Liver function in the pig: 1. The effects of 30 minutes' normothermic ischaemia

Abstract

A preparation was developed in the pig in which transhepatic samples could be taken, and the duration for which the pig liver would tolerate ischaemia was studied. Total occlusion of the hepatic artery, portal vein and inferior Venn cava was caused after studies o j the effects of occlusion of the portal vein or the vena cava alone. Adequate splanchnic decompression was provided by a splenojugular bypass.Reversible changes were noted in the acidlbase status and potassium levels ajter ischaemia. Aspartate transaminase (SGOT) levels rose and remained elevated during the hour of study following occlusion. Alkaline phosphatase and glucose levels changed but remained within normal laboratory limits, although there appeared to be a release of glucose from the hepatic veins after occlusion. Portal pressure increased reversibly after ischaemia and returned to normal within I hour. Bile pow ceased during inflow occlusion and resumed I S minutes after the release of the clamps.Survival rates in animals which had undergone ischaemin were the same as those in control animals. The conclusion is drawn that the pig will tolerate hepatic inflow occlusion for 30 minutes with reversible changes and no decrease in survival.

For How Long Can the Liver Tolerate Ischaemia?

“…Our group has previously shown that pigs die from progressive hypotension and acidosis within 35 min of portal vein occlusion without splanchnic decompression [6], External porto systemic shunts often fail to function for pro longed periods and this may explain the inabil ity to extend the ischaemic time beyond 3 h in previous studies. Using a side-to-side porta caval shunt von Sonvnoggyex al.…”

“…Recent reports would indicate that the liv er, both in man and animals, can tolerate lon ger periods of normothermic ischaemia than is generally accepted [4][5][6][7][8][9], It has often been stated that 20 min is the 'safe period' for liver blood flow occlusion in man. However, suc cessful occlusion of the portal triad for longer periods has been reported, and it has been proposed that the safe period for hepatic ischaemia in man could be extended to 1 h [4], Dogs and non-human primates tolerate hepatic ischaemia poorly [2.…”

Technique of Porcine Liver Procurement and Orthotopic Transplantation using an Active Porto-Caval Shunt

“…The total occlusion of the vena cava during the cava reconstruction phase impairs the hemodynamic stability of the pig. Although a few reports show that porcine OLTx can be accomplished during total cava and portal vein occlusion of less than 25 min 16,17 , a porto-cava-jugular bypass technique for the time of vascular reconstruction is the safer and more practical option [7][8][9]18 . In the authors' experience, a passive porto-jugular bypass is not optimal to keep the pig hemodynamically stable during the anhepatic phase.…”

Experimental Liver Transplantation

“…Hypotension occurs after more than 30 minutes and leads to immediate or late irreversible shock. (Battersby et al, 1974) Temporary clamping of the supracoeliac aorta is performed by some authors to stabilize the hemodynamic conditions during the anhepatic phase without venous bypass. If the anhepatic phase without veno-venous bypass lasts less than 30 min, temporary aortic occlusion may not be mandatory.…”