Orthotopic liver transplantation in pigs. An evaluation of different methods of avoiding the revascularization syndrome.

During hypothermia of a liver to be transplanted, a large quantity of K+ accumulates, which may cause myocardial dysfunction at revascularization. In our study we attempted to prevent this electrolytic imbalance. We used 58 Landrace pigs for 29 orthotopic liver transplants. The animals were divided into three groups. In group 1, vascular anastomoses were performed and the liver was revascularized with no specific attempt to prevent hyperkalemia. In group 2, the liver was perfused via the portal vein prior to revascularization in order to flush K+ and acid radicals. In group 3, extracorporeal circulation (ECC) between the previously anastomized inferior vena cava (IVC) below the liver and the jugular vein was employed. At revascularization, the blood was drained from the organ into the ECC which was equipped with a polyacrylonitrile dialyzer (PAN). The recipients in group 1 were subject to cardiac arrest caused by hyperkalemia and acidosis at revascularization. The recipients in group 2 showed myocardial dysfunction during revascularization; in 20% of the cases, cardiac arrest ensued. In group 3 the blood that flowed into the PAN before reentering systemic circulation showed normal levels of K+ and a normal acid base balance. The animals in this group did not demonstrate any changes in cardiac rhythm (group 1:K+ = 12.95 +/- 2.77; group 2:K+ = 7.17 +/- 2.34; [1-2 P less than 0.01]; group 3:K+ = 2.96 +/- 0.76; [1-3 P less than 0.001]).