Viability assessment of livers donated after circulatory determination of death during normothermic regional perfusion.

BACKGROUND: Abdominal normothermic regional perfusion (A-NRP) allows in-situ reperfusion and recovery of abdominal organs metabolism in donors after circulatory death (DCD). Besides improving liver transplantation outcomes, liver injury and function can be assessed during A-NRP. METHODS: To refine liver viability assessment during A-NRP, prospectively collected data of controlled DCD donors managed at our Institution between October 2019 and May 2022 were retrospectively analyzed. Baseline characteristics, procedural variables and A-NRP parameters of donors whose liver was successfully transplanted were compared to those of donors whose liver was discarded. RESULTS: Twenty-seven donors were included and in 20 (74%) the liver was accepted (positive outcome). No differences between study groups were observed concerning baseline characteristics and warm ischemia times (WIT). Initial lactate levels were positively correlated with functional WIT (r2 = 0.4, p = 0.04), whereas transaminase levels were not. Blood flow during A-NRP was comparable, whereas oxygen consumption (VO2 ) was significantly higher in the positive outcome group after 1 h. Time courses of lactate, AST and ALT were significantly different between study groups (p < 0.001). Donors whose liver was accepted showed faster lactate clearance, a difference which was amplified by normalizing lactate clearance to oxygen delivery (DO2 ) and VO2 . Lactate clearance was correlated to transaminase levels and DO2 -normalized lactate clearance was the parameter best discriminating between study groups. CONCLUSIONS: DO2 -normalized lactate clearance may represent an element of liver viability assessment during A-NRP.

Outcome of liver transplantation with grafts from brain-dead donors treated with dual hypothermic oxygenated machine perfusion, with particular reference to elderly donors.

Prompted by the utilization of extended criteria donors, dual hypothermic oxygenated machine perfusion (D-HOPE) was introduced in liver transplantation to improve preservation. When donors after neurological determination of death (DBD) are used, D-HOPE effect on graft outcomes is unclear. To assess D-HOPE value in this setting and to identify ideal scenarios for its use, data on primary adult liver transplant recipients from January 2014 to April 2021 were analyzed using inverse probability of treatment weighting, comparing outcomes of D-HOPE-treated grafts (n = 121) with those preserved by static cold storage (n = 723). End-ischemic D-HOPE was systematically applied since November 2017 based on donor and recipient characteristics and transplant logistics. D-HOPE use was associated with a significant reduction of early allograft failure (OR: 0.24; 0.83; p = .024), grade ≥3 complications (OR: 0.57; p = .046), comprehensive complication index (-7.20 points; p = .003), and improved patient and graft survival. These results were confirmed in the subset of elderly donors (>75-year-old). Although D-HOPE did not reduce the incidence of biliary complications, its use was associated with a reduced severity of ischemic cholangiopathy. In conclusion, D-HOPE improves postoperative outcomes and reduces early allograft loss in extended criteria DBD grafts.

Normothermic Regional Perfusion and Hypothermic Oxygenated Machine Perfusion for Livers Donated After Controlled Circulatory Death With Prolonged Warm Ischemia Time: A Matched Comparison With Livers From Brain-Dead Donors.

Prolonged warm ischemia time (WIT) has a negative prognostic value in liver transplantation (LT) using grafts procured after circulatory death (DCD). To assess the value of abdominal normothermic regional perfusion (A-NRP) associated with dual hypothermic oxygenated machine perfusion (D-HOPE) in controlled DCD LT, prospectively collected data on LTs performed between January 2016 and July 2021 were analyzed. Outcome of controlled DCD LTs performed using A-NRP + D-HOPE (n = 20) were compared to those performed with grafts procured after brain death (DBD) (n = 40), selected using propensity-score matching. DCD utilization rate was 59.5%. In the DCD group, median functional WIT, A-NRP and D-HOPE time was 43, 246, and 205 min, respectively. Early outcomes of DCD grafts recipients were comparable to those of matched DBD LTs. In DCD and DBD group, incidence of anastomotic biliary complications and ischemic cholangiopathy was 15% versus 22% (p = 0.73) and 5% versus 2% (p = 1), respectively. One-year patient and graft survival was 100% versus 95% (p = 0.18) and 90% versus 95% (p = 0.82). In conclusion, the association of A-NRP + D-HOPE in DCD LT with prolonged WIT allows achieving comparable outcomes to DBD LT.

Clinical assessment of liver metabolism during hypothermic oxygenated machine perfusion using microdialysis.

