Applicability and results of Maastricht type 2 donation after cardiac death liver transplantation

Role of Machine Perfusion in Liver Transplantation

Given the current severe shortage of available livers for transplantation, there is an urgent need to maximize the utilization of donor organs. One of the strategies to increase the number of available livers for transplantation is to improve organ utilization through the use of elderly, overweight, or organs donated after circulatory death. However, the utilization of these "marginal" organs was associated with an increased risk of early allograft dysfunction, primary nonfunction, ischemic biliary complications, or even re-transplantation. Ischemia-reperfusion injury is a key mechanism in the pathogenesis of these complications.

Organ Donation After Out-of-Hospital Cardiac Arrest: A Scientific Statement From the International Liaison Committee on Resuscitation

AIM OF THE REVIEW

Improving rates of organ donation among patients with out-of-hospital cardiac arrest who do not survive is an opportunity to save countless lives. The objectives of this scientific statement were to do the following: define the opportunity for organ donation among patients with out-of-hospital cardiac arrest; identify challenges and opportunities associated with organ donation by patients with cardiac arrest; identify strategies, including a generic protocol for organ donation after cardiac arrest, to increase the rate and consistency of organ donation from this population; and provide rationale for including organ donation as a key clinical outcome for all future cardiac arrest clinical trials and registries.

METHODS

The scope of this International Liaison Committee on Resuscitation scientific statement was approved by the International Liaison Committee on Resuscitation board and the American Heart Association, posted on ILCOR.org for public comment, and then assigned by section to primary and secondary authors. A unique literature search was completed and updated for each section.

RESULTS

There are a number of defining pathways for patients with out-of-hospital cardiac arrest to become organ donors; however, modifications in the Maastricht classification system need to be made to correctly identify these donors and to report outcomes with consistency. Suggested modifications to the minimum data set for reporting cardiac arrests will increase reporting of organ donation as an important resuscitation outcome. There are a number of challenges with implementing uncontrolled donation after cardiac death protocols, and the greatest impediment is the lack of legislation in most countries to mandate organ donation as the default option. Extracorporeal cardiopulmonary resuscitation has the potential to increase organ donation rates, but more research is needed to derive neuroprognostication rules to guide clinical decision-making about when to stop extracorporeal cardiopulmonary resuscitation and to evaluate cost-effectiveness.

CONCLUSIONS

All health systems should develop, implement, and evaluate protocols designed to optimize organ donation opportunities for patients who have an out-of-hospital cardiac arrest and failed attempts at resuscitation.

Organ Donation After Out-of-Hospital Cardiac Arrest: A Scientific Statement From the International Liaison Committee on Resuscitation

AIM OF THE REVIEW

Improving rates of organ donation among patients with out-of-hospital cardiac arrest who do not survive is an opportunity to save countless lives. The objectives of this scientific statement were to do the following: define the opportunity for organ donation among patients with out-of-hospital cardiac arrest; identify challenges and opportunities associated with organ donation by patients with cardiac arrest; identify strategies, including a generic protocol for organ donation after cardiac arrest, to increase the rate and consistency of organ donation from this population; and provide rationale for including organ donation as a key clinical outcome for all future cardiac arrest clinical trials and registries.

METHODS

The scope of this International Liaison Committee on Resuscitation scientific statement was approved by the International Liaison Committee on Resuscitation board and the American Heart Association, posted on ILCOR.org for public comment, and then assigned by section to primary and secondary authors. A unique literature search was completed and updated for each section.

RESULTS

There are a number of defining pathways for patients with out-of-hospital cardiac arrest to become organ donors; however, modifications in the Maastricht classification system need to be made to correctly identify these donors and to report outcomes with consistency. Suggested modifications to the minimum data set for reporting cardiac arrests will increase reporting of organ donation as an important resuscitation outcome. There are a number of challenges with implementing uncontrolled donation after cardiac death protocols, and the greatest impediment is the lack of legislation in most countries to mandate organ donation as the default option. Extracorporeal cardiopulmonary resuscitation has the potential to increase organ donation rates, but more research is needed to derive neuroprognostication rules to guide clinical decision-making about when to stop extracorporeal cardiopulmonary resuscitation and to evaluate cost-effectiveness.

CONCLUSIONS

All health systems should develop, implement, and evaluate protocols designed to optimise organ donation opportunities for patients who have an out-of-hospital cardiac arrest and failed attempts at resuscitation.

Multiorgan recovery in a cadaver body using mild hypothermic ECMO treatment in a murine model

BACKGROUND

Transplant candidates on the waiting list are increasingly challenged by the lack of organs. Most of the organs can only be kept viable within very limited timeframes (e.g., mere 4-6 h for heart and lungs exposed to refrigeration temperatures ex vivo). Donation after circulatory death (DCD) using extracorporeal membrane oxygenation (ECMO) can significantly enlarge the donor pool, organ yield per donor, and shelf life. Nevertheless, clinical attempts to recover organs for transplantation after uncontrolled DCD are extremely complex and hardly reproducible. Therefore, as a preliminary strategy to fulfill this task, experimental protocols using feasible animal models are highly warranted. The primary aim of the study was to develop a model of ECMO-based cadaver organ recovery in mice. Our model mimics uncontrolled organ donation after an "out-of-hospital" sudden unexpected death with subsequent "in-hospital" cadaver management post-mortem. The secondary aim was to assess blood gas parameters, cardiac activity as well as overall organ state. The study protocol included post-mortem heparin-streptokinase administration 10 min after confirmed death induced by cervical dislocation under full anesthesia. After cannulation, veno-arterial ECMO (V-A ECMO) was started 1 h after death and continued for 2 h under mild hypothermic conditions followed by organ harvest. Pressure- and flow-controlled oxygenated blood-based reperfusion of a cadaver body was accompanied by blood gas analysis (BGA), electrocardiography, and histological evaluation of ischemia-reperfusion injury. For the first time, we designed and implemented, a not yet reported, miniaturized murine hemodialysis circuit for the treatment of severe hyperkalemia and metabolic acidosis post-mortem.

