Single-center experience with liver transplantation from controlled non-heartbeating donors: a viable source of grafts

Role of normothermic machine perfusion in liver transplantation: Current trends and outcomes

Background

Liver transplantation is the only known curative treatment option for end-stage liver diseases and failure; however, there is an imbalance between the number of available liver organs for transplant and the number of patients as recipients due to a shortage of suitable organs. In recent years, ex vivo liver machine perfusion has been introduced to liver transplantation to expand the donor organ pool. Studies showed that using normothermic machine perfusion can increase the pool of transplantable discarded livers and is a promising strategy to improve graft resilience and performance further.

Methods

A systematic literature search of PubMed and ClinicalTrials.gov registry was performed. A three-stage independent screening method was applied. Inclusion criteria for this review were published prospective, retrospective, clinical trials, and systematic reviews studies using normothermic machine perfusion devices.

Results

Twenty-two articles on normothermic liver machine perfusion with patients and graft survival rate were identified. These studies have demonstrated the safety and efficacy of normothermic liver machine perfusion for discarded liver preservation in both standard and expanded criteria donors following patients and graft follow-ups. The overall number of livers that went under NMP was 568 in all the studies in which 503 of the livers were transplanted (88.6%). The 30,90,180 days and 1-year patients and grafts survival rates were promising.

Conclusion

Normothermic machine perfusion is a novelty method recently being used in liver transplantation and can lead to the expansion of the liver donor pool by revitalizing discarded livers. Our study was able to show the promising outcomes for both patients and grafts, which were achieved in many human clinical studies around the world using normothermic machine perfusion as a method of liver preservation and revitalization.

National time trends in mortality and graft survival following liver transplantation from circulatory death or brainstem death donors

BACKGROUND

Despite high waiting list mortality rates, concern still exists on the appropriateness of using livers donated after circulatory death (DCD). We compared mortality and graft loss in recipients of livers donated after circulatory or brainstem death (DBD) across two successive time periods.

METHODS

Observational multinational data from the United Kingdom and Ireland were partitioned into two time periods (2008-2011 and 2012-2016). Cox regression methods were used to estimate hazard ratios (HRs) comparing the impact of periods on post-transplant mortality and graft failure.

RESULTS

A total of 1176 DCD recipients and 3749 DBD recipients were included. Three-year patient mortality rates decreased markedly from 19.6 per cent in time period 1 to 10.4 per cent in time period 2 (adjusted HR 0.43, 95 per cent c.i. 0.30 to 0.62; P < 0.001) for DCD recipients but only decreased from 12.8 to 11.3 per cent (adjusted HR 0.96, 95 per cent c.i. 0.78 to 1.19; P = 0.732) in DBD recipients (P for interaction = 0.001). No time period-specific improvements in 3-year graft failure were observed for DCD (adjusted HR 0.80, 95% c.i. 0.61 to 1.05; P = 0.116) or DBD recipients (adjusted HR 0.95, 95% c.i. 0.79 to 1.14; P = 0.607). A slight increase in retransplantation rates occurred between time period 1 and 2 in those who received a DCD liver (from 7.3 to 11.8 per cent; P = 0.042), but there was no change in those receiving a DBD liver (from 4.9 to 4.5 per cent; P = 0.365). In time period 2, no difference in mortality rates between those receiving a DCD liver and those receiving a DBD liver was observed (adjusted HR 0.78, 95% c.i. 0.56 to 1.09; P = 0.142).

CONCLUSION

Mortality rates more than halved in recipients of a DCD liver over a decade and eventually compared similarly to mortality rates in recipients of a DBD liver. Regions with high waiting list mortality may mitigate this by use of DCD livers.

Evolving utilization of donation after circulatory death livers in liver transplantation: The day of DCD has come

Compared to donation after brain death (DBD), livers procured for transplantation from donation after circulatory death (DCD) donors experience more ischemia-reperfusion injury and higher rates of ischemic cholangiopathy due to the period of warm ischemic time (WIT) following withdrawal of life support. As a result, utilization of DCD livers for liver transplant (LT) has generally been limited to short WITs and younger aged donor grafts, causing many recovered DCD organs to be discarded without consideration for transplant. This study assesses how DCD liver utilization and outcomes have changed over time, using OPTN data from adult, first-time, deceased donor, whole-organ LTs between January 1995 and December 2019. Results show that increased clinical experience with DCD LT has translated into increased use of livers from DCD donors, shorter ischemic times, shorter lengths of hospitalization after transplant, and lower rates of retransplantation. The data also reveal that over the past decade, the rate of increase in DCD LTs conducted in the United States has outpaced that of DBD. Together, these trends signal an opportunity for the field of liver transplantation to mitigate the organ shortage by capitalizing on DCD liver allografts that are currently not being utilized.

Effects of SP600125 and hypothermic machine perfusion on livers donated after cardiac death in a pig allograft transplantation model

BACKGROUND

Hypothermic machine perfusion (HMP) improves the quality of donor livers for transplantation, both in animal models and in clinical practice. Treatment with SP600125, an inhibitor of c-Jun N-terminal kinase (JNK), can suppress the JNK signaling pathway to alleviate donor liver ischemia-reperfusion injury (IRI). We performed the present study with the objective of exploring the protective effects exerted by a combination of HMP and SP600125 on liver xenograft viability for donation after cardiac death (DCD) in a porcine model.

METHODS

54 adult BAMA mini-pigs were randomly assigned to 5 groups, including sham, cold storage for 4 h (CS 4 h), CS 4 h + SP600125, CS 2 h + HMP 2 h, and CS 2 h + HMP 2 h + SP600125 groups. Donor livers in the CS 4 h and CS 4 h + SP600125 groups were conventionally cold preserved for 4 h, whereas donor livers in the CS 2 h + HMP 2 h and CS 2 h + HMP 2 h + SP600125 groups were cold preserved for 2 h and then treated with HMP for 2 h. The preservation and perfusion solutions contained SP600125 (20 µM). Follow-up was conducted for 5 days after liver transplantation to compare the surgical outcomes by means of serological examination, pathological results, and survival rate.

RESULTS

The most satisfactory outcome after liver transplantation was observed in the CS 2 h + HMP 2 h + SP600125 group, which presented with minimal damage of donor livers during 5 days' follow-up. Additionally, serological examination, pathological results, and survival rate concurred in showing better results in the CS 2 h + HMP 2 h ± SP600125 group than in the CS 4 h ± SP600125 group.

CONCLUSION

HMP in combination with SP600125 has hepatoprotective properties and improves the quality and viability of porcine livers collected after DCD, thus improving prognosis after liver transplantation.

