Background: s/Aims: Reported incidence of extrahepatic bile duct cancer is higher in Asians than in Western populations. Korea, in particular, is one of the countries with the highest incidence rates of extrahepatic bile duct cancer in the world. Although research and innovative therapeutic modalities for extrahepatic bile duct cancer are emerging, clinical guidelines are currently unavailable in Korea. The Korean Society of Hepato-Biliary-Pancreatic Surgery in collaboration with related societies (Korean Pancreatic and Biliary Surgery Society, Korean Society of Abdominal Radiology, Korean Society of Medical Oncology, Korean Society of Radiation Oncology, Korean Society of Pathologists, and Korean Society of Nuclear Medicine) decided to establish clinical guideline for extrahepatic bile duct cancer in June 2021. Methods: Contents of the guidelines were developed through subgroup meetings for each key question and a preliminary draft was finalized through a Clinical Guidelines Committee workshop. Results: In November 2021, the finalized draft was presented for public scrutiny during a formal hearing. Conclusions The extrahepatic guideline committee believed that this guideline could be helpful in the treatment of patients.

Background/Aims: Although important, clinically significant liver fibrosis is often overlooked in the general population. We aimed to examine the prevalence of clinically significant liver fibrosis using noninvasive tests (NITs) in the general population. Methods: We collected data from four databases (MEDLINE, Embase, Cochrane Library, and KoreaMed) from inception to June 13, 2023. Original articles reporting the prevalence of clinically significant liver fibrosis in the general population were included. The Stata metaprop function was used to obtain the pooled prevalence of liver fibrosis with NITs in the general population. Results: We screened 6,429 articles and included 45 eligible studies that reported the prevalence of clinically significant liver fibrosis in the general population. The prevalence of advanced liver fibrosis, using the high probability cutoff of the fibrosis-4 (FIB-4) index, was 2.3% (95% confidence interval [CI], 1.2–3.7%). The prevalence of significant liver fibrosis, advanced liver fibrosis, and liver cirrhosis, assessed using vibration-controlled transient elastography (VCTE) among the general population, was 7.3% (95% CI, 5.9–8.8%), 3.5% (95% CI, 2.7–4.5), and 1.2% (95% CI, 0.8–1.8%), respectively. Region-based subgroup analysis revealed that the highest prevalence of advanced fibrosis using the high probability cutoff of the FIB-4 index was observed in the American region. Furthermore, the American region exhibited the highest prevalence of significant liver fibrosis, advanced liver fibrosis, and liver cirrhosis, using VCTE. Conclusions Previously undiagnosed clinically significant liver fibrosis is found in the general population through NITs. Future research is necessary to stratify the risk in the general population.

Background: s/Aims: Liver stiffness measurement (LSM) using vibration-controlled transient elastography (VCTE) can assess fibrotic burden in chronic liver diseases. The systematic review and meta-analysis was conducted to determine whether LSM using VCTE can predict the risk of development of hepatocellular carcinoma (HCC) in chronic hepatitis B (CHB) patients. Methods: A systematic literature search of the Ovid-Medline, EMBASE, Cochrane, and KoreaMed databases (from January 2010 to June 2023) was conducted. Of the 1,345 individual studies identified, 10 studies that used VCTE were finally registered. Hazard ratios (HRs) and the 95% confidence intervals (CIs) were considered summary estimates of treatment effect sizes of ≥11 kilopascal (kPa) standard for HCC development. Meta-analysis was performed using the restricted Maximum Likelihood random effects model. Results: Among the ten studies, data for risk ratios for HCC development could be obtained from nine studies. When analyzed for the nine studies, the HR for HCC development was high at 3.33 (95% CI, 2.45–4.54) in CHB patients with a baseline LSM of ≥11 kPa compared to patients who did not. In ten studies included, LSM of ≥11 kPa showed the sensitivity and specificity for predicting HCC development were 61% (95% CI, 50–71%) and 78% (95% CI, 66–86%), respectively, and the diagnostic accuracy was 0.74 (95% CI, 0.70–0.77). Conclusions The risk of HCC development was elevated in CHB patients with VCTE-determined LSM of ≥11 kPa. This finding suggests that VCTE-determined LSM values may aid the risk prediction of HCC development in CHB patients.

