Normothermic regional perfusion for donation after circulatory death without prior heparinization. Transplantation. 2014;97:1272-1278. [PMID: 24646774 DOI: 10.1097/tp.0000000000000082]

Normothermic Machine Perfusion and Normothermic Regional Perfusion of DCD Kidneys Before Transplantation: A Systematic Review

BACKGROUND

To overcome organ shortages, donation after circulatory death (DCD) kidneys are being increasingly used for transplantation. Prior research suggests that DCD kidneys have inferior outcomes compared with kidneys donated after brain death. Normothermic machine perfusion (NMP) and normothermic regional perfusion (NRP) may enhance the preservation of DCD kidneys and improve transplant outcomes. This study aimed to review the evidence surrounding NMP and NRP in DCD kidney transplantation.

METHODS

Two independent reviewers conducted searches for all publications reporting outcomes for NMP and NRP-controlled DCD kidneys, focusing on delayed graft function, primary nonfunction, graft function, graft survival, and graft utilization. Weighted means were calculated for all relevant outcomes and controls. Formal meta-analyses could not be conducted because of significant heterogeneity.

RESULTS

Twenty studies were included for review (6 NMP studies and 14 NRP studies). Delayed graft function rates seemed to be lower for NRP kidneys (24.6%) compared with NMP kidneys (54.3%). Both modalities yielded similar outcomes with respect to primary nonfunction (NMP 3.3% and NRP 5.6%), graft function (12-mo creatinine 149.3 μmol/L for NMP and 129.9 μmol/L for NRP), and graft utilization (NMP 83.3% and NRP 89%). Although no direct comparisons exist, our evidence suggests that both modalities have good short- and medium-term graft outcomes and high graft survival rates.

CONCLUSIONS

Current literature demonstrates that both NMP and NRP are feasible strategies that may increase donor organ utilization while maintaining acceptable transplant outcomes and likely improved outcomes compared with cold-stored DCD kidneys. Further research is needed to directly compare NRP and NMP outcomes.

British Transplantation Society guidelines on abdominal organ transplantation from deceased donors after circulatory death

The British Transplantation Society (BTS) 'Guideline on transplantation from deceased donors after circulatory death' has recently been updated and this manuscript summarises the relevant recommendations in abdominal organ transplantation from Donation after Circulatory Death (DCD) donors, encompassing the chapters on liver, kidney, pancreas and islet cell transplantation.

Bronchial Stenosis After Lung Transplantation From cDCD Donors Using Simultaneous Abdominal Normothermic Regional Perfusion: A Single-center Experience

BACKGROUND

Controlled donation after circulatory death (cDCD) has increased the number of lung donors significantly. The use of abdominal normothermic regional perfusion (A-NRP) during organ procurement is a common practice in some centers due to its benefits on abdominal grafts. This study aimed to assess whether the use of A-NRP in cDCD increases the frequency of bronchial stenosis in lung transplant (LT) recipients.

METHODS

A single-center, retrospective study including all LTs was performed between January 1, 2015, and August 30, 2022. Airway stenosis was defined as a stricture that leads to clinical/functional worsening requiring the use of invasive monitoring and therapeutic procedures.

RESULTS

A total of 308 LT recipients were included in the study. Seventy-six LT recipients (24.7%) received lungs from cDCD donors using A-NRP during organ procurement. Forty-seven LT recipients (15.3%) developed airway stenosis, with no differences between lung recipients with grafts from cDCD (17.2%) and donation after brain death donors (13.3%; P  = 0.278). A total of 48.9% of recipients showed signs of acute airway ischemia on control bronchoscopy at 2 to 3 wk posttransplant. Acute ischemia was an independent risk factor for airway stenosis development (odds ratio = 2.523 [1.311-4.855], P  = 0.006). The median number of bronchoscopies per patient was 5 (2-9), and 25% of patients needed >8 dilatations. Twenty-three patients underwent endobronchial stenting (50.0%) and each patient needed a median of 1 (1-2) stent.

CONCLUSIONS

Incidence of airway stenosis is not increased in LT recipients with grafts obtained from cDCD donors using A-NRP.

Outcomes of livers from donation after circulatory death donors with extended agonal phase and the adjunct of normothermic regional perfusion

The liver performs important functions that are essential for life. If the liver fails, patients will die unless they receive a new liver from a donor (transplant). Unfortunately, there are not enough livers for everyone and some patients die while waiting for a suitable organ. This article describes a novel technique that allows resuscitation and testing of a potential donor liver so that more patients can safely receive a transplant.