RESULTS

BGA parameters confirmed profound ischemia typical for cadavers and incompatible with normal physiology, including extremely low blood pH, profound negative base excess, and enormously high levels of lactate. Two hours after ECMO implantation, blood pH values of a cadaver body restored from < 6.5 to 7.3 ± 0.05, pCO2 was lowered from > 130 to 41.7 ± 10.5 mmHg, sO2, base excess, and HCO3 were all elevated from below detection thresholds to 99.5 ± 0.6%, - 4 ± 6.2 and 22.0 ± 6.0 mmol/L, respectively (Student T test, p < 0.05). A substantial decrease in hyperlactatemia (from > 20 to 10.5 ± 1.7 mmol/L) and hyperkalemia (from > 9 to 6.9 ± 1.0 mmol/L) was observed when hemodialysis was implemented. On balance, the first signs of regained heart activity appeared on average 10 min after ECMO initiation without cardioplegia or any inotropic and vasopressor support. This was followed by restoration of myocardial contractility with a heart rate of up to 200 beats per minute (bpm) as detected by an electrocardiogram (ECG). Histological examinations revealed no evidence of heart injury 3 h post-mortem, whereas shock-specific morphological changes relevant to acute death and consequent cardiac/circulatory arrest were observed in the lungs, liver, and kidney of both control and ECMO-treated cadaver mice.

CONCLUSIONS

Thus, our model represents a promising approach to facilitate studying perspectives of cadaveric multiorgan recovery for transplantation. Moreover, it opens new possibilities for cadaver organ treatment to extend and potentiate donation and, hence, contribute to solving the organ shortage dilemma.

Donation after circulatory death: Novel strategies to improve the liver transplant outcome

In many countries, donation after circulatory death (DCD) liver grafts are used to overcome organ shortages; however, DCD grafts have been associated with an increased risk of complications and even graft loss after liver transplantation. The increased risk of complications is thought to correlate with prolonged functional donor warm ischaemia time. Stringent donor selection criteria and utilisation of in situ and ex situ organ perfusion technologies have led to improved outcomes. Additionally, the increased use of novel organ perfusion strategies has led to the possibility of reconditioning marginal DCD liver grafts. Moreover, these technologies enable the assessment of liver function before implantation, thus providing valuable data that can guide more precise graft-recipient selection. In this review, we first describe the different definitions of functional warm donor ischaemia time and its role as a determinant of outcomes after DCD liver transplantation, with a focus on the thresholds proposed for graft acceptance. Next, organ perfusion strategies, namely normothermic regional perfusion, hypothermic oxygenated perfusion, and normothermic machine perfusion are discussed. For each technique, clinical studies reporting on the transplant outcome are described, together with a discussion on the possible protective mechanisms involved and the functional criteria adopted for graft selection. Finally, we review multimodal preservation protocols involving a combination of more than one perfusion technique and potential future directions in the field.

Donor eligibility criteria and liver graft acceptance criteria during normothermic regional perfusion: A systematic review

Acceptance of liver grafts from donations after circulatory death (DCD) largely remains a "black box," particularly due to the unpredictability of the agonal phase. Abdominal normothermic regional perfusion (aNRP) can reverse ischemic injury early during the procurement procedure, and it simultaneously enables graft viability testing to unravel this black box. This review evaluates current protocols for liver viability assessment to decide upon acceptance or decline during aNRP. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline was used, and relevant literature databases were searched. The primary outcome consisted of criteria for liver graft viability assessment. Secondary outcomes included survival, primary nonfunction (PNF), early dysfunction, and biliary complications. A total of 14 articles were included in the analysis. In all protocols, a combination of criteria was used to assess suitability of the liver for transplantation. As many as 12 studies (86%) used macroscopic assessment, 12 studies (86%) used alanine transaminase (ALT) levels in perfusate, 9 studies (64%) used microscopic assessment, and 7 studies (50%) used lactate levels as assessment criteria. The organ utilization rate (OUR) was 16% for uncontrolled donation after circulatory death (uDCD) and 64% for controlled donation after circulatory death (cDCD). The most used acceptation criterion in uDCD is ALT level (31%), while in cDCD macroscopic aspect (48%) is most used. Regarding postoperative complications, PNF occurred in 13% (6%-25%) of uDCD livers and 3% (2%-4%) of cDCD livers. In uDCD, the 1-year graft and patient survival rates were 75% (66%-82%) and 82% (75%-88%). In cDCD, the 1-year graft and patient survival rates were 91% (89%-93%) and 93% (91%-94%), respectively. In conclusion, the currently used assessment criteria consist of macroscopic aspect and transaminase levels. The acceptance criteria should be tailored according to donor type to prevent an unacceptable PNF rate in uDCD and to increase the relatively modest OUR in cDCD.

Liver Transplantation in Sexagenarian Patients Using Grafts From Uncontrolled Circulatory Death Versus Grafts From Brain Death Donation

BACKGROUND

An increased number of older recipients underwent liver transplantation in recent years, and consequently needing to obtain more liver grafts. In order to increase this pool, in 2006, we initiated the use of livers from uncontrolled circulatory death (uDCD). We analyzed the use of uDCD livers in sexagenarian recipients and their effect on overall survival.

METHODS

A retrospective and comparative study was performed among 4 groups according to recipient age (less or greater than 60 years) and donor type (donor brain death [DBD] or uDCD): Group A: DBD livers in recipients aged <60 years (n = 169); Group B: uDCD livers in recipients aged <60 years (n = 36); Group C: DBD livers in recipients aged >60 years (n = 96); and Group D: uDCD livers in recipients aged >60 years(n = 39).

RESULTS

Intraoperative transfusion, biliary complications, primary non-function, acute rejection, chronic renal dysfunction, retransplantation, and mortality during follow-up (cardiovascular diseases in 3 patients, hepatitis C virus recurrence in 4 patients, and de novo malignancies in 3 patients) were significantly higher, and 5-year patient and graft survival was significantly lower in sexagenarian recipients. Bilirubin and packed red blood cells transfusion were risk factors for patient survival, whereas hepatocelular carcinoma, creatinine, and packed red blood cells transfusion were risk factors for patient survival. Recipient age (<60 years) was confirmed as protective factor for patient and graft survival, whereas the use of uDCD was not a risk factor for patient or graft survival.

