Liver transplantation using controlled donation after cardiac death donors: an analysis of a large single-center experience

Current Understanding of Marginal Grafts in Liver Transplantation

End-stage liver disease (ESLD), stemming from a spectrum of chronic liver pathologies including chronic liver failure, acute cirrhosis decompensation and hepatocellular carcinoma, imposes a significant global healthcare burden. Liver transplantation (LT) remains the only treatment for ESLD. However, the escalating mortality on transplant waitlists has prompted the utilization of marginal liver grafts in LT procedures. These grafts primarily encompass elderly livers, steatotic livers, livers from donation after circulatory death, split livers and those infected with the hepatitis virus. While the expansion of the donor pool offers promise, it also introduces concomitant risks. These encompass graft failure, biliary and cardiovascular complications, the recurrence of liver disease and reduced patient and graft survival. Consequently, various established strategies, ranging from improved donor-recipient matching to surgical interventions, have emerged to mitigate these risks. This article undertakes a comprehensive assessment of the current landscape, evaluating the viability of diverse marginal liver grafts. Additionally, it synthesizes approaches aimed at enhancing the quality of such marginal liver grafts. The overarching objective is to augment the donor pool and ameliorate the risk factors associated with the shortage of liver grafts.

Strategies to Improve the Utilization and Function of DCD Livers

Despite the increased usage of livers from donation after circulatory death (DCD) donors in the last decade, many patients remaining on the waitlist who need a liver transplant. Recent efforts have focused on maximizing the utilization and outcomes of these allografts using advances in machine perfusion technology and other perioperative strategies such as normothermic regional perfusion (NRP). In addition to the standard donor and recipient matching that is required with DCD donation, new data regarding the impact of graft steatosis, extensive European experience with NRP, and the increasing use of normothermic and hypothermic machine perfusion have shown immense potential in increasing DCD organ overall utilization and improved outcomes. These techniques, along with viability testing of extended criteria donors, have generated early promising data to consider the use of higher-risk donor organs and more widespread adoption of these techniques in the United States. This review explores the most recent international literature regarding strategies to optimize the utilization and outcomes of DCD liver allografts, including donor-recipient matching, perioperative strategies including NRP versus rapid controlled DCD recovery, viability assessment of discarded livers, and postoperative strategies including machine perfusion versus pharmacologic interventions.

Dynamic liver preservation: Are we still missing pieces of the puzzle?

To alleviate the persistent shortage of donor livers, high-risk liver grafts are increasingly being considered for liver transplantation. Conventional preservation with static cold storage falls short in protecting these high-risk livers from ischemia-reperfusion injury, as evident from higher rates of post-transplant complications such as early allograft dysfunction and ischemic cholangiopathy. Moreover, static cold storage does not allow for a functional assessment of the liver prior to transplantation. To overcome these limitations, dynamic strategies of liver preservation have been proposed, designed to provide a protective effect while allowing pre-transplant functional assessment. In this review, we discuss how different dynamic preservation strategies exert their effects, where we stand in assessing liver function and what challenges are lying ahead.

Impact of Donation After Circulatory Death Allografts on Outcomes After Liver Transplant for Hepatitis C: A Single-Center Experience and Review of the Literature

OBJECTIVES

We investigated the impact of liver transplant from donors after circulatory death on incidence and severity of recurrent hepatitis C virus infection, graft and patient survival and aimed to identify predictors of outcomes.

MATERIALS AND METHODS

We retrospectively reviewed all liver transplants performed at a single center (July 2007-February 2014). Patients with hepatitis C who underwent liver transplant from donors after circulatory death (group 1) were compared with hepatitis C patients who received grafts from donors after brain death (group 2) and patients without hepatitis C who received grafts from donors after circulatory death (group 3).We used the Kaplan-Meier method for survival analysis and performed a multivariable analysis for predictors of outcomes using Cox regression. Competing risk was used to analyze hepatitis C recurrence.

RESULTS

Of 196 patients, 107 were included: 25 in group 1, 46 in group 2, and 36 in group 3. All 3 groups were comparable, except for longer cold ischemia time (P < .01) in group 1, lower Model for End-Stage Liver Disease score at transplant in groups 1 and 3 (P < .01), and greater proportion of recipients with hepatocellular carcinoma in groups 1 and 2 (P = .02). Hepatitis C recurrence and severe recurrence at 1 and 3 years were higher in group 1 (but not statistically significant). Severe recurrence was noted in 17% versus 8% at 1 year (P = .12) and 30% versus 14% at 3 years (P = .08). Graft and patient survival rates at 1, 3, and 5 years were comparable in all 3 study groups.

CONCLUSIONS

Recurrent hepatitis C, including severe recurrence, was greater following donation after circulatory death compared with donation after brain death liver transplant. However, graft survival and patient survival were comparable, including in recipients of donation after circulatory death grafts without hepatitis C.

Good post-transplant outcomes using liver donors after circulatory death when applying strict selection criteria: A propensity-score matched-cohort study

INTRODUCTION AND OBJECTIVES

Outcomes of liver transplantation (LT) with donors after circulatory death (DCD) have been considered suboptimal due to higher rates of ischemic cholangiopathy, especially when the super-rapid recovery (SRR) technique is used. This study aimed to compare the incidence of complications between recipients receiving DCD vs those receiving donors after brain death (DBD) in a large-volume liver transplant centre.