Liver Transplantation Outcomes From Controlled Circulatory Death Donors: Static cold storage vs in situ normothermic regional perfusion vs ex situ normothermic machine perfusion

OBJECTIVE

To compare the outcomes of livers donated after circulatory death (DCD) and undergoing either in situ normothermic regional perfusion (NRP) or ex situ normothermic machine perfusion (NMP) with livers undergoing static cold storage (SCS).

SUMMARY OF BACKGROUND DATA

DCD livers are associated with increased risk of primary nonfunction, poor function, and nonanastomotic strictures (NAS), leading to underutilization.

METHODS

A single center, retrospective analysis of prospectively collected data on 233 DCD liver transplants performed using SCS, NRP, or NMP between January 2013 and October 2020.

RESULTS

Ninety-seven SCS, 69 NRP, and 67 NMP DCD liver transplants were performed, with 6-month and 3-year transplant survival (graft survival noncensored for death) rates of 87%, 94%, 90%, and 76%, 90%, and 76%, respectively. NRP livers had a lower 6-month risk-adjusted Cox proportional hazard for transplant failure compared to SCS (hazard ratio 0.30, 95%CI 0.08-1.05, P = 0.06). NRP and NMP livers had a risk-adjusted estimated reduction in the mean model for early allograft function score of 1.52 (P < 0.0001) and 1.19 (P < 0.001) respectively compared to SCS. Acute kidney injury was more common with SCS (55% vs 39% NRP vs 40% NMP; P = 0.08), with a lower risk-adjusted peak-to-baseline creatinine ratio in the NRP (P = 0.02). No NRP liver had clinically significant NAS in contrast to SCS (14%) and NMP (11%, P = 0.009), with lower risk-adjusted odds of overall NAS development compared to SCS (odds ratio = 0.2, 95%CI 0.06-0.72, P = 0.01).

CONCLUSION

NRP and NMP were associated with better early liver function compared to SCS, whereas NRP was associated with superior preservation of the biliary system.

Kidney Transplants From Donors on Extracorporeal Membrane Oxygenation Prior to Death Are Associated With Better Long-Term Renal Function Compared to Donors After Circulatory Death

Donation after circulatory death (DCD) allows expansion of the donor pool. We report on 11 years of Italian experience by comparing the outcome of grafts from DCD and extracorporeal membrane oxygenation (ECMO) prior to death donation (EPD), a new donor category. We studied 58 kidney recipients from DCD or EPD and collected donor/recipient clinical characteristics. Primary non function (PNF) and delayed graft function (DGF) rates, dialysis need, hospitalization duration, and patient and graft survival rates were compared. The estimated glomerular filtration rate (eGFR) was measured throughout the follow-up. Better clinical outcomes were achieved with EPD than with DCD despite similar graft and patient survival rates The total warm ischemia time (WIT) was longer in the DCD group than in the EPD group. Pure WIT was the highest in the class II group. The DGF rate was higher in the DCD group than in the EPD group. PNF rate was similar in the groups. Dialysis need was the greatest and hospitalization the longest in the class II DCD group. eGFR was lower in the class II DCD group than in the EPD group. Our results indicate good clinical outcomes of kidney transplants from DCD despite the long “no-touch period” and show that ECMO in the procurement phase improves graft outcome, suggesting EPD as a source for pool expansion.

Advances in Kidney Preservation Techniques and Their Application in Clinical Practice

The use of cold preservation solutions to rapidly flush and cool the kidney followed by static cold storage in ice has been the standard kidney preservation technique for the last 50 y. Nonetheless, changing donor demographics that include organs from extended criteria donors and donation after circulatory death donors have led to the adoption of more diverse techniques of preservation. Comparison of hypothermic machine perfusion and static cold storage techniques for deceased donor kidneys has long been debated and is still contested by some. The recent modification of hypothermic machine perfusion techniques with the addition of oxygen or perfusion at subnormothermic or near-normothermic temperatures are promising strategies that are emerging in clinical practice. In addition, the use of normothermic regional perfusion to resuscitate abdominal organs of donation after circulatory death donors in situ before cold flushing is also increasingly being utilized. This review provides a synopsis of the different types of preservation techniques including their mechanistic effects and the outcome of their application in clinical practice for different types of donor kidney.

