Donation after cardiac death liver transplantation: Graft quality evaluation based on pretransplant liver biopsy

The short and long-term prognostic influences of liver grafts with high bilirubin levels at the time of organ recovery

BACKGROUND

Donors with hyperbilirubinemia are often not utilized for liver transplantation (LT) due to concerns about potential liver dysfunction and graft survival. The potential to mitigate organ shortages using such donors remains unclear.

METHODS

This study analyzed adult deceased donor data from the United Network for Organ Sharing database (2002-2022). Hyperbilirubinemia was categorized as high total bilirubin (3.0-5.0 mg/dL) and very high bilirubin (≥5.0 mg/dL) in brain-dead donors. We assessed the impact of donor hyperbilirubinemia on 3-month and 3-year graft survival, comparing these outcomes to donors after circulatory death (DCD).

RESULTS

Of 138 622 donors, 3452 (2.5%) had high bilirubin and 1999 (1.4%) had very high bilirubin levels. Utilization rates for normal, high, and very high bilirubin groups were 73.5%, 56.4%, and 29.2%, respectively. No significant differences were found in 3-month and 3-year graft survival between groups. Donors with high bilirubin had superior 3-year graft survival compared to DCD (hazard ratio .83, p = .02). Factors associated with inferior short-term graft survival included recipient medical condition in intensive care unit (ICU) and longer cold ischemic time; factors associated with inferior long-term graft survival included older donor age, recipient medical condition in ICU, older recipient age, and longer cold ischemic time. Donors with ≥10% macrosteatosis in the very high bilirubin group were also associated with worse 3-year graft survival (p = .04).

DISCUSSION

The study suggests that despite many grafts with hyperbilirubinemia being non-utilized, acceptable post-LT outcomes can be achieved using donors with hyperbilirubinemia. Careful selection may increase utilization and expand the donor pool without negatively affecting graft outcome.

Assessing Donor Liver Quality and Restoring Graft Function in the Era of Extended Criteria Donors

Liver transplantation (LT) is the final treatment option for patients with end-stage liver disease. The increasing donor shortage results in the wide usage of grafts from extended criteria donors across the world. Using such grafts is associated with the elevated incidences of post-transplant complications including initial nonfunction and ischemic biliary tract diseases, which significantly reduce recipient survival. Although several clinical factors have been demonstrated to impact donor liver quality, accurate, comprehensive, and effective assessment systems to guide decision-making for organ usage, restoration or discard are lacking. In addition, the development of biochemical technologies and bioinformatic analysis in recent years helps us better understand graft injury during the perioperative period and find potential ways to restore graft function. Moreover, such advances reveal the molecular profiles of grafts or perfusate that are susceptible to poor graft function and provide insight into finding novel biomarkers for graft quality assessment. Focusing on donors and grafts, we updated potential biomarkers in donor blood, liver tissue, or perfusates that predict graft quality following LT, and summarized strategies for restoring graft function in the era of extended criteria donors. In this review, we also discuss the advantages and drawbacks of these potential biomarkers and offer suggestions for future research.

Use of preprocurement biopsy in donation after circulatory death liver transplantation

We perform routine preprocurement image-guided percutaneous liver biopsies on potential donation after circulatory death (DCD) liver donors. The purpose of this study was to examine the impact of preprocurement liver biopsy on the use of livers from DCD donors. We retrospectively reviewed demographics, liver histology, and disposition of DCD liver donors within a single organ procurement organization (OPO) who underwent preprocurement liver biopsy from January 2000 through December 2019. A total of 212 potential donors underwent prerecovery biopsy. No donors were lost as a result of complications of biopsy. Of these, 183 (86.3%) had acceptable biopsies: 146 (79.8%) were successfully transplanted and 37 (20.2%) were deemed not suitable for transplant. In contrast, of 120 DCD livers recovered with the intent to transplant that were not biopsied prior to recovery, 59 (49.2%) were successfully transplanted, and 61 (50.8%) were deemed not suitable for transplant. A total of 14 donors were ruled out for transplant based on prerecovery histology. Successfully transplanted livers that underwent preprocurement biopsy were more likely to come from donors aged older than 50 years or with body mass index more than 30 kg/m² compared with successfully transplanted livers without a prerecovery biopsy. Biopsy excluded 6.6% of DCD donor livers for transplant prior to recovery and facilitated the successful recovery and transplant of two-thirds of potential DCD donor livers. Livers intended for transplant at the time of recovery that did not undergo preprocurement biopsy were more likely to not be recovered or to be discarded. Preprocurement biopsy provides additional histologic information prior to deploying resources and helps to identify usable livers that might otherwise be declined for transplant. Consideration of liver biopsy in this group benefits OPOs and transplant centers by maximizing organ use and optimizing resource deployment.

