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Current graft evaluation during normothermic ex situ liver perfusion lacks real-time parameters for predicting posttransplant hepatocyte and biliary function. Indocyanine green (ICG) imaging has been widely used in liver surgery, enabling the visualization of hepatic uptake and excretion through bile using near-infrared light. In this research, porcine livers under various ischemic conditions were examined during a 5-hour normothermic ex situ liver perfusion procedure, introducing ICG at 1 hour through the hepatic artery. These conditions included livers from heart-beating donors, donation after circulatory death (DCD) with warm ischemic durations of 60 minutes (DCD60) and 120 minutes (DCD120), as well as interventions utilizing tissue plasminogen activator in DCD120 cases (each n = 5). Distinct hepatic fluorescence patterns correlated with different degrees of ischemic injury ( p = 0.01). Low ICG uptake in the parenchyma (less than 40% of maximum intensity) was more prevalent in DCD120 (21.4%) compared to heart-beating donors (6.2%, p = 0.06) and DCD60 (3.0%, p = 0.02). Moreover, ICG clearance from 60 minutes to 240 minutes was significantly higher in heart-beating donors (69.3%) than in DCD60 (17.5%, p < 0.001) and DCD120 (32.1%, p = 0.01). Furthermore, thrombolytic intervention using tissue plasminogen activator in DCD120 resulted in noteworthy outcomes, including significantly reduced ALP levels ( p = 0.04) and improved ICG clearance ( p = 0.02) with a trend toward mitigating fibrin deposition similar to DCD60, as well as enhancements in bile production ( p = 0.09). In conclusion, ICG fluorescence imaging during normothermic ex situ liver perfusion provides real-time classification of hepatic vascular and biliary injuries, offering valuable insights for the more accurate selection and postintervention evaluation of marginal livers in transplantation., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc.)

A 45 year old male obese patient with a previous history of repaired congenital heart disease developed worsening heart failure making heart transplantation listing mandatory. Unfortunately, due to his anthropometric measures, the search for a suitable brain-dead donor was unsuccessful. For this reason, he accepted to be enrolled in the controlled donation after circulatory death (cDCD) program. According to the Italian Law regulating death declaration after cardiac arrest (no-touch period of 20 minutes-one of the longest in the world), we faced a 34 minute cardiac asystole, after which the heart was recovered through a thoraco-abdominal normothermic regional perfusion excluding the epiaortic vessels. The heart was then preserved by means of cold static storage. Heart transplantation was performed successfully without any signs of primary graft failure. Postoperative endomyocardial biopsies were negative for acute cellular and antibody-mediated rejection. Furthermore, echocardiographic and cardiac magnetic resonance evaluation of the heart did not show any functional abnormalities. The patient was discharged on post-operative day (POD) #39 in good clinical conditions., Competing Interests: Disclosure: The authors have no conflicts of interest to report., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the ASAIO.)

Prolonged warm ischemic is the main cause discarding donated organs after cardiac death. Here, we identified that prolonged warm ischemic time induced disseminated intravascular coagulation and severe capillary vasospasm after cardiac death of rat kidneys. Additionally, we found a significant accumulation of fibrinogen in a hypoxic cell culture of human umbilical vein epithelial cells and in isolated kidneys exposed to prolonged warm ischemic following flushing out of blood. However, pre-flushing the kidney with snake venom plasmin in a 90-minute warm ischemic model maximized removal of micro thrombi and facilitated the delivery of oxygen and therapeutic agents. Application of carbon monoxide-releasing CORM-401 during ex vivo hypothermic oxygenated perfusion achieved multipath protective effects in prolonged warm ischemic kidneys. This led to significant improvements in perfusion parameters, restoration of the microcirculation, amelioration of mitochondrial injury, oxidative stress, and apoptosis. This benefit resulted in significantly prolonged warm ischemic kidney recipient survival rates of 70%, compared with none in those receiving ex vivo hypothermic oxygenated perfusion alone. Significantly, ex vivo hypothermic oxygenated perfusion combined with cytoprotective carbon monoxide releasing CORM-401 treatment meaningfully protected the donated kidney after cardiac death from ischemia-reperfusion injury by reducing inflammation, oxidative stress, apoptosis, and pathological damage. Thus, our study suggests a new combination treatment strategy to potentially expand the donor pool by increasing use of organs after cardiac death and salvaging prolonged warm ischemic kidneys., (Copyright © 2024 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.)

Background: Withdrawal of life-sustaining therapy (WLST) performed in the circulatory determination of death (DCD) donors leads to cardiac arrest, challenging the utilization of the myocardium for transplantation. The rapid initiation of normothermic regional perfusion or extracorporeal membrane oxygenation after death helps to optimize organs before implantation. However, additional strategies to mitigate the effects of stress response during WLST, hypoxic/ischemic injury, and reperfusion injury are required to allow myocardium recovery., Methods: To this aim, our team routinely used a preconditioning protocol for each DCD donation before and during the WLST and after normothermic regional perfusion/extracorporeal membrane oxygenation. The protocol includes pharmacological treatments combined to reduce oxidative stress (melatonin, N -acetylcysteine, and ascorbic acid), improve microcirculation (statins), and mitigate organ's ischemic injury (steroids) and organ ischemia/reperfusion injury (remifentanil and sevoflurane when the heart is available for transplantation)., Results: This report presents the first case of recovery of cardiac function, with the only support of normothermic regional reperfusion, following 20 min of a no-touch period and 41 min of functional warm ischemic time in a DCD donor after the preconditioning protocol., Conclusions: Our protocol seems to be effective in abolishing the stress response during WLST and, on the other hand, particularly organ protective (and heart protective), giving a chance to donate organs less impaired from ischemia/reperfusion injury., Competing Interests: The authors declare no funding or conflicts of interest., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Objectives: Lung transplant warm ischemia-reperfusion injury (IRI) results in cellular injury, inflammation, and poor graft function. Mitsugumin 53 (MG53) is an endogenous protein with cell membrane repair properties and the ability to modulate the inflammasome. We hypothesize that the absence of circulating MG53 protein in the recipient increases IRI, and higher levels of circulating MG53 protein mitigate IRI associated with lung transplantation., Methods: To demonstrate protection, wild-type (wt) lung donor allografts were transplanted into a wt background, a MG53 knockout (mg53-/-), or a constitutively overexpressed MG53 (tissue plasminogen activator-MG53) recipient mouse after 1 hour of warm ischemic injury. Mice survived for 5 days after transplantation. Bronchioalveolar lavage, serum, and tissue were collected at sacrifice. Bronchioalveolar lavage, serum, and tissue markers of apoptosis and a biometric profile of lung health were analyzed., Results: mg53-/- mice had significantly greater levels of markers of overall cell lysis and endothelial cell injury. Overexpression of MG53 resulted in a signature similar to that of wt controls. At the time of explant, tissue plasminogen activator-MG53 recipient tissue expressed significantly greater levels of MG53, measured by immunohistochemistry, compared with mg53-/-, demonstrating uptake of endogenous overexpressed MG53 into donor tissue., Conclusions: In a warm IRI model of lung transplantation, the absence of MG53 resulted in increased cell injury and inflammation. Endogenous overexpression of MG53 in the recipient results in protection in the wt donor. Together, these data suggest that MG53 is a potential therapeutic agent for use in lung transplantation to mitigate IRI., Competing Interests: Conflict of Interest Statement J.M. is a founder of TRIM-edicine, Inc, a university spin-off biotechnology company that develops MG53 for regenerative medicine application. B.A.W. serves on the Clinical Events Committee of TransMedics OCS. All other authors reported no conflicts of interest. The Journal policy requires editors and reviewers to disclose conflicts of interest and to decline handling or reviewing manuscripts for which they may have a conflict of interest. The editors and reviewers of this article have no conflicts of interest., (Copyright © 2023. Published by Elsevier Inc.)

