The purpose of the study is:

To estimate patients with lung cancers who will undergo surgery total haemostatic / thrombotic capacity pre, per-and postoperatively.

To investigate whether prophylactic treatment with Low Molecular Weight Heparin (LMWH) affects the patient's potential hypercoagulability.

To investigate whether there are differences in patients who will undergo Video Assisted Thorascopic Surgery (VATS) or open surgery in regards of impact of the coagulation system.

Lung cancer is a serious and very frequent disease. For those 25% of the patients who will undergo surgery, there are two different methods of operation: either open surgery (thoracotomy) or Video Assisted Thorascopic Surgery (VATS). The latter method is increasing in use.

Patients are often prescribed heparin pre- postoperatively, but it is unclear whether this prophylactic treatment is necessary, and it has never been thoroughly investigated.

When patients receive heparin there is an increased risk of bleeding.

Furthermore, it is unclear what changes occurs in the coagulation system pre, per- and postoperatively in patients undergoing surgery for lung-cancer, and hereby it is unclear whether these patients should have some sort of medical prophylactic treatment.

By using new analysis methods in terms of Thromboelastometry, Thrombin generation and thrombocyte function analysis, hereby the total coagulation profile can be characterized and hereby estimate the risk of thrombosis and bleeding. Thereby better be able to give the right treatment for these patients.

Inclusion Criteria:

• Undergo surgery for lung cancer with an expected lobectomy or bilobectomy
• The surgery shall be VATS (for patients in the group randomized to other low molecular weight heparin and no prophylactic)
• Willing to be randomized (VATS-patients)
• Over 18 years old.
• Able to give assigned informed consent
• Women should be prescribed secure anticonception.

Exclusion Criteria:

• Thromboembolic events within the last three months (both venous and arterial)
• Pregnant
• Lactating
• Treatment with anticoagulation therapy in terms of vitamin K antagonist or direct or indirect thrombin inhibitors (dabigatran, apixaban or rivaroxaban)
• Treatment with thrombocyte function inhibitors in terms of Clopidogrel, ASA (acetylsalicylic acid), prasugrel and ticagrelor, and no pause of minimum 5 days (7 days with regards of prasugrel) before surgery
• Allergy for LMWH