Symptomatic venous thromboembolism in Asian colorectal cancer surgery patients

The occurrence of venous thromboembolism (VTE), manifesting as deep vein thrombosis (DVT) or pulmonary embolism (PE), after colorectal cancer surgery in Asian patients remains poorly characterized. The present study was designed to investigate the incidence of symptomatic VTE in Korean colorectal cancer patients following surgery, and to identify the associated risk factors.

We retrospectively analyzed data from patients who developed symptomatic VTE after colorectal cancer surgery between 2006 and 2008. Deep vein thrombosis was diagnosed with Doppler ultrasound or contrast venography, and PE was identified with lung ventilation/perfusion scans or chest computed tomography. Thromboprophylaxis, including low-molecular-weight heparin, graduated compression stockings, and intermittent pneumatic compression, was used in patients considered at high risk of VTE.

Of the 3,645 patients who underwent colorectal cancer surgery, 31 (0.85%) developed symptomatic VTE. Of those 31 patients, 23 (74.2%) had DVT, 16 (51.6%) had PE, and 8 (25.8%) had both. Two patients died from PE. Univariate analysis showed that a history of VTE, pre-existing cardiovascular disease, respiratory disease, transfusions, postoperative immobilization time, and postoperative complications were associated with VTE (p < 0.05 for each). Multivariate analysis showed that a history of VTE, pre-existing cardiovascular disease, postoperative complication, advanced cancer stage, and postoperative immobilization time were risk factors for developing symptomatic VTE. The mean hospital stay was 18.3 days, and the mortality rate was 6.5%.

The incidences of symptomatic DVT and PE were found to be not low in Asian colorectal cancer surgery patients compared with Western countries. The risk factors for VTE were a history of VTE, pre-existing cardiovascular disease, postoperative complications, advanced cancer stage, and postoperative immobilization. Thromboprophylaxis should be strongly considered in patients with these characteristics. Large prospective randomized controlled trials should be conducted to further evaluate the risk of VTE in Asian patients, and to determine the optimal prophylaxis.