Using microdialysis for early detection of vascular thrombosis after kidney transplantation in an experimental porcine model

Background. In kidney transplantation (KTx), vascular thrombosis has a major impact on morbidity and graft survival. The ischaemia, caused by thrombosis, can lead to interstitial metabolite changes. The aim of this experimental study was to create conditions in which the graft would be prone to vascular thrombosis following KTx and then to evaluate the role of microdialysis (MD) for its early detection. Methods. Sixteen randomized pigs in the control group received heparin and immunosuppressive drugs, while the case group received none. Based on histopathological evidence of vascular thrombosis, the case group was subdivided into mildly and severely congested subgroups. Using MD, we evaluated the interstitial concentrations of glucose, lactate to pyruvate ratio, glutamate and glycerol in the transplanted grafts during different phases of KTx. Results. Following reperfusion, we noted considerable changes. The severely congested subgroup showed a low and decreasing level of glucose. Only in this group did the lactate to pyruvate ratio continue to increase until the end of monitoring. The glycerol level increased continuously in the entire case group and this increase was most significant in the severely congested subgroup. In all of the study groups, glutamate concentration remained in a low steady state until the end of monitoring. Conclusion. MD can be an appropriate method for early detection of vascular complications after KTx. Decreasing glucose levels, increased lactate to pyruvate ratio and increased glycerol levels are appropriate indicators for early detection of vascular thromboses following KTx. Particularly, the glycerol level could predict the necessity and urgency of intervention needed to ultimately save the transplanted kidney.