Donation After Circulatory Death Liver Transplantation Research Articles

Retrieval Practice or Overall Donor and Recipient Risk: What Impacts on Outcomes After Donation After Circulatory Death Liver Transplantation in the United Kingdom?

Parameters of retrieval surgery are meticulously documented in the United Kingdom, where up to 40% of livers are donation after circulatory death (DCD) donations. This retrospective analysis focuses on outcomes after transplantation of DCD livers, retrieved by different UK centers between 2011 and 2016. Donor and recipient risk factors and the donor retrieval technique were assessed. A total of 236 DCD livers from 9 retrieval centers with a median UK DCD risk score of 5 (low risk) to 7 points (high risk) were compared. The majority used University of Wisconsin solution for aortic flush with a median hepatectomy time of 27-44minutes. The overall liver injury rate appeared relatively high (27.1%) with an observed tendency toward more retrieval injuries from centers performing a quicker hepatectomy. Among all included risk factors, the UK DCD risk score remained the best predictor for overall graft loss in the multivariate analysis (P<0.001). In high-risk and futile donor-recipient combinations, the occurrence of liver retrieval injuries had negative impact on graft survival (P=0.023). Expectedly, more ischemic cholangiopathies (P=0.003) were found in livers transplanted with a higher cumulative donor-recipient risk. Although more biliary complications with subsequent graft loss were found in high-risk donor-recipient combinations, the impact of the standardized national retrieval practice on outcomes after DCD liver transplantation was minimal.

Study protocol for a multicenter randomized controlled trial to compare the efficacy of end-ischemic dual hypothermic oxygenated machine perfusion with static cold storage in preventing non-anastomotic biliary strictures after transplantation of liver grafts donated after circulatory death: DHOPE-DCD trial

BackgroundThe major concern in liver transplantation of grafts from donation after circulatory death (DCD) donors remains the high incidence of non-anastomotic biliary strictures (NAS). Machine perfusion has been proposed as an alternative strategy for organ preservation which reduces ischemia-reperfusion injury (IRI). Experimental studies have shown that dual hypothermic oxygenated machine perfusion (DHOPE) is associated with less IRI, improved hepatocellular function, and better preserved mitochondrial and endothelial function compared to conventional static cold storage (SCS). Moreover, DHOPE was safely applied with promising results in a recently performed phase-1 study. The aim of the current study is to determine the efficacy of DHOPE in reducing the incidence of NAS after DCD liver transplantation.MethodsThis is an international multicenter randomized controlled trial. Adult patients (≥18 yrs. old) undergoing transplantation of a DCD donor liver (Maastricht category III) will be randomized between the intervention and control group. In the intervention group, livers will be subjected to two hours of end-ischemic DHOPE after SCS and before implantation. In the control group, livers will be subjected to care as usual with conventional SCS only. Primary outcome is the incidence of symptomatic NAS diagnosed by a blinded adjudication committee. In all patients, magnetic resonance cholangiography will be obtained at six months after transplantation.DiscussionDHOPE is associated with reduced IRI of the bile ducts. Whether reduced IRI of the bile ducts leads to lower incidence of NAS after DCD liver transplantation can only be examined in a randomized controlled trial.Trial registrationThe trial was registered in Clinicaltrials.gov in September 2015 with the identifier NCT02584283.

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

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. 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. 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). 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. 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.

Outcomes of DCD liver transplantation using organs treated by hypothermic oxygenated perfusion before implantation