Deceased Donor Predictors for Pediatric Liver Allograft Utilization

BACKGROUND

The number of pediatric deceased organ donors has recently declined, and the nonutilization of pediatric liver allografts has limited the development of liver transplantation. We determined the utilization rate of pediatric livers and identified risk factors for graft discard.

METHODS

We used data from the Scientific Registry of Transplant Recipients database from January 1, 2000, to December 31, 2012. The trends of pediatric liver donors and utilization rates were analyzed. Donor risk factors that impacted the graft use of pediatric livers were measured. Logistic regression modelling was performed to evaluate graft utilization and risk factors.

RESULTS

A total of 11,934 eligible pediatric liver donors were identified during this period. A total of 1191 authorized liver grafts did not recover or recovered without transplantation. Factors including pediatric donors >1 year of age (odds ratio [OR] = 2.956, 95% confidence interval [CI] 2.494-3.503, P < .001), nonhead trauma (OR = 2.243, 95% CI 1.903-2.642, P < .001), lack of heartbeat (OR = 7.534, 95% CI 5.899-9.623, P < .001), hepatitis B surface antigen positivity (OR = 4.588, 95% CI 1.021-20.625, P = .047), anti-hepatitis C virus positivity (OR = 4.691, 95% CI 1.352-16.280, P = .015), total bilirubin >1 mg/dL (OR = 1.743, 95% CI 1.469-2.068, P < .001), and blood urea nitrogen >21 mg/dL (OR = 1.941, 95% CI 1.546-2.436, P < .001) were significantly related to graft nonutilization. Steroids or diuretics administered prerecovery were significantly related to graft utilization (OR = 0.684, 95% CI 0.581-0.806, P < .001; OR = 0.744, 95% CI 0.634-0.874, P < .001; respectively).

CONCLUSIONS

The pediatric liver allograft utilization rate and risk factors for nonutilization of grafts were determined.

Tissues from Post-Mortem Donors as Alternative Sources of Stem Cells for Regenerative Medicine

Stem cells provide for all of the tissues in our body during embryogenesis. In adult organisms, they can be found as rare populations of tissue-specific stem cells in quiescent states, although they can still regenerate damaged tissues. Astonishingly, these cells are retained in tissues even post-mortem. There have been several reports that have provided evidence that cells with stem-like capabilities can be isolated, expanded, and differentiated in vitro from various tissues several hours, or even several days, post-mortem. Moreover, some post-mortem-tissue-derived stem cells can successfully engraft and regenerate injured host tissues. Here, we review in-vitro and in-vivo studies that provide evidence of isolation and characterization of stem cells from different tissues post-mortem, with a focus on the musculoskeletal and neural systems. Finally, we discuss their potential for use in regenerative medicine, and what needs to be done in further research toward their better exploitation.

Normothermic Machine Perfusion (NMP) Inhibits Proinflammatory Responses in the Liver and Promotes Regeneration

Liver transplantation (LT) is a successful treatment for patients with liver failure. However, organ shortage results in over 11% of patients losing their chance of a transplant attributed to liver decompensation (LD) and death. Ischemia/reperfusion injury (IRI) following conventional cold storage (CS) is a major cause of injury leading to graft loss after LT. Normothermic machine perfusion (NMP), a method of organ preservation, provides oxygen and nutrition during preservation and allows aerobic metabolism. NMP has recently been shown to enable improved organ utilization and posttransplant outcomes following a phase I and a phase III randomized trial. The aim of the present study is to assess the impact of NMP on reducing IRI and to define the underlying mechanisms. We transplanted and compared 12 NMP with 27 CS-preserved livers by performing gene microarray, immunoprofiling of hepatic lymphocytes, and immunochemistry staining of liver tissues for assessing necrosis, platelet deposition, and neutrophil infiltration, and the status of steatosis after NMP or CS prereperfusion and postreperfusion. Recipients receiving NMP grafts showed significantly lower peak aspartate aminotransferase (AST) levels than those receiving CS grafts. NMP altered gene-expression profiles of liver tissue from proinflammation to prohealing and regeneration. NMP also reduced the number of interferon gamma (IFN-γ) and interleukin (IL)-17-producing T cells and enlarged the CD4^pos CD25^high CD127^neg FOXP3^pos regulatory T cell (Treg) pool. NMP liver tissues showed less necrosis and apoptosis in the parenchyma and fewer neutrophil infiltration compared to CS liver tissues. Conclusion: Reduced IRI in NMP recipients was the consequence of the combination of inhibiting inflammation and promoting graft regeneration.

From deceased to bioengineered graft: New frontiers in liver transplantation

In the worldwide context of graft shortage, several strategies have been explored to increase the number of grafts available for liver transplantation (LT). These include the use of marginal and living donors, split livers, and the improvement of marginal donor grafts (machine perfusion). However, recent advances in the understanding of liver organogenesis, stem cells, and matrix biology provide novel insights in tissue engineering. Today, the newest technologies and discoveries open the door to the development of new methods for organ implementation such as the recellularization of natural scaffolds, liver organoids, bio-printing, and tissue or generation of chimeric organs. These approaches might potentially to generate an unlimited source of grafts (allogenic or chimeric) which will be used in the near future for LT or as a temporary bridge toward LT. This qualitative review focuses on all methods of organ implementation and highlights the newest developments in tissue engineering and regenerative medicine.

Control of Ischemia-Reperfusion Injury in Liver Transplantation: Potentials for Increasing the Donor Pool

Background

Organ shortage is a growing problem, with a rising number of organs being harvested from extended criteria donors, and this trend will further continue to increase as organ donors are getting older and have more comorbidities. Since this fact is immutable, efforts have been made to reduce the extent of ischemia-reperfusion injury (IRI) as well as of direct and indirect harvest-related graft injury which affects all organs in a more or less distinct way.

Methods

In liver transplantation (LT), the activation of Kupffer cells during organ reperfusion, thus provoking microcirculatory disturbances, hypoxia, and endothelial cell injury, is one of the key mechanisms causing graft dysfunction. Multiple approaches have been taken in order to find efficient preconditioning methods by pharmacological pretreatment, controlled induction of ischemia, controlled denervation of donor organs, and reconditioning with machine perfusion to prevent IRI, whereas marginal organs (i.e. steatotic grafts) are especially vulnerable.

Results

The above-mentioned approaches have been pursued in experimental and clinical settings. At this time point, however, there is not yet enough clinical evidence available to recommend any particular drug pretreatment or any other intervention for organ preconditioning prior to transplantation.