METHODS

We performed a retrospective cohort study (LT from January 2015 to December 2018) comparing recipients who underwent a LT with DCD vs. a control group of LT with DBD, matched 1:1 without replacement by propensity score matching that included the following variables: LT indication, recipient sex and age, donor age and MELD score.

RESULTS

51 recipients with DCD-LT (29 SRR, 22 normothermic regional perfusion [NRP]) were matched with 51 DBD-LT recipients. Biliary complications were more frequent in DCD, 10% (n=5), all with SRR technique, vs 2% (n=1) in the DBD group, p=0.2. Two patients (4%) suffered primary graft non-function in the DCD group (1 SRR and 1 NRP) versus zero in the DBD group (p=0.49). Postoperative bleeding and reinterventions were also higher in the DCD group: 7 (13.7%) vs 1 (1.95%) and 8 (15.7%) vs 2 (3.9%) respectively (p=0.06 and 0.09). On the 1^st postoperative day AST/ALT peak was higher in DCD (p≤0001). The incidence of rejection, vascular complications, renal injury, hospital stay, and readmissions were similar in both groups. Cumulative 1-, 2-, 3- and 4-year graft and patient survival were also similar.

CONCLUSIONS

DCD donors are an adequate option to increase the donor pool in LT, achieving similar graft and patient survival rates to those achieved with DBD donors, especially when the NRP technique is used.

Lost potential and missed opportunities for DCD liver transplantation in the United States

BACKGROUND

Donation after cardiac death(DCD) has been proposed as an avenue to expand the liver donor pool.

METHODS

We examined factors associated with nonrecovery of DCD livers using UNOS data from 2015 to 2019.

RESULTS

There 265 non-recovered potential(NRP) DCD livers. Blood type AB (7.8% vs. 1.1%) and B (16.9% vs. 9.8%) were more frequent in the NRP versus actual donors (p < 0.001). The median driving time between donor hospital and transplant center was similar for NRP and actual donors (30.1 min vs. 30.0 min; p = 0.689), as was the percentage located within a transplant hospital (20.8% vs. 20.9%; p = 0.984).The donation service area(DSA) of a donor hospital explained 27.9% (p = 0.001) of the variability in whether a DCD liver was recovered.

CONCLUSION

A number of potentially high quality DCD donor livers go unrecovered each year, which may be partially explained by donor blood type and variation in regional and DSA level practice patterns.

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.

State-of-the-art surgery for hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is the most commonly diagnosed primary liver tumor with an increasing incidence worldwide. Management of patients with HCC is largely dictated by the presence of cirrhosis, disease stage, underlying liver function, and patient performance status.

PURPOSE

We provide an update on key aspects of surgical treatment options for patients with HCC. RESULTS & CONCLUSIONS: Liver resection and transplantation remain cornerstone treatment options for patients with early-stage disease and constitute the only potentially curative options for HCC. Selection of patients for surgical treatment should include a thorough evaluation of tumor characteristics and biology, as well as evidence-based use of various available treatment options to achieve optimal long-term outcomes for patients with HCC.

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

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

Long-Term Outcomes of Early Experience in Donation After Circulatory Death Liver Transplantation: Outcomes at 10 Years

BACKGROUND Donation after circulatory death (DCD) livers remain an underutilized pool of transplantable organs due to concerns of inferior long-term patient survival (PS) and graft survival (GS), which factors greatly into clinician decision-making and patient expectations. MATERIAL AND METHODS This retrospective study used SRTR data to assess 33 429 deceased-donor liver transplants (LT) and compared outcomes between DCD and donation after brain death (DBD) LT recipients in the United States. Data were collected from 2002 to 2008 to obtain 10 years of follow-up (2012-2018) in the era of MELD implementation. Propensity scores for donor type (DCD vs DBD) were estimated using logistic regression, and the association of donor type with 10-year outcomes was evaluated after adjustment using stabilized inverse probability of treatment weights. RESULTS After adjusting for confounders, patient survival for DBD recipients at 10 years was 60.7% versus 57.5% for DCD recipients (P=0.24). Incorporating retransplants, 10-year adjusted patient survival was 60.2% for DBD recipients versus 55.5% for DCD recipients (P=0.07). Adjusted 10-year graft survival for DBD recipients was 56.4% versus 45.4% for DCD recipients (P<0.001). Surprisingly, however, 1 year after LT, DBD and DCD graft failure rates converged to 7.5% over the remaining 9 years. CONCLUSIONS These data reveal inferior 10-year DCD graft survival, but only in the first year after LT, and similar 10-year patient survival in DCD LT recipients compared to DBD recipients. Our results show the stability and longevity of DCD grafts, which should encourage the increased utilization of these livers for transplantation.

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.

Expanding Role of Donation After Circulatory Death Donors in Liver Transplantation

Better understanding of how to utilize donation after circulatory death (DCD) liver grafts has resulted in improved national outcomes and expansion in the number of DCD liver transplants (LTs). This improvement has been driven by better donor and recipient matching, careful evaluation of hemodynamics during withdrawal of life support, and refinement of the procurement operation. Changes to liver allocation likely will result in increased utilization of DCD liver grafts. Ischemic cholangiopathy remains the Achilles heel of DCD LTs and, although rates have fallen with improved protocols, a certain rate likely is unavoidable. This review discusses contemporary issues with DCD LTs.

