Since the beginning, our department has been conducting a cross-departmental clinical practice and study for "resection without residual cancer" and "R0 resection" in biliary tract cancer treatment. Consequent to devising diagnostic and surgical methods, the negative margin rate for hilar cholangiocarcinoma reached 86%, median survival time was 47 months, and 50-year overall survival rate of 300 consecutive patients was 42.1%. However, in biliary tract cancer, new treatment strategies are needed for patients with poor prognosis, such as lymph node metastasis. Multidisciplinary treatment is required, such as the combined drug therapy including immunotherapy and surgery, and using genomic information in selecting treatment methods.

Diagnosis of biliary stricture lesions involves distinguishing between benign and malignant conditions and assessing the extent of progression in operable cases. Using dynamic CT for lesions detected through blood tests or abdominal ultrasound, the macroscopic features, progression extent, and degree of vascular infiltration are evaluated. In cases with a high likelihood of cancer, consideration is given to the feasibility of surgical intervention and, if possible, the anticipated surgical approach. Subsequently, endoscopic retrograde cholangiopancreatography (ERCP), along with intraductal ultrasound (IDUS), peroral cholangioscopy (POCS), and/or biliary biopsies and bile cytology, is employed for differentiating between benign and malignant diagnoses and assessing the longitudinal progression of the biliary duct. For challenging cases, such as flat-type strictures, a focus is placed on obtaining biopsies from the narrowed segment, while for nodular or papillary types prone to superficial progression, mapping biopsies are performed at appropriate locations considering the planned surgical approach. Endoscopic diagnostic techniques, including ERCP, carry the risk of adverse events. Therefore, understanding the advantages and disadvantages of various diagnostic methods, such as cytology, biopsy, peroral cholangioscopy, and ultrasound-guided fine-needle aspiration, is crucial for efficiently and reliably reaching a diagnosis.

Radiotherapy (RT) using X-rays and particle therapy (PT) using proton and heavy-ion beams for intrahepatic cholangiocarcinoma (IHCC) and perihilar cholangiocarcinoma (PHCC) are important treatment options as preoperative, postoperative, and definitive therapy. Postoperative adjuvant RT for resectable and definitive PT for unresectable IHCC have shown to be effective. The efficacy of postoperative adjuvant RT using intensity-modulated RT and definitive PT for unresectable PHCC are suggested. For safe RT and PT, spacer implantation has been attempted, and bioabsorbable spacers are currently available. RT and PT should be administered cautiously to avoid bile duct rupture and arterial injury caused by metallic biliary stents. Because RT and PT have minimal invasiveness and a wide range of treatment options, from palliative to radical, these should be considered as treatment options for any patient and tumor condition.

In patients with biliary duct-to-duct reconstruction after liver transplantation, anastomotic stricture (AS) is often present, making endoscopic retrograde cholangiography (ERC) procedure difficult to treat bile duct stones (BDSs). We retrospectively evaluated the ERC results for BDSs in 18 patients with duct-to-duct reconstruction. Thirteen patients (72%) had AS, and the rate of long-time ERC (one hour or more) was significantly higher in patients with intrahepatic stones with AS than in those with common bile duct stones (39% vs. 0%, p=0.008). Moreover, the combination rate of electrohydraulic lithotripsy (EHL) was high at 50% (p=0.025), ERC was particularly difficult in cases of intrahepatic stones with AS. Furthermore, the stone recurrence rate is high in patients with AS (33%), suggesting that AS is a risk for stone formation. In ERC after liver transplantation, it is important not only to remove the stones but also to treat the stricture.

Background: The aim of this study is to find out recurrence risk factors based on imaging findings in patients who underwent elective surgery after conservative treatment for mild acute calculous cholecystitis.

Methods: A total of 80 patients who were hospitalized with mild cholecystitis and received conservative treatment in a year preceding their cholecystectomy between January 2011 and December 2022 at our hospital were included. CT images were used to evaluate five factors: incarcerated gallbladder stone, diameter of the stone in the gallbladder, short axis diameter of the gallbladder, diameter of the bile duct, and length of the cystic duct and divided patients into two groups depending on the presence or absence and severity of each finding. The preoperative recurrence rate was analyzed on each finding retrospectively.

Results: 8 cases developed recurrent before elective surgery. Among the five factors evaluated, cases with a cystic duct length of less than 24.8mm had a significantly higher recurrence rate (p<0.01, Log rank test).

Conclusions: It was suggested that cholecystitis may tend to recur in patients with short cystic duct length after conservative treatment for mild acute calculous cholecystitis.

Precision medicine in biliary tract cancer is advancing rapidly with recent advances incomprehensive genomic panel (CGP). In the severe prognosis of biliary tract cancer, precision medicine is an important therapeutic strategy in addition to conventional cytotoxic anticancer drugs and immune checkpoint inhibitors. In particular, the types and rates of cancer gene aberrations vary by subpopulation, such as intrahepatic cholangiocarcinoma and gallbladder cancer, and there are many target molecules such as FGFR2 fusion gene and HER2 gene amplification that can lead to treatment. It is important to link the CGP to precision medicine in biliary tract cancer, including what to use and when to perform the test.

