Combined intermittent pneumatic leg compression and pharmacological prophylaxis for prevention of venous thromboembolism in high-risk patients.

BACKGROUND It has been suggested that combined modalities (methods of treatment) are more effective than single modalities in preventing venous thromboembolism (defined as deep vein thrombosis and pulmonary embolism, or both) in high-risk patients. OBJECTIVES To assess the efficacy of intermittent pneumatic leg compression combined with pharmacological prophylaxis versus single modalities in preventing venous thromboembolism in high-risk patients. SEARCH STRATEGY The Cochrane Peripheral Vascular Diseases (PVD) Group searched their Specialized Register (last searched 17 July 2007) and the Cochrane Central Register of Controlled Trials (CENTRAL) (last searched The Cochrane Library 2008, Issue 3). We searched the reference lists of relevant articles to identify additional trials. SELECTION CRITERIA Randomized controlled trials (RCTs) or controlled clinical trials (CCTs) of combined intermittent pneumatic leg compression and pharmacological interventions used to prevent venous thromboembolism in high-risk patients. DATA COLLECTION AND ANALYSIS Data extraction was undertaken independently by two review authors using data extraction sheets. MAIN RESULTS Eleven studies, six of them randomized controlled trials, were identified. The trials included 7431 patients, in total. Compared with compression alone, the use of combined modalities reduced significantly the incidence of both symptomatic pulmonary embolism (PE) (from about 3% to 1%; odds ratio (OR) 0.39, 95% confidence interval (CI) 0.25 to 0.63) and deep vein thrombosis (DVT) (from about 4% to 1%; OR 0.43, 95% CI 0.24 to 0.76). Compared with pharmacological prophylaxis alone, the use of combined modalities significantly reduced the incidence of DVT (from 4.21% to 0.65%; OR 0.16, 95% CI 0.07 to 0.34) but the included studies were underpowered with regard to PE. The comparison of compression plus pharmacological prophylaxis versus compression plus aspirin showed a non-significant reduction in PE and DVT in favor of the former group. Repeat analysis restricted to the RCTs confirmed the above findings. AUTHORS' CONCLUSIONS Compared with compression alone, combined prophylactic modalities decrease significantly the incidence of venous thromboembolism. Compared with pharmacological prophylaxis alone, combined modalities reduce significantly the incidence of DVT but the effect on PE is unknown. The results of the current review support, especially in high-risk patients, the use of combined modalities. More studies on their role in PE prevention, compared with pharmacological prophylaxis alone, are urgently needed.