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The Journal of Thoracic and... Jun 2021Ex vivo lung perfusion provides an innovative method to assess and repair donor lungs. The current Toronto ex vivo lung perfusion protocol can reliably and...
OBJECTIVES
Ex vivo lung perfusion provides an innovative method to assess and repair donor lungs. The current Toronto ex vivo lung perfusion protocol can reliably and reproducibly preserve lungs for 12 hours. A longer ex vivo lung perfusion preservation time could enable the application of more advanced repair therapies and the rescue of more donor lungs for lung transplant. Our objective was to achieve stable 24-hour normothermic ex vivo lung perfusion.
METHODS
We systematically examined 3 modifications of ex vivo lung perfusion perfusate administration in a large animal 24-hour ex vivo lung perfusion model. Pig lungs were assigned to 4 groups (n = 5 per group): (1) control; (2) continuous replacement of ex vivo lung perfusion perfusate; (3) modified feed, which used a modified solution to maintain perfusate osmolality by adjusting glucose and sodium levels; and (4) total parenteral nutrition, in which we added parenteral nutrition to the perfusate.
RESULTS
Only 1 lung in the control group completed 24-hour ex vivo lung perfusion. However, 24-hour perfusion was achieved in 4 lungs in the continuous replacement group, 3 lungs in the modified feed group, and 4 lungs in the total parenteral nutrition group. The total parenteral nutrition group achieved significantly longer stable perfusion time compared with control (P = .03). Lung function was significantly improved and inflammatory cytokine production was reduced in the continuous replacement and total parenteral nutrition groups compared with control.
CONCLUSIONS
Modifications of ex vivo lung perfusion perfusate toward achieving a stable homeostatic state can extend perfusion time for up to 24 hours. Although these modifications allow for prolonged ex vivo lung perfusion, further research will be required to develop stable lung support beyond 24 hours.
Topics: Animals; Homeostasis; Lung; Lung Transplantation; Male; Organ Preservation; Parenteral Nutrition, Total; Perfusion; Swine; Transplants
PubMed: 32958268
DOI: 10.1016/j.jtcvs.2020.07.104 -
Minerva Anestesiologica Feb 2018This review focuses on recent developments in preservation techniques in liver transplantation. First, we discuss mechanisms of organ injury when using high-risk organs,... (Review)
Review
This review focuses on recent developments in preservation techniques in liver transplantation. First, we discuss mechanisms of organ injury when using high-risk organs, including donation after circulatory death and steatotic grafts and we summarize pathways of ischemia reperfusion injury together with their link to the immune response. Second, we report on improvement strategies of marginal liver grafts by different machine perfusion concepts and summarize perfusion approaches with recent clinical implementation.
Topics: Humans; Liver Transplantation; Perfusion; Postoperative Complications; Preoperative Care
PubMed: 28726360
DOI: 10.23736/S0375-9393.17.12016-X -
American Journal of Transplantation :... Apr 2019Ex vivo lung perfusion (EVLP) shows promise in ameliorating pretransplant acute lung injury (ALI) and expanding the donor organ pool, but the mechanisms of ex vivo...
Ex vivo lung perfusion (EVLP) shows promise in ameliorating pretransplant acute lung injury (ALI) and expanding the donor organ pool, but the mechanisms of ex vivo repair remain poorly understood. We aimed to assess the utility of gene expression for characterizing ALI during EVLP. One hundred sixty-nine porcine lung samples were collected in vivo (n = 25), after 0 (n = 11) and 12 (n = 11) hours of cold static preservation (CSP), and after 0 (n = 57), 6 (n = 8), and 12 (n = 57) hours of EVLP, utilizing various ventilation and perfusate strategies. The expression of 53 previously described ALI-related genes was measured and correlated with function and histology. Twenty-eight genes were significantly upregulated and 6 genes downregulated after 12 hours of EVLP. Aggregate gene sets demonstrated differential expression with EVLP (P < .001) but not CSP. Upregulated 28-gene set expression peaked after 6 hours of EVLP, whereas downregulated 6-gene set expression continued to decline after 12 hours. Cellular perfusates demonstrated a greater reduction in downregulated 6-gene set expression vs acellular perfusate (P < .038). Gene set expression correlated with relevant functional and histologic parameters, including P/F ratio (P < .001) and interstitial inflammation (P < .005). Further studies with posttransplant results are warranted to evaluate the clinical significance of this novel molecular approach for assessing organ quality during EVLP.
