Sodium thiosulfate-supplemented UW solution protects renal grafts against prolonged cold ischemia-reperfusion injury in a murine model of syngeneic kidney transplantation.

INTRODUCTION: Cold ischemia-reperfusion injury (IRI) is an inevitable event that increases post-transplant complications. We have previously demonstrated that supplementation of University of Wisconsin (UW) solution with non-FDA-approved hydrogen sulfide (H2S) donor molecules minimizes cold IRI and improves renal graft function after transplantation. The present study investigates whether an FDA-approved H2S donor molecule, sodium thiosulfate (STS), will have the same or superior effect in a clinically relevant rat model of syngeneic orthotopic kidney transplantation. METHOD: Thirty Lewis rats underwent bilateral nephrectomy followed by syngeneic orthotopic transplantation of the left kidney after 24-hour preservation in either UW or UW+STS solution at 4 °C. Rats were monitored to post-transplant day 14 and sacrificed to assess renal function (urine output, serum creatinine and blood urea nitrogen). Kidney sections were stained with H&E, TUNEL, CD68, and myeloperoxidase (MPO) to detect acute tubular necrosis (ATN), apoptosis, macrophage infiltration, and neutrophil infiltration. RESULT: UW+STS grafts showed significantly improved graft function immediately after transplantation, with improved recipient survival compared to UW grafts (p < 0.05). Histopathological examination revealed significantly reduced ATN, apoptosis, macrophage and neutrophil infiltration and downregulation of pro-inflammatory and pro-apoptotic genes in UW+STS grafts compared to UW grafts (p < 0.05). CONCLUSION: We show for the first time that preservation of renal grafts in STS-supplemented UW solution protects against prolonged cold IRI by suppressing apoptotic and inflammatory pathways, and thereby improving graft function and prolonging recipient survival. This could represent a novel clinically applicable therapeutic strategy to minimize the detrimental clinical outcome of prolonged cold IRI in kidney transplantation.

Differential inflammatory responses of the native left and right ventricle associated with donor heart preservation.

BACKGROUND: Dysfunction and inflammation of hearts subjected to cold ischemic preservation may differ between left and right ventricles, suggesting distinct strategies for amelioration. METHODS AND RESULTS: Explanted murine hearts subjected to cold ischemia for 0, 4, or 8 h in preservation solution were assessed for function during 60 min of warm perfusion and then analyzed for cell death and inflammation by immunohistochemistry and western blotting and total RNA sequencing. Increased cold ischemic times led to greater left ventricle (LV) dysfunction compared to right ventricle (RV). The LV experienced greater cell death assessed by TUNEL+ cells and cleaved caspase-3 expression (n = 4). While IL-6 protein levels were upregulated in both LV and RV, IL-1ß, TNFα, IL-10, and MyD88 were disproportionately increased in the LV. Inflammasome components (NOD-, LRR-, and pyrin domain-containing protein 3 (NLRP3), adaptor molecule apoptosis-associated speck-like protein containing a CARD (ASC), cleaved caspase-1) and products (cleaved IL-1ß and gasdermin D) were also more upregulated in the LV. Pathway analysis of RNA sequencing showed increased signaling related to tumor necrosis factor, interferon, and innate immunity with ex-vivo ischemia, but no significant differences were found between the LV and RV. Human donor hearts showed comparable inflammatory responses to cold ischemia with greater LV increases of TNFα, IL-10, and inflammasomes (n = 3). CONCLUSIONS: Mouse hearts subjected to cold ischemia showed time-dependent contractile dysfunction and increased cell death, inflammatory cytokine expression and inflammasome expression that are greater in the LV than RV. However, IL-6 protein elevations and altered transcriptional profiles were similar in both ventricles. Similar changes are observed in human hearts.

Subnormothermic Perfusion with H2S Donor AP39 Improves DCD Porcine Renal Graft Outcomes in an Ex Vivo Model of Kidney Preservation and Reperfusion.