Conclusion

The multifactorial pathophysiology in the setting of IRI in LT requires a multimodal therapeutic approach with the integration of pharmacological and technical means being applied to the donor, the organ per se, and the recipient. Currently, there is no consensus on standardized pretreatment of donor organs in order to improve the transplant outcome.

Early Outcomes of Liver Transplantation Using Donors After Circulatory Death in Patients With Hepatocellular Carcinoma: A Comparative Study

INTRODUCTION

Donation after circulatory death (DCD) has increased in the last decade, although a slight increase in surgical complications has been reported in liver transplantation (LT). Therefore, DCD is not overall recommended because it entails an added risk. However, DCD in selected patients shows acceptable results.

OBJECTIVE

The objective was to analyze the characteristics, early outcomes, and survival at 1 year post-LT from a single institute (January 2015 to May 2017).

MATERIALS AND METHODS

We included 18 DCD-LTs and compared them with a control group of 18 donation after brain death (DBD) LTs. We analyzed pre- and posttransplant variables related to donors, recipients, and intraoperative early outcomes within patients transplanted due to hepatocellular carcinoma (HCC). A descriptive analysis, Mann-Whitney U test, χ², or Fisher test was performed when appropriate, as well as multivariate analysis in case of statistical significance. A variable is considered as statistically significant when it reaches a value of P < .05.

RESULTS

In DBD, we found a lower length of stay in the intensive care unit before retrieval and a higher rate of alcoholism and diabetes mellitus, Model for End-Stage Liver Disease score, and Child B and C score (P < .05). Most of the DCD were originally from the same LT recipient center, and a higher donor mean post-LT alanine aminotransferase level was found (P < .05). Survival for the DBD group was 88% and 75% in the DCD group at 1 year post-LT, being not significant (NS).

CONCLUSION

HCC recipients who are transplanted with good quality DCD livers do no worse than those transplanted with livers from DBD donors, although a good selection of them is crucial.

Donor liver quality after hypovolemic shock and venous systemic oxygen persufflation in an experimental animal model

BACKGROUND

The ever growing demand for liver transplantation inevitably necessitates an expansion of the donor pool. Utilization of "shock organs" is considered suboptimal to date while the associated outcome has hardly been investigated.

MATERIALS AND METHODS

Male Wistar rats underwent a period of 30 min of hypovolemic shock. After 24 h livers were explanted and prior to reperfusion underwent either 18 h of cold storage (CS; N = 6) or 17 h of CS followed by 60 min venous systemic oxygen persufflation (VSOP; N = 6). The outcome of "shock organs (SHBD)" was compared to heart-beating donor (HBD; N = 12) as positive control and non-heart-beating donor (NHBD; N = 12) as negative control animal groups. Liver function was assessed by measuring enzyme release (AST, ALT, LDH), bile production, portal vein pressure and hepatic oxygen uptake during reperfusion. For reperfusion, the isolated perfused rat liver system was used.

RESULTS

Liver function was severely limited in NHBD group compared to HBD organs after 18 h of CS (e.g., AST; HBD: 32.25 ± 7.25 U/l vs. NHBD: 790 ± 414.56 U/l; p < 0.005). VSOP improved liver function of NHBD organs significantly (AST; NHBD + VSOP: 333.6 ± 149.1 U/l; p < 0.005). SHBD organs showed a comparable outcome to HBD and clearly better results than NHBD organs after 18 h of CS (AST; SHBD: 76.4 ± 21.9 U/l). After 17 h of CS accompanied by 60 min VSOP, no improvement concerning liver function and integrity of SHBD organs was observed while the results were severely deteriorated by VSOP resulting in higher enzyme release (AST; SHBD + VSOP: 213 ± 61 U/l, p < 0.001), higher portal vein pressure (SHBD: 10.8 ± 1.92 mm Hg vs. SHBD + VSOP: 21.6 ± 8.8 mm Hg; p < 0.05) and lower hepatic oxygen uptake (SHBD: 321.75 ± 3.87 ml/glw/min vs. SHBD + VSOP: 395.8 ± 46.64 ml/glw/min, p < 0.05) at 24 h.

CONCLUSIONS

Our data suggest that the potential of "shock organs" within liver transplantation may be underestimated. If our findings are reproducable in humans, SHBD grafts should be considered as a valuable source for expanding the thus far limited donor pool.

Challenges and future developments in liver transplantation

Liver transplantation (LT) has become the treatment of choice for a wide range of liver diseases in both adult and pediatric patients. Until recently, the largest proportion of LT in adults, were performed in patients with hepatitis C (HCV) related cirrhosis. The recent availability of safe and effective direct antiviral agents to cure HCV infection in almost all patients whatever the HCV genotype and severity of liver disease, will reduce the need for LT in this category of recipients. Thus, it is presumed that in the next 1 to 2 decades HCV related liver disease will diminish substantially, whereas non-alcoholic steato-hepatitis (NASH) will correspondingly escalate as an indication for LT. The greatest challenges facing LT remain the limited supply of donor organs, and the need for chronic immunosuppression, which represent the true obstacles to the greater application and durable success of the LT procedure. This review aimed to highlight, in different sections, the main open issues and future developments in LT. These will be focused to explore current and future strategies to maximize the use of limited organs, to offer an update on potential new approaches to immunosuppression and to imagine new indications for LT when the number of patients awaiting transplants for HCV related liver disease is reduced.

Prediction of rat liver transplantation outcomes using energy metabolites measured by microdialysis

BACKGROUND

Warm ischemia jeopardizes graft quality and recipient survival in donation after cardiac death (DCD) transplantation. Currently, there is no system to objectively evaluate the liver quality from DCD. The present study tried to use energy metabolites to evaluate the donor liver quality.

METHODS

We divided 195 Sprague-Dawley rats into five groups: the control (n = 39), warm ischemic time (WIT) 15 min (n = 39), WIT 30 min (n = 39), WIT 45 min (n = 39), and WIT 60 min (n = 39) groups. Three rats from each group were randomly selected for pretransplant histologic evaluation of warm ischemia-related damage. The remaining 36 rats were randomly divided into donors and recipients of 18 liver transplantations, and were subjected to postoperative liver function and survival analyses. Between cardiac arrest and cold storage, liver energy metabolites including glucose, lactate, pyruvate, and glycerol were measured by microdialysis. The lactate to pyruvate ratio (LPR) was calculated.

RESULTS

The changes in preoperative pathology with warm ischemia were inconspicuous, but the trends in postoperative pathology and aminotransferase levels were consistent with preoperative energy metabolite measurements. The 30-day survival rates of the control and WIT 15, 30, 45, and 60 min groups were 100%, 81.82%, 76.92%, 58.33%, and 25.00%, respectively. The areas under the receiver operating characteristic curves of glucose, lactate, glycerol, and LPR were 0.87, 0.88, 0.88, and 0.92, respectively.