Background: In Italy, 20 min of continuous, flat-line electrocardiogram are required for death declaration. Despite prolonged warm ischemia time, Italian centers reported good outcomes in controlled donation after circulatory death (cDCD) liver transplantation by combining normothermic regional and end-ischemic machine perfusion (MP). The aim of this study was to evaluate the safety and feasibility of the use of septuagenarian and octogenarian cDCD donors with this approach., Methods: All cDCD older than 70 y were evaluated during normothermic regional perfusion and then randomly assigned to dual hypothermic or normothermic MP., Results: In the period from April 2021 to December 2022, 17 cDCD older than 70 y were considered. In 6 cases (35%), the graft was not considered suitable for liver transplantation, whereas 11 (65%) were evaluated and eventually transplanted. The median donor age was 82 y, being 8 (73%) older than 80. Median functional warm ischemia and no-flow time were 36 and 28 min, respectively. Grafts were randomly assigned to ex situ dual hypothermic oxygenated MP in 6 cases (55%) and normothermic MP in 5 (45%). None was discarded during MP. There were no cases of primary nonfunction, 1 case of postreperfusion syndrome (9%) and 2 cases (18%) of early allograft dysfunction. At a median follow-up of 8 mo, no vascular complications or ischemic cholangiopathy were reported. No major differences were found in terms of postoperative hospitalization or complications based on the type of MP., Conclusions: The implementation of sequential normothermic regional and end-ischemic MP allows the safe use of very old donation after circulatory death donors., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Normothermic machine perfusion (NMP) is a promising pretransplant kidney quality assessment platform, but it remains crucial to increase its diagnostic potential while ensuring minimal additional injury to the already damaged kidney. Interventions that alter tubular transport can influence renal function and injury during perfusion. This study aimed to determine whether furosemide and desmopressin affect renal function and injury during NMP., Methods: Eighteen porcine kidneys (n = 6 per group) were subjected to 30 min of warm ischemia and 4 h of oxygenated hypothermic perfusion before being subjected to 6 h of NMP. Each organ was randomized to receive no drug, furosemide (750 mg), or desmopressin (16 μg) during NMP., Results: Compared with the other groups, the addition of furosemide resulted in significantly increased urine output, fractional excretion of sodium and potassium, and urea clearance during NMP. Urinary neutrophil gelatinase-associated lipocalin levels decreased significantly with furosemide supplementation compared with the other groups. The addition of desmopressin did not result in any significantly different outcome measurements compared with the control group., Conclusions: This study showed that the addition of furosemide affected renal function while attenuating tubulointerstitial injury during NMP. Therefore, furosemide supplementation may provide renal protection and serve as a functional test for pretransplant kidney viability assessment during NMP., (© 2023 The Authors. Artificial Organs published by International Center for Artificial Organ and Transplantation (ICAOT) and Wiley Periodicals LLC.)

Background: Individual events during donation after circulatory death (DCD) procurement, such as hypotensive or hypoxic warm ischemia, or circulatory arrest are all a part of donor warm ischemia time (dWIT), and may have differing effects on the outcome of the liver graft. This study aimed to identify risk factors for postreperfusion syndrome (PRS), a state of severe hemodynamic derangement following graft reperfusion, and its impact on DCD liver transplantation (LT) outcomes., Methods: This was a retrospective analysis using 106 DCD LT. Detailed information for events during procurement (withdrawal of life support; systolic blood pressure < 80 mmHg; oxygen saturation < 80%; circulatory arrest; aortic cold perfusion) and their association with the development of PRS were examined using logistic regression., Results: The overall incidence of PRS was 26.4%, occurring in 28 patients. Independent risk factors for PRS were asystolic dWIT (odds ratio (OR) 3.65, 95% confidence interval (CI) 1.38-9.66) and MELD score (OR 1.06, 95% CI 1.01-1.10). Total bilirubin was significantly higher in the PRS group at postoperative day (POD) 1 (p = .02; 5.2 mg/dL vs. 3.4 mg/dL), POD 3 (p = .049; 4.5 mg/dL vs. 2.8 mg/dL), and POD 7 (p = .04; 3.1 mg/dL vs. 1.9 mg/dL). Renal replacement therapy after LT was more likely to be required in the PRS group (p = .01; 48.2% vs. 23.1%)., Conclusion: Asystolic dWIT is a risk factor for the development of PRS in DCD LT. Our results suggest that asystolic dWIT should be considered when selecting DCD liver donors., (© 2024 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Liver failure secondary to metabolic dysfunction-associated steatotic liver disease (MASLD) has become the most common cause for liver transplantation in many parts of the world. Moreover, the prevalence of MASLD not only increases the demand for liver transplantation, but also limits the supply of suitable donor organs because steatosis predisposes grafts to ischemia-reperfusion injury (IRI). There are currently no pharmacological interventions to limit hepatic IRI because the mechanisms by which steatosis leads to increased injury are unclear. To identify potential novel mediators of IRI, we used liquid chromatography and mass spectrometry to assess temporal changes in the hepatic lipidome in steatotic and non-steatotic livers after warm IRI in mice. Our untargeted analyses revealed distinct differences between the steatotic and non-steatotic response to IRI and highlighted dynamic changes in lipid composition with marked changes in glycerophospholipids. These findings enhance our knowledge of the lipidomic changes that occur following IRI and provide a foundation for future mechanistic studies. A better understanding of the mechanisms underlying such changes will lead to novel therapeutic strategies to combat IRI., (© 2024. The Author(s).)

Background: The limitation of ischemia times, which damages the organs and impacts transplant outcomes, is a drawback of controlled donation after circulatory death., Methods: The aim of the study was to analyze the influence of preservation and ischemia times on overall survival and both censured graft survival and overall graft survival. This was an observational and retrospective study of patients undergoing liver transplantation with grafts from controlled donation after circulatory death between November 2013 and November 2022., Results: Sixty-five patients were included in the study. Twenty percent (12 patients) developed early graft dysfunction according to Olthoff's classification, and 7 patients (11.6%) scored ≥7 points according to the Model for Early Allograft Function Scoring scale. Five patients (7.6%) met the criteria for primary graft failure. The retransplantation rate was 9.2% (6 cases). Fifty patients (76.9%) remained alive, and 15 patients (23.1%) died. When analyzing overall survival based on the main preservation and ischemia times, we observed that the best results occurred in the group with a functional warm ischemia time <12 minutes, with a survival rate at 1, 3, and 5 years of 95.8%, 87.1%, and 87.1%, respectively (P = .043). Regarding the analysis of censured graft survival based on the main preservation and ischemia times, we found that the worst results occurred in the group with a cold ischemia time ≥6 hours, with a survival rate of around 48% at 3 and 5 years (P = .047)., Conclusions: High-risk patients have lower overall and graft survival in the short and long term in grafts from controlled donation after circulatory death., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Objectives: To analyze the factors relative to the short-term preservation of ipsilateral renal function after partial nephrectomy. Methods: The clinical data of 83 patients who were treated with partial nephrectomy from December 2014 to December 2019 in the Department of Urology, Sun Yat-sen University Cancer Center were retrospectively analyzed. There were 54 males and 29 females, aging ( M (IQR)) 49 (17) years (range: 27 to 74 years). The ischemia time in operation was 25 (18) minutes (range: 10 to 67 minutes). Emission computed tomography scan and CT scan were performed before (within 1 month) and after (3 to 12 months) surgery. The volume of the ipsilateral and contralateral kidney was measured on the basis of preoperative and postoperative CT scans. The glomerular filtration rate (GFR) specifically in each kidney was estimated by emission computed tomography. Recovery from ischemia is determined by the formula: GFR preservation/volume saved×100%. Linear regression was used to explore the factors ralative to the short-term preservation of ipsilateral renal function after partial nephrectomy. Results: The GFR preservation of the ipsilateral kidney was 80.9 (25.2) % (range: 31.0% to 109.4%). The volume loss of the kidney resulted in a decrease of 12.0% (5.8 ml/(min×1.96 m 2 )) of GFR, while the ischemic injury resulted in a decrease of 6.5% (2.5 ml/(min×1.96 m 2 )) of GFR. The volume saved from the ipsilateral kidney was 87.1 (12.9) % (range: 27.0% to 131.7%). Recovery from ischemia was 93.5 (17.5) % (range:44.3% to 178.3%). In multivariate analysis, GFR preservation of the ipsilateral kidney was significantly correlated with the volume saved of the ipsilateral kidney ( β =0.383, 95% CI : 0.144 to 0.622, P =0.002). It was not related to the ischemia time ( β =0.046, 95% CI :-0.383 to 0.475, P =0.831). Conclusion: In the condition of limited ischemic time, in the short term ipsilateral renal function after partial nephrectomy is mainly determined by the loss of kidney volume, while ischemic injury only plays a minor role.