Cold preservation is the standard of care for renal grafts. However, research on alternatives like perfusion at higher temperatures and supplementing preservation solutions with hydrogen sulfide (H2S) has gained momentum. In this study, we investigated whether adding H2S donor AP39 to porcine blood during subnormothermic perfusion at 21 °C improves renal graft outcomes. Porcine kidneys were nephrectomized after 30 min of clamping the renal pedicles and treated to 4 h of static cold storage (SCS) on ice or ex vivo subnormothermic perfusion at 21 °C with autologous blood alone (SNT) or with AP39 (SNTAP). All kidneys were reperfused ex vivo with autologous blood at 37 °C for 4 h. Urine output, histopathology and RNAseq were used to evaluate the renal graft function, injury and gene expression profiles, respectively. The SNTAP group exhibited significantly higher urine output than other groups during preservation and reperfusion, along with significantly lower apoptotic injury compared to the SCS group. The SNTAP group also exhibited differential pro-survival gene expression patterns compared to the SCS (downregulation of pro-apoptotic genes) and SNT (downregulation of hypoxia response genes) groups. Subnormothermic perfusion at 21 °C with H2S-supplemented blood improves renal graft outcomes. Further research is needed to facilitate the clinical translation of this approach.

A Novel Method to Improve Perfusion of Ex Vivo Pumped Human Kidneys.

OBJECTIVE: To determine if addition of the S-nitrosylating agent ethyl nitrite (ENO) to the preservation solution can improve perfusion parameters in pumped human kidneys. BACKGROUND: A significant percentage of actively stored kidneys experience elevations in resistance and decreases in flow rate during the ex vivo storage period. Preclinical work indicates that renal status after brain death is negatively impacted by inflammation and reduced perfusion-processes regulated by protein S-nitrosylation. To translate these findings, we added ENO to the preservation solution in an attempt to reverse the perfusion deficits observed in nontransplanted pumped human kidneys. METHODS: After obtaining positive proof-of-concept results with swine kidneys, we studied donated human kidneys undergoing hypothermic pulsatile perfusion deemed unsuitable for transplantation. Control kidneys continued to be pumped a 4°C (ie, standard of care). In the experimental group, the preservation solution was aerated with 50 ppm ENO in nitrogen. Flow rate and perfusion were recorded for 10 hours followed by biochemical analysis of the kidney tissue. RESULTS: In controls, perfusion was constant during the monitoring period (ie, flow rate remained low and resistance stayed high). In contrast, the addition of ENO produced significant and sustained reductions in resistance and increases in flow rate. ENO-treated kidneys had higher levels of cyclic guanosine monophosphate, potentially explaining the perfusion benefits, and increased levels of interleukin-10, suggestive of an anti-inflammatory effect. CONCLUSIONS: S-Nitrosylation therapy restored the microcirculation and thus improved overall organ perfusion. Inclusion of ENO in the renal preservation solution holds promise to increase the number and quality of kidneys available for transplant.

A novel histidine-tryptophan-ketoglutarate formulation ameliorates intestinal injury in a cold storage and ex vivo warm oxygenated reperfusion model in rats.

AIM: The present study aims to evaluate protective effects of a novel histidine-tryptophan-ketoglutarate solution (HTK-N) and to investigate positive impacts of an additional luminal preservation route in cold storage-induced injury on rat small bowels. METHODS: Male Lewis rats were utilized as donors of small bowel grafts. Vascular or vascular plus luminal preservation were conducted with HTK or HTK-N and grafts were stored at 4°C for 8 h followed by ex vivo warm oxygenated reperfusion with Krebs-Henseleit buffer for 30 min. Afterwards, intestinal tissue and portal vein effluent samples were collected for evaluation of morphological alterations, mucosal permeability and graft vitality. RESULTS: The novel HTK-N decreased ultrastructural alterations but otherwise presented limited effect on protecting small bowel from ischemia-reperfusion injury in vascular route. However, the additional luminal preservation led to positive impacts on the integrity of intestinal mucosa and vitality of goblet cells. In addition, vascular plus luminal preservation route with HTK significantly protected the intestinal tissue from edema. CONCLUSION: HTK-N protected the intestinal mucosal structure and graft vitality as a luminal preservation solution. Additional luminal preservation route in cold storage was shown to be promising.