CONCLUSION

Glucose, lactate, glycerol, and LPR are predictors of graft quality and survival outcomes in DCD transplantation.

Normothermic Machine Preservation of the Liver: State of the Art

Purpose of Review

This review aims to introduce the concept of normothermic machine perfusion (NMP) and its role in liver transplantation. By discussing results from recent clinical studies and highlighting the potential opportunities provided by this technology, we aim to provide a greater insight into NMP and the role it can play to enhance liver transplantation.

Recent Findings

NMP has recently been shown to be both safe and feasible in liver transplantation and has also demonstrated its superiority to traditional cold storage in terms of early biochemical liver function. Through the ability to perform a viability assessment during preservation and extend preservation times, it is likely that an increase in organ utilisation will follow. NMP may facilitate the enhanced preservation with improved outcomes from donors after cardiac death and steatotic livers. Furthermore, it provides the exciting potential for liver-directed therapeutic interventions.

Summary

Evidence to date suggests that NMP facilitates the enhanced preservation of liver grafts with improved early post-transplant outcomes. The key role for this technology is to increase the number and quality of liver grafts available for transplantation and to reduce waiting list deaths.

Developing a donation after cardiac death risk index for adult and pediatric liver transplantation

AIM

To identify objective predictive factors for donor after cardiac death (DCD) graft loss and using those factors, develop a donor recipient stratification risk predictive model that could be used to calculate a DCD risk index (DCD-RI) to help in prospective decision making on organ use.

METHODS

The model included objective data from a single institute DCD database (2005-2013, n = 261). Univariate survival analysis was followed by adjusted Cox-regressional hazard model. Covariates selected via univariate regression were added to the model via forward selection, significance level P = 0.3. The warm ischemic threshold was clinically set at 30 min. Points were given to each predictor in proportion to their hazard ratio. Using this model, the DCD-RI was calculated. The cohort was stratified to predict graft loss risk and respective graft survival calculated.

RESULTS

DCD graft survival predictors were primary indication for transplant (P = 0.066), retransplantation (P = 0.176), MELD > 25 (P = 0.05), cold ischemia > 10 h (P = 0.292) and donor hepatectomy time > 60 min (P = 0.028). According to the calculated DCD-RI score three risk classes could be defined of low (DCD-RI < 1), standard (DCD-RI 2-4) and high risk (DCD-RI > 5) with a 5 years graft survival of 86%, 78% and 34%, respectively.

CONCLUSION

The DCD-RI score independently predicted graft loss (P < 0.001) and the DCD-RI class predicted graft survival (P < 0.001).

Current challenges and future directions for liver transplantation

Liver transplantation is an effective and widely used therapy for several patients with acute and chronic liver diseases. The discrepancy between the number of patients on the waiting list and available donors remains the key issue and is responsible for the high rate of waiting list mortality. The recent news is that the majority of patients with hepatitis C virus related liver disease will be cured by new antivirals therefore we should expect soon a reduction in the need of liver transplantation for these recipients. This review aims to highlight, in two different sections, the main open issues of liver transplantation concerning the current and future strategies to the best use of limited number of organs. The first section cover the strategies to increase the donor pool, discussing the use of older donors, split grafts, living donation and donation after cardiac death and mechanical perfusion systems to improve the preservation of organs before liver transplantation. Challenges in immunosuppressive therapy and operational tolerance induction will be evaluated as potential tools to increase the survival in liver transplant recipients and to reducing the need of re-transplantation. The second section is devoted to the evaluation of possible new indications to liver transplantation, where the availability of organs by implementing the strategies mentioned in the first section and the reduction in the number of waiting transplants for HCV disease is realized. Among these new potential indications for transplantation, the expansion of the Milan criteria for hepatocellular cancer is certainly the most open to question.

Donations After Circulatory Death in Liver Transplant

The supply of liver grafts for treatment of end-stage liver disease continues to fall short of ongoing demands. Currently, most liver transplants originate from donations after brain death. Enhanced utilization of the present resources is prudent to address the needs of the population. Donation after circulatory or cardiac death is a mechanism whereby the availability of organs can be expanded. Donations after circulatory death pose unique challenges given their exposure to warm ischemia. Technical principles of donations after circulatory death procurement and pertinent studies investigating patient outcomes, graft outcomes, and complications are highlighted in this review. We also review associated risk factors to suggest potential avenues to achieve improved outcomes and reduced complications. Future considerations and alternative techniques of organ preservation are discussed, which may suggest novel strategies to enhance preservation and donor expansion through the use of marginal donors. Ultimately, without effective measures to bolster organ supply, donations after circulatory death should remain a consideration; however, an understanding of inherent risks and limitations is necessary.

Lipidomics comparing DCD and DBD liver allografts uncovers lysophospholipids elevated in recipients undergoing early allograft dysfunction

Finding specific biomarkers of liver damage in clinical evaluations could increase the pool of available organs for transplantation. Lipids are key regulators in cell necrosis and hence this study hypothesised that lipid levels could be altered in organs suffering severe ischemia. Matched pre- and post-transplant biopsies from donation after circulatory death (DCD, n = 36, mean warm ischemia time = 2 min) and donation after brain death (DBD, n = 76, warm ischemia time = none) were collected. Lipidomic discovery and multivariate analysis (MVA) were applied. Afterwards, univariate analysis and clinical associations were conducted for selected lipids differentiating between these two groups. MVA grouped DCD vs. DBD (p = 6.20 × 10(-12)) and 12 phospholipids were selected for intact lipid measurements. Two lysophosphatidylcholines, LysoPC (16:0) and LysoPC (18:0), showed higher levels in DCD at pre-transplantation (q < 0.01). Lysophosphatidylcholines were associated with aspartate aminotransferase (AST) 14-day post-transplantation (q < 0.05) and were more abundant in recipients undergoing early allograft dysfunction (EAD) (p < 0.05). A receiver-operating characteristics (ROC) curve combining both lipid levels predicted EAD with 82% accuracy. These findings suggest that LysoPC (16:0) and LysoPC (18:0) might have a role in signalling liver tissue damage due to warm ischemia before transplantation.

