Impact of Cold Ischemia on the Stability of 1H-MRS-Detected Metabolic Profiles of Ovarian Cancer Specimens

Proton magnetic resonance spectroscopy (1H-MRS) of surgically collected tumor specimens may contribute to investigating cancer metabolism and the significance of the "total choline" (tCho) peak (3.2 ppm) as malignancy and therapy response biomarker. To ensure preservation of intrinsic metabolomic information, standardized handling procedures are needed. The effects of time to freeze (cold ischemia) were evaluated in (a) surgical epithelial ovarian cancer (EOC) specimens using high-resolution (HR) 1H-MRS (9.4 T) of aqueous extracts and (b) preclinical EOC samples (xenografts in SCID mice) investigated by in vivo MRI-guided 1H-MRS (4.7 T) and by HR-1H-MRS (9.4 T) of tumor extracts or intact fragments (using magic-angle-spinning (MAS) technology). No significant changes were found in the levels of 27 of 29 MRS-detected metabolites (including the tCho profile) in clinical specimens up to 2 h cold ischemia, besides an increase in lysine and a decrease in glutathione. EOC xenografts showed a 2-fold increase in free choline within 2 h cold ischemia, without further significant changes for any MRS-detected metabolite (including phosphocholine and tCho) up to 6 h. At shorter times (≤1 h), HR-MAS analyses showed unaltered tCho components, along with significant changes in lactate, glutamate, and glutamine. Our results support the view that a time to freeze of 1 h represents a safe threshold to ensure the maintenance of a reliable tCho profile in EOC specimens.

Impact of Decalcification, Cold Ischemia, and Deglycosylation on Performance of Programmed Cell Death Ligand-1 Antibodies With Different Binding Epitopes: Comparison of 7 Clones

Programmed cell death ligand-1 (PD-L1) expression levels in patients' tumors have demonstrated clinical utility across many cancer types and are used to determine treatment eligibility. Several independently developed PD-L1 immunohistochemical (IHC) predictive assays are commercially available and have demonstrated different levels of staining between assays, generating interest in understanding the similarities and differences between assays. Previously, we identified epitopes in the internal and external domains of PD-L1, bound by antibodies in routine clinical use (SP263, SP142, 22C3, and 28-8). Variance in performance of assays utilizing these antibodies, observed following exposure to preanalytical factors such as decalcification, cold ischemia, and duration of fixation, encouraged additional investigation of antibody-binding sites, to understand whether binding site structures/conformations contribute to differential PD-L1 IHC assay staining. We proceeded to further investigate the epitopes on PD-L1 bound by these antibodies, alongside the major clones utilized in laboratory-developed tests (E1L3N, QR1, and 73-10). Characterization of QR1 and 73-10 clones demonstrated that both bind the PD-L1 C-terminal internal domain, similar to SP263/SP142. Our results also demonstrate that under suboptimal decalcification or fixation conditions, the performance of internal domain antibodies is less detrimentally affected than that of external domain antibodies 22C3/28-8. Furthermore, we show that the binding sites of external domain antibodies are susceptible to deglycosylation and conformational structural changes, which directly result in IHC staining reduction or loss. The binding sites of internal domain antibodies were unaffected by deglycosylation or conformational structural change. This study demonstrates that the location and conformation of binding sites, recognized by antibodies employed in PD-L1 diagnostic assays, differ significantly and exhibit differing degrees of robustness. These findings should reinforce the need for vigilance when performing clinical testing with different PD-L1 IHC assays, particularly in the control of cold ischemia and the selection of fixation and decalcification conditions.

Cellular Cytosolic Energy Replenishment Increases Vascularized Composite Tissue Tolerance to Extended Cold Ischemia Time

BACKGROUND

Vascularized composite allotransplantation (VCA) is a restorative surgical procedure to treat whole or partially disfiguring craniofacial or limb injuries. The routine clinical use of this VCA surgery is limited using compromised allografts from deceased donors and by the failure of the current hypothermic preservation protocols to extend the allograft's cold ischemia time beyond 4 h. We hypothesized that the active replenishment of the cellular cytosolic adenosine-5`-triphosphate (ATP) stores by means of energy delivery vehicles (ATPv) encapsulating high-energy ATP is a better strategy to improve allograft's tolerance to extended cold ischemia times.

MATERIALS AND METHODS

We utilized established rat model of isolated bilateral in-situ non-cycled perfusions of both hind limbs. Ipsilateral and contralateral limbs in the anesthetized animal were randomized for simultaneous perfusions with either the University of Wisconsin (UW) solution, with/without O2 supplementation (control), or with the UW solution supplemented with the ATPv, with/without O2 supplementation (experimental). Following perfusion, the hind limbs were surgically removed and stored at 4°C for 12, 16, or 24 hours as extended cold ischemia times. At the end of each respective storage time, samples of skin, and soleus, extensor digitalis longus, and tibialis anterior muscles were recovered for assessment using tissue histology and tissue lysate studies.

RESULTS

Control muscle sections showed remarkable microvascular and muscle damage associated with loss of myocyte transverse striation and marked decrease in myocyte nucleus density. A total of 1,496 nuclei were counted in 179 sections of UW-perfused control muscles in contrast to 1,783 counted in 130 sections of paired experimental muscles perfused with the ATPv-enhanced perfusate. This yielded 8 and 13 nuclei/field for the control and experimental muscles, respectively (P < .004). Oxygenation of the perfusion solutions before use did not improve the nucleus density of either the control or experimental muscles (n = 7 animals, P > .05). Total protein isolated from the muscle lysates was similar in magnitude regardless of muscle type, perfusion protocol, or duration of cold ischemia time. Prolonged static cold preservation of the hind limbs completely degraded the composite tissue's Ribonucleic acid (RNA). This supplementary result confirms the notion that that reverse transcription-Polymerase Chain Reaction, enzyme-linked immunosorbent assay, or the respiratory complex II enzyme activity techniques should not be used as indices of graft quality after prolonged static cold storage.

