Clinical usefulness of routinely performed drain fluid cultures after pancreaticoduodenectomy. A new ally to predict patients’ outcomes?

Background: Previous studies showed that bacterial contamination of surgical drains was associated with higher morbidity and mortality following pancreaticoduodenectomy (PD). However, there is still no agreement on the routine use of fluid drainage cultures in the management of patients underwent PD. Therefore, we aimed to clarify the role of surgical drain bacterial contamination in predicting patients' postoperative course. Method: Single-centre study including patients underwent PD at Humanitas Research Hospital (2010-2021). Preoperative, intraoperative and postoperative data were collected. Routinely performed fluid drain cultures on postoperative day (POD) 5 were analyzed and compared among patients throughout the cohort. Results: A total of 825 patients were analyzed. Bacterial contamination of surgical drains was observed in 420 (50.9 %) patients and it was found to be associated with a higher rate of B/C grade pancreatic fistula (POPF) (P < 0.001), Clavien-Dindo≥3 (P < 0.001), 30-day mortality (P = 0.011), wound infection (P < 0.001), relaparotomies (P = 0.003) and greater length of hospital stay (LOS) (P < 0.001). Also, E. coli surgical drain contamination was demonstrated to double the risk of B/C grade POPF development (OR = 1.628, 95 % IC = 1.009-2.625, P = 0.046). Finally, preoperative biliary drainage (OR = 2.474, 95 % IC = 1.855-3.298, P < 0.001), age ≥75 years old (OR = 1.492, 95 % IC = 1.077-2.067, P = 0.016) and isolated Roux-en-Y pancreaticojejunostomy (OR = 1.639, 95 % IC = 1.229-2.188, P < 0.001) were identified as risk factors for surgical drains bacterial contamination. Conclusion: Bacterial contamination of surgical drains predicts the development of B/C grade POPF and other major complications after PD. Therefore, we suggest the routine use of fluid drain cultures following PD.