Association between clinically relevant antibiotic-resistant biliary colonization and liver-specific complications following perihilar cholangiocarcinoma resection

BACKGROUND: International guidelines recommend first-generation cephalosporins for preoperative antibiotic prophylaxis in patients undergoing resection for perihilar cholangiocarcinoma (pCCA). Knowledge on the resistance profile of biliary bacteria and its impact on liver-specific complications is limited. This study aimed to evaluate the biliary microbial spectrum, particularly focusing on the impact of resistant bacteria on liver-specific complications following pCCA resection. METHODS: This is a retrospective, single-center, observational study. All patients with resected pCCA at the University Hospital Frankfurt from July 2005 to December 2022 were included. The microbial spectrum was analyzed using intraoperative bile swabs. RESULTS: From 118 patients, 104 had an intraoperative bile swab taken. Microorganisms (bacteria, fungi) were detected in 89.4% of cases. 24% of the samples contained clinically relevant antibiotic-resistant bacteria, which were related with more severe postoperative bile leaks requiring relaparotomy (24% versus 8.8%, p = 0.055) and posthepatectomy liver failure (48% versus 25.3%, p = 0.031). 76.9% of the microbial isolates were resistant to in-house standard antibiotic prophylaxis with cefuroxime. CONCLUSION: Biliary colonization with clinically relevant antibiotic-resistant bacteria is associated with liver-specific complications.