The pivotal predictor of severe postoperative complications of pancreatoduodenectomy: complex links of bacterial contamination from preoperative biliary drainage.

Preoperative biliary drainage (PBD) prior to pancreatoduodenectomy (PD) is controversial. The aim of this study was to clarify how PBD leads to postoperative complications of PD. The subjects of this retrospective study were 230 patients who underwent PD between January, 2008 and January, 2018. We analyzed how PBD was associated with severe postoperative complications (Clavien-Dindo ≥ IIIB) with special reference to its links with bacterial contamination. Preoperative biliary drainage (PBD) was correlated with the contamination of both bile juice collected at surgery (p < 0.001) and ascites collected from the intraperitoneal drain on postoperative day (POD) 3 (p < 0.001). Receiver operating characteristic curve analysis revealed that PBD for longer than 28 days was significantly associated with the contamination of bile juice. Multivariate regression analysis revealed that the contamination of ascites on POD3 was independently associated with severe postoperative complications (Clavien-Dindo ≥ IIIB) (odds ratio 3.52, p = 0.03), although PBD and the contaminated bile juice at surgery were not. PBD was associated with the contamination of biliary tract and ascites after surgery. The current study revealed that contaminated ascites on POD 3, not PBD by itself, was independently associated with severe postoperative complications after PD.