Do storage solutions protect endothelial function of arterialized vein graft in an experimental rat model?

BACKGROUND: This study aims to compare the effects of storage solutions commonly used in coronary artery bypass grafting on the vascular reactivity in vein graft interposed in arterial position in syngeneic rats. METHODS: Twenty-seven male Lewis rats were sacrified to sample a vein graft implanted 6 weeks ago into abdominal aorta position. The vein grafts were inferior venae cavae initially pretreated with heparinized saline solution (HS) or autologous heparinized blood (AHB) or our referent solution, GALA. The endothelial functionality, the in situ Reactive Oxygen Species (ROS) levels and the histological characteristics were conducted from segments of arterialized vein graft. RESULTS: At 6 weeks, graft thrombosis occurred respectively in 22% of AHB group, 62.5% in the HS group and 82.5% in the GALA group. In each group, significative intimal hyperplasia was observed. After 6 weeks, an endothelium-remodeling layer associated with an increase of wall thickness was observed in each group. Endothelium-dependent tone was reduced in the vein graft regardless of the group. No difference was observed concerning the ROS in vein graft between the different groups. In distal aortic sections, ROS levels were increased in HS and GALA groups. CONCLUSIONS: Storage solutions used in this experimental model of vein graft implanted in arterial position cause graft injury and a complete disappearance of vascular reactivity. GALA solution did not reduce intimal risk hyperplasia when the vein graft was exposed to arterial flow in a rat model.

The Impact of Age and Luminal Preservation on the Development of Intestinal Preservation Injury in Rats.

BACKGROUND: Organs from older donors are believed to withstand ischemia worse than those from younger donors. The effect of age on the development of intestinal preservation injury (IPI) is unclear. METHODS: We compared the development of IPI in intestines from young (3 mo), adult (14 mo), and old (20 mo) rat donors and assessed if luminal preservation (LP) is effective in delaying IPI. Small intestines were perfused with, and stored in, preservation solution (Custodiol) with or without LP solution (polyethylene glycol 3350). IPI was studied using histology (Chiu score, Alcian blue staining), Western blot, and electrophysiological assessment (Ussing chamber) at 4, 8, and 14 hours. RESULTS: Intestines of old rats did not show major histological alterations, whereas their aortas and kidneys revealed typical age-related changes (arteriosclerosis and glomerulosclerosis). Intestines from old rats fared similarly to their younger counterparts at all time points regarding preservation injury and goblet cells count. Intestines undergoing LP showed fewer histological signs of damage and higher goblet cells count when compared with samples without LP, regardless of donor age. Ussing chamber experiments indicated a time-dependent deterioration of all parameters studied, which was delayed by the use of LP. CONCLUSIONS: Older intestines did not convincingly demonstrate a faster IPI compared with intestines from adult and young donors. The small differences between the age groups were nullified by the use of LP. LP significantly delayed the IPI in all age groups and may allow for longer preservation periods without an increased risk of mucosal damage.

Renal Protection Against Ischemia Reperfusion Injury: Hemoglobin-based Oxygen Carrier-201 Versus Blood as an Oxygen Carrier in Ex Vivo Subnormothermic Machine Perfusion.