Background: Livers from controlled donation after circulatory death (cDCD) with very prolonged warm ischemic time (WIT) are regularly transplanted after abdominal normothermic regional perfusion (aNRP) plus ex-situ machine perfusion (MP). Considering aNRP as in-situ MP, we investigated whether the results of a pilot experience of extended criteria cDCD liver transplantation (LT) with prolonged WIT, with aNRP alone, were comparable to the best possible outcomes in low-risk cDCD LT., Methods: Prospectively collected data on 24 cDCD LT, with aNRP alone, were analyzed., Results: The median total and asystolic WIT were 51 and 25 min. Measures within benchmark cut-offs were: median duration of surgery (5.9 h); median intraoperative transfusions (3 units of red blood cells); need for renal replacement therapy (2/24 patients); median intensive care stay (3 days); key complications; overall morbidity, graft loss, and retransplantation up to 12 months; 12-month mortality (2/21 patients). The median hospital stay (33 days, due to logistics) and mortality up to 6 months (2/24 patients, due to graft-unrelated causes) exceeded benchmark thresholds., Conclusions: This pilot experience suggests that livers from cDCD with very prolonged WIT that appear viable during adequate quality aNRP may be safely transplanted, with no need for ex-situ MP, with considerable resource savings., (Copyright © 2023 International Hepato-Pancreato-Biliary Association Inc. Published by Elsevier Ltd. All rights reserved.)

The donor operation and the hemodynamics during declaration resulting in donor warm ischemia time have been linked to the outcomes in donation after circulatory death (DCD) liver transplantation (LT). Scrutiny of the donor hemodynamics at the time of withdrawal of life support concluded that a functional donor warm ischemia time may be associated with LT graft failure. Unfortunately, the definition for functional donor warm ischemia time has not reached a consensus-but has almost always incorporated time spent in a hypoxic state. Herein, we reviewed 1114 DCD LT cases performed at the 20 highest volume centers during 2014 and 2018. Donor hypoxia began within 3 minutes of withdrawal of life support for 60% of cases and within 10 minutes for 95% of cases. Graft survival was 88.3% at 1 year and 80.3% at 3 years. Scrutinizing the time spent under hypoxic conditions (oxygen saturation ≤ 80%) during the withdrawal of life support, we found an increasing risk of graft failure as hypoxic time increased from 0 to 16 minutes. After 16 minutes and up to 50 minutes, we did not find any increased risk of graft failure. In conclusion, after 16 minutes of time in hypoxia, the risk of graft failure in DCD LT did not increase. The current evidence suggests that an over-reliance on hypoxia time may lead to an unnecessary increase in DCD liver discard and may not be as useful for predicting graft loss after LT., (Copyright © 2023 American Association for the Study of Liver Diseases.)

Objective: To identify factors associated with longitudinal ipsilateral functional decline after partial nephrectomy (PN)., Patients and Methods: Of 1140 patients managed with PN (2012-2014), 349 (31%) had imaging/serum creatinine levels pre-PN, 1-12 months post-PN (new baseline), and >3 years later necessary for inclusion. Parenchymal-volume analysis was used to determine split renal function. Patients were grouped as having significant renal comorbidity (Cohort SRC : diabetes mellitus with insulin-dependence or end-organ damage, refractory hypertension, or severe pre-existing chronic kidney disease) vs not having significant renal comorbidity (Cohort NoSRC ) preoperatively. Multivariable regression was used to identify predictors of annual ipsilateral parenchymal atrophy and functional decline relative to new baseline values post-PN, after the kidney had healed., Results: The median follow-up was 6.3 years with 87/226/36 patients having cold/warm/zero ischaemia. The median cold/warm ischaemia times were 32/22 min. Overall, the median tumour size was 3.0 cm. The preoperative glomerular filtration rate (GFR) and new baseline GFR (NBGFR) were 81 and 71 mL/min/1.73 m 2 , respectively. After establishment of the NBGFR, the median loss of global and ipsilateral function was 0.7 and 0.4 mL/min/1.73 m 2 /year, respectively, consistent with the natural ageing process. Overall, the median ipsilateral parenchymal atrophy was 1.2 cm 3 /year and accounted for a median of 53% of the annual functional decline. Significant renal comorbidity, age, and warm ischaemia were independently associated with ipsilateral parenchymal atrophy (all P < 0.01). Significant renal comorbidity and ipsilateral parenchymal atrophy were independently associated with annual ipsilateral functional decline (both P < 0.01). Annual median ipsilateral parenchymal atrophy and functional decline were both significantly increased for Cohort SRC compared to Cohort NoSRC (2.8 vs 0.9 cm 3 , P < 0.01 and 0.90 vs 0.30 mL/min/1.73 m 2 /year, P < 0.01, respectively)., Conclusions: Longitudinal renal function following PN generally follows the normal ageing process. Significant renal comorbidities, age, warm ischaemia, and ipsilateral parenchymal atrophy were the most important predictors of ipsilateral functional decline following establishment of NBGFR., (© 2023 The Authors. BJU International published by John Wiley & Sons Ltd on behalf of BJU International.)

Objective: To quantificationally illustrate the impact of ischemia time (IT) on renal function decline after partial nephrectomy (PN), especially for patients with compromised baseline renal function (estimated glomerular filtration rate [eGFR] < 90 mL/min/1.73 m 2 )., Methods: Patients undergoing PN during 2014-2021 from a prospectively maintained database were reviewed. Propensity score matching (PSM) was employed to balance the possible covariates between patients with or without baseline compromised renal function. Specifically, the relationship of IT with postoperative renal function was illustrated. Two machine learning methods (logistic least absolute shrinkage and selection operator [LASSO] logistic regression and random forest) were applied to quantify the relative impact of each covariables., Results: The average drop percent of eGFR was -10.9% (- 12.2%, - 9.0%). Multivariable Cox proportional regression and linear regression analyses identified five risk factors for renal function decline, namely RENAL Nephrometry Score (RNS), age, baseline eGFR, diabetes and IT (all p < 0.05). Specifically, the relationship of IT with postoperative functional decline emerged as non-linear, with an increase from 10-30 min and a plateau afterwards among patients with normal function (eGFR ≥ 90 mL/min/1.73 m 2 ), whereas with an increase from 10 to 20 min and a plateau afterwards among patients with compromised function (eGFR < 90 mL/min/1.73 m 2 ). Furthermore, the coefficient's path and random forest analysis revealed that the top two most important features were RNS and age., Conclusion: IT exhibits the secondarily non-linear relationship with postoperative renal function decline. Patients with compromised baseline renal function are less tolerant to ischemia damage. The use of a single cut-off interval of IT in the setting of PN is flawed., (© 2023. The Author(s), under exclusive licence to Springer Nature B.V.)

Background: Kidney transplantation is the current optimal treatment for suitable patients with end-stage renal disease. The second warm ischemic time (SWIT) is known to negatively impact delayed graft function, and long-term graft survival, and methods are required to ameliorate the impacts of SWIT on transplantation outcomes., Materials and Methods: This study primarily focused on determining the effect of a novel thermally insulating jacket on the thermal profile of the human kidney and quantifying the reduction in thermal energy experienced using this device (KPJ™). An ex vivo simulated transplantation model was developed to determine the thermal profiles of non-utilized human kidneys with and without KPJ™ (n = 5). Control kidney temperature profiles were validated against the temperature profiles of n = 10 kidneys during clinical kidney transplantation., Results: Using the ex-vivo water bath model, the thermally insulated human kidney reached the 15°C metabolic threshold temperature at 44.5 ± 1.9 min (vs control: 17.3 ± 1.8 min (p = 0.00172)) and remained within the 18°C threshold until 53.3 ± 1.3 min (vs control: 20.9 ± 2.0 min (p = 0.002)). The specific heat capacity of KPJ™ protected kidney was four-fold compared to the control kidney. The clinical temperature audit, closely correlated with the water bath model, hence validating this ex-vivo human kidney transplant model., Conclusion: Intraoperative thermal protection is a simple and viable method of reducing the thermal injury that occurs during the SWIT and increasing the specific heat capacity of the system. Such technology could easily be translated into clinical kidney transplant practice., (© 2022 The Authors. Artificial Organs published by International Center for Artificial Organ and Transplantation (ICAOT) and Wiley Periodicals LLC.)

