Assessment Of Graft Viability Research Articles

Graft repair during machine perfusion: a current overview of strategies.

With changing donor characteristics (advanced age, obesity), an increase in the use of extended criteria donor (ECD) livers in liver transplantation is seen. Machine perfusion allows graft viability assessment, but still many donor livers are considered nontransplantable. Besides being used as graft viability assessment tool, ex situ machine perfusion offers a platform for therapeutic strategies to ameliorate grafts prior to transplantation. This review describes the current landscape of graft repair during machine perfusion. Explored anti-inflammatory therapies, including inflammasome inhibitors, hemoabsorption, and cellular therapies mitigate the inflammatory response and improve hepatic function. Cholangiocyte organoids show promise in repairing the damaged biliary tree. Defatting during normothermic machine perfusion shows a reduction of steatosis and improved hepatobiliary function compared to nontreated livers. Uptake of RNA interference therapies during machine perfusion paves the way for an additional treatment modality. The possibility to repair injured donor livers during ex situ machine perfusion might increase the utilization of ECD-livers. Application of defatting agents is currently explored in clinical trials, whereas other therapeutics require further research or optimization before entering clinical research.

Ischemia-Induced Metabolic Patterns Associate With Kidney Function During Normothermic Kidney Perfusion, a Preclinical Study.

To investigate if ischemia alters donor kidney metabolism and whether these changes associate with organ function. An unmet need in kidney transplantation is the ability to predict post-transplant organ function before transplantation. Key to such viability testing is a profound understanding of the organ's complex biochemistry and how ischemia, inevitable during the transplantation process, influences this. First, metabolic changes in glucose, lactate and 20 amino acids induced by no, 1h of warm, or 22h of cold ischemia were investigated during 4h perfusion of pig kidneys with autologous whole blood (n=6/group), simulating the ischemia-reperfusion phase of transplantation. Next, we confirmed similar metabolic changes during normothermic preservation of pig (n=3/group; n=4 for cold ischemia) and discarded human kidneys (n=6) perfused with a red-blood cell based perfusate. At 2h of perfusion with autologous whole blood, abundances of 17/20 amino acids were significantly different between groups, reflecting the type of ischemia. Amino acid changes at 15 min and 2h of perfusion correlated with future kidney function during perfusion. Similar metabolic patterns were observed during perfusion preservation of pig and discarded human donor kidneys, suggesting an opportunity to assess kidney viability before transplantation. Perfusate metabolite changes during normothermic kidney perfusion represent a unique non-invasive opportunity to assess graft viability. These findings now need validation in transplant studies.

Current opinion: advances in machine perfusion and preservation of vascularized composite allografts - will time still matter?

A major hurdle hindering more widespread application of reconstructive transplantation is the very limited cold ischemia time (CIT) of vascularized composite allografts (VCAs). In this review, we discuss cutting edge machine perfusion protocols and preservation strategies to overcome this limitation. Several preclinical machine perfusion studies have demonstrated the multifactorial utility of this technology to extend preservation windows, assess graft viability prior to transplantation and salvage damaged tissue, yet there are currently no clinically approved machine perfusion protocols for reconstructive transplantation. Thus, machine perfusion remains an open challenge in VCA due to the complexity of the various tissue types. In addition, multiple other promising avenues to prolong preservation of composite allografts have emerged. These include cryopreservation, high subzero preservation, vitrification and nanowarming. Despite several studies demonstrating extended preservation windows, there are several limitations that must be overcome prior to clinical translation. As both machine perfusion and subzero preservation protocols have rapidly advanced in the past few years, special consideration should be given to their potential complementary utilization. Current and emerging machine perfusion and preservation technologies in VCA have great promise to transform the field of reconstructive transplantation, as every extra hour of CIT helps ease the complexities of the peri-transplant workflow. Amongst the many advantages, longer preservation windows may allow for elective procedures, improved matching, establishment of novel immunomodulatory protocols and global transport of grafts, ultimately enabling us the ability to offer this life changing procedure to more patients.