Donation after circulatory death (DCD) liver transplantation is known for potentially worse outcomes because of higher rates of graft non-function or irreversible cholangiopathy. The impact of machine liver perfusion techniques on these complications remains elusive. We aimed to provide data on 5-year outcomes in patients receiving DCD liver transplants, after donor organs had been treated by hypothermic oxygenated perfusion (HOPE). Fifty HOPE-treated DCD liver transplants performed in Zurich between 2012 and 3/2017 were matched with 50 primary donation after brain death (DBD) liver transplants, and with 50 untreated DCD liver transplants in Birmingham. Match factors focussed on short cold ischaemia, comparable recipient age and low recipient laboratory model for end-stage liver disease scores. Primary endpoints were post-transplant complications, and non-tumour-related patient death or graft loss. Despite extended donor warm ischaemia, HOPE-treated DCD liver transplants achieved similar overall graft survival, compared to standard DBD liver transplants. Particularly, graft loss due to any non-tumour-related causes occurred in 8% (4/50) of cases. In contrast, untreated DCD livers resulted in non-tumour-related graft failure in one-third (16/50) of cases (p = 0.005), despite significantly (p <0.001) shorter functional donor warm ischaemia. Five-year graft survival, censored for tumour death, was 94% for HOPE-treated DCD liver transplants vs. 78% in untreated DCD liver transplants (p = 0.024). The 5-year outcomes of HOPE-treated DCD liver transplants were similar to those of DBD primary transplants and superior to those of untreated DCD liver transplants, despite much higher risk. These results suggest that a simple end-ischaemic perfusion approach is very effective and may open the field for safe utilisation of extended DCD liver grafts. Machine perfusion techniques are currently being introduced into the clinic, with the aim of optimising injured grafts prior to implantation. While short-term effects of machine liver perfusion have been frequently reported in terms of hepatocellular enzyme release and early graft function, the long-term benefit on irreversible graft loss has been unclear. Herein, we report on 5-year graft survival in donation after cardiac death livers, treated either by conventional cold storage, or by 1-2 h of hypothermic oxygenated perfusion (HOPE) after cold storage. Graft loss was significantly less in HOPE-treated livers, despite longer donor warm ischaemia times. Therefore, HOPE after cold storage appears to be a simple and effective method to treat high-risk livers before implantation.

Onset of Donor Warm Ischemia Time in Donation After Circulatory Death Liver Transplantation: Hypotension or Hypoxia?

The aim of this study was to investigate the impact of hypoxia and hypotension during the agonal phase of donor warm ischemia time (DWIT) on hepatic ischemia/reperfusion injury (IRI) and complications in donation after circulatory death (DCD) liver transplantation. A retrospective single‐center study of 93 DCD liver transplants (Maastricht type III) was performed. DWIT was divided into 2 periods: the agonal phase (from withdrawal of treatment [WoT] until circulatory arrest) and the asystolic phase (circulatory arrest until cold perfusion). A drop to <80% in peripheral oxygenation (SpO2) was considered as hypoxia in the agonal phase (SpO2‐agonal) and a drop to <50 mm Hg as hypotension in the agonal phase (SBP‐agonal). Peak postoperative aspartate transaminase level >3000 U/L was considered as severe hepatic IRI. SpO2 dropped within 2 minutes after WoT <80%, whereas the systolic blood pressure dropped to <50 mm Hg after 9 minutes, resulting in a longer SpO2‐agonal (13 minutes) than SBP‐agonal (6 minutes). In multiple logistic regression analysis, only duration of SpO2‐agonal was associated with severe hepatic IRI (P = 0.006) and not SBP‐agonal (P = 0.32). Also, recipients with long SpO2‐agonal (>13 minutes) had more complications with a higher Comprehensive Complication Index during hospital admission (43.0 versus 32.0; P = 0.002) and 90‐day graft loss (26% versus 6%; P = 0.01), compared with recipients with a short SpO2‐agonal (≤13 minutes). Furthermore, Cox proportional hazard modeling identified a long SpO2‐agonal as a risk factor for longterm graft loss (hazard ratio, 3.30; 95% confidence interval, 1.15‐9.48; P = 0.03). In conclusion, the onset of hypoxia during the agonal phase is related to the severity of hepatic IRI and postoperative complications. Therefore, SpO2 <80% should be considered as the start of functional DWIT in DCD liver transplantation.