Antemortem Heparin in Organ Donation After Circulatory Death Determination: A Systematic Review of the Literature

Donation after circulatory death determination frequently involves antemortem heparin administration to mitigate peri-arrest microvascular thrombosis. We systematically reviewed the literature to: (1) describe heparin administration practices and (2) explore the effects on transplant outcomes. We searched MEDLINE and EMBASE for studies reporting donation after circulatory death determination heparin practices including use, dosage, and timing (objective 1). To explore associations between antemortem heparin and transplant outcomes (objective 2), we (1) summarized within-study comparisons and (2) used meta-regression analyses to examine associations between proportions of donors that received heparin and transplant outcomes. We assessed risk of bias using the Newcastle Ottawa Scale and applied the GRADE methodology to determine certainty in the evidence. For objective 1, among 55 eligible studies, 48 reported heparin administration to at least some donors (range: 15.8%-100%) at variable doses (up to 1000 units/kg) and times relative to withdrawal of life-sustaining therapy. For objective 2, 7 studies that directly compared liver transplants with and without antemortem heparin reported lower rates of primary nonfunction, hepatic artery thrombosis, graft failure at 5 y, or recipient mortality (low certainty of evidence). In contrast, meta-regression analysis of 32 liver transplant studies detected no associations between the proportion of donors that received heparin and rates of early allograft dysfunction, primary nonfunction, hepatic artery thrombosis, biliary ischemia, graft failure, retransplantation, or patient survival (very low certainty of evidence). In conclusion, antemortem heparin practices vary substantially with an uncertain effect on transplant outcomes. Given the controversies surrounding antemortem heparin, clinical trials may be warranted.

Development of the Eurotransplant Discard Risk Index to Predict Acceptance of Livers for Transplantation: A Retrospective Database Analysis

OBJECTIVES

The utilization of liver allografts could be optimized if nonacceptance is predicted. This study aimed to evaluate the prognostic ability of an updated Discard Risk Index in Eurotransplant.

MATERIALS AND METHODS

Potential deceased donors from January 2010 to December 2015 who had been reported to Eurotransplant were included in our analyses. Liver utilization was defined by transplant status as the primary outcome to evaluate the performance of the Eurotransplant-developed Discard Risk Index.

RESULTS

Of 11670 potential livers, 9565 (81%) were actually transplanted. Donor sex, age, history of diabetes, drug abuse, use of vasopressors, body mass index category, serum sodium, cause of death, donor type, and levels of C-reactive protein, bilirubin, aspartate and alanine aminotransferases, international normalized ratio, and gamma-glutamyltranspeptidase were associated with discard and combined in the Eurotransplant-developed Discard Risk Index. Correlation between the two Discard Risk Indexes was high (r = 0.86), and both achieved high C statistics of 0.72 and 0.75 (P < .001), respectively. Despite strong calibration, discard rates of 0.8% for overall donors and 6% of donors after circulatory death could be predicted with 80% accuracy.

CONCLUSIONS

The Eurotransplant-developed Discard Risk Index showed a high prognostic ability to predict liver utilization in a European setting. The model could therefore be valuable for identifying livers at high risk of not being transplanted in an early stage. These organs might profit the most from modified allocation strategies or advanced preservation techniques.

Recipient gender and body mass index are associated with early acute rejection in donation after cardiac death liver transplantation

BACKGROUND

Early acute rejection (EAR) is a common complication after liver transplantation (LT).

AIM

The aim of this study was to evaluate the incidence and risk factors of EAR in donation after cardiac death (DCD) liver transplantation recipients.

METHOD

We retrospectively analysed the data of 461 DCD liver transplants performed during the period from January 2010 to June 2016 to study the relationship between EAR and various clinical factors. EAR was defined as histologically proven acute cellular rejection occurring less than 90 days after transplantation.

