BACKGROUND: Pancreatic head resection is associated with postoperative morbidity, primarily because of infectious complications. The microbiota in these infections is crucial, and selective decontamination of the digestive tract (SDD) aims to mitigate this risk by targeting pathogenic organisms while preserving beneficial flora. This study aimed to determine the effect of SDD on bacterial shifts and resistance patterns in pancreatic head resection.

METHODS: All patients who underwent pancreatic head resection either between January 2012 and August 2018 (non-SDD group) or between January 2019 and December 2021 (SDD group) were included. Propensity score-matched analysis was performed to compare the bacterial presence and resistance patterns in bile duct smear tests and postoperative complications.

RESULTS: Positive bile duct smear tests were observed more often in the non-SDD group (63.5%) than in the SDD group (51.0%). Moreover, the SDD group exhibited a significant reduction in the median number of bacterial species in the bile ducts compared with the non-SDD group (P = .04). However, a notable increase in gram-negative species was observed in the SDD group. The SDD group experienced higher rates of postoperative complications, including relevant pancreatic fistulas (24.8% in the SDD group vs 11.6% in the non-SDD group; P < .01) and delayed gastric emptying (33.8% in the SDD group vs 21.9% in the non-SDD group; P < .01). No significant difference in antibiotic resistance patterns was observed.

CONCLUSION: SDD in pancreatic head resection reduces bacterial load in the biliary tract, but it is associated with a shift toward more gram-negative species and higher rates of severe postoperative complications. Our findings suggest that SDD may negatively affect postoperative outcomes and should be carefully considered in clinical practice.