Preservation Injury Research Articles

Cathepsin K-Positive Cell Lineage Promotes In Situ Dentin Formation Controlled by Nociceptive Sonic Hedgehog.

Oral diseases affect nearly half of the global population throughout their lifetime causing pain, as estimated by the World Health Organization. Preservation of vital pulp is the therapeutic core as well as a challenge to protect natural teeth. Current bottleneck lies in that the regenerative capacity of injured pulp is undetermined. In this study, we identified a lifelong lineage that is labelled by cathepsin K (Ctsk) contributing to the physiological, reactionary and reparative odontogenesis of mouse molars. Ctsk+ cell-mediated dentin formation is regulated by nociceptive nerve-derived Sonic Hedgehog (Shh), especially rapidly responsive to acute injury. Notably, exogenous Shh protein to the injury pulp can preserve Ctsk+ cell capacity of odontogenesis for the nearby crown pulp and even remote root apex growth, alleviating conventionally developmental arrest in youth pulpitis. Exposed to chronical attrition, aged pulp Ctsk+ cells still hold the capacity to respond to acute stimuli and promote reparative odontogenesis, also enhanced by exogenous Shh capping. Therefore, Ctsk+ cells may be one of the lineages for accelerating precision medicine for efficient pulp treatment across ages. Shh application can be a candidate for vital pulp preservation and pulp injury repair by promoting regenerative odontogenesis to a certain extent from young adults to older individuals.

Thyroid hormone protects human lung epithelial cells from cold preservation and warm reperfusion-induced injury

BackgroundCellular stress associated with static-cold storage (SCS) and warm reperfusion of donor lungs can contribute to ischemia–reperfusion (IR) injury during transplantation. Adding cytoprotective agents to the preservation solution may be conducive to reducing graft deterioration and improving post-transplant outcomes.MethodsSCS and warm reperfusion were simulated in human lung epithelial cells (BEAS-2B) by exposing cells to low potassium dextran glucose solution at 4 °C for different periods and then switching back to serum-containing culture medium at 37 °C. Transcriptomic analysis was used to explore potential cytoprotective agents. Based on its results, cell viability, caspase activity, cell morphology, mitochondrial function, and inflammatory gene expression were examined under simulated IR conditions with or without thyroid hormones (THs).ResultsAfter 18 h SCS followed by 2 h warm reperfusion, genes related to inflammation and cell death were upregulated, and genes related to protein synthesis and metabolism were downregulated in BEAS-2B cells, which closely mirrored gene profiles found in thyroid glands of mice with congenital hypothyroidism. The addition of THs (T3 or T4) to the preservation solution increases cell viability, inhibits activation of caspase 3, 8 and 9, preserves cell morphology, enhances mitochondrial membrane potential, reduces mitochondrial superoxide production, and suppresses inflammatory gene expression.ConclusionAdding THs to lung preservation solutions may protect lung cells during SCS by promoting mitochondrial function, reducing apoptosis, and inhibiting pro-inflammatory pathways. Further in vivo testing is warranted to determine the potential clinical application of adding THs as therapeutics in lung preservation solutions.

Innate immune modulation in transplantation: mechanisms, challenges, and opportunities.

Organ transplantation is characterized by a sequence of steps that involve operative trauma, organ preservation, and ischemia-reperfusion injury in the transplant recipient. During this process, the release of damage-associated molecular patterns (DAMPs) promotes the activation of innate immune cells via engagement of the toll-like receptor (TLR) system, the complement system, and coagulation cascade. Different classes of effector responses are then carried out by specialized populations of macrophages, dendritic cells, and T and B lymphocytes; these play a central role in the orchestration and regulation of the inflammatory response and modulation of the ensuing adaptive immune response to transplant allografts. Organ function and rejection of human allografts have traditionally been studied through the lens of adaptive immunity; however, an increasing body of work has provided a more comprehensive picture of the pivotal role of innate regulation of adaptive immune responses in transplant and the potential therapeutic implications. Herein we review literature that examines the repercussions of inflammatory injury to transplantable organs. We highlight novel concepts in the pathophysiology and mechanisms involved in innate control of adaptive immunity and rejection. Furthermore, we discuss existing evidence on novel therapies aimed at innate immunomodulation and how this could be harnessed in the transplant setting.

