Standardization of ischemic hepatic failure in pigs as a model for bioartificial liver assessment.

Abstract

A standard protocol of ischemic liver failure in pigs was examined to establish a system for assessing the efficacy of a bioartificial liver, based on clinical practice. The portal blood flow was extracorporeally bypassed into the cervical jugular vein, using a centrifugal blood pump. The portal vein and hepatic artery were then ligated. The maintenance protocol was established as follows: (1) the concentration of the inhaled anesthetic was decreased by 0.2% when the systolic blood pressure was <100 mmHg; (2) the volume of an infusion containing 5% glucose was increased to 10 ml/kg per hour when central venous pressure was <5 mmHg; (3) 20 ml of 50% glucose was injected intravenously when the blood glucose was <50 mg/dl; (4) 2000 units of heparin was injected intravenously when the activated clotting time was <150 s; (5) sodium bicarbonate was given when the blood pH was <7.3; (6) tidal volume was increased by 1 ml/kg when the pCO(2) was >80 mmHg; (7) oxygen was increased by 25% when the pO(2) was <100 mmHg. No vasopressors were used in the experiment. Our protocol reduced the operating time and minimized the risk of data deviation that can arise from variations in operating techniques and individual animal conditions. This experimental model is also easy to use as a bridge to transplantation.