A systematic review and meta-analyses of regional perfusion in donation after circulatory death solid organ transplantation

In donation after circulatory death (DCD), (thoraco)abdominal regional perfusion (RP) restores circulation to a region of the body following death declaration. We systematically reviewed outcomes of solid organ transplantation after RP by searching PubMed, Embase, and Cochrane libraries. Eighty-eight articles reporting on outcomes of liver, kidney, pancreas, heart, and lung transplants or donor/organ utilization were identified. Meta-analyses were conducted when possible. Methodological quality was assessed using National Institutes of Health (NIH)-scoring tools. Case reports (13/88), case series (44/88), retrospective cohort studies (35/88), retrospective matched cohort studies (5/88), and case-control studies (2/88) were identified, with overall fair quality. As blood viscosity and rheology change below 20 °C, studies were grouped as hypothermic (HRP, ≤20 °C) or normothermic (NRP, >20 °C) regional perfusion. Data demonstrate that RP is a safe alternative to in situ cold preservation (ISP) in uncontrolled and controlled DCDs. The scarce HRP data are from before 2005. NRP appears to reduce post-transplant complications, especially biliary complications in controlled DCD livers, compared with ISP. Comparisons for kidney and pancreas with ISP are needed but there is no evidence that NRP is detrimental. Additional data on NRP in thoracic organs are needed. Whether RP increases donor or organ utilization needs further research.

Kidney Transplants in Controlled Donation Following Circulatory Death, or Maastricht Type III Donors, With Abdominal Normothermic Regional Perfusion, Optimizing Functional Outcomes

Supplemental Digital Content is available in the text.

Background.

Warm ischemia time and ischemia-reperfusion damage result in higher rates of delayed graft function and primary nonfunction in kidney transplants (KTs) from controlled donation after circulatory death (cDCD). This study aimed to assess early and late kidney function and patient and graft survival of KT from cDCD preserved with normothermic regional perfusion (NRP) and to compare with KT from brain death donors (DBDs) and cDCD preserved with rapid recovery (RR).

Methods.

Patients who received a KT at our institution from 2012 to 2018 were included, with a minimum follow-up period of 1 y. They were categorized by donor type and conditioning methods: DBD, cDCD with NRP, and cDCD with RR. Early and late graft function, along with patient and graft survival were analyzed in all groups.

Results.

A total of 182 KT recipients were included in the study (98 DBD and 84 cDCD). Out of the cDCDs, 24 kidneys were recovered with the use of NRP and 62 with RR; 22 of the 24 kidneys were ultimately transplanted. The cDCD using NRP group showed lower rates of delayed graft function compared with the cDCD with RR group (36.3% versus 46.7%, P = 0.01). Also, primary nonfunction rates were lower in the cDCD using NRP group (4.5% versus 6.4% cDCD-RR and 10.2% DBD). Patient survival rates were >90% in all groups. No differences were found in graft survival rates at 1 y.

Conclusions.

The use of abdominal NRP improves early function recovery of KT from cDCD, making their outcomes comparable with those of DBD.

Extra-Corporeal Membrane Oxygenation Cadaver Donors: What about Tissues Used as Allografts?

Several studies demonstrated the efficacy of post-mortem extracorporeal membrane oxygenation (ECMO) on donors in preserving organ function addressing organ transplantation. Nevertheless, no common and shared evidence was reached about the possibility of using ECMO donors in tissue harvesting. Therefore, this work aimed first to review the current scientific literature about ECMO donors, and then to focus on the use of ECMO tissues as allografts, mainly addressing musculoskeletal tissues, which are of the most interest for reconstruction. A search was conducted on the current scientific literature, focusing on the keywords "ECMO" and "Donor". Several online databases were used, including PubMed, Scopus, and Web of Science. From the preliminary search, 478 articles were obtained, out of which 173 specifically reported the use of ECMO for donation and transplantation purposes. Literature reported extensive analyses of ECMO organs-overall from the abdomen-both in pre- and post-transplantation studies. On the other hand, ECMO tissues were explanted only in a very limited number of cases; moreover, no information was referred about their status and use. A revision of the current scientific literature highlighted the lack of information concerning ECMO tissues and the necessity to perform preclinical, ex vivo studies to compare allografts from ECMO donors, with respect to standard donors, and, thus, to verify whether they can be harvested and implanted safely and with efficacy.

Consensus statement on normothermic regional perfusion in donation after circulatory death: report from the European Society for Organ Transplantation's Transplant Learning Journey

Normothermic regional perfusion (NRP) in donation after circulatory death (DCD) is a safe alternative to in situ cooling and rapid procurement. An increasing number of countries and centres are performing NRP, a technically and logistically challenging procedure. This consensus document provides evidence-based recommendations on the use of NRP in uncontrolled and controlled DCDs. It also offers minimal ethical, logistical and technical requirements that form the foundation of a safe and effective NRP programme. The present article is based on evidence and opinions formulated by a panel of European experts of Workstream 04 of the Transplantation Learning Journey project, which is part of the European Society for Organ Transplantation.

