[A case of the pulmonary thrombosis caused by unilateral pulmonary artery occulusion test]

A 71-year-old male, diagnosed as lung cancer, underwent unilateral pulmonary occulusion test. Through the guidewire, 7.5 Fr thermodilution catheter with occlusion balloon was introduced to the left pulmonary artery from the right internal jugular vein. Heparinized physiological saline solution was injected into the distal site of the occulusion. The occulusion time was 15 minutes. Pulmonary artery pressure and wedge pressure were within normal range. Soon after the examination, the pulmonary arteriogram (PAG) showed the defect of the branch to the lingular segment and the lower lobe. We made a diagnosis of pulmonary thrombosis. Three days after the administration of urokinase and heparin, both pulmonary perfusion scintigram and PAG exhibited the reperfusion to these areas. After the thrombolytic therapy was accomplished, antithrombin III and protein C in the serum showed within normal range. It was possible that the damage on the intima due to the thermodilution catheter or the guidewire and the following blood congestion by the pulmonary artery occulusion caused the thrombosis.