CONCLUSIONS

Use of a uDCD liver did not demonstrate as a risk factor for patient and graft survival, and recipient age (<60 years) was a protective factor for patient and graft survival.

The role of extracorporeal membrane oxygenation in adult liver transplant patients: A qualitative systematic review of literature

BACKGROUND

A paucity of evidence exists regarding risks and benefits of extracorporeal membrane oxygenation (ECMO) in adult liver transplantation.

METHODS

This was a systematic review conducted from January 1, 2000 to April 24, 2020 of adult liver transplant recipients (pre- or post-transplant) and donors who underwent Veno-arterial or Veno-venous ECMO cannulation. Death was the primary outcome, with graft function and complications as secondary outcomes.

RESULTS

Forty-one articles were identified that fit criteria. A total of 183 donors were placed on ECMO, with recipient complication profiles and mortality that mirrored rates from standard criteria donors. Sixty-one recipients were placed on ECMO intraoperatively or postoperatively. Most patients experienced at least one complication with infections as the most common cause and minimal complications specifically related to ECMO use. Multisystem organ failure (MSOF) and infections were more common among liver recipients who died compared to those who survived. Overall mortality at 90 days was 45.9%. Causes of death were most commonly MSOF and infections.

CONCLUSIONS

ECMO use in adult liver transplantation is a useful adjunct. Recipient morbidity and mortality from donors placed on ECMO parallel that of recipients from standard criteria donors, and morbidity and mortality of recipients placed on ECMO are similar to other ECMO populations.

Improved short-term outcomes of kidney transplants in controlled donation after the circulatory determination of death with the use of normothermic regional perfusion

Normothermic regional perfusion (NRP) allows the in situ perfusion of organs with oxygenated blood in donation after the circulatory determination of death (DCDD). We aimed at evaluating the impact of NRP on the short-term outcomes of kidney transplants in controlled DCDD (cDCDD). This is a multicenter, nationwide, retrospective study comparing cDCDD kidneys obtained with NRP versus the standard rapid recovery (RR) technique. During 2012-2018, 2302 cDCDD adult kidney transplants were performed in Spain using NRP (n = 865) or RR (n = 1437). The study groups differed in donor and recipient age, warm, and cold ischemic time and use of ex situ machine perfusion. Transplants in the NRP group were more frequently performed in high-volume centers (≥90 transplants/year). Through matching by propensity score, two cohorts with a total of 770 patients were obtained. After the matching, no statistically significant differences were observed between the groups in terms of primary nonfunction (p = .261) and mortality at 1 year (p =  .111). However, the RR of kidneys was associated with a significantly increased odds of delayed graft function (OR 1.97 [95% CI 1.43-2.72]; p < .001) and 1-year graft loss (OR 1.77 [95% CI 1.01-3.17]; p = .034). In conclusion, compared with RR, NRP appears to improve the short-term outcomes of cDCDD kidney transplants.

How to Preserve Liver Grafts From Circulatory Death With Long Warm Ischemia? A Retrospective Italian Cohort Study With Normothermic Regional Perfusion and Hypothermic Oxygenated Perfusion

BACKGROUND

Donation after circulatory death (DCD) in Italy, given its 20-min stand-off period, provides a unique bench test for normothermic regional perfusion (NRP) and dual hypothermic oxygenated machine perfusion (D-HOPE).

METHODS

We coordinated a multicenter retrospective Italian cohort study with 44 controlled DCD donors, who underwent NRP, to present transplant characteristics and results. To rank our results according to the high donor risk, we matched and compared a subgroup of 37 controlled DCD livers, preserved with NRP and D-HOPE, with static-preserved controlled DCD transplants from an established European program.

RESULTS

In the Italian cohort, D-HOPE was used in 84% of cases, and the primary nonfunction rate was 5%. Compared with the matched comparator group, the NRP + D-HOPE group showed a lower incidence of moderate and severe acute kidney injury (stage 2: 8% versus 27% and stage 3: 3% versus 27%; P = 0.001). Ischemic cholangiopathy remained low (2-y proportion free: 97% versus 92%; P = 0.317), despite the high-risk profile resulting from the longer donor warm ischemia in Italy (40 versus 18 min; P < 0.001).

CONCLUSIONS

These data suggest that NRP and D-HOPE yield good results in DCD livers with prolonged warm ischemia.

Clinical Utility and Evolution of Donor Serum Lactate During Normothermic Regional Perfusion in Uncontrolled Donation After Circulatory Death

BACKGROUND

Kidney transplantation from uncontrolled donor after circulatory death (uDCD) showed a higher incidence of delayed graft function and primary failure. The aim of this study was to study basal and kinetic evolution of lactate values in uDCD preserved on normothermic regional perfusion (NRP) as a predictive factor of kidney suitability exposed to prolong ischemic conditions.

METHODS

Descriptive and prospective study of a cohort of out-of-hospital cardiac arrest patients admitted to the emergency room as potential uDCD. Donors meeting the inclusion criteria were preserved on NRP for at least 2 hours before procurement. Serum lactate levels were determined at arrival as basal level and at 30 minutes intervals and compared with adequate renal perfusion in the operating room (OR).

RESULTS

Forty-five donors met inclusion criteria. Of these, 38 went to the OR (84.5%). No differences were found in basal lactate between accepted and rejected kidneys (203.08 ± 59.21 vs 175.43 ± 75.32 mg/dL, respectively); neither lactate, hematologic, hepatic transaminases, creatinine, or blood gas analysis sequential values evolved while on NRP. Lactate receiver operating characteristic curve failed to predict viability at different time points and did not correlate with the macroscopic kidney poor perfusion in the OR.

CONCLUSIONS

The baseline and kinetic evolution of plasma lactate values while on NRP, were not useful tools to predict the final OR kidney viability owing to previous severe ischemic insult.

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.

Regulations and Procurement Surgery in DCD Liver Transplantation: Expert Consensus Guidance From the International Liver Transplantation Society

Donation after circulatory death (DCD) donors are an increasingly more common source of livers for transplantation in many parts of the world. Events that occur during DCD liver recovery have a significant impact on the success of subsequent transplantation. This working group of the International Liver Transplantation Society evaluated current evidence as well as combined experience and created this guidance on DCD liver procurement. Best practices for the recovery and transplantation of livers arising through DCD after euthanasia and organ procurement with super-rapid cold preservation and recovery as well as postmortem normothermic regional perfusion are described, as are the use of adjuncts during DCD liver procurement.