BACKGROUND: While growing evidence supports the use of hypothermic oxygenated machine perfusion (HOPE) in liver transplantation, its effects on liver metabolism are still incompletely understood. METHODS: To assess liver metabolism during HOPE using microdialysis (MD), we conducted an open-label, observational pilot study on 10 consecutive grafts treated with dual-HOPE (D-HOPE). Microdialysate and perfusate levels of glucose, lactate, pyruvate, glutamate, and flavin mononucleotide (FMN) were measured during back table preparation and D-HOPE and correlated to graft function and patient outcome. RESULTS: Median (IQR) MD and D-HOPE time was 228 (210, 245) and 116 (103, 143) min. Three grafts developed early allograft dysfunction (EAD), with one requiring retransplantation. During D-HOPE, MD glucose and lactate levels increased (ANOVA = 9.88 [p = 0.01] and 3.71 [p = 0.08]). Their 2nd-hour levels were higher in EAD group and positively correlated with L-GrAFT score. 2nd-hour MD glucose and lactate were also positively correlated with cold ischemia time, macrovesicular steatosis, weight gain during D-HOPE, and perfusate FMN. These correlations were not apparent when perfusate levels were considered. In contrast, MD FMN levels invariably dropped steeply after D-HOPE start, whereas perfusate FMN was higher in dysfunctioning grafts. CONCLUSION: MD glucose and lactate during D-HOPE are markers of hepatocellular injury and could represent additional elements of the viability assessment.

Switch from intravenous or intramuscular to subcutaneous hepatitis B immunoglobulin: effect on quality of life after liver transplantation.

BACKGROUND: Hepatitis B immunoglobulin (HBIG) therapy is available in intravenous (IV) or intra-muscular (IM) formulations. Recently, a subcutaneous (SC) formulation was introduced. This study evaluated changes in quality of life when liver transplant (LT) recipients were switched from IV or IM HBIG to the SC formulation. METHODS: This multicentre, observational study involved adults who had undergone LT at least 1 year prior to study entry. Quality of life was evaluated using the ITaLi-Q questionnaire, assessing the impact of HBIG therapy on daily activities and patient satisfaction, and the SF-36 Health Survey. Patients completed the questionnaires prior to switching from IV or IM HBIG to SC HBIG and 6 months later. RESULTS: Eighty-six patients were enrolled; before the switch, 68.6% were receiving IM HBIG and 31.4% IV HBIG. After 6 months, significant improvements in 7 of the 8 ITaLi-Q domains were found, particularly side effects, need for support to adhere to the therapy and satisfaction with the HBIG therapy. Significant improvements in several SF-36 domains were documented, including physical functioning, physical and emotional role limitations, pain, social functioning, physical and mental summary scores. CONCLUSIONS: The SC route of administration reduces side effects and their interference with daily life, ameliorates negative feelings, and increases patient autonomy.

Impact of viral eradication with sofosbuvir-based therapy on the outcome of post-transplant hepatitis C with severe fibrosis.

BACKGROUND & AIMS: Several studies have shown that new direct-acting antivirals maintain their efficacy in liver transplant (LT) recipients with severe hepatitis C virus (HCV) recurrence. We determined the clinical impact of sofosbuvir/ribavirin in LT through the changes in liver function and fibrosis state at 24 and 48 weeks after treatment. METHODS: Between June 2014 and July 2015, 126 patients (30 F3, 96 F4 Metavir stage) were enrolled to receive sofosbuvir + ribavirin (24 weeks, 118 patients) or sofosbuvir + simeprevir + ribavirin (12 weeks, 8 patients); treatment was initiated at a median time of 4.3 years from LT. Median follow-up after therapy completion was 461 days. RESULTS: All 30 F3 patients achieved a sustained virological response at week 24 after treatment (SVR24) and showed a distinct amelioration of the AST-to-platelet ratio index (APRI), FIB-4 and liver stiffness at elastography by week 24 post-therapy, which were maintained at week 48. Of the 96 F4 cirrhotic patients, 72 (75%) achieved SVR24 accompanied by significant improvement of liver function, which was maintained at week 48 (Child B-C 22% baseline, 11% week 24, 7% week 48); APRI, FIB-4 and liver stiffness further improved significantly between weeks 24 and 48 of follow-up. Among the 77 responders (27 F3, 50 F4) who underwent elastography at baseline and at the end of follow-up, 39 (50.6%; 18 F3, 21 F4) exhibited a regression in fibrosis stage. CONCLUSION: At about 1 year from the completion of successful sofosbuvir-based therapy, patients with post-LT HCV and severe fibrosis experienced a long-term liver function improvement accompanied by a regression of fibrosis stage in half of them.

Liver transplantation with an uncommon full right hemiliver graft after hydatid cysts resection: Case report and review of the literature.

