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

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. Keywords: ex situ organ perfusion; machine perfusion; normothermic regional perfusion; organ preservation; viability assessment

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

A multicentre outcome analysis to define global benchmarks for donation after circulatory death liver transplantation

BACKGROUND: To identify the best possible outcomes in liver transplantation from donation after circulatory death donors (DCD) and to propose outcome values, which serve as reference for individual liver recipients or patient groups. METHODS: Based on 2219 controlled DCD liver transplantations, collected from 17 centres in North America and Europe, we identified 1012 low-risk, primary, adult liver transplantations with a laboratory MELD of ≤20points, receiving a DCD liver with a total donor warm ischemia time of ≤30minutes and asystolic donor warm ischemia time of ≤15minutes. Clinically relevant outcomes were selected and complications were reported according to the Clavien-Dindo-Grading and the Comprehensive Complication Index (CCI). Corresponding benchmark cut-offs were based on median values of each centre, where the 75(th)-percentile was considered. RESULTS: Benchmark cases represented between 19.7% and 75% of DCD transplantations in participating centers. The one-year retransplant and mortality rate was 5.23% and 9.01%, respectively. Within the first year of follow-up, 51.1% of recipients developed at least one major complication (≥Clavien-Dindo-Grade-III). Benchmark cut-offs were ≤3days and ≤16days for ICU and hospital stay, ≤66% for severe recipient complications (≥Grade-III), ≤16.8% for ischemic cholangiopathy, and ≤38.9CCI points at one-year posttransplant. Comparisons with higher risk groups showed more complications and impaired graft survival, outside the benchmark cut-offs. Organ perfusion techniques reduced the complications to values below benchmark cut-offs, despite higher graft risk. CONCLUSIONS: Despite excellent 1-year survival, morbidity in benchmark cases remains high with more than half of recipients developing severe complications during 1-year follow-up. Benchmark cut-offs targeting morbidity parameters offer a valid tool to assess the protective value of new preservation technologies in higher risk groups, and provide a valid comparator cohort for future clinical trials. LAY SUMMARY: The best possible outcomes after liver transplantation of grafts donated after circulatory death (DCD) were defined using the concept of benchmarking. These were based on 2219 liver transplantations following controlled DCD donation in 17 centres worldwide. The following benchmark cut-offs for the most relevant outcome parameters were developed: ICU and hospital stay: ≤3 and ≤16 days; primary non function: ≤2.5%; renal replacement therapy: ≤9.6%; ischemic cholangiopathy: ≤16.8% and anastomotic strictures ≤28.4%. One-year graft loss and mortality were defined as ≤14.4% and 9.6%, respectively. Donor and recipient combinations with higher risk had significantly worse outcomes. The use of novel organ perfusion technology achieved similar, good results in this high-risk group with prolonged donor warm ischemia time, when compared to the benchmark cohort