Project description:BackgroundDonation after circulatory death (DCD) with cardiopulmonary bypass for thoracoabdominal normothermic regional perfusion (TA-NRP) has led to increased use of donor hearts. Rejection rates and long-term survival outcomes are not known.MethodsA single-center retrospective cohort review of patients who underwent DCD heart transplantation from January 2020 to December 2023 was performed. Donor and recipient characteristics, operative characteristics, and posttransplantation outcomes were analyzed. Subgroup analysis comparing co-localized vs distant donors and recipients was performed. The primary end point was 1-year survival. Secondary end points included incidences of primary graft dysfunction (PGD), cardiac allograft vasculopathy (CAV), rejection rate, and overall mortality. Our TA-NRP protocol has remained the same, consisting of sternotomy, ligation of aortic arch vessels, establishment of cardiopulmonary bypass, reintubation, resuscitation of the heart, and cold static storage during transport.ResultsIn total, 32 recipients underwent DCD heart transplantation, including 26 isolated hearts, 3 heart-lungs, and 3 heart-kidneys. The median age was 56 years for recipients and 39 years for donors; 21 donors and recipients were co-localized, whereas 11 were distant. One-year survival was 100%. Two patients required mechanical circulatory support for PGD. Four patients experienced grade 2R acute cellular rejection. Five patients had grade 1 CAV at 1 year. On subgroup analysis, distant donors and recipients had longer warm (47 vs 30 minutes; P < .005) and cold (213 vs 76 minutes; P < .005) ischemia times, without any other differences.ConclusionsOutcomes after DCD heart transplantation using TA-NRP remain encouraging with acceptable rates of rejection, PGD, CAV, and survival at 1 year.
Project description:BackgroundDonation after circulatory death liver transplantation (DCD LT) is underused given historical outcomes fraught with ischemic cholangiopathy (IC). We aimed to assess 6-mo IC in LT from DCD via normothermic regional perfusion (NRP) compared with DCD via static cold storage (SCS).MethodsA retrospective review of adult Maastricht-III DCD liver donors and recipients at the University of Colorado Hospital from January 1, 2017, to August 27, 2024, was performed. The 6-mo IC rate was compared between NRP and SCS. Secondary outcomes included biochemical assessments of accepted versus declined NRP liver allografts and allograft and patient survival for NRP and SCS groups.ResultsOne hundred sixty-two DCD LTs (SCS = 79; NRP = 97) were performed and 150 recipients (SCS = 74; NRP = 86) reached 6-mo follow-up. Six-month IC was lower for NRP compared with SCS (1.2% versus 9.5%, P = 0.03). The Donor Risk Index (2.44 [2.02-2.82] versus 2.17 [1.97-2.30], P = 0.002) and UK DCD Risk Score (4.2 ± 2.9 versus 3.2 ± 2.3, P = 0.008) were higher for NRP versus SCS. The Liver Graft assessment Following Transplantation score was less for NRP compared with SCS (-3.3 versus -3.1, P < 0.05). There were several differences in median biochemical parameters during NRP between accepted and declined livers, including higher terminal biliary bicarbonate (22.7 [20.9-29.1] versus 10.8 [7.6-13.1] mEq/L, P = 0.004). There were no significant differences in 12-mo allograft or patient survival for NRP versus SCS.ConclusionsNRP is a disruptive innovation that improves the utilization of DCD livers. Despite higher-risk donor-recipient pairing for NRP compared with SCS, we demonstrate a decrease in IC for NRP. These data facilitate benchmarking of thoracoabdominal NRP DCD LT and support further protocol development.
Project description: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.