Background: In kidney transplantation (KT), efforts to minimize rewarming and optimize anastomosis time during vascular anastomosis improve graft outcomes. We recently reported the safety and efficacy of a pouch-type thermal barrier bag (TBB) made of elastomer gel to reduce second-warm ischemic injury during vascular anastomosis. We aimed to examine the usefulness of the TBB in prolonged vascular anastomosis in KT performed by young transplant fellows., Methods: Young transplant fellows performed KT under the supervision of certified transplant surgeons. The kidney graft was placed inside the TBB with an outlet for vessels and preserved during vascular anastomosis. A non-contact infrared thermometer measured the graft surface temperature before and after vascular anastomosis. After completion of the anastomosis, the TBB was manually slid out of the transplanted kidney and removed before graft reperfusion. Clinical data, including patient characteristics and perioperative variables, were collected. The primary endpoint was the median graft surface temperature at the end of the anastomosis., Results: Ten living-donor kidney transplant recipients with a median age of 56.5 years (range, 40-69 years) underwent KT procedures performed by young transplant fellows. The median anastomosis time was 53 (43-67) min. At the end of anastomosis, the median graft surface temperature was 17.7°C (16.3-18.3°C); no serious adverse events or delayed graft function were observed., Conclusion: The TBB can keep transplanted kidneys at a low temperature even with prolonged vascular anastomosis time, thus contributing to the functional preservation of transplanted kidneys and stable transplant outcomes., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: Second warm ischemia (SWI) injury between the completion of vascular anastomosis and graft reperfusion has been a longstanding issue in organ transplantation. This type of SWI injury is more severe in transplanted organs more sensitive to temperature changes. This study aimed to present the newly developed OrganPocket, an organ protector made from a proprietary elastomer material, and to demonstrate its efficacy in mitigating SWI injury in clinical kidney transplantation., Methods: We used an ex vivo porcine organ model to evaluate OrganPocket. After removal, donor organs were immersed and cryopreserved in an organ preservation solution at 4°C before being placed in an OrganPocket. The organ graft and OrganPocket were held for 30 minutes in a 37°C environment mimicking intra-abdominal conditions while temperatures were recorded. Control organs were evaluated under the same conditions without an OrganPocket. In addition, we tested OrganPocket in an intra-abdominal porcine allograft transplant model., Results: The control organ group temperature reached ≥16°C after 30 minutes, while the mean core temperature in the OrganPocket organ group remained at no more than 10°C. Despite an SWI time of approximately 30 minutes, the surface organ temperature upon removal of OrganPocket was 20°C. Cardiac grafts also exhibited a normal heartbeat after reperfusion., Conclusions: OrganPocket is the world's first device designed to prevent SWI and should also prove useful for heart transplantation., Competing Interests: DISCLOSURES The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background: Hepatocyte transplantation has been reported to be useful for metabolic diseases and acute liver failure. However, the shortage of donors limits its widespread use. The use of livers from donors after circulatory death, which are currently unavailable for liver transplantation, may alleviate donor shortage. In this study, we investigated the effects of mechanical perfusion on cardiac arrest hepatocytes in a rat model using cardiac arrest donor livers, and we evaluated the function of cardiac arrest hepatocytes., Methods: F344 rat hepatocytes isolated from livers removed during cardiac pulsation were compared with those isolated from livers removed after 30 minutes of warm ischemia after cardiac arrest. We then compared hepatocytes isolated from livers removed after 30 minutes of warm ischemia with those isolated after 30 minutes of mechanical perfusion before isolation. The yield per liver weight, ammonia removal capacity, and adenosine diphosphate/adenosine triphosphate ratio were evaluated., Results: Thirty minutes of warm inhibition reduced hepatocyte yield but did not alter ammonia removal capacity and energy status. Mechanical perfusion increased hepatocyte yield and improved the adenosine diphosphate/adenosine triphosphate ratio after 30 minutes of warm inhibition., Conclusion: Thirty minutes of warm ischemic time may decrease isolated hepatocyte yield without degrading their function. If increased yields are obtained, livers from donors dying of cardiac arrest could be used for hepatocyte transplantation. The results also suggest that mechanical perfusion may positively affect the energy status of hepatocytes., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Objectives: To evaluate the differences in baseline chronic kidney disease (CKD) status in correlations between warm ischemic time (WIT) and acute kidney injury (AKI) or acute/chronic renal function change after robot-assisted partial nephrectomy (RAPN). Methods: This study retrospectively recruited 1290 patients from a multi-institutional RAPN database. The patients were grouped into four preoperative CKD categories: CKD Group 1 (CKDG1), CKD Group 2 (CKDG2), CKD Group 3a (CKDG3a), and CKD Group 3b (CKDG3b). The correlation between WIT and the probability of AKI was assessed according to the baseline CKD grade, together with changes in serum creatinine (sCr) at the postoperative maximum and chronic renal function. Results: AKI was not observed in the CKDG1 group. The probability of AKI at WIT = 30 minutes was 5.6% for CKDG2, 8.5% for CKDG3a, and 11.6% for CKDG3b (all p  < 0.05). WIT was an independent predictor of AKI occurrence in the multivariate model for these three CKD groups. Significant weak correlations were observed between WIT and sCr change for all four groups, with R 2  = 0.22 for CKDG1, R 2  = 0.16 for CKDG2, R 2  = 0.03 for CKDG3a, and R 2  = 0.09 for ≥CKDG3b. For chronic renal function, correlations were significant in CKDG2, CKDG3a, and ≥CKDG3b, yet R 2 was considered small in all cases (<0.1). Conclusions: The association between extended WIT and the probability of AKI increased in patients with more severe baseline CKD. The correlation between WIT and renal function was significant, yet clinically modest.

Objective: To provide a narrative review of the major advances regarding ischaemia and functional recovery after partial nephrectomy (PN), along with the ongoing controversies., Methods: Key articles reflecting major advances regarding ischaemia and functional recovery after PN were identified. Special emphasis was placed on contributions that changed perspectives about surgical management. Priority was also placed on randomized trials of off-clamp vs on-clamp cohorts., Results: A decade ago, 'Every minute counts' was published, showing strong correlations between duration of ischaemia and development of acute kidney injury (AKI) and chronic kidney disease after clamped PN. This reinforced perspectives that ischaemia was the main modifiable factor that could be addressed to improve functional outcomes and helped spur efforts towards reduced or zero ischaemia PN. These approaches were associated with strong functional recovery and some peri-operative risk, although they were generally safe in experienced hands. Further research demonstrated that, when parenchymal volume changes were incorporated into the analyses, ischaemia lost statistical significance, and percent parenchymal volume saved proved to be the main determinant. Cold ischaemia was confirmed to be highly protective, and limited warm ischaemia also proved to be safe. The reconstructive phase of PN, with avoidance of parenchymal devascularization, appears to be most important for functional outcomes. Randomized trials of on-clamp vs off-clamp PN have shown minimal impact of ischaemia on functional recovery., Conclusions: The past decade has witnessed great progress regarding functional recovery after PN, with many lessons learned. However, there are still unanswered questions, including: What is the threshold of warm ischaemia at which irreversible ischaemic injury begins to develop? Are some cohorts at increased risk for AKI or irreversible ischaemic injury? and Which patients should be prioritized for zero-ischaemia PN?, (© 2022 The Authors. BJU International published by John Wiley & Sons Ltd on behalf of BJU International.)

To expand the pool of organs, hypothermic oxygenated perfusion (HOPE), one of the most promising perfusion protocols, is currently performed after cold storage (CS) at transplant centers (HOPE-END). We investigated a new timing for HOPE, hypothesizing that performing HOPE before CS (HOPE-PRE) could boost mitochondrial protection allowing the graft to better cope with the accumulation of oxidative stress during CS. We analyzed liver injuries at 3 different levels. Histologic analysis demonstrated that, compared to classical CS (CTRL), the HOPE-PRE group showed significantly less ischemic necrosis compared to CTRL vs HOPE-END. From a biochemical standpoint, transaminases were lower after 2 hours of reperfusion in the CTRL vs HOPE-PRE group, which marked decreased liver injury. qPCR analysis on 37 genes involved in ischemia-reperfusion injury revealed protection in HOPE-PRE and HOPE-END compared to CTRL mediated through similar pathways. However, the CTRL vs HOPE-PRE group demonstrated an increased transcriptional level for protective genes compared to the CTRL vs HOPE-END group. This study provides insights on novel biomarkers that could be used in the clinic to better characterize graft quality improving transplantation outcomes., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Purpose of Review: This review describes recent developments in the field of liver perfusion techniques., Recent Findings: Dynamic preservation techniques are increasingly tested due to the urgent need to improve the overall poor donor utilization. With their exposure to warm ischemia, livers from donors after circulatory death (DCD) transmit additional risk for severe complications after transplantation. Although the superiority of dynamic approaches compared to static-cold-storage is widely accepted, the number of good quality studies remains limited. Most risk factors, particularly donor warm ischemia, and accepted thresholds are inconsistently reported, leading to difficulties to assess the impact of new preservation technologies. Normothermic regional perfusion (NRP) leads to good outcomes after DCD liver transplantation, with however short ischemia times. While randomized controlled trials (RCT) with NRP are lacking, results from the first RCTs with ex-situ perfusion were reported. Hypothermic oxygenated perfusion was shown to protect DCD liver recipients from ischemic cholangiopathy. In contrast, endischemic normothermic perfusion seems to not impact on the development of biliary complications, although this evidence is only available from retrospective studies., Summary: Dynamic perfusion strategies impact posttransplant outcomes and are increasingly commissioned in various countries along with more evidence from RCTs. Transparent reporting of risk and utilization with uniform definitions is required to compare the role of different preservation strategies in DCD livers with prolonged ischemia times., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Background: The impact of warm ischemia time (WIT) on renal functional recovery remains controversial. We examined the length of WIT>30 min on the long-term renal function following on-clamp partial nephrectomy (PN)., Methods: Data from 23 centers for patients undergoing on-clamp PN between 2000 and 2018 were analyzed. We included patients with two kidneys, single tumor, cT1, minimum 1-year follow-up, and preoperative eGFR≥60 mL/min/1.73m 2 . Patients were divided into two groups according to WIT length: group I "WIT≤30 min" and group II "WIT>30 min." A propensity-score matched analysis (1:1 match) was performed to eliminate potential confounding factors between groups. We compared eGFR values, eGFR (%) preservation, eGFR decline, events of chronic kidney disease (CKD) upgrading, and CKD-free progression rates between both groups. Cox regression analysis evaluated WIT impact on upgrading of CKD stages., Results: The primary cohort consisted of 3526 patients: group I (N.=2868) and group II (N.=658). After matching the final cohort consisted of 344 patients in each group. At last follow-up, there were no significant differences in median eGFR values at 1, 3, 5, and 10 years (P>0.05) between the matched groups. In addition, the median eGFR (%) preservation and absolute eGFR change were similar (89% in group I vs. 87% in group II, P=0.638) and (-10 in group I vs. -11 in group II, P=0.577), respectively. The 5 years new-onset CKD-free progression rates were comparable in the non-matched groups (79% in group I vs. 81% in group II, log-rank, P=0.763) and the matched groups (78.8% in group I vs. 76.3% in group II, log-rank, P=0.905). Univariable Cox regression analysis showed that WIT>30 min was not a predictor of overall CKD upgrading (HR:0.953, 95%CI 0.829-1.094, P=0.764) nor upgrading into CKD stage ≥III (HR:0.972, 95%CI 0.805-1.173, P=0.764). Retrospective design is a limitation of our study., Conclusions: Our analysis based on a large multicenter international cohort study suggests that WIT length during PN has no effect on the long-term renal function outcomes in patients having two kidneys and preoperative eGFR≥60 mL/min/1.73m 2 .

