The Relative Role of Bile Bacterial Isolation on Outcome in Stent-Bearing Patients Undergoing Pancreatoduodenectomy

Background: Biliary stenting leads to antimicrobial-resistant (AMR) microorganism retrievement in bile cultures. However, the impact of intraoperative bile colonizations on post-pancreaticoduodenectomy complications remains unclear. Aims of our study were to characterize the bile flora of stented patients in comparison with postoperative cultures and to analyze whether patterns of drug resistance affected postoperative outcomes. Methods: We analyzed records from stent-bearing pancreaticoduodenectomy patients at 3 European centers. Intra- and postoperative cultures were compared and classified as multidrug sensitive (MDS), multidrug resistant (MDR), and extensively drug resistant (XDR). Thirty-day complications were graded according to international standards. Results: Out of 270 patients, intraoperative cultures were positive in 219 (81.1%) cases. In 36.7%, MDS species were isolated; in 35.9%, MDR; and in 8.5%, XDR species. A solid correspondence between the species isolated intra- and postoperatively (p < 0.001) was observed. Intraoperative MDR/XDR isolation was associated with an increased rate of surgical (p = 0.043) and infectious complications (p = 0.030), but not severe complication rate (p = 0.973). Postoperative MDR/XDR isolation was associated with higher risk of major complications (45.6% vs. 15.8%, p < 0.001), postoperative pancreatic fistula (p < 0.001), and post-pancreatectomy hemorrhage (p = 0.002). By multivariate analysis, intraoperative AMR isolation was associated with high likelihood of postoperative AMR infections. However, only in 43/121 cases, intraoperative MDR/XDR microorganisms turned into the occurrence of postoperative infections. Conclusion: Intraoperative AMR isolates do not translate into severe outcomes, despite being significantly associated with surgical and infectious complications.