Better Graft Survival with no Ischemic Cholangiopathy in DCD Liver Transplantation in the UK using Normothermic Regional Perfusion (NRP)

Background Normothermic regional perfusion, whereby the donor is placed on an extracorporeal circuit to circulate oxygenated blood to the abdominal viscera after death, is increasingly being used in controlled donation after circulatory death (DCD) donation. We evaluated the joint experience of the two centres pioneering this technique in the UK and compared NRP DCD liver transplants to non-NRP DCD livers transplanted at each centre in the same period. Methods Between 1/1/2011 and 31/5/17, 44 patients underwent liver transplantation following NRP; these were compared to 185 DCD liver transplants without NRP performed in the same period. NRP was performed for a median 123 (IQR 101-130) minutes before in-situ cold perfusion. Results Table 1 summarises the results. There was no significant difference in the recipient age (58 vs 61) or UK End Stage Liver disease (UKELD) score (55.7 NRP vs 54.3 non-NRP) between groups. 90 day patient survival was similar (100% NRP vs 96.7% non-NRP). There was a significant reduction in ischemic cholangiopathy and early allograft dysfunction with a better graft survival at 90 days. Conclusion Livers from DCD donors undergoing NRP have a lower incidence of primary non function and early allograft dysfunction, fewer biliary complications, and significantly better early graft survival.

“Super-rapid” Technique in Donation After Circulatory Death Liver Donors: Advantages and Disadvantages

In recent years, donation after circulatory death (DCD) has increased as an option to overcome the organ donor shortage crisis and to decrease the large number of patients on liver transplant waiting lists. The “super-rapid” technique is now the “gold standard” procurement method because of its availability, reproducibility, low cost, and extensive experience. Recently, extracorporeal support has been implemented, with encouraging results. Strict donor acceptance criteria have proven to be essential to optimize the DCD liver graft outcomes and minimize biliary complication rates. In this study we assessed the state of the art of DCD liver transplantation with regard to its development and the actual strategies to prevent graft complications, with aim of expanding the pool of marginal liver donors.

The Impact of Combined Warm Ischemia Time on Development of Acute Kidney Injury in Donation After Circulatory Death Liver Transplantation: Stay Within the Golden Hour.

Acute kidney injury (AKI) is a common complication after liver transplantation and more frequently observed when high-risk grafts, such as donation after circulatory death (DCD) grafts are used. Our aim was to investigate the impact of the ischemia periods on development of AKI in DCD liver transplantation. We performed a 2-center retrospective study with 368 DCD graft-recipients. Donor warm ischemia time (DWIT) was divided into agonal phase (withdrawal of life support-cardiac arrest) and asystolic phase (cardiac arrest-start cold perfusion). We introduced a new period of warm ischemia: the combined warm ischemia time (combined WIT), which was defined as the sum of DWIT and recipient WIT. AKI was observed in 65% of the recipients and severe AKI in 41% (KDIGO stage 2/3). The length of combined WIT increased significantly with AKI severity: 61 minutes in recipients without AKI up to 69 minutes in recipients with the most severe form of AKI (P < 0.001). On multivariable analysis, increasing duration of the combined WIT was associated with an increased risk of developing severe AKI (odds ratio, 1.032 per every extra minute; 95% confidence interval, 1.014-1.051; P < 0.001). No relation was observed between length of cold ischemia time and severe AKI. Combined WIT is a newly defined period of warm ischemia in DCD liver transplantation. Length of combined WIT is associated with severity of postoperative AKI and should ideally not exceed 60 minutes.

DCD Liver Transplant: a Meta-review of the Evidence and Current Optimization Strategies

In the current era of liver transplantation (LT), there is a large discrepancy between waiting list demand and organ donor availability. Increased utilization of donation after circulatory death (DCD) donors continues to expand the donor pool and improve access; however, concerns regarding recipient outcomes have limited wider adoption of these donor livers. This review will describe the current evidence regarding recipient outcomes and strategies that may help to optimize them. Historical outcomes of DCD LT are somewhat inferior to the DBD LT, yet new emerging evidence suggests that this outcome disparity may only be marginal at most; however, ischemic cholangiopathy remains a concern. Ideal donor selection criteria and optimizing recipient operative times appear to mitigate some of this risk. Extracorporeal membrane oxygenation (ECMO), hypothermic machine perfusion (HMP), and normothermic machine perfusion (NMP) are promising strategies to further improve graft resilience and performance. Cardiac death donors continue to expand the donor pool but may carry an increased risk of biliary complications. Graft reconditioning techniques, donor selection, and recipient optimization appear to mitigate this risk; however, these strategies need further investigation before generalized adoption.