Upfront Normothermic Machine Perfusion for a Liver Graft with Severe Macrovesicular Steatosis: A Proof-of-Concept Case

Graft steatosis has been associated with inferior outcomes after liver transplantation. Given the rising prevalence of obesity and fatty liver disease, strategies allowing safe and successful utilization of fatty liver grafts are needed. Liver preservation by normothermic machine perfusion (NMP) allows reducing ischemia-reperfusion injury, extending preservation time and assessing graft viability prior to implantation into the recipient. NMP can be initiated at the donor hospital using a transportable device (referred to as upfront NMP or normothermic machine preservation) or after a period of cold ischemia (known as back-to-base). In this report, we present the case of a graft from an HCV-positive DBD donor with 70% macrovesicular steatosis, which was successfully preserved and transplanted using upfront NMP. This approach was key to minimize initial injury to the graft and allowed assessing its viability before transplantation, while improving transplant logistics. Upfront NMP represents a promising approach to enhance the transplantation of fatty liver grafts.

Bioreactors for engineering patient-specific tissue grafts

Bioreactors have the potential to advance the clinical application of cell-based therapies. Cell expansion bioreactors have been used commercially for therapeutic applications; however, bioreactor-based engineering of 3D tissue grafts remains challenging owing to the complexity of tissue architectures, cellular heterogeneity and the lack of non-invasive, tissue-specific biomarkers with which to assess graft viability and maturation. Consequently, only a few bioreactor-based start-up companies that engineer patient-specific tissue grafts have emerged. In this Review, we discuss patient-specific bioreactors that can be used to engineer skin, small-diameter arteries and musculoskeletal tissues. We evaluate the impact of precision manufacturing, including 3D bioprinting, automation and non-invasive sensing, on optimizing the biological, chemical and physical parameters of the bioreactors that are required for specific tissue regeneration. We discuss the commercially available tissue-engineering bioreactors and the potential of digital twins and automation, and we outline the scientific and regulatory pathways that must be followed to enable the translation of tissue-specificbioreactors to the clinic. Bioreactors enable the cultivation of mammalian cells in a closely monitored and controlled microenvironment. This Review discusses bioreactor technologies and closed-loop set-ups for producing patient-specific engineered-tissue grafts, including skin, small-diameter arteries and musculoskeletal tissues, with a particular focus on commercialization and regulatory considerations.

The role of normothermic machine perfusion (NMP) in the preservation of ex-vivo liver before transplantation: A review.

The discrepancy between the number of patients awaiting liver transplantation and the number of available donors has become a key issue in the transplant setting. There is a limited access to liver transplantation, as a result, it is increasingly dependent on the use of extended criteria donors (ECD) to increase the organ donor pool and address rising demand. However, there are still many unknown risks associated with the use of ECD, among which preservation before liver transplantation is important in determining whether patients would experience complications survive after liver transplantation. In contrast to traditional static cold preservation of donor livers, normothermic machine perfusion (NMP) may reduce preservation injury, improve graft viability, and potentially ex vivo assessment of graft viability before transplantation. Data seem to suggest that NMP can enhance the preservation of liver transplantation to some extent and improve the early outcome after transplantation. In this review, we provided an overview of NMP and its application in ex vivo liver preservation and pre-transplantation, and we summarized the data from current clinical trials of normothermic liver perfusion.

Application of polymerized porcine hemoglobin in the ex vivo normothermic machine perfusion of rat livers.

Background: In contrast to traditional static cold preservation of donor livers, normothermic machine perfusion (NMP) may reduce preservation injury, improve graft viability and potentially allows ex vivo assessment of graft viability before transplantation. The polymerized porcine hemoglobin is a kind of hemoglobin oxygen carrier prepared by crosslinking porcine hemoglobin by glutaraldehyde to form a polymer. The pPolyHb has been proved to have the ability of transporting oxygen which could repair the organ ischemia-reperfusion injury in rats. Objective: In order to evaluate the effectiveness of rat liver perfusion in vitro based on pPolyHb, we established the NMP system, optimized the perfusate basic formula and explored the optimal proportion of pPolyHb and basal perfusate. Methods: The liver was removed and perfused for 6h at 37°C. We compared the efficacy of liver perfusion with different ratios of pPolyHb. Subsequently, compared the perfusion effect using Krebs Henseleit solution and pPolyHb perfusate of the optimal proportion, and compared with the liver preserved with UW solution. At 0h, 1h, 3h and 6h after perfusion, appropriate samples were collected for blood gas analysis and liver injury indexes detection. Some tissue samples were collected for H&E staining and TUNEL staining to observe the morphology and detect the apoptosis rate of liver cells. And we used Western Blot test to detect the expression of Bcl-2 and Bax in the tissues. Results: According to the final results, the optimal addition ratio of pPolyHb was 24%. By comparing the values of Bcl-2/Bax, the apoptosis rate of pPolyHb group was significantly reduced. Under this ratio, the results of H&E staining and TUNEL staining showed that the liver morphology was well preserved without additional signs of hepatocyte ischemia, biliary tract injury, or hepatic sinusoid injury, and hepatocyte apoptosis was relatively mild. Conclusion: Through the above-mentioned study we show that within 6h of perfusion based on pPolyHb, liver physiological and biochemical activities may essentially be maintained in vitro. This study demonstrates that a pPolyHb-based perfusate is feasible for NMP of rat livers. This opens up a prospect for further research on NMP.