Because of widespread organ shortage, the transplant community has been exploiting more and more so-called "extended criteria" donors. In this scenario, liver grafts harboring benign tumors or large cysts represent an infrequent but potentially valuable source of viable grafts. We depict a challenging case of liver transplantation performed using a graft harboring two large Echinococcus granulosus hydatid cysts in close proximity with the hilar plate and complicated by cystobiliary communication. Although liver transplantation using grafts with hydatid cyst has been rarely reported (three published cases), our case was peculiar as one of the cysts was located close to the hilum and was ruptured into the left hepatic duct. The graft was finally accepted taking into account the low risk profile of the recipient, the good quality and size of the remnant liver parenchyma, and only after complete resection of the cysts was achieved. Although the recipient had a complication due to biliary confluence necrosis, at 10-months follow-up he is in good health with normal hepatic function, and a graft that could have been otherwise discarded was successfully used. The decision process along with technical and management issues are discussed.

Stereotactic ablative radiation therapy prior to liver transplantation in hepatocellular carcinoma.

OBJECTIVE: Stereotactic ablative radiotherapy (SABR) is a safe treatment approach for hepatocellular carcinoma (HCC) with comparable effectiveness to other local therapies. Only scant information is available concerning the role of SABR prior to liver transplantation (LT) for HCC. We present a consecutive case series investigating the role of SABR as a bridge or downstaging option in HCC patients subsequently submitted to LT. MATERIALS AND METHODS: Between September 2012 and May 2014, 8 patients for a total of 13 lesions underwent SABR prior to LT. Inclusion criteria were a pathological or radiological diagnosis of HCC, lesion size ≤6 cm or lesion number ≤3 with a total diameter ≤6 cm, no extrahepatic metastases, Child-Pugh class A-B, ECOG performance status ≤1. Patients were prescribed 36-48 Gy in 3-5 fractions (8 Gy × 5 fractions or 16 Gy × 3 fractions), in 3-5 consecutive days according to clinical and dosimetric decision making. Radiological response was evaluated according to the modified Response Evaluation Criteria in Solid Tumors (mRECIST). Pathological response was assessed through the rate of tumor necrosis relative to the total tumor volume. Acute and late toxicities were scored using the National Cancer Institute Common Terminology Criteria for Adverse Events version 4 (CTCAE v 4.0). RESULTS: Among the 13 pathologically evaluated lesions, 8 (61.5 %) lesions had a complete response 2 (15.3 %) had a minimal pathological response and other 2 (15.3 %) showed stable disease. The remaining lesion had a significant pathological response. Maximum detected toxicity included a G2 GGT increase in two patients (at 1 and 3 months respectively). One patient developed a non-classic RILD with a fivefold increase in transaminase enzymes level and a shift in Child-Pugh category from B7 to C10 due to bilirubin increase. Only one modification in the surgical strategy was needed during LT. CONCLUSIONS: SABR proved to be a safe and effective local therapy prior to LT in HCC patients. Prospective controlled clinical trials are needed to evaluate its efficacy compared to other local therapies in this setting.

How Can Machine Perfusion Change the Paradigm of Liver Transplantation for Patients with Perihilar Cholangiocarcinoma?

Perihilar cholangiocarcinomas (pCCA) are rare yet aggressive tumors originating from the bile ducts. While surgery remains the mainstay of treatment, only a minority of patients are amenable to curative resection, and the prognosis of unresectable patients is dismal. The introduction of liver transplantation (LT) after neoadjuvant chemoradiation for unresectable pCCA in 1993 represented a major breakthrough, and it has been associated with 5-year survival rates consistently >50%. Despite these encouraging results, pCCA has remained a niche indication for LT, which is most likely due to the need for stringent candidate selection and the challenges in preoperative and surgical management. Machine perfusion (MP) has recently been reintroduced as an alternative to static cold storage to improve liver preservation from extended criteria donors. Aside from being associated with superior graft preservation, MP technology allows for the safe extension of preservation time and the testing of liver viability prior to implantation, which are characteristics that may be especially useful in the setting of LT for pCCA. This review summarizes current surgical strategies for pCCA treatment, with a focus on unmet needs that have contributed to the limited spread of LT for pCCA and how MP could be used in this setting, with a particular emphasis on the possibility of expanding the donor pool and improving transplant logistics.

How to Preserve Steatotic Liver Grafts for Transplantation.

Liver allograft steatosis is a significant risk factor for postoperative graft dysfunction and has been associated with inferior patient and graft survival, particularly in the case of moderate or severe macrovesicular steatosis. In recent years, the increasing incidence of obesity and fatty liver disease in the population has led to a higher proportion of steatotic liver grafts being used for transplantation, making the optimization of their preservation an urgent necessity. This review discusses the mechanisms behind the increased susceptibility of fatty livers to ischemia-reperfusion injury and provides an overview of the available strategies to improve their utilization for transplantation, with a focus on preclinical and clinical evidence supporting donor interventions, novel preservation solutions, and machine perfusion techniques.