Topics: Animals; Biopsy; Feasibility Studies; Gene Expression Profiling; Gene Expression Regulation; In Vitro Techniques; Lung; Organ Preservation; Perfusion; Swine
PubMed: 30230229
DOI: 10.1111/ajt.15123 -
Transplantation Mar 2024Dynamic preservation methods such as normothermic, subnormothermic, and hypothermic machine perfusion circuits have emerged as viable alternatives to conventional static... (Review)
Review
Dynamic preservation methods such as normothermic, subnormothermic, and hypothermic machine perfusion circuits have emerged as viable alternatives to conventional static cold storage. These organ perfusion technologies serve as preservation methods and enable organ assessment, reconditioning, and repair before transplantation. Gene therapy is a novel strategy with the potential to transform the field of graft optimization and treatment. Thereby specific pathways involved in the transplantation process can be targeted and modified. This review aims to provide an overview of gene delivery methods during ex vivo machine perfusion of kidney and liver grafts. Recent literature on state-of-the-art gene therapy approaches during ex situ organ preservation, especially with respect to ischemia-reperfusion injury, as well as acute and chronic graft rejection have been analyzed. Additionally, potential challenges that could affect further refinement of this therapeutic modality are outlined.
Topics: Perfusion; Kidney; Organ Preservation; Kidney Transplantation; Extracorporeal Circulation
PubMed: 37482634
DOI: 10.1097/TP.0000000000004738 -
The Journal of Thoracic and... Feb 2021Improvement in ex vivo lung perfusion protocols could increase the number of donors available for transplantation and protect the lungs from primary graft dysfunction....
OBJECTIVE
Improvement in ex vivo lung perfusion protocols could increase the number of donors available for transplantation and protect the lungs from primary graft dysfunction. We hypothesize that perfusate adsorption during ex vivo lung perfusion reconditions the allograft to ischemia-reperfusion injury after lung transplantation.
METHODS
Donor pig lungs were preserved for 24 hours at 4°C, followed by 6 hours of ex vivo lung perfusion according to the Toronto protocol. The perfusate was additionally adsorbed through a CytoSorb adsorber (CytoSorbents, Berlin, Germany) in the treatment group, whereas control lungs were perfused according to the standard protocol (n = 5, each). Ex vivo lung perfusion physiology and biochemistry were monitored. Upon completion of ex vivo lung perfusion, a left single lung transplantation was performed. Oxygenation function and lung mechanics were assessed during a 4-hour reperfusion period. The inflammatory response was determined during ex vivo lung perfusion and reperfusion.
RESULTS
The cytokine concentrations in the perfusate were markedly lower with the adsorber, resulting in improved ex vivo lung perfusion physiology and biochemistry during the 6-hour perfusion period. Post-transplant dynamic lung compliance was markedly better during the 4-hour reperfusion period in the treatment group. Isolated allograft oxygenation function and dynamic compliance continued to be superior in the adsorber group at the end of reperfusion, accompanied by a markedly decreased local inflammatory response.
CONCLUSIONS
Implementation of an additional cytokine adsorber has refined the standard ex vivo lung perfusion protocol. Furthermore, cytokine removal during ex vivo lung perfusion improved immediate post-transplant graft function together with a less intense inflammatory response to reperfusion in pigs. Further studies are warranted to understand the beneficial effects of perfusate adsorption during ex vivo lung perfusion in the clinical setting.
Topics: Adsorption; Animals; Cytokines; Female; Humans; Lung; Lung Transplantation; Meropenem; Methylprednisolone; Perfusion; Swine; Treatment Outcome
PubMed: 32201002
DOI: 10.1016/j.jtcvs.2019.12.128 -
Ultrasound in Medicine & Biology Jan 2022Materials with well-characterized acoustic properties are of great interest for the development of tissue-mimicking phantoms with designed (micro)vasculature networks....
Materials with well-characterized acoustic properties are of great interest for the development of tissue-mimicking phantoms with designed (micro)vasculature networks. These represent a useful means for controlled in-vitro experiments to validate perfusion imaging methods such as Doppler and contrast-enhanced ultrasound (CEUS) imaging. In this work, acoustic properties of seven tissue-mimicking phantom materials at different concentrations of their compounds and five phantom case materials are characterized and compared at room temperature. The goal of this research is to determine the most suitable phantom and case material for ultrasound perfusion imaging experiments. The measurements show a wide range in speed of sound varying from 1057 to 1616 m/s, acoustic impedance varying from 1.09 to 1.71 × 10 kg/ms, and attenuation coefficients varying from 0.1 to 22.18 dB/cm at frequencies varying from 1 MHz to 6 MHz for different phantom materials. The nonlinearity parameter B/A varies from 6.1 to 12.3 for most phantom materials. This work also reports the speed of sound, acoustic impedance and attenuation coefficient for case materials. According to our results, polyacrylamide (PAA) and polymethylpentene (TPX) are the optimal materials for phantoms and their cases, respectively. To demonstrate the performance of the optimal materials, we performed power Doppler ultrasound imaging of a perfusable phantom, and CEUS imaging of that phantom and a perfusion system. The obtained results can assist researchers in the selection of the most suited materials for in-vitro studies with ultrasound imaging.
