The possibility of machine perfusion of the heart was shown by Hassanein in 1998. The Organ Care System (OCS, TransMedics, Andover, MA) was developed based on his prototype. This system perfuses the heart according to the Langendorff perfusion principle. The PROCEED II trial showed the safety and efficacy of this system in preserving for a longer period than cold storage the hearts which were recovered from standard criteria donors. Several small studies also showed the safety and efficacy of this system in preserving the hearts recovered from extended criteria donors. Heart transplantation using hearts recovered from donors of circulatory-determined death (DCD donation) has been gradually accepted in selected centers. OCS is an indispensable device to perfuse, evaluate and transport the heart. Comparable transplant results from using an OCS system were published for DCD donation and regular brain-dead donation (DBD) from several centers. Recently, the Donors After Circulatory Death Heart Trial was conducted in the United States, and showed that DCD-donated heart transplantation was as safe and effective as DBD transplantation and the perfusion by the OCS system was useful.

The insufficient number of grafts is a major problem in kidney transplantation, and graft preservation with ex vivo machine perfusion is attracting attention to facilitate kidney donation from so-called marginal donors, such as those with acute kidney injury and/or an older age. Since 1985, several clinical trials have been conducted comparing kidney graft preservation between cold machine perfusion and simple cold preservation in several renal transplant centers. However, the results have not contributed to the widespread clinical used of machine perfusion, as most of the studies were relatively small in scale and did not yield definitive results that preservation with cold machine perfusion was superior. In 2009, an international randomized controlled trial by Moers et al. reported that kidney graft preservation with cold machine perfusion reduced the risk of a delayed graft function, decreased serum creatinine levels, and significantly improved the one-year graft survival compared to simple cold storage. Since then, kidney graft preservation with cold machine perfusion using the LifePort Kidney Transporter machine has been clinically applied worldwide. In addition, clinical trials of normothermic machine perfusion as a next-generation preservation method are underway to promote the clinical application of renal transplantation. Following the first clinical application in 2011 and a clinical study in 2013 using normothermic machine perfusion in the United Kingdom, the results of a clinical trial of graft preservation with normothermic machine perfusion in renal transplantation in North America and India were reported in 2022. Graft preservation with ex vivo machine perfusion is expected to help solve the global shortage of kidney grafts.

The use of grafts from marginal donors including donation after cardiac death (DCD) would greatly contribute to the expansion of the donor organ pool. However, unlike the recipients with marginal graft experience a higher incidence of primary non-function (PNF), delayed graft function (DGF). Ultimately, DGF results in poor long-term graft survival.

The current organ shortage has stimulated interest for machine perfusion in the use of marginal liver grafts. This paper highlights the different preservation temperature and oxygenation for marginal liver grafts as a novel source of transplantation and provides a through overview from their history to a future direction.

Brain-dead donor lungs are frequently subjected to injuries acquired during brain death and intensive care unit (ICU) -related complications, which would increase the risk of primary graft dysfunction after lung transplantation. Ex vivo lung perfusion (EVLP), in which donor lungs are ventilated and perfused under normothermic conditions outside the body, enables clinicians to accurately evaluate the donor lung function prior to transplantation. Hence, the EVLP procedure was successfully introduced into clinical practice, expanded the donor lung pool, and showed favorable post-transplant outcomes in a growing number of transplant centers worldwide. The EVLP system and techniques have recently been employed for the assessment of extended criteria donor lungs that were otherwise initially unacceptable in clinical lung transplantation in Japan. The advancement of EVLP from organ assessment to organ treatment or repair will be the next challenging stage toward realizing what we have termed a personalized medicine approach to management of the donor organ.

【Objective】 The severe organ donor shortage is a crucial issue for heart transplantation (HTx) in Japan. We have aggressively accepted marginal donor hearts declined by other institutions since 2016, when the waiting time for HTx increased gradually.

【Design】 This is a single center, retrospective observational study.

【Methods】 All HTx recipients at National Cerebral and Cardiovascular Center from 1999 to 2021 were reviewed and divided into two groups: those who underwent HTx from 1999 to 2015 (early HTx group), and those who underwent HTx from 2016 to 2021 (late HTx group). The participants’ characteristics including risk factors of donor hearts were compared between the two groups.

【Results】 Recipients in the late HTx group were older compared to the early HTx group; the late HTx group demonstrated a significantly longer waiting time for HTx. On comparison of donor characteristics, older age, shorter ischemic time, and lower-dose inotropic use were observed in the late HTx group compared to the early HTx group. However, the five-year overall survival was comparable between the two groups.

【Conclusion】 Older donor hearts were more aggressively used for HTx beginning in 2016. The disadvantages of these organs may be compensated by shorter ischemic time and lower-dose inotropic use, which resulted in a comparable five-year survival. Careful assessment of donors’ risk factors and recipient-donor matching might aid in further expanding the potential donor pool in Japan.

【Background】 Few studies have assessed donor-specific antibodies (DSA) and anti-human leucocyte antigen (HLA) antibodies associated with the transplantation (Tx) of organs other than kidney.

【Methods】 A total of 31 institutions participated in the current study. Patients who satisfied the study criteria were enrolled prospectively, and rituximab was used according to each institution’s clinical protocol for desensitization before Tx when patients had preexisting DSA or anti-HLA antibodies (desensitization cohort) or to treat post-Tx antibody-mediated rejection (ABMR) (ABMR treatment cohort). The desensitization cohort comprised four liver transplants, four kidney-pancreas transplants, and one heart transplant, and the ABMR treatment cohort contained two liver transplants, two heart transplants, and one lung transplant. In the desensitization cohort, organs ultimately were not allocated for the patient awaiting a heart transplant and one patient awaiting a kidney-pancreas transplant.

【Results】 In the desensitization cohort, DSA or anti-HLA antibodies decreased in the four liver Tx patients and three of the kidney-pancreas Tx patients. Although T-cell mediated rejection occurred in two patients, they did not develop ABMR. One pancreatic graft was lost due to post-transplantation thrombosis; all other grafts and all patients survived. In the ABMR treatment cohort, DSA decreased after ABMR treatment in one heart Tx patient and two liver Tx patients. Acute ABMR was eliminated completely only in the patient who developed the complication early after liver Tx.

【Conclusion】 Rituximab was well-tolerated, both during desensitization and as part of ABMR treatment for Tx of organs other than kidney.