Cardioprotective effect of Interleukin-11 against warm ischemia-reperfusion injury in a rat heart donor model

Shortage of donor organs for heart transplantation is a worldwide problem. Donation after circulatory death (DCD) has been proposed to expand the donor pool. However, in contrast to the donation after brain death that undergoes immediate cold preservation, warm ischemia and subsequent reperfusion injury are inevitable in DCD. It has been reported that interleukin-11 (IL-11) mitigates ischemia-reperfusion injury in rodent models of myocardial infarction and donation after brain death heart transplantation. We hypothesized that IL-11 also offers benefit to warm ischemia in an experimental model of cardiac transplantation that resembles DCD. The hearts of naïve male Sprague Dawley rats (n = 15/group) were procured, subjected to 25-min warm ischemia, and reperfused for 60 min using Langendorff apparatus. IL-11 or saline was administered intravenously before the procurement, added to maintenance buffer, and infused via perfusion during reperfusion. IL-11 group exhibited significantly better cardiac function post-reperfusion. Severely damaged mitochondria was found in the electron microscopic analysis of control hearts whereas the mitochondrial structure was better preserved in the IL-11 treated hearts. Immunoblot analysis using neonatal rat cardiomyocytes revealed increased signal transducer and activator of transcription 3 (STAT3) phosphorylation at Ser727 after IL-11 treatment, suggesting its role in mitochondrial protection. Consistent with expected activation of mitochondrial respiration by mitochondrial STAT3, immunohistochemical staining demonstrated a higher mitochondrial cytochrome c oxidase subunit 2 expression. In summary, IL-11 protects the heart from warm ischemia reperfusion injury by alleviating mitochondrial injury and could be a viable therapeutic option for DCD heart transplantation.

Mechanisms of Cold Preservation and Reperfusion Injury for Solid Organ Transplantation: Implications for Partial Heart Transplantations

Cold preservation is a key component to organ procurement and transplantation. Cold preservation functions by slowing metabolic activity of procured organs and begins the period known as cold ischemic time (CIT). Reducing CIT and warm ischemic time (WIT) are paramount to minimizing donor organ damage from ischemia and the build-up of waste products and signals that drive reperfusion injury prior to transplantation into a matching recipient. Preventing damage from CIT and WIT and extending the amount of time that organs can tolerate has been a major goal of organ transplantation since donors and recipients are frequently not located within the same hospital, region, or state. Meanwhile, the amount of CIT that a transplant center is willing to accept differs based on the organ, the institution receiving the organ offer, and the doctor receiving the offer for that institution. With the introduction of a partial heart transplantation conducted last year at Duke University, it is important to discuss how much CIT transplant centers conducting a partial heart transplantation (pHT) are willing to accept. This article will review the physiology of WIT and CIT, associated organ damage, CIT variation among transplant centers and organ types, and provide a brief discussion of the future of pHT-accepted CIT and the need for research in this field.

Evaluation and management of abnormal liver enzymes in the liver transplant recipient: When, why, and what now?

Evaluation and management of abnormal liver enzymes in the liver transplant recipient: When, why, and what now?

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.

Heparin Conjugate Pretreatment of Kidneys From Deceased Donors Before Transplantation: Results From the First-in-human Randomized Phase I Trial.

CHC or placebo was added to the preservation solution during HMP of donated kidneys from deceased donors for at least 3 h before transplantation into adult patients. The primary safety endpoint was the number and severity of adverse events (AEs) and serious AEs (SAEs) during the first 30 d after transplantation. In the first 30 d, 66 AEs were reported in 8 patients who received CHC-pretreated kidneys with 39 AEs in 8 patients who received placebo-pretreated kidneys (P = 0.1 in post hoc analysis). The most common AEs were hypertension (CHC, n = 5; placebo, n = 2) and anemia (CHC, n = 5; placebo, n = 2). Most AEs were assessed as mild (58%) or moderate (39%) and not related to treatment (95%). There were 2 SAEs reported in each group. One SAE, considered possibly related to CHC treatment, was a case of severe postprocedural hemorrhage that required reoperation. No patients needed dialysis. There were no observed rejections and no patient deaths. Pretreatment of kidneys with CHC before transplantation was considered safe and tolerable. Efficacy studies are now planned to investigate if CHC can reduce early ischemia-reperfusion injury in humans.