Novel strategies in liver graft preservation-The French perspective.

Given the increasing graft shortage, the transplant community is forced to use so called marginal liver grafts with a higher susceptibility to ischemia-reperfusion injury. This exposes the recipient to a higher risk of graft failure and post-transplant complications. While static cold storage remains the gold standard in low-risk transplant scenarios, dynamic preservation strategies may allow to improve outcomes after transplantation of marginal liver grafts. Two dynamic preservation strategies, end-ischemic hypothermic oxygenated perfusion (HOPE) and continuous normothermic machine perfusion (cNMP), have been evaluated in randomized clinical trials. The results show improved preservation of liver grafts after cNMP and reduction of post-transplant biliary complications after HOPE. In comparison to cNMP, HOPE has the advantage of requiring less logistics and expertise with the possibility to return to default static cold storage. Both strategies allow to assess graft viability prior to transplantation and may thus contribute to optimizing graft selection and reducing discard rates. The use of dynamic preservation is rapidly increasing in France and results from a national randomized trial on the use of HOPE in marginal grafts will soon be available. Future applications should focus on controlled donation after circulatory death liver grafts, split grafts and graft treatment during perfusion. The final aim of dynamic liver graft preservation is to improve post-transplant outcomes, increase the number of transplanted grafts and allow expansion of transplant indications.

P11.02: Application of Ex-vivo Normothermic Machine Perfusion To Assess Renal Allograft Viability Following Renal Vein Thrombosis

Background: Ex-vivo Normothermic Machine perfusion (NMP) has been shown to improve transplantation outcomes and assess the viability of discarded grafts. We report an application of NMP in assessing renal allograft viability in a case of renal vein thrombosis (RVT) following deceased renal transplantation in the immediate postoperative period. Method: A 44-year-old female patient of unknown cause chronic kidney disease, on maintenance haemodialysis since 2018, underwent a deceased donor renal transplant from a young adult male donor after negative virtual crossmatch with CIT of 7 hrs 8 min. She had a history of fistula failure on multiple occasions and one abortion; her pro-coagulant workup was negative. She was on peritoneal dialysis for the past year, and she had multiple anti-HLA antibody specificities in class I and II loci (highest MFI 9709). She received Induction ATG, tacrolimus, mycophenolate, and steroids. The surgical procedure required reconstruction of the right renal vein. Allograft function was immediate and good with nadir creatinine 1.0mg/ml on postoperative day 6. On day 7, she had rapid onset anuria. Ultrasonogram showed clots in the graft pelvis with flow reversal, and CT angiogram showed RVT. On surgical re-exploration, the graft was congested, and the renal vein had an occlusive thrombus. After explantation and thrombectomy, the graft was placed on the Organ AssistTM using a red cell-based perfusate. It was perfused for six hours to check for graft viability on which there was the restoration of blood flow as evidenced by improving vascular resistance (peak 3mmHg/ml/min dropping to 1.3mmHg/ml/min) and blood flow (20ml/min rising to 220ml/min) and stabilization of lactate levels with a good macroscopic appearance. However, there was persistent haemorrhagic urine output despite an adequate and steady increase in renal blood flow. Result: Despite demonstrating viability on NMP, the allograft could not be re-implanted due to haemorrhagic urine output on NMP, given the potential for bleeding and the hemodynamic instability in the recipient. The recipient was discharged on day 18 on dialysis. The allograft nephrectomy specimen showed isolated vascular acute T cell-mediated rejection- C4d negative with superimposed venous thrombosis. Conclusion: EVNMP can help decision making in complex situations where graft viability assessment is not readily apparent. Received Funding from PGIMER Chandigarh.

Indocyanine green clearance test in liver transplantation: defining cut-off levels for graft viability assessment during organ retrieval and for the prediction of post-transplant graft function recovery - the Liver Indocyanine Green (LivInG) Trial Study Protocol

IntroductionViability assessment of the graft is essential to lower the risk of liver transplantation (LT) failure and need for emergency retransplantation, however, this still relies mainly on surgeon’s experience. Post-LT...