RESULT

The median follow-up time for this study was 33.1 months (range: 0.03-92.8 months). Thirty-two (6.9%) patients developed EAR with a median period of 20.5 days (5-88 days) after transplantation. A multivariate analysis revealed that female recipient (hazard ratio: 2.801; P=0.024) and high recipient body mass index (BMI) (hazard ratio: 1.005; P=0.049) were two independent risk factors for early acute rejection.

CONCLUSIONS

In DCD liver transplantation, recipient female gender and high BMI were associated with a higher incidence of EAR, while the use of CD25-Ab and/or MMF had a protective effect.

Recommendations for Donor and Recipient Selection and Risk Prediction: Working Group Report From the ILTS Consensus Conference in DCD Liver Transplantation

Although the utilization of donation after circulatory death donors (DCDs) for liver transplantation (LT) has increased steadily, much controversy remains, and no common acceptance criteria exist with regard to donor and recipient risk factors and prediction models. A consensus conference was organized by International Liver Transplantation Society on January 31, 2020, in Venice, Italy, to review the current clinical practice worldwide regarding DCD-LT and to develop internationally accepted guidelines. The format of the conference was based on the grade system. International experts in this field were allocated to 6 working groups and prepared evidence-based recommendations to answer-specific questions considering the currently available literature. Working group members and conference attendees served as jury to edit and confirm the final recommendations presented at the end of the conference by each working group separately. This report presents the final statements and recommendations provided by working group 2, covering the entire spectrum of donor and recipient risk factors and prediction models in DCD-LT.

Severity of early allograft dysfunction following donation after circulatory death liver transplantation: a multicentre study

Background

Early allograft dysfunction (EAD) is associated with decreased graft and patient survival rates. This study aimed to identify the severity of EAD and develop a predictive model for EAD after donation after circulatory death (DCD) liver transplantation (LT). Furthermore, the influence of operative time on EAD incidence was also evaluated.

Methods

In this retrospective, multicentre cohort study, nomograms were established based on a single-centre training cohort (n=321) and validated in a 3-center validation cohort (n=501).

Results

The incidence rate of EAD was 46.4% (149/321) in the training cohort and 40.5% (203/501) in the validation cohort. Of the 149 EAD patients in the training cohort, 77 patients with either elevated alanine aminotransferase (ALT) or aspartate aminotransferase (AST) were classified as having EAD type A, and the rest of the EAD patients were classified as having EAD type B. Recipients with EAD type B had lower graft and patient survival rates than recipients with EAD type A (P=0.043 and 0.044, respectively). We further developed a nomogram to predict EAD (graft weight, cold ischemia time, donor age, model for end-stage liver disease (MELD) score) and another nomogram to predict EAD type B (graft weight, cold ischemia time, MELD score). The nomograms for the prediction of EAD and EAD type B had good discrimination [concordance index (C-index) =0.712 (0.666-0.758), 0.707 (0.641-0.773)] and calibration [Hosmer-Lemeshow (HL) P=0.384, P=0.425] in the validation cohort. An increased operative time (>6 h) was associated with increased EAD and EAD type B incidence in the high-risk group (P=0.005, P=0.020, respectively).

Conclusions

EAD type B was associated with decreased graft and patient survival rates. The novel nomograms effectively predicted the incidence of EAD and EAD type B in DCD LT patients.

Sequential Use of Normothermic Regional and Ex Situ Machine Perfusion in Donation After Circulatory Death Liver Transplant

In Italy, 20 minutes of a continuous flat line on an electrocardiogram are required for declaration of death. In the setting of donation after circulatory death (DCD), prolonged warm ischemia time prompted the introduction of abdominal normothermic regional perfusion (NRP) followed by postprocurement ex situ machine perfusion (MP). This is a retrospective review of DCD liver transplantations (LTs) performed at 2 centers using sequential NRP and ex situ MP. From January 2018 to April 2019, 34 DCD donors were evaluated. Three (8.8%) were discarded before NRP, and 11 (32.4%) were discarded based on NRP parameters (n = 1, 3.0%), liver macroscopic appearance at procurement and/or biopsy results (n = 9, 26.5%), or severe macroangiopathy at back-table evaluation (n = 1, 3.0%). A total of 20 grafts (58.8%; 11 uncontrolled DCDs, 9 controlled DCDs) were considered eligible for LT, procured and perfused ex situ (9 normothermic and 11 dual hypothermic MPs). In total, 18 (52.9%; 11 uncontrolled) livers were eventually transplanted. Median (interquartile range) no-flow time was 32.5 (30-39) minutes, whereas median functional warm ischemia time was 52.5 (47-74) minutes (controlled DCD), and median low-flow time was 112 minutes (105-129 minutes; uncontrolled DCD). There was no primary nonfunction, while postreperfusion syndrome occurred in 8 (44%) recipients. Early allograft dysfunction happened in 5 (28%) patients, while acute kidney injury occurred in 5 (28%). After a median follow-up of 15.1 (9.5-22.3) months, 1 case of ischemic-type biliary lesions and 1 patient death were reported. DCD LT is feasible even with the 20-minute no-touch rule. Strict NRP and ex situ MP selection criteria are needed to optimize postoperative results.

