Normothermic machine perfusion system. The perfusion circuit consisted of a perfusion chamber, two Masterflex peristaltic pumps (Waterbath pump and outflow pump) (Cole Parmer, Vernon Hill, IL), a membrane oxygenator (Radnoti), a heat exchanger (Radnoti), and a bubble trap (Radnoti). Liver temperature was regulated by a water bath (Lauda, Brinkmann, Westbury, NY), intrahepatic pressure was monitored with a pressure sensor, and samples were collected without disturbing the liver via sampling ports.