Presentation, diagnosis, and management of early hepatic venous outflow complications in whole cadaveric liver transplant

Early hepatic venous outflow obstruction (HVOO) can be a devastating complication leading to graft loss after liver transplantation (LT). A retrospective study on 777 adult LT recipients over a 5-year period (August 2007 to August 2012) was undertaken to determine the incidence of early HVOO presenting within 3 months of transplant, its clinical features and management, and potential technical risk factors related to the implanting technique. Cases of early HVOO were screened for by identifying recipients with problematic ascites within 3 months of transplant. Definitive diagnosis for HVOO was based on a wedge pressure of >12 mm Hg. Considering only whole livers, the incidence of early problematic ascites was 3% (20/695) of which more than one-third (35%, 7/20) were then confirmed to have HVOO. Overall, the incidence of early HVOO was 1% (7/695). Two hepatic veins (HVs) with extension piggybacks (PBs; n = 423) were the dominant implanting technique in the time period of study rather than the 3 HV PB (n = 182) and caval replacement techniques (n = 82). Considering the implantation technique, all cases of HVOO occurred after 2 HVs when extension PBs had been used with an incidence of 1.7% (7/423). Institutionally, early HVOO was mainly managed surgically by either cavoplasty within a month of transplant (n = 4) or retransplant (n = 1), and the remainder (n = 2) were medically managed with diuretics. In conclusion, early HVOO is rare, and there is no evidence from this study that a given implantation technique is at a higher risk of developing HVOO (2 HV with extension versus 3 HV and caval replacement; P = 0.11). However, early revisional surgery for HVOO can preserve graft function with retransplantation being reserved for when surgical cavoplasty or radiological stenting is technically not possible.

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

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

Safely expanding the donor pool: brain dead donors with history of temporary cardiac arrest

BACKGROUND & AIMS

Cardiac arrest (CA) in deceased organ donors can potentially be associated with ischaemic organ injury, resulting in allograft dysfunction after liver transplantation (LT). The aim of this study was to analyse the influence of cardiac arrest in liver donors.

METHODS

We evaluated 884 consecutive adult patients undergoing LT at our Institution from September 2003 to December 2011. Uni- and multivariable analyses was performed to identify predictive factors of outcome and survival for organs from donors with (CA donor) and without (no CA donor) a history of cardiac arrest.

RESULTS

We identified 77 (8.7%) CA donors. Median resuscitation time was 16.5 (1-150) minutes. Allografts from CA donors had prolonged CIT (p = 0.016), were obtained from younger individuals (p < 0.001), and had higher terminal preprocurement AST and ALT (p < 0.001) than those of no CA donors. 3-month, 1-year and 5-year survival for recipients of CA donor grafts was 79%, 76% and 57% and 72.1%, 65.1% and 53% for no CA donor grafts (log rank p = 0.435). Peak AST after LT was significantly lower in CA donor organs than in no CA donor ones (886U/l vs 1321U/l; p = 0.031). Multivariable analysis identified CIT as a risk factor for both patient and graft survival in CA donors.

CONCLUSION

This analysis represents the largest cohort of liver donors with a history of cardiac arrest. Reasonable selection of these donors constitutes a safe approach to the expansion of the donor pool. Rapid allocation and implantation with diminution of CIT may further improve the outcomes of livers from CA donors.

French survey of the first three-years of liver transplantation activity from uncontrolled donors deceased after cardiac death

OBJECTIVE

To assess the first three years of French activity related to liver transplantation from uncontrolled donation after cardiac death (uDCD).

STUDY DESIGN

Prospective and observational study in the three active centres authorized by the French Biomedicine Agency.

PATIENTS AND METHODS

All patients deceased between 2010 and 2012 after an uncontrolled cardiac arrest admitted to one of three centres (Pitié-Salpêtrière, Saint-Louis or Bicêtre hospitals, AP-HP, Paris, France) and potentially eligible for liver recovery were included. Abdominal normothermic oxygenated recirculation (ANOR) was used for graft preservation.

RESULTS

One hundred twenty-six potential uDCD donors were identified as eligible for liver recovery after hospital admission. The main causes of organ recovery failure were technical failure related to ANOR (29 patients, 23%), refusal of consent (39 patients, 31% of potential uDCD donors and 40% of asked relatives) and abnormal hepatic transaminases up to 200 UI.L(-1) during ANOR (24 patients, 19%). Finally, 11 livers were transplanted. Process efficiency was 9% [95% CI: 4-15%]. One-year recipient survival was 82%, [95% CI: 48-98%] and one-year graft survival was 64% [95% CI: 31-89%].

CONCLUSION

Liver transplantation from uDCD donors is achievable in France, despite low process efficiency.

The bile duct in donation after cardiac death donor liver transplant

PURPOSE OF REVIEW

This review considers the biliary complications associated with liver transplantation using donation after cardiac death (DCD) donor grafts.

RECENT FINDINGS

The increasing use of DCD liver grafts with their increased incidence of biliary complications is discussed. The ethics of this greater use is briefly analysed. Recent animal and human study evidence to support the peribiliary vascular plexus' role in ischaemic cholangiopathy is reviewed. Recent advances in in-vivo and ex-vivo perfusion are explored. In particular, the latest theories regarding perfusion's peribiliary plexus preserving effects and the mechanism by which biliary regeneration may be promoted as a consequence are discussed.

SUMMARY

This article explores the need for DCD liver graft use and the associated biliary complications. The current theories regarding the cause of DCD biliary complications are reviewed, as are the current strategies to reduce them.

Solutions to shortage of liver grafts for transplantation

Increasing the donor supply

Donor age as a risk factor in donation after circulatory death liver transplantation in a controlled withdrawal protocol programme

BACKGROUND

Results of donation after circulatory death (DCD) liver transplantation are impaired by graft loss, resulting mainly from non-anastomotic biliary stricture. Donor age is a risk factor in deceased donor liver transplantation, and particularly in DCD liver transplantation. At the authors' institute, age is not an absolute exclusion criterion for discarding DCD liver grafts, DCD donors receive comfort therapy before withdrawal, and cold ischaemia is minimized.

METHODS

All consecutive DCD liver transplantations performed from 2003 to 2012 were studied retrospectively. Three age groups were compared in terms of donor and recipient demographics, procurement and transplantation conditions, peak laboratory values during the first post-transplant 72 h, and results at 1 and 3 years.

RESULTS

A total of 70 DCD liver transplants were performed, including 32 liver grafts from donors aged 55 years or less, 20 aged 56-69 years, and 18 aged 70 years or more. The overall graft survival rate at 1 month, 1 and 3 years was 99, 91 and 72 per cent respectively, with no graft lost secondary to non-anastomotic stricture. No difference other than age was noted between the three groups for donor or recipient characteristics, or procurement conditions. No primary non-function occurred, but one patient needed retransplantation for artery thrombosis. Biliary complications were similar in the three groups. Graft and patient survival rates were no different at 1 and 3 years between the three groups (P = 0.605).