Protein Profiles of Pretransplant Grafts Predict Early Allograft Dysfunction After Liver Transplantation From Donation After Circulatory Death

BACKGROUND

Predicting the development of early allograft dysfunction (EAD) following liver transplantation (LT) remains challenging for transplant clinicians. The objectives of this study are to investigate the potential relationship between the protein profiles of pretransplant grafts and the onset of EAD, and then combine with clinical parameters to construct a mathematically predictive model.

METHODS

Clinical data of 121 LT procedures from donation after circulatory death at the authors' center were analyzed. The expression levels of 7 studied proteins were determined by immunohistochemistry. Another independent cohort of 37 subjects was designed for further validation of the predictive model.

RESULTS

With an incidence of 43.0% (52/121), EAD was linked to significantly increased risk of acute kidney injury and renal replacement therapy, as well as reduced 6-month patient and liver graft survival. Allograft weight and high intrahepatic vascular endothelial growth factor (VEGF) expression were identified as independent risk factors of EAD and survival outcomes. Liver grafts with high VEGF expression exhibited delayed functional recovery within the first postoperative week. The combination of VEGF overexpression and EAD yielded the highest frequency of renal dysfunction and the worst survival. Based on allograft weight and intrahepatic VEGF expression, an EAD risk assessment model was developed. The incidence of EAD differed significantly between grafts with risk scores ≥-1.72 and <-1.72. The model functioned well in the validation cohort.

CONCLUSIONS

Pretransplant intrahepatic protein profiling contributes to the estimation of early graft performance and recipient outcomes following LT. The predictive model could allow for an accurate prediction of EAD.

Perioperative and long-term outcomes of utilizing donation after circulatory death liver grafts with macrosteatosis: A multicenter analysis

BACKGROUND

Given the potentially additive risk from using donor livers that are both steatotic and from a donation after circulatory death (DCD) donor, there is a paucity of data on the outcome of DCD liver transplantation (LT) utilizing livers with macrosteatosis.

METHODS

All DCD LT performed at Mayo Clinic-Florida, Mayo Clinic-Arizona, and Mayo Clinic-Rochester from 1999 to 2019 were included (N = 714). Recipients of DCD LT were divided into 3 groups: those with moderate macrosteatosis (30%-60%), mild macrosteatosis (5%-30%), and no steatosis (<5%).

RESULTS

Patients with moderate macrosteatosis had a higher rate of postreperfusion syndrome (PRS; 53.9% vs 26.2%; P = .002), postreperfusion cardiac arrest (7.7% vs 0.3%; P < .001), primary nonfunction (PNF; 7.7% vs 1.0%; P = .003), early allograft dysfunction (EAD; 70.8% vs 45.6% and 8.3%; P = .02), and acute kidney injury (AKI; 39.1% vs 19.4%; P = .02) than patients with no steatosis. No difference in any of the perioperative complications was seen between the mild macrosteatosis and the no steatosis groups except for the rate of EAD (56.8% vs 45.6%; P = .04). No difference in ischemic cholangiopathy (IC), vascular thrombosis/stenosis or graft, and patient survival was seen between the 3 groups.

CONCLUSION

DCD donors with mild macrosteatosis < 30% can be utilized with no increase in perioperative complications and similar patient and graft survival compared to DCD donors with no steatosis. When utilizing DCD donors with moderate macrosteatosis higher rates of PRS, PNF, postreperfusion cardiac arrest, EAD, and AKI should be anticipated.

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.

