Types of Self-Expandable Metal Stents for Palliative Drainage of Unresectable Extrahepatic Malignant Biliary Obstruction: A Network Meta-Analysis of Randomized Controlled Trials
Background: The optimal self-expandable metallic stent (SEMS) choice for endoscopic drainage of unresectable extrahepatic malignant biliary obstruction (MBO) with endoscopic retrograde cholangiopancreatography (ERCP) remains unclear due to limited randomized controlled trial (RCT) evidence. Prior meta-analyses have relied on observational data, introducing heterogeneity and bias. To overcome these limitations, an RCT-only network meta-analysis (NMA) was performed to evaluate the efficacy and safety of SEMS types. Methods: A literature search was conducted to identify RCTs assessing fully covered SEMS (FCSEMS), partially covered SEMS (PCSEMS), and/or uncovered SEMS (UCSEMS) for ERCP drainage of unresectable extrahepatic MBO. Study outcomes included recurrent biliary obstruction (RBO), specific causes of RBO, overall survival (OS), and adverse events (AEs). A frequentist NMA was performed to estimate hazard ratios (HRs) and incidence rate ratios (IRRs) with their 95% confidence intervals and overall P-scores. Results: Ten RCTs (1,659 patients) were included. There were no significant differences in time to RBO, incidence of any RBO, or OS between stent types. UCSEMS had the lowest rates of stent migration, tumor overgrowth, and sludge occlusion, whereas FCSEMS most effectively prevented tumor ingrowth. AE rates were similar across groups; however, only FCSEMS, but not PCSEMS, had significantly higher rates of acute cholecystitis than UCSEMS in patients with an intact gallbladder. Conclusion: There were no differences in RBO, OS, or AE excluding acute cholecystitis between each SEMS type, although each type has its advantages and disadvantages. FCSEMS was associated with a higher risk of acute cholecystitis, emphasizing careful patient selection, particularly regarding gallbladder status.
Diagnostic Accuracy Performance of Fluorescence In Situ Hybridization (FISH) for Biliary Strictures: A Systematic Review and Meta-Analysis
Background and Aims: This systematic review and meta-analysis aims to compare the performance of UroVysion® FISH based on the different definitions of a positive result used in published literature with the goal of determining the optimal FISH definition for detecting pancreaticobiliary malignancy. Methods: A systematic literature search identified studies from database inception to Sept 2024 that evaluated the diagnostic performance of FISH in determining malignancy among patients with biliary strictures. All thresholds for positive FISH, as defined by the individual study, were included in this review. Subgroup analysis was performed based on the definitions of positive FISH as follows: (1) polysomy only; (2) polysomy, tetrasomy, or trisomy; and (3) polysomy or 9p deletion. Results: Eighteen studies comprising 2516 FISH specimens were analyzed, including 1133 (45.0%) with malignancy. Using a threshold for positivity as defined in individual studies, the overall sensitivity of FISH was 57.6% (95% confidence interval [CI], 49.4–65.4%), and the overall specificity was 87.8% (95% CI, 79.2–93.2%). Subgroup analysis showed that polysomy as the threshold for positive FISH yielded a sensitivity of 49.4% (95% CI, 43.2–55.5%), with an increased specificity of 96.2% (95% CI, 92.7–98.1%), while polysomy + tetrasomy/trisomy as positive FISH resulted in an increased sensitivity of 64.3% (95% CI 55.4–72.2%) but a decreased specificity of 78.9% (95% CI 64.4–88.5%). The addition of 9p deletion to polysomy as the criteria for a positive test resulted in a non-significant increase in sensitivity (54.7% (95% CI 42.4–66.5%) while maintaining specificity (95.1% (95% CI 84.0–98.6%). Conclusions: Based on these findings, polysomy only or polysomy/9p deletion should be considered as the criterion for defining a positive FISH test to improve diagnostic sensitivity while maintaining high specificity.
Meta-analysis of diagnostic performance of fluorescence in situ hybridization (FISH) for biliary strictures