Topics: Acoustics; Perfusion; Perfusion Imaging; Phantoms, Imaging; Ultrasonography
PubMed: 34654580
DOI: 10.1016/j.ultrasmedbio.2021.09.004 -
Anesthesia and Analgesia Apr 2016It is unclear whether maintaining pulmonary perfusion and ventilation during cardiopulmonary bypass (CPB) reduces pulmonary inflammatory tissue injury compared with...
BACKGROUND
It is unclear whether maintaining pulmonary perfusion and ventilation during cardiopulmonary bypass (CPB) reduces pulmonary inflammatory tissue injury compared with standard CPB where the lungs are not ventilated and are minimally perfused. In this study, we tested the hypothesis that maintenance of lung perfusion and ventilation during CPB decreases regional lung inflammation, which may result in less pulmonary structural damage.
METHODS
Twenty-seven pigs were randomly allocated into a control group only submitted to sternotomy (n = 8), a standard CPB group (n = 9), or a lung perfusion group (n = 10), in which lung perfusion and ventilation were maintained during CPB. Hemodynamics, gas exchanges, respiratory mechanics, and systemic interleukins (ILs) were determined at baseline (T0), at the end of 90 minutes of CPB (T90), and 180 minutes after CPB (T180). Bronchoalveolar lavage (BAL) ILs were obtained at T0 and T180. Dorsal and ventral left lung tissue samples were examined for optical and electron microscopy.
RESULTS
At T90, there was a transient reduction in PaO2/FIO2 in CPB (126 ± 64 mm Hg) compared with the control and lung perfusion groups (296 ± 46 and 244 ± 57 mm Hg; P < 0.001), returning to baseline at T180. Serum ILs were not different among the groups throughout the study, whereas there were significant increases in BAL IL-6 (P < 0.001), IL-8 (P < 0.001), and IL-10 (P < 0.001) in both CPB and lung perfusion groups compared with the control group. Polymorphonuclear counts within the lung tissue were smaller in the lung perfusion group than in the CPB group (P = 0.006). Electron microscopy demonstrated extrusion of surfactant vesicles into the alveolar spaces and thickening of the alveolar septa in the CPB group, whereas alveolar and capillary histoarchitecture was better preserved in the lung perfusion group.
CONCLUSIONS
Maintenance of lung perfusion and ventilation during CPB attenuated early histologic signs of pulmonary inflammation and injury compared with standard CPB. Although increased compared with control animals, there were no differences in serum or BAL IL in animals receiving lung ventilation and perfusion during CPB compared with standard CPB.
Topics: Animals; Cardiopulmonary Bypass; Lung; Male; Perfusion; Pneumonia; Respiration, Artificial; Swine
PubMed: 26991612
DOI: 10.1213/ANE.0000000000001118 -
Placenta Jun 2022In pregnancy, aldosterone is linked to maternal plasma volume expansion, improved fetal and placental growth/angiogenesis and reduced maternal blood pressure....
INTRODUCTION
In pregnancy, aldosterone is linked to maternal plasma volume expansion, improved fetal and placental growth/angiogenesis and reduced maternal blood pressure. Aldosterone levels are low in women with pre-eclampsia. Given the placental growth properties of aldosterone in pregnancy, we hypothesised that increased aldosterone improves placental function ex vivo. We applied aldosterone in the dual human placenta perfusion model and analysed specific regulatory markers.
METHODS
A single cotyledon was perfused using a trimodal perfusion setup consisting of a control phase (CP; basic perfusion medium (BPM) alone) and two consecutive experimental phases (EP1/EP2; BPM supplemented with 1.5 x 10M and 1.5 x 10M aldosterone, respectively). CP and EP1/EP2 were conducted in closed circuits lasting 2 h each. Quality/time control perfusions using BPM alone were performed for 360 min to distinguish time-dependent effects from aldosterone-related effects. Perfusates were assessed for control parameters (pH/pO/pCO/glucose/lactate/creatinine/antipyrine). Maternal perfusates were analysed for placental growth factor (PlGF), soluble fms-like tyrosine kinase-1 (sFlt-1), interleukin-10 (IL-10) and tumour necrosis factor-alpha (TNF-α) using ELISAs. mRNA expression of abovementioned factors was measured by qPCR in post-perfusion tissue.
