Comparative analysis of in situ versus ex situ perfusion onflow and microcirculation in kidney procurement: Research on a porcine model

Abstract

Background: The first crucial step in transplantation appears to be the effective rinsingof the graft during organ procurement. Even though there is strong suspicionthat ex situ perfusion results in better rinsing of the graft,there is no proof for this hypothesis. The aim of this study was to analysethe differences of in situ and ex situ kidney perfusion ina porcine model.Methods: Standardised multiorgan procurement was performed in 15 German landrace pigs.Perfusion was carried out usinghistidine-tryptophan-ketoglutarate solution (HTK) under theapplication of pressure. In one kidney, in situ perfusion via theaorta was carried out while the second kidney received ex situperfusion via the renal artery (RA). Perfusate flow inside the aorta and theRA was recorded at different pressure steps. In order to visualise theeffect on the microcirculation, different coloured microparticles (MPs; 10μm) were administered via the aorta or RA. Subsequently, frozensections of the explanted kidneys were analysed histologically and MPs wereevaluated quantitatively.Results: Ex situ kidney perfusion resulted in significantly improved flowrates (P<0.0001) compared with in situ perfusion. Byapplying ex situ perfusion it was even possible to attainphysiological flow levels on the RA under the application of externalpressure of 150 to 200 mmHg. The amount of MPs was able to highlight thepositive impact of ex situ perfusion on microcirculation of thekidney graft (P<0.0001).Conclusions: The use of MPs represents a valuable tool for quantitative investigation andillustration of kidney perfusion in experimental setups. Additional exsitu perfusion is able to improve the quality of kidneyperfusion. © 2013 Foltys et al.; licensee BioMed Central Ltd.