A literature-based cost analysis of tissue plasminogen activator for prevention of biliary stricture in donation after circulatory death liver transplantation

IntroductionThis study sought to approximate the cost-effectiveness of tPA utilization for prevention of biliary strictures (PTBS) in donation after circulatory death liver transplantation (DCD-LT). MethodsPreviously-reported PTBS rates in DCD-LT with and without tPA were used to calculate the number needed to treat (NNT) for prevention of one PTBS. The incremental cost of PTBS was then used to determine the cost effectiveness of tPA for prevention of PTBS. ResultsThe incidence of PTBS in the setting of tPA administration was 20%, while incidence in patients without tPA use was 43% (p < 0.001). Meta-analysis demonstrated a risk reduction of 15.7%, which translated into a NNT of 6.4. Cost associated with treating 6.4 patients was $50,353. Based on an incremental cost of $81,888 associated with PTBS management, use of tPA in DCD-LT protocols was estimated to save $31,528 per PTBS prevented. ConclusionUtilization of tPA in DCD-LT protocols represents one possible cost-effective strategy for prevention of PTBS in DCD-LT.

The UK DCD Risk Score: A new proposal to define futility in donation-after-circulatory-death liver transplantation

Primary non-function and ischaemic cholangiopathy are the most feared complications following donation-after-circulatory-death (DCD) liver transplantation. The aim of this study was to design a new score on risk assessment in liver-transplantation DCD based on donor-and-recipient parameters. Using the UK national DCD database, a risk analysis was performed in adult recipients of DCD liver grafts in the UK between 2000 and 2015 (n = 1,153). A new risk score was calculated (UK DCD Risk Score) on the basis of a regression analysis. This is validated using the United Network for Organ Sharing database (n = 1,617) and our own DCD liver-transplant database (n = 315). Finally, the new score was compared with two other available prediction systems: the DCD risk scores from the University of California, Los Angeles and King's College Hospital, London. The following seven strongest predictors of DCD graft survival were identified: functional donor warm ischaemia, cold ischaemia, recipient model for end-stage liver disease, recipient age, donor age, previous orthotopic liver transplantation, and donor body mass index. A combination of these risk factors (UK DCD risk model) stratified the best recipients in terms of graft survival in the entire UK DCD database, as well as in the United Network for Organ Sharing and in our own DCD population. Importantly, the UK DCD Risk Score significantly predicted graft loss caused by primary non-function or ischaemic cholangiopathy in the futile group (>10 score points). The new prediction model demonstrated a better C statistic of 0.79 compared to the two other available systems (0.71 and 0.64, respectively). The UK DCD Risk Score is a reliable tool to detect high-risk and futile combinations of donor-and-recipient factors in DCD liver transplantation. It is simple to use and offers a great potential for making better decisions on which DCD graft should be rejected or may benefit from functional assessment and further optimization by machine perfusion. In this study, we provide a new prediction model for graft loss in donation-after-circulatory-death (DCD) liver transplantation. Based on UK national data, the new UK DCD Risk Score involves the following seven clinically relevant risk factors: donor age, donor body mass index, functional donor warm ischaemia, cold storage, recipient age, recipient laboratory model for end-stage liver disease, and retransplantation. Three risk classes were defined: low risk (0-5 points), high risk (6-10 points), and futile (>10 points). This new model stratified best in terms of graft survival compared to other available models. Futile combinations (>10 points) achieved an only very limited 1- and 5-year graft survival of 37% and less than 20%, respectively. In contrast, an excellent graft survival has been shown in low-risk combinations (≤5 points). The new model is easy to calculate at the time of liver acceptance. It may help to decide which risk combination will benefit from additional graft treatment, or which DCD liver should be declined for a certain recipient.