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.

Luminal Preservation Protects the Small Intestine in a Brain-dead Rat Model.

Background.Intestinal transplantation depends on donation after brain death (DBD). Luminal preservation (LP) has been beneficial against preservation injury in previous studies in animal models, but none include DBD. This study aims to investigate whether these benefits occur also with DBD.Methods.Wistar rats (male, N = 9) underwent brain death for 2 h. Thereafter, vascular perfusion was done with University of Wisconsin solution (UW). The small intestine was then explanted and randomized into 3 groups: control (empty segment), LP+PEG (with polyethylene glycol 3350 solution), or LP+UW (with UW), treated and tied shut. Ice-cold UW was used for cold storage. Samples were taken at procurement and after 4 (t = 4) and 8 h (t = 8) of preservation. Histopathological scorings were performed for intestinal preservation injury, subepithelial space, absence of epithelial lining, and hemeoxygenase-1 expression.Results.There was low-level mucosal injury (median intestinal preservation injury score 2) at procurement. At t = 4, bowels treated without LP had more damage than LP-treated samples (control score 4, LP+PEG 2 and LP+UW 2, P < 0.001 control versus LP+UW). At t = 8, no benefit of LP was observed (control 2, LP+PEG 3, LP+UW 2). Subepithelial space increased with time and the presence of LP; epithelial lining was better conserved in LP-treated samples. Hemeoxygenase-1 staining showed increased intensity with increased damage, irrespective of treatment.Conclusions.Luminal perfusion of the small intestine with UW or PEG protects the mucosa in brain-dead rats for up to 4 h. Fewer benefits of LP were found than previously described in non-DBD models. To mimic the clinical situation, DBD should be included in future animal studies on intestinal preservation.

415.3: AP39 Administration During Normothermic Ex Vivo Kidney Perfusion Reduces Preservation Injury

415.3: AP39 Administration During Normothermic Ex Vivo Kidney Perfusion Reduces Preservation Injury

P11.27: Changes in Markers of Coagulation and Fibrinolysis Offer Insights Into Pathophysiological Aspects of Preservation Injury During Normothermic Liver Perfusion

Background: The perfusate used in normothermic machine perfusion (NMP) is mainly composed of red packed blood cells and colloid solution and is therefore free from thrombocytes and coagulation factors. Our aim was to monitor changes in composition of coagulation factors during NMP and to investigate their association with liver function during NMP and after transplantation. Methods: NMP has been performed on a heterogenous study group of 16 grafts that included 12 extended criteria donor livers. Factor V activity (FV), factor XIII activity (FXIII), van Willebrand factor activity (vWF), D-dimer, plasminogen-activator-inhibitor (PAI-1) and thrombocyte count in perfusate were assessed. Liver and bile duct biopsies were taken before and after perfusion and after reperfusion. Median follow-up after transplantation was 11 months (IQR: 6.4-12). Results: NMP and assessment of 16 livers resulted in 10 livers that were successfully transplanted. Main reasons for decline included inability to clear lactate, low bile quality, or signs of fibrosis in the frozen section. Two livers presented with increased D-dimer levels during perfusion (8.7 µg/mL and 12.3 µg/mL vs. mean peak D-dimer of 3.7 µg/mL SD: 3.1). One liver was transplanted, the histological analysis of the bile duct biopsies taken before implantation showed sclerosing cholangitis. Additionally, vWF activity during perfusion of this liver was increased (13 % vs. mean peak vWF activity of 6.4% SD: 2.5). The recipient had to be treated with a stent for an anastomotic stricture. The second liver with elevated D-dimer was severely steatotic and the only liver out of the study group that did not produce bile and was therefore declined for transplantation. The graft additionally presented with high levels of PAI-1 (299 IU/mL vs. mean peak PAI-1 of 186 IU/mL SD: 155) and increased FXIII activity in perfusate (158 % vs. mean peak FXIII activity 45% SD: 49). PAI-1 was also elevated in another three livers during perfusion, of which one was discarded due to increasing lactate after initial clearing and high grade of steatosis (peak PAI-1 605 IU/mL). Both other livers were successfully transplanted, one of the two recipients later developed an anastomotic stricture. Each of the three cases with increased PAI-1 levels coincided with peaks in either thrombocyte count, bilirubin or FV activity. Conclusion: Changes in perfusate composition of coagulation and fibrinolysis factors offer interesting new insights in pathophysiological aspects of preservation injury and might allow for additional graft assessment during longer courses of NMP. Prospective studies are needed to validate these initial findings.

