Detection of ATP by "in line” 31P magnetic resonance spectroscopy during oxygenated hypothermic pulsatile perfusion of pigs' kidneys

Object: To demonstrate that adenosine triphosphate (ATP), which provides a valuable biomarker for kidney viability in the context of donation after cardiac death (DCD) transplantation, can be detected by means of 31P magnetic resonance spectroscopy (MRS) if kidneys are perfused with oxygenated hypothermic pulsatile perfusion (O2+HPP). Materials and methods: Porcine kidney perfusion was carried out using a home made, MR-compatible HPP-machine. Consequently, kidney perfusion could be performed continuously during magnetic resonance imaging and magnetic resonance spectroscopy recording. 31P MR spectroscopy consisted of 3-dimensional chemical shift imaging (CSI), which allowed for the detection of ATP level in line. 31P CSI was performed at 3tesla in 44min with a nominal voxel size of 6.1cc. Results: 31P CSI enabled the detection of renal ATP when pO2 was equal to 100kPa. With pO2 of 20kPa, only phosphomonoester, inorganic phosphate and nicotinamide adenine dinucleotide could be found. Semi-quantitative analysis showed that ATP level was 1.3mM in normal kidney perfused with pO2 of 100kPa. Conclusions: This combined technology may constitute a new advance in DCD organ diagnostics prior to transplantation, as it allows direct assessment of ATP concentration, which provides a reliable indicator for organ bioenergetics and viability. In this study, kidneys presenting no warm ischemia were tested in order to establish values in normal organs. The test could be easily integrated into the clinical environment and would not generate any additional delay into the transplantation clinical workflo

DCD Pigs' Kidneys Analyzed by MRI to Assess Ex Vivo Their Viability

Magnetic resonance imaging (MRI) gadolinium-perfusion was applied in simulated Donation after Cardiac Death (DCD) in porcine kidneys to measure intrarenal perfusion. Adenosine triphosphate (ATP) resynthesis during oxygenated hypothermic perfusion was compared to evaluate the "ex vivo organ viability". Adenine nucleotide (AN) was measured by P nuclear magnetic resonance (NMR) spectroscopy. Whereas this latter technique requires sophisticated hardware, gadolinium-perfusion can be realized using any standard proton-MRI scanner. The aim of this work was to establish a correlation between the two methods

Detection of ATP by "in line" 31P magnetic resonance spectroscopy during oxygenated hypothermic pulsatile perfusion of pigs' kidneys

To demonstrate that adenosine triphosphate (ATP), which provides a valuable biomarker for kidney viability in the context of donation after cardiac death (DCD) transplantation, can be detected by means of (31)P magnetic resonance spectroscopy (MRS) if kidneys are perfused with oxygenated hypothermic pulsatile perfusion (O(2)+HPP)

Intra-abdominal cooling system limits ischemia-reperfusion injury during robot-assisted renal transplantation

Robot-assisted kidney transplantation is feasible; however, concerns have been raised about possible increases in warm ischemia times. We describe a novel intra-abdominal cooling system to continuously cool the kidney during the procedure. Porcine kidneys were procured by standard open technique. Groups were as follow: Robotic renal transplantation with (n=11) and without (n=6) continuous intra-abdominal cooling and conventional open technique with intermittent 4°C saline cooling (n=6). Renal cortex temperature, magnetic resonance imaging and histology were analyzed. Robotic renal transplantation required a longer operative time, either with or without the cooling system, compared to the open approach (70.4±17.7 min and 74.0±21.5 min vs. 49.4±12.4 min, p-values<0.05). The temperature was lower in the robotic group with cooling system compared to the open approach group (6.5±3.1°C vs. 22.5±6.5°C; p=0.002) or compared to the robotic group without the cooling system (28.7±3.3°C; p=0.133). MRI parenchymal heterogeneities and histologic ischemia-reperfusion lesions were more severe in the robotic group without cooling than in the cooled (open and robotic) groups. Robot-assisted kidney transplantation prolongs the warm ischemia time of the donor kidney. We developed a novel intra-abdominal cooling system that suppresses the non-controlled rewarming of donor kidneys during the transplant procedure and prevents ischemia-reperfusion injuries. This article is protected by copyright. All rights reserved

Oxygenated hypothermic pulsatile perfusion versus cold static storage for kidneys from non heart-beating donors tested by in-line ATP resynthesis to establish a strategy of preservation

The scarcity of kidneys for transplantation impels an expansion of the donor source to include the use of organs from Maastricht II and Maastricht I non heart-beating donors. The aim of this study was to establish the best method to preserve kidneys from non heart-beating donors (NHBD): cold static storage (CSS) or perfusion. ATP production during kidney preservation has been retained as a measure of their energetic levels and, consequently, their viability. The presence of warm ischemia with both types of preservation was studied