Competing Interests: The authors declare no conflicts of interest.

Background: Toward the goal of using more livers for transplantation, transplant centers are looking to increase the use of organs from "marginal" donors. Livers from these donors, however, have been shown to be more susceptible to preservation and reperfusion injury., Methods: Using a porcine model of donation after circulatory death, we studied the use of antibody-mediated CD47 blockade to further improve liver graft function undergoing normothermic machine perfusion. Livers from 20 pigs (5 per group) were brought under either 30 or 60 min of warm ischemia time followed by the administration of CD47 monoclonal antibody (CD47mAb) treatment or immunoglobulin G control antibodies and 6 h of normothermic extracorporeal liver perfusion., Results: After 6 h of normothermic extracorporeal liver perfusion, CD47mAb-treated livers with 30 or 60 min warm ischemia time had significantly lower alanine transaminase levels and higher bile production compared with their respective control groups. Blockade of the CD47 signaling pathway resulted in significantly lower thrombospondin-1 protein levels, lower expression of caspase-3, and higher expression of phosphorylated extracellular signal-regulated kinase., Conclusions: These findings suggested that CD47mAb treatment decreases ischemia/reperfusion injury through CD47/thrombospondin-1 signaling downregulation and the presence of necrosis/apoptosis after reperfusion and could increase liver regeneration during normothermic perfusion of the liver., Competing Interests: W.C.C. is a founder of Pathfinder Therapeutics and an advisory board member of Novartis Pharmaceutical. P.M. is an employee and stockholder of Arch Oncology. The other authors declare no conflicts of interest., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Objectives: To evaluate the association between extended (≥30 min) warm ischemic time and renal function in patients undergoing robot-assisted partial nephrectomy., Methods: This multi-institutional study retrospectively recruited 1131 patients who underwent robot-assisted partial nephrectomy. Patients were classified into shorter (<30 min; n = 1038) and longer (≥30 min; n = 92) groups based on the ischemic time required, and 1:2 propensity score matching was used to minimize selection bias. The perioperative outcomes, including acute kidney injury and trifecta attainment, and mid/long-term renal function were assessed before and after matching., Results: Patients in the longer group had tumors with a significantly larger diameter and RENAL nephrometry score. The decline in the nadir of the estimated glomerular filtration rate was significantly greater in the longer than the shorter group in the unmatched and matched cohorts (-16.2 vs -5.5%, P < 0.001; 15.5 vs -9.5%, P = 0.003, respectively). A higher incidence of acute kidney injury (9.8 vs 2.6%, P = 0.002) was observed in the longer group before matching, whereas the difference was comparable after matching. Before matching, the decline in estimated glomerular filtration rate at 6 months postoperatively was greater (-8.2 vs -5.1%, P = 0.005) and trifecta attainment was lower (50.0 vs 63.5%, P < 0.001) in the longer group. However, the differences were comparable for both the parameters between the groups in the matched cohort., Conclusions: While extended warm ischemia during robot-assisted partial nephrectomy can be demanded in case of large and complex tumors, its impact on postoperative renal function is limited., (© 2021 The Japanese Urological Association.)

Background: Uncontrolled donation after circulatory death (DCD) donors are an extraordinary resource to increase the number of lungs available for transplantation. However, the risk of the warm ischemia resulting from cardiac arrest to irreversibly damage the organs is considerable. Moreover, graft preservation issues and organizational problems often worsen the dangerous effects of warm ischemia. Ex vivo lung perfusion (EVLP) enables us to evaluate and recondition lungs whose functionality is doubtful, as well as to overcome the difficulties related to time and logistics., Methods: We report the case of uncontrolled DCD lungs successfully treated with an exceptionally prolonged EVLP. Because the donor's blood count and liver biopsy showed signs of possible leukemia, EVLP was protracted up to 17 h while waiting for immunohistochemical analyses to rule out this diagnosis; eventually, the results came back negative, and the lungs were judged suitable for transplantation., Results: The recipient was a 32-y-old male individual with cystic fibrosis, colonized by Pandoraea pnomenusa. Bilateral transplantation required central extracorporeal membrane oxygenation. The patient was extubated after 36 h and was discharged 21 d after the operation. Despite early recolonization by Pandoraea pnomenusa and airway complications requiring pneumatic dilatation, he is alive and has a satisfactory respiratory function 15 mo after transplantation., Conclusions: Uncontrolled DCD represents a challenge due to both logistical issues and the complexity of graft evaluation before procurement. EVLP with cellular perfusate could be a valuable tool to overcome these limits. Nonetheless, caution should be exercised when interpreting the effects of this technique on airway healing., Competing Interests: The authors declare no funding or conflicts of interest., (Copyright © 2021 The Author(s). Published by Wolters Kluwer Health, Inc.)

