PURPOSE: Venous thromboembolism (VTE) is an important complication of neurosurgery. Current guidelines recommend pharmacologic prophylaxis in this setting with either unfractionated heparin (UFH) or low-molecular weight heparin (LMWH). The quality and the extent of the literature supporting this recommendation are unclear.
METHODS: We conducted a systematic review and meta-analysis exploring the role for prophylactic heparin following neurosurgery. We searched multiple databases (MEDLINE, PUBMED, Cochrane RCT, Embase, Biosis, PASCAL, Sci Search) to identify prospective trials reporting on VTE prevention (either mechanical or pharmacologic). Rates of VTE and bleeding served as our primary endpoints.
RESULTS: We identified 25 studies reporting on 7293 patients. There was significant heterogeneity in pharmacologic agent dosing and timing, outcome assessments, and comparator group across these trials limiting our ability to pool data. We were able to perform a quantitative meta-analysis of 5 trials evaluating the safety and efficacy of LMWH vs. a non-pharmacologic approach. LMWH was associated with a reduced rate of deep vein thrombosis (OR: 0.55; 95% CI 0.39-0.77) but did not impact the frequency of pulmonary embolism (OR: 0.60; 95% CI: 0.22-1.63). LMWH did not appear to increase the risk for either major bleeding (OR: 2.00; 95% CI: 0.82-4.86) or intracranial hemorrhage (OR: 2.11; 95% CI: 0.82-5.43). There were only two well-designed studies using unfractionated heparin (UFH), and these trials were too small to allow one to draw conclusions.
CONCLUSION: There are few well done trials exploring pharmacologic VTE prevention in neurosurgery. LMWHs reduce the risk for VTE following neurosurgery without increasing the risk for clinical bleeding. However, the quality of the studies examining LMWH is limited. There is scant data regarding either the safety or efficacy of UFH in neurosurgery.
CLINICAL IMPLICATIONS: Although current guidelines recommend the use of UFH or LMWH when chemical prophylaxis is used, there is a higher level of evidence in favor or LMWH. Given the limited data, decisions regarding choice of agent must be individualized.
DISCLOSURE: Jacob Collen, No Financial Disclosure Information; No Product/Research Disclosure Information