CONCLUSIONS

In conclusion, this study demonstrates that active cellular cytosolic ATP replenishment increases hind limb composite tissue tolerance to extended cold ischemia times. Quality indicators and clinically relevant biomarkers that define composite tissue viability and function during static cold storage are warranted.

Exceeding the Limits of Static Cold Storage in Limb Transplantation Using Subnormothermic Machine Perfusion

BACKGROUND

 For 50 years, static cold storage (SCS) has been the gold standard for solid organ preservation in transplantation. Although logistically convenient, this preservation method presents important constraints in terms of duration and cold ischemia-induced lesions. We aimed to develop a machine perfusion (MP) protocol for recovery of vascularized composite allografts (VCA) after static cold preservation and determine its effects in a rat limb transplantation model.

METHODS

 Partial hindlimbs were procured from Lewis rats and subjected to SCS in Histidine-Tryptophan-Ketoglutarate solution for 0, 12, 18, 24, and 48 hours. They were then either transplanted (Txp), subjected to subnormothermic machine perfusion (SNMP) for 3 hours with a modified Steen solution, or to SNMP + Txp. Perfusion parameters were assessed for blood gas and electrolytes measurement, and flow rate and arterial pressures were monitored continuously. Histology was assessed at the end of perfusion. For select SCS durations, graft survival and clinical outcomes after transplantation were compared between groups at 21 days.

RESULTS

 Transplantation of limbs preserved for 0, 12, 18, and 24-hour SCS resulted in similar survival rates at postoperative day 21. Grafts cold-stored for 48 hours presented delayed graft failure (p = 0.0032). SNMP of limbs after 12-hour SCS recovered the vascular resistance, potassium, and lactate levels to values similar to limbs that were not subjected to SCS. However, 18-hour SCS grafts developed significant edema during SNMP recovery. Transplantation of grafts that had undergone a mixed preservation method (12-hour SCS + SNMP + Txp) resulted in better clinical outcomes based on skin clinical scores at day 21 post-transplantation when compared to the SCS + Txp group (p = 0.01613).

CONCLUSION

 To date, VCA MP is still limited to animal models and no protocols are yet developed for graft recovery. Our study suggests that ex vivo SNMP could help increase the preservation duration and limit cold ischemia-induced injury in VCA transplantation.

Preliminary mechanism of inhibitor of SGLT2 in fatty liver cold ischemia injury

With rapid development of liver transplantation technology, the demand for transplants have reached beyond the supply of organs, and thus development of effective strategies to reduce cold ischemia injury in fatty liver is important. Here, we explored the potential effect of SGLT-2 inhibitor in cold ischemia injury, fatty livers from 2 weeks methionine and choline deficient diet (MCD) rats were administered. After one week of intragastric administration of Sodium-dependent glucose transporters (SGLT-2) inhibitor empagliflozin (EMPA) or NaCI, liver were stored for 24 h. The results showed that EMPA could significantly reduce the cold ischemic injury in the mitochondria of fatty liver. To explore the mechanism, signal transducers and activators of transcription 3(STAT3) inhibitor AG490 group was used in a similar manner. We detected the changes in p-signal transducers and activators of transcription 3 (P-STAT3), alcohol-dehydrogenase 2 (ALDH2) and degree of apoptosis in three distinct groups. The results suggested that the protein expression of P-STAT3 and ALDH2 was higher in the EMPA group than in other two groups, whereas extent of apoptosis in the EMPA group was lower than other two groups. The data suggested that SGLT2 inhibitors could alleviate cold ischemia damage of mitochondria in fatty liver, which may be related to the inhibition of apoptosis and the activation of P-STAT3 and ALDH2.

Extracellular Vesicles Released During Normothermic Machine Perfusion Are Associated With Human Donor Kidney Characteristics

BACKGROUND

Extracellular vesicles (EVs) are tissue-specific particles released by cells containing valuable diagnostic information in the form of various biomolecules. The characterization of EVs released by kidney grafts during normothermic machine perfusion (NMP) may present a promising avenue to assess graft status before transplantation.

METHODS

We phenotyped and determined the concentrations of EVs in the perfusate of 8 discarded expanded-criteria donor human kidneys during 6 h of NMP. Perfusate samples were taken at 0/60/180/360 min and examined with nanoparticle tracking analysis and imaging flow cytometry (IFCM). Using IFCM, EVs were identified by their expression of common EV markers CD9, CD63, and CD81 (tetraspanins) in combination with either platelet endothelial cell adhesion molecule (CD31), pan-leukocyte protein (CD45), or carboxyfluorescein succiminidyl ester (CFSE) fluorescence.

RESULTS

Nanoparticle tracking analysis measurements revealed the release of nanoparticles <400 nm into the perfusate during NMP. With IFCM, tetraspanin protein signatures of the released nanoparticles were characterized, and the majority (~75%) of CFSE+ EVs were found to be CD81+, whereas ~16% were CD9+ and ~8% CD63+. Correlation analysis of concentrations of identified EV subsets with crude donor characteristics and NMP viability characteristics revealed significant correlations with cold ischemia time, donor age, and renal flow.

