OBJECTIVES: Postoperative thromboembolism is a serious complication, but the incidence following surgery for lung cancer appears to be much lower compared with other surgical specialties. The reason is unknown and one may speculate that the lungs are reservoirs of anticoagulants or fibrinolytic substances, which are released by manipulation of the lung parenchyma during surgery.
METHODS: Standardized lung manipulation, single-lung ventilation and pneumonectomy were performed in 10 anaesthetized pigs. Baseline and serial postmanipulation intravenous and intra-arterial blood samples were analysed for a wide range of fibrinolytic substances as well as pro- and anticoagulant factors.
RESULTS: We found a transient but significant decrease in activated partial thromboplastin time (aPTT) and plasminogen activator inhibitor following manipulation of the lungs. Pneumonectomy resulted in minor but significant decrease in antithrombin and a significant increase in aPTT. All other measured substances were virtually constant.
CONCLUSIONS: A wide range of fibrinolytic and anticoagulant substances remained unchanged during experimental lung manipulation. Minor changes were transient and not considered clinically relevant. Future studies should be initiated in humans because we have no deeper understanding why thromboembolic complications are relatively uncommon after general thoracic surgery compared with other surgical specialties.