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.

Liver transplantation for hepatocellular carcinoma using grafts from uncontrolled circulatory death donation

Controversy exists regarding whether the rate of hepatocellular carcinoma (HCC) recurrence after orthotopic liver transplantation (OLT) differs when using livers from donation after controlled circulatory death (DCD) versus livers from donation after brain death (DBD). The aim of this cohort study was to analyze rates of HCC recurrence, patient survival, and graft survival after OLT for HCC, comparing recipients of DBD livers (n = 103) with recipients of uncontrolled DCD livers (uDCD; n = 41). No significant differences in tumor size, tumor number, serum alpha-fetoprotein, proportion of patients within Milan criteria, or pre-OLT bridging therapies were identified between groups, although the waitlist period was significantly shorter in the uDCD group (p = 0.040). HCC recurrence was similar between groups. Patient survival was similar between groups, but graft survival was lower in the uDCD group. Multivariate analysis identified recipient age (p = 0.031), pre-OLT bridging therapy (p = 0.024), and HCC recurrence (p = 0.048) as independent risk factors for patient survival and pre-OLT transarterial chemoembolization (p = 0.045) as the single risk factor for HCC recurrence. In conclusion, similar patient survival and lower graft survival were observed in the uDCD group. However, the use of uDCD livers appears to be justified due to a shorter waitlist time, and lower waitlist dropout and HCC recurrence rates.

Donation after circulatory death and liver transplantation: a cohort study

Donations after circulatory death (DCD) are still challenging in Italy because of prolonged ischemia time (tWIT) due to the law and logistical issues. This cohort study was primarily aimed at assessing the association between successful transplantation and DCD types in the North Italy Transplant program. Adjusted risk ratios (RR) and 95% confidence intervals (CIs) for type III versus type II DCD were estimated using a Poisson regression model with a robust error variance. All consecutive DCD between 2008 and 2020 were included. Among 142 DCD, 102 were eligible for liver donation, and 96 were proposed: 68/69 (99%) and 28/33 (85%) type III and II DCD, respectively. Sixty-nine livers were recovered, 51/68 (75%) from type III and 18/28 (64%) from type II DCD, respectively (RR: 1.18; 95% CI: 0.87-1.60). After ex-vivo perfusion, 50/68 (74%) and 14/28 (50%) livers from type III and type II DCD were transplanted (RR: 1.49; 95% CI: 1.01-2.19). The estimate decreased after further controlling for tWIT (RR: 1.11; 95% CI: 0.55-2.24). Five patients (7.8%) experienced a PNF, 3/50 and 2/14 from type III and type II DCD, respectively. Type III DCD livers were more likely to be transplanted than type II. Warm ischemia time might explain this difference.

[Adult advanced life support]

These European Resuscitation Council Advanced Life Support guidelines are based on the 2020 International Consensus on Cardiopulmonary Resuscitation Science with Treatment Recommendations. This section provides guidelines on the prevention of and ALS treatments for both in-hospital cardiac arrest and out-of-hospital cardiac arrest.

European Resuscitation Council Guidelines 2021: Adult advanced life support

These European Resuscitation Council Advanced Life Support guidelines, are based on the 2020 International Consensus on Cardiopulmonary Resuscitation Science with Treatment Recommendations. This section provides guidelines on the prevention of and ALS treatments for both in-hospital cardiac arrest and out-of-hospital cardiac arrest.

Effect on the donor lungs of using abdominal normothermic regional perfusion in controlled donation after circulatory death

OBJECTIVES

Controlled donation after circulatory death (cDCD) donors are becoming a common source of organs for transplantation globally. However, the graft survival rate of cDCD abdominal organs is inferior to that of organs from brain-dead donors. The rapid retrieval (RR) technique is used by most donor organ procurement teams. The abdominal normothermic regional perfusion (A-NRP) technique has been implemented to minimize warm ischaemic damage to the abdominal organs. However, there is limited information on the effect of A-NRP on the quality of the donor lungs. This study aimed to compare lung transplantation outcomes using lungs procured from cDCD donors using the A-NRP and abdominal RR techniques.

METHODS

A single-centre retrospective analysis of consecutive transplant recipients of cDCD lungs from June 2013 to December 2019 was performed. The recipients were divided into 2 cohorts according to the abdominal procurement technique used. The recipient and donor characteristics (age, sex, cause of brain injury, warm ischaemic time, diagnosis, lung allocation score and other factors), incidence of primary graft dysfunction and early survival were monitored.

RESULTS

Twenty-eight consecutive lung transplantation recipients were identified (median age 59 years; 61% male); 14 recipients received lungs using the A-NRP and 14 using abdominal RR for abdominal organ retrieval. There were no significant differences in the baseline characteristics, primary graft dysfunction (P = 0.70), hospital mortality (P = 1.0) and 1-year survival rate (P = 1.0) between the 2 groups.

CONCLUSIONS

No difference was observed in lung transplantation outcomes irrespective of the abdominal organ procurement technique used (A-NRP or abdominal RR).

Incidence and risk factors of primary non-function after liver transplantation using grafts from uncontrolled donors after circulatory death

BACKGROUND

Graft primary non-function (PNF) is the most severe complication after orthotopic liver transplantation (OLT) and is frequently associated with livers from uncontrolled circulatory death (uDCD).

METHODS

We reviewed retrospectively the incidence, risk factors, and outcome of patients showing PNF after receiving uDCD liver grafts. The series comprises 75 OLT performed during 11 years.

RESULTS

The incidence of PNF using uDCD livers was 8%. We compared patients who developed PNF (n = 6) vs. patients without PNF (n = 69). Mean pump flow of donors during normothermic regional perfusion (NRP) was significantly lower in PNF (p = .032). Day 1 post-OLT levels of transaminases and the incidence of renal complications and postoperative mortality were also significantly higher in the PNF group, but 5-year patient survival was similar in both groups (66.7% in PNF and 68.5% in non-PNF). All PNF patients underwent re-OLT, and 2 died. PNF incidence has decreased in the last 5-years. Binary logistic regression analysis confirmed final ALT value >4 times the normal value as risk factor for PNF, and median donor pump flow >3700 ml/min as protective effect.

