Patients with malignant biliary obstruction (MBO) are often treated with endoscopic retrograde cholangiopancreatography (ERCP) combined with biliary stent placement for tumor progression. However, certain patients die within 30 days after the procedure, increasing healthcare resource consumption and patient burden. Therefore, the development of early mortality prediction models is important for optimizing treatment decisions. The present study retrospectively analyzed the clinical data of 285 patients with MBO, including demographic information, laboratory indicators and tumor-related factors. Logistic regression and artificial neural network (ANN) models were used to construct a prediction tool, and the model performance was evaluated using area under the curve (AUC), accuracy, sensitivity and specificity. The logistic regression model, which identified the cancer antigen 19-9 (CA19-9) level and a history of previous ERCP surgery as independent risk factors, had an AUC of 0.727 and an accuracy of 65.0%. The ANN model, which combined five variables, namely CA19-9, history of previous ERCP surgery, neutrophil-lymphocyte ratio (NLR), liver metastasis and carcinoembryonic antigen, demonstrated that NLR was the most weighted predictor. Furthermore, the ANN model had an AUC of 0.813, an accuracy of 88.2% and a specificity that was markedly higher than that of the logistic regression model (95.5 vs. 83.3%). However, the ANN model was revealed to be slightly less sensitive compared with the logistic regression model (61.1 vs. 61.2%). In conclusion, compared with logistic regression, the ANN model had a greater performance level in terms of predictive power and specificity, and is suitable for capturing complex non-linear relationships. However, its complexity and risk of overfitting need to be further optimized. The present study provides a new tool for the accurate prediction of the risk of early death after ERCP in patients with MBO, which could help improve individualized treatment strategies.

Cholangiocarcinoma (CCA) is an adenocarcinoma originating from the epithelial cells of the bile ducts/hepatocytes or peribiliary glands. There are three types of cholangiocarcinoma: intrahepatic, perihilar and distal. CCA represents approximately 3% of the gastrointestinal malignancies. The incidence of CCA is higher in regions of the Eastern world compared to the Western countries. There are multiple risk factors associated with cholangiocarcinoma such as liver fluke, primary sclerosing cholangitis, chronic hepatitis B, liver cirrhosis and non-alcoholic fatty liver disease. Endoscopy plays an important role in the diagnosis and management of cholangiocarcinoma. The main endoscopic methods used for diagnosis, biliary drainage and delivering intrabiliary local therapies are endoscopic retrograde cholangiopancreatography and endoscopic ultrasound. The purpose of this review is to analyze the current data found in literature about cholangiocarcinoma, with a focus on the actual diagnostic tools and endoscopic management options.

Distal cholangiocarcinoma (dCCA) is a rare malignancy arising from the epithelial cells of the distal biliary tract and has a poor prognosis. dCCA is often clinically silent and patients commonly present with locally advanced and/or distant disease. For patients identified with early stage, resectable disease, surgical resection with negative margins remains the only curative treatment strategy available. However, despite appropriate treatment and diligent surveillance, risk of recurrence remains high with nearly 50% of patients experiencing recurrence at 5 years subsequent to surgical resection; therefore, it is prudent to continue to optimize neoadjuvant and adjuvant therapies in order to reduce the risk of recurrence and improve overall survival. In this review, we discuss the clinical presentation, workup and surgical treatment of dCCA.

Biliary drainage, either by the stent-in-stent (SIS) or side-by-side (SBS) technique, is often required when treating a malignant hilar biliary obstruction (MHBO). Both methods differ from each other and have distinct advantages.

To compare both techniques regarding their efficacy and safety in achieving drainage of MHBO.

A comprehensive search of multiple electronic databases (MEDLINE, Embase, LILACS, BIREME, Cochrane) was conducted and grey literature from their inception until December 2020 with no restrictions regarding the year of publication or language, since there was at least an abstract in English. The included studies compared SIS and SBS techniques through endoscopic retrograde cholangiopancreatography. Outcomes analyzed included technical and clinical success, early and late adverse events (AEs), stent patency, reintervention, and procedure-related mortality.

Four cohort studies and one randomized controlled trial evaluating a total of 250 patients (127 in the SIS group and 123 in the SBS group) were included in this study. There were no statistically significant differences between the two groups concerning the evaluated outcomes, except for stent patency, which was higher in the SIS compared with the SBS technique [mean difference (d) = 33.31; 95% confidence interval: 9.73 to 56.90, I 2 = 45%, P = 0.006].

The SIS method showed superior stent patency when compared to SBS for achieving bilateral drainage in MHBO. Both techniques are equivalent in terms of technical success, clinical success, rates of both early and late AEs, reintervention, and procedure-related mortality.