One month survival with the undulation pump total artificial heart in a goat

The undulation pump is a small continuous flow displacement-type blood pump. The undulation pump to-tal artificial heart (UPTAH) is a unique implantable total artificial heart using undulation pumps. An adult female goat weighing 45.8 kg was used for implantation. The natural heart was replaced with the UPTAH under extracorporal circulation. The cardiac output (CO) was maintained to 100 ml/kg/min by controlling the right pump manually. To prevent lung edema, the left pump was controlled automatically to maintain the left atrial pressure below 20 mm Hg. The CO was maintained for 2 weeks. Thereafter, the CO gradually decreased. The goat suddenly died because of a brain stroke on the 31st postoperative day. At autopsy, the cavity of the left atrial cuff was almost occupied by the big pannus-like thrombus, which was thought to be the cause of death. Improvement of the atrial cuff is necessary to obtain longer survival and is being modified. No thrombus was found inside the pumps. However, temperature rise in a left motor was a problem. Improvement of the efficiency in a motor is necessary. Although many problems still remained, 1 month survival could be obtained with this unique implantable TAH using continuous flow displacement-type blood pumps.