Differential Impact of Extended Criteria Donors After Brain Death or Circulatory Death in Adult Liver Transplantation

Using grafts from extended criteria donors (ECDs) and donation after circulatory death (DCD) donors is a strategy to address organ shortage in liver transplantation (LT). We studied the characteristics and outcomes of ECD and DCD grafts. We retrospectively studied consecutive adults who underwent deceased donor LT between 2006 and 2019. ECD was defined using modified Eurotransplant criteria. Our primary outcomes were graft and patient survival. A total of 798 grafts were used for LT, of which 93.1% were donation after brain death (DBD; 59.9% were also ECD) and 6.9% were DCD grafts (49.1% were also ECD). Among DBD graft recipients, donors having >33% liver steatosis or 3 ECD criteria resulted in poorer graft survival. Otherwise ECD graft recipients had similar graft and patient survival compared with non-ECD graft recipients. DCD graft recipients also had similar patient survival compared with DBD recipients. However, DCD grafts from an ECD appeared to have worse outcomes. DCD graft recipients experienced higher rates of early allograft dysfunction (50.9% versus 24.7%; P < 0.001) and ischemic biliopathy (16.4% versus 1.5%; P < 0.001) compared with DBD graft recipients. Use of DBD grafts from ECDs did not impact outcomes unless there was significant donor steatosis or 3 Eurotransplant criteria were met. DCD graft recipients have similar patient survival compared with DBD graft recipients as long as the donor was not an ECD. We recommend that DBD donors with 3 or more ECD features or >33% steatosis and DCD donors with any ECD features be used with caution in adult LT.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

Adequate donor pump flow during NRP was a protective.

Livers From Pediatric Donation After Circulatory Death Donors Represent a Viable and Underutilized Source of Allograft

Despite increased numbers of donation after circulatory death (DCD) donors, pediatric DCD livers are underused. To investigate possible reasons for this discrepancy, we conducted a retrospective cohort study using 2 data sets from the Organ Procurement and Transplantation Network for all deceased liver donors and for all recipients of DCD liver transplants from March 8, 1993, to June 30, 2018. Pediatric (0-12 years) and adolescent (13-17 years) DCD donors were compared with those aged 18-40 years. We found that pediatric DCD allografts are recovered at a significantly lower rate than from 18-to-40-year-old donors (27.3% versus 56.3%; P < 0.001). However, once recovered, these organs are transplanted at a similar rate to those from the 18-to-40-year-old donor cohort (74.7% versus 74.2%). Significantly more pediatric DCD livers (odds ratio [OR], 3.75; confidence interval [CI], 3.14-4.47) were not recovered compared with adult organs, which were most commonly not recovered due to organ quality (10.2% versus 7.1%; P < 0.001). The 10-year relative risks (RRs) for graft failure and patient death were similar between pediatric and adult DCD donors, with adolescent DCD livers demonstrating improved outcomes. DCD livers transplanted into pediatric donors were protective against graft failure (RR, 0.46; 95% confidence interval [CI], 0.21-0.99) and patient death (RR, 0.16; 95% CI, 0.04-0.69). In conclusion, despite lower rates of recovery, pediatric DCD livers represent a viable organ source for certain adults and children.

Microsteatosis in Livers From Donation After Circulatory Death Donors Is Associated With Inferior Outcomes Following Liver Transplantation

The acceptable threshold remains unknown for the percentage of macrosteatosis (MaS) and microsteatosis (MiS) to yield optimal outcomes after donation after circulatory death (DCD) liver transplantation (LT). The purpose of this analysis was to determine the impact of donor liver MaS and MiS on DCD LT outcomes. Using the Organ Procurement and Transplantation Network database, we analyzed pretransplant biopsy results from adult, solitary, DCD livers transplanted between January 1, 2006, and December 31, 2017. Kaplan-Meier analysis was used to assess graft and patient survival based on MaS and MiS severity. MiS was divided into the groups MiS ≤10% and >10%. MaS was divided into the groups MaS ≤15% and >15%. Of 7757 recovered DCD livers, 11.4% (n = 885) were biopsied and transplanted. Patients who received DCD livers with MaS >15% had significantly worse patient survival (P < 0.04), and those with MiS >10% demonstrated inferior graft and patient survival (P < 0.02). In multivariate analyses including known risk factors, both MaS >15% and MiS >10% were associated with increased risk of graft failure and patient mortality (P < 0.03). Recipient and donor age >60 years were also associated with increased risk of graft failure and patient death. This analysis demonstrates that MaS >15% and MiS >10% are additional risk factors for graft loss and patient mortality in DCD LT.

Review 1: Lung transplant-from donor selection to graft preparation

For various end-stage lung diseases, lung transplantation remains one of the only viable treatment options. While the demand for lung transplantation has steadily risen over the last few decades, the availability of donor grafts is limited, which have resulted in progressively longer waiting lists. In the early years of lung transplantation, only the 'ideal' donor grafts are considered for transplantation. Due to the donor shortages, there is ongoing discussion about the safe use of 'suboptimal' grafts to expand the donor pool. In this review, we will discuss the considerations around donor selection, donor-recipient matching, graft preparation and graft optimisation.

