A metabolic approach during normothermic regional perfusion in uncontrolled donors after circulatory death-A pilot study

An extensive evaluation of hepatic markers of damage and regeneration in controlled and uncontrolled donation after circulatory death

Livers from donations after circulatory death (DCDs) are very sensitive to ischemia/reperfusion injury and thus need careful reconditioning, such as normothermic regional perfusion (NRP). So far, its impact on DCDs has not been thoroughly investigated. This pilot cohort study aimed to explore the NRP impact on liver function by evaluating dynamic changes of circulating markers and hepatic gene expression in 9 uncontrolled DCDs (uDCDs) and 10 controlled DCDs. At NRP start, controlled DCDs had lower plasma levels of inflammatory and liver damage markers, including α-glutathione s-transferase, sorbitol-dehydrogenase, malate dehydrogenase 1, liver-type arginase-1, and keratin-18, but higher levels of osteopontin, sFas, flavin mononucleotide, and succinate than uDCDs. During 4-hour NRP, some damage and inflammatory markers increased in both groups, while IL-6, HGF, and osteopontin increased only in uDCDs. At the NRP end, the tissue expression of early transcriptional regulators, apoptosis, and autophagy mediators was higher in uDCDs than in controlled DCDs. In conclusion, despite initial differences in liver damage biomarkers, the uDCD group was characterized by a major gene expression of regenerative and repair factors after the NRP procedure. Correlative analysis among circulating/tissue biomarkers and the tissue congestion/necrosis degree revealed new potential candidate biomarkers.

cDCD organ donation pathway of Romagna Local Health Authority: strategic planning, organizational management, and results

The introduction of pathways to enrol deceased donors after cardio-circulatory confirmation of death (donation after circulatory death, DCD) is expanding in many countries to face the shortage of organs for transplantation. The implementation of normothermic regional reperfusion (NRP) with warm oxygenated blood is a strategy to manage in-situ the organs of DCD donors. This approach, an alternative to in-situ cold preservation, and followed by prompt retrieval and cold static storage and/or ex-vivo machine perfusion (EVMP), could be limited to abdominal organs (A-NRP) or extended to the thorax (thoraco-abdominal, TA-NRP. NRP is also referred to as extracorporeal interval support for organ retrieval (EISOR). The use of EISOR is increasing in Europe, even if variably regulated. A-NRP has been demonstrated to be effective in decreasing the risk associated with transplantation of abdominal organs from DCD donors, and was recommended by the European Society for Organ Transplantation (ESOT) in a recent consensus document. We aim to explain how we select the candidates for DCD, to describe our regionalized model for implementing EISOR provision, and to introduce the health care professionals involved in this complex process, with their strictly defined roles, responsibilities, and boundaries. Finally, we report the results of our program, recruiting cDCD donors over a large network of hospitals, all pertaining to a Local Health Authority (Azienda Unità Sanitaria Locale, AUSL) in Romagna, Italy.

Normothermic regional perfusion in liver transplantation from donation after cardiocirculatory death: Technical, biochemical, and regulatory aspects and review of literature

BACKGROUND

Organs from donation after circulatory death (DCD) are increasingly used for liver transplantation, due to the persisting organ shortage and waiting list mortality. However, the use of DCD grafts is still limited by the inferior graft survival rate and the increased risk of primary non-function and biliary complications when compared to brain death donors' grafts.

METHODS

Abdominal normothermic regional perfusion with extracorporeal membrane oxygenation (ECMO) is an in situ preservation strategy. which may mitigate ischemia-reperfusion injuries. and has been proposed to restore blood perfusion after the determination of death thus optimizing liver function before implantation.

RESULTS

In this systematic review, we highlighted the clinical evidence supporting the use of normothermic regional perfusion in DCD liver underlying the pathophysiological mechanisms, and technical, logistic, and regulatory aspects.

CONCLUSIONS

Despite the lack of properly designed, prospective, randomized trials, the current available data suggest beneficial effects of normothermic regional perfusion on clinical outcomes after liver transplantation.

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.

Transplantation of kidneys after normothermic perfusion: A single center experience

BACKGROUND

In order to expand the pool of usable donors from circulatory death (DCD) there is increasing interest in normothermic regional perfusion (NRP) to assess and improve liver viability.^1,2 NRP may also improve outcomes in kidney transplantation.We present our single center experience of outcomes in imported kidneys following NRP.

METHODS

Data was obtained from a prospectively maintained database between December 2012 and September 2018. Primary endpoints were incidence of delayed graft function (DGF) and estimated glomerular filtration rate (eGFR).

RESULTS

Six-hundred and thirty-two decease donor kidneys were transplanted, 229 from DCD donors, 29 of which had NRP. The DGF rate was lower for NRP versus DCD (six of 29, 20.7% vs. 70 of 200, 35.0%) with reduced duration of DGF. Multivariate analysis demonstrated transplant type to be a statistically significant independent predictor of eGFR at 7 and 14 days. Early transplant function in NRP kidneys was comparable to DBD. There were no graft losses within 30 days in the NRP group. One-year graft loss rate was 3.4% for NRP and 6.0% for standard DCD.

