RESUMO
In vascular surgery, thrombo-embolism and hemorrhage are major noisome complications. We report a case of cholesterol emboli which came from atheromatous aortic wall during the thoracoabdominal aortic aneurysm operation. Micro-emboli were migrated into the capillary in the liver, kidney and small bowels, and the patient died of multiple organ failure. The histological examination showed the cholesterol emboli in micro-circulations. The other is a case of <i>in situ</i> thrombus formation in the posterior tibial artery during aortic surgery. The patient with combined (iliac and femoral) lesion had aorto-bifemoral bypass to get better proximal inflow. Just after the operation, we noticed his right lower extremity was pale and cold. Angiography revealed the thrombus distal to the occluded superficial femoral artery. Since the thrombus was too large to pass through any collateral vessels, it should be formed <i>in situ</i>. Femoro-popliteal bypass was added to the primary procedure with success.