Background: Donation after circulatory death (DCD) in Italy, given its 20-min stand-off period, provides a unique bench test for normothermic regional perfusion (NRP) and dual hypothermic oxygenated machine perfusion (D-HOPE)., Methods: We coordinated a multicenter retrospective Italian cohort study with 44 controlled DCD donors, who underwent NRP, to present transplant characteristics and results. To rank our results according to the high donor risk, we matched and compared a subgroup of 37 controlled DCD livers, preserved with NRP and D-HOPE, with static-preserved controlled DCD transplants from an established European program., Results: In the Italian cohort, D-HOPE was used in 84% of cases, and the primary nonfunction rate was 5%. Compared with the matched comparator group, the NRP + D-HOPE group showed a lower incidence of moderate and severe acute kidney injury (stage 2: 8% versus 27% and stage 3: 3% versus 27%; P = 0.001). Ischemic cholangiopathy remained low (2-y proportion free: 97% versus 92%; P = 0.317), despite the high-risk profile resulting from the longer donor warm ischemia in Italy (40 versus 18 min; P < 0.001)., Conclusions: These data suggest that NRP and D-HOPE yield good results in DCD livers with prolonged warm ischemia., Competing Interests: The authors declare no funding or conflicts of interest., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Liver ischemia reperfusion injury (LIRI) often occurs during liver transplantation, resection, and various circulatory shock procedures, leading to severe metabolic disorders, inflammatory immune responses, oxidative stress injury, and cell apoptosis. Methyl eugenol (ME) is structurally similar to eugenol and has anti-inflammatory and apoptotic pharmacological effects. However, whether ME protects the liver from LIRI damage requires further investigation., Methods: We established a partially warm LIRI model by subjecting C57BL/6J mice to 60 min of ischemia, followed by reperfusion for 6 h. We also established a hypoxia-reoxygenation injury (H/R) cell model by subjecting AML12 (a mouse liver cell line) cells to 24 h hypoxia, followed by 18 h normoxia. The extent of liver injury was assessed by serum transaminase concentrations, hematoxylin and eosin staining, quantitative real-time PCR, myeloperoxidase activity, and TUNEL analysis. Apoptosis was detected using flow cytometry. The protein levels of p-PI3K, PI3K, p-Akt, Akt, p-Bad, Bad, Bcl-2, Bax, and cleaved caspase-3 were detected by western blotting. LY294002, an inhibitor of PI3K/Akt signaling, was used to elucidate the relationship between ME and PI3K/Akt signaling., Results: ME successfully alleviated LIRI-induced liver injury, inflammatory response, and apoptosis induced, as well as liver cell injury induced by hypoxia reoxygenation. ME is known to activate the PI3K/Akt signaling pathway in hepatocyte injury in vivo and in vitro, and when this signaling pathway is inhibited, the protective effect of ME is abrogated., Conclusions: The use of ME is a potential therapeutic approach for regulating LIRI by activating PI3K/Akt signaling., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Kidney transplantation with grafts procured after donation-after-cardiac death (DCD) has led to an increase in incidence of delayed graft function (DGF). It is thought that the warm ischemic (WI) insult encountered during DCD procurement is the cause of this finding, although few studies have been designed to definitely demonstrate this causation in a transplantation setting. Here, we use a large animal renal transplantation model to study the effects of prolonged WI during procurement on post-transplantation renal function. Kidneys from 30 kg-Yorkshire pigs were procured following increasing WI times of 0 min (Heart-Beating Donor), 30 min, 60 min, 90 min, and 120 min (n = 3-6 per group) to mimic DCD. Following 8 h of static cold storage and autotransplantation, animals were followed for 7-days. Significant renal dysfunction (SRD), resembling clinical DGF, was defined as the development of oliguria < 500 mL in 24 h from POD3-4 along with POD4 serum potassium > 6.0 mmol/L. Increasing WI times resulted in incremental elevation of post-operative serum creatinine that peaked later. DCD120min grafts had the highest and latest elevation of serum creatinine compared to all groups (POD5: 19.0 ± 1.1 mg/dL, p < 0.05). All surviving animals in this group had POD4 24 h urine output < 500 cc (mean 235 ± 172 mL) and elevated serum potassium (7.2 ± 1.1 mmol/L). Only animals in the DCD120min group fulfilled our criteria of SRD (p = 0.003), and their renal function improved by POD7 with 24 h urine output > 500 mL and POD7 serum potassium < 6.0 mmol/L distinguishing this state from primary non-function. In a transplantation survival model, this work demonstrates that prolonging WI time similar to that which occurs in DCD conditions contributes to the development of SRD that resembles clinical DGF., (© 2021. The Author(s).)

Heart transplantation is a lifesaving procedure, which is limited by the availability of donor hearts. Using hearts from donors after circulatory death, which have sustained global ischemia, requires thorough studies on reliable and reproducible models that developing researchers may not have mastered. By combining the most recent literature and our recommendations based on observations and trials and errors, the methods here detail a sound in vivo heterotopic heart transplantation model for rats in which protective interventions on the ischemic heart can be studied, and thus allowing the scientific community to advance organ preservation research. Knowledge gathered from reproducible animal models allow for successful translation to clinical studies., Competing Interests: The authors have no conflicts of interest to declare that compromise the quality of this article., (© 2021 The Authors. Animal Models and Experimental Medicine published by John Wiley & Sons Australia, Ltd on behalf of The Chinese Association for Laboratory Animal Sciences.)

Donation after circulatory death (DCD) grafts are commonly used in liver transplantation. Attributable to the additional ischemic event during the donor warm ischemia time (DWIT), DCD grafts carry an increased risk for severe ischemia/reperfusion injury and postoperative complications, such as ischemic cholangiopathy. The actual ischemia during DWIT depends on the course of vital parameters after withdrawal of life support and varies widely between donors. The ischemic period (functional DWIT) starts when either Spo2 or blood pressure drop below a certain point and lasts until the start of cold perfusion during organ retrieval. Over the years, multiple definitions and thresholds of functional DWIT duration have been used. The International Liver Transplantation Society organized a Consensus Conference on DCD, Liver Preservation, and Machine Perfusion on January 31, 2020 in Venice, Italy. The aim of this conference was to reach consensus about various aspects of DCD liver transplantation in context of currently available evidence. Here we present the recommendations with regards to the definitions used for DWIT and functional DWIT, the importance of vital parameters after withdrawal of life support, and acceptable thresholds of duration of functional DWIT to proceed with liver transplantation., Competing Interests: The authors declare no funding or conflicts of interest., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Kidney transplantation is the optimum treatment for kidney failure in carefully selected patients. Technical surgical complications and second warm ischemic time (SWIT) increase the risk of delayed graft function (DGF) and subsequent short- and long-term graft outcomes including the need for post-transplant dialysis and graft failure. Intraoperative organ thermal regulation could reduce SWIT, minimizing surgical complications due to time pressure, and limiting graft ischemia-reperfusion injury., Methods: A novel ischemic-injury thermal protection jacket (iiPJ) was designed and fabricated in silicone composite and polyurethane (PU) elastomer prototypes. Both were compared with no thermal insulation as controls. Time to reach ischemic threshold (15°C) and thermal energy transfer were compared. A water bath model was used to examine the thermal protective properties of porcine kidneys, as a feasibility study prior to in vivo translation., Results: In both iterations of the iiPJ, the time taken to reach the warm ischemia threshold was 35.2 ± 1.4 minutes (silicone) and 38.4 ± 3.1 minutes (PU), compared with 17.2 ± 1.5 minutes for controls (n = 5, P < .001 for both comparisons). Thermal energy transfer was also found to be significantly less for both iiPJ variants compared with controls. There was no significant difference between the thermal performance of the 2 iiPJ variants., Conclusion: Protection from SWIT by using a protective insulation jacket is feasible. With clinical translation, this novel strategy could facilitate more optimal surgical performance and reduce transplanted organ ischemia-reperfusion injury, in particular the SWIT, potentially affecting delayed graft function and long-term outcomes., (Copyright © 2021 Elsevier Inc. All rights reserved.)

In donation after circulatory death heart transplantation, the donor heart is exposed to circulatory load. The right ventricle, due to its structure, has high compliance for volume load but is particularly vulnerable to increased pressure load. This study used a porcine model to conduct a functional assessment of the hemodynamics of the heart, with a focus on the right ventricle. Six pigs weighing 24.6 ± 1.4 kg were used. Circulatory death was induced by asphyxiation after median sternotomy. After 30 minutes in the state of global warm ischemia, the ascending aorta was clamped, followed by a 20-minute reperfusion of the heart with a 20°C blood cardioplegia solution. Systemic circulation was established by cardiopulmonary bypass after aortic cross-clamping. After initial reperfusion, the blood cardioplegia solution was replaced with blood. The blood was then rewarmed while the heart was still in a non-working state. Cardiac function was assessed twice in situ, first by the thermodilution method, and then, by the pressure-volume measurement both at preischemia and at three hours after initiation of reperfusion. The recovery rate of cardiac output was 75%. End-systolic elastance (P = .02) and pulmonary arterial elastance significantly increased (P = .03), but the ratio of arterial elastance to end-systolic elastance was preserved (P = .91) in the right ventricle. Despite a decrease in cardiac output after reperfusion from warm ischemia, the right ventricle had a potential to respond the elevated afterload. It is important that donations after circulatory death heart transplantation should be performed with attention to avoiding right ventricular distension., (© 2020 International Center for Artificial Organs and Transplantation and Wiley Periodicals LLC.)

Chronic kidney disease is the most common type of organ failure worldwide, with a prevalence of 13.4% for all stages. Organ transplant is the only curative option for end-stage kidney failure. However, the shortage of organ donors remains a major obstacle in organ transplant, with donation after circulatory death being the most viable path to increasing the donor pool. The circumstances that surround this type of donation are different from donation after brain death, namely concerning warm ischemia times, which are longer and may preclude a successful transplant. This article describes the pathophysiology of warm ischemia and summarizes recent developments in technological and methodological practices that mitigate the mechanisms of warm ischemia. Anoxia, mitochondrial dysfunction, calcium overload, oxidative and nitrosative stress, immune response, and no reflow are the main mechanisms by which ischemia leads to cell death and organ dysfunction. In situ oxygenated recirculation, abdominal normothermic organ recirculation, abdominal hypothermic organ recirculation, and ex vivo machine perfusion ensure continued organ perfusion and prevent prolonged warm ischemia in organ donation. These practices, coupled with optimizations in the identification and assessment of potential donors after circulatory death, may lead to a significant increase in the number and success rates of organ transplant worldwide.