Complications during multiorgan retrieval and pancreas preservation

In pancreas transplantation, complications can arise at each step of the process, from the initial selection of donors and recipients through the surgical technique itself and the post-operative period, when lifelong immunosuppression is required. In the early steps, careful retrieval and preservation of the pancreas are crucial for the viability of the organ and ultimate success of the transplant. The pancreas is a low-flow gland, making it highly sensitive to transplantation conditions and presenting risk of pancreatitis due to periods of ischemia. The two groups of donors - after brain death (DBD) or after cardiac arrest (DCD) - require different strategies of retrieval and preservation to avoid or reduce the risk of complications developing during and after the transplantation. For DBD donor transplantation, multiorgan retrieval and cold preservation is the conventional technique. Asystole donor (DCD) transplantation, in contrast, can benefit from the newest technologies, such as hypothermic and especially normothermic preservation machines (referred to as NECMO), to optimize organ preservation. The latter has led to an increase in the pool of donors by facilitating recuperation of organs for transplantation that would have been discarded otherwise.

Machine Perfusions in Liver Transplantation: The Evidence-Based Position Paper of the Italian Society of Organ and Tissue Transplantation

The use of machine perfusion (MP) in liver transplantation (LT) is spreading worldwide. However, its efficacy has not been demonstrated, and its proper clinical use has far to go to be widely implemented. The Società Italiana Trapianti d'Organo (SITO) promoted the development of an evidence-based position paper. A 3-step approach has been adopted to develop this position paper. First, SITO appointed a chair and a cochair who then assembled a working group with specific experience of MP in LT. The Guideline Development Group framed the clinical questions into a patient, intervention, control, and outcome (PICO) format, extracted and analyzed the available literature, ranked the quality of the evidence, and prepared and graded the recommendations. Recommendations were then discussed by all the members of the SITO and were voted on via the Delphi method by an institutional review board. Finally, they were evaluated and scored by a panel of external reviewers. All available literature was analyzed, and its quality was ranked. A total of 18 recommendations regarding the use and the efficacy of ex situ hypothermic and normothermic machine perfusion and sequential normothermic regional perfusion and ex situ MP were prepared and graded according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) method. A critical and scientific approach is required for the safe implementation of this new technology.

Transplant Outcomes of Donation After Circulatory Death Livers Recovered With Versus Without Premortem Heparin Administration

Premortem heparin administration during donation after circulatory death (DCD) organ recovery is thought to optimize liver perfusion. However, premortem heparinization is not universally practiced in the United States and limited data exist regarding its utility. US registry data were accessed between January 1, 2003, and March 10, 2017, and 2 cohorts were ascertained: (1) DCD donor livers recovered for transplantation (n = 5495) and (2) liver-only adult transplant recipients of DCD livers (n = 3754). Exclusions were donor unknown heparin status (n = 40), positive donor hepatitis B surface antigen (n = 4) and hepatitis C virus (n = 120) serologies, and for the outcomes analysis, livers placed outside the United States (n = 10). Discard rates and graft outcomes were examined from cohorts 1 and 2, respectively. Of 5495 DCD livers recovered for transplant, 589 (10.7%) donors did not receive premortem heparin (no heparin) and the remaining 4906 (89.3%) received heparin (heparin). Liver discard was similar between the no heparin (30.6%) and heparin groups (30.8%; P = 0.90). Heparin status was not associated with liver discard on multivariate analysis (adjusted odds ratio, 0.97; 95% confidence interval [CI], 0.80-1.18 P = 0.76). The cumulative probability of overall graft survival was lower in the no heparin group relative to the heparin group (P < 0.05), and this finding persisted on multivariate analysis. No heparin group transplants had an 18% higher hazard of overall graft failure compared with those that received heparin (adjusted hazard ratio, 1.18; 95% CI, 1.01-1.38; P < 0.05). In conclusion, organ recovery heparin administration status was not associated with liver discard. Failure to pretreat organ donors with premortem heparin correlates with worse liver transplant graft survival compared with heparin-treated livers.

