EUS-guided gallbladder drainage (EUS-GBD) with lumen-apposing metal stent (LAMS) reported high technical/clinical success but not negligible adverse events (AEs) and stent dysfunction (SD). Based on evidence from pancreatic fluid collection drainage and EUS-choledochoduodenostomy, the placement of a coaxial double-pigtail plastic stent (DPPS) within the LAMS may reduce these events. This study aimed to assess whether inserting a DPPS coaxially through the LAMS during EUS-GBD decreases the risk of AEs and stent dysfunction.

This is an interim analysis of an ongoing multicentre study conducted across eight centres, including consecutive adult patients (2018–2025) who underwent successful EUS-GBD with LAMS for acute cholecystitis or distal malignant biliary obstruction. Patients with perforated gallbladder or with contained perforation, coagulopathy, non-patent cystic duct (in case of DMBO) were excluded. As the target sample size has not yet been reached, analyses represent a direct comparison without propensity-score matching. Stent dysfunction was defined as a composite endpoint including recurrent jaundice, obstruction, migration, buried stent, cholangitis or new onset/recurrent AC during follow-up The primary endpoint was the effectiveness of coaxial DPPS placement in reducing overall AEs and SD. Secondary endpoints included identifying risk factors associated with AEs and SD.

A total of 273 patients were included (141 M; mean age 80 ± 12 years); 216 underwent EUS-GBD for acute cholecystitis. Coaxial DPPS placement was performed in 41 patients, predominantly via a trans-gastric approach. Overall, AEs occurred in 9/41 (22%) patients in LAMS+DPPS group and 42/230 (18.3%) in LAMS alone group. Kaplan–Meier analyses revealed no significant differences between the LAMS+DPPS and LAMS-alone groups in AE-free survival (log-rank test, p = 0.49) or SD-free survival (log-rank test, p = 0.10) (Fig.1;Fig.2). Binary logistic regression identified previous percutaneous transhepatic biliary drainage (PTBD) (OR 3.197; 95%CI 1.00–2.32; p = 0.048) and the presence of perihepatic ascites (OR 0.210; 95%CI 0.00–1.00; p=0.050) as predictors of AEs. The transgastric route showed a trend toward increased AEs (OR 0.515; 95%CI 0.03–1.36; p=0.061).

In this interim analysis, coaxial DPPS within LAMS did not reduce AEs or SD. Notably, prior PTBD, ascites and a transgastric approach were identified as potential risk factors for AEs. A larger cohort with propensity-score matching or a RCT is necessary to verify this hypothesis.