Background: The optimal timing and type of pharmacological venous thromboembolic prophylaxis (VTEp) after severe liver injury selected for nonoperative management (NOM) are controversial. The aim of this study was to assess the effect of timing and type of VTEp in severe liver injuries selected for NOM.
Methods: ACS-TQIP database study (2013-17) including patients with blunt isolated severe liver injuries (AIS ≥ 3), selected for NOM, who received VTEp with either unfractionated heparin (UH) or low-molecular-weight heparin (LMWH). Patients who underwent laparotomy or angiointervention within 24 h or prior to the initiation of VTEp were excluded. The study population was stratified according to the timing of VTEp ≤ 48 h (EP) and > 48 h (LP) groups. Univariate and multivariate analyses were used to identify differences between the groups.
Results: A total of 4074 patients was included in the study. 2004 (49.2%) received EP and 2070 (50.8%) LP. Patients with more severe injuries were more likely to receive LP than an EP [ISS 24 (19-29) vs 22 (17-27), p < 0.001]. On multivariate analysis (correcting for age, gender, comorbidities, blood pressure, GCS, ISS, type of VTEp), LP was identified as an independent risk factor for thromboembolic events (OR 1.52, p = 0.032) and mortality (OR 2.49, p = 0.031). LMWH was independently associated with lower mortality (OR 0.36, p = 0.007), compared to UH. EP did not increase the risk of laparotomy or angiointervention after starting VTEp, compared to LP (p = 0.992).
Conclusion: Early VTEp (≤ 48 h) is safe and independently associated with fewer thromboembolic events and a lower mortality after isolated severe liver injuries managed nonoperatively. LMWH was independently associated with improved outcomes when compared with UH.