Bile Bacterial Colonization, POPF Risk, and Survival After Pancreatoduodenectomy

A retrospective cohort study examined whether intraoperative bile microbiology relates to morbidity and survival among 138 patients undergoing pancreatoduodenectomy for histologically confirmed pancreatic ductal adenocarcinoma, with bile sampled at common bile duct transection and sent for culture.

The authors report positive bile cultures in 76.8% of patients, with bacteria with resistance mechanisms identified in 12.3% of samples. Analyses focused on postoperative pancreatic fistula severity—particularly clinically relevant POPF (ISGPS grade B/C)—and overall survival.

For morbidity, the authors assessed bacteriobilia in multivariable logistic regression models for clinically relevant POPF and for grade-specific fistula outcomes. The adjustment set included age, sex, BMI, ASA physical status, and pancreatic duct anastomosis technique (duct-to-mucosa vs invagination). In these adjusted analyses, bacteriobilia was reported as independently associated with clinically relevant POPF (grade B/C) (OR 5.50; p = 0.034) and with POPF grade B (OR 8.04; p = 0.048).

Microbiology findings describe polyetiological bile colonization, with 223 bacterial isolates spanning 53 species and a mean of three microbial species per sample. The most frequent isolates were reported as Enterococcus faecalis (18.39%), Escherichia coli (14.35%), and Klebsiella pneumoniae (12.11%). Resistant organisms were discussed as a distinct subgroup of bacteria with resistance mechanisms (BRM), defined as isolates exhibiting specific, well-characterized antimicrobial resistance mechanisms, with descriptions of resistance types among identified isolates. In multivariable modeling paralleling the bacteriobilia analysis, the authors report this resistant-organism subgroup as independently associated with POPF grade C (OR 6.17; p = 0.047).

For survival, Kaplan–Meier analysis showed a shorter median overall survival in the bile-positive group versus the bile-negative group (26.7 vs 54.7 months; log-rank p = 0.009), and the authors report that positive culture status remained associated with reduced overall survival in adjusted Cox regression (HR 1.95; p = 0.019). The Cox modeling is described as incorporating cancer stage via nodal status (N stage) and included an interaction term (culture × N stage) that was not statistically significant in the reported results.

Key Takeaways:

• Bacteriobilia was reported as common in this pancreatoduodenectomy PDAC cohort, with a subset of samples containing bacteria with resistance mechanisms.
• In adjusted logistic regression, bacteriobilia was reported as associated with higher odds of clinically relevant POPF, while resistant organisms were reported as associated with POPF grade C.
• Positive bile culture status was reported as associated with shorter overall survival in both unadjusted (Kaplan–Meier) and adjusted (Cox regression including cancer stage) analyses.