Hypothermic machine perfusion in liver transplantation

Dynamic preservation strategies are a promising option to improve graft quality before transplantation, and to extend preservation time for either logistic or treatment reasons. In contrast to normothermic oxygenated perfusion, which intends to mimic physiological conditions in the human body, with subsequent clinical application for up to 24 hrs, hypothermic perfusion is mainly used for a relatively short period with protection of mitochondria and subsequent reduction of oxidative injury upon implantation. The results from two randomized controlled trials, where recruitment has finished are expected this year. Both ex situ perfusion techniques are increasingly applied in clinical transplantation including recent reports on viability assessment, which could open the door for an increased liver utilization in the future.

Donor hepatectomy time influences ischemia-reperfusion injury of the biliary tree in donation after circulatory death liver transplantation

BACKGROUND

Donor hepatectomy time is associated with graft survival after liver transplantation. The aim of this study was to identify the impact of donor hepatectomy time on biliary injury during donation after circulatory death liver transplantation.

METHODS

First, bile duct biopsies of livers included in (pre)clinical machine perfusion research were analyzed. Secondly, of the same livers, bile samples were collected during normothermic machine perfusion. Lastly, a nationwide retrospective cohort study was performed including 273 adult patients undergoing donation after circulatory death liver transplantation between January 1, 2002 and January 1, 2017. Primary endpoint was development of non-anastomotic biliary strictures within 2 years of donation after circulatory death liver transplantation. Cox proportional-hazards regression analyses were used to assess the influence of hepatectomy time on the development of non-anastomotic biliary strictures.

RESULTS

Livers with severe histological bile duct injury had a higher median hepatectomy time (P = .03). During normothermic machine perfusion, livers with a hepatectomy time >50 minutes had lower biliary bicarbonate and bile pH levels. In the nationwide retrospective study, donor hepatectomy time was an independent risk factor for non-anastomotic biliary strictures after donation after circulatory death liver transplantation (Hazard Ratio 1.18 per 10 minutes increase, 95% Confidence Interval 1.06-1.30, P value = .002).

CONCLUSION

Donor hepatectomy time negatively influences histological bile duct injury before normothermic machine perfusion and bile composition during normothermic machine perfusion. Additionally, hepatectomy time is a significant independent risk factor for the development of non-anastomotic biliary strictures after donation after circulatory death liver transplantation.

Liver Transplantation from Voluntary Organ Donor System in China: A Comparison between DBD and DCD Liver Transplants

Background

In China, the cases of liver transplantation (LT) from donation after citizens' death have rose year by year since the citizen-based voluntary organ donor system was initiated in 2010. The objective of our research was to investigate the early postoperative and late long-term outcomes of LT from donation after brain death (DBD) and donation after circulatory death (DCD) according to the current organ donation system in China.

Methods

Sixty-two consecutive cases of LT from donation after citizens' death performed in our hospital between February 2012 and June 2017 were examined retrospectively for short- and long-term outcomes. These included 35 DCD LT and 27 DBD LT.

Result

Subsequent median follow-up time of 19 months and 1- and 3-year graft survival rates were comparative between the DBD group and the DCD group (81.5% and 66.7% versus 67.1% and 59.7%; P = 0.550), as were patient survival rates (85.2% and 68.7% versus 72.2% and 63.9%; P = 0.358). The duration of ICU stay of recipients was significantly shorter in the DBD group, in comparison with that of the DCD group (1 versus 3 days, P = 0.001). Severe complication incidence (≥grade III) after transplantation was identical among the DBD and DCD groups (48.1% versus 60%, P = 0.352). There was no significant difference in postoperative mortality between the DBD and DCD groups (3 of 27 cases versus 5 of 35 cases). Twenty-one grafts (33.8%) were lost and 18 recipients (29.0%) were dead till the time of follow-up. Malignancy recurrence was the most prevalent reason for patient death (38.8%). There was no significant difference in incidence of biliary stenosis between the DBD and DCD groups (5 of 27 cases versus 6 of 35 cases, P = 0.846).

Conclusion

Although the sample size was small to some extent, this single-center study first reported that LT from DCD donors showed similar short- and long-term outcomes with DBD donors and justified the widespread implementation of voluntary citizen-based deceased organ donation in China. However, the results should be verified with a multicenter larger study.

Outcomes of Donation After Circulatory Death Liver Grafts From Donors 50 Years or Older: A Multicenter Analysis

BACKGROUND

As the population in the United States continues to age, an increase in the number of potential donation after circulatory death (DCD) donors with advanced chronological age can be expected. The aim of this study was to analyze a multi-institutional experience in liver transplantation using DCD donors 50 years or older.

METHODS

All DCD liver transplant (LT) performed at Mayo Clinic Florida, Mayo Clinic Rochester, and Mayo Clinic Arizona from 2002 to 2016 were included. Recipients of DCD LT were divided into 2 groups: those with donors 50 years or older (N = 155) and those with donors younger than 50 years(N = 316).

