Effect of thromboprophylaxis on the incidence of venous thromboembolism in surgical patients with colorectal cancer: a meta-analysis.

Abstract

This study evaluates the role of thromboprophylaxis in venous thromboembolism (VTE) incidence in colorectal cancer (CRC) surgical patients. Literature search was conducted in electronic databases and studies (randomized controlled trials, or prospective/retrospective cohorts) were selected if they reported the incidence of VTE in CRC patients who underwent any type of open or laparoscopic surgery. Random-effects meta-analyses were performed to obtain pooled incidence estimates; or odds ratios (OR) of incidence between prophylaxis and no-prophylaxis groups; or between VTE and non-VTE patients to identify risk factors. Twenty-four studies (804,003 patients) were included. Prophylaxis was performed mainly with low molecular weight heparins. Odds of VTE were significantly lower in prophylactic than in non-prophylactic patients (OR 0.42 [95% CI: 0.28, 0.63]; P<0.00001). Incidence of radiological and symptomatic VTE in patients with prophylaxis was 9.7% [95% CI: 8.6, 10.8] and 1.3% [95% CI: 0.7, 2.0] respectively. Odds of bleeding were higher in patients with prophylaxis (OR: 3.37 [95% CI: 1.05, 10.8]; P=0.04). Incidence of bleeding in patients with and without prophylaxis was 4.3% [95% CI: 3.2, 5.4] and 1.2% [95% CI: 0.02, 2.4] respectively. Operative time, anesthesia duration, and hospital stay were longer in patients with VTE. Obesity, disseminated cancer, chemotherapy, steroid use, emergency case status, advanced stage cancer, hypoalbuminemia, postoperative infection/sepsis, and history of VTE are identified as important risk factors for VTE incidence. Thromboprophylaxis reduces the incidence of VTE in CRC surgical patients but may increase the chances of bleeding. Several risk factors can influence VTE incidence.