CONCLUSIONS

Our findings demonstrate that discarded expanded-criteria donor kidney grafts release distinct EV subsets during NMP. Because these subsets correlate with well-established indicators of transplant outcome, EVs might represent new potential candidates for assessment of kidney graft quality.

Implications of Accumulated Cold Time for US Kidney Transplantation Offer Acceptance

BACKGROUND AND OBJECTIVES

Reducing discard is important for the US transplantation system because nearly 20% of the deceased donor kidneys are discarded. One cause for the discards is the avoidance of protracted cold ischemia times. Extended cold ischemia times at transplant are associated with additional risk of graft failure and patient mortality. A preference for local (within the same donor service area) or low-Kidney Donor Risk Index organs, the endogeneity of cold ischemia time during organ allocation, and the use of provisional offers all complicate the analysis of cold ischemia times' influence on kidney acceptance decision making.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Using January 2018 to June 2019 Organ Procurement and Transplantation Network data, we modeled the probability of accepting an offer for a kidney after provisional acceptance. We use logistic regression that includes cold ischemia time, Kidney Donor Risk Index, and other covariates selected from literature. Endogeneity of cold ischemia time was treated by a two-stage instrumental variables approach.

RESULTS

Logistic regression results for 3.33 million provisional acceptances from 12,369 donors and 108,313 candidates quantify trade-offs between cold ischemia time at the time of offer acceptance and donor-recipient characteristics. Overall, each additional 2 hours of cold ischemia time affected acceptance for nonlocal and local recipients (odds ratio, 0.75; 95% confidence interval, 0.73 to 0.77, odds ratio, 0.88; 95% confidence interval, 0.86 to 0.91; P<0.001). For Kidney Donor Risk Index >1.75 (Kidney Donor Profile Index >85) kidneys, an additional 2 hours of cold ischemia time for nonlocal and local recipients was associated with acceptance with odds ratio, 0.58; 95% confidence interval, 0.54 to 0.63 (nonlocal) and odds ratio, 0.65; 95% confidence interval, 0.6 to 0.7 (local); P<0.001. The effect of an additional 2 hours of cold ischemia time on acceptance of kidneys with Kidney Donor Risk Index ≤1.75 (Kidney Donor Profile Index ≤85) was less pronounced for nonlocal offers (odds ratio, 0.82; 95% confidence interval, 0.80 to 0.85; P<0.001) and not significant for local offers.

CONCLUSIONS

The acceptability of marginal organs was higher when placements were nearer to the donor and when cold ischemia time was shorter.

The Effects of Free Heme on Functional and Molecular Changes During Ex Vivo Normothermic Machine Perfusion of Human Kidneys

Normothermic machine perfusion (NMP) is a technique of kidney preservation designed to restore cellular metabolism after cold ischemia. Kidneys are perfused with an oxygenated banked red blood cell (RBC) based solution for 1h at 36°C. During NMP, RBCs can become damaged, releasing free heme into the perfusate. This can act as a damage-associated molecular pattern (DAMP) activating inflammatory signalling pathways. The aim of this study was to measure the levels of free heme during NMP, assess the effect on kidney function and determine any association with inflammatory and stress related gene expression. Levels of free heme were measured in perfusate samples from a series of donation after circulatory death (DCD) kidneys undergoing NMP as part of a randomised controlled trial (RCT). The age of RBCs and levels of free heme were correlated with perfusion parameters. Changes in gene expression were analysed in a series of kidneys declined for transplantation using the NanoString nCounter Organ Transplant Panel and qRT-PCR. Older units of RBCs were associated with higher levels of free heme and levels increased significantly during NMP (Pre 8.56 ± 7.19µM vs 26.29 ± 15.18µM, P<0.0001). There was no association with levels of free heme and perfusion parameters during NMP (P > 0.05). Transcriptional and qPCR analysis demonstrated the upregulation of differentially expressed genes associated with apoptosis (FOS and JUN), inflammatory cytokines (IL-6, SOCS3, ATF3), chemokines (CXCL8, CXCL2, CC3/L1) and oxidative stress (KLF4) after NMP. However, these did not correlate with levels of free heme (P >0.05). A significant amount of free heme can be detected in the perfusate before and after NMP particularly when older units of red cells are used. Although transcriptional analysis demonstrated significant upregulation of genes involved with apoptotic, inflammatory and oxidative pathways these were not associated with high levels of free heme.

Mesenchymal stem cell secretions improve donor heart function following ex vivo cold storage

OBJECTIVES

Heart transplantation is the gold standard of treatments for end-stage heart failure, but its use is limited by extreme shortage of donor organs. The time "window" between procurement and transplantation sets the stage for myocardial ischemia/reperfusion injury, which constrains the maximal storage time and lowers use of donor organs. Given mesenchymal stem cell (MSC)-derived paracrine protection, we aimed to evaluate the efficacy of MSC-conditioned medium (CM) and extracellular vesicles (EVs) when added to ex vivo preservation solution on ameliorating ischemia/reperfusion-induced myocardial damage in donor hearts.

METHODS

Mouse donor hearts were stored at 0°C-4°C of <1-hour cold ischemia (<1hr-I), 6hr-I + vehicle, 6hr-I + MSC-CM, 6hr-I + MSC-EVs, and 6hr-I + MSC-CM from MSCs treated with exosome release inhibitor. The hearts were then heterotopically implanted into recipient mice. At 24 hours postsurgery, myocardial function was evaluated. Heart tissue was collected for analysis of histology, apoptotic cell death, microRNA (miR)-199a-3p expression, and myocardial cytokine production.

