Endoscopic Ultrasound-Guided Biliary Drainage in Altered Gastrointestinal Anatomy: A Systematic Review and Meta-Analysis

Summary

This study presents a meta-analysis comparing endoscopic ultrasound-guided biliary drainage (EUS-BD) and endoscopic retrograde cholangiopancreatography (ERCP) for biliary obstruction in patients with altered gastrointestinal anatomy.

Abstract

ERCP intubation is often difficult in patients with biliary obstruction and changes in gastrointestinal structure, such as after Roux-en-Y or Billroth II surgery. EUS-BD is an alternative method. This meta-analysis should systematically compare the efficacy and safety of EUS-BD and ERCP in these patients. Studies were retrieved from PubMed, Embase, Web of Science, and the Cochrane Library from 2011 to 2026. Original studies comparing EUS-BD and ERCP in patients with biliary obstruction and a history of gastrointestinal reconstruction surgery were included. Two researchers independently carried out literature screening, data extraction, and quality evaluation. A meta-analysis was conducted using Review Manager. The main outcome measures are technical success rate, clinical success rate, adverse events, and procedure time. A total of 6 studies involving 572 patients (201 in the EUS-BD group and 371 in the ERCP group) were included in the technical success analysis. The meta-analysis demonstrated that the pooled technical success rate was 90.5% (182/201) for the EUS-BD group and 70.4% (261/371) for the ERCP group, yielding an odds ratio (OR) of 3.60 (95% CI: 2.12–6.13; p < 0.00001). For clinical success, the pooled odds ratio was 3.52 (95% CI: 2.07–5.98; p < 0.00001), demonstrating a statistically significant advantage over ERCP. In terms of safety, there was no difference in the overall incidence of adverse events between the two groups (25.9% vs. 20.5%; OR: 1.54, 95% CI: 0.97–2.44). In patients with biliary obstruction and surgically altered gastrointestinal anatomy, EUS-BD was associated with higher pooled technical and clinical success rates in available observational studies, along with shorter procedure time than ERCP. However, current evidence remains insufficient to establish a definitive difference in overall adverse events. EUS-BD represents a viable and highly effective alternative drainage modality for this challenging population, particularly when standard ERCP is anticipated to be technically demanding.

Introduction

Biliary obstruction is an obstructive condition. Pathologically, the biliary system is blocked¹. The etiologies include pancreatic diseases, cholangiocarcinoma, ampullary cancer, gallstones, surgical conditions, etc². The core pathological change is bile stasis and high pressure in the bile duct, which leads to a series of symptoms and complications³. Endoscopic interventional techniques such as ERCP-BD and EUS-BD are clinically used⁴. ERCP-BD is the main palliative treatment method for biliary obstruction, which can relieve symptoms and prolong the survival period⁵. Anatomical problems may affect its success, especially when the ampulla is invaded by the duodenum, which is the main cause of ERCP-BD failure, with a failure rate ranging from 0.5% to 16%. Procedure - related pancreatitis is a major problem in clinical practice^6,7. Despite these limitations, ERCP-BD continues to be a cornerstone intervention, and numerous meta-analyses have been conducted to systematically compare its therapeutic efficacy against alternative drainage methods, such as EUS-BD^8,9.

In recent years, endoscopic ultrasound-guided biliary drainage has rapidly emerged in the treatment of malignant biliary obstruction, with its clinical applications significantly expanding^4,10. EUS is a cutting-edge medical device that combines endoscopic and ultrasonic technologies, offering outstanding advantages: Firstly, it provides a more flexible puncture pathway, allowing direct access to the intrahepatic or extrahepatic bile ducts via the stomach or proximal duodenum, thereby offering a reliable drainage route for patients with duodenal invasion or postsurgical anatomical alterations. Secondly, this technology avoids complications related to ERCP, especially without the need for pancreatic duct intubation to reduce the risk of the pancreas¹¹. In addition, under real-time ultrasonic guidance, EUS-BD can evaluate the tissue around the bile duct and the infiltration of tumors, thereby providing information for supplementary diagnosis and staging. Furthermore, this technique itself serves as a key solution to overcome the clinical impasses of failed ERCP or postoperative reobstruction, providing a strategy for treatment pathways¹².

While numerous meta-analyses have systematically compared EUS-BD and ERCP for conventional biliary drainage^12,13,14, evidence remains scarce regarding patients with surgically altered gastrointestinal anatomy (SAGA). In this specific population, standard ERCP is technically demanding and often unsuccessful due to extensive anatomical distortion. It is hypothesized that EUS-BD, which inherently bypasses these anatomical barriers via direct transmural access, will demonstrate superior technical and clinical success rates alongside a comparable safety profile when compared to ERCP. To the best of current knowledge, this is the first systematic review and meta-analysis specifically designed to evaluate the comparative efficacy and safety of these two modalities in the SAGA population. By providing a robust synthesis of current evidence, this study aims to offer novel insights and establish evidence-based guidance for clinical decision-making in this challenging demographic.

Protocol

Guidelines and official logging

The reporting complied with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement; the completed PRISMA checklist is provided in the Supplementary Materials. The study protocol was prospectively registered in PROSPERO (CRD420261297962). All the tools or materials used for this study are listed in the Table of Materials.

Search strategy

Three reviewers independently performed the comprehensive electronic search in duplicate, covering records from January 1st, 2011, to January 1st, 2026. This study employed a coverage strategy in its search, systematically retrieving electronic databases including PubMed, Embase, Web of Science, and the Cochrane Central Register of Controlled Trials (CENTRAL). Eligible studies are confined to observational cohort studies. To capture the most recent evidence, a supplementary search was conducted using the same databases and search strategy to identify any newly published observational cohort studies that met the inclusion criteria.

Inclusion criteria

The systematic review employed search terms such as: “biliary obstruction,” “obstructive jaundice,” “ERCP,” “EUS,” and “endoscopic ultrasound.” “surgical altered anatomy”, “common bile duct stones,” and “digestive tract reconstruction”. The detailed Boolean search strings and syntax specific to each database are provided in Supplementary Tables 1–4. There were no language restrictions, but the search was restricted to the last 15 years, from January 1st, 2011, to January 1st, 2026. For patients, the inclusion criteria were as follows: eligible patients were over 20 years of age¹⁵; EUS-BD (inclusive of any transmural or transpapillary ultrasound-guided approaches) or ERCP (including standard and balloon enteroscopy-assisted ERCP) was performed to manage their biliary obstruction; and they had a history of upper gastrointestinal surgery with Roux-en-Y or Billroth II reconstruction¹⁶. Technical or narrative reviews, noncomparative studies, case reports, and studies reporting on other organ obstructions were excluded. The references of the articles identified after the initial search were also manually reviewed.

Data extraction

Two reviewers (Yu, Liu) independently extracted detailed trial characteristics into Table 1, rigorously recording: specific EUS-BD and ERCP techniques, underlying surgical anatomy, benign versus malignant indications, study-specific definitions of technical and clinical success (including bilirubin reduction thresholds and assessment time points), and operator or institutional expertise. The data analyzed includes technical success, clinical success, cholangitis, pancreatitis, adverse events, stent occlusion, survival time, procedure time, length of hospital stay, stent dysfunction, and stent migration. For observational cohort studies with more than two groups or employing factorial designs that allowed multiple comparisons, only the relevant information and data pertaining to the research question as reported in the original publications were selectively extracted. If a meta-analysis indicated the inclusion of unpublished data obtained directly from the original authors, this data was extracted from its forest plots, and the original trial reports were cross-referenced to verify eligibility against the inclusion criteria. Data confirmed as relevant to our outcomes of interest were then integrated with data extracted from the primary trial publications for analysis.

Definitions

In this meta-analysis, EUS-BD was evaluated as a comprehensive interventional category. The specific procedural approaches subsumed under EUS-BD included EUS-guided hepaticogastrostomy (EUS-HGS), EUS-guided choledochoduodenostomy (EUS-CDS), EUS-guided antegrade intervention (EUS-AG), and the EUS-guided rendezvous technique (EUS-RV). For the purpose of the primary statistical analysis, outcome data from all these specific EUS-BD modalities were comprehensively pooled into a single experimental cohort to be compared against the ERCP control group. Technical success was determined based on the following criterion: the planned placement of a metal stent or removal of stones was successfully completed via EUS or ERCP. While clinical success was predominantly defined as a decrease in serum total bilirubin to below half of the baseline level within 1 to 4 weeks^15,17,18,19, the specific definitions utilized by each original study were adopted. These minor study-specific variations in defining clinical success (e.g., differences in the evaluation timeframe or the inclusion of clinical symptom resolution) were meticulously documented during data extraction.

All adverse events occurring within 14 days postoperatively were defined as overall adverse events, which included procedure-related events (bleeding, perforation including biliary or duodenal, acute pancreatitis, bile leakage); infectious events (cholangitis, cholecystitis, liver abscess, bacteremia/sepsis); stent-related events (early stent occlusion, migration [intraperitoneal or intraluminal], malposition, late reobstruction due to tumor growth); systemic events (sedation-related cardiopulmonary complications, contrast agent allergy); and other rare events (subcapsular liver hematoma, pneumoperitoneum, portal vein injury, retained sheared guidewire, procedure-related death)^17,19. RBO was defined as a condition characterized by both symptomatic presentation and radiologically confirmed dilation of the biliary tract¹⁵. The procedure time was defined from endoscope insertion to stent placement^17,19.

Quality assessment

Two independent reviewers (Yu and Liu) methodically appraised the methodological quality of the included observational studies utilizing the Newcastle-Ottawa Scale (NOS). This validated tool evaluates studies across three domains: selection of the study groups, comparability of the groups, and ascertainment of the outcome of interest. Studies scoring 7 to 9 points were deemed to be of high methodological quality (low risk of bias), 4 to 6 points as moderate quality, and 0 to 3 points as low quality. Any discrepancies between the reviewers were resolved through consensus or consultation with a third reviewer (Zhang).

Statistical analysis

All statistical analyses were performed using Review Manager (RevMan) software, version 5.4 (The Cochrane Collaboration, London, UK). Dichotomous data were analyzed using odds ratios (OR) and 95% confidence intervals (CIs). A fixed-effects model was primarily utilized for data synthesis. Although a random-effects model is typically recommended when substantial heterogeneity (I² > 50%) is present, the limited number of included studies in our analysis (n = 6) could lead to an imprecise estimation of between-study variance (τ²). Therefore, the fixed-effects approach was primarily maintained to prevent disproportionate weight from being assigned to smaller trials, but importantly, a random-effects model was conducted as a pre-specified sensitivity analysis to evaluate the stability of the pooled estimates amidst clinical heterogeneity. The assessment of publication bias via funnel plot inspection and formal statistical testing was initially considered. However, in accordance with the Cochrane Handbook recommendations, this analysis was not performed because the number of included studies (n = 6) was insufficient (fewer than 10) to yield adequately powered and reliable results.

Study-specific effect estimates were first calculated. For dichotomous outcomes, this was expressed as an odds ratio (OR) with 95% CI, computed via the Mantel-Haenszel method. For continuous outcomes, the mean difference (MD) with 95% CI was derived using the inverse-variance method. Subsequently, pooled outcome proportions for each intervention group were estimated by the inverse-variance and logit transformation method. Heterogeneity was evaluated using the Cochran Q test and I² statistic. To explore potential sources of substantial heterogeneity, subgroup analyses were planned based on different EUS-BD approaches or types of gastrointestinal reconstruction. Additionally, sensitivity analyses were performed by sequentially omitting individual studies to assess the stability and reliability of the pooled results.

Results

Study selection and trial characteristics

A total of 528 records were initially identified through the systematic search^{16,17,18,19,20,21}. Following the removal of 37 duplicates, 491 records underwent title and abstract screening, resulting in the exclusion of 234 studies. A full-t...

Discussion

In this systematic review and meta-analysis of 6 observational cohort studies involving over 578 patients, success rates, safety profiles, and time-related outcomes between EUS-BD and ERCP-BD were compared for biliary tract obstruction in patients with altered gastrointestinal anatomy. The pooled analyses yielded the following key findings: 1) EUS-BD demonstrated significantly higher technical and clinical success rates, alongside a shorter procedure time, when compared to ERCP; 2) Although EUS-BD showed a numerically hi...

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Cochrane Library	Wiley	URL: https://www.cochranelibrary.com; Database accessed up to Jan 1, 2026	Literature search
Embase	Elsevier	URL: https://www.embase.com; Database accessed up to Jan 1, 2026	Literature search
EndNote	Clarivate	URL: https://endnote.com; Version 21	Reference and bibliography management
PROSPERO	Centre for Reviews and Dissemination, University of York	URL: https://www.crd.york.ac.uk/prospero; Identifier: CRD420261297962	Protocol registration
PubMed	U.S. National Library of Medicine	URL: https://pubmed.ncbi.nlm.nih.gov; Database accessed up to Jan 1, 2026	Literature search
Review Manager (RevMan)	The Cochrane Collaboration	URL: https://revman.cochrane.org; Version 5.4	Meta-analysis and forest plot
Web of Science	Clarivate	URL: https://www.webofscience.com; Database accessed up to Jan 1, 2026	Literature search