Efficacy of different types of chemoprophylaxis for venous thromboembolism in elective spine surgery: A network meta-analysis of randomized controlled trials

Background: The purpose of this study was to comprehensively examine the high-level evidence regarding the efficacy and safety of chemoprophylaxis for venous thromboembolism (VTE) for adults in elective spine surgery. Methods: A pre-registered network meta-analysis (NMA) (PROSPERO: CRD420251026334) used four databases searched through April 2025 to identify randomized controlled trials (RCTs) that examined various types of VTE chemoprophylaxis for adults in elective spine surgery. Exclusion criteria were non-randomized studies and non-elective spine surgery. This study utilized a random-effects Bayesian NMA model using risk ratio (RR) with 95% confidence intervals and surface under the cumulative ranking curve (SUCRA) for comparisons. Certainty of evidence, risk of bias, and network model transitivity were also assessed. Results: Twelve RCTs were included. Patients (n = 3159; mean age = 54.5 years; mean operative time = 169.0 min) were stratified into one of eight subgroups: direct oral anticoagulant (DOAC; n = 715), low-molecular-weight heparin (LMWH) (n = 814), heparin (n = 117), aspirin (n = 91), tranexamic acid (TXA; n = 363), TXA and DOAC (n = 387), warfarin (n = 35), or no chemoprophylaxis (n = 637) based on the chemoprophylaxis method received. For effectiveness, all chemoprophylactic groups demonstrated an absolute decrease in VTE and DVT incidence compared to the no chemoprophylaxis group; however, no group had a high probability (≥75%) of being the best or worst treatment, indicating no clear evidence of superiority. For safety, all subgroups demonstrated a similar incidence of significant bleeding events and epidural hematoma with no group having a high probability (≥75%) of being the best or worst treatment, indicating no clear evidence of superiority. Rates of epidural hematoma ranged from 0 to 0.56% in all studies. Certainty of evidence was "moderate" for VTE effectiveness and "low" for chemoprophylactic safety. Conclusion: Various types of VTE chemoprophylaxis in elective spine surgery may be clinically equivocal for effectiveness and safety, with no method demonstrating a high probability of superiority. VTE chemoprophylaxis should be used on a case-by-case basis factoring in individual patient variables.