CONCLUSIONS

Adequate donor pump flow during NRP was a protective.

Part 7: Systems of Care: 2020 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care

Survival after cardiac arrest requires an integrated system of people, training, equipment, and organizations working together to achieve a common goal. Part 7 of the 2020 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care focuses on systems of care, with an emphasis on elements that are relevant to a broad range of resuscitation situations. Previous systems of care guidelines have identified a Chain of Survival, beginning with prevention and early identification of cardiac arrest and proceeding through resuscitation to post-cardiac arrest care. This concept is reinforced by the addition of recovery as an important stage in cardiac arrest survival. Debriefing and other quality improvement strategies were previously mentioned and are now emphasized. Specific to out-of-hospital cardiac arrest, this Part contains recommendations about community initiatives to promote cardiac arrest recognition, cardiopulmonary resuscitation, public access defibrillation, mobile phone technologies to summon first responders, and an enhanced role for emergency telecommunicators. Germane to in-hospital cardiac arrest are recommendations about the recognition and stabilization of hospital patients at risk for developing cardiac arrest. This Part also includes recommendations about clinical debriefing, transport to specialized cardiac arrest centers, organ donation, and performance measurement across the continuum of resuscitation situations.

Abdominal Normothermic Regional Perfusion in Donation After Circulatory Death: A Systematic Review and Critical Appraisal

BACKGROUND

Abdominal normothermic regional perfusion (aNRP) for donation after circulatory death is an emerging organ preservation technique that might lead to increased organ utilization per donor by facilitating viability testing, improving transplant outcome by early reversal of ischemia, and decreasing the risk of unintentional surgical damage. The aim of the current review is to evaluate the recent literature on the added value of aNRP when compared to local standard perfusion technique.

METHODS

The Preferred Reporting Items for Systematic reviews and Meta-Analyses guideline for systematic reviews was used, and relevant literature databases were searched. Primary outcomes were organ utilization rate and patient and graft survival after 1 year. Secondary outcomes included delayed graft function, primary nonfunction, serum creatinine, and biliary complications.

RESULTS

A total of 24 articles were included in this review. The technique is unanimously reported to be feasible and safe, but the available studies are characterized by considerable heterogeneity and bias.

CONCLUSIONS

Uniform reported outcome measures are needed to draw more definitive conclusions on transplant outcomes and organ utilization. A randomized controlled trial comparing aNRP with standard procurement technique in donation after circulatory death donors would be needed to show the added value of the procedure and determine its place among modern preservation techniques.

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.

Kidney Transplant From Uncontrolled Donation After Circulatory Death: Contribution of Normothermic Regional Perfusion

BACKGROUND

The French uncontrolled donors after circulatory death (DCD) protocol restricts donor age to <55 years, no-flow time to <30 minutes, and functional warm ischemia time to <150 minutes. In situ kidney perfusion can be performed at either 4°C (in situ cooling [ISC]) or 33-36°C (normothermic regional perfusion [NRP]). Hypothermic machine perfusion is systematically used. Only nonimmunized first transplant recipients were eligible. To improve the management of uncontrolled DCD, we tried to identify factors predictive of outcome.

METHODS

We identified all kidney transplants from uncontrolled DCD between 2007 and 2014 from the French Transplant Registry. Risk factors for primary nonfunction (PNF; n = 37) and poor renal function (estimated glomerular filtration rate < 30 mL/min or graft loss at 1 y, n = 66) were analyzed by using a multivariate logistic model.

RESULTS

This study analyzed 499 kidney transplantations, 50% of which were performed with NRP. Mean functional warm ischemia time was 135 minutes. Mean cold ischemia time was 14 hours. The principal PNF risk factor was young donor age (odds ratio [OR] = 0.95; P = 0.002). A sensitivity analysis showed a higher risk of PNF with ISC than with NRP (OR = 4.5; P = 0.015). Risk factors for poor renal function were donor body mass index (OR = 1.2; P < 0.001) and ISC versus NRP. Univariate analysis of uncontrolled DCD-specific risk factors showed no-flow time, functional warm time, and cold ischemia time did not affect the risk of PNF or poor renal function.

CONCLUSIONS

Uncontrolled DCD kidneys are an additional source of valuable transplants. NRP appears to decrease graft failure by restoring oxygenated blood as the first step of preconditioning.

Uncontrolled Donation After Circulatory Death: A Unique Opportunity

Uncontrolled donation after circulatory death (uDCD) refers to donation from persons who die following an unexpected and unsuccessfully resuscitated cardiac arrest. Despite the large potential for uDCD, programs of this kind only exist in a reduced number of countries with a limited activity. Barriers to uDCD are of a logistical and ethical-legal nature, as well as arising from the lack of confidence in the results of transplants from uDCD donors. The procedure needs to be designed to reduce and limit the impact of the prolonged warm ischemia inherent to the uDCD process, and to deal with the ethical issues that this practice poses: termination of advanced cardiopulmonary resuscitation, extension of advanced cardiopulmonary resuscitation beyond futility for organ preservation, moment to approach families to discuss donation opportunities, criteria for the determination of death, or the use of normothermic regional perfusion for the in situ preservation of organs. Although the incidence of primary nonfunction and delayed graft function is higher with organs obtained from uDCD donors, overall patient and graft survival is acceptable in kidney, liver, and lung transplantation, with a proper selection and management of both donors and recipients. Normothermic regional perfusion has shown to be critical to achieve optimal outcomes in uDCD kidney and liver transplantation. However, the role of ex situ preservation with machine perfusion is still to be elucidated. uDCD is a unique opportunity to improve patient access to transplantation therapies and to offer more patients the chance to donate organs after death, if this is consistent with their wishes and values.

