Patients undergoing pancreaticoduodenectomy after preoperative biliary drainage are at increased risk of surgical site infections (SSI) due to bile colonization. Recent guidelines recommend the use of piperacillin/tazobactam instead of cephalosporins for antibiotic prophylaxis in this population. However, the relevance of this strategy may depend on local microbiological ecology.

This monocentric ambispective cohort study aims to compare SSI rates between two periods: before and after implementation of piperacillin/tazobactam prophylaxis. The study also evaluates microbiological profiles of bile cultures, antibiotic susceptibility, and postoperative antibiotic exposure.

The primary hypothesis is that adaptation of antibiotic prophylaxis to local ecology may optimize outcomes while limiting unnecessary exposure to broad-spectrum antibiotics.

Inclusion Criteria:

• Adult patients (> 18 yrs)
• Scheduled for pancreatic surgery
• Presence of preoperative biliary stent
• Postoperative admission to surgical ICU or intermediate care unit

Exclusion Criteria:

• decline to participate

Adult patients undergoing pancreaticoduodenectomy for malignancy with preoperative biliary drainage at Nancy University Hospital between January 2022 and December 2025.