RESULTS

Graft survival was similar between the DCD donors 50 years or older group and DCD donors younger than 50 group(P = 0.99). Graft survival at 1, 3, and 5 years was 87.0%, 75.6%, and 71.8% in the DCD donors 50 years or older group and 85.8%, 76.0%, and 70.4% in the DCD donors younger than 50 group.The rate of total biliary complications (32.3% vs 23.7%; P = 0.049) and of anastomotic strictures (16.1% vs 8.2%; P = 0.01) were higher in the DCD donors 50 years or older compared with the DCD donors younger than 50 group. No statistical significant difference in the rate of ischemic cholangiopathy (11.6% vs 7.6%; P = 0.15) was seen between the 2 groups. Due to homogeneous practice patterns at the involved institutions, additional Cox regression analysis using national data obtained from Scientific Registry of Transplant Recipients was used to evaluate predictors of graft failure in DCD donors 50 years or older. Significant predictors of graft failure included: a calculated Model for End-Stage Liver Disease score of 30 or higher (P < 0.001), mechanical ventilation at the time of transplant (P < 0.001), medical condition (in intensive care unit) (P = 0.002), and cold ischemia time (P < 0.001).

CONCLUSIONS

The present study demonstrates that acceptable graft and patient survival can be achieved with the usage of DCD LT with donors 50 years or older. Optimizing recipient selection criteria and minimizing cold ischemia time may further improve outcomes.

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.

Outcomes of Controlled Donation After Cardiac Death Compared With Donation After Brain Death in Liver Transplantation: A Systematic Review and Meta-analysis

BACKGROUND

Controlled donation after cardiac death (CDCD) is increasingly common for liver transplantation due to donor shortage. However, the outcomes, in terms of grafts and recipients, remain unclear. The current study is a systematic review and meta-analysis that compared CDCD with donation after brain death (DBD).

METHODS

We conducted an electronic search of MEDLINE, EMBASE, and the Cochrane Database (from January 2007 to May 2017). Studies reporting Maastricht category III or IV CDCD liver transplantation were screened for inclusion. We appraised studies using the Newcastle-Ottawa scale and meta-analyzed using a fixed or random effects model.

RESULTS

A total of 21 studies, with 12,035 patients, were included in data analysis. CDCD did not differ from DBD in patient survival (hazard ration: 1.20; 95% confidence interval [CI]: 0.98 to 1.47; P = .07), graft survival (hazard ratio: 1.24; 95% CI: 0.99 to 1.56; P = .06), primary nonfunction (odds ratio [OR]: 1.74; 95% CI: 1.00 to 3.03; P = .05), hepatic artery thrombosis (OR: 1.17; 95% CI: 0.78 to 1.74; P = .45). However, CDCD was associated with biliary complications (OR: 2.48; 95% CI: 2.05 to 3.00), retransplantation (OR: 2.54; 95% CI: 1.99 to 3.26), and peak alanine aminotransferase (weighted mean difference: 330.88; 95% CI: 259.88 to 401.87). A subgroup analysis that included only hepatitis C virus (HCV)-positive recipients showed no significant difference between CDCD and DBD in biliary complications (P = .16), retransplantion (P = .15), HCV recurrence (P = .20), and peak alanine aminotransferase (P = .06).

CONCLUSIONS

CDCD transplantation is the most viable alternative to DBD transplantation in the current critical shortage of liver organs. HCV infection may not be the inferior factor of postoperative outcomes and survival.

Expanding the donor pool: Donation after circulatory death and living liver donation do not compromise the results of liver transplantation

Because of the shortfall between the number of patients listed for liver transplantation (LT) and the available grafts, strategies to expand the donor pool have been developed. Donation after circulatory death (DCD) and living donor (LD) grafts are not universally used because of the concerns of graft failure, biliary complications, and donor risks. In order to overcome the barriers for the implementation of using all 3 types of grafts, we compared outcomes after LT of DCD, LD, and donation after brain death (DBD) grafts. Patients who received a LD, DCD, or DBD liver graft at the University of Toronto were included. Between January 2009 through April 2017, 1054 patients received a LT at our center. Of these, 77 patients received a DCD graft (DCD group); 271 received a LD graft (LD group); and 706 received a DBD graft (DBD group). Overall biliary complications were higher in the LD group (11.8%) compared with the DCD group (5.2%) and the DBD group (4.8%; P < 0.001). The 1-, 3-, and 5-year graft survival rates were similar between the groups with 88.3%, 83.2%, and 69.2% in the DCD group versus 92.6%, 85.4%, and 84.7% in the LD group versus 90.2%, 84.2%, and 79.9% in the DBD group (P = 0.24). Furthermore, the 1-, 3-, and 5-year patient survival was comparable, with 92.2%, 85.4%, and 71.6% in the DCD group versus 95.2%, 88.8%, and 88.8% in the LD group versus 93.1%, 87.5%, and 83% in the DBD group (P = 0.14). Multivariate Cox regression analysis revealed that the type of graft did not impact graft survival. In conclusion, DCD, LD, and DBD grafts have similar longterm graft survival rates. Increasing the use of LD and DCD grafts may improve access to LT without affecting graft survival rates. Liver Transplantation 24 779-789 2018 AASLD.

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

INTRODUCTION

Hepatitis 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.

METHODS

This 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.

RESULTS

The 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.

CONCLUSIONS

In 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.

The impact of transarterial chemoembolization induced complications on outcomes after liver transplantation: A propensity-matched study

BACKGROUND

Loco-regional complications of transarterial chemoembolization (TACE) may adversely affect technical aspects of the liver transplantation (LT). This study reviewed the impact of those complications on postoperative outcomes encompassing implications on graft selection.