We previously demonstrated that the blockade of mGluR5 by 2-methyl-6(phenylethynyl)pyridine (MPEP) reduces both cold and warm ischemia/reperfusion injury. Here we evaluated whether MPEP reduces the hepatic preservation injury in rat livers from cardiac-death-donors (DCDs). Livers from DCD rats were isolated after an in situ warm ischemia (30 min) and preserved for 22 h at 4 °C with UW solution. Next, 10 mg/Kg MPEP or vehicle were administered 30 min before the portal clamping and added to the UW solution (3 µM). LDH released during washout was quantified. Liver samples were collected for iNOS, eNOS, NO, TNF-α, ICAM-1, caspase-3 and caspase-9 protein expression and nuclear factor-erythroid-2-related factor-2 (Nrf2) gene analysis. Lower LDH levels were detected in control grafts versus DCD groups. An increase in eNOS and NO content occurred after MPEP treatment; iNOS and TNF-α content was unchanged. ICAM-1 expression was reduced in the MPEP-treated livers as well as the levels of caspase-3 and caspase-9. Nrf2, oxidative stress-sensitive gene, was recovered to control value by MPEP. These results suggest that MPEP can be used to reclaim DCD livers subjected to an additional period of cold ischemia during hypothermic storage. MPEP protects against apoptosis and increased eNOS, whose overexpression has been previously demonstrated to be protective in hepatic ischemia/reperfusion damage.

Metformin may act renoprotective prior to kidney transplantation by reducing ischemia-reperfusion injury (IRI). This study examined whether metformin preconditioning and postconditioning during ex vivo normothermic machine perfusion (NMP) of rat and porcine kidneys affect IRI. In the rat study, saline or 300 mg/kg metformin was administered orally twice on the day before nephrectomy. After 15 minutes of warm ischemia, kidneys were preserved with static cold storage for 24 hours. Thereafter, 90 minutes of NMP was performed with the addition of saline or metformin (30 or 300 mg/L). In the porcine study, after 30 minutes of warm ischemia, kidneys were preserved for 3 hours with oxygenated hypothermic machine perfusion. Subsequently, increasing doses of metformin were added during 4 hours of NMP. Metformin preconditioning of rat kidneys led to decreased injury perfusate biomarkers and reduced proteinuria. Postconditioning of rat kidneys resulted, dose-dependently, in less tubular cell necrosis and vacuolation. Heat shock protein 70 expression was increased in metformin-treated porcine kidneys. In all studies, creatinine clearance was not affected. In conclusion, both metformin preconditioning and postconditioning can be done safely and improved rat and porcine kidney quality. Because the effects are minor, it is unknown which strategy might result in improved organ quality after transplantation., (© 2020 The Authors. Clinical and Translational Science published by Wiley Periodicals LLC on behalf of the American Society for Clinical Pharmacology and Therapeutics.)

Background: In an experimental murine liver clamping model, we aimed to investigate the efficacy of real-time confocal microscopy (RCM) in assessing viability of steatotic livers in comparison to standard assessment tools, including histopathological evaluation., Methods: C57Bl/6 mice were subjected to a methionine-choline-deficient diet causing nonalcoholic fatty liver disease or to Lieber DeCarli diet causing ethanol-induced liver injury. Untreated animals served as controls. Liver biopsies were analyzed following challenge with 45 min of warm ischemia time and either 4 h of reperfusion or 24 h of cold storage. Organ quality assessment was performed at defined time points by RCM, histological staining, measurement of serum alanine aminotransferase activity, and expression analyses of proinflammatory cytokines. Additionally, survival analysis was performed., Results: Cold as well as warm ischemia time resulted in a significant decrease in cell viability when compared with naive livers as well as nonischemic-challenged steatotic livers (P < 0.05) as assessed by RCM. Furthermore, RCM revealed the actual cellular damage at early time points, while established methods including H&E-staining and serum transaminase profile failed., Conclusions: In a translational attempt, we demonstrate that RCM is a suitable diagnostic tool to obtain information about functional damage of the liver apart from standard approaches.

Background: Ischemia-reperfusion associated with prolonged warm ischemia during donation after circulatory death (DCD) induces acute lung injury. The objective of this study was to combine ex vivo lung perfusion (EVLP) and a heat shock protein-90 inhibitor (HSP90i) to recondition DCD organs and prevent primary graft dysfunction., Methods: Pigs (55 to 65 kg) were anesthetized, ventilated, and hemodynamically monitored. Cardiac arrest was induced with potassium chloride, and animals were left nonventilated for 2 hours. Lungs were procured and perfused in an EVLP platform for 4 hours by using a cellular perfusate. In the study group, the perfusate contained HSP90i and its transport vehicle (n = 4). In the control group, the perfusate contained only the transport vehicle (n = 4). Gas exchange, airway pressures, and compliance were measured. Pulmonary edema was assessed by bronchoscopy and weight measurement. Lung biopsy samples were obtained for histologic analyses and protein expression measurements., Results: The use of HSP90i reduced lung weight gain to 8.4 ± 3.4% vs 26.6 ± 6.2% in the control group (P < .05). There was reduced edema formation. The ratio of the partial pressure of arterial oxygen to the fraction of inspired oxygen at the end of EVLP was 423 ± 65 in the study group vs 339 ± 25 mm Hg in the control group, but this difference was not statistically significant. Lactate metabolism, pulmonary vascular resistance, and pulmonary arterial pressure improved during EVLP with the use of the HSP90i., Conclusions: The use of HSP90i with EVLP improves the lung reconditioning process. Further research is required to confirm whether these findings translate to benefit once transplanted and observed in vivo. Successful pharmacologic inhibitors may expand the donor pool in the context of DCD donors., (Copyright © 2020 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Background: Acute kidney injury (AKI) after liver transplantation is associated with increased morbidity and mortality. It remains controversial whether the choice of vena cava reconstruction technique impacts AKI., Methods: This is a single-center retrospective cohort of 897 liver transplants performed between June 2009 and September 2018 using either the vena cava preserving piggyback technique or caval replacement technique without veno-venous bypass or shunts. The association between vena cava reconstruction technique and stage of postoperative AKI was assessed using multivariable ordinal logistic regression. Causal mediation analysis was used to evaluate warm ischemia time as a potential mediator of this association., Results: The incidence of AKI (AKI stage ≥2) within 48 h after transplant was lower in the piggyback group (40.3%) compared to the caval replacement group (51.8%, P < 0.001). Piggyback technique was associated with a reduced risk of developing a higher stage of postoperative AKI (odds ratio, 0.49; 95% confidence interval, 0.37-0.65, P < 0.001). Warm ischemia time was shorter in the piggyback group and identified as potential mediator of this effect. There was no difference in renal function (estimated glomerular filtration rate and the number of patients alive without dialysis) 1 y after transplant., Conclusions: Piggyback technique, compared with caval replacement, was associated with a reduced incidence of AKI after liver transplantation. There was no difference in long-term renal outcomes between the 2 groups.

Background: Hepatic ischemia reperfusion injury often leads to increased complications and mortality after surgery. Although ischemic preconditioning is used as a convenient and effective method to protect the liver from warm ischemia reperfusion injury, the optimal protocol is currently unclear. Therefore, in this study, we sought to identify ideal conditions and methods for ischemic preconditioning. Materials and methods : We compared several preconditioning protocols of the ischemia/reperfusion (I/R) cycle in 30 male Sprague-Dawley rats (5 groups, n = 6), including relevant sham and I/R injury (no preconditioning) controls. Experimental group conditions included: (1) ischemia for 5 min/reperfusion for 10 min (ischemic preconditioning 1, IPC-1); (2) ischemia for 5 min/reperfusion for 5 min, repeated three times (IPC-2); and (3) ischemia for 10 min/reperfusion for 10 min (IPC-3). Readouts included transaminase activity levels measured from collected sera, and histopathological changes, liver cell apoptosis, superoxide dismutase (SOD) activity, glutathione (GSH) levels, and malondialdehyde (MDA) levels measured from collected liver tissue segments subjected to warm ischemia (that is from the 70% of the liver mass that had been deprived from blood flow during the ischemia phase). Results: Compared to the I/R control group, the IPC-1, IPC-2, and IPC-3 groups all showed significant decreases in liver transaminase activity levels, alleviation of pathological injury-associated changes, and a decrease in liver cell apoptosis. Moreover, SOD activity and GSH content were increased while MDA content was decreased in the three experimental groups. Compared to the IPC-1 and IPC-3 groups, the changes in the IPC-2 group were the most significant ( P  < 0.05). Conclusions: Ischemic preconditioning can reduce hepatic warm ischemia reperfusion injury in rats. The IPC-2 protocol, involving ischemia for 5 min and reperfusion for 5 min, repeated three times, provided the optimal protection against hepatic ischemia reperfusion injury among the protocols studied.

