The use of oncotic support agents in perfusion preservation

Abstract

Continuous perfusion of the kidney produces an increase in the extracellular space^1,2 usually accompanied by cell shrinkage leading to what has been termed the ‘exploded view’². This increase in extracellular space leads to tissue oedema which may have a detrimental effect on the distribution of intrarenal flow. The influence of fluid shifts in the tissue on perfusion parameters is evident during the later stages of perfusion as indicated by an increase in perfusion pressure and decreased flow³. At present all perfusates used in experimental and clinical renal preservation contain serum albumin for oncotic support. Unfortunately, serum albumin (MW 66000) escapes from the intravascular to the extravascular space during perfusion and thus with time intravascular oncotic pressure is diminished¹. In addition, perfusion-induced denaturation of albumin can occur and produce endothelial damage⁴. Theoretically, intracellular fluid distribution in the perfused kidney could be controlled by the addition of compounds to the perfusate which provide oncotic support and remain intravascular.