METHODS

A retrospective, propensity score matching (1:1) analysis accounting for donor and recipient confounders was performed on a dataset of patients undergoing LT for hepatocellular carcinoma. Outcomes of patients who had TACE (TACE-group) were compared with those who did not (NoTACE-group).

RESULTS

A total of 57 matched pairs were analyzed. TACE achieved effective tumor control (Pre-TACE vs Post-TACE; Median: 44 mm [interquartile range: 43-50] vs 17 mm [0-36]; P = .002) on imaging follow-up. TACE group had, at the hepatectomy, higher incidence of ischemia-related complications (adhesions of the necrotic tumor, cholecystitis, and/or bile duct necrosis) (40.4% vs 10.5%; P = .001). Overall major post-LT complications rate (Dindo-Clavien ≥3) were similar (P = .134). Those in the TACE group with donors after circulatory death (DCD) had 4.6% 90-day mortality and 54.3% major complication rate compared to 6.9% and 77.3% (P = .380 and P = .112, respectively).

CONCLUSION

TACE was an effective bridging procedure that may complicate LT inducing ischemic-related complications; nevertheless, it has not shown repercussions on mortality or morbidity after the procedure, even using donors after circulatory death.

The Impact of Liver Graft Injury on Cancer Recurrence Posttransplantation

Liver transplantation is the most effective treatment for selected patients with hepatocellular carcinoma. However, cancer recurrence, posttransplantation, remains to be the critical issue that affects the long-term outcome of hepatocellular carcinoma recipients. In addition to tumor biology itself, increasing evidence demonstrates that acute-phase liver graft injury is a result of hepatic ischemia reperfusion injury (which is an inevitable consequence during liver transplantation) and may promote cancer recurrence at late phase posttransplantation. The liver grafts from living donors, donors after cardiac death, and steatotic donors have been considered as promising sources of organs for liver transplantation and are associated with high incidence of liver graft injury. The acute-phase liver graft injury will trigger a series of inflammatory cascades, which may not only activate the cell signaling pathways regulating the tumor cell invasion and migration but also mobilize the circulating progenitor and immune cells to facilitate tumor recurrence and metastasis. The injured liver graft may also provide the favorable microenvironment for tumor cell growth, migration, and invasion through the disturbance of microcirculatory barrier function, induction of hypoxia and angiogenesis. This review aims to summarize the latest findings about the role and mechanisms of liver graft injury resulted from hepatic ischemia reperfusion injury on tumor recurrence posttransplantation, both in clinical and animal cohorts.

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

BACKGROUND & AIM

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.

METHODS

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).

RESULTS

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).

CONCLUSION

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.

PROviding Better ACcess To ORgans: A comprehensive overview of organ-access initiatives from the ASTS PROACTOR Task Force

The American Society of Transplant Surgeons (ASTS) PROviding better Access To Organs (PROACTOR) Task Force was created to inform ongoing ASTS organ access efforts. Task force members were charged with comprehensively cataloguing current organ access activities and organizing them according to stakeholder type. This white paper summarizes the task force findings and makes recommendations for future ASTS organ access initiatives.

A Rodent Model of Cardiac Donation After Circulatory Death and Novel Biomarkers of Cardiac Viability During Ex Vivo Heart Perfusion

BACKGROUND

Organ donation after circulatory death (DCD) is increasingly being used as a means of addressing the organ supply/demand mismatch in solid organ transplantation. There is reluctance to use DCD hearts, due to an inability to precisely identify hearts that have suffered irreversible injury. We investigated novel biomarkers and clinically relevant endpoints across a spectrum of warm ischemic times, before and during ex vivo heart perfusion (EVHP), to identify features associated with a nonviable cardiac phenotype.

METHODS

Donor rats sustained a hypoxic cardiac arrest, followed by variable acirculatory standoff periods (DCD groups). Left ventricular function, histochemical injury, and differences in left ventricular gene expression were studied before, and during, EVHP.

RESULTS

As warm ischemic time exposure increased in DCD groups, fewer hearts were functional during EVHP, and ventricular function was increasingly impaired. Histochemical assessment identified severely injured hearts during EVHP. A novel gene expression signature identified severely injured hearts during EVHP (upregulation of c-Jun, 3.19 (2.84-3.60); P = 0.0014; HMOX-1, 3.87 (2.72-5.50); P = 0.0037; and Hsp90, 7.66 (6.32-9.27); P < 0.0001 in DCD20), and may be useful in identifying high-risk hearts at the point of harvest (Hsp90).

CONCLUSIONS

We demonstrate that our preclinical model recapitulates the cardio-respiratory decompensation observed in humans, and that EVHP appears necessary to unmask distinguishing features of severely injured DCD hearts. Furthermore, we outline a clinically relevant multimodal approach to assessing candidate DCD hearts. Novel mRNA signatures correlated with elevations in cardiac Troponin-I in severely injured hearts during EVHP, and may also detect injury at the point of harvest.

Post-transplant cholangiopathy: Classification, pathogenesis, and preventive strategies

Biliary complications are the most frequent cause of morbidity, re-transplantation, and even mortality after liver transplantation. In general, biliary leakage and anastomotic and non-anastomotic biliary strictures (NAS) can be recognized. There is no consensus on the exact definition of NAS and different names and criteria have been used in literature. We propose to use the term post-transplant cholangiopathy for the spectrum of abnormalities of large donor bile ducts, that includes NAS, but also intraductal casts and intrahepatic biloma formation, in the presence of a patent hepatic artery. Combinations of these manifestations of cholangiopathy are not infrequently found in the same liver and ischemia-reperfusion injury is generally considered the common underlying mechanism. Other factors that contribute to post-transplant cholangiopathy are biliary injury due to bile salt toxicity and immune-mediated injury. This review provides an overview of the various types of post-transplant cholangiopathy, the presumed pathogenesis, clinical implications, and preventive strategies.

