Impact of Peri-Procedural Antibiotics on Post-ERCP Infectious Adverse Events With Distal Malignant Biliary Obstruction.

[BACKGROUND AND AIMS] Malignant biliary obstruction (MBO) often necessitates endoscopic retrograde cholangiopancreatography (ERCP) for biliary drainage. Although ERCP is the standard treatment, post-procedural infections such as cholangitis and cholecystitis remain clinically important. Current guidelines recommend prophylactic antibiotics only for high-risk cases. However, data focused specifically on patients with distal MBO (DMBO) undergoing stent placement are limited. This study evaluated the effect of peri-ERCP antibiotics on post-ERCP infectious adverse events in DMBO.

[METHODS] This multicenter retrospective study included 508 patients who underwent initial biliary stent placement for DMBO between January 2020 and August 2024 at five institutions. Patients were categorized according to whether they received peri-ERCP antibiotics. Propensity score matching (1:1) was performed using clinically relevant covariates. The primary outcome was the incidence of infectious adverse events (cholangitis or cholecystitis) within 5 days of ERCP.

[RESULTS] After matching, 165 patients were included in each group. The incidence of infectious adverse events was significantly lower in the peri-ERCP antibiotic group (3.6%) compared with the nonantibiotic group (10.3%), with a risk difference (RD) of 6.7% (95% confidence interval [CI]: 1.2-12.1). Post-ERCP pancreatitis occurred in 10 patients (6.1%) without prophylaxis and 16 (9.7%) with prophylaxis, showing no significant difference (RD: -3.6%, 95% CI: -9.4 to 2.2). Subgroup analysis suggested greater benefit in patients with nonpancreatic cancer (RD, 0.206; 95% CI, 0.07-0.342; p = 0.011) or a bile duct diameter > 10 mm (RD, 0.104; 95% CI, 0.046-0.163; p = 0.001).

[CONCLUSIONS] Peri-ERCP antibiotics may reduce post-ERCP infectious adverse events in patients with DMBO.