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

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

Machine perfusion in liver transplantation

Although liver transplantation is a true success story, many patients still die awaiting an organ. The increasing need for liver grafts therefore remains an unsolved challenge to the transplant community. To address this, transplant donor criteria have been expanded and, for example, more liver grafts with significant steatosis or from donors with circulatory death are being used. These marginal grafts, however, carry an increased risk of graft-associated complications, such as primary nonfunction, delayed graft function, or late biliary injuries. Therefore, reliable assessment of graft viability before use is essential for further success. To achieve this, machine liver perfusion, a procedure developed more than 50 years ago but almost forgotten at the end of the last century, is again of great interest. We describe in this review the clinical most applied machine perfusion techniques, their mechanistic background, and a novel concept of combining immediate organ assessment during hypothermic oxygenated perfusion, followed by an extended phase of normothermic machine perfusion, with simultaneous ex situ treatment of the perfused liver. Such a new approach may allow the pool of usable livers to dramatically increase and improve outcomes for recipients.

Improving Fat Graft Retention with Micro/Nanobubbles in Vivo

PURPOSE: Fat grafting is one of the most popular procedures in plastic and reconstructive surgery.1 However, retention rates of transplanted fat remain variable, often rendering unpredictable outcomes in the long term. Inadequate tissue oxygenation during the transplant process is thought to play a major role in this variability.2 To that end, we sought to examine the implementation of oxygenated micro/nanobubbles (MNBs) during transplantation of lipoaspirate as a means of maintaining adequate tissue oxygenation and improving graft survival. MNBs are small gas bubbles (<100 µm) that are stable for hours and can be saturated with high amounts of oxygen.3 Furthermore, their negative charge and irregular surface characteristics make them an ideal agent for separation and decontamination of charged particulate matter.4 We hypothesize that MNBs will enhance lipoaspirate survival and establish themselves as an important adjunctive step to be incorporated into current fat grafting techniques. METHODS: Twelve 6-week-old Fox Chase SCID beige mice were used as hosts for transplanted human lipoaspirate. Lipoaspirate samples harvested from healthy human donors were washed with either an oxygenated MNB or saline solution prior to injection into the dorsum of the mice. To assess graft viability, explants were harvested at 4-, 8-, and 12-week intervals. Following harvest, grafts were weighed, and volumes were obtained using gas pycnometry. Immunohistochemistry was completed utilizing antibodies directed toward CD31, Perilipin, and CA-9 as surrogates for angiogenesis, adipogenesis, and hypoxia, respectively. Quantitative analysis of IHC images was performed via ImageJ. RESULTS: The grafts that were washed in the MNB solution were significantly greater by mass as early as 4 weeks (P < 0.01). Likewise, an analysis of variance (ANOVA) showed that MNB-washed explants had greater volumes across all time points (P < 0.05). While CD31 staining showed that vessel density was equivocal at each interval between experimental and control groups, perilipin staining showed significantly greater intensity in the MNB group at both 4 and 8 weeks. Moreover, CA-9 staining intensity in the MNB group was notably lower by 12 weeks compared with that in the control group. CONCLUSIONS: The utilization of MNBs, as a source of oxygen, in the wash step prior to transplant may be beneficial for improving graft survival. MNB-washed grafts displayed greater volumes and masses over 12 weeks compared with their control-group saline-washed counterpart. Furthermore, as evidenced by the surrogate markers in the IHC analysis, lipoaspirate samples subjected to the MNB-wash demonstrated improved de novo adipogenesis and less hypoxia. Taken together, these preliminary data reveal promising translatable implications for oxygenated MNBs in the future of fat grafting paradigms. REFERENCES: 1. Simonacci F, Bertozzi N, et al. Procedure, applications, and outcomes of autologous fat grafting. Ann Med Surg (Lond). 2017;20:49–60. 2. Khouri RK, Jr., Khouri RE, et al. Diffusion and perfusion: the keys to fat grafting. Plast Reconstr Surg Glob Open. 2014;2(9):e220. 3. Matsuki N, Ichiba S, et al. Blood oxygenation using microbubble suspensions. Eur Biophys J. 2012;41(6):571–578. 4. Sayadi LR, Ziegler ME, et al. Topical oxygen therapy & micro/nanobubbles: a new modality for tissue oxygen delivery. Int Wound J. 2018;15(3):363–374.