Effects of polyethylene glycol-20k IV solution on donor management in a canine model of donor brain death.

Traditionally, vasopressors and crystalloids have been used to stabilize brain dead donors; however, the use of crystalloid is fraught with complications. This study aimed to investigate the effectiveness of a newly developed impermeant solution, polyethylene glycol-20k IV solution (PEG-20k) for resuscitation and support of brain dead organ donors. Brain death was induced in adult beagle dogs and a set volume of PEG-20k or crystalloid solution was given thereafter. The animals were then resuscitated over 16h with vasopressors and crystalloid as necessary to maintain mean arterial pressure of 80-100mmHg. The kidneys were procured and cold-stored for 24h, after which they were analyzed using the isolated perfused kidney model. The study group required significantly less crystalloid volume and vasopressors while having less urine output and requiring less potassium supplementation than the control group. Though the two groups' mean arterial pressure and lactate levels were comparable, the study group's kidneys showed less preservation injury after short-term reperfusion indexed by decreased lactate dehydrogenase release and higher creatinine clearance than the control group. The use of polyethylene glycol-20k IV solution for resuscitating brain dead donors decreases cell swelling and improves intravascular volume, thereby improving end organ oxygen delivery before procurement and so preventing ischemia-reperfusion injury after transplantation.

Wanted: An endothelial cell targeting atlas for nanotherapeutic delivery in allograft organs

Despite the profound shortage of organs available for transplant in the U.S., over 5,000 donated organs were declined for use in 2020. Many of these organs were declined due to donor comorbidities or preservation injuries that predispose grafts to rejection and loss. The risks of these poor outcomes can potentially be reduced by pre-transplant application of normothermic machine perfusion (NMP). To date, the clinical use of NMP has focused on extending preservation and improving organ assessment, but the opportunity for ex situ therapeutic delivery may be the most transformative aspect of this technology. In this Personal Viewpoint, we argue that the endothelial cells (ECs) that line the graft vasculature are an accessible, under-exploited, and attractive target for transplant therapeutics delivered during NMP. We further contend that molecularly targeted nanoparticles (NPs) represent a promising therapeutic vehicle particularly well-suited to NMP. However, to achieve this potential, we need to answer the following three key questions: (1) What EC sub-populations exist within an organ? (2) How can these cells be accessed? (3) And most important, how can preferential retention of NPs by the cells of interest be maximized? Here we argue for creating an EC-targeting atlas as a body of knowledge that answers these questions.

Endogenous Cannabinoid Receptors Modulate Plasticity at Immature Synapses

To explore the mechanism of endocannabinoid cannabinoid receptor 1 (CB1) receptor pathway that regulates synaptic plasticity in the dorsal horn of the spinal cord of rats with neuropathic pain at different ages. Neonatal, juvenile, and adult male sprague dawley (SD) rats were divided into the spinal nerve preservation injury (SNI), SNI + Anandamide (AEA), SNI + D-AP5, SNI + CNQX, SNI + D-AP5 + AEA, SNI + CNQX + AEA, sham SNI, sham SNI + AEA, sham SNI + D-AP5, sham SNI + CNQX, sham SNI + D-AP5 + AEA, and sham SNI + CNQX + AEA groups, respectively. Paw withdrawal threshold (PWT) and long-term potentiation (LTP) of the spinal dorsal horn PS (field potential) were assessed to judge the spinal cord's functional state. Immunohistochemical staining and Western blot were conducted to detect CB1 protein levels in the spinal dorsal horn. The LTP response in the spinal cord was alleviated in the SNI + AEA group. After treatment with the N-methyl-D-aspartate (NMDA) receptor blocker D-AP5, the LTP of neonatal A nerve was relieved further. After treatment with the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor blocker CNQX, LTP change in the A nerve was not obvious. The LTP of the A and C nerves were relieved after D-AP5 or CNQX treatment in young and adult animals; however, the blocking effect of CNQX was obvious. The altered levels of PWT and CB1 support these results. The CB1 receptor activation produces analgesia in neonatal rats through NMDA receptor formation for PS inhibitory activity. In juvenile and adult rats, this phenomenon was effectuated through NMDA and AMPA receptors. This difference could be attributed to the varied number of NMDA and/or AMPA receptors activated during development and changes in the NMDA/AMPA receptor ratio.

