A TECHNIQUE FOR EXTRACORPOREAL-CIRCULATION IN THE GOETTINGEN MINIPIG ALLOWING RECOVERY AND LONG-TERM FOLLOW-UP

The objective of our study was to establish an animal model with extra corporeal circulation (ECC) for investigations on the long-term tolera bility of different pericardial substitutes using the Goettingen minip ig. A combination of halothane (0.4-0.6% vaporizer setting) in oxygen and nitrous oxide (FiO(2) 0.33), with the opioid piritramide (75 mu g/ kg/h i.v.) was used for anaesthesia. A muscle relaxant was not adminis tered. Due to the size of the animals (mean body weight 37.6 kg) the o perative procedure was the same as in humans. Specific changes preceed ing or following initiation of cardiopulmonary bypass (CPB), such as i nactivation of the coagulation system (400 IU heparin/kg i.v.), haemod ilution, and hypothermia (32 degrees C), did not result in any complic ation. We did not induce cardiac arrest during CPB in order to facilit ate haemodynamic stability after weaning from CPB. In three animals a temporary increase in blood pressure occurred after protamine (2.5-3.0 mg/kg i.v.) was given to reverse the heparinization. Within 60 minute s after the end of surgery all animals could be extubated when spontan eous breathing and cough reflex were present. The postoperative follow -up period of nine months was uneventful apart from one animal which d eveloped a superficial wound in the thoracic scar area. We conclude th at our technique for ECC is a safe method allowing recovery and long-t erm follow-up after cardiac surgery in a porcine animal model.