RESULTS

Six-hour cold ischemia significantly impaired myocardial function, increased cell death, and reduced miR-199a-3p in implanted hearts versus <1hr-I. MSC-CM or MSC-EVs in preservation solution reversed the detrimental effects of prolong cold ischemia on donor hearts. Exosome-depleted MSC-CM partially abolished MSC secretome-mediated cardioprotection in implanted hearts. MiR-199a-3p was highly enriched in MSC-EVs. MSC-CM and MSC-EVs increased cold ischemia-downregulated miR-199a-3p in donor hearts, whereas exosome-depletion neutralized this effect.

CONCLUSIONS

MSC-CM and MSC-EVs confer improved myocardial preservation in donor hearts during prolonged cold static storage and MSC-EVs can be used for intercellular transport of miRNAs in heart transplantation.

Association of Transit Time With Cold Ischemic Time in Kidney Transplantation

This cross-sectional study examines the association between transit time and cold ischemic time for adult, deceased kidney transplant donors.

Beneficial effects of end-ischemic oxygenated machine perfusion preservation for split-liver transplantation in recovering graft function and reducing ischemia-reperfusion injury

This study examined the efficacy of end-ischemic hypothermic oxygenated machine perfusion preservation (HOPE) using an originally developed machine perfusion system for split-liver transplantation. Porcine split-liver grafts were created via 75% liver resection after 10 min of warm ischemia. In Group 1, grafts were preserved by simple cold storage (CS) for 8 h (CS group; n = 4). In Group 2, grafts were preserved by simple CS for 6 h and end-ischemic HOPE for 2 h (HOPE group; n = 5). All grafts were evaluated using an isolated ex vivo reperfusion model with autologous blood for 2 h. Biochemical markers (aspartate aminotransferase and lactate dehydrogenase levels) were significantly better immediately after reperfusion in the HOPE group than in the CS group. Furthermore, the HOPE group had a better histological score. The levels of inflammatory cytokines (tumor necrosis factor-α, interferon-γ, interleukin-1β, and interleukin-10) were significantly lower after reperfusion in the HOPE group. Therefore, we concluded that end-ischemic HOPE for split-liver transplantation can aid in recovering the graft function and reducing ischemia-reperfusion injury. HOPE, using our originally developed machine perfusion system, is safe and can improve graft function while attenuating liver injury due to preservation.

Conditioned Medium from Mesenchymal Stem Cells Alleviates Endothelial Dysfunction of Vascular Grafts Submitted to Ischemia/Reperfusion Injury in 15-Month-Old Rats

In patients undergoing coronary artery bypass grafting (CABG), ischemia/reperfusion injury (IRI) is the main contributor to organ dysfunction. Aging-induced vascular damage may be further aggravated during CABG. Favorable effects of conditioned medium (CM) from mesenchymal stem cells (MSCs) have been suggested against IRI. We hypothesized that adding CM to saline protects vascular grafts from IRI in rats. We found that CM contains 28 factors involved in apoptosis, inflammation, and oxidative stress. Thoracic aortic rings from 15-month-old rats were explanted and immediately mounted in organ bath chambers (aged group) or underwent 24 h of cold ischemic preservation in saline-supplemented either with vehicle (aged-IR group) or CM (aged-IR+CM group), prior to mounting. Three-month-old rats were used as referent young animals. Aging was associated with an increase in intima-to-media thickness, an increase in collagen content, higher caspase-12 mRNA levels, and immunoreactivity compared to young rats. Impaired endothelium-dependent vasorelaxation to acetylcholine in the aged-IR group compared to the aged-aorta was improved by CM (aged 61 ± 2% vs. aged-IR 38 ± 2% vs. aged-IR+CM 50 ± 3%, p < 0.05). In the aged-IR group, the already high mRNA levels of caspase-12 were decreased by CM. CM alleviates endothelial dysfunction following IRI in 15-month-old rats. The protective effect may be related to the inhibition of caspase-12 expression.

Hypothermic Machine Perfusion in Liver Transplantation - A Randomized Trial

BACKGROUND

Transplantation of livers obtained from donors after circulatory death is associated with an increased risk of nonanastomotic biliary strictures. Hypothermic oxygenated machine perfusion of livers may reduce the incidence of biliary complications, but data from prospective, controlled studies are limited.

METHODS

In this multicenter, controlled trial, we randomly assigned patients who were undergoing transplantation of a liver obtained from a donor after circulatory death to receive that liver either after hypothermic oxygenated machine perfusion (machine-perfusion group) or after conventional static cold storage alone (control group). The primary end point was the incidence of nonanastomotic biliary strictures within 6 months after transplantation. Secondary end points included other graft-related and general complications.

RESULTS

A total of 160 patients were enrolled, of whom 78 received a machine-perfused liver and 78 received a liver after static cold storage only (4 patients did not receive a liver in this trial). Nonanastomotic biliary strictures occurred in 6% of the patients in the machine-perfusion group and in 18% of those in the control group (risk ratio, 0.36; 95% confidence interval [CI], 0.14 to 0.94; P = 0.03). Postreperfusion syndrome occurred in 12% of the recipients of a machine-perfused liver and in 27% of those in the control group (risk ratio, 0.43; 95% CI, 0.20 to 0.91). Early allograft dysfunction occurred in 26% of the machine-perfused livers, as compared with 40% of control livers (risk ratio, 0.61; 95% CI, 0.39 to 0.96). The cumulative number of treatments for nonanastomotic biliary strictures was lower by a factor of almost 4 after machine perfusion, as compared with control. The incidence of adverse events was similar in the two groups.