Hepatitis C Virus Recurrence Occurs Earlier in Patients Receiving Donation After Circulatory Death Liver Transplant Grafts Compared With Those Receiving Donation After Brainstem Death Grafts

IntroductionHepatitis C virus (HCV)-related cirrhosis remains the commonest indication for liver transplantation worldwide, yet few studies have investigated the impact of donation after circulatory death (DCD) graft use on HCV recurrence and patient outcomes. DCD grafts have augmented the limited donor organ pool and reduced wait-list mortality, although concerns regarding graft longevity and patient outcome persist. MethodsThis was a single-center study of all HCV + adults who underwent DCD liver transplantation between 2004 and 2014. 44 HCV+ patients received DCD grafts, and were matched with 44 HCV+ recipients of donation after brainstem death (DBD) grafts, and their outcomes examined. ResultsThe groups were matched for age, sex, and presence of hepatocellular carcinoma; no significant differences were found between the group's donor or recipient characteristics. Paired and unpaired analysis demonstrated that HCV recurrence was more rapid in recipients of DCD organs compared with DBD grafts (408 vs 657 days; P = .006). There were no significant differences in graft survival, patient survival, or rates of biliary complications between the cohorts despite DCD donors being 10 years older on average than those used in other published experience. ConclusionsIn an era of highly effective direct acting antiviral therapy, rapid HCV recrudescence in grafts from DCD donors should not compromise long-term morbidity or mortality. In the context of rising wait-list mortality, it is prudent to use all available sources to expand the pool of donor organs, and our data support the practice of using extended-criteria DCD grafts based on donor age. Notwithstanding that, clinicians should be aware that HCV recrudescence is more rapid in DCD recipients, and early post-transplant anti-viral therapy is indicated to prevent graft injury.

Clinical outcomes of donation after circulatory death liver transplantation in primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a progressive fibro-inflammatory cholangiopathy for which liver transplantation is the only life-extending intervention. These patients may benefit from accepting liver donation after circulatory death (DCD), however their subsequent outcome is unknown. The aim of this study was to determine the clinical impact of using DCD liver grafts in patients specifically undergoing transplantation for PSC. Clinical outcomes were prospectively evaluated in PSC patients undergoing transplantation from 2006 to 2016 stratified by donor type (DCD, n=35 vs. donation after brainstem death [DBD], n=108). In liver transplantation for PSC; operating time, days requiring critical care support, total ventilator days, incidence of acute kidney injury, need for renal replacement therapy (RRT) or total days requiring RRT were not significantly different between DCD vs. DBD recipients. Although the incidence of ischaemic-type biliary lesions was greater in the DCD group (incidence rate [IR]: 4.4 vs. 0 cases/100-patient-years; p<0.001) there was no increased risk of post-transplant biliary strictures overall (hazard ratio [HR]: 1.20, 0.58-2.46; p=0.624), or in sub-analysis specific to anastomotic strictures or recurrent PSC, between donor types. Graft loss and mortality rates were not significantly different following transplantation with DCD vs. DBD livers (IR: 3.6 vs. 3.1 cases/100-patient-years, p=0.34; and 3.9 vs. 4.7, p=0.6; respectively). DCD liver transplantation in PSC did not impart a heightened risk of graft loss (HR: 1.69, 0.58-4.95, p=0.341) or patient mortality (0.75, 0.25-2.21, p=0.598). Transplantation with DCD (vs. DBD) livers in PSC patients does not impact graft loss or patient survival. In an era of organ shortage, DCD grafts represent a viable therapeutic option for liver transplantation in PSC patients. Lay summary: This study examines the impact of liver transplantation in primary sclerosing cholangitis (PSC) with organs donated after circulatory death (DCD), compared to donation after brainstem death (DBD). We show that in appropriately selected patients, the outcomes for DCD transplantation mirror those using DBD livers, with no significant differences in complication rate, patient survival or transplanted liver survival. In an era of organ shortage and increasing wait-list times, DCD livers represent a potential treatment option for transplantation in PSC.