First Preliminary Experience with Preservation of Liver Grafts from Extended-Criteria Donors by Normothermic Machine Perfusion in Asia

BACKGROUND Normothermic machine perfusion (NMP) can provide access to evaluate and resuscitate high-risk donor livers before transplantation. The purpose of this study was to determine the efficacy of NMP in preservation and assessment of extended-criteria donor (ECD) livers in China. CASE REPORT From September 2018 to March 2019, 4 liver grafts from 3 transplant center defined as ECD were subjected to NMP, and then were transplanted successfully. During perfusion, perfusion parameters such as vascular flow, glucose level, lactate clearance, and bile production/composition were recorded to assess graft viability. All recipients were followed up 6 months after transplantation. CONCLUSIONS NMP provides a potential tool for preservation and assessment of ECD livers in China.

The role of deceased donor liver biopsy: An analysis of 5449 liver transplant recipients

BACKGROUND

No standard exists for the use of deceased donor liver biopsy during procurement. We sought to evaluate liver biopsy and the impact of findings on outcomes and graft utilization.

METHODS

A prospective observational study of donors after neurologic determination of death was conducted from 02/2012-08/2017 (16 OPOs). Donor data were collected through the UNOS Donor Management Goals Registry Web Portal and linked to the Scientific Registry of Transplant Recipients (SRTR) for recipient outcomes. Recipients of biopsied donor livers (BxDL) were studied and a Cox proportional hazard analysis was used to identify independent predictors of 1-year graft survival.

RESULTS

Data from 5449 liver transplant recipients were analyzed, of which 1791(33%) received a BxDL. There was no difference in graft or patient survival between the non-BxDL and BxDL recipient groups. On adjusted analysis of BxDL recipients, macrosteatosis (21%-30%[n = 148] and >30%[n = 92]) was not found to predict 1-year graft survival, whereas increasing donor age (HR1.02), donor Hispanic ethnicity (HR1.62), donor INR (HR1.18), and recipient life support (HR2.29) were.

CONCLUSIONS

Excellent graft and patient survival can be achieved in recipients of BxDL grafts. Notably, as demonstrated by the lack of effect of macrosteatosis on survival, donor to recipient matching may contribute to these outcomes.

Use of Steatotic Grafts in Liver Transplantation: Current Status

In the field of liver transplantation, the demand for adequate allografts greatly exceeds the supply. Therefore, expanding the donor pool to match the growing demand is mandatory. The present review summarizes current knowledge of the pathophysiology of ischemia/reperfusion injury in steatotic grafts, together with recent pharmacological approaches aimed at maximizing the utilization of these livers for transplantation. We also describe the preclinical models currently available to understand the molecular mechanisms controlling graft viability in this specific type of donor, critically discussing the heterogeneity in animal models, surgical methodology, and therapeutic interventions. This lack of common approaches and interventions makes it difficult to establish the pathways involved and the relevance of isolated discoveries, as well as their transferability to clinical practice. Finally, we discuss how new therapeutic strategies developed from experimental studies are promising but that further studies are warranted to translate them to the bedside.

Assessment of Liver Graft Steatosis: Where Do We Stand?

The growing number of patients on waiting lists for liver transplantation and the shortage of organs have forced many centers to adopt extended criteria for graft selection, moving the limit of acceptance for marginal livers. Steatotic grafts that were, in the past, considered strictly unacceptable for transplantation because of the high risk of early nonfunction are now considered as a potential resource for organ implementation. Several methods to diagnose, measure, classify, and stage steatosis exist, but none can be considered qualitatively and quantitatively "the ideal method" to date. Clinical, biological, and imaging data can be very helpful to estimate graft steatosis, but histology still remains the gold standard. There is an increasing need for rapid and reliable tools to assess graft steatosis. Herein, we present a comprehensive review of the approaches that are currently used to quantify steatosis in liver grafts.

Normothermic ex-vivo liver perfusion: where do we stand and where to reach?

Nowadays liver transplantation is considered as the treatment of choice, however, the scarcity of suitable donor organs limits the delivery of care to the end-stage liver disease patients leading to the death while on the waiting list. The advent of ex-situ normothermic machine perfusion (NMP) has emerged as an alternative to the standard organ preservation technique, static cold storage (SCS). The newer technique promises to not only restore the normal metabolic activity but also attempt to recondition the marginal livers back to the pristine state, which are otherwise more susceptible to ischemic injury and foster the poor post-transplant outcomes. Areas covered: An extensive search of all the published literature describing the role of NMP based device in liver transplantation as an alternative to SCS was made on MEDLINE, EMBASE, Cochrane, BIOSIS, Crossref, Scopus databases and clinical trial registry on 10 May 2018. Expert commentary: The main tenet of NMP is the establishment of the physiological milieu, which permits aerobic metabolism to continue through out the period of preservation and limits the effects of ischemia-reperfusion (I/R) injury. In addition, by assessing the various metabolic and synthetic parameters the viability and suitability of donor livers for transplantation can be determined. This important technological advancement has scored satisfactorily on the safety and efficacy parameters in preliminary clinical studies. The present review suggests that NMP can offer the opportunity to assess and safely utilize the marginal donor livers if deemed appropriate for the transplantation. However, ongoing trials will determine its full potential and further adoption.

