Rate of prophylactic anti-Xa achievement and impact on venous thromboembolism following oncologic hepato-pancreatico-biliary surgery: A prospective cohort study

Published:December 02, 2022DOI:


      • Current LMWH regimens place HPB patients at risk of subprophylactic Anti-Xa levels.
      • Subprophylactic anti-Xa levels are associated with increased risk of VTE.
      • In HPB patients, tinzaparin has increased rate of subprophylactic anti-Xa levels.



      Hepato-pancreatico-biliary (HPB) patients experience competing risk of venous thromboembolism (VTE) and bleeding. We sought to evaluate the effect of anti-Xa levels on VTE and bleeding, and to characterize factors associated with subprophylaxis.


      This prospective cohort study evaluated adult HPB surgical patients; cohorts were described by anti-Xa levels as subprophylactic (<0.2 IU/mL), prophylactic (0.2–0.5 IU/mL), and supraprophylactic (>0.5 IU/mL). Primary outcome evaluated bleeding and VTE complications. Secondary outcomes evaluated factors associated with subprophylaxis.


      We included 157 patients: 68 (43.6%) attained prophylactic anti-Xa and 89 (56.7%) were subprophylactic. Subprophylactic patients experienced more VTE compared to prophylactic patients (6.9% vs 0%; p = 0.028) without differences in bleeding complications (14.6% vs 5.9%; p = 0.081). Factors associated with subprophylactic anti-Xa included female sex (OR 2.90, p = 0.008), and Caprini score (OR 1.30, p = 0.035). Enoxaparin was protective against subprophylaxis compared to tinzaparin (OR 0.43, p = 0.029).


      Many HPB patients have subprophylactic anti-Xa levels, placing them at risk of VTE. Enoxaparin may be preferential, however, studies evaluating optimized prophylaxis are needed.

      Graphical abstract


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