In organ transplantation, it is highly important to preserve the recovered organs in good condition. At present, a cold static storage of which aim is to suppress tissue metabolism is generally used. If the process from organ recovery to storage is not performed properly, the viability of the organ may be impaired and result in worse posttransplant outcomes. We herein propose the packing method of cooling and immersion storage from organ harvest to transportation to a transplant hospital. Considering current situation in Japan and overseas. we describe the standard protocol formulated by the Japanese Society for Transplantation.

Recently, it has become clear that machine perfusion preservation is a more beneficial than cold storage. Cold-induced preservation injury causes inadequate cellular metabolic function, the depletion of energy stores or the deleterious direct effects of cooling. Normothermic machine perfusion (NMP) can help maintain and recover graft function, and evaluate the viability. However, because it requires high level of oxygen, blood-based perfusates those may increase the risk of microvascular failure and bacterial growth, are used. Therefore, NMP remains a challenging problem. On the other hand, subnormothermic machine perfusion (SNMP) at around 20℃-25℃ needs lower level of oxygen compared to NMP. Herein, we demonstrate the current status and future of SNMP.

Current critical shortage of donor organs has led to increased use of extended-criteria donors (ECD) for transplantation. According to 2019 global statistics, 23% of all solid organ cadaveric transplants were performed using Donation after circulatory Death (DCD). The increasing use of ECDs has thus highlighted the limitations of the gold standard, static cold storage (SCS), and the research/development of machine perfusion (MP) preservation has become one of the "hottest topic" in organ preservation. This article aims to review the current progress of basic and clinical research on each MP method and their combinations, particularly focusing on the target temperatures such as Hypo-, Subnormo-, and Normothermic MP.

Extracorporeal organ perfusion has attracted attention for its potential to address several issues in organ preservation and transplantation. In this study, we aimed to identify a reliable method for evaluating kidneys undergoing extracorporeal perfusion, focusing specifically on the applicability of drug loading tests. Porcine kidneys obtained from a slaughterhouse were used to model organ damage following 3 hours of circulatory arrest. Kidneys were subjected to loading tests with circulatory agonists including adrenaline, verapamil, and nitroglycerin. In addition, renal function was assessed via loading tests with inulin, phenolsulfonaphthalein (PSP), and fluorescein isothiocyanate (FITC)-labeled albumin. In the circulatory experiments, vascular responses (i.e., changes in perfusion rate and vascular resistance) were observed in all cases despite severe ischemic damage. Among them, responses to adrenaline were observed even in highly injured kidneys that had undergone 18 hours of extracorporeal perfusion in addition to 3 hours of ischemia. Despite differences in the in vivo situation, the glomerular filtration rate (GFR) of inulin, rate of PSP excretion, and drug clearance could be measured quantitatively in the renal function experiments. These findings indicate that drug loading tests may be effective for both qualitative and quantitative assessment of vascular function and renal filtration capacity in extracorporeally perfused kidneys. Given that these assessments can aid in determining the degree of damage and residual function, they will likely be useful for evaluating extracorporeal perfused kidneys. in the future.

The issue of cold-stored donor kidneys falling into a secondary warm ischemic state during vascular anastomosis in the recipient body has been a longstanding problem since the beginning of organ transplantation therapy. The authors have successfully developed an organ protector that suppresses secondary warm ischemia in cold-stored kidneys by using insulating materials based on polymer chemistry and thermodynamics. In this review, we introduced the development process and the functions of the product, Organ Pocket, the world's first organ protector for kidney transplantation, which was successfully developed through the realization of medical-industrial collaboration.

The issue of cold-stored donor kidneys falling into a secondary warm ischemic state during vascular anastomosis in the recipient body has been a longstanding problem since the beginning of organ transplantation therapy. The authors have successfully developed an organ protector that suppresses secondary warm ischemia in cold-stored kidneys by using insulating materials based on polymer chemistry and thermodynamics. In this review, we introduced the development process and the functions of the product, Organ Pocket, the world's first organ protector for kidney transplantation, which was successfully developed through the realization of medical-industrial collaboration.