BACKGROUND: The optimal method of oxygen delivery to donor kidneys during ex vivo machine perfusion has not been established. We have recently reported the beneficial effects of subnormothermic (22°C) blood perfusion in the preservation of porcine donation after circulatory death kidneys. Since using blood as a clinical perfusate has limitations, including matching availability and potential presence of pathogen, we sought to assess hemoglobin-based oxygen carrier (HBOC-201) in oxygen delivery to the kidney for renal protection. METHODS: Pig kidneys (n = 5) were procured after 30 minutes of warm in situ ischemia by cross-clamping the renal arteries. Organs were flushed with histidine tryptophan ketoglutarate solution and subjected to static cold storage or pulsatile perfusion with an RM3 pump at 22°C for 4 hours with HBOC-201 and blood. Thereafter, kidneys were reperfused with normothermic (37°C) oxygenated blood for 4 hours. Blood and urine were subjected to biochemical analysis. Total urine output, urinary protein, albumin/creatinine ratio, flow rate, resistance were measured. Acute tubular necrosis, apoptosis, urinary kidney damage markers, neutrophil gelatinase-associated lipocalin 1, and interleukin 6 were also assessed. RESULTS: HBOC-201 achieved tissues oxygen saturation equivalent to blood. Furthermore, upon reperfusion, HBOC-201 treated kidneys had similar renal blood flow and function compared with blood-treated kidneys. Histologically, HBOC-201 and blood-perfused kidneys had vastly reduced acute tubular necrosis scores and degrees of terminal deoxynucleotidyl transferase 2'-deoxyuridine, 5'-triphosphate nick end labeling staining versus kidneys treated with cold storage. Urinary damage markers and IL6 levels were similarly reduced by both blood and HBOC-201. CONCLUSIONS: HBOC-201 is an excellent alternative to blood as an oxygen-carrying molecule in an ex vivo subnormothermic machine perfusion platform in kidneys.

Supplementing preservation solution with mitochondria-targeted H2 S donor AP39 protects cardiac grafts from prolonged cold ischemia-reperfusion injury in heart transplantation.

Heart transplant has been accepted as the standard treatment for end-stage heart failure. Because of its susceptibility to ischemia-reperfusion injury, the heart can be preserved for only 4 to 6 hours in cold static preservation solutions. Prolonged ischemia time is adversely associated with primary graft function and long-term survival. New strategies to preserve donor hearts are urgently needed. We demonstrate that AP39, a mitochondria-targeting hydrogen sulfide donor, significantly increases cardiomyocyte viability and reduces cell apoptosis/death after cold hypoxia/reoxygenation in vitro. It also decreases gene expression of proinflammatory cytokines and preserves mitochondria function. Using an in vivo murine heart transplant model, we show that preserving donor hearts with AP39-supplemented University of Wisconsin solution (n = 7) significantly protects heart graft function, measured by quantitative ultrasound scan, against prolonged cold ischemia-reperfusion injury (24 hours at 4°C), along with reducing tissue injury and fibrosis. Our study demonstrates that supplementing preservation solution with AP39 protects cardiac grafts from prolonged ischemia, highlighting its therapeutic potential in preventing ischemia-reperfusion injury in heart transplant.

Long-term Effects of Hypothermic Ex Situ Perfusion on Skeletal Muscle Metabolism, Structure, and Force Generation After Transplantation.

BACKGROUND: Hypothermic ex situ perfusion (HESP) systems are used to prolong allograft survival in solid organ transplantations and have been shown to be superior to static cold storage (SCS) methods. However, the effect of this preservation method on limb allograft survival and long-term function has not yet been tested. In this study, we investigated the long-term effects of the HESP on skeletal muscle metabolism, structure, and force generation and compared it with the current standard of preservation. METHODS: Forty male Lewis rats (250 ± 25 g) were divided into 5 groups, including naive control, sciatic nerve transection or repair, immediate transplantation, SCS, and HESP. For the SCS group, limbs were preserved at 4°C for 6 hours. In the HESP group, limbs were continuously perfused with oxygenated histidine-tryptophan-ketoglutarate (HTK) solution at 10-15°C for 6 hours. Hemodynamic and biochemical parameters of perfusion were recorded throughout the experiment. At 12 weeks, electromyography and muscle force measurements (maximum twitch and tetanic forces) were obtained along with muscle samples for histology and metabolomics analysis. RESULTS: Histology demonstrated 48% myocyte injury in the HESP group compared with 49% in immediate transplantation (P = 0.96) and 74% in the SCS groups (P < 0.05). The maximum twitch force measurement revealed a significantly higher force in the HESP group compared with the SCS group (P = 0.029). Essential amino acid levels of the gastrocnemius muscle did not reach significance, with the exception of higher proline levels in the HESP group. CONCLUSIONS: HESP using HTK protects viability of the limb but fails to restore muscle force in the long term.

