safety of 20 AC patients who underwent endoscopic gallbladder stenting (EGBS) as BTS. The technical EGBS success rate was 100% (20/20). Procedure-related complications (mild acute pancreatitis) occurred in 1 patient, who improved rapidly with conservative treatment. Preoperative stent issues were seen in 1 patient who underwent stent exchange endoscopically followed by cholecystectomy. EGBS as BTS is considered to be effective and safe for AC patients undergoing planned cholecystectomy.

We compared the clinical features and long-term prognosis of 159 patients with type 1 autoimmune pancreatitis (AIP) with and without bile duct involvement. Eighty-nine (56%) patients had bile duct involvement. Forty-nine patients (30.8%) had relapse, with a significantly higher cumulative relapse rate in patients with stenosis or wall thickening upstream of the intrapancreatic bile duct (3 years: 24% vs. 37.1%, P<0.001). A significantly higher rate of two or more relapses (5.1% vs. 19.5%, P=0.01) was also found in these patients. Two patients with stenosis/dilatation up to the intrahepatic bile ducts became steroid-dependent and were treated with azathioprine. Type 1 AIP patients with stenosis and wall thickening upstream of the intrapancreatic bile ducts have a high relapse rate and may become steroid-dependent, especially in cases with stenosis and dilation extending into the intrahepatic bile ducts.

Peroral cholangioscopy is used for the diagnosis of biliary strictures and treatment of biliary stones. Recent advances in cholangioscope technology have improved the accuracy of diagnosing biliary neoplasms and its lateral extent. A new cholangioscopy system with a 4-way tip deflection system and a dedicated water irrigation channel has enabled easy lithotripsy with clear views, resulting in improved success rates and shortened procedure times. This newly developed system can be applied to a wide range of biliary interventions and trouble shootings.

Sphincter of Oddi (SO) regulate bile flow and prevent reflex of duodenal content to pancreato-biliary duct system. SO changes its behavior dramatically. In postprandial state, SO relaxes synchronously with gallbladder contractions, and facilitate bile output. Conversely in fasting state, SO assist gallbladder filling by its basal pressure and phasic contractions. Furthermore, SO allows small volume of bile flow out cyclically into duodenum, then maintain entero-hepatic circulation of bile. Abnormal SO motor function cause SO dysfunction (SOD) and gallstone recurrence. SO manometry is still gold standard for diagnosis of SOD, however, new safer and reliable diagnostic method is desired. Balloon dilatation of SO and laparoscopic explorations of common bile duct are promising treatment for preserving SO motor function. Some problems such as high risk of pancreatitis and technical difficulties should be solved. SO motor physiology is largely elucidated in over 130 years since Rugelo Oddi discovered SO, however, fundamental question such as "pump or resistor issue" is still controversial.

We experienced three cases of synchronous multiple gallbladder cancer.

Case 1; an 81-year-old woman. During follow-up for gallstones, a gallbladder tumor was detected, and laparoscopic cholecystectomy was performed. Two lesions in the resected specimen were adenocarcinoma. Gallbladder bed resection and lymph node dissection were performed as additional resections. T2aN0M0 Stage IIA was diagnosed.

Case 2; a 76-year-old man. A gallbladder tumor was detected by abdominal examination, and surgery was performed. There was infiltration in the transverse colon and duodenum. Gallbladder bed resection, subtotal stomach-preserving pancreaticoduodenectomy, and partial transverse colectomy were performed. Two lesions in the resected specimen were adenocarcinoma and T3aN0M0 stage IIIA was diagnosed.

Case 3; a 92-year-old woman. A detailed abdominal examination revealed a gallbladder tumor, and cholecystectomy was performed because of advanced age. The resected specimen revealed four lesions; one was a combination of adenocarcinoma and neuroendocrine carcinoma (NEC) and three were adenocarcinoma, and T2N1M0 stage IIIB was diagnosed.

Multiple gallbladder carcinomas, especially those with NEC, are extremely rare.