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

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Hypothermic Oxygenated Machine Perfusion of Liver Grafts from Brain-Dead Donors.

Hypothermic oxygenated machine perfusion (HOPE) was introduced in liver transplantation (LT) to mitigate ischemia-reperfusion injury. Available clinical data mainly concern LT with donors after circulatory-determined death, whereas data on brain-dead donors (DBD) are scarce. To assess the impact of end-ischemic HOPE in DBD LT, data on primary adult LTs performed between March 2016 and June 2018 were analyzed. HOPE was used in selected cases of donor age >80 years, apparent severe graft steatosis, or ischemia time ≥10 hours. Outcomes of HOPE-treated cases were compared with those after static cold storage. Propensity score matching (1:2) and Bayesian model averaging were used to overcome selection bias. During the study period, 25 (8.5%) out of 294 grafts were treated with HOPE. After matching, HOPE was associated with a lower severe post-reperfusion syndrome (PRS) rate (4% versus 20%, p = 0.13) and stage 2-3 acute kidney injury (AKI) (16% versus 42%, p = 0.046). Furthermore, Bayesian model averaging showed lower transaminases peak and a lower early allograft dysfunction (EAD) rate after HOPE. A steeper decline in arterial graft resistance throughout perfusion was associated with lower EAD rate. HOPE determines a significant reduction of ischemia reperfusion injury in DBD LT.

Hypothermic Oxygenated Machine Perfusion for Liver Transplantation: An Initial Experience.

OBJECTIVES: Due to widespread exploitation of extended criteria donors, machine perfusion is emerging as an alternative to static cold storage for organ preservation. Hypothermic oxygenated machine perfusion has been associated with improved outcomes after liver transplant, both in laboratory and clinical settings. Here, we present our initial experience with hypothermic oxygenated machine perfusion, evaluating incidence of postreperfusion syndrome, early allograft dysfunction, and long-term biliary complications. MATERIALS AND METHODS: End-ischemic dual (hepatic artery and portal vein) hypothermic oxygenated machine perfusion was carried out for 150 to 200 minutes before organ implantation in 4 liver transplants considered at increased risk due to donor, recipient, or matching issues. RESULTS: No device malfunction occurred. Theatre logistics were minimally affected. Incidences of post-reperfusion syndrome and early allograft dysfunction were 25% and 50%. At 6-month follow-up, all patients were alive with normal hepatic function and no evidence of ischemic cholangiopathy. CONCLUSIONS: In our experience, hypothermic oxygenated machine perfusion appeared safe and logistically simple. Further studies are needed to assess the real value of this technique and to identify which subset of patients would benefit from its implementation.

Extracellular Vesicles from Human Liver Stem Cells Reduce Injury in an Ex Vivo Normothermic Hypoxic Rat Liver Perfusion Model.

BACKGROUND: The gold standard for organ preservation before transplantation is static cold storage, which is unable to fully protect suboptimal livers from ischemia/reperfusion injury. An emerging alternative is normothermic machine perfusion (NMP), which permits organ reconditioning. Here, we aimed to explore the feasibility of a pharmacological intervention on isolated rat livers by using a combination of NMP and human liver stem cells-derived extracellular vesicles (HLSC-EV). METHODS: We established an ex vivo murine model of NMP capable to maintain liver function despite an ongoing hypoxic injury induced by hemodilution. Livers were perfused for 4 hours without (control group, n = 10) or with HLSC-EV (treated group, n = 9). Bile production was quantified; perfusate samples were collected hourly to measure metabolic (pH, pO2, pCO2) and cytolysis parameters (AST, alanine aminotransferase, lactate dehydrogenase). At the end of perfusion, we assessed HLSC-EV engraftment by immunofluorescence, tissue injury by histology, apoptosis by terminal deoxynucleotidyl transferase dUTP nick-end labeling assay, tissue hypoxia-inducible factor 1-α, and transforming growth factor-beta 1 RNA expression by quantitative reverse transcription-polymerase chain reaction. RESULTS: During hypoxic NMP, livers were able to maintain homeostasis and produce bile. In the treated group, AST (P = 0.018) and lactate dehydrogenase (P = 0.032) levels were significantly lower than those of the control group at 3 hours of perfusion, and AST levels persisted lower at 4 hours (P = 0.003). By the end of NMP, HLSC-EV had been uptaken by hepatocytes, and EV treatment significantly reduced histological damage (P = 0.030), apoptosis (P = 0.049), and RNA overexpression of hypoxia-inducible factor 1-α (P < 0.0001) and transforming growth factor-beta 1 (P = 0.014). CONCLUSIONS: HLSC-EV treatment, even in a short-duration model, was feasible and effectively reduced liver injury during hypoxic NMP.