Project description:BackgroundA better understanding of the molecular events during liver normothermic machine perfusion (NMP) is warranted to develop a data-based approach for the identification of biomarkers representative of graft quality and posttransplant outcome. We analysed the dynamic transcriptional changes during NMP and linked them to clinical and biochemical parameters.Methods50 livers subjected to NMP for up to 24 h were enrolled. Bulk RNA sequencing was performed in serial biopsies collected pre and during NMP, and after reperfusion. Perfusate was sampled to monitor liver function. qPCR and immunohistochemistry were performed to validate findings. Molecular profiles were compared between transplanted and non-transplanted livers, and livers with and without early allograft dysfunction.FindingsPathways related to immune and cell stress responses, cell trafficking and cell regulation were activated during NMP, while cellular metabolism was downregulated over time. Anti-inflammatory responses and genes involved in tissue remodelling were induced at later time-points, suggesting a counter-response to the immediate damage. NMP strongly induced a gene signature associated with ischemia-reperfusion injury. A 7-gene signature corresponds with the benchmarking criteria for transplantation or discard at 6 h NMP (area under curve 0.99). CD274 gene expression (encoding programmed cell-death ligand-1) showed the highest predictive value. LEAP2 gene expression at 6 h NMP correlated with impaired graft function.InterpretationAssessment of gene expression markers could serve as a reliable tool to evaluate liver quality during NMP and predicts early graft function after transplantation.FundingThe research was supported by "In Memoriam Dr. Gabriel Salzner Stiftung", Tiroler Wissenschaftsfond, Jubiläumsfonds-Österreichische Nationalbank and MUI Start grant.
Project description:There are currently no molecular tools that can reliably predict post-transplant outcome of kidney grafts during normothermic machine perfusion (NMP). In this study we investigated whether the cellular responses of donor kidneys during NMP can predict post-transplant outcome via transcriptomic analyses. Snap-frozen biopsies of 28 kidneys were taken before and after 2-hour NMP. 6 kidneys were included for single nucleus RNA sequencing (snRNA-seq) and 22 were for quantitative real-time PCR (qPCR). snRNA-seq analyses revealed a total of 38,451 cells distributed in 11 distinct cell types. NMP induced an upregulation of genes for ATP production-related proteins, heat shock proteins (HSP), transporter proteins and proteins that prevent protein misfolding. These findings were confirmed by the qPCR analyses. We observed no significant gene differences between the delayed graft function (DGF) and non-DGF kidneys. However, after NMP, the expression of HSP was above average in 3 kidneys with primary non-function (PNF) and kidneys that experienced acute rejection in the first month after transplantation compared to well-functioning kidneys. Overall, this study demonstrates that 2-hour NMP impacts gene expression profiles of the majority of cell types of the kidney. It suggests that NMP may serve to predict kidney function post-transplantation by triggering differential gene expression patterns.
Project description:ObjectivesTo determine whether hearts reanimated with normothermic regional perfusion (NRP) have clinically detectable changes in function using echocardiography comparing the prearrest and post-NRP imaging. As heart transplantation from donation after circulatory death (DCD) continues to increase, preliminary results suggest outcomes comparable with donation after brain death. It is unknown whether the obligatory period of warm ischemia experienced during DCD withdrawal process causes immediate changes in cardiac allograft function following in situ reanimation.MethodsWe retrospectively reviewed and compared predonation with postreanimation echocardiographic findings in all DCD donors at our institution from January to October 2021. All DCD donor organs were reanimated with in situ thoracoabdominal NRP after circulatory death. Echocardiographic assessment included (1) 2-dimensional and speckle-tracking measures of chamber size and function; (2) ejection fraction; (3) fractional area change; and (4) global longitudinal strain.ResultsAltogether, 4 DCD heart donations were performed during the study period. Basic demographics and withdrawal ischemic time periods are reported. There were no changes in left ventricular ejection fraction and right ventricular fractional area change when comparing the predonation and the postreanimation echocardiogram. There was a minimal, nonstatistically significant decrease in left ventricular global longitudinal strain and right ventricular free-wall systolic strain in 3 of the 4 donors following reanimation.ConclusionsDCD cardiac allografts reanimated with NRP demonstrated no change in echocardiographic parameters used for a standard predonation donor heart evaluation. Findings suggest cardiac function of DCD allografts reanimated with thoracoabdominal NRP is not adversely impacted by limited period of warm ischemia following circulatory arrest.