A woman in her 70s presented to our hospital with loss of appetite and right hypochondrial pain. Blood test results showed a high eosinophil count, a high serum IgG4, and elevated serum levels of hepatobiliary enzymes. Transabdominal, endoscopic, and intraductal ultrasonography revealed diffuse and homogeneous thickening of the common bile duct wall. Contrast-enhanced computed tomography revealed perihilar bile duct stenosis and bilateral supraclavicular, mediastinal, pulmonary hilar, as well as hepatoduodenal ligament, and abdominal para-aortic lymphadenopathy. Based on histopathological evaluation of a bile duct biopsy and a mediastinal lymph node specimen obtained via endoscopic ultrasound-guided fine-needle aspiration, we diagnosed bile duct lesion as eosinophilic cholangiopathy, and thought of the reason of systemic lymphadenopathy as IgG4-related lymphadenopathy. Prednisolone (30mg/day) therapy was initiated, both of them improved.

A 48-year-old woman with a chief complaint of postprandial epigastralgia was referred to our hospital. She had been diagnosed with primary biliary cholangitis (PBC) at age 37. We suspected organic common bile duct obstruction by gallstones because of being elevated hepatobiliary enzymes. No abnormalities were found in the computed tomography (CT), magnetic resonance cholangiopancreatography, abdominal ultrasonography, esophagogastroduodenoscopy, and endoscopic ultrasonography. Gallstones and sludge were absent in the gallbladder and biliary tract. The cholescintigraphy showed decreased gallbladder ejection and delayed excretion of drugs from the liver. We concluded functional gallbladder disorder with intrahepatic cholestasis due to PBC. To the best of our knowledge, this is the first report of functional gallbladder disorder with concomitant exacerbations of PBC diagnosed by cholescintigraphy.

A man in 60s was referred to our hospital presenting with jaundice. Contrast-enhanced CT revealed contrast effects suggestive of a neoplastic lesion in the hilar bile duct. ERCP showed stenosis of the hilar bile duct, leading to a cytological staging of Class V. The patient was diagnosed with hilar cholangiocarcinoma (cT4aN0M0, cStage IVA) and gemcitabine/cisplatin/S-1 (GCS) therapy was commenced. The tumor reduced on CT performed after 4 courses of chemotherapy. However, adenocarcinoma was detected on biopsy after 14 courses. After 17 courses, Grade 4 neutropenia/thrombocytopenia appeared and the treatment was switched to S-1 monotherapy. Cholangioscopic bile duct biopsy at 28 months after GCS therapy was negative. Chemotherapy was discontinued four years nine months ago, with maintenance of complete response till the present time.

A 44-year-old male patient was suspected to have gallbladder cancer during the follow-up for primary sclerosing cholangitis (PSC) and ulcerative colitis. He underwent gallbladder bed resection and lymphadenectomy. Pathological findings showed a well-differentiated adenocarcinoma with serosal invasion, and biliary intraepithelial neoplasia (BilIN) on the background mucosal surface. It has been reported that the mechanism of biliary carcinogenesis is the accumulation of oxidative stress due to persistent cholangitis and hepatitis, which leads to DNA damage and biliary carcinogenesis. The involvement of BilIN in biliary carcinogenesis in PSC has been suggested. In the present case, BilIN-1 to 3 lesion was observed in the gallbladder mucosa of the noncancerous area. Therefore, a mechanism of BilIN-mediated multi-step carcinogenesis from chronic inflammation caused by PSC was suspected.

IgG4-related sclerosing cholangitis (IgG4-SC) is a sclerosing cholangitis characterized by elevation of serum IgG4 levels, dense infiltration of IgG4-positive plasma cells and lymphocytes, with fibrosis and obliterative phlebitis in the bile duct wall, and it is currently recognized as a biliary manifestation of a IgG4-related disease. Cholangiocarcinoma, primary sclerosing cholangitis, and pancreatic cancer are important mimickers because cholangiograms of IgG4-SC are similar to those of these mimickers. The diagnosis of IgG4-SC is based on clinical diagnostic criteria of IgG4-SC 2020. Cholangiographic classification and the association with AIP are important for the precise diagnosis of IgG4-SC in clinical diagnostic criteria of IgG4-SC 2020. Serum IgG4 level, endoscopic retrograde cholangiopancreatography, biliary intraductal ultrasonography, endoscopic bile duct biopsy, and IgG4-RD as other organ involvement are useful modalities and findings in the differential diagnosis of IgG4-SC. Isolated type IgG4-SC without AIP is sometimes difficult to discriminate from other mimickers. The clinical and radiological features of IgG4-SC are resolved by steroid therapy and the long-term prognosis is good.