Machine perfusion in abdominal organ transplantation: Current use in the Netherlands

Scarcity of donor organs and the increment in patients awaiting a transplant increased the use of organs from expanded criteria donors or donation after circulatory death. Due to the suboptimal outcomes of these donor organs, there is an increased interest in better preservation methods, such as ex vivo machine perfusion or abdominal regional perfusion to improve outcomes. This state-of-the-art review aims to discuss the available types of perfusion techniques, its potential benefits and the available evidence in kidney, liver and pancreas transplantation. Additionally, translational steps from animal models towards clinical studies will be described, as well as its application to clinical practice, with the focus on the Netherlands. Despite the lack of evidence from randomized controlled trials, currently available data suggest especially beneficial effects of normothermic regional perfusion on biliary complications and ischemic cholangiopathy after liver transplantation. For ex vivo machine perfusion in kidney transplantation, hypothermic machine perfusion has proven to be beneficial over static cold storage in a randomized controlled trial, while normothermic machine perfusion is currently under investigation. For ex vivo machine perfusion in liver transplantation, normothermic machine perfusion has proven to reduce discard rates and early allograft dysfunction. In response to clinical studies, hypothermic machine perfusion for deceased donor kidneys has already been implemented as standard of care in the Netherlands.

Use of ex vivo normothermic machine perfusion after normothermic regional perfusion to salvage a poorly perfused DCD kidney

Normothermic regional perfusion (NRP) and normothermic machine perfusion (NMP) have both been used in the procurement and conditioning of abdominal organs from donation after circulatory death donors with reported improved outcomes for the recipients. Here, we describe an unusual case of a kidney that underwent NMP after NRP. After 2 hours of abdominal NRP, the intra-abdominal organs were cold flushed in situ. The liver and right kidney were well flushed, but the left kidney was poorly flushed. Further attempts to clear the left kidney by flushing on the backtable were unsuccessful, and the kidney was thought to be unsuitable for transplant. The left kidney then underwent a 1-hour period of NMP using a red cell-based perfusate. During NMP, the kidney met previously described quality assurance criteria for transplant with good global perfusion and adequate renal blood flow and urine production. The kidney was transplanted into a suitable recipient who had slow early graft function but did not require dialysis posttransplant. The recipient was discharged 6 days posttransplant, and the serum creatinine level was 160 μmol/L (1.8 mg/dL) at 2 months posttransplant.

Outcomes of DCD kidneys recovered for transplantation with versus without pre-mortem heparin administration

BACKGROUND

Pre-mortem heparin administration during donation after circulatory death (DCD) organ recovery may be particularly important to improve perfusion and prevent graft thrombosis. However, pre-mortem heparin administration is not universally practiced in the US and scarce data exist regarding its efficacy.

METHODS

Using a national transplant registry data, we identified DCD kidneys recovered for transplantation from January 1, 2003, to March 10, 2017, and examined discard and outcomes after transplantation using bivariate and multivariable analyses. Organs with unknown or missing donor heparin status (n = 193), seropositive HIV (n = 10), HTLV (n = 33), hepatitis B (n = 26), or hepatitis C (n = 648) were excluded.

RESULTS

Of 24 861 DCD kidneys recovered with (n = 22 557) or without pre-mortem heparin administration (n = 2304), discard occurred in 19.1% and 20.8%, respectively (P = 0.05). On multivariate analysis, heparin use was not associated with discard (aOR 1.02, 95% CI 0.89-1.17, P = 0.820). Overall graft survival of no-heparin (n = 1791) vs heparin groups (n = 17 968) was similar on univariate and multivariate analysis (aHR 0.98, 95% CI 0.87-1.09, P = 0.640).

CONCLUSION

DCD kidneys from donors that have not received pre-mortem heparin administration have acceptable transplant outcomes and are not associated with discard.

In situ normothermic perfusion of livers in controlled circulatory death donation may prevent ischemic cholangiopathy and improve graft survival

Livers from controlled donation after circulatory death (DCD) donors suffer a higher incidence of nonfunction, poor function, and ischemic cholangiopathy. In situ normothermic regional perfusion (NRP) restores a blood supply to the abdominal organs after death using an extracorporeal circulation for a limited period before organ recovery. We undertook a retrospective analysis to evaluate whether NRP was associated with improved outcomes of livers from DCD donors. NRP was performed on 70 DCD donors from whom 43 livers were transplanted. These were compared with 187 non-NRP DCD donor livers transplanted at the same two UK centers in the same period. The use of NRP was associated with a reduction in early allograft dysfunction (12% for NRP vs. 32% for non-NRP livers, P = .0076), 30-day graft loss (2% NRP livers vs. 12% non-NRP livers, P = .0559), freedom from ischemic cholangiopathy (0% vs. 27% for non-NRP livers, P < .0001), and fewer anastomotic strictures (7% vs. 27% non-NRP, P = .0041). After adjusting for other factors in a multivariable analysis, NRP remained significantly associated with freedom from ischemic cholangiopathy (P < .0001). These data suggest that NRP during organ recovery from DCD donors leads to superior liver outcomes compared to conventional organ recovery.