The Novel N,N-bis-2-Hydroxyethyl-2-Aminoethanesulfonic Acid-Gluconate-Polyethylene Glycol-Hypothermic Machine Perfusion Solution Improves Static Cold Storage and Reduces Ischemia/Reperfusion Injury in Rat Liver Transplant.

Organ transplantation is the treatment of choice against terminal and irreversible organ failure. Optimal preservation of the graft is crucial to counteract cold ischemia effects. As we developed an N,N-bis-2-hydroxyethyl-2-aminoethanesulfonic acid-gluconate-polyethylene glycol (BGP)-based solution (hypothermic machine perfusion [HMP]), we aimed to analyze the use of this solution on static cold storage (SCS) of rat livers for transplantation as compared with the histidine tryptophan ketoglutarate (HTK) preservation solution. Livers procured from adult male Sprague Dawley rats were preserved with BGP-HMP or HTK solutions. Liver total water content and metabolites were measured during the SCS at 0°C for 24 hours. The function and viability of the preserved rat livers were first assessed ex vivo after rewarming (90 minutes at 37°C) and in vivo using the experimental model of reduced-size heterotopic liver transplantation. After SCS, the water and glycogen content in both groups remained unchanged as well as the tissue glutathione concentration. In the ex vivo studies, livers preserved with the BGP-HMP solution were hemodynamically more efficient and the O2 consumption rate was higher than in livers from the HTK group. Bile production and glycogen content after 90 minutes of normothermic reperfusion was diminished in both groups compared with the control group. Cellular integrity of the BGP-HMP group was better, and the histological damage was reversible. In the in vivo model, HTK-preserved livers showed a greater degree of histological injury and higher apoptosis compared with the BGP-HMP group. In conclusion, our results suggest a better role of the BGP-HMP solution compared with HTK in preventing ischemia/reperfusion injury in the rat liver model.

Effects of Oxygen During Long-term Hypothermic Machine Perfusion in a Porcine Model of Kidney Donation After Circulatory Death.

BACKGROUND: Hypothermic machine perfusion (HMP) has become standard care in many center's to preserve kidneys donated after circulatory death (DCD). Despite a significant reduction in metabolism at low temperatures, the remaining cellular activity requires oxygen. Because of the role and safety of oxygen during HMP has not been fully clarified, its supply during HMP is not standard yet. This study investigates the effect of administering oxygen during HMP on renal function in a porcine DCD model. METHODS: After 30 minutes of warm ischemia, porcine slaughterhouse kidneys were preserved for 24 hours by means of cold storage (CS), or HMP with Belzer Machine Perfusion Solution supplemented with no oxygen, 21% or 100% oxygen. Next, kidneys were reperfused for 4 hours in a normothermic machine perfusion setup. RESULTS: HMP resulted in significantly better kidney function during normothermic machine perfusion. Thiobarbituric acid-reactive substances, markers of oxidative stress, were significantly lower in HMP preserved kidneys. HMP preserved kidneys showed significantly lower aspartate aminotransferase and lactate dehydrogenase levels compared with kidneys preserved by CS. No differences were found between the HMP groups subjected to different oxygen concentrations. Adenosine triphosphate levels significantly improved during HMP when active oxygenation was applied. CONCLUSIONS: This study showed that preservation of DCD kidneys with HMP is superior to CS. Although the addition of oxygen to HMP did not result in significantly improved renal function, beneficial effects were found in terms of reduced oxidative stress and energy status. Oxygen addition proofed to be safe and did not show detrimental effects.

