Postoperative venous thromboembolism (VTE) is a significant health-care problem, resulting in significant morbidity, mortality and resource utilization. The true incidence is unknown, and may range from 1% to 15%. At the current time, the clinical practice of VTE prophylaxis in thoracic surgery includes administration of unfractionated or low molecular weight heparin starting at the perioperative period and finishing at the time of patients' discharge. In orthopaedic surgery, prolonged thromboprophylaxis beyond 10 days and up to 35 days has become the standard of care. There is a clear need to systematically evaluate the incidence of VTE after resection of lung malignancies and to evaluate the role of extended VTE prophylaxis in preventing Deep Vein Thrombosis (DVT) and pulmonary embolus (PE) after those major lung resections. This study will involve patients undergoing lung resection for malignancy at St. Joseph's Healthcare Hamilton and the University Health Network's Toronto General Hospital. The study will include 150 consecutively recruited patients. Study interventions will include Computed Tomography with pulmonary embolus (PE) protocol and bilateral extended leg Doppler Ultrasound for the detection of Deep Vein Thrombosis 30 days post-surgery.