Objective: Tissue factor (TF) is a membrane component of many cells and a strong activator of blood coagulation. Damage to the cells induces an increase in its expression and concentration in blood plasma. The injury and breakdown of the cells is inseparably connected with the harvesting and preservation of the kidney., Purpose: The aim of the study was an analysis of TF in the renal vein after of restoration of circulation in the transplanted kidney. An additional goal was to investigate the impact of warm ischemia on TF., Materials and Methods: The examined group included 61 kidney recipients. Blood was taken from the renal vein in the first minute during reperfusion. Simultaneously, blood from a peripheral vein was also drawn. Apart from tissue factor (TF), I also examined thrombin/antithrombin complexes and fragments 1+2 of prothrombin., Results: In blood from renal veins, I noticed higher level of TF, thrombin/antithrombin complexes and fragments 1+2 of prothrombin in comparison with blood from peripheral veins (P < .0048, P < .016, P < .046, respectively). The 29 recipients (47% of the total) with postoperative complications had much higher concentrations of TF than others (P < .019). TF showed a strong positive correlation with the time of warm ischemia (r = 0.53864, P < .05)., Conclusions: The donor kidney appeared to be one of the main sources of TF in the blood of recipients. Warm ischemia significantly increased its concentration in renal vein blood. This concentration of TF may be associated with damage to the kidney. TF significantly increased the risk of postoperative complications., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Objectives: To evaluate the learning curve of robotic-assisted partial nephrectomy as it pertains to operative time (OT) and advanced perioperative variables such as achievement of trifecta, postoperative complications, 30-day readmission rates (RR), warm ischemia time (WIT), and functional volume loss (FVL)., Methods: We evaluated 418 consecutive robotic-assisted partial nephrectomy performed by a single surgeon between February 2008 and April 2019. Multivariable log-log regression models were used to evaluate the associations between case number and continuous outcomes (OT, WIT, and FVL). Multivariable logistic regression models were used to evaluate the association of case number with dichotomous outcomes (trifecta, postoperative complications, RR)., Results: Among the 406 eligible patients included in the study, 252 (62.1%) were male, median age was 63 years (range, 22-84), and median body mass index was 29 kg/m 2 (interquartile range 26-33). Surgeon experience was associated with shorter OT (-2.5% per 50% increase in case number; 95% confidence interval; P <.001) and plateaus around 77 cases performed. There was slight improvement with trifecta (odds ratio [per 50% increase in cases] = 1.08; 95% confidence interval) and the plateau was also at 77 cases, however, this was not statistically significant (P = .086). We did not find statistically significant associations of surgeon experience with FVL (P = .77), postoperative complications (P = .74), WIT (P = .73), or 30-day RR (P = .33)., Conclusion: There does not appear to be a relationship between surgical experience and grade 3 or higher postoperative complications, 30-day RR, WIT, or FVL. Trifecta outcomes and maximum OT performance appear to be optimized at approximately 77 cases., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Objective: To analyze the volumetric changes of the ipsilateral and contralateral kidneys and their effect on functional outcome post partial nephrectomy using segmentation analysis., Patients and Methods: We have analyzed the data of 119 patients from a single surgeon series of partial nephrectomy patients. Median follow-up was 11.40 months. Patients with bilateral tumors, and solitary kidney were excluded from analysis. Volumetric measurements were performed using a semiautomated tissue segmentation tool. A simple linear regression model to assess the predictors for parenchymal volume loss (PVL). A multivariable linear regression model was used to evaluate the association between PVL and warm ischemia time (WIT), controlling for other factors., Results: Mean WIT was 12.09 ± 4.40 minutes and the mean percentage decrease in the volume of the operated kidney was 16.99 ± 13.49%. WIT (β = 1.24, P < 0.001) and tumor complexity (simple vs. intermediate, β = 0.06, P = 0.984; simple vs. high, β = 11.62,P = 0.007) were associated with PVL. A 1 minute increase in WIT was associated with an increase in the percentage volume loss in the operated kidney by 1.38% (β = 1.20, P < 0.001). Patients with high tumor complexity (β = 11.17, P = 0.009) had a significantly higher percentage volume loss compared to patients with simple tumor complexity. Ipsilateral PVL (β = -0.35, P = 0.015) and male gender (β = -9.89, P = 0.021) were associated with change in eGFR. After adjusting for confounders, % volume loss (β = -0.32, P < 0.001) remained a significant predictor for contralateral hypertrophy., Conclusion: Tumor complexity results in higher WIT and increased PVL as measured by volumetric segmentation. PVL is a key factor associated with functional outcome, and is directly linked to WIT. Increased PVL is also associated with decreased contralateral hypertrophy. Prospective studies with larger samples sizes will be required to validate our findings., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Purpose: The influence of allograft ischemic time (IT) on short- and long-term mortality remains under debate in lung transplantation (LTx). Due to a scarcity in donors, better understanding of IT might improve the outcome after LTx. Methods: Between January 1990 and June 2016; 307 patients underwent LTx at Lund university hospital, Sweden. The end-point used was death/Re-LTx assessed by Cox regression and Kaplan-Meier survival. Results: Kaplan-Meier survival for mean IT (min) between subgroups ≤120, 121-240, 241-360 and 361+ showed significant difference for pairwise-comparisons with superior outcome for IT between ≤120 and 240 min. Cox regression analyses for each hour of IT in patients with a limited survival up to 1- and 5-year had a hazard ratio (HR) of 1.119 and 1.063 respectively ( p  < .05). Conclusions: In LTx, every 2-hour increase of IT is equivalent to an increased mortality of up to 24% within 5 years. LTx with an IT of ≤120 min had a superior survival in both 1- and 5 years in comparison to an IT of up to 360 min. Better application of IT provides a key role in improving LTx outcome.

Liver allograft rejection remains a significant cause of morbidity and graft failure in liver transplant recipients. Rejection is caused by the recognition of non-self donor alloantigens by recipient T-cells. Antigen recognition results in proliferation and activation of T-cells in lymphoid tissue before migration to the allograft. Activated T-cells have a variety of effector mechanisms including direct T-cell mediated damage to bile ducts, endothelium and hepatocytes and indirect effects through cytokine production and recruitment of tissue-destructive inflammatory cells. These effects explain the histological appearances of typical acute T-cell mediated rejection. In addition, donor specific antibodies, most typically against HLA antigens, may give rise to antibody-mediated rejection causing damage to the allograft primarily through endothelial injury. However, as an immune-privileged site there are several mechanisms in the liver capable of overcoming rejection and promoting tolerance to the graft, particularly in the context of recruitment of regulatory T-cells and promotors of an immunosuppressive environment. Indeed, around 20% of transplant recipients can be successfully weaned from immunosuppression. Hence, the host immunological response to the liver allograft is best regarded as a balance between rejection-promoting and tolerance-promoting factors. Understanding this balance provides insight into potential mechanisms for novel anti-rejection therapies., (Copyright © 2020 Ronca, Wootton, Milani and Cain.)

Prolonged warm (WIT) and cold (CIT) ischemia times are often important considerations in the discard of DCD kidneys, but their impact on post-transplant outcomes in the post-KAS era is unclear. We examined the association of ischemia time on delayed graft function (DGF) and death-censored graft failure for DCD kidneys. The 2018 SRTR SAF was utilized to identify post-KAS DCD kidney transplants occurring from 2015 to 2018. Relative risk and Cox regression were used to calculate risk of delayed graft function and hazard of death-censored graft failure, respectively. We identified 4,680 kidneys from DCD donors transplanted from 2015 to 2018 with recorded WIT and CIT times. Median WIT was 21.0 minutes (IQR 14.0-28.0), and CIT was 18.5 hours (IQR 13.9-23.5). The overall incidence of DGF was 42.7%. In a univariable relative risk regression model, extended CIT (24-30 hours:RR 1.37, 95% CI 1.15-1.77; >30 hours:RR 1.47, 95% CI 1.22-1.77) and WIT (20-40 minutes:RR 1.10, 95% CI 1.03-1.17) were associated with increased risk of DGF. When included in a multivariable model, neither prolonged CIT nor WIT were significantly associated with death-censored graft failure. Prolonged WIT and CIT are associated with increased DGF but not death-censored graft failure in recipients of DCD kidney transplants in the post-KAS era. Extended ischemia alone should not be used as a basis for discard or non-utilization of these organs., (© 2020 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)