Hypothermic perfusion of donor heart with a preservation solution supplemented by mesenchymal stem cells.

BACKGROUND: Heart transplantation is the definitive treatment for end-stage heart failure. A shortage of donor hearts forced transplant programs to accept older donors and longer ischemic times. Previous studies have suggested that administration of mesenchymal stem cells (MSCs) or their conditioned medium (CM) protects the heart against ischemia/reperfusion injury (IRI). We hypothesized that the preservation of donor hearts with a CM would protect the graft from IRI after prolonged storage in 15-month-old rats and investigated mRNA changes attributable to CM. METHODS: Rat MSCs were isolated and cultured. The CM was used and characterized by a 90-antibody array, revealing the presence of 28 factors involved in apoptosis, inflammation, and oxidative stress. Hearts from 15-month-old donor rats were explanted and continuously perfused for 5 hours with oxygenated, 4°C cardioplegic solution, and supplemented with either regular cell culture medium (control group) or CM. The hearts were then heterotopically transplanted. We evaluated in-vivo left ventricular graft function 1.5 hours after transplantation and the myocardial expression of 120 genes using polymerase chain reaction arrays. RESULTS: Systolic contractility and relaxation parameters were significantly reduced in 15-month-old rats compared with the young rats. After transplantation, systolic function (dP/dtmax: 1,197 ± 94 vs 1,825 ± 279 mm Hg/s at 140 µl; p < 0.05) and diastolic function (dP/dtmin: 737 ± 168 vs 1,200 ± 166 mm Hg/s at 140 µl, p < 0.05) were significantly improved in the CM group compared with controls. Among the genes surveyed, the expressions of 66 were altered. Genes of pro-inflammatory cytokines and interleukins were down-regulated, whereas expression of the anti-oxidant gene superoxide dismutase-2 was up-regulated in the CM-treated grafts compared with the control group grafts. CONCLUSIONS: Perfusion of donor hearts with CM protects against myocardial IRI in 15-month-old rats.

Prediction of transplant outcome after 24-hour ex vivo lung perfusion using the Organ Care System in a porcine lung transplantation model.

Ex vivo lung perfusion (EVLP) has become routine practice in lung transplantation. Still, running periods exceeding 12 hours have not been undertaken clinically to date, and it remains unclear how the perfusion solution for extended running periods should be composed and which parameters may predict outcomes. Twenty-four porcine lungs underwent EVLP for 24 hours using the Organ Care System (OCS). Lungs were ventilated and perfused with STEEN's solution enriched with erythrocytes (n = 8), acellular STEEN's solution (n = 8), or low-potassium dextran (LPD) solution enriched with erythrocytes (n = 8). After 24 hours, the left lungs were transplanted into recipient pigs. After clamping of the contralateral lung, the recipients were observed for 6 hours. The most favorable outcome was observed in organs utilizing STEEN solution enriched with erythrocytes as perfusate, whereas the least favorable outcome was seen with LPD solution enriched with erythrocytes for perfusion. Animals surviving the observation period showed lower peak airway pressure (PAWP) and pulmonary vascular resistance (PVR) during OCS preservation. The results suggest that transplantation of lungs following 24 hours of EVLP is feasible but dependent on the composition of the perfusate. PAWP and PVR during EVLP are early and late predictors of transplant outcome, respectively.

Optimum Perfusate Volume of Purified Subnormothermic Machine Perfusion for Porcine Liver Donated After Cardiac Death.