Noneligible Donors as a Strategy to Decrease the Organ Shortage

Organ procurement organization (OPO) performance is generally evaluated by the number of organ procurement procedures divided by the number of eligible deaths (donation after brain death [DBD] donors aged <70 years), whereas the number of noneligible deaths (including donation after cardiac death donors and DBD donors aged >70 years) is not tracked. The present study aimed to investigate the variability in the proportion of noneligible liver donors by the 58 donor service areas (DSAs). Patients undergoing liver transplant (LT) between 2011 and 2015 were obtained from the United Network for Organ Sharing Standard Transplant Analysis and Research file. LTs from noneligible and eligible donors were compared. The proportion of noneligible liver donors by DSA varied significantly, ranging from 0% to 19.6% of total liver grafts used. In transplant programs, the proportion of noneligible liver donors used ranged from 0% to 35.3%. On linear regression there was no correlation between match Model for End-Stage Liver Disease score for programs in a given DSA and proportion of noneligible donors used from the corresponding DSA (p = 0.14). Noneligible donors remain an underutilized resource in many OPOs. Policy changes to begin tracking noneligible donors and learning from OPOs that have high noneligible donor usage are potential strategies to increase awareness and pursuit of these organs.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Long-term results after transplantation of pediatric liver grafts from donation after circulatory death donors

Background

Liver grafts from donation after circulatory death (DCD) donors are increasingly accepted as an extension of the organ pool for transplantation. There is little data on the outcome of liver transplantation with DCD grafts from a pediatric donor. The objective of this study was to assess the outcome of liver transplantation with pediatric DCD grafts and to compare this with the outcome after transplantation of livers from pediatric donation after brain death (DBD) donors.

Method

All transplantations performed with a liver from a pediatric donor (≤16 years) in the Netherlands between 2002 and 2015 were included. Patient survival, graft survival, and complication rates were compared between DCD and DBD liver transplantation.

Results

In total, 74 liver transplantations with pediatric grafts were performed; twenty (27%) DCD and 54 (73%) DBD. The median donor warm ischemia time (DWIT) was 24 min (range 15–43 min). Patient survival rate at 10 years was 78% for recipients of DCD grafts and 89% for DBD grafts (p = 0.32). Graft survival rate at 10 years was 65% in recipients of DCD versus 76% in DBD grafts (p = 0.20). If donor livers in this study would have been rejected for transplantation when the DWIT ≥30 min (n = 4), the 10-year graft survival rate would have been 81% after DCD transplantation. The rate of non-anastomotic biliary strictures was 5% in DCD and 4% in DBD grafts (p = 1.00). Other complication rates were also similar between both groups.

Conclusions

Transplantation of livers from pediatric DCD donors results in good long-term outcome especially when the DWIT is kept ≤30 min. Patient and graft survival rates are not significantly different between recipients of a pediatric DCD or DBD liver. Moreover, the incidence of non-anastomotic biliary strictures after transplantation of pediatric DCD livers is remarkably low.

Preliminary Single-Center Canadian Experience of Human Normothermic Ex Vivo Liver Perfusion: Results of a Clinical Trial

After extensive experimentation, outcomes of a first clinical normothermic machine perfusion (NMP) liver trial in the United Kingdom demonstrated feasibility and clear safety, with improved liver function compared with standard static cold storage (SCS). We present a preliminary single-center North American experience using identical NMP technology. Ten donor liver grafts were procured, four (40%) from donation after circulatory death (DCD), of which nine were transplanted. One liver did not proceed because of a technical failure with portal cannulation and was discarded. Transplanted NMP grafts were matched 1:3 with transplanted SCS livers. Median NMP was 11.5 h (range 3.3-22.5 h) with one DCD liver perfused for 22.5 h. All transplanted livers functioned, and serum transaminases, bilirubin, international normalized ratio, and lactate levels corrected in NMP recipients similarly to controls. Graft survival at 30 days (primary outcome) was not statistically different between groups on an intent-to-treat basis (p = 0.25). Intensive care and hospital stays were significantly more prolonged in the NMP group. This preliminary experience demonstrates feasibility as well as potential technical risks of NMP in a North American setting and highlights a need for larger, randomized studies.

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.