Heterogeneous indications and the need for viability assessment: An international survey on the use of machine perfusion in liver transplantation.

Although machine perfusion (MP) is being increasingly adopted in liver transplantation, indications, timing, and modality are debated. To investigate current indications for MP a web‐based Google Forms survey was launched in January 2021 and addressed to 127 experts in the field, identified among first and corresponding Authors of MP literature in the last 10 years. The survey presented 10 real‐life cases of donor–recipient matching, asking whether the liver would be accepted (Q1), whether MP would be used in that particular setting (Q2) and, if so, by which MP modality (Q3) and at what timing during preservation (Q4). Respondents could also comment on each case. The agreement was evaluated using Krippendorff's alpha coefficient. Answers from 39 (30.1%) participants disclosed significant heterogeneity in graft acceptance, MP indications, technique, and timing. Agreement between respondents was generally poor (Q1, α = 0.11; Q2, α = 0.14; Q3, α = 0.12, Q4, α = 0.11). Overall, respondents preferred hypothermic MP and an end‐ischemic approach in 56.3% and 81.1% of cases, respectively. A total of 18 (46.2%) participants considered only one MP approach, whereas 17 (43.6%) and 3 (7.7%) considered using alternatively 2 or 3 different techniques. Of 38 comments, 17 (44.7%) were about the use of MP for graft viability assessment before implantation. This survey shows considerable variability in MP indications, emphasizing the need to identify scenarios of optimal utilization for each technique. Viability assessment emerges as a fundamental need of transplant professionals when considering the use of MP.

Assessing Kidney Graft Viability and Its Cells Metabolism during Machine Perfusion.

Kidney transplantation is the golden treatment for end-stage renal disease. Static cold storage is currently considered the standard method of preservation, but dynamic techniques, such as machine perfusion (MP), have been shown to improve graft function, especially in kidneys donated by extended criteria donors and donation after circulatory death. With poor organ quality being a major reason for kidneys not being transplanted, an accurate, objective and reliable quality assessment during preservation could add value and support to clinicians’ decisions. MPs are emerging technologies with the potential to assess kidney graft viability and quality, both in the hypothermic and normothermic scenarios. The aim of this review is to summarize current tools for graft viability assessment using MP prior to implantation in relation to the ischemic damage.

In ovo culturing of turkey (Meleagris gallopavo) ovarian tissue to assess graft viability and maturation of prefollicular germ cells and follicles

Biobanking of turkey ovarian tissue appears to be the most cost-effective method for the long-term preservation of female genetics. However, to ensure the successful transplantation of biobanked ovarian tissue for breed or line revival, the transplantation and development of fresh ovarian tissue must be evaluated. To assess transplantability, ovaries from poults 1 to 15 days posthatch (dph) were cultured in ovo in chicken eggs for 6 d and compared with the equivalent fresh tissue. The viability of cultured ovarian tissue was evaluated visually, whereas the level of late-stage apoptosis was measured via the TUNEL assay. In addition, the diameter and density of prefollicular germ cells and follicles (primordial and primary) were measured to assess maturation. Results showed that all cultured grafts (74/74), on surviving chicken chorioallantoic membrane, were viable with low levels (0.8 ± 0.1%) of late-stage apoptosis. The diameter of prefollicular germ cells in cultured ovaries from poults at 5 and 7 dph were larger (P < 0.002) than that of their preculture counterparts but were not able to reach their in vivo size. No significant follicular growth was observed in ovaries cultured in ovo; however, prefollicular germ cell density was over 4-fold greater in ovaries cultured from 7 dph poults (81,030 ± 17,611/mm3) than in their in vivo counterpart (16,463 ± 6,805/mm3). Interestingly, cultured ovaries from all other ages displayed equal or lower (P ≤ 0.05) prefollicular germ cell densities than their in vivo counterparts. Cultured ovaries from poults at 5 and 7 dph also exhibited an increase (P ≤ 0.05) in follicle density compared with their preculture counterparts; whereas, cultured ovaries from 15 dph poults had decreased densities (P < 0.001) compared with their preculture counterparts. This study demonstrated that, although age of ovarian tissue cultured in ovo did not affect the overall viability, 7 dph ovaries appeared to have a better cellular morphology after culturing in ovo than other ages. In addition, we also demonstrated for the first time that avian follicles can form during tissue culturing in ovo.

Perfusate Analysis During Dual Hypothermic Oxygenated Machine Perfusion of Liver Grafts: Correlations With Donor Factors and Early Outcomes.