INTRODUCTION: Subnormothermic machine perfusion (SNMP) shows some advantages for the preservation of grafts donated after cardiac death (DCD) and improvements in machine perfusion (MP) technology are important to enhance organ preservation outcomes for liver transplantation. In this study, we focused on purified subnormothermic machine perfusion (PSNMP) and volumes of perfusate removed to substitute for purification and replaced by modified University of Wisconsin-gluconate after the start of perfusion and investigated, in particular, the optimum perfusate purification volume. Several purification volumes under SNMP were compared. In addition, the perfusate purification during MP was indicated as a potential technique to enhance the organ quality of DCD grafts and extended-criteria donors. METHODS: The PSNMP at several volumes (0.5 L, 1.5 L, and 3 L) were compared with regular SNMP without any purification treatment (untreated control). In the PSNMP group, all perfusate was removed to substitute for purification of the perfusate by modified University of Wisconsin-gluconate solution after the start of perfusion. After removing the perfusate, new perfusate with the same components was perfused to preserve the porcine livers obtained under warm ischemia for 60 minutes using SNMP at 22°C porcine liver for 4 hours. RESULTS: The concentrations of aspartate aminotransferase and lactate dehydrogenase in the untreated group were significantly higher during perfusion compared to those of the intervention group. There are no significant differences among the volume conditions of the purification groups. CONCLUSIONS: The optimal volume of perfusate purification was confirmed with a simple experimental comparison between untreated and PSNMP conditions.

Combined Flush With Histidine-Tryptophan-Ketoglutarate and University of Wisconsin Solutions in Liver Transplantation: Preliminary Results.

INTRODUCTION: Ischemia reperfusion injury (IRI) is the main cause of early allograft dysfunction (EAD) and subsequent primary allograft failure (PAF). OBJECTIVES: The purpose of this study is to compare IRI, EAD, and PAF in liver transplantation in a cohort of patients perfused with histidine-tryptophan-ketoglutarate (HTK) solution and University of Wisconsin (UW) solution versus HTK alone. METHODS: A randomized trial was performed to compare outcomes in liver recipients who underwent transplantation surgery in the University Regional Hospital of Malaga, Spain. Forty patients were randomized to two groups. Primary endpoints included IRI, EAD, PAF, re-intervention, acute cellular rejection, retransplantation, arterial complications, and biliary complications at postoperative day 90. RESULTS: Postoperative glutamic oxaloacetic transaminase (1869.15 ± 1559.75 UI/L vs. 953.15 ± 777.27 UI/L; P = .004) and glutamic pyruvic transaminase (1333.60 ± 1115.49 U/L vs. 721.70 ± 725.02 U/L; P = .023) were significantly higher in patients perfused with HTK alone. A clear tendency was observed in recipients perfused with HTK alone to present moderate to severe IRI (7 patients in the HTK + UW solution group vs. 15 patients in the HTK-alone solution group; P = .06), EAD (0 patients in the HTK + UW solution group vs. 0 patients in the HTK-alone solution group; P = .76), and PAF (3 patients in the HTK + UW solution group vs. 8 patients in the HTK-alone solution group; P = .15). CONCLUSIONS: Initial perfusion with HTK solution followed by UW solution in liver transplantation improves early liver function as compared to perfusion with HTK alone.

Retrograde Flushing of Living Donor Renal Allografts via the Renal Vein: A Simple, Effective Technique.

BACKGROUND: Prograde flushing (PF) of living donor renal allografts with preservation solution via the renal artery or arteries is standard practice. PF may be difficult and potentially injurious to the donor kidney, especially in grafts with small or multiple arteries. In this report, we present our experience with retrograde flushing (RF) of 7 living donor kidneys via the renal vein. METHODS: Retrospective review of 7 consecutive living donor renal transplants performed using the RF technique was performed. The 7 preceding living donor renal transplants performed using the standard arterial PF technique served as a control group. RESULTS: All 7 recipients of RF kidneys experienced immediate graft function. At postoperative days 3 and 30, there was no difference in estimated glomerular filtration rate between the RF study group and PF controls. CONCLUSIONS: The RF technique is simple and safe, with results equivalent to the PF technique. The RF technique may be especially useful after recovering kidneys with small and/or multiple arteries.