RESULTS
Data from quality/time control perfusions indicated that TNF-α and IL-10 release continuously increased over time. Contrary, in the trimodal perfusion setup the application of aldosterone decreased TNF-α secretion (P < 0.05, EP1/EP2 vs CP, 120 min) and increased PlGF release (P < 0.05, EP1 vs CP, 90/120 min) into the maternal perfusates. mRNA expression followed similar trends, but did not reach significance.
DISCUSSION
Our ex vivo placental perfusion data suggest that increasing aldosterone promotes anti-inflammatory and pro-angiogenic factors, which could positively contribute to healthy pregnancy outcomes.
Topics: Aldosterone; Female; Humans; Interleukin-10; Perfusion; Placenta; Placenta Growth Factor; Pre-Eclampsia; Pregnancy; Pregnancy Outcome; RNA, Messenger; Tumor Necrosis Factor-alpha; Vascular Endothelial Growth Factor Receptor-1
PubMed: 35537250
DOI: 10.1016/j.placenta.2022.03.129 -
Liver Transplantation : Official... Dec 2018Hypothermic oxygenated perfusion (HOPE) and normothermic perfusion are seen as distinct techniques of ex situ machine perfusion of the liver. We aimed to demonstrate the...
Hypothermic oxygenated perfusion (HOPE) and normothermic perfusion are seen as distinct techniques of ex situ machine perfusion of the liver. We aimed to demonstrate the feasibility of combining both techniques and whether it would improve functional parameters of donor livers into transplant standards. Ten discarded human donor livers had either 6 hours of normothermic perfusion (n = 5) or 2 hours of HOPE followed by 4 hours of normothermic perfusion (n = 5). Liver function was assessed according to our viability criteria; markers of tissue injury and hepatic metabolic activity were compared between groups. Donor characteristics were comparable. During the hypothermic perfusion phase, livers down-regulated mitochondrial respiration (oxygen uptake, P = 0.04; partial pressure of carbon dioxide perfusate, P = 0.04) and increased adenosine triphosphate levels 1.8-fold. Following normothermic perfusion, those organs achieved lower tissue expression of markers of oxidative injury (4-hydroxynonenal, P = 0.008; CD14 expression, P = 0.008) and inflammation (CD11b, P = 0.02; vascular cell adhesion molecule 1, P = 0.05) compared with livers that had normothermic perfusion alone. All livers in the combined group achieved viability criteria, whereas 40% (2/5) in the normothermic group failed (P = 0.22). In conclusion, this study suggests that a combined protocol of hypothermic oxygenated and normothermic perfusions might attenuate oxidative stress, tissue inflammation, and improve metabolic recovery of the highest-risk donor livers compared with normothermic perfusion alone.
Topics: Allografts; Biomarkers; Cold Ischemia; Donor Selection; Feasibility Studies; Humans; Liver; Liver Function Tests; Liver Transplantation; Organ Preservation; Oxidative Stress; Perfusion; Warm Ischemia
PubMed: 30058119
DOI: 10.1002/lt.25315 -
Transplant International : Official... 2023Pancreas transplantation is the only curative treatment for patients with complicated diabetes, and organ shortage is a common and increasing problem. Strategies to...
Pancreas transplantation is the only curative treatment for patients with complicated diabetes, and organ shortage is a common and increasing problem. Strategies to expand the donor pool are needed, and normothermic perfusion of the pancreas has the potential to test and repair grafts before implantation. Between January 2021 and April 2022, six human pancreases, declined for transplantation or islet isolation, were perfused using a previously established method by our group. All 6 cases were successfully perfused for 4 h, with minimal edema. The mean age of the donors was 44.16 ± 13.8 years. Five grafts were obtained from neurological death donors, and one was obtained from a donation after cardiac death. The mean glucose and lactate levels decreased throughout perfusion and insulin levels increased. All 6 grafts were metabolically active during perfusion and histopathology showed minimal tissue injury and no edema. Human normothermic perfusion of the pancreas is feasible and safe and has the potential to expand the donor pool. Future studies will focus on tests and biomarkers for the assessment of grafts.
Topics: Humans; Adult; Middle Aged; Organ Preservation; Feasibility Studies; Perfusion; Tissue Donors; Pancreas; Allografts
PubMed: 37252614
DOI: 10.3389/ti.2023.10936