Liver graft from donation after circulatory death donor: Real practice to improve graft viability

Donation after circulatory death (DCD) is an increasing source of liver grafts for transplantation, yet outcomes have been inferior compared to donation after brain death liver transplantation. These worse outcomes are mainly due to the severe graft injury resulting from mandatory warm ischemia during DCD organ recovery. New evidence, however, indicates that improved donor selection and surgical techniques can decrease the risk of graft failure and ischemic cholangiopathy (IC). Under current best practices, DCD organs are retrieved with the super-rapid technique, optimizing timing and protecting the liver graft from detrimental warm ischemia. Graft viability is influenced by both the quantity and quality of warm ischemia, which is unique to each donor and causes various degrees of pathophysiologic consequences. Evidence also shows that the choice of preservation solution and premortem heparin administration influences graft viability. Additionally, although the precise mechanism of IC remains unknown, stasis of blood during donor warm ischemia may cause the formation of microthrombi in the peribiliary vascular plexus and ischemia of the bile duct. Importantly, thrombolytic protocols show a possible preventive modality for IC. Finally, while ex vivo machine perfusion technology has gained an interest in DCD liver transplantation, further studies are necessary to evaluate the effectiveness of this evolving field to improve graft quality and transplant outcomes.

Liver Transplantation Using Uncontrolled Donors After Circulatory Death: A 10-year Single-center Experience

BACKGROUND

One method for increasing the donor pool for orthotopic liver transplantations (OLTs) is to use uncontrolled donation after circulation death (uDCDs).

METHODS

From January 2006 to December 2016, we performed 75 OLTs using uDCD livers. The control group comprised a sample of 265 OLTs using livers of donations after brain death (DBDs). A comparative study was performed.

RESULTS

Of 256 potential uDCD donors cannulated, 75 (29.3%) livers were accepted for OLT. The amount of hemoderivatives transfused was significantly higher in the uDCD group. The rate of primary nonfunction was also significantly higher (P = 0.031) in uDCD recipients (8%) than DBD recipients (1.5%). The overall rate of biliary complications was significantly higher (P = 0.001) in uDCD recipients (23 cases, 30.6%) than DBD recipients (28 cases, 10.6%). In the uDCD group, 1-, 3-, and 5-year patient survival rates were 82.7%, 73%, and 71.5%, respectively; in the DBD group, they were 89%, 83.7%, and 78.8%, respectively (P = 0.180). In the uDCD group, 1-, 3-, and 5-year graft survival rates were 73.3%, 65.1%, and 63.6%, respectively; in the DBD group, they were 87.1%, 81.9%, and 76.5%, respectively (P = 0.013). Multivariate analysis showed that independent risk factors for patient and graft survival were intraoperative transfusion of >6 units of packed red blood cell concentrates and recipients who were older than 60 years.

CONCLUSIONS

Although graft survival is significantly lower using uDCD livers, 5-year patient survival in recipients of DBD and uDCD livers is similar. After careful selection, the livers of uDCD can be selectively used for OLT.

Donation after circulatory death liver transplantation: consensus statements from the Spanish Liver Transplantation Society

Livers from donation after circulatory death (DCD) donors are an increasingly more common source of organs for transplantation. While there are few high-level studies in the field of DCD liver transplantation, clinical practice has undergone progressive changes during the past decade, in particular due to mounting use of postmortem normothermic regional perfusion (NRP). In Spain, uncontrolled DCD has been performed since the late 1980s/early 1990s, while controlled DCD was implemented nationally in 2012. Since 2012, the rise in DCD liver transplant activity in Spain has been considerable, and the great majority of DCD livers transplanted in Spain today are recovered with NRP. A panel of the Spanish Liver Transplantation Society was convened in 2018 to evaluate current evidence and accumulated experience in DCD liver transplantation, in particular addressing issues related to DCD liver evaluation, acceptance criteria, and recovery as well as recipient selection and postoperative management. This panel has created a series of consensus statements for the standard of practice in Spain and has published these statements with the hope they might help guide other groups interested in implementing new forms of DCD liver transplantation and/or introducing NRP into their clinical practices.

Donation after circulatory death liver transplantation: What are the limits for an acceptable DCD graft?

The utilization of donation after circulatory death (DCD) livers has been growing over the last decade. In large-volume centers, survival outcomes have improved and are comparable to outcomes with brain death donor (DBD) liver transplantation (LT). The relatively concentrated success with DCD LT demonstrated by high-volume transplant centers has rekindled international enthusiasm. The combination of increasing expertise in DCD LT and ongoing shortage in transplantable organs has promoted expansion of the DCD donor pool with regards to donor age, body mass index and donor warm ischemia time. In this review, we focused on the practice patterns in DCD liver graft utilization in the last decade, along with the possibilities for further expansion of DCD liver graft utilization and new technologies, such as machine perfusion.

Eight Years of Extracorporeal Membrane Oxygenation in Liver Transplantation: Our Experience

Liver grafts from donors after cardiac death (DCD) involve a risk of failure owing to warm ischemia, among other factors. To minimize this important issue, new systems like normothermic regional perfusion have arisen. We report an observational and unicentric study focused on the results of liver transplantation after DCD, performing normothermic regional perfusion using extracorporeal membrane oxygenation. In the period between 2011 and 2018, 33 recipients underwent the procedure, 9 from Maastricht II DCD donor liver transplantation (LT) and 24 from Maastricht III DCD donors. The median recipient survival rose to 67 ± 9 months and 41 ± 7 months, respectively. Only 1 patient suffered from ischemic cholangiopathy needing retransplantation. Therefore, according to our experience, liver grafts from DCD using extracorporeal membrane oxygenation are suitable for LT.

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.

