RESUMEN
Fifteen consecutive patients with true or dissecting aneurysms of the thoracic descending aorta, and thoraco-abdominal aorta were operated upon under left thoracotomy with the support of partial cardiopulmonary bypass, equipment composed of a membrane oxygenator, centrifugal pump, and percutaneous thin wall cannulae which were all coated with covalently bonded heparin. The polyvinyl tube was coated with Biomate. The administration of systemic heparin was determined by an ACT of around 200 seconds. One perioperative death in a case treated by emergency operation for a ruptured descending aortic aneurysm occurred due to acute myocardial infarction. Other patients tolerated their operation well and are alive. No thromboembolic accident, bleeding tendency, nor organ failure were observed postoperatively in any other patients. In conclusion, the cardiopulmonary bypass using an antithrombotic circuit is safe and recommendable for thoracic descending or thoraco-abdominal aneurysm operations.