CONCLUSIONS

Hypothermic oxygenated machine perfusion led to a lower risk of nonanastomotic biliary strictures following the transplantation of livers obtained from donors after circulatory death than conventional static cold storage. (Funded by Fonds NutsOhra; DHOPE-DCD ClinicalTrials.gov number, NCT02584283.).

Impact of donor and prolonged cold ischemia time of neonatal pig pancreas on neonatal pig islet transplant outcome

BACKGROUND

Genetically modified pigs (GMP) have been developed to alleviate the shortage of donors in human islet transplantation and rejection. In this study, we characterized and compared the islets from GalTKO, GalTKO/hCD46, GalTKO/hCD46/hCD39, and wild-type (WT) neonatal pigs.

METHODS

Islets were isolated from GMP and WT pig pancreases that have been packaged with ice pack for at least 24 hours. The difference in gene expression and function of islets were evaluated by microarray analysis and transplantation of islets under the kidney capsule of streptozotocin-induced diabetic immune-deficient mice, respectively. Blood glucose levels of these mice were monitored weekly post-transplantation for >100 days, and islet grafts were collected and evaluated for the presence of endocrine cells.

RESULTS

The genes involved in extracellular components, cell adhesion, glucose metabolism, and inflammatory response are differentially expressed between GMP and WT pig islets. Variation in the ability of pig islets in correcting the diabetic state of the mouse recipients appears to be dependent on the pig donor. In addition, prolonged cold ischemia time had a negative effect on the transplant outcome. All normoglycemic mice were able to respond well to glucose challenge despite the initial differences in the ability of islet transplants to reverse their diabetic state. Islet xenografts of normoglycemic mice contained abundant insulin- and glucagon-positive cells.

CONCLUSION

The effect of GMP and WT neonatal pig islet transplants on hyperglycemia in mice appears to be dependent on the pig donor, and prolonged cold ischemia time negatively affects the neonatal pig islet transplant outcome.

First Preliminary Experience with Preservation of Liver Grafts from Extended-Criteria Donors by Normothermic Machine Perfusion in Asia

BACKGROUND Normothermic machine perfusion (NMP) can provide access to evaluate and resuscitate high-risk donor livers before transplantation. The purpose of this study was to determine the efficacy of NMP in preservation and assessment of extended-criteria donor (ECD) livers in China. CASE REPORT From September 2018 to March 2019, 4 liver grafts from 3 transplant center defined as ECD were subjected to NMP, and then were transplanted successfully. During perfusion, perfusion parameters such as vascular flow, glucose level, lactate clearance, and bile production/composition were recorded to assess graft viability. All recipients were followed up 6 months after transplantation. CONCLUSIONS NMP provides a potential tool for preservation and assessment of ECD livers in China.

Protective potential effects of fucoidan in hepatic cold ischemia-rerfusion injury in rats

The necessity to increase the efficiency of organ preservation has pushed physicians to consider the use of pharmacological additives in preservation solutions to minimize ischemia reperfusion injury. Here, we evaluated the effect of fucoidan, sulfated polysaccharide from brown seaweed, as an additive to IGL-1 (Institut Georges Lopez) preservation solution. Livers from Wistar rats were preserved for 24 h at 4 °C in IGL-1 solution, enriched or not with fucoidan (100 mg/L). Thereafter, they were subjected to reperfusion (2 h, at 37 °C) using an isolated perfused rat liver model. The addition of fucoidan to IGL-1 solution reduced hepatic injury (AST, ALT) and improved liver function compared to IGL-1 solution without fucoidan. In addition, we noted a significant increase in the phosphorylation of AMPK, AKT protein kinase and GSK3-β, leading to a reduction in VDAC phosphorylation, as well as a reduction in apoptosis (caspase 3), mitochondrial damage, oxidative stress and endoplasmic reticulum (ER) stress markers. Furthermore, ERK1/2 and P38 MAPKs phosphorylation significantly decreased after supplementation of IGL-1 solution with fucoidan. In conclusion, the supplementation of IGL-1 solution with fucoidan maintained liver graft integrity and function through the prevention of the ER stress, oxidative stress and mitochondrial dysfunction. Fucoidan could be considered as potential natural therapeutic agent to alleviate graft injury.

Monitoring kidney optical properties during cold storage preservation with spatial frequency domain imaging

Transplantation of kidneys results in delayed graft function in as many as 40% of cases. During the organ transplantation process, donor kidneys undergo a period of cold ischemic time (CIT), where the organ is preserved with a cold storage solution to maintain tissue viability. Some complications observed after grafting may be due to damage sustained to the kidney during CIT. However, the effects due to this damage are not apparent until well after transplant surgery has concluded. To this end, we have used spatial frequency domain imaging (SFDI) to measure spatially resolved optical properties of porcine kidneys over the course of 80-h CIT. During this time, we observed an increase in both reduced scattering (μ s& ' ) and absorption (μa) coefficients. The measured scattering b parameter increased until 24 h of CIT, then returned toward baseline during the remaining duration of the imaging sequence. These results show that the optical properties of kidney tissue change with increasing CIT and suggest that continued investigation into the application of SFDI to kidneys under CIT may lead to the development of a noninvasive method for assessing graft viability.

The impact on the bioenergetic status and oxidative-mediated tissue injury of a combined protocol of hypothermic and normothermic machine perfusion using an acellular haemoglobin-based oxygen carrier: The cold-to-warm machine perfusion of the liver

Introduction

The combination of hypothermic and normothermic machine perfusion (HMP+NMP) of the liver provides individual benefits of both techniques, improving the rescue of marginal organs. The aim of this study was to investigate the effect on the bioenergetic status and the oxidative-mediated tissue injury of an uninterrupted combined protocol of HMP+NMP using a single haemoglobin-based oxygen carrier (HBOC)-based perfusate.