Survival advantage for patients accepting the offer of a circulatory death liver transplant

BACKGROUND & AIMS

Donation after circulatory death (DCD) in the UK has tripled in the last decade. However, outcomes following DCD liver transplantation are worse than for donation after brainstem death (DBD) liver transplants. This study examines whether a recipient should accept a "poorer quality" DCD organ or wait longer for a "better" DBD organ.

METHODS

Data were collected on 5,825 patients who were registered on the elective waiting list for a first adult liver-only transplant and 3,949 patients who received a liver-only transplant in the UK between 1 January 2008 and 31 December 2015. Survival following deceased donor liver transplantation performed between 2008 and 2015 was compared by Cox regression modelling to assess the impact on patient survival of accepting a DCD liver compared to deferring for a potential DBD transplant.

RESULTS

A total of 953 (23%) of the 3,949 liver transplantations performed utilised DCD donors. Five-year post-transplant survival was worse following DCD than DBD transplantation (69.1% [DCD] vs. 78.3% [DBD]; p <0.0001: adjusted hazard ratio [HR] 1.65; 95% CI 1.40-1.94). Of the 5,798 patients registered on the transplant list, 1,325 (23%) died or were removed from the list without receiving a transplant. Patients who received DCD livers had a lower risk-adjusted hazard of death than those who remained on the waiting list for a potential DBD organ (adjusted HR 0.55; 95% CI 0.47-0.65). The greatest survival benefit was in those with the most advanced liver disease (adjusted HR 0.19; 95% CI 0.07-0.50).

CONCLUSIONS

Although DCD liver transplantation leads to worse transplant outcomes than DBD transplantation, the individual's survival is enhanced by accepting a DCD offer, particularly for patients with more severe liver disease. DCD liver transplantation improves overall survival for UK listed patients and should be encouraged.

LAY SUMMARY

This study looks at patients who require a liver transplant to save their lives; this liver can be donated by a person who has died either after their heart has stopped (donation after cardiac death [DCD]) or after the brain has been injured and can no longer support life (donation after brainstem death [DBD]). We know that livers donated after brainstem death function better than those after cardiac death, but there are not enough of these livers for everyone, so we wished to help patients decide whether it was better for them to accept an early offer of a DCD liver than waiting longer to receive a "better" liver from a DBD donor. We found that patients were more likely to survive if they accepted the offer of a liver transplant as soon as possible (DCD or DBD), especially if their liver disease was very severe.

Donation after circulatory death and its expansion in Spain

PURPOSE OF REVIEW

Donation after circulatory death (DCD) is still performed in a limited number of countries. This article summarizes the development of DCD in Spain and presents recent Spanish contributions to gain knowledge on the potential benefits and the practical use of normothermic regional perfusion (nRP).

RECENT FINDINGS

DCD now contributes to 24% of deceased donors in Spain. The development of DCD has been based on an assessment of practices in the treatment of cardiac arrest and end-of-life care to accommodate the option of DCD; the creation of an adequate regulatory framework; and institutional support, professional training and public education. Appropriate posttransplant outcomes have been obtained with organs from both uncontrolled and controlled DCD donors. nRP is increasingly used, with preliminary data supporting improved results compared with other in-situ preservation/recovery approaches. Mobile teams with portable extracorporeal membrane oxygenation devices are making nRP possible in hospitals without these resources. To avoid the possibility of reestablishing brain circulation after the determination of death, a specific methodology has been validated.

SUMMARY

DCD has been successfully developed in Spain following a streamlined process. nRP may become a standard in DCD, although further evidence on the benefits of this technology is eagerly awaited.

Machine perfusion for liver transplantation in the era of marginal organs-New kids on the block

In the face of a critical organ shortage in the Western world, various strategies are employed to expand the donor pool for orthotopic liver transplantation (OLT). Among them is the transplantation of organs from extended criteria donors, a valuable source of liver allografts, however, characterized by potential risks for post-OLT complications and inferior outcomes. In recent years, machine perfusion (MP) of the explanted donor liver as well as regional perfusion techniques has witnessed significant advancements. Here, we aim to discuss different modes of dynamic organ preservation in OLT. These include hypothermic and normothermic MP, hypothermic oxygenated machine perfusion (HOPE), controlled oxygenated rewarming as well as regional perfusion protocols. Over recent years, multiple feasibility trials have demonstrated the clinical prospects of MP. In the context of OLT using organs from extended criteria donors, MP has numerous advantages compared to conventional cold storage, some of which include the preservation and reconditioning of borderline transplantable organs and the viability assessment of high-risk donor allografts. This review aims to address the topic of liver allograft MP, highlighting particularly the current trends in clinical applications and future perspectives. Furthermore, different approaches of liver storage and reconditioning are reviewed in the context of ongoing research.