CONCLUSION

Results for DCD liver transplantation from younger and older donors were similar. Donor age above 50 years should not be a contraindication to DCD liver transplantation if other donor risk factors (such as warm and cold ischaemia time) are minimized.

HOPE for human liver grafts obtained from donors after cardiac death

BACKGROUND & AIMS

Due to ethical rules in most countries, long ischemia times are unavoidable prior to organ procurement of donors without a heartbeat, which can cause early graft failure after liver transplantation or late biliary strictures. Hypothermic oxygenated machine perfusion, used prior to graft implantation, may rescue these high risk organs.

METHODS

Eight patients with end stage liver diseases received human livers, obtained after controlled cardiac death (Maastricht category III), with a median donor warm ischemia time of 38 min, followed by a standard cold flush and static storage at 4 °C. Hypothermic oxygenated perfusion (HOPE) was applied for 1-2h prior to implantation through the portal vein. The HOPE-perfusate was cooled at 10 °C and oxygenated (pO2 60 kPa) using an ECOPS device (Organ Assist®). Perfusion pressure was maintained below 3 mmHg.

RESULTS

Each machine perfused liver graft disclosed excellent early function after transplantation. The release of liver enzymes and kidney function, as well as ICU and hospital stays were comparable or better than in matched liver grafts from brain death donors. No evidence of intrahepatic biliary complications could be documented within a median follow up of 8.5 months.

CONCLUSIONS

This is the first report on cold machine perfusion of human liver grafts obtained after cardiac arrest and subsequent transplantation. Application of HOPE appears well tolerated, easy-to-use, and protective against early and later injuries.

Increasing the donor pool: consideration of prehospital cardiac arrest in controlled donation after circulatory death for liver transplantation

Donor warm ischemia has implications for outcomes after liver transplantation (LT) using organs from donation after circulatory death (DCD) donors. Prehospital cardiac arrest (PHCA) before donation may generate a further ischemic insult. The aim of this single-center study of 108 consecutive DCD LT procedures was to compare the outcomes of PHCA and non-PHCA cohorts. A review of a prospectively collected database of all DCD grafts transplanted between January 2007 and October 2011 was undertaken to identify donors who had sustained PHCA. The unit policy was to consider such donors when transaminase levels were ≤4 times the normal range and had an improving trend. Twenty-six of the 108 DCD transplants were from DCD donors with PHCA, and 82 were in the non-PHCA cohort. A comparative analysis of the PHCA and non-PHCA cohorts showed better short-term results (a low incidence of acute kidney injury) for the PHCA group but satisfactory long-term results for both groups with no significant differences in graft or patient survival between them. In conclusion, a careful donor selection policy for including PHCA DCD donors with normalized liver function tests or transaminase levels ≤ 4 times the norm resulted in successful transplantation and could boost the donor pool with no adverse outcomes.

Regional perfusion by extracorporeal membrane oxygenation of abdominal organs from donors after circulatory death: a systematic review

Organs from donors after circulatory death (DCDs) are particularly susceptible to the effects of warm ischemia injury. Regional perfusion (RP) by extracorporeal membrane oxygenation (ECMO) is increasingly being advocated as a useful remedy to the effects of ischemia/reperfusion injury, and it has been reported to enable the transplantation of organs from donors previously deemed unsuitable. The MEDLINE, Embase, and Cochrane databases were searched, and articles published between 1997 and 2013 were obtained. A systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Two hundred ten articles were identified, and 11 were eligible for inclusion. Four hundred eighty-two kidneys and 79 livers were transplanted from regional perfusion-supported donor after circulatory death (RP-DCD) sources. One-year graft survival was lower with uncontrolled RP-DCD liver transplantation, whereas 1-year patient survival was similar. Primary nonfunction and ischemic cholangiopathy were significantly more frequent with RP-DCDs versus donors after brain death (DBDs), but there was no difference in postoperative mortality between the 2 groups. The 1-year patient and graft survival rates for RP-DCD kidney transplantation were better than the rates with standard DCDs and were comparable to, if not better than, the rates with DBDs. At experienced centers, delayed graft function (DGF) for kidney transplantation from RP-DCDs was much less frequent in comparison with all other donor types. In conclusion, RP aids the recovery of DCD organs from ischemic injury and enables transplantation with acceptable survival. RP may help to increase the donor pool, but its benefits must still be balanced with the recognition of significantly higher rates of complications in liver transplantation. In kidney transplantation, significant reductions in DGF can be obtained with RP, and there are potentially important implications for long-term outcomes. Significant ethicolegal issues exist, and they are preventing a worldwide consensus on optimum RP protocols and an accurate appreciation of outcomes.

Changing pattern of donor selection criteria in deceased donor liver transplant: a review of literature

During the last couple of decades, with standardization and progress in surgical techniques, immunosuppression and post liver transplantation patient care, the outcome of liver transplantation has been optimized. However, the principal limitation of transplantation remains access to an allograft. The number of patients who could derive benefit from liver transplantation markedly exceeds the number of available deceased donors. The large gap between the growing list of patients waiting for liver transplantation and the scarcity of donor organs has fueled efforts to maximize existing donor pool and identify new avenues. This article reviews the changing pattern of donor for liver transplantation using grafts from extended criteria donors (elderly donors, steatotic donors, donors with malignancies, donors with viral hepatitis), donation after cardiac death, use of partial grafts (split liver grafts) and other suboptimal donors (hypernatremia, infections, hypotension and inotropic support).

Challenges in machine perfusion preservation for liver grafts from donation after circulatory death

Donation after circulatory death (DCD) is a promising solution to the critical shortage of donor graft tissue. Maintaining organ viability after donation until transplantation is essential for optimal graft function and survival. To date, static cold storage is the most widely used form of preservation in clinical practice. However, ischemic damage present in DCD grafts jeopardizes organ viability during cold storage, and whether static cold storage is the most effective method to prevent deterioration of organ quality in the increasing numbers of organs from DCD is unknown. Here we describe the historical background of DCD liver grafts and a new preservation method for experimental and clinical transplantation. To prevent ischemia-reperfusion injury in DCD liver grafts, a hypothermic machine perfusion (HMP) technique has recently been developed and may be superior to static cold preservation. We present evidence supporting the need for improving liver perfusion performance and discuss how doing so will benefit liver transplantation recipients.

Outcomes of transplantation of livers from donation after circulatory death donors in the UK: a cohort study

OBJECTIVES

Outcomes of liver transplantations from donation after circulatory death (DCD) donors may be inferior to those achieved with donation after brain death (DBD) donors. The impact of using DCD donors is likely to depend on specific national practices. We compared risk-adjusted graft loss and recipient mortality after transplantation of DCD and DBD livers in the UK.