Methods

Ten discarded human donor livers had either 2 hours of dual hypothermic oxygenated perfusion (D-HOPE) with sequential controlled rewarming (COR) and then NMP using the HBOC-based perfusate uninterruptedly (cold-to-warm group); or 2 hours of hypothermic oxygenated perfusion (HOPE) with an oxygen carrier-free perfusate, followed by perfusate exchange and then NMP with an HBOC-based perfusate. Markers of liver function, tissue adenosine triphosphate (ATP) levels and tissue injury were systematically assessed.

Results

The hypothermic phase downregulated mitochondrial respiration and increased ATP levels in both groups. The cold-to-warm group presented higher arterial vascular resistance during rewarming/NMP (p = 0.03) with a trend of lower arterial flow (p = 0.09). At the end of NMP tissue expression of markers of reactive oxygen species production, oxidative injury and inflammation were comparable between the groups.

Conclusion

The uninterrupted combined protocol of HMP+NMP using an HBOC-based perfusate—cold-to-warm MP—mitigated the oxidative-mediated tissue injury and enhanced hepatic energy stores, similarly to an interrupted combined protocol; however, it simplified the logistics of this combination and may favour its clinical applicability.

The heterotopic heart transplantation in mice as a small animal model to study mechanical unloading - Establishment of the procedure, perioperative management and postoperative scoring

BACKGROUND

Unloading of failing hearts by left ventricular assist devices induces an extensive cardiac remodeling which may lead to a reversal of the initial phenotype-or to its deterioration. The mechanisms underlying these processes are unclear.

HYPOTHESIS

Heterotopic heart transplantion (hHTX) is an accepted model for the study of mechanical unloading in rodents. The wide variety of genetically modified strains in mice provides an unique opportunity to examine remodeling pathways. However, the procedure is technically demanding and has not been extensively used in this area. To support investigators adopting this method, we present our experience establishing the abdominal hHTX in mice and describe refinements to the technique.

METHODS

In this model, the transplanted heart is vascularised but implanted in series, and therefore does not contribute to systemic circulation and results in a complete mechanical unloading of the donor heart. Training followed a systematic program using a combination of literature, video tutorials, cadaveric training, direct observation and training in live animals.

RESULTS

Successful transplantation was defined as a recipient surviving > 24 hours with a palpable, beating apex in the transplanted heart and was achieved after 20 transplants in live animals. A success rate of 90% was reached after 60 transplants. Operative time was shown to decrease in correlation with increasing number of procedures from 200 minutes to 45 minutes after 60 operations. Cold/warm ischemia time improved from 45/100 to 10/20 minutes. Key factors for success and trouble shootings were identified.

CONCLUSION

Abdominal hHTX in the mouse may enable future examination of specific pathways in unloading induced myocardial remodeling. Establishment of the technique, however, is challenging. Structured training programs utilising a variety of training methods can help to expedite the process. Postoperative management, including daily scoring increases animal wellbeing and helps to predict survival.

Renal hypothermia during partial nephrectomy for patients with renal tumours: a randomised controlled clinical trial protocol

INTRODUCTION

Partial nephrectomy is a standard of care for non-metastatic renal tumours when technically feasible. Despite the increased use of partial nephrectomy, intraoperative techniques that lead to optimal renal function after surgery have not been rigorously studied. Clamping of the renal hilum to prevent bleeding during resection causes temporary renal ischaemia. The internal temperature of the kidney may be lowered after the renal hilum is clamped (renal hypothermia) in an attempt to mitigate the effects of ischaemia. Our objective is to determine if renal hypothermia during open partial nephrectomy results in improved postoperative renal function at 12 months following surgery as compared with warm ischaemia (no renal hypothermia).

METHODS AND ANALYSES

This is a multicentre, randomised, single-blinded controlled trial comparing renal hypothermia versus no hypothermia during open partial nephrectomy. Due to the nature of the intervention, complete blinding of the surgical team is not possible; however, surgeons will be blinded until the time of hilar clamping. Glomerular filtration will be based on plasma clearance of a radionucleotide, and differential renal function will be based on renal scintigraphy. The primary outcome is overall renal function at 12 months measured by the glomerular filtration rate (GFR). Secondary outcomes include change in GFR, GFR of the affected kidney, change in GFR of the affected kidney, serum creatinine, haemoglobin, spot urine albumin to creatinine ratio, quality of life and postoperative complications. Data will be collected at baseline, immediately postoperatively and at 3, 6, 9 and 12 months postoperatively.

ETHICS AND DISSEMINATION

Ethics approval was obtained for all participating study sites. Results of the trial will be submitted for publication in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT01529658; Pre-results.

The impact of the angioplasty of the renal artery and cold ischemia time in kidney transplantation on graft function

The aim of this study was to analyze the benefit of the patients after renal transplantation with an assessment of the significance of different surgical techniques in patients with renal transplantation (not only from the dead but also the living donors) with multiple arteries. 457 patients with end stage renal disease (ESRD) in the treatment using the extracorporeal elimination method (haemodialysis, or peritoneal dialysis), who in the period from 2005 to 2015 had a kidney transplant were included in our retrospective study. Our results confirm that the patients after kidney transplantation with cold ischemia time more than 12 hours have 2.5 times higher risk of delayed onset, possibly failure of graft function compared to those with cold ischemia time less than 12 hours. This confirms our experience that the best option for the patient to achieve a stable graft function with long-term perspective is cold ischemia time of less than 12 hours and the realisation of renal artery angioplasty. In this case, the risk of delayed onset of transplanted kidney function or graft failure decreases 4.5 times compared to the respondents with cold ischemia time more than 12 hours without carrying out arterial angioplasty (Tab. 1, Fig. 4, Ref. 16).