N-acetylcysteine improves the quality of red blood cells stored for transfusion.

Storage inflicts a series of changes on red blood cells (RBC) that compromise the cell survival and functionality; largely these alterations (storage lesions) are due to oxidative modifications. The possibility of improving the quality of packed RBC stored for transfusion including N-acetylcysteine (NAC) in the preservation solution was explored. Relatively high concentrations of NAC (20-25 mM) were necessary to prevent the progressive leakage of hemoglobin, while lower concentrations (≥2.5 mM) were enough to prevent the loss of reduced glutathione during the first 21 days of storage. Peroxiredoxin-2 was also affected during storage, with a progressive accumulation of disulfide-linked dimers and hetero-protein complexes in the cytosol and also in the membrane of stored RBC. Although the presence of NAC in the storage solution was unable to avoid the formation of thiol-mediated protein complexes, it partially restored the capacity of the cell to metabolize H2O2, indicating the potential use of NAC as an additive in the preservation solution to improve RBC performance after transfusion.

Effects of N-Acetylcysteine Addition to University of Wisconsin Solution on the Rate of Ischemia-Reperfusion Injury in Adult Orthotopic Liver Transplant.

OBJECTIVES: One of the main concerns in liver transplant is the prolonged ischemia time, which may lead to primary graft nonfunction or delayed function. N-acetylcysteine is known as a hepato-protective agent in different studies, which may improve human hepatocyte viability in steatotic donor livers. This study investigated whether N-acetylcysteine can decrease the rate of ischemia-reperfusion syndrome and improve short-term outcome in liver transplant recipients. MATERIALS AND METHODS: This was a double-blind, randomized, control clinical trial of 115 patients. Between April 2012 and January 2013, patients with orthotopic liver transplant were randomly divided into 2 groups; in 49 cases N-acetylcysteine was added to University of Wisconsin solution as the preservative liquid (experimental group), and in 66 cases standard University of Wisconsin solution was used (control group). We compared postreperfusion hypotension, inotrope requirement before and after portal reperfusion, intermittent arterial blood gas analysis and potassium measurement, pathological review of transplanted liver, in-hospital complications, morbidity, and mortality. RESULTS: There was no significant difference between the groups regarding time to hepatic artery reperfusion, hospital stay, vascular complications, inotrope requirement before and after portal declamping, and blood gas analysis. Hypotension after portal reperfusion was significantly more common in experimental group compared with control group (P = .005). Retransplant and in-hospital mortality were comparable between the groups. CONCLUSIONS: Preservation of the liver inside Univer-sity of Wisconsin solution plus N-acetylcysteine did not change the rate of ischemia reperfusion injury and short-term outcome in liver transplant recipients.

[Toward a customized preservation for each kidney graft?] / Vers une personnalisation de la conservation des greffons rénaux ?

The increased number of patients in waiting list for renal transplantation requires the establishment of recommendations regarding graft preservation techniques. The preservation method impacts graft function and survival particularly in case of extended criteria donors. Based on our experience, the aim of this review is to establish a decisional diagram to draw graft management to 5years in relation to donor type and graft quality. Novel biomarkers are necessary to evaluate graft quality. Nuclear magnetic resonance or transcriptomic analyses are promising. Thus, good quality organs will be preserved in static condition associated to hypothermia; while grafts from extended criteria donors need to be assessed early during dynamic perfusion through an evaluation of perfusion solution to discriminate: good organs, with acceptable risks without perfusion conditions modifications; tolerable risk grafts for which it will be recommended to use a supplementation of perfusion solution with oxygen or pharmacologic additives such as mitochondrion protectors or oxygen carriers; and elevated risks graft which will not be used. This diagram based on experimental data needs to be assessed in clinical trials but highlights the crucial role of kidney graft quality assessment for its management and placed dynamic perfusion preservation as the protocol of choice for extended criteria donors.