Is venous thromboembolism in colorectal surgery patients preventable or inevitable? One institution's experience

Background: The rate of venous thromboembolism (VTE) in colorectal surgery patients is reportedly high. Herein, we describe characteristics of patients developing VTE in the early postoperative period.

Study design: A retrospective cohort analysis was conducted using institutional comprehensive data on colorectal surgery patients from the National Surgical Quality Improvement Program. All patients from July 2009 to July 2011 were included. Multivariable logistic regression was used to assess which factors were associated with increased risk of developing VTE within 30 days of operation.

Results: There were 615 patients who underwent colorectal surgery. Twenty-five (4.1%) developed VTE; 16 (2.6%) deep venous thrombosis (DVT), 4 (0.7%) pulmonary embolus (PE), and 5 (0.8%) developed both DVT and PE. Among VTE patients, 23 (92%) were ordered risk-appropriate VTE prophylaxis. On multivariable analysis, risk factors associated with VTE included postoperative infection (odds ratio [OR] 4.21, 95% CI 1.79, 9.89; p = 0.001), disseminated cancer (OR 4.38, 95% CI 1.24, 15.42; p = 0.022), and emergent status (OR 2.80, 95% CI 1.15, 6.85; p = 0.024). Fourteen (56.0%) of the 25 VTE patients also developed infectious complications compared with 168 (28.5%) of patients without VTE (p = 0.001). Organ space surgical site infections were the most common infection, present in 7 VTE patients. The infectious complications in 9 (64.3%) of the 14 patients occurred before or the same day as the VTE.

Conclusions: Most VTE events occurred in colorectal surgery patients ordered current best practice prophylaxis for VTE. Further investigation is warranted to identify patients at increased risk for VTE and to develop new strategies to further reduce the incidence of postoperative VTE.