ObjectiveTo evaluate efficacy and safety of early anticoagulation therapy with low molecular weight heparin (LMWH) in prevention of venous thromboembolism (VTE) after pancreatoduodenectomy (PD).MethodsThe patients who received PD in our hospital from January 2017 to December 2018 were collected retrospectively, then were divided into the anticoagulant group and the non-anticoagulant group. The operation time, intraoperative blood loss, tumor property, coagulation function indexes such as prothrombin time (PT), PT activity (PTA), fibrinogen (FIB), activated partial thromboplastin time (APTT), thrombin time (TT), and D-dimer (DD), platelet (PLT), VTE, bleeding related complications etc. were compared between the two groups.ResultsA total of 103 patients underwent PD were included in this study, including 52 patients in the anticoagulant group and 51 patients in the non-anticoagulant group. There were no significant differences in the baseline data such as the gender, age, and preoperative coagulation function indexes, etc. between the two groups (P>0.05). The incidence of VTE in the anticoagulant group was lower than that in the non-anticoagulant group (13.5% versus 47.1%, P<0.001). There was no significant difference in the incidence of bleeding between the anticoagulant group and the non-anticoagulant group (9.6% versus 7.8%, P>0.05). There were no statistically significant differences in the coagulation indexes between the two groups before operation and day 1 after operation (P>0.05). On day 8 after operation, the FIB and DD values of the anticoagulant group were significantly lower than those of the non-anticoagulant group (P values were 0.040 and 0.002, respectively). A comparison of different phases in the same group on coagulation indexes between day 8 and day 1 after surgery showed that there were statistically significant differences (P<0.05), the changes of all indexes were within the normal range.ConclusionThe results of this study indicate that LMWH administered at 24 h after PD could decrease incidence of VTE and don’t increase risk of bleeding.