Biliary Complications After Liver Transplantation From Uncontrolled Donors After Circulatory Death: Incidence, Management, and Outcome

The utilization of livers from donation after uncontrolled circulatory death (uDCD) increases the availability of liver grafts, but it is associated with a higher incidence of biliary complications (BCs) and lower graft survival than those organs donated after brain death. From January 2006 to December 2016, we performed 75 orthotopic liver transplantations (OLTs) using uDCD livers. To investigate the relationship of BCs with the use of uDCD OLT, we compared patients who developed BCs (23 patients) with those who did not (non-BC group, 43 patients) after excluding cases of hepatic artery thrombosis (a known cause of BC) and primary nonfunction. The groups had similar uDCD donor maintenance, donor and recipient characteristics, and perioperative morbidity/mortality rates, but we observed a higher rate of hepatocellular carcinoma and hepatitis C virus in the non-BC group. Percutaneous transhepatic biliary dilation, endoscopic retrograde cholangiopancreatography dilation, Roux-en-Y hepaticojejunostomy (HJ), a T-tube, and retransplantation were used for BC management. In the BC group, 1-, 3-, and 5-year patient survival rates were 91.3%, 69.6%, and 65.2%, respectively, versus 77.8%, 72.9%, and 72.9%, respectively, in the non-BC group (P = 0.89). However, 1-, 3-, and 5-year graft survival rates were 78.3%, 60.9%, and 56.5%, respectively, in the BC group versus 77.8%, 72.9%, and 72.9%, respectively, in the non-BC group (P = 0.38). Multivariate analysis did not indicate independent risk factors for BC development. In conclusion, patient and graft survival rates were generally lower in patients who developed BCs but not significantly so. These complications were managed in the majority of patients through radiological dilation, endoscopic dilation, or Roux-en-Y HJ. Retransplantation is necessary in rare cases after the failure of biliary dilation or surgical procedures.

Favorable Outcomes After Liver Transplantation With Normothermic Regional Perfusion From Donors After Circulatory Death: A Single-center Experience

BACKGROUND

Controlled donation after circulatory death (cDCD) has been associated with a high incidence of ischemic cholangiopathy and other perioperative complications. In an attempt to avoid these complications, we implemented an active protocol of cDCD liver transplant (LT) with normothermic regional perfusion (NRP) preservation.

METHODS

This is a descriptive analysis of data collected from a prospective date base of cDCD LT preserved with NRP from January 2015 to June 2017 with a minimum follow up of 9 months.

RESULTS

Fifty-seven potential cDCD donors were connected to the NRP system. Of these, 46 livers were transplanted over a 30-month period (80% liver recovery rate). The median posttransplant peak in alanine transaminase was 1136 U/L (220-6683 U/L). Seven (15%) patients presented postreperfusion syndrome and 11 (23%) showed early allograft dysfunction. No cases of ischemic cholangiopathy were diagnosed, and no graft loss was observed over a medium follow-up period of 19 months. Of note, 13 donors were older than 65 years, achieving comparable perioperative and midterm results to younger donors.

CONCLUSIONS

As far as we know, this represents the largest published series of cDCD LT with NRP preservation. Our results demonstrate that cDCD liver grafts preserved with NRP appear far superior to those obtained by the conventional rapid recovery technique.

Donors After Circulatory Death: Theme of Present or a Future? The Research in West Poland

The most urgent issue in transplantology nowadays is to increase the number of donors as replacement of lungs, heart, and liver in end-stage disease remains the only available method to save patients. Donors after brain death (DBD), these after irreversible cessation of brain function, represent 95% of all donors. On the contrary, donors after circulatory death (DCD), namely donors after irreversible detention of circulation, a group of great potential, is totally unused. The survey was done among 500 people from the medical staff of the intensive care unit and intensive cardiological care where the probability of receiving anonymous donation after circulatory death is the highest, yet only 368 people had completed the survey and their cases were taken into consideration as far as the study was concerned. The survey was conducted in the form of a self-projected questionnaire based on the Hospital Attitude Survey. The study showed that 98.4% of respondents accept the transplant. As many as 93.1% of people did not know the Maastricht classification, and 57.5% claimed that in Poland there is permission to take organs from people with a nonbeating heart. Ninety percent of respondents expressed their willingness to participate in training, and 70% of them were interested in the subject of the training presented in the questionnaire. At a time of such immense need for organs and such a huge disparity in the number of donors and recipients, DCD type of transplantation may be an alternative for patients whose waiting time for donation from a DBD would total a few years.

In Situ Normothermic Regional Perfusion for Liver Donation From China Category III (Organ Donation After Brain Death Followed by Circulatory Death): A Single-Center Cohort Study

OBJECTIVES

Organ donation after brain death followed by circulatory death is practiced in China. This study evaluated the application of normothermic regional perfusion to protect the liver grafts from these donors from warm ischemia in a large transplant center in China.

MATERIALS AND METHODS

This prospective study involved 19 liver transplants from brain death followed by circulatory death donors that were conducted between December 2014 and June 2017. We evaluated the baseline characteristics of the donors and recipients and compared outcomes of both groups. Graft and recipient survival and postoperative complications were also analyzed.

RESULTS

Although the normothermic regional perfusion group consisted of marginal donors with prolonged warm ischemia and recipients with higher Model for End-Stage Liver Disease scores (P < .05), postoperative tests indicated no differences in liverfunction recovery in both groups. Furthermore, total bilirubin decreased significantly faster in the normothermic regional perfusion group than in the control group (P < .05). Both groups showed similar 1-year recipient survival rates. No recipients in the normothermic regional perfusion group had any biliary complications, whereas 2 recipients in the control group developed ischemic cholangiopathy and received invasive treatment during follow-up.

CONCLUSIONS

In situ normothermic regional perfusion demonstrated a significant benefit in grafts from brain death followed by circulatory death donors and could potentially increase both the number and quality of donated organs.

Criteria to Identify a Potential Deceased Organ Donor: A Systematic Review

OBJECTIVES

To systematically review the global published literature defining a potential deceased organ donor and identifying clinical triggers for deceased organ donation identification and referral.

DATA SOURCES

Medline and Embase databases from January 2006 to September 2017.

STUDY SELECTION

All published studies containing a definition of a potential deceased organ donor and/or clinical triggers for referring a potential deceased organ donor were eligible for inclusion. Dual, independent screening was conducted of 3,857 citations.

DATA EXTRACTION

Data extraction was completed by one team member and verified by a second team member. Thematic content analysis was used to identify clinical criteria for potential deceased organ donation identification from the published definitions and clinical triggers.

DATA SYNTHESIS

One hundred twenty-four articles were included in the review. Criteria fell into four categories: Neurological, Medical Decision, Cardiorespiratory, and Administrative. Distinct and globally consistent sets of clinical criteria by type of deceased organ donation (neurologic death determination, controlled donation after circulatory determination of death, and uncontrolled donation after circulatory determination of death) are reported.

