Impact of fungal biliary colonization on postoperative outcomes following pancreaticoduodenectomy: A systematic review

Background and Objective: Pancreaticoduodenectomy (PD) is associated with substantial postoperative morbidity, with infectious complications representing a major contributor. Preoperative biliary drainage (PBD) often leads to bile contamination, but the clinical significance of fungal colonization, particularly by Candida species, remains unclear. This systematic review aimed to evaluate the impact of fungal biliary colonization on postoperative outcomes following PD. Methodology: A systematic search of PubMed, Embase, Scopus, and Cochrane CENTRAL was performed up to October 15, 2025, for studies reporting microbiologically confirmed biliary fungal colonization in adult PD patients. Eligible studies included cohort and case-control designs reporting postoperative outcomes. Data extraction focused on infectious complications, clinically relevant postoperative pancreatic fistula (CR-POPF), overall morbidity, mortality, length of hospital stay, and antifungal therapy. Risk of bias was assessed using the Newcastle-Ottawa Scale. Results: Nine studies (seven retrospective cohorts, one prospective observational, one multicenter retrospective) including 2,626 patients were included and qualitatively synthesized. Fungal biliary colonization occurred predominantly in PBD patients, with Candida species most frequently isolated. Colonization rates ranged from 2.5% to 43%. Evidence regarding postoperative outcomes was heterogeneous: while some studies identified fungal colonization as a risk factor for surgical site infection (SSI), most studies found no independent association with SSI, CR-POPF, overall morbidity, or mortality after accounting for bacterial contamination and PBD. Antifungal therapy was used inconsistently, with limited evidence suggesting potential benefit in selected high-risk patients. Conclusions: Fungal biliary colonization is common in patients undergoing PBD, but current evidence suggests it is primarily a marker of biliary manipulation and bacterial co-contamination rather than an independent driver of postoperative morbidity or mortality. Routine antifungal prophylaxis is not supported, although targeted therapy may benefit high-risk individuals. Prospective multicenter studies with standardized microbiological assessment are needed to clarify the clinical significance of fungal colonization in PD.