DESIGN

Prospective cohort study. Multivariable Cox regression and propensity score matching were used to estimate risk-adjusted HR.

SETTING

7 liver transplant centres in the National Health Service (NHS) hospitals in England and Scotland.

PARTICIPANTS

Adults who received a first elective liver transplant between January 2005 and December 2010 who were identified in the UK Liver Transplant Audit.

INTERVENTIONS

Transplantation of DCD and DBD livers.

OUTCOMES

Graft loss and recipient mortality.

RESULTS

In total, 2572 liver transplants were identified with 352 (14%) from DCD donors. 3-year graft loss (95% CI) was higher with DCD livers (27.3%, 21.8% to 33.9%) than with DBD livers (18.2%, 16.4% to 20.2%). After adjustment with regression, HR for graft loss was 2.3 (1.7 to 3.0). Similarly, 3-year mortality was higher with DCD livers (19.4%, 14.5% to 25.6%) than with DBD livers (14.1%, 12.5% to 16.0%) with an adjusted HR of 2.0 (1.4 to 2.8). Propensity score matching gave similar results. Centre-specific adjusted HRs for graft loss and recipient mortality seemed to differ among transplant centres, although statistical evidence is weak (p value for interaction 0.08 and 0.24, respectively).

CONCLUSIONS

Graft loss and recipient mortality were about twice as high with DCD livers as with DBD livers in the UK. Outcomes after DCD liver transplantation may vary between centres. These results should inform policies for the use of DCD livers.

Liver Transplantation: East versus West

Liver transplantation (LT) has evolved rapidly since the first successful liver transplant performed in1967. Despite a humble beginning, this procedure gained widespread acceptance in the western world as a suitable option for patients with end stage liver disease (ESLD) by the beginning of the 1980s. At present, approximately 25,000 liver transplants are being performed worldwide every year with approximately 90% one year survival. The techniques of living donor liver transplantation (LDLT) developed in East Asia in the 1990s to overcome the shortage of suitable grafts for children and scarcity of deceased donors. While deceased donor liver transplantation (DDLT) constitutes more than 90% of LT in the western world, in India and other Asian countries, most transplants are LDLT. Despite the initial disparity, outcomes following LDLT in eastern countries have been quite satisfactory when compared to the western programs. The etiologies of liver failure requiring LT vary in different parts of the world. The commonest etiology for acute liver failure (ALF) leading to LT is drugs in the west and acute viral hepatitis in Asia. The most common indication for LT due to ESLD in west is alcoholic cirrhosis and hepatitis C virus (HCV), while hepatitis B virus (HBV) predominates in the east. There is a variation in prognostic models for assessing candidature and prioritizing organ allocation across the world. Model for end-stage liver disease (MELD) is followed in United States and some European centers. Other European countries rely on the Child-Turcotte-Pugh (CTP) score. Some parts of Asia still follow chronological order of listing. The debate regarding the best model for organ allocation is far from over.

Successful auto-implantation of hepatic cells in lung tissue: An animal study

BACKGROUND

This study was proposed to evaluate a new method for autograft transplantation of liver tissue fragments (LTF) in the lung parenchyma and bronchus of dogs and to compare the results to find out if they are suitable sites for hepatocyte implantation or not.

MATERIALS AND METHODS

THE DOGS WERE RANDOMLY ASSIGNED INTO TWO CATEGORIES: LTF auto-transplantation to the lung parenchyma and into the bronchus. The suspensions of normal saline and LTF were injected and implanted into the lung parenchyma and the main bronchus of the right accessory lobe in first and second groups, respectively. Two weeks later the right accessory lobe was removed and sent for a histopathological study. All samples were checked under a light microscope with regard to the presence of hepatocytes, with both the Hematoxylin and Eosin (H and E) preparation and immunohistochemistry (IHC) method, using a CK-18 marker. All results were double-checked with a polymerase chain reaction (PCR).

RESULTS

The mean weight of all the dogs was 19.87 ± 0.93 kg and mean age was 3.58 ± 0.31 years. After 15 days, the H and E, IHC, and PCR studies revealed that in the first group, all the dogs (n = 4) had living liver tissue, which survived in the lung parenchyma successfully. In contrast, none of the dogs (n = 0) in the second group showed surviving hepatocytes in the bronchus (P < 0.001).

CONCLUSION

Implantation of the LTFs into the lung parenchyma could be a source of hepatic cell production.

Outcomes of liver transplantations using donations after circulatory death: a single-center experience

INTRODUCTION

Orthotopic liver transplantation (OLT) (LTx) using donation after circulatory death (DCD) donors is increasingly performed, but still considered to risk of poorer outcomes compared with standard donations after brain death (DBD)-OLT. Therefore we reviewed our results of DCD-OLT.

PATIENTS AND METHODS

Between 2003 and 2010, we performed 30 DCD-OLT (6% of all OLT). We retrospectively reviewed medical records of donors and recipients after DCD versus DBD-OLT to analyze biliary complications, retransplantation rates, and patient/graft survivals.

RESULTS

Median donor age was similar for DCD and DBD-OLT: 51 versus 53 years (P = .244). Median donor warm ischemia time (stop ventilation to cold perfusion in DCD donors) was 24 minutes. Median cold ischemia time was shorter for DCD (6 hours 54 minutes) compared with DBD-OLT (8 hours 36 minutes; P < .0001). Median laboratory model of end-stage liver disease score was 15 for DCD, and 16 for DBD-OLT (P = .59). Median post-OLT Aspartate Aminotransferase (AST) peak was higher after DCD: 1178 versus DBD-OLT 651 IU/L (P = .005). The incidence of nonanastomotic strictures was different: 33.3% for DCD versus 12.5% for DBD-OLT (P = .001). The overall retransplantation rate was 3% after both DCD and DBD-OLT. After DCD-LTx actuarial 1, 3- and 5-year patient survivals were 93, 85 and 85%, and corresponding graft survivals, 90%, 82%, and 82% respectively, and not different compared with DBD-OLT: 88%, 78%, and 72% (P = .348) and 85%, 74%, and 68% (P = .524) respectively.

CONCLUSION

Despite substantial ischemic injury (high peak AST and biliary strictures) short- and long-term survival after DCD-OLT was comparable to DBD-OLT. Rapid donor surgery, careful donor and recipient selection, as well as short warm and cold ischemia times are key factors to optimize outcomes after DCD-OLT. However, strategies to reduce biliary complications remain warranted.