HLA-DQ Mismatching and Kidney Transplant Outcomes

BACKGROUND AND OBJECTIVES

Recent evidence suggests that HLA epitope-mismatching at HLA-DQ loci is associated with the development of anti-DQ donor-specific antibodies and adverse graft outcomes. However, the clinical significance of broad antigen HLA-DQ mismatching for graft outcomes is not well examined.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Using the United Network Organ Sharing/the Organ Procurement and Transplantation Network (UNOS/OPTN) data, patients with primary kidney transplants performed between 2005 and 2014 were included. Patients were classified as having either zero HLA-DQ mismatches, or one or two HLA-DQ mismatches. Primary outcomes were death-censored graft survival and incidence of acute rejection.

RESULTS

A total of 93,782 patients were included. Of these, 22,730 (24%) and 71,052 (76%) received zero and one or two HLA-DQ mismatched kidneys, respectively. After adjusting for variables including HLA-ABDR, HLA-DQ mismatching was associated with a higher risk of graft loss in living kidney donor recipients with an adjusted hazard ratio (HR) of 1.18 (95% confidence interval [95% CI], 1.07 to 1.30; P<0.01), but not in deceased kidney donor recipients (HR, 1.05; 95% CI, 0.98 to 1.12; P=0.18) (P value for interaction <0.01). When taking cold ischemic time into account, HLA-DQ mismatching was associated with a higher risk of graft loss in deceased kidney donor recipients with cold ischemic time ≤17 hours (HR, 1.12; 95% CI, 1.02 to 1.27; P=0.002), but not in deceased kidney donor recipients with cold ischemic time >17 hours (HR, 0.97; 95% CI, 0.88 to 1.06; P=0.49) (P value for interaction <0.01). Recipients with one or two HLA-DQ mismatched kidneys had a higher incidence of acute rejection at 1 year, with adjusted odds ratios of 1.13 (95% CI, 1.03 to 1.23; P<0.01) in deceased donor and 1.14 (95% CI, 1.03 to 1.27; P=0.02) in living donor kidney transplant recipients. Specific donor-DQ mismatches seemed to be associated with the risk of acute rejection and graft failure, whereas others did not.

CONCLUSIONS

HLA-DQ mismatching is associated with lower graft survival independent of HLA-ABDR in living donor kidney transplants and deceased donor kidney transplants with cold ischemia time ≤17 hours, and a higher 1-year risk of acute rejection in living and deceased donor kidney transplants.

Beware Cold Agglutinins in Organ Donors! Ex Vivo Lung Perfusion From an Uncontrolled Donation After Circulatory-Determination-of-Death Donor With a Cold Agglutinin: A Case Report

BACKGROUND

We began to recover lungs from uncontrolled donation after circulatory determination of death to assess for transplant suitability by means of ex vivo lung perfusion (EVLP) and computerized tomographic (CT) scan. Our first case had a cold agglutinin with an interesting outcome.

CASE REPORT

A 60-year-old man collapsed at home and was pronounced dead by Emergency Medical Services personnel. Next-of-kin consented to lung retrieval, and the decedent was ventilated and transported. Lungs were flushed with cold Perfadex, removed, and stored cold. The lungs did not flush well. Medical history revealed a recent hemolytic anemia and a known cold agglutinin. Warm nonventilated ischemia time was 51 minutes. O2-ventilated ischemia time was 141 minutes. Total cold ischemia time was 6.5 hours. At cannulation for EVLP, established clots were retrieved from both pulmonary arteries. At initiation of EVLP with Steen solution, tiny red aggregates were observed initially. With warming, the aggregates disappeared and the perfusate became red. After 1 hour, EVLP was stopped because of florid pulmonary edema. The lungs were cooled to 20°C; tiny red aggregates formed again in the perfusate. Ex vivo CT scan showed areas of pulmonary edema and a pyramidal right middle lobe opacity. Dissection showed multiple pulmonary emboli-the likely cause of death. However, histology showed agglutinated red blood cells in the microvasculature in pre- and post-EVLP biopsies, which may have contributed to inadequate parenchymal preservation.

CONCLUSIONS

Organ donors with cold agglutinins may not be suitable owing to the impact of hypothermic preservation.

Association Safety of Liver Preservation Solutions at the State University of Campinas From 2010 to 2014

The probable reason for mixing solutions during the harvesting procedure is due to the presence of multiple transplant teams that have their own solution usage tradition. Despite numerous studies comparing the efficacy of different preservation solutions, there is no study addressing the associating solution and if there is any impact on liver graft and patient survival. The aim was to evaluate the effect of the association of preservation solutions during the harvesting procedure on liver transplantation outcomes, especially in relation to the degree of preservation injury in the postreperfusion period and patient survival. We analyzed 206 transplants that were distributed as follows: when there was association (89/206 = 43.2%) and when there was no association (117/206 = 56.8%). There was a statistically significant difference in relation to the degree of preservation injury correlated to cold ischemia time (P = .009, odds ratio 1.992; 95% confidence interval 1.185-3.347). Severe harvesting (grades III and IV) was 71.8% when the solution was not associated (P = .008). There was no difference regarding patient survival either. We found that the association of liver preservation solutions has no impact on patient survival, so it can be done safely. The best survival rate was associated with minimal harvesting.

Effect of airplane transport of donor livers on post-liver transplantation survival

AIM

To evaluate the effect of long haul airplane transport of donor livers on post-transplant outcomes.