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.

Multiparametric functional magnetic resonance imaging for evaluation of hepatic warm ischemia-reperfusion injury in a rabbit model

BACKGROUND

To assess the feasibility of noninvasive and quantitative evaluation of hepatic pathophysiological changes in rabbit hepatic warm ischemia-reperfusion injury (WIRI) models by using intravoxel incoherent motion (IVIM), diffusion tensor imaging (DTI) and blood oxygen level dependent (BOLD) MRI.

METHODS

Twenty rabbits were randomly divided into hepatic WIRI model group and sham-operation group (n = 10 for each group). Hepatic WIRI was induced in rabbit by occluding hepatic inflow for 30 min and reperfusion for 6 h. The control group only underwent laparotomy and liver ligament dissection. IVIM with 11 b values (0 to 800 s/mm²), DTI with 2 b values (0 and 500 s/mm²) on 12 diffusion directions, and BOLD MRI with 9 TE (2.57 to 24.25 ms) were performed at 3 T clinical MR scanner. Rabbits were sacrificed for biochemical and histopathological analysis after MR scanning. All of functional MR, biochemical and histopathological parameters were analyzed by independent sample t test, Mann-Whitney U test, Pearson and Spearman correlation methods.

RESULTS

All of MR parameters showed moderate to excellent interobserver reproducibility. True diffusion (Dslow), pseudodiffusion (Dfast), perfusion fraction (PF), and mean diffusitivity (MD) were lower in WIRI models than in control rabbits (P < 0.01), R2* was higher in WIRI models than in control rabbits (P < 0.001), while fractional anisotropy (FA) showed no statistical difference. There were significant differences in I score and all of biochemical parameters between the two groups (P < 0.01). Functional MR parameters corresponded well with all of biochemical parameters and some of histopathological parameters (P < 0.05). Histopathological analysis showed the structure and morphology of hepatic lobule was normal and clear in control rabbits, while diffuse hepatocyte swelling, central vein and sinusoids congestion, and inflammatory cell infiltration in WIRI models.

CONCLUSIONS

IVIM, DTI, and BOLD MRI are noninvasive and useful techniques for assessing the microenvironment changes of hepatic WIRI in rabbit models.

Liver transplant outcomes using ideal donation after circulatory death livers are superior to using older donation after brain death donor livers

Multiple reports have demonstrated that liver transplantation following donation after circulatory death (DCD) is associated with poorer outcomes when compared with liver transplantation from donation after brain death (DBD) donors. We hypothesized that carefully selected, underutilized DCD livers recovered from younger donors have excellent outcomes. We performed a retrospective study of the United Network for Organ Sharing database to determine graft survivals for patients who received liver transplants from DBD donors of age ≥ 60 years, DBD donors < 60 years, and DCD donors < 50 years of age. Between January 2002 and December 2014, 52,271 liver transplants were performed in the United States. Of these, 41,181 (78.8%) underwent transplantation with livers from DBD donors of age < 60 years, 8905 (17.0%) from DBD donors ≥ 60 years old, and 2195 (4.2%) livers from DCD donors < 50 years of age. DCD livers of age < 50 years with < 6 hours of cold ischemia time (CIT) had superior graft survival when compared with DBD livers ≥ age 60 years (P < 0.001). In 2014, there were 133 discarded DCD livers; of these, 111 (83.4%) were from donors < age 50 years old. Young DCD donor livers (age < 50 years old) with short CITs yield results better than that seen with DBD livers > 60 years old. Careful donor organ and recipient selection can lead to excellent results, despite previous reports suggesting otherwise. Increased acceptance of these DCD livers would lead to shorter wait list times and increased national liver transplant rates. Liver Transplantation 22 1197-1204 2016 AASLD.