CONCLUSION

This data suggests NRP is safe, and reduces rates of DGF and improves early renal transplant function.

Hemolytic uremic syndrome and kidney transplantation in uncontrolled donation after circulatory death (DCD): A two-case report

Background: Hemolytic uremic syndrome (HUS) is a rare disease characterized by microangiopathic hemolysis, thrombocytopenia, and renal involvement. Complement-mediated atypical HUS (aHUS) is a result of genetic defects in the alternative complement pathway components or regulators. The introduction of eculizumab has improved renal and overall survival of aHUS patients. Nowadays, given organ shortage, it is necessary to consider kidney transplantation (KT) even in protocols with a high risk of HUS recurrence, such as from donation after circulatory death (DCD) donors. Here, we describe two patients with HUS who underwent a KT from an uncontrolled DCD (uDCD). Case summary: The first patient, affected by aHUS due to a heterozygous deletion in CFHR3-CFHR1 and a novel heterozygous variant in CFHR5 gene, underwent a KT with eculizumab prophylaxis. The patient did not experience a post-transplant aHUS recurrence. The second patient, who experienced an HUS episode characterized by a hypertensive crisis and with no underlying mutations in complement system genes, underwent a KT without eculizumab prophylaxis. At day 5, anti-complement treatment commenced due to hematological signs of thrombotic microangiopathy (TMA). After the introduction of eculizumab, we observed a stabilization of kidney function and hematological remission. Conclusion: We present herein two different patients with HUS who both underwent successful KT from uDCD donation under the umbrella of eculizumab therapy. Taking into account the importance of increasing the number of organs available for transplantation, uDCD could represent an additional resource in this subset of HUS patients.

Hypothermic Oxygenated Perfusion Versus Normothermic Regional Perfusion in Liver Transplantation From Controlled Donation After Circulatory Death: First International Comparative Study

OBJECTIVE

To compare HOPE and NRP in liver transplantation from cDCD.

SUMMARY OF BACKGROUND DATA

Liver transplantation after cDCD is associated with higher rates of graft loss. Dynamic preservation strategies such as NRP and HOPE may offer safer use of cDCD grafts.

METHODS

Retrospective comparative cohort study assessing outcomes after cDCD liver transplantation in 1 Swiss (HOPE) and 6 French (NRP) centers. The primary endpoint was 1-year tumor-death censored graft and patient survival.

RESULTS

A total of 132 and 93 liver grafts were transplanted after NRP and HOPE, respectively. NRP grafts were procured from younger donors (50 vs 61 years, P < 0.001), with shorter functional donor warm ischemia (22 vs 31 minutes, P < 0.001) and a lower overall predicted risk for graft loss (UK-DCD-risk score 6 vs 9 points, P < 0.001). One-year tumor-death censored graft and patient survival was 93% versus 86% (P = 0.125) and 95% versus 93% (P = 0.482) after NRP and HOPE, respectively. No differences in non-anastomotic biliary strictures, primary nonfunction and hepatic artery thrombosis were observed in the total cohort and in 32 vs. 32 propensity score-matched recipients CONCLUSION:: NRP and HOPE in cDCD achieved similar post-transplant recipient and graft survival rates exceeding 85% and comparable to the benchmark values observed in standard DBD liver transplantation. Grafts in the HOPE cohort were procured from older donors and had longer warm ischemia times, and consequently achieved higher utilization rates. Therefore, randomized controlled trials with intention-to-treat analysis are needed to further compare both preservation strategies, especially for high-risk donor-recipient combinations.

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.

Delayed graft function and perfusion parameters of kidneys from uncontrolled donors after circulatory death

Better preservation and evaluation of kidneys from donors after circulatory death serve to increase the number of kidneys available for transplantation and hypothermic machine perfusion has been shown to decrease ischemia reperfusion injury and delayed graft function. Data on relation between hemodynamic parameters during hypothermic machine perfusion and delayed graft function in kidneys from donors after circulatory death are so far scarce and not univocal. We aimed at assessing whether hemodynamic parameters measured during hypothermic machine perfusion (flow, mean perfusion pressure, and renal resistance) are associated with delayed graft function in 26 kidneys retrieved from uncontrolled donors after circulatory death. In our series, the incidence of delayed graft function was 57.7% (15/26). Recipients who developed delayed graft function had a longer warm ischemic time (p = 0.04). All hemodynamic parameters measured during hypothermic machine perfusion were comparable between recipients with delayed graft function and those without. According to our data, in kidneys from uncontrolled donors after circulatory death, a longer warm ischemic time (that is the overall time of no flow, as the sum of the no-flow and the no-touch period) is associated with delayed graft function. This finding underscores the pivotal role of ischemic injury in terms of absence of flow in affecting graft function. No association was detectable between hemodynamic parameters during hypothermic machine perfusion and the development of delayed graft function in our series.