Study of Rta Patients with SERUM Electrolytes and SERUM Bilirubin Levels

INTRODUCTION:Hyponatremia and hypernatremia are both possible outcomes.Changes in potassium, particularly Hypokalemia, as well as fluid content, are common in clinical practise. The most prevalent reasons are syndrome of inadequate anti-diuretic hormone secretion (SIADH), cerebral salt wasting (CSW), and the use of diuretics such as Furosemide and Mannitol.Another key factor that influences morbidity and mortality is age. Getting older has a negative impact. In most parts of the world, isotonic fluid may be provided without major fluid disruptions in the body, making effective fluid management of patients with traumatic brain injury (TBI) a difficulty.AIM:Study of RTA Patients with Serum Electrolytes and Serum Bilirubin LevelsMATERIAL AND METHOD:This study included total 40 patients comes in IPD and OPD department of medicine &amp; psychiatrics with collaboration in Department of biochemistry Dr. Ulhas Patil Medical College and Hospital Jalgaon, Maharashtra RESULT:In table 1 show that comparison between RTA and traumatic subjects’ serum sodium level are elevated in RTA subjects compare to traumatic subjects. The P value are shows that statistically non-significant P &gt;0.3546.Serum potassium levels are elevated in RTA subjects compare to traumatic subjects. The P value shows that non-significant P &gt;0.8262.CONCLUSION:Our study shows that comparison of RTA and traumatic injury Electrolyte imbalances are particularly common in people who have suffered a brain injury. It is a significant and treatable cause of neurological decline. Serum potassium, calcium, and phosphorus levels should also be checked since they play a role in preventing secondary brain injuries, RTA preservation, and traumatic injury.

Defining the Normal Values for Left Ventricular Global Longitudinal Strain in Adult Heart Transplanted Patients

<h3>Purpose</h3> To date, there are no data about normal values of Global Longitudinal Strain (GLS) in adults post heart transplant. The GLS correlation with heart graft rejection was derived based on the GLS values from normal, native heart population data. The aim of the study is to establish the normal GLS values in heart transplant patients, in order to better define risk of rejection or cardiac allograft vasculopathy (CAV). <h3>Methods</h3> This is a single center, retrospective study of consecutive patients from January 1, 2018 to September 1, 2021 who underwent orthotopic heart transplantation. Patients were excluded if post-transplant transthoracic echocardiography with myocardial strain imaging was not performed or if they were treated for rejection. Left ventricular ejection fraction (EF) and strain, were collected for patients at 1-month, 3-months, 6-months, 12-months, and 18-months post-transplant. Results at each time point were described with univariate analysis. Analysis of variance (ANOVA) was then utilized to compare the echocardiographic findings. <h3>Results</h3> Thirty-five patients were included in this study and all of them had echocardiography with GLS performed at the time intervals specified. The mean EF was stable over time from 60.0% ± 6.3% at 1-month post-transplant to 61.9% ± 5.9% at 18-months (Fig 1a). No significant difference in EF between timepoints was detected (p=0.5). The mean GLS increased over time from -14.9 ± 3.4 at 1-month post-transplant to -16.9 ± 3.4 at 18-months (p=0.6). (Fig 1b), but lower than in normal hearts. <h3>Conclusion</h3> This study established normal values of GLS in patients undergoing serial echocardiography after orthotopic heart transplantation that is different from values seen in normal hearts. The lower GLS values at 1 month post-transplant despite normal LVEF, as marker of subclinical LV dysfunction, are probably due to preservation injury and/or reperfusion ischemia. Based on our data, new GLS values should drive consideration of rejection.