Heart transplantation after the circulatory death; The ethical dilemma

Donors after brain death (DBD) have been the major source of organ donation due to good perfusion of the organs. However, owing to the mismatch in demand and supply of the organ donors and recipients, donors after circulatory death (DCDDs) has increased recently all over the world. Kidneys, liver, and lungs are being used for transplantation from DCDDs. Recently, heart transplantation from DCDDs has been started, which is under the firestorm of scrutiny by the ethicists. The ethical dilemma revolves around the question whether the donors are actually dead when they are declared dead by cardiocirculatory death criteria for organ procurement. The subsequent literature review addresses all the perspectives by differentiating between the donation methods known as DBDs and DCDDs, explaining the implications of the dead-donor rule on the organ donation pool, and categorizing the determinants of death leading to separation of the arguments under the two methods of donations.

An analysis of heart donation after circulatory determination of death

BACKGROUND

Heart donation after circulatory determination of death (DCDD) has provoked ethical debate focused primarily on whether heart DCDD donors are dead when death is declared and when organs are procured.

OBJECTIVE AND DESIGN

We rigorously analyse whether four heart DCDD programmes (Cape Town, Denver, Australia, Cambridge) respect the dead donor rule (DDR), according to six criteria of death: irreversible cessation of all bodily cells function (or organs), irreversible cessation of heart function, irreversible cessation of circulation, permanent cessation of circulation, irreversible cessation of brain function and permanent cessation of brain function.

CONCLUSIONS

Only death criteria based on permanency are compatible with the DDR under two conditions: (1) a minimum stand-off period of 5 min to ensure that autoresuscitation is impossible and that all brain functions have been lost and (2) no medical intervention is undertaken that might resume bodily or brain circulation. By our analysis, only the Australia heart DCDD programme using a stand-off period of 5 min respects the DDR when the criteria of death are based on permanency.

Challenges and advances in optimizing liver allografts from donation after circulatory death donors

In recent years, there has been a shift in the donor demographics with an increase in donation after circulatory death (DCD). Livers obtained from DCD donors are known to have poorer outcomes when compared to donors after brainstem death and currently only a small proportion of DCD livers are used. This review outlines the recent technological developments in liver DCD donation, including clinical studies using normothermic regional perfusion and extracorporal machine perfusion of livers from DCD donors.

Organ preservation review: history of organ preservation

PURPOSE OF REVIEW

To summarize the history of organ preservation and place into this context the current trends in preservation.

RECENT FINDINGS

Multiple large retrospective studies have analyzed cold preservation solutions in an attempt to determine superiority with largely negative results. Experimental and some clinical studies have examined machine perfusion of procured grafts, in both hypothermic and normothermic contexts with variable, but promising, results. Lastly, there are experimental efforts to evaluate mesenchymal stem cell therapy on rehabilitation of marginal donor organs.

SUMMARY

New trends in organ preservation may soon translate into more efficient use of the limited donor pool.

Molecular pathways in protecting the liver from ischaemia/reperfusion injury: a 2015 update

Ischaemia/reperfusion injury is an important cause of liver damage during surgical procedures such as hepatic resection and liver transplantation, and represents the main cause of graft dysfunction post-transplantation. Molecular processes occurring during hepatic ischaemia/reperfusion are diverse, and continuously include new and complex mechanisms. The present review aims to summarize the newest concepts and hypotheses regarding the pathophysiology of liver ischaemia/reperfusion, making clear distinction between situations of cold and warm ischaemia. Moreover, the most updated therapeutic strategies including pharmacological, genetic and surgical interventions, as well as some of the scientific controversies in the field are described.

[Renal transplantation using a Maastricht category III non-heartbeating donor: First French experience and review of the literature]

In 2015, Annecy Hospital was the first French hospital to perform non-heartbeating organ donation from a Maastricht category III donor (patient awaiting cardiac arrest after withdrawal of treatment). Non-heartbeating organ donation (NHBD), performed in France since 2006, had initially excluded this category, due to ethical questions concerning end of life and treatment withdrawal, as well as technical specificities linked to this procedure. Grenoble University Hospital and Edouard-Herriot Hospital in Lyon then performed the first kidney transplants, with satisfactory outcomes in both recipients. This article presents the details and results of this new experience, challenging both on a deontological and organizational level. Functional outcomes of kidney grafts from NHBD are now well known in the literature and confirm their benefit for patients, with similar results to those from heartbeating donors (HBD). International experiences concerning specifically Maastricht category III NHBD are encouraging and promising.

