Meta-analysis of randomized trials comparing combined compression and anticoagulation with either modality alone for prevention of venous thromboembolism after surgery

Background: Although venous thromboembolism (VTE) is an important cause of postoperative morbidity and mortality, there is still no consensus on the optimal strategy for VTE prevention after major surgery. The objective of this review was to determine the benefits and risks of thromboprophylaxis with both compression and anticoagulation, compared with either modality alone. Methods: A systematic review of MEDLINE, CENTRAL and Embase databases was performed to identify eligible randomized trials. The literature search and data extraction were carried out independently by two reviewers. Outcomes of interest were deep vein thrombosis (DVT), pulmonary embolism, bleeding, limb injury and mortality. Results: Twenty-five studies were eligible for inclusion. Adding compression to anticoagulation decreased the risk of DVT by 49 per cent (risk ratio (RR) 0.51, 95 per cent confidence interval 0.36 to 0.73). The corresponding funnel plot suggested publication bias and, overall, the evidence for this comparison was judged to be of low quality. Adding anticoagulation to compression decreased the risk of DVT by 44 per cent (RR 0.56, 0.45 to 0.69) while increasing the risk of bleeding (RR 1.74, 1.29 to 2.34). There was no suggestion of publication bias and the evidence for this comparison was judged to be of moderate quality. Conclusion: Combined compression and anticoagulation is more effective at preventing postoperative DVT than either modality alone. However, adding anticoagulation to compression increases the risk of bleeding, and the evidence that adding compression to anticoagulation reduces VTE risk is of low quality.