The effect of end-ischaemic normothermic machine perfusion on donor hepatic artery endothelial integrity.

Ex vivo normothermic machine liver perfusion (NMLP) involves artificial cannulation of vessels and generation of flow pressures. This could lead to shear stress-induced endothelial damage, predisposing to vascular complications, or improved preservation of donor artery quality. This study aims to assess the spatial donor hepatic artery (HA) endothelial quality downstream of the cannulation site after end-ischaemic NMLP. Remnant HA segments from the coeliac trunk up to the gastroduodenal artery branching were obtained after NMLP (n = 15) and after static cold storage (SCS) preservation (n = 15). Specimens were fixed in 10% neutral buffered formalin and sectioned at pre-determined anatomical sites downstream of the coeliac trunk. CD31 immunohistostaining was used to assess endothelial integrity by a 5-point ordinal scale (grade 0: intact endothelial lining, grade 5: complete denudation). Endothelial integrity after SCS was used as a control for the state of the endothelium at commencement of NMP. In the SCS specimens, regardless of the anatomical site, near complete endothelial denudation was present throughout the HA (median scores 4.5-5). After NMLP, significantly less endothelial loss in the distal HA was present compared to SCS grafts (NMLP vs. SCS: median grade 3 vs. 4.5; p = 0.042). In NMLP specimens, near complete endothelial denudation was present at the cannulation site in all cases (median grade: 5), with significantly less loss of the endothelial lining the further from the cannulation site (proximal vs. distal, median grade 5 vs. 3; p = 0.005). Loss of endothelial lining throughout the HA after SCS and at the cannulation site after NMLP suggests extensive damage related to surgical handling and preservation injury. Gradual improved endothelial lining along more distal sites of the HA after NMLP indicates potential for re-endothelialisation. The regenerative effect of NMLP on artery quality seems to occur to a greater extent further from the cannulation site. Therefore, arterial cannulation for machine perfusion of liver grafts should ideally be as proximal as possible on the coeliac trunk or aortic patch, while the site of anastomosis should preferentially be attempted distal on the common HA.

Prolonged Normothermic Ex Vivo Kidney Perfusion Is Superior to Cold Nonoxygenated and Oxygenated Machine Perfusion for the Preservation of DCD Porcine Kidney Grafts.

Background.The increased usage of marginal grafts has triggered interest in perfused kidney preservation to minimize graft injury. We used a donation after circulatory death (DCD) porcine kidney autotransplantation model to compare 3 of the most frequently used ex vivo kidney perfusion techniques: nonoxygenated hypothermic machine perfusion (non-oxHMP), oxygenated hypothermic machine perfusion (oxHMP), and normothermic ex vivo kidney perfusion (NEVKP).Methods.Following 30 min of warm ischemia, grafts were retrieved and preserved with either 16 h of non-oxHMP, oxHMP, or NEVKP (n = 5 per group). After contralateral nephrectomy, grafts were autotransplanted and animals were followed for 8 d. Kidney function and injury markers were compared between groups.Results.NEVKP demonstrated a significant reduction in preservation injury compared with either cold preservation method. Grafts preserved by NEVKP showed superior function with lower peak serum creatinine (NEVKP versus non-oxHMP versus oxHMP: 3.66 ± 1.33 mg/dL, 8.82 ± 3.17 mg/dL, and 9.02 ± 5.5 mg/dL) and more rapid recovery. The NEVKP group demonstrated significantly increased creatinine clearance on postoperative day 3 compared with the cold perfused groups. Tubular injury scores on postoperative day 8 were similar in all groups.Conclusions.Addition of oxygen during HMP did not reduce preservation injury of DCD kidney grafts. Grafts preserved with prolonged NEVKP demonstrated superior initial graft function compared with grafts preserved with non-oxHMP or oxHMP in a model of pig DCD kidney transplantation.

P-07: Segmental Susceptibility of Intestinal Stem Cells to Cold Storage Preservation Injury in a Porcine Model

P-07: Segmental Susceptibility of Intestinal Stem Cells to Cold Storage Preservation Injury in a Porcine Model