[Risk Factors Associated with Venous Thromboembolism after Lung Cancer Surgery: A Single-center Study]

The Previous study has indicated that the incidence of venous thromboembolism (VTE) after lung cancer surgery is not uncommon. The aim of this study is to analyze the risk factors of postoperative VTE in lung cancer patients and provide a clinical basis for further prevention and treatment of VTE.

This study was a single-center study. From July 2016 to December 2017, all patients with lung cancer who underwent surgery in our department were enrolled into this study. Except routine preoperative examinations, lower extremity Doppler ultrasound was performed in all patients before and after surgery to determine whether there was any newly developed deep venous thrombosis (DVT). Patients did not receive any prophylactic anticoagulant therapy before and after surgery. Patients were then divided into VTE group and control group according to whether VTE occurred after operation. Baseline data, surgical related data (surgery type, surgical procedure, etc.) and tumor pathological data (pathological type, vascular infiltration, pathological staging, etc.) were compared between the two groups.

According to the inclusion criteria, a total of 339 patients undergoing lung cancer surgery were analyzed. There were 166 males and 173 females with an age range of 23-86 years. A total of 39 patients developed VTE after surgery, the incidence rate of postoperative VTE was 11.5%. Comparing the age, gender, body mass index (BMI), American Society of Anesthesiologists (ASA), smoking status, underlying diseases, etc, there were no significant differences in other indicators except for significant differences in age; comparison between preoperative blood routine, blood biochemistry, coagulation, tumor markers, lung function, lower extremity venous ultrasound, preoperative carcinoembryonic antigen (CEA) levels, preoperative D-dimer levels, there were significant differences in lung function and lower extremity intermuscular vein expansion ratio. There were no significant differences in other indexes between the two groups. The duration of surgery, surgical procedure, bleeding volume, pathological type, pathological stage, vascular invasion, were compared between the two groups. There were statistical differences in surgical methods (thoracic vs thoracoscopic) and bleeding volume. There were no significant differences in other indicators. Univariate analysis showed that age, preoperative CEA level, preoperative D-dimer level, poor pulmonary function, lower extremity intermuscular vein dilation ratio, thoracotomy rate, length of surgery, and amount of bleeding were significantly risk factors (P<0.05). There were no significant correlations between pathological stage and pathological type and VTE. Multivariate logistic regression analysis showed that forced expiratory volume in one second (FEV1), surgical approach, and lower extremity intermuscular vein dilatation were independent risk factors for postoperative VTE in patients with lung cancer (P<0.05).

The results of this study suggest that FEV1, surgical procedures, and lower extremity intermuscular vein dilation are independent risk factors for postoperative VTE in patients with lung cancer.