Comparison of longterm outcomes and quality of life in recipients of donation after cardiac death liver grafts with a propensity-matched cohort

The use of liver grafts from donation after cardiac death (DCD) has been limited due to the increased rate of graft failure, mostly related to ischemic cholangiopathy (IC). It is our hypothesis that longterm outcomes and quality of life (QOL) similar to patients undergoing liver transplantation (LT) with donation after brain death (DBD) can be achieved. Clinical outcomes of all patients undergoing DCD LT (n = 300) between 1998 and 2015 were compared with a propensity score-matched cohort of patients undergoing DBD LT (n = 300). Patients were contacted for a follow-up questionnaire and short-form (SF)-12 QOL Survey administration. Median follow-up was >5 years. Graft survival at 1-, 3-, and 5-years was 83.8%, 75.5%, and 70.1% in the DCD LT group and 88.4%, 80.3%, and 73.9% in the DBD LT group (P = 0.27). Patient survival at 1-, 3-, and 5-years was 92.3%, 86.1%, and 80.3% in the DCD LT group and 92.3%, 85.1%, and 79.5% in the DBD LT group (P = 0.81). IC developed in 11.7% and 2% of patients in the DCD LT group and DBD LT group, respectively (P < 0.001). DCD LT recipients who developed IC had inferior graft survival compared with both the DCD non-IC group (P < 0.001) and the DBD LT group (P < 0.001); no difference in graft survival was observed between the DCD non-IC group and the DBD LT group (P = 0.50). Physical and Mental Composite Scores on the SF-12 QOL questionnaire were similar between the DCD LT and DBD LT groups (44.0 versus 45.4; P = 0.34 and 51.9 versus 52.2; P = 0.83), respectively. Similar longterm survival and QOL scores can be achieved between DCD LT and DBD LT. Prevention of IC in DCD LT yields excellent graft and patient survival with virtually no difference compared with DBD LT. Liver Transplantation 23 342-351 2017 AASLD.

Liver grafts procured from donors after circulatory death have no increased risk of microthrombi formation

Microthrombi formation provoked by warm ischemia and vascular stasis is thought to increase the risk of nonanastomotic strictures (NAS) in liver grafts obtained by donation after circulatory death (DCD). Therefore, potentially harmful intraoperative thrombolytic therapy has been suggested as a preventive strategy against NAS. Here, we investigated whether there is histological evidence of microthrombi formation during graft preservation or directly after reperfusion in DCD livers and the development of NAS. Liver biopsies collected at different time points during graft preservation and after reperfusion were triple-stained with hematoxylin-eosin (H & E), von Willebrand factor VIII (VWF), and Fibrin Lendrum (FL) to evaluate the presence of microthrombi. In a first series of 282 sections obtained from multiple liver segments of discarded DCD grafts, microthrombi were only present in 1%-3% of the VWF stainings, without evidence of thrombus formation in paired H & E and FL stainings. Additionally, analysis of 132 sections obtained from matched, transplanted donation after brain death and DCD grafts showed no difference in microthrombi formation (11.3% versus 3.3% respectively; P = 0.082), and no relation to the development of NAS (P = 0.73). Furthermore, no microthrombi were present in perioperative biopsies in recipients who developed early hepatic artery thrombosis. Finally, the presence of microthrombi did not differ before or after additional flushing of the graft with preservation solution. In conclusion, the results of our study derogate from the hypothesis that DCD livers have an increased tendency to form microthrombi. It weakens the explanation that microthrombi formation is a main causal factor in the development of NAS in DCD and that recipients could benefit from intraoperative thrombolytic therapy to prevent NAS following liver transplantation. Liver Transplantation 22 1676-1687 2016 AASLD.

Mass Spectrometry Based Metabolomics Comparison of Liver Grafts from Donors after Circulatory Death (DCD) and Donors after Brain Death (DBD) Used in Human Orthotopic Liver Transplantation

Use of marginal liver grafts, especially those from donors after circulatory death (DCD), has been considered as a solution to organ shortage. Inferior outcomes have been attributed to donor warm ischaemic damage in these DCD organs. Here we sought to profile the metabolic mechanisms underpinning donor warm ischaemia. Non-targeted Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry metabolomics was applied to biopsies of liver grafts from donors after brain death (DBD; n = 27) and DCD (n = 10), both during static cold storage (T₁) as well as post-reperfusion (T₂). Furthermore 6 biopsies from DBD donors prior to the organ donation (T₀) were also profiled. Considering DBD and DCD together, significant metabolic differences were discovered between T₁ and T₂ (688 peaks) that were primarily related to amino acid metabolism, meanwhile T₀ biopsies grouped together with T₂, denoting the distinctively different metabolic activity of the perfused state. Major metabolic differences were discovered between DCD and DBD during cold-phase (T₁) primarily related to glucose, tryptophan and kynurenine metabolism, and in the post-reperfusion phase (T₂) related to amino acid and glutathione metabolism. We propose tryptophan/kynurenine and S-adenosylmethionine as possible biomarkers for the previously established higher graft failure of DCD livers, and conclude that the associated pathways should be targeted in more exhaustive and quantitative investigations.

A novel compartmentalised stent graft to isolate the perfusion of the abdominal organs

Donation after cardiac death has been adopted to address the critical shortage of donor organs for transplant. Recovery of these organs is hindered by low blood flow that leads to permanent organ injury. We propose a novel approach to isolate the perfusion of the abdominal organs from the systemic malperfusion of the dying donor. We reasoned that this design could improve blood flow to organs without open surgery, while respecting the ethical principle that cardiac stress not be increased during organ recovery. Conditions within the stent were analysed using a computational fluid dynamics (CFD) method and validated on two prototypes in vitro. The hydrodynamic pressure drop across the stent was measured as 0.14-0.22 mmHg, which is a negligible influence. Device placement studies were also conducted on swine model fluoroscopically. All these results demonstrated the feasibility of rapidly isolating the perfusion to abdominal organs using a compartmentalised stent graft design.