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Transplantation
Published in Karl H. Pang, Nadir I. Osman, James W.F. Catto, Christopher R. Chapple, Basic Urological Sciences, 2021
Jonathon Olsburgh, Rhana H. Zakri
Strategies to minimise ischaemic cell death:Cooling to slow the metabolic rate.Perfusing organs with cold preservation solution (reduces electrolyte imbalance, provides buffers against acidosis, and reduces osmotic swelling).Machine perfusion.
Development and Optimization of Preservation Solutions
Published in John J. Lemasters, Constance Oliver, Cell Biology of Trauma, 2020
For clinical organ preservation there are two methods. Simple cold storage, the most popular, involves flushing the blood out of the organ and infusing it with the cold (about 4°C) preservation solution. The second method, machine perfusion, involves continuous perfusion of the organ with a perfusate at 4 to 8°C. Perfusion is done at a low pressure (about 40 to 55 mmHg systolic) and usually with a pulsatile flow at a rate of about 0.6 to 1.0 ml/min/g of tissue. Perfusion is used clinically only for the kidney. An advantage of perfusion is that end products of metabolism can be removed and that oxygen and other substrates can be delivered to the organ. Thus, energy-requiring reactions that continue even at hypothermia can be supplied with a constant source of ATP derived from mitochondrial oxidative phosphorylation. Perfusion, therefore, provides longer preservation of organs than cold storage, and in general it preserves the quality of organs better for short periods of time. However, the ease of cold storage and the fact that only about 24 h of preservation is required to meet most needs has made it the method of choice.
Urological and Biochemical Aspects of Transplantation Biology
Published in Anthony R. Mundy, John M. Fitzpatrick, David E. Neal, Nicholas J. R. George, The Scientific Basis of Urology, 2010
In the early days of renal transplantation, there was considerable uncertainty as to how to store the organ. The two methods were simple static cold storage and dynamic machine perfusion, which was also performed at cold temperature. Most groups stopped machine preservation when it was discovered that, generally, the longer the kidney remained in storage, the worse was the outcome (7). Certain groups, principally Belzer et al. from the United States, persisted with machine perfusion, and when the solutions were improved, it was found that the kidney preservation was better with this method than with static storage (8). This was principally the case with marginal donor kidneys, and this method had the added benefit of allowing the surgeons to improve their viability assessment by assessing the resistance and flow through the kidney (3, 9).
Devices for donor lung preservation
Published in Expert Review of Medical Devices, 2022
Cora R Bisbee, Curry Sherard, Jennie H. Kwon, Zubair A. Hashmi, Barry C. Gibney, Taufiek Konrad Rajab
Ex vivo lung perfusion (EVLP) is a novel lung preservation strategy with potential advantages over SCS. Most notably, EVLP supports greater use of organs from extended-criteria donors (ECD) and extension of lung preservation time with comparable clinical outcomes [22,23]. Machine perfusion is a method involving organ perfusion with a controlled flow of perfusate through a leukocyte filter and oxygenator which are subsequently connected to a heater/cooler unit and gas exchange membrane, as shown in Figure 1. The perfusate then enters the lung through a cannula in the pulmonary artery and venous return is collected through the left atrium and recirculated. A ventilator is connected to the trachea to allow for a protected airway after the lungs have been warmed to physiological temperatures (normothermia) [10]. Each organizations protocols can vary based on perfusate, flow rate, ventilation settings, and pressure.
Comparison of Centrifugal and Pulsatile Perfusion to Preserve Donor Kidneys Using Ex Vivo Subnormothermic Perfusion
Published in Journal of Investigative Surgery, 2022
Patrick P. W. Luke, Larry Jiang, Aushanth Ruthirakanthan, Daniel Lee, Qizhi Sun, Mahms Richard-Mohamed, Justin Kwong, Shahid Aquil, Rafid Alogaili, Aaron Haig, Alp Sener, Rabindra N. Bhattacharjee
In the kidney literature, Gallinat et al. found that pulsatile perfusion resulted in higher perfusate flow rates, greater clearance of creatinine and urea, and less tubular cell injury following reperfusion [18]. However, this study was performed utilizing a hypothermic non-oxygenated machine perfusion strategy. In our study, we preserved kidneys at 22° C, which we had previously determined to be the optimal temperature for oxygenated perfusion [6,7]. We found that there was no sign that pulsatile perfusion affected renal function, or injury any better than centrifugal perfusion. Unlike the previous findings that pulsatile perfusion may promote an anti-inflammatory phenotype [19], we found that urinary IL-6 were similar between pulsatile and centrifugal perfusion groups. It is possible that the advantage gained by pulsatile perfusion in a metabolically inactive system at 4 °C may be lost when organs are preserved in an oxygenated, metabolically active setting.
Cost-utility analysis of normothermic liver perfusion with the OrganOx metra compared to static cold storage in the United Kingdom
Published in Journal of Medical Economics, 2020
Mehdi Javanbakht, Atefeh Mashayekhi, Miranda Trevor, Michael Branagan-Harris, Jowan Atkinson
The majority of clinical inputs were retrieved from a RCT which aimed to test the efficacy of machine perfusion against conventional cold storage in liver transplantation. From the initial 334 randomized livers, 170 were allocated to the NMP arm and 164 to the SCS arm. After application of the exclusion criteria, 137 and 133 livers were left at each arm, respectively. After organ retrieval and following the preservation period, 120 livers in the NMP arm and 100 livers in the SCS arm were available for transplantation; this gives a difference in the discard rate between arms of 12.4%5. Furthermore, post-reperfusion syndrome (PRS) rates and EAD rates were higher in the SCS arm compared to the NMP arm. LoS in hospital/ICU and 1-year survival rates were not statistically different between the two groups5. The data for the model was supplemented with data from other sources and the Cochrane pyramid of evidence was considered where possible. Further information about the sources for the various model inputs are detailed in the following sections.