CONCLUSIONS

Use of the clinical criteria sets reported will reduce ambiguity associated with the deceased organ donor identification and the subsequent referral process, potentially reducing the number of missed donors and saving lives globally through increased transplantation.

Normothermic perfusion and outcomes after liver transplantation

Ischemia has been a persistent and largely unavoidable element in solid organ transplantation, contributing to graft deterioration and adverse post-transplant outcomes. In liver transplantation, where available organs arise with greater frequency from marginal donors (i.e., ones that are older, obese, and/or declared dead following cardiac arrest through the donation after circulatory death process), there is increasing interest using dynamic perfusion strategies to limit, assess, and even reverse the adverse effects of ischemia in these grafts. Normothermic perfusion, in particular, is used to restore the flow of oxygen and other metabolic substrates at physiological temperatures. It may be used in liver transplantation both in situ following cardiac arrest in donation after circulatory death donors or during part or all of the ex situ preservation phase. This review article addresses issues relevant to use of normothermic perfusion strategies in liver transplantation, including technical and logistical aspects associated with establishing and maintaining normothermic perfusion in its different forms and clinical outcomes that have been reported to date.

Normothermic regional perfusion vs. super-rapid recovery in controlled donation after circulatory death liver transplantation

BACKGROUND & AIMS

Although there is increasing interest in its use, definitive evidence demonstrating a benefit for postmortem normothermic regional perfusion (NRP) in controlled donation after circulatory death (cDCD) liver transplantation is lacking. The aim of this study was to compare results of cDCD liver transplants performed with postmortem NRP vs. super-rapid recovery (SRR), the current standard for cDCD.

METHODS

This was an observational cohort study including all cDCD liver transplants performed in Spain between June 2012 and December 2016, with follow-up ending in December 2017. Each donor hospital determined whether organ recovery was performed using NRP or SRR. The propensity scores technique based on the inverse probability of treatment weighting (IPTW) was used to balance covariates across study groups; logistic and Cox regression models were used for binary and time-to-event outcomes.

RESULTS

During the study period, there were 95 cDCD liver transplants performed with postmortem NRP and 117 with SRR. The median donor age was 56 years (interquartile range 45-65 years). After IPTW analysis, baseline covariates were balanced, with all absolute standardised differences <0.15. IPTW-adjusted risks were significantly improved among NRP livers for overall biliary complications (odds ratio 0.14; 95% CI 0.06-0.35, p <0.001), ischaemic type biliary lesions (odds ratio 0.11; 95% CI 0.02-0.57; p = 0.008), and graft loss (hazard ratio 0.39; 95% CI 0.20-0.78; p = 0.008).

CONCLUSIONS

The use of postmortem NRP in cDCD liver transplantation appears to reduce postoperative biliary complications, ischaemic type biliary lesions and graft loss, and allows for the transplantation of livers even from cDCD donors of advanced age.

LAY SUMMARY

This is a propensity-matched nationwide observational cohort study performed using livers recovered from donors undergoing cardiac arrest provoked by the intentional withdrawal of life support (controlled donation after circulatory death, cDCD). Approximately half of the livers were recovered after a period of postmortem in situ normothermic regional perfusion, which restored warm oxygenated blood to the abdominal organs, whereas the remainder were recovered after rapid preservation with a cold solution. The study results suggest that the use of postmortem normothermic regional perfusion helps reduce rates of post-transplant biliary complications and graft loss and allows for the successful transplantation of livers from older cDCD donors.

Excellent long-term outcome with lungs obtained from uncontrolled donation after circulatory death

We aimed to propose a simple and effective preservation method in lungs procured for transplantation from uncontrolled donation after circulatory death (uDCD) associated with excellent long-term results. Outcome measures for lung recipients were survival and primary graft dysfunction (PGD) grade 3. Survival was estimated using the Kaplan-Meier method. A total of 9 lung uDCDs were evaluated and 8 lung transplants were performed. Mean no-flow time was 9.8 minutes (standard deviation [SD] 8.6). Mean time from cardiac arrest to topical cooling was 96.8 minutes (SD 16.8). Preservation time was 159 minutes (SD 31). Ex vivo lung perfusion was used to assess lung function prior to transplantation in 2 cases. Mean recipient age was 60.8 years (SD 3.1), and mean total ischemic time was 678 minutes (SD 132). PGD grade 3 was observed in 2 cases (25%). The 1-month, 1-year, and 5-year survival rates were 100%, 87.5%, and 87.5%, respectively. Mean follow-up was 52 months. The logistic complexity of procuring lungs from uDCDs for transplantation requires the development of new strategies designed to facilitate this type of donation. A program based on strict selection criteria, using a simple and effective preservation technique, may recover lung grafts with excellent long-term posttransplant outcomes.

The efficacy of extracorporeal membrane oxygenation in liver transplantation from non-heart-beating donors: A systemic review and meta-analysis

BACKGROUND

A systematic review and meta-analysis was made to see whether extracorporeal membrane oxygenation (ECMO) in liver transplantation could improve non-heart-beating donors (NHBDs) recipients' outcomes compared with donors after brain death (DBDs) recipients.

METHODS

We searched MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials for eligible studies. The study eligible criteria are cohort or case-control studies using ECMO in all NHBDs; studies involved a comparison group of DBDs; and studies evaluated 1-year graft and patient survival rate in NHBDs and DBDs groups.

RESULTS

Four studies with 704 patients fulfilled the inclusion criteria. The pooled odds ratio (OR) of 1-year patient survival rate in NHBDs recipients compared with DBDs recipients was 0.8 (95% confidence interval [CI], 0.41-1.55). The pooled OR of 1-year graft survival rate in NHBDs recipients compared with DBDs recipients was 0.46 (95% CI, 0.26-0.81). NHBDs recipients were at greater risks to the occurrence of primary nonfunction (PNF) (OR = 7.12, 95% CI, 1.84-27.52) and ischemic cholangiopathy (IC) (OR = 9.46, 95% CI, 2.76-32.4) than DBDs recipients.

CONCLUSIONS

ECMO makes 1-year patient survival acceptable in NHBDs recipients. One-year graft survival rate was lower in NHBDs recipients than in DBDs recipients. Compared with DBDs recipients, the risks to develop PNF and IC were increased among NHBDs recipients.