An Oxygenated and Transportable Machine Perfusion System Fully Rescues Liver Grafts Exposed to Lethal Ischemic Damage in a Pig Model of DCD Liver Transplantation.

Control of warm ischemia (WI) lesions that occur with donation after circulatory death (DCD) would significantly increase the donor pool for liver transplantation. We aimed to determine whether a novel, oxygenated and hypothermic machine perfusion device (HMP Airdrive system) improves the quality of livers derived from DCDs using a large animal model. Cardiac arrest was induced in female large white pigs by intravenous injection of potassium chloride. After 60 minutes of WI, livers were flushed in situ with histidine-tryptophan-ketoglutarate and subsequently preserved either by simple cold storage (WI-SCS group) or HMP (WI-HMP group) using Belzer-MPS solution. Liver grafts procured from heart-beating donors and preserved by SCS served as controls. After 4 hours of preservation, all livers were transplanted. All recipients in WI-SCS group died within 6 hours after transplantation. In contrast, the HMP device fully protected the liver against lethal ischemia/reperfusion injury, allowing 100% survival rate. A postreperfusion syndrome was observed in all animals of the WI-SCS group but none of the control or WI-HMP groups. After reperfusion, HMP-preserved livers functioned better and showed less hepatocellular and endothelial cell injury, in agreement with better-preserved liver histology relative to WI-SCS group. In addition to improved energy metabolism, this protective effect was associated with an attenuation of inflammatory response, oxidative load, endoplasmic reticulum stress, mitochondrial damage, and apoptosis. This study demonstrates for the first time the efficacy of the HMP Airdrive system to protect liver grafts from lethal ischemic damage before transplantation in a clinically relevant DCD model.

Safety and Outcomes in 100 Consecutive Donation After Circulatory Death Liver Transplants Using a Protocol That Includes Thrombolytic Therapy.

Donation after circulatory death (DCD) liver transplantation (LT) reportedly yields inferior survival and increased complication rates compared with donation after brain death (DBD). We compare 100 consecutive DCD LT using a protocol that includes thrombolytic therapy (late DCD group) to an historical DCD group (early DCD group n = 38) and a cohort of DBD LT recipients (DBD group n = 435). Late DCD LT recipients had better 1- and 3-year graft survival rates than early DCD LT recipients (92% vs. 76.3%, p = 0.03 and 91.4% vs. 73.7%, p = 0.01). Late DCD graft survival rates were comparable to those of the DBD group (92% vs. 93.3%, p = 0.24 and 91.4% vs. 88.2%, p = 0.62). Re-transplantation occurred in 18.4% versus 1% for the early and late DCD groups, respectively (p = 0.001). Patient survival was similar in all three groups. Ischemic-type biliary lesions (ITBL) occurred in 5%, 3%, and 0.2% for early DCD, late DCD, and DBD groups, respectively, but unlike in the early DCD group, in the late DCD group ITBL was endoscopically managed and resolved in each case. Using a protocol that includes a thrombolytic therapy, DCD LT yielded patient and graft survival rates comparable to DBD LT.

Dual hypothermic oxygenated machine perfusion in liver transplants donated after circulatory death.