Project description:Normothermic regional perfusion (NRP) has gained widespread adoption in multiple European countries. The aim of this study was to examine the influence of thoracoabdominal-NRP (TA-NRP) on the utilization and outcomes of liver, kidney, and pancreas transplantation in the United States.MethodsUsing the US national registry data between 2020 and 2021, donation after circulatory death (DCD) donors were separated into 2 groups: DCD with TA-NRP and without TA-NRP. There were 5234 DCD donors; among them 34 donors were with TA-NRP. After 1:4 propensity score matching, the utilization rates were compared between DCD with and without TA-NRP.ResultsAlthough the utilization rates of kidney and pancreas were comparable (P = 0.71 and P = 0.06, 94.1% versus 95.6% and 8.8% versus 2.2%, respectively), that of liver in DCD with TA-NRP was significantly higher (P < 0.001; 70.6% versus 39.0%). Among 24 liver transplantations, 62 kidney transplantations, and 3 pancreas transplantations from DCD with TA-NRP, there were 2 liver grafts and 1 kidney graft that failed within 1 y after transplantation.ConclusionsTA-NRP in the United States significantly increased the utilization rate of abdominal organs from DCD donors with comparable outcomes after transplantation. Increasing use of NRP may expand the donor pool without compromising transplant outcomes.
Project description:BackgroundNormothermic regional perfusion (NRP) and hypothermic-oxygenated-perfusion (HOPE), were both shown to improve outcomes after liver transplantation from donors after circulatory death (DCD). Comparative clinical and mechanistical studies are however lacking.MethodsA rodent model of NRP and HOPE, both in the donor, was developed. Following asystolic donor warm ischemia time (DWIT), the abdominal compartment was perfused either with a donor-blood-based-perfusate at 37 °C (NRP) or with oxygenated Belzer-MPS at 10 °C (donor-HOPE) for 2 h. Livers were then procured and underwent 5 h static cold storage (CS), followed by transplantation. Un-perfused and HOPE-treated DCD-livers (after CS) and healthy livers (DBD) with direct implantation after NRP served as controls. Endpoints included the entire spectrum of ischemia-reperfusion-injury.FindingsHealthy control livers (DBD) showed minimal signs of inflammation during 2 h NRP and achieved 100% posttransplant recipient survival. In contrast, DCD livers with 30 and 60 min DWIT suffered from greater mitochondrial injury and inflammation as measured by increased perfusate Lactate, FMN- and HMGB-1-levels with subsequent Toll-like-receptor activation during NRP. In contrast, donor-HOPE (instead of NRP) led to significantly less mitochondrial-complex-I-injury and inflammation. Results after donor-HOPE were comparable to ex-situ HOPE after CS. Most DCD-liver recipients survived when treated with one HOPE-technique (86%), compared to only 40% after NRP (p = 0.0053). Following a reduction of DWIT (15 min), DCD liver recipients achieved comparable survivals with NRP (80%).InterpretationHigh-risk DCD livers benefit more from HOPE-treatment, either immediately in the donor or after cold storage. Comparative prospective clinical studies are required to translate the results.FundingFunding was provided by the Swiss National Science Foundation (grant no: 32003B-140776/1, 3200B-153012/1, 320030-189055/1, and 31IC30-166909) and supported by University Careggi (grant no 32003B-140776/1) and the OTT (grant No.: DRGT641/2019, cod.prog. 19CT03) and the Max Planck Society. Work in the A.G. laboratory was partially supported by the NIH R01NS112381 and R21NS125466 grants.
Project description:Liver grafts from controlled donation after circulatory death (cDCD) donors have lower utilization rates due to inferior graft and patient survival rates, largely attributable to the increased incidence of ischemic cholangiopathy, when compared with grafts from brain dead donors (DBD). Normothermic regional perfusion (NRP) may improve the quality of cDCD livers to allow for expansion of the donor pool, helping to alleviate the shortage of transplantable grafts. A systematic review and metanalysis was conducted comparing NRP cDCD livers with both non-NRP cDCD livers and DBD livers. In comparison to non-NRP cDCD outcomes, NRP cDCD grafts had lower rates of ischemic cholangiopathy [RR = 0.23, 95% CI (0.11, 0.49), p = 0.0002], primary non-function [RR = 0.51, 95% CI (0.27, 0.97), p = 0.04], and recipient death [HR = 0.5, 95% CI (0.36, 0.69), p < 0.0001]. There was no difference in outcomes between NRP cDCD donation compared to DBD liver donation. In conclusion, NRP improved the quality of cDCD livers compared to their non-NRP counterparts. NRP cDCD livers had similar outcomes to DBD grafts. This provides further evidence supporting the continued use of NRP in cDCD liver transplantation and offers weight to proposals for its more widespread adoption.