Prevention of venous thromboembolism in neurosurgery: a metaanalysis.

BACKGROUND Venous thromboembolism (VTE) is an important complication of neurosurgery. Current guidelines recommend pharmacologic prophylaxis in this setting with either unfractionated heparin or low-molecular-weight heparin (LMWH). We conducted a systematic review asking, "Among patients undergoing neurosurgical procedures, how safe and effective is the prophylactic use of heparin and mechanical devices?" METHODS We searched the medical literature to identify prospective trials reporting on VTE prevention (either mechanical or pharmacologic). The rates of VTE and bleeding were our primary end points and were pooled using a random-effects model. RESULTS We identified 30 studies reporting on 7,779 patients. There were 18 randomized controlled trials and 12 cohort studies. The results of pooled relative risks (RRs) showed LMWH and intermittent compression devices (ICDs) to be effective in reducing the rate of deep vein thrombosis (LMWH: RR, 0.60; 95% confidence interval [CI], 0.44 to 0.81; ICD: RR, 0.41; 95% CI, 0.21 to 0.78). Similar results were seen when pooled rates from all 30 trials were analyzed. In head-to-head trials, there was no statistical difference in the rate of intracranial hemorrhage (ICH) between therapy with LMWH and nonpharmacologic methods (RR, 1.97; 95% CI, 0.64 to 6.09). The pooled rates of ICH and minor bleeding were generally higher with heparin therapy than with non-heparin-based prophylactic modalities. CONCLUSIONS In a mixed neurosurgical population, LMWH and ICDs are both effective in the prevention of VTE. Sensitivity analyses have suggested that isolated high-risk groups, such as those with patients undergoing craniotomy for neoplasm, may benefit from a combination of prophylactic methods, suggesting the need for a more individualized approach to these patients.