Predictors of Venous Thromboembolism after Colorectal Surgery in a Single Unit.

Background: Patients undergoing colorectal surgery are at risk of developing venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE). Knowing predictors of VTE could help preventing this life-threatening complication.

Methods: We collected data of patients undergoing colorectal surgery at our Unit between 2009 and 2014. Baseline characteristics, type of surgery, and postoperative complications were gathered. A univariate regression analysis was performed with symptomatic VTE as outcome. Pre-, intra- and postoperative clinical factors were separately tested. All variables significantly associated with VTE occurring within three months from the discharge were entered in the final multivariate regression model.

Results: A total of 476 patients were included. Symptomatic VTE occurred in 13 patients (2.7%). Six (46.1%) occurred after hospital discharge. Preoperative variables associated with VTE were: advanced age at surgery (OR 2.3, 95%CI 1.8-5.6), smoking (OR 1.7, 95%CI 1.2-2.5), inflammatory bowel diseases (OR 2.1, 95%CI 1.5-4.3), advanced pelvic malignancies (OR 2.4, 95%CI 2.0-4.2), and obesity (OR 1.5, 95%CI 1.1-2.1). Prolonged pelvic manipulation (OR 1.8, 95%CI 1.1-4.3) and steep Trendelenburg position (OR 2.4, 95%CI 1.9-5.0) were intraoperative predictors of VTE, while stockings significantly reduced the risk (OR 0.8, 95%CI 0.4-0.9). Late mobilization (OR 2.5, 95%CI 2.0-4.6) and septic complications (OR 1.4, 95%CI 1.2-3.7) were postoperative predictors of VTE, whereas anticoagulants administered for at least 3 weeks after discharge were associated with lower VTE risk (OR 0.5, 95%CI 0.2-0.8).

Conclusions: We observed several modifiable predictors of VTE. Patients with ≥2 risk factors undergoing colorectal surgery could benefit from a more intensive VTE preventive pathway.