Background/Aims: The Fibrosis-4 index (FIB-4) is a noninvasive test widely used to rule out advanced liver fibrosis (AF) in patients with nonalcoholic fatty liver disease (NAFLD). However, its diagnostic accuracy in NAFLD patients with type 2 diabetes mellitus (T2DM) is controversial due to the high prevalence of AF in this population. Methods: Research focusing on the diagnostic accuracy of FIB-4 for liver fibrosis as validated by liver histology in NAFLD patients with T2DM was included, and 12 studies (n=5,624) were finally included in the meta-analysis. Sensitivity, specificity, hierarchical summary receiver operating characteristic (HSROC), positive predictive values (PPVs), and negative predictive values (NPVs) at low cutoffs (1.3–1.67) and high cutoffs (2.67–3.25) for ruling in and out AF were calculated. Results: At low cutoffs, the meta-analysis revealed a sensitivity of 0.74, specificity of 0.62, and HSROC of 0.75. At high cutoffs, the analysis showed a sensitivity of 0.33, specificity of 0.92, and HSROC of 0.85, suggesting FIB-4 as useful for identifying or excluding AF. In subgroup analyses, high mean age and F3 prevalence were associated with lower sensitivity. The calculated NPV and PPV were 0.82 and 0.49 at low cutoffs, whereas the NPV was 0.28 and the PPV was 0.70 at high cutoffs. There were insufficient estimated NPVs <0.90 at a hypothesized prevalence of AF >30% at an FIB-4 cutoff range of 1.3–1.67. Conclusions Collectively, FIB-4 has moderate diagnostic accuracy for identifying or excluding AF in NAFLD patients with T2DM, but more evidence must be accumulated due to the limited number of currently reported studies and their heterogeneity.

Background: s/Aims: Despite advances in antiviral therapy for hepatitis C virus (HCV) infection, hepatocellular carcinoma (HCC) still develops even after sustained viral response (SVR) in patients with advanced liver fibrosis or cirrhosis. This meta-analysis investigated the predictive performance of vibration-controlled transient elastography (VCTE) and fibrosis 4-index (FIB-4) for the development of HCC after SVR. Methods: We searched PubMed, MEDLINE, EMBASE, and the Cochrane Library for studies examining the predictive performance of these tests in adult patients with HCV. Two authors independently screened the studies’ methodological quality and extracted data. Pooled estimates of sensitivity, specificity, and area under the curve (AUC) were calculated for HCC development using random-effects bivariate logit normal and linear-mixed effect models. Results: We included 27 studies (169,911 patients). Meta-analysis of HCC after SVR was possible in nine VCTE and 15 FIB-4 studies. Regarding the prediction of HCC development after SVR, the pooled AUCs of pre-treatment VCTE >9.2–13 kPa and FIB-4 >3.25 were 0.79 and 0.73, respectively. VCTE >8.4–11 kPa and FIB-4 >3.25 measured after SVR maintained good predictive performance, albeit slightly reduced (pooled AUCs: 0.77 and 0.70, respectively). The identified optimal cut-off value for HCC development after SVR was 12.6 kPa for pre-treatment VCTE. That of VCTE measured after the SVR was 11.2 kPa. Conclusions VCTE and FIB-4 showed acceptable predictive performance for HCC development in patients with HCV who achieved SVR, underscoring their utility in clinical practice for guiding surveillance strategies. Future studies are needed to validate these findings prospectively and validate their clinical impact.

Background: s/Aims: This meta-analysis examined whether preoperative vibration-controlled transient elastography (VCTE) can predict postoperative complications and recurrence in patients undergoing hepatic resection for hepatocellular carcinoma (HCC). Methods: A systematic literature search was conducted using Ovid-Medline, EMBASE, Cochrane, and KoreaMed databases. Out of 431 individual studies, thirteen published between 2008 and 2022 were included. Five studies focused on HCC recurrence, while eight examined postoperative complications. Results: The meta-analysis of five studies on HCC recurrence showed that the high-risk group with a high VCTE score had a significantly increased recurrence rate after hepatic resection (hazard ratio 2.14). The cutoff value of VCTE in the high-risk group of HCC recurrence was 7.4–13.4 kPa, the sensitivity was 0.60 (95% confidence interval [CI] 0.47–0.72), and the specificity was 0.60 (95% CI 0.46–0.72). The area under the receiver operating characteristic curve (AUC) of the liver stiffness measured by VCTE to predict the HCC recurrence was 0.63 (95% CI 0.59–0.67). The meta-analysis on the postoperative complications revealed a significantly increased risk of postoperative complications in the high-risk group (12–25.6 kPa) with a high VCTE value (odds ratio [OR], 8.32). The AUC of the liver stiffness measured by VCTE to predict the postoperative complications was 0.87 (95% CI 0.84–0.90), the sensitivity was 0.76 (95% CI 0.55–0.89) and the specificity was 0.85 (95% CI 0.73–0.92). Conclusions This meta-analysis suggests that preoperative VCTE in patients undergoing hepatic resection for HCC is useful in identifying individuals at a high risk of postoperative complications and HCC recurrence.