Extracorporeal membrane oxygenation for resuscitation of deceased cardiac donor livers for hepatocyte isolation

BACKGROUND

Deceased cardiac donors (DCDs) have become a useful source of organs for liver transplantation; nevertheless, there are concerns about the longevity of these grafts. The aim of this study was to evaluate the use of extracorporeal membrane oxygenation (ECMO) to resuscitate DCD porcine livers as a preclinical model using hepatocyte isolation and viability as a marker to assess whole-graft preservation.

MATERIALS AND METHODS

We randomized Landrace pigs into three groups after cardiac death and 30 min of warm ischemia: group 1, peritoneal cooling with intravascular cooling for 2 h; group 2, ECMO for 2 h; and group 3, control (conventional intravascular cooling and retrieval). We then reperfused group 1 and 2 livers for 2 h on an ex vivo reperfusion circuit and isolated hepatocytes.

RESULTS

After reperfusion, hepatocyte viability was significantly improved in the ECMO group compared to the cooling groups, as measured by trypan blue, methylthiazolyldiphenyl-tetrazolium bromide, and seeding efficiency. Glycogen and reduced glutathione content were significantly used in the ECMO group both before and after reperfusion compared with group 2. The adenosine diphosphate:adenosine triphosphate ratio showed an improved trend (lower) in the ECMO group compared with the cooling group but did not reach statistical significance either before or after reperfusion.

CONCLUSIONS

This preclinical study suggests that ECMO is a viable technique for liver preservation that gives an improved yield of hepatocytes when isolated from a DCD liver, suggesting improved liver preservation.

Liver transplant using donors after cardiac death: a single-center approach providing outcomes comparable to donation after brain death

OBJECTIVES

Organ donation after cardiac death remains an available resource to meet the demand for transplant. However, concern persists that outcomes associated with donation after cardiac death liver allografts are not equivalent to those obtained with organ donation after brain death. The aim of this matched case control study was to determine if outcomes of liver transplants with donation after cardiac death donors is equivalent to outcomes with donation after brain death donors by controlling for careful donor and recipient selection, surgical technique, and preservation solution.

MATERIALS AND METHODS

A retrospective, matched case control study of adult liver transplant recipients at the University of Tennessee/Methodist University Hospital Transplant Institute, Memphis, Tennessee was performed. Thirty-eight donation after cardiac death recipients were matched 1:2, with 76 donation after brain death recipients by recipient age, recipient laboratory Model for End Stage Liver Disease score, and donor age to form the 2 groups. A comprehensive approach that controlled for careful donor and recipient matching, surgical technique, and preservation solution was used to minimize warm ischemia time, cold ischemia time, and ischemia-reperfusion injury.

RESULTS

Patient and graft survival rates were similar in both groups at 1 and 3 years (P = .444 and P = .295). There was no statistically significant difference in primary nonfunction, vascular complications, or biliary complications. In particular, there was no statistically significant difference in ischemic-type diffuse intrahepatic strictures (P = .107).

CONCLUSIONS

These findings provide further evidence that excellent patient and graft survival rates expected with liver transplants using organ donation after brain death donors can be achieved with organ donation after cardiac death donors without statistically higher rates of morbidity or mortality when a comprehensive approach that controls for careful donor and recipient matching, surgical technique, and preservation solution is used.

Donation after cardiac death: where, when, and how?

The continuing shortage of donors has led to the increasing use of marginal grafts. Surgical techniques such as split, domino, and living donations have not been able to decrease waiting list mortality. Donation after cardiac death (DCD) was the only source of grafts prior to the establishment of brain death criteria in 1968. Thereafter, donation after brain death emerged as the leading source of grafts. The context in which irreversible cessation of circulatory and respiratory functions happens was the cornerstone to definite the four categories of DCD by the First International Workshop on DCD held in Maastricht in 1995. Controlled (CDCD) and uncontrolled (UDCD) categories now account for 10%-20% of the donor pool in several countries. Despite initial high rates of primary nonfunction and ischemic-type biliary lesions, refinements in protocols and surgical techniques have led to excellent 1- and 3-year graft survivals of 80% and 70%, respectively with PNF and ITBL rates below 3%. The institution of UDCD and CDCD depends on legal considerations of presumed consent and withdrawal of maneuvers, respectively. The potential for DCD programs is huge; it may be the only real, effective way to increase the grafts pool, both in adult and pediatric populations. Recent advances in perfusion machines will surely optimize this donor pool and allow new therapies for graft resuscitation.

Utilization of expanded criteria donors in liver transplantation

Improvements in surgical techniques, immunosuppression, and post-transplantation patient care have led to the optimization of liver transplantation outcomes. However, the waiting list for liver transplantation is increasing at a greater pace. The large gap between the growing pool of patients waiting for liver transplantation and the scarcity of donor organs has fueled efforts to maximize existing donors and identify new sources. This article will be focused on the current state of liver transplantation using grafts from extended criteria donors (elderly donors, steatotic donors, donors with malignancies, donors with viral hepatitis) and from donation after cardiac death (DCD), as well as the use of partial grafts (split grafts and living-donor liver transplantation) and other suboptimal donors (donors with hypernatremia, infections, hypotension and inotropic support). Overall, broadened criteria for acceptable donor livers appear to lessen graft survival rates somewhat compared with rates for standard criteria organs.

Prediction models of donor arrest and graft utilization in liver transplantation from maastricht-3 donors after circulatory death

Shortage of organs for transplantation has led to the renewed interest in donation after circulatory-determination of death (DCDD). We conducted a retrospective analysis (2001-2009) and a subsequent prospective validation (2010) of liver Maastricht-Category-3-DCDD and donation-after-brain-death (DBD) offers to our program. Accepted and declined offers were compared. Accepted DCDD offers were divided into donors who went on to cardiac arrest and those who did not. Donors who arrested were divided into those producing grafts that were transplanted or remained unused. Descriptive comparisons and regression analyses were performed to assess predictor models of donor cardiac arrest and graft utilization. Variables from the multivariate analysis were prospectively validated. Of 1579 DCDD offers, 621 were accepted, and of these, 400 experienced cardiac arrest after withdrawal of support. Of these, 173 livers were transplanted. In the DCDD group, donor age < 40 years, use of inotropes and absence of gag/cough reflexes were predictors of cardiac arrest. Donor age >50 years, BMI >30, warm ischemia time >25 minutes, ITU stay >7 days and ALT ≥ 4× normal rates were risk factors for not using the graft. These variables had excellent sensitivity and specificity for the prediction of cardiac arrest (AUROC = 0.835) and graft use (AUROC = 0.748) in the 2010 prospective validation. These models can feasibly predict cardiac arrest in potential DCDDs and graft usability, helping to avoid unnecessary recoveries and healthcare expenditure.