Ex vivo magnetic resonance imaging during normothermic machine perfusion - developing a novel non-invasive tool to assess donor kidney quality

R. Schutter, O.C. van Varsseveld, V.A. Lantinga, H.G.D. Leuvenink, R.J.H. Borra, C. Moers

Wednesday 13 march 2019

14:16 - 14:18h at Koningin Máximazaal

Categories: Basaal, Parallelsessie

Parallel session: Parallelsessie III - Basaal I

Background: Pre-transplant prognostic models and diagnostic tools that are currently available for deceased donor kidneys have insufficient independent predictive value to be used in decisions on organ acceptance or discard. As a result, such decisions always have an element of subjectivity. Normothermic machine perfusion (NMP) of renal grafts at 37°C provides an ideal platform for isolated organ imaging prior to transplantation. In recent years, novel magnetic resonance imaging (MRI) sequences have been developed, which can quantify important determinants of allograft quality, such as endothelial integrity, mitochondrial function and tissue stiffness. These parameters are likely to correlate with outcome after transplantation. The overall aim of this project is to provide evidence for the predictive value of ex vivo non-invasive MRI assessment of kidney grafts during normothermic machine perfusion. First, we performed a series of pilot experiments to test feasibility of this approach.

Methods: Five porcine slaughterhouse kidneys were used to optimize the setup and test several sequences for their relevance. NMP was performed with autologous red blood cells in Williams’ Medium E with the addition of creatinine, bovine serum albumin and amoxicillin with clavulanic acid. Segmental ischemia/reperfusion injury was induced by inflating and deflating a balloon catheter in one of the main branches of the renal artery. Imaging sequences were performed during different stages of the perfusion. Blood and urine samples were obtained, as well as histological samples at the end of the perfusion.

Results: A stable and reliable NMP setup for isolated kidneys inside a clinical MRI scanner was obtained. Pilot perfusions were mainly performed to develop and optimize the NMP setup. Experience was gained in developing a smooth logistical procedure and technical aspects of MRI sequences applicable to an ex vivo perfused kidney.

Conclusions: This pilot study showed that it is logistically and technically feasible to combine the promising (pre-transplant) evaluation of normothermic machine perfusion with ex vivo magnetic resonance imaging. Several important aspects of allograft quality could be imaged. After finalizing the optimization phase with porcine grafts, human discarded kidneys will be evaluated for allograft quality. Ultimately, we aim to image human donor kidneys that have been accepted for transplantation and correlate outcomes with ex vivo MRI data to develop an unique pre-transplant organ assessment tool.