METHODS

A retrospective cohort study of patients who received a liver transplantation was performed in Perth, Australia from 1992 to 2012. Donor and recipient characteristics information were extracted from Western Australian liver transplantation service database. Patients were followed up for a mean of six years. Patient and graft survival were evaluated and compared between patients who received a local donor liver and those who received an airplane transported donor liver. Predictors of survival were determined by univariate and multivariate analysis using cox regression.

RESULTS

One hundred and ninety-three patients received a local donor liver and 93 patients received an airplane transported donor liver. Airplane transported livers had a significantly lower alanine transaminase (mean: 45 U/L vs 84 U/L, P = 0.035), higher donor risk index (mean: 1.88 vs 1.42, P < 0.001) and longer cold ischemic time (CIT) (mean: 10.1 h vs 6.4 h, P < 0.001). There was a weak correlation between CIT and transport distance (r² = 0.29, P < 0.001). Mean follow up was six years and 93 patients had graft failure. Multivariate analysis found only airplane transport retained significance for graft loss (HR = 1.92, 95%CI: 1.16-3.17). One year graft survival was 0.88 for those with a local liver and was 0.71 for those with an airplane transported liver. One year graft loss was due to primary graft non-function or associated with preservation injury in 20.8% of recipients of an airplane transported liver compared with 4.6% in those with a local liver (P = 0.027).

CONCLUSION

Airplane transport of donor livers was independently associated with reduced graft survival following liver transplantation.

Polyethylene glycols: An effective strategy for limiting liver ischemia reperfusion injury

Liver ischemia-reperfusion injury (IRI) is an inherent feature of liver surgery and liver transplantation in which damage to a hypoxic organ (ischemia) is exacerbated following the return of oxygen delivery (reperfusion). IRI is a major cause of primary non-function after transplantation and may lead to graft rejection, regardless of immunological considerations. The immediate response involves the disruption of cellular mitochondrial oxidative phosphorylation and the accumulation of metabolic intermediates during the ischemic period, and oxidative stress during blood flow restoration. Moreover, a complex cascade of inflammatory mediators is generated during reperfusion, contributing to the extension of the damage and finally to organ failure. A variety of pharmacological interventions (antioxidants, anti-cytokines, etc.) have been proposed to alleviate graft injury but their usefulness is limited by the local and specific action of the drugs and by their potential undesirable toxic effects. Polyethylene glycols (PEGs), which are non-toxic water-soluble compounds approved by the FDA, have been widely used as a vehicle or a base in food, cosmetics and pharmaceuticals, and also as adjuvants for ameliorating drug pharmacokinetics. Some PEGs are also currently used as additives in organ preservation solutions prior to transplantation in order to limit the damage associated with cold ischemia reperfusion. More recently, the administration of PEGs of different molecular weights by intravenous injection has emerged as a new therapeutic tool to protect liver grafts from IRI. In this review, we summarize the current knowledge concerning the use of PEGs as a useful target for limiting liver IRI.

Biobanking of Fresh-Frozen Human Adenocarcinomatous and Normal Colon Tissues: Which Parameters Influence RNA Quality?

Medical research projects become increasingly dependent on biobanked tissue of high quality because the reliability of gene expression is affected by the quality of extracted RNA. Hence, the present study aimed to determine if clinical, surgical, histological, and molecular parameters influence RNA quality of normal and tumoral frozen colonic tissues. RNA Quality Index (RQI) was evaluated on 241 adenocarcinomas and 115 matched normal frozen colon tissues collected between October 2006 and December 2012. RQI results were compared to patients’ age and sex, tumor site, kind of surgery, anastomosis failure, adenocarcinoma type and grade, tumor cell percentage, necrosis extent, HIF-1α and cleaved caspase-3 immunohistochemistry, and BRAF, KRAS and microsatellites status. The RQI was significantly higher in colon cancer tissue than in matched normal tissue. RQI from left-sided colonic cancers was significantly higher than RQI from right-sided cancers. The RNA quality was not affected by ischemia and storage duration. According to histological control, 7.9% of the samples were unsatisfactory because of inadequate sampling. Biobanked tumoral tissues with RQI ≥5 had lower malignant cells to stromal cells ratio than samples with RQI <5 (p <0.05). Cellularity, necrosis extent and mucinous component did not influence RQI results. Cleaved caspase-3 and HIF-1α immunolabelling were not correlated to RQI. BRAF, KRAS and microsatellites molecular status did not influence RNA quality. Multivariate analysis revealed that the tumor location, the surgical approach (laparoscopy versus open colectomy) and the occurrence of anastomotic leakage were the only parameters influencing significantly RQI results of tumor samples. We failed to identify parameter influencing RQI of normal colon samples. These data suggest that RNA quality of colonic adenocarcinoma biospecimens is determined by clinical and surgical parameters. More attention should be paid during the biobanking procedure of right-sided colon cancer or laparoscopic colectomy specimen. Histological quality control remains essential to control sampling accuracy.

[Cold ischemia and renal graft survival: A paired analysis comparing first and second grafts from the same donor]

OBJECTIVE

To compare the characteristics, clinical course, and survival of pairs of renal grafts from the same donor, with special interest in cold ischemia times (CIT) as a risk factor for graft survival.

METHODS

We retrospectively reviewed paired grafts originating from the same cadaver donor from our prospectively recorded database of kidney transplants, from 1987 to 2015. We selected and divided them into two groups depending on whether they corresponded to the first or second graft.

RESULTS

We studied a total of 860 paired kidneys. Mean CIT for the first and second groups were 15.12 and 19.16 hