# Endoscopic Ultrasound-Guided Versus Percutaneous Transhepatic Biliary Drainage After Failed Endoscopic Retrograde Cholangiopancreatography in Malignant Biliary Obstruction: A Single-Center Retrospective Cohort

## TL;DR

This study compares two drainage methods for biliary blockage after failed ERCP, finding that endoscopic ultrasound-guided drainage offers better survival but more complications.

## Contribution

The study provides a direct comparison of EUS-BD and PTBD outcomes in malignant biliary obstruction after ERCP failure, focusing on survival and complications.

## Key findings

- EUS-BD showed significantly better six-month survival compared to PTBD.
- EUS-BD had higher complication rates compared to PTBD.
- Both methods achieved 100% technical success in relieving biliary obstruction.

## Abstract

Malignant biliary obstruction (MBO) can be managed through endoscopic retrograde cholangiopancreatography (ERCP) with stent placement. However, in less than 10% of cases, this method fails to restore biliary flow. In such cases, endoscopic ultrasound biliary drainage methods (EUS-BD) and percutaneous transhepatic biliary drainage (PTBD) can be used as an alternative approach. It remains unclear which procedure offers better outcomes for patients. In this study of 101 patients with MBO after a failed ERCP, we compared these two methods in terms of effectiveness, safety, and survival. Both techniques successfully relieved bile duct obstruction, but they differed in complication rates and patient survival. Our findings may help clinicians select the most appropriate drainage method and inform future research aimed at improving care for patients with advanced biliary cancers.

Background: After a failed endoscopic retrograde cholangiopancreatography (ERCP) for malignant biliary obstruction (MBO), second-line drainage is performed with endoscopic ultrasound-guided biliary drainage (EUS-BD) or percutaneous transhepatic biliary drainage (PTBD). We compared their effectiveness, safety, and short-term survival. Methods: We conducted a single-center retrospective cohort of 101 adults with MBO after they had experienced a failed ERCP (EUS-BD n = 37; PTBD n = 64). Allocation was non-randomized and driven by operational availability. Baseline laboratory tests (complete blood count, platelets, and C-reactive protein) and derived indices (neutrophil-to-lymphocyte ratio [NLR], platelet-to-lymphocyte ratio [PLR], lymphocyte-to-monocyte ratio [LMR], systemic immune-inflammation index [SII], systemic inflammation response index [SIRI], neutrophil-to-platelet score [NPS], and lymphocyte-to-CRP ratio [LCR]) were compared. Outcomes that were a technical success include: an early biochemical response (bilirubin reduction), complications (Clavien–Dindo), length of stay (LOS), and overall survival (OS). Between-group comparisons used the two-sided Mann–Whitney U test (continuous) and Fisher’s exact (binary) test. Survival was assessed by the Kaplan–Meier estimator using log-rank testing. To address later adoption of EUS-BD, we also estimated a restricted mean survival time of 180 days (RMST_0–180) with 95% confidence intervals (CIs). Results: Baseline inflammatory markers and composite indices were similar; baseline total bilirubin was higher in PTBD. The technical success was 100% in both groups. Early biochemical response was 86.5% after EUS-BD vs. 78.1% after PTBD (p = 0.43). Any complication occurred in 29.7% vs. 12.5% (p = 0.04); major complications (Clavien–Dindo ≥ III) occurred in 10.8% vs. 0% (p = 0.02), respectively; and the LOS did not differ (p = 0.21). OS favored EUS-BD (median 143 vs. 54 days and log-rank p = 0.012). RMST_0–180 was 111.1 days for EUS-BD vs. 71.4 days for PTBD (difference + 39.6 days; 95% CI 11.3–65.9). Conclusions: After a failed ERCP for MBO, EUS-BD and PTBD achieved universal technical success and similar early biochemical responses, but EUS-BD was associated with higher complication rates and a significantly longer six-month survival. These findings support the individualized selection balancing procedural risk with the anticipated survival benefit and highlight the need for prospective comparative studies.