Recent advances in the analysis of gut microbiota have led to reports of increased or decreased intestinal bacteria in various hepatobiliary diseases. The intestinal tract and liver are connected via the portal vein. Altered intestinal bacterial composition, weakening of the intestinal barrier, bacterial translocation of intestinal bacteria and their metabolites outside the intestinal tract, and activation of host immunity have been reported as one of the mechanisms of pathogenesis and development of biliary diseases via the gut-liver axis, but many aspects remain to be clarified. In this article, we summarize the possible involvement of intestinal bacteria in the pathogenesis of primary sclerosing cholangitis and other biliary diseases reported using clinical samples and animal models, and also refer to the usefulness of intestinal bacteria as diagnostic biomarkers and therapeutic targets in the future.

A 72-year-old female underwent subtotal stomach-preserving pancreaticoduodenectomy for pancreatic head cancer. On the 16th post operative day, fistulography of the drain placed at the pancreaticogastric anastomosis revealed isolated bile leakage from the bile duct of the Spiegel lobe. Drainage was continued, and a 5 Fr balloon catheter was employed to inject 10mg of minocycline on the 27th postoperative day, followed by additional injections of 30mg on the 30th, 33rd, and 36th days postoperative day. No significant adverse effects were observed. Consequently, the bile leakage was relieved and the amount of drainage was reduced, ultimately leading to the removal of the drain. The patient was discharged on the 45th day. It is suggested that injection of minocycline might represent an effective and less invasive treatment option for postoperative severe bile leakage.

A 62-year-old woman who had intrahepatic bile duct dilatation on abdominal ultrasonography was admitted to our hospital for further examination. We found dilatation of the common bile duct and elevated amylase levels in the bile on ERCP, and we found high confluence of pancreatobiliary ducts on MRCP. Since, in addition, abdominal contrast-enhanced CT and abdominal contrast-enhanced MRI showed enhancing solid component within a cystic lesion communicating with the left hepatic duct near the porta hepatis, the patient was diagnosed as high confluence of pancreatobiliary ducts complicated by intraductal papillary neoplasm of the bile duct (IPNB) and we underwent central bisegmentectomy of the liver, caudate lobectomy, and extrahepatic bile duct resection. The pathological diagnosis of IPNB with high grade intraepithelial neoplasia was suggested to be IPNB Type 1 based on the site of origin and findings of mucin producing. Since, to our knowledge, no case of high confluence of pancreatobiliary ducts complicated by IPNB has been reported in the literature, we report our case in detail.

The first case was a female in her 50s. US for surveillance of chronic hepatitis C showed gallbladder wall thickness. MRCP and EUS showed pancreaticobiliary maljunction (PBM) without biliary dilatation. The second case was a female who was the sister of monozygotic twins in first case. She was recommended to be examined by her sister's doctor, and US also showed gallbladder wall thickness. As a result, PBM without biliary dilatation was found. Laparoscopic cholecystectomy was performed in both cases and hyperplastic changes were observed in the resected gallbladder mucosa, but there were no malignancy. There have been few reports of familial occurrence, and our case is the third case of co-occurrence in monozygotic twins. Our case was interesting because it suggests the possibility of familial occurrence. Screening of families with PBM may be remarkable.

The patient is a 42-year-old 6-week pregnant woman. Epigastric pain and jaundice developed 11 days before. A blood test showed elevated hepatobiliary enzymes, and an abdominal ultrasonography revealed choledocholithiasis, and she was referred to our hospital for suspected acute cholangitis. MRCP revealed a 5mm bile duct stone. After thorough discussions with the Department of Obstetrics and Gynecology, the Department of Radiology, and the Department of Pharmacy, we decided to perform ERCP. We successfully inserted the scope into the patient with a minimal amount of drugs and successfully cannulated the bile duct using the pancreatic guidewire method. It was judged dangerous to remove the stone due to the patient's vigorous body movements.

A bile duct stent was inserted after EST, and the procedure was completed quickly. She was discharged on hospital day 3 with no apparent complications. Since the safety of ERCP in pregnant women has not been established, we report it with some review of the literature.

A patient was a 78-year-old woman who underwent laparoscopic cholecystectomy for gallbladder stones and gall bladder polyp. Pathological findings revealed well differentiated mucinous carcinoma of gallbladder invading the subserosal layer. We secondarily conducted liver bed resection and regional lymph node dissection. Postoperative course was uneventful, and she has received postoperative adjuvant chemotherapy with S-1 and gemcitabine for six months. A patient survived without recurrence for more than 5 years after surgery. Mucinous carcinoma of the gallbladder is rare among the histological types of gallbladder carcinoma, and we report our rare case together with a review of domestic cases.

Complications of percutaneous transhepatic biliary drainage (PTBD) include vascular injury occurring during puncture, trans-thoracic puncture, and intra-abdominal bile leakage leading to peritonitis. As a preventive measure against vascular injury, pre-procedural imaging assessment and the use of ultrasound during puncture are recommended. To prevent intra-abdominal bile leakage, strategies include careful selection of the puncture route, thoughtful management of the drainage tube and minimizing the time from dilation with a dilator to tube placement.

Since one of the indications for PTBD is in cases where other biliary drainage methods are difficult, there is an increased relative risk of complications in more challenging cases. Thus, a safe implementation of PTBD, with a thorough understanding of preventive measures against complications, is crucial. Additionally, given the decrease in the number of experienced cases, proper education, and succession of PTBD techniques are important challenges for the future.