Background/Aims: The assessment of liver fibrosis is crucial for managing autoimmune liver diseases such as primary biliary cholangitis (PBC), autoimmune hepatitis (AIH), and primary sclerosing cholangitis (PSC). However, data on the efficacy of noninvasive tests for these diseases are limited. This meta-analysis evaluated the diagnostic accuracy of vibration-controlled transient elastography (VCTE) for staging fibrosis in patients with autoimmune liver disease. Methods: Searches were conducted in PubMed, Embase, CINAHL, Web of Science, and Cochrane Library databases to assess the diagnostic accuracy of VCTE against histology as the reference standard in adult patients with autoimmune liver disease. The summary area under the curve (sAUC) and diagnostic odds ratio were calculated for significant fibrosis (SF), advanced fibrosis (AF), and cirrhosis, according to liver biopsy. Results: Fourteen articles were included, comprising 559 PBC patients from six studies, 388 AIH patients from five studies, and 151 PSC patients from three studies. VCTE demonstrated good performance for fibrosis staging in PBC, AIH, and PSC. In PBC, sAUCs of VCTE were 0.87, 0.89, and 0.99 for staging SF, AF, and cirrhosis, respectively. In AIH, the sAUCs were 0.88, 0.88, and 0.92, respectively, while in PSC, they were 0.88, 0.95, and 0.92, respectively. The cutoff values for AF were 7.5–17.9 kPa in PBC, 8.18–12.1 kPa in AIH, and 9.6 kPa in PSC. Conclusions VCTE shows high diagnostic accuracy for staging liver fibrosis in patients with autoimmune liver diseases. This non-invasive method serves as a valuable tool for the evaluation and monitoring of fibrosis in these lifelong diseases.

Background: s/Aims: Accurate diagnosis of significant liver fibrosis in patients with chronic hepatitis B (CHB) is crucial when determining whether to initiate antiviral treatment (AVT). We conduct a meta-analysis to assess the diagnostic performance of vibration-controlled transient elastography (VCTE) for significant liver fibrosis in AVT-naïve CHB patients with serum alanine transaminase (ALT) levels within 5-fold the upper limit of normal (ULN). Methods: The Ovid-Medline, EMBASE, Cochrane, and KoreaMed databases were searched to identify studies that compared the performance of VCTE and liver biopsy (reference standard) when diagnosing significant liver fibrosis (≥F2) in AVT-naïve CHB patients with ALT within 5-fold the ULN. A hierarchical summary receiver operating characteristic curve (HSROC) and bivariate model were performed to evaluate the diagnostic performance of VCTE in the meta-analysis. Results: Eight studies (2,003 patients) were included. The summary sensitivity and specificity for diagnosis of significant liver fibrosis were 0.78 (95% confidence interval [CI], 0.66–0.86) and 0.72 (95% CI, 0.60–0.82), respectively. The HSROC for the diagnosis of significant liver fibrosis was 0.81 (95% CI, 0.72–0.86). The optimal cutoff value of VCTE for diagnosis of significant liver fibrosis was 7.7 kPa with a sensitivity of 0.64 (95% CI, 0.50–0.76) and specificity of 0.83 (95% CI, 0.72–0.90). Conclusions Our study demonstrated that VCTE has an acceptable diagnostic performance for significant liver fibrosis in AVT-naïve CHB patients with ALT within 5-fold the ULN.

Background/aims: Opinions differ regarding vibration-controlled transient elastography and magnetic resonance elastography (VCTE/MRE) cut-offs for diagnosing advanced fibrosis (AF) in patients with non-alcoholic fatty liver disease (NAFLD). We investigated the diagnostic performance and optimal cut-off values of VCTE and MRE for diagnosing AF. Methods: Literature databases, including Medline, EMBASE, Cochrane Library, and KoreaMed, were used to identify relevant studies published up to June 13, 2023. We selected studies evaluating VCTE and MRE regarding the degree of liver fibrosis using liver biopsy as the reference. The sensitivity, specificity, and area under receiver operating characteristics curves (AUCs) of the pooled data for VCTE and MRE for each fibrosis stage and optimal cut-offs for AF were investigated. Results: A total of 19,199 patients from 63 studies using VCTE showed diagnostic AUC of 0.83 (95% confidence interval: 0.80–0.86), 0.83 (0.80–0.86), 0.87 (0.84–0.90), and 0.94 (0.91–0.96) for ≥F1, ≥F2, ≥F3, and F4 stages, respectively. Similarly, 1,484 patients from 14 studies using MRE showed diagnostic AUC of 0.89 (0.86–0.92), 0.92 (0.89–0.94), 0.89 (0.86–0.92), and 0.94 (0.91–0.96) for ≥F1, ≥F2, ≥F3, and F4 stages, respectively. The diagnostic AUC for AF using VCTE was highest at 0.90 with a cut-off of 7.1–7.9 kPa, and that of MRE was highest at 0.94 with a cut-off of 3.62–3.8 kPa. Conclusions VCTE (7.1–7.9 kPa) and MRE (3.62–3.8 kPa) with the suggested cut-offs showed favorable accuracy for diagnosing AF in patients with NAFLD. This result will serve as a basis for clinical guidelines for non-invasive tests and differential diagnosis of AF.