Biliary Tract Instrumentations Prior to Elective Cholecystectomy: Effect on Biliary Microbiome

Background: Calculus biliary disease is a common condition that requires invasive procedures in complicated cases. The effect of biliary instrumentation on the biliary microbiome and its impact on surgical complications after elective cholecystectomy remains unclear. This study aimed to assess the impact of prior biliary instrumentation on the biliary microbiome, as well as on the clinical outcomes of cholecystectomy. Patients and Methods: This retrospective study included all patients who underwent elective cholecystectomy for calculus biliary disease between 2015 and 2020 in a single medical center. Data regarding biliary instrumentation prior to cholecystectomy, biliary cultures obtained during cholecystectomy, and clinical outcomes were collected. A comparison between patients with and without prior instrumentation was performed with regard to biliary cultures and clinical outcomes. Results: Of the 508 patients studied, 109 patients underwent biliary instrumentation prior to cholecystectomy. Patients with prior instrumentation were older and more likely to be men (p < 0.0001). Prior instrumentation was also associated with higher rates of conversion to open surgery (p < 0.0001). Positive biliary cultures and polymicrobial growth were both more common among patients with prior instrumentation (p < 0.0001). Prior instrumentation was associated with longer length of hospital stay, as well as higher rates of perioperative complications and surgical site infection (p < 0.0001). Conclusions: Prior instrumentation was associated with poorer clinical outcomes and affected the biliary microbiome. The different results of biliary cultures in these patients may suggest that an alternative empiric antibiotic regimen should be considered when treating patients with biliary instrumentation.