Liver graft viability assessment has long been considered a limit of hypothermic oxygenated machine perfusion (HOPE). Aim of this study was assessing correlations of easily available perfusate parameters (PP) (aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, glucose, lactate, and pH) with graft features and outcome. In the period October 2018-February 2020, perfusate samples were obtained every 30 minutes during 50 dual-HOPE (D-HOPE) procedures. Correlations of PP with graft factors, 90-day graft loss, early allograft dysfunction (EAD), L-GrAFT score, acute kidney injury, and comprehensive complication index were analyzed using Pearson coefficient, receiver-operating characteristics analysis and by univariable and multivariable regression. Median D-HOPE time was 122 minutes. All parameters were normalized to liver weight. Only macrovesicular steatosis (MaS) significantly impacted PP levels and slope. Grafts with ≥30% MaS exhibited significantly different PP values and slope. Graft loss and EAD rate were 2% (n = 1) and 26% (n = 13). All PP except lactate correlated with EAD, 90-minute alanine aminotransferase showing the highest area under the receiver-operating characteristics curve (0.84). However, at multivariable analysis, the only factor independently associated with EAD was MaS (odds ratio, 5.44; confidence interval, 1.05-28.21; P = 0.04). Ninety minutes lactate dehydrogenase had the strongest correlation with L-GrAFT (R = 0.70; P < 0.001). PP correlated poorly with comprehensive complication index and grades 2-3 acute kidney injury rate. PP were predictive of graft function after transplant, but their association with graft survival and clinical outcomes requires further evaluation. MaS influenced levels of PP and was the only independent predictor of EAD.

Bile Composition as a Diagnostic and Prognostic Tool in Liver Transplantation.

Bile secretion and composition reflects the functional status of hepatocytes and cholangiocytes. Bile composition can have a role in the assessment of donor grafts before implantation in the recipient. In addition, changes in bile composition after liver transplantation can serve as a diagnostic and prognostic tool to predict posttransplant complications, such as primary nonfunction, acute cellular rejection, or nonanastomotic biliary strictures. With the popularization of liver machine perfusion preservation in the clinical setting, there is a revisited interest in biliary biomarkers to assess graft viability before implantation. This review discusses current literature on biliary biomarkers that could predict or assess liver graft and bile duct viability. Bile composition offers an exciting and novel perspective in the search for reliable hepatocyte and cholangiocyte viability biomarkers.

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

BackgroundNormothermic 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 ReportsFrom 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.ConclusionsNMP provides a potential tool for preservation and assessment of ECD livers in China.

Evaluation of Plasma Disappearance Rate Indocyanine Green Clearance as a Predictor of Liver Graft Rejection in Donor Brain Death

IntroductionThere currently exist no quantitative methods to assess graft viability before the donor procurement procedure. In Europe, around 20% of liver grafts evaluated “in situ” by an experienced surgeon are discarded. The aim of this study is to evaluate the use of the plasma disappearance rate indocyanine green (PDR-ICG) clearance in predicting liver graft rejection to avoid this 20% of futile surgeries. ObjectivesTo evaluate PDR-ICG as a predictor of liver graft rejection in death brain donors compared with the gold standard evaluation by an experienced surgeon. Material and MethodsProspective observational single center study. From March 2017 to July 2019, 29 donors were included in the study, 17 were men and 12 women with a median age of 68 years ± 16.9 years. Donors had an intensive care unit stay of 2 days ± 4 days. PDR-ICG was measured with PICCO2 monitor. Indocyanine green clearance dose was 0.25 mg/kg injected intravenously in the operating room just before donor procurement procedure is initiated. The surgeon was unaware of the PDR-ICG measure until the decision of graft acceptance was taken. Data regarding the donors and biopsy results were included in a prospective database. ResultsPDR-ICG measure could be obtained in 10 minutes in all of the cases included. The median PDR-ICG obtained was 18%/min (range, 2.4-31%/min). Graft rejection took place in 15 out of the 29 donors. PDR-ICG value was less than 10%/min in 6 of these rejected grafts and less than 15%/min in 10 donors. All donor grafts with PDR-ICG <15% were discarded. The graft had been discarded in 5 donors with a PDR-ICG >15%. ConclusionsIn our study a plasma disappearance rate <10 would have identified the grafts that would be rejected, thus avoiding the displacement work and expense of the surgical team. These results should be confirmed in a multicentric study.