BackgroundExperimental studies have suggested that end‐ischaemic dual hypothermic oxygenated machine perfusion (DHOPE) may restore hepatocellular energy status and reduce reperfusion injury in donation after circulatory death (DCD) liver grafts. The aim of this prospective case–control study was to assess the safety and feasibility of DHOPE in DCD liver transplantation.MethodsIn consecutive DCD liver transplantations, liver grafts were treated with end‐ischaemic DHOPE. Outcome was compared with that in a control group of DCD liver transplantations without DHOPE, matched for donor age, donor warm ischaemia time, and recipient Model for End‐stage Liver Disease (MELD) score. All patients were followed for 1 year.ResultsTen transplantations involving liver grafts treated with DHOPE were compared with 20 control procedures. There were no technical problems. All 6‐month and 1‐year graft and patient survival rates were 100 per cent in the DHOPE group. Six‐month graft survival and 1‐year graft and patient survival rates in the control group were 80, 67 and 85 per cent respectively. During DHOPE, median (i.q.r.) hepatic adenosine 5′‐triphosphate (ATP) content increased 11‐fold, from 6 (3–10) to 66 (42–87) µmol per g protein (P = 0·005). All DHOPE‐preserved livers showed excellent early function. At 1 week after transplantation peak serum alanine aminotransferase (ALT) and bilirubin levels were twofold lower in the DHOPE group than in the control group (ALT: median 966 versus 1858 units/l respectively, P = 0·006; bilirubin: median 1·0 (i.q.r. 0·7–1·4) versus 2·6 (0·9–5·1) mg/dl, P = 0·044). None of the ten DHOPE‐preserved livers required retransplantation for non‐anastomotic biliary stricture, compared with five of 20 in the control group (P = 0·140).ConclusionThis clinical study of end‐ischaemic DHOPE in DCD liver transplantation suggests that the technique restores hepatic ATP, reduces reperfusion injury, and is safe and feasible. RCTs with larger numbers of patients are warranted to assess the efficacy in reducing post‐transplant biliary complications.

Pathophysiological Trends During Withdrawal of Life Support: Implications for Organ Donation After Circulatory Death.

Donation after circulatory death (DCD) provides an alternative pathway to deceased organ transplantation. Although clinical DCD lung, liver, and kidney transplantation are well established, transplantation of hearts retrieved from DCD donors has reached clinical translation only recently. Progress has been limited by concern regarding the viability of DCD hearts. The aim of this study was to document the pathophysiological changes that occur in the heart and circulation during withdrawal of life (WLS) support. In a porcine asphyxia model, we characterized the hemodynamic, volumetric, metabolic, biochemical, and endocrine changes after WLS for up to 40 minutes. Times to circulatory arrest and electrical asystole were recorded. After WLS, there was rapid onset of profound hypoxemia resulting in acute pulmonary hypertension and right ventricular distension. Concurrently, progressive systemic hypotension occurred with a fall in left atrial pressure and little change in left ventricular volume. Mean times to circulatory arrest and electrical asystole were 8 ± 1 and 16 ± 2 minutes, respectively. Hemodynamic changes were accompanied by a rapid fall in pH, and rise in blood lactate, troponin-T, and potassium. Plasma noradrenaline and adrenaline levels rose rapidly with dramatic increases in coronary sinus levels indicative of myocardial release. These findings provide insight into the nature and tempo of the damaging events that occur in the heart and in particular the right ventricle during WLS, and give an indication of the limited timeframe for the implementation of potential postmortem interventions that could be applied to improve organ viability.

Role of donor hemodynamic trajectory in determining graft survival in liver transplantation from donation after circulatory death donors

Donation after circulatory death (DCD) donors show heterogeneous hemodynamic trajectories following withdrawal of life support. Impact of hemodynamics in DCD liver transplant is unclear, and objective measures of graft viability would ease transplant surgeon decision making and inform safe expansion of the donor organ pool. This retrospective study tested whether hemodynamic trajectories were associated with transplant outcomes in DCD liver transplantation (n = 87). Using longitudinal clustering statistical techniques, we phenotyped DCD donors based on hemodynamic trajectory for both mean arterial pressure (MAP) and peripheral oxygen saturation (SpO2 ) following withdrawal of life support. Donors were categorized into 3 clusters: those who gradually decline after withdrawal of life support (cluster 1), those who maintain stable hemodynamics followed by rapid decline (cluster 2), and those who decline rapidly (cluster 3). Clustering outputs were used to compare characteristics and transplant outcomes. Cox proportional hazards modeling revealed hepatocellular carcinoma (hazard ratio [HR] = 2.53; P = 0.047), cold ischemia time (HR = 1.50 per hour; P = 0.027), and MAP cluster 1 were associated with increased risk of graft loss (HR = 3.13; P = 0.021), but not SpO2 cluster (P = 0.172) or donor warm ischemia time (DWIT; P = 0.154). Despite longer DWIT, MAP and SpO2 clusters 2 showed similar graft survival to MAP and SpO2 clusters 3, respectively. In conclusion, despite heterogeneity in hemodynamic trajectories, DCD donors can be categorized into 3 clinically meaningful subgroups that help predict graft prognosis. Further studies should confirm the utility of liver grafts from cluster 2. Liver Transplantation 22 1469-1481 2016 AASLD.

