Background: Patients undergoing bariatric surgery are at an increased risk of venous thromboembolic events (VTE). The optimal low-molecular weight heparin (LMWH) thromboprophylactic dosing is debated. Different dosing regimens have reported bleeding and VTE rates ranging between 0% to 6.4% and 0% to 6.7%, respectively.
Aims: We sought to analyze the safety and efficacy of different thromboprophylactic regimens using LMWH following bariatric surgery.
Methods: We conducted a search of Medline and Embase from inception until November 2020. Screening and data abstraction were independently done by two authors (GL and JD). Observational studies or randomized controlled trials that assessed thromboprophylaxis using LMWH following bariatric surgery were included. LMWH regimens group by duration (<10-days or ≥10-days of anticoagulation and were classified as either weight-adjusted or non-weight adjusted, with non-weight adjusted doses grouped using the ASH classification of anticoagulant regimens (Table 1). The primary efficacy and safety outcomes were bleeding and VTE, respectively, and analyzed with the help of a biostatistician using the Comprehensive Meta-Analysis Software.
Prophylactic Regimen | Intermediate Regimen |
Bemiparin 3500 U, SC OD Dalteparin 5000 U, SC OD Enoxaparin 30 mg (3000 U), SC OD (for GFR 15-30) Enoxaparin 30 mg (3000 U), SC BID (for BMI ≥40 kg/m2) Enoxaparin 40 mg (4000 U), SC OD Enoxaparin 40 mg (4000 U), SC BID (for BMI ≥40 kg/m2) Unfractionated heparin 5000 U, SC BID Unfractionated heparin 5000 U, SC TID Unfractionated heparin 7500 U, SC BID (for BMI ≥40 kg/m2) Nadroparin 2850 U, SC q24h (post-op general surgery) Nadroparin 5700 U, SC q24h (high-risk medical patients >70 kg) Nadroparin 3800 U, SC q24h (high-risk medical patients ≤70 kg or post-op hip replacement surgery Tinzaparin 3500 U, SC OD Tinzaparin 4500 U, SC OD Tinzaparin 75 U/kg, SC OD |
Enoxaparin 0.5 mg/kg (50 U/kg), SC BID (if CrCl >30 mL/min) Enoxaparin 0.5 mg/kg (50 U/kg), SC OD (if CrCl <30 mL/min) Enoxaparin 30 mg (3000 U), SC BID (for BMI <40 kg/m2) Enoxaparin 40 mg (4000 U), SC BID (for CrCl >30 mL/min and BMI <40 kg/m2) Enoxaparin 60 mg (6000 U), SC BID (for CrCl >30 mL/min and BMI >40 kg/m2) Unfractionated heparin 7500 U, SC TID Dalteparin 5000 U, SC BID |
Results: Out of the 2692 studies identified by our search, a total of 41 articles were included. The majority of studies were observational cohort studies with enoxaparin being the most common LMWH. The rates of bleeding and VTE are reported in Figure 2. The rate of VTE ranged from 0.5% to 2% for <10-day regimens and 0.6% to 1.1% for ≥10-day regimens. The rate of bleeding ranged from 1.5% to 3.1% for <10-day regimens and 2.4% to 3% for ≥10-day regimens. The overall degree of heterogeneity was moderate for VTE and high for bleeding.
Conclusions: There was no statistically significant difference in terms of the VTE and bleeding rate between the different regimes of LMWH. The heterogeneity of the data calls for prospective studies using standardized measurements of VTE and bleeding for further clarification.
To cite this abstract in AMA style:
Li A, Eshaghpour A, Lee G, Deng J, Ikesaka R, Carrier M, Crowther M. Safety and Efficacy of Low-Molecular Weight Heparin Regimes for Venous Thromboembolism Prophylaxis in Bariatric Surgery [abstract]. Res Pract Thromb Haemost. 2021; 5 (Suppl 2). https://abstracts.isth.org/abstract/safety-and-efficacy-of-low-molecular-weight-heparin-regimes-for-venous-thromboembolism-prophylaxis-in-bariatric-surgery/. Accessed March 22, 2024.« Back to ISTH 2021 Congress
ISTH Congress Abstracts - https://abstracts.isth.org/abstract/safety-and-efficacy-of-low-molecular-weight-heparin-regimes-for-venous-thromboembolism-prophylaxis-in-bariatric-surgery/