Timing and characteristics of venous thromboembolism after noncancer surgery

Background: Venous thromboembolism (VTE) is a major cause of morbidity and mortality postoperatively. The use of pharmacologic prophylaxis is effective in reducing the incidence of VTE. However, the prophylaxis is often discontinued at hospital discharge, especially for those with benign disease. The implications of this practice are not known. We assessed the data from a large, ongoing registry regarding the time course of VTE and outcomes after noncancer surgery. Methods: We analyzed the RIETE (Computerized Registry on Venous Thromboembolism) registry, which includes data from consecutive patients with symptomatic confirmed VTE. In the present study, we focused on general surgical patients who had developed symptomatic postoperative VTE in the first 8 weeks after noncancer surgery. The main objective was to assess the interval between surgery and the occurrence of VTE. Additional variables included the clinical presentation associated with the event, the use of thrombosis prophylaxis, and unfavorable outcomes. Results: The data from 3296 patients were analyzed. The median time from surgery to the detection of VTE was 16 days (interquartile range, 8-30 days). Of the VTE events, 77% were detected after the first postoperative week and 27% after 4 weeks. Overall, 43.9% of the patients with VTE had received pharmacologic prophylaxis after surgery for a median of 8 days (interquartile range, 5-14 days), and three quarters of the VTE events were detected after pharmacologic prophylaxis had been discontinued. Overall, 54% of the patients with VTE had presented with pulmonary embolism. For 15% of the patients, the clinical outcome was unfavorable, including 4% who had died within 90 days. Conclusions: The risk of VTE after noncancer general surgery remains high for #2 months. More than one half of the patients had presented with symptomatic PE as the VTE event, and 15% had had unfavorable outcomes. Only 44% of these patients had received pharmacologic prophylaxis for around 1 week.