A direct comparison of prophylactic low-molecular-weight heparin versus unfractionated heparin in neurosurgery: A meta-analysis

BACKGROUND: Several studies have confirmed the role of prophylactic low-molecular-weight heparin (LMWH) for venous thromboembolism (VTE) in neurosurgery; however, a paucity of literature has assessed its safety and efficacy versus prophylactic unfractionated heparin (UFH). The objective is to present a meta-analysis directly comparing prophylactic LMWH to UFH for the prevention of VTE in neurosurgery. MATERIALS AND METHODS: Relevant studies that directly compared LMWH to UFH for prophylaxis of VTE in neurosurgery and/or spine surgery were identified by MEDLINE and EMBASE searches plus a scrutiny of references from the original articles and reviews. Three randomized trials were included in the meta-analysis. Efficacy and safety were ascertained per three primary outcome measures: VTE, minor complications (decline in hemoglobin/hematocrit), and major complications. Forest plot analysis provided odds ratio (OR), 95% confidence intervals (CIs), and P-values. RESULTS: Of the 429 patients in the pooled analysis, the postoperative VTE rate of 5.6% (12/213) after LMWH chemoprophylaxis was equivalent to 3.7% (8/216) after UFH chemoprophylaxis (OR = 1.42, 95% CI 0.62–3.75, P = 0.308). Minor complications of 4.7% versus 4.6%, respectively, were nearly equal (OR = 1.01, 95% CI 0.41– 2.50, P = 0.929). All four major complications included intracranial hemorrhages: three after LMWH (1.4%) and one after UFH (0.5%) (OR = 2.32, 95% CI 0.34–16.01, P = 0.831). Tests for heterogeneity were nonsignificant in all three outcome measures. CONCLUSION: Rates of VTE, minor complications, and major complications were equivalent between prophylactic LMWH and UFH in neurosurgery. Further, randomized clinical trials comparing the two heparin products are required to elucidate superior safety and efficacy in neurosurgical patients.