Donation After Circulatory Death for Liver Transplantation: A Meta-Analysis on the Location of Life Support Withdrawal Affecting Outcomes.

Liver transplantation using donation after circulatory death (DCD) donors is associated with inferior outcomes compared to donation after brain death (DBD). Prolonged donor warm ischemic time has been identified as the key factor responsible for this difference. Various aspects of the donor life support withdrawal procedure, including location of withdrawal and administration of antemortem heparin, are thought to play important roles in mitigating the effects of warm ischemia. However, a systematic exploration of these factors is important for more confident integration of these practices into a standard DCD protocol. Medline, EMBASE, and Cochrane libraries were systematically searched and 23 relevant studies identified for analysis. Donation after circulatory death recipients were stratified according to location of life support withdrawal (intensive care unit or operating theater) and use of antemortem heparin. Donation after circulatory death recipients had comparable 1-year patient survival to DBD recipients if the location of withdrawal of life support was the operating theater, but not if the location was the intensive care unit. Likewise, the inferior 1-year graft survival and higher incidence of ischemic cholangiopathy of DCD compared with DBD recipients were improved by withdrawal in operating theater, although higher rates of ischemic cholangiopathy and worse graft survival were still observed in DCD recipients. Furthermore, administering heparin before withdrawal of life support reduced the incidence of primary nonfunction of the allograft. Our evidence suggests that withdrawal in the operating theater and premortem heparin administration improve DCD liver transplant outcomes, thus allowing for the most effective usage of these valuable organs.

Optimization of Perioperative Conditions to Prevent Ischemic Cholangiopathy in Donation After Circulatory Death Donor Liver Transplantation.

Donation after circulatory death (DCD) donor pool remains underutilized for liver transplantation (LT). We describe optimizing "modifiable risk factors," such as cold ischemia time (CIT) recipient warm ischemia time (WIT) and the use of thrombolytic flush at the time of procurement to minimize ischemic cholangiopathy (IC). From July 2011 (era II), to improve outcomes after DCD LT, measures were taken to minimize CIT, operative time and recipient WIT along with the use of tissue plasminogen activator (tPA) flush during DCD procurements. Thirty consecutive DCD LTs were performed prospectively in era II. Outcomes were compared with 61 historic controls (era I). Reperfusion biopsies were evaluated for the presence of necrosis and biliary epithelial damage. Median CIT (4.9 [3.5-5.9] vs 6.4 [4.3-12]; P < 0.001), hepatectomy time (70 [42-120] vs 81 [58-207]; P = 0.02), and recipient WIT (16 [13-31] vs 24[15-40]; P < 0.001) were significantly shorter in era II. All patients in era II received tPA flushed liver grafts. None of the patients in era II developed IC (0% vs 18%; P = 0.013). There were fewer biliary complications in era II, and there was no increased risk of bleeding associated with the use of tPA. One-year graft survival was slightly better in era II (n = 24 patients with 1 year follow-up) (88% vs 80%; P = 0.14). Optimizing peritransplant conditions, such as shortening ischemic times with the use of thrombolytic donor flush, may prevent IC after DCD LT. With this approach, the DCD donor pool may be expanded.