Machine perfusion in liver transplantation as a tool to prevent non-anastomotic biliary strictures: Rationale, current evidence and future directions

The high incidence of non-anastomotic biliary strictures (NAS) after transplantation of livers from extended criteria donors is currently a major barrier to widespread use of these organs. This review provides an update on the most recent advances in the understanding of the etiology of NAS. These new insights give reason to believe that machine perfusion can reduce the incidence of NAS after transplantation by providing more protective effects on the biliary tree during preservation of the donor liver. An overview is presented regarding the different endpoints that have been used for assessment of biliary injury and function before and after transplantation, emphasizing on methods used during machine perfusion. The wide spectrum of different approaches to machine perfusion is discussed, including the many different combinations of techniques, temperatures and perfusates at varying time points. In addition, the current understanding of the effect of machine perfusion in relation to biliary injury is reviewed. Finally, we explore directions for future research such as the application of (pharmacological) strategies during machine perfusion to further improve preservation. We stress the great potential of machine perfusion to possibly expand the donor pool by reducing the incidence of NAS in extended criteria organs.

Cyclic Helix B Peptide in Preservation Solution and Autologous Blood Perfusate Ameliorates Ischemia-Reperfusion Injury in Isolated Porcine Kidneys

There is a critical need to better preserve isolated organs before transplantation. We developed a novel nonerythropoiesis cyclic helix B peptide (CHBP) derived from erythropoietin, which has potent tissue protection and prolonged serum stability. The renoprotection and potential mechanism of CHBP were evaluated in a kidney preservation model.

MATERIALS AND METHODS

Porcine kidneys (n = 5) subjected to 20-minute warm ischemia were retrieved and flushed with hyperosmolar citrate to mimic deceased donation. The kidneys and autologous blood ± 10.56 nmol/L CHBP were placed in cold storage (CS) for 18 hours. These kidneys were then normothermically hemoreperfused for 3 hours using an isolated organ perfusion system. The renal function and structure, apoptosis, inflammation, and expression of caspase-3 and heat shock protein 70 (HSP70) were assessed.

RESULTS

Cyclic helix B peptide significantly increased the renal blood flow, oxygen consumption, and urine output during reperfusion, but decreased serum potassium and renal tissue damage. Apoptotic cells were significantly decreased in the tubular areas, but increased in the lumens and interstitial areas in the post-CS and postreperfused kidneys, whereas myeloperoxidase+ cells were reduced. In addition, the expression of both caspase-3 precursor and active subunits was downregulated by CHBP in reperfused kidneys. However, HSP70 was upregulated in the post-CS and postreperfused kidneys treated with CHBP.

CONCLUSIONS

Cyclic helix B peptide administered into preservation and reperfusion solutions ameliorated renal ischemia-reperfusion injury, which might be associated with decreased apoptosis, inflammation and caspase-3, but increased HSP70. This novel preservation approach using CHBP may be applied in a porcine kidney transplant model and potential human donor kidney preservation.

In situ normothermic regional perfusion for controlled donation after circulatory death--the United Kingdom experience

Organs recovered from donors after circulatory death (DCD) suffer warm ischemia before cold storage which may prejudice graft survival and result in a greater risk of complications after transplant. A period of normothermic regional perfusion (NRP) in the donor may reverse these effects and improve organ function. Twenty-one NRP retrievals from Maastricht category III DCD donors were performed at three UK centers. NRP was established postasystole via aortic and caval cannulation and maintained for 2 h. Blood gases and biochemistry were monitored to assess organ function. Sixty-three organs were recovered. Forty-nine patients were transplanted. The median time from asystole to NRP was 16 min (range 10-23 min). Thirty-two patients received a kidney transplant. The median cold ischemia time was 12 h 30 min (range 5 h 25 min-18 h 22 min). The median creatinine at 3 and 12 months was 107 µmol/L (range 72-222) and 121 µmol/L (range 63-157), respectively. Thirteen (40%) recipients had delayed graft function and four lost the grafts. Eleven patients received a liver transplant. The first week median peak ALT was 389 IU/L (range 58-3043). One patient had primary nonfunction. Two combined pancreas-kidney transplants, one islet transplant and three double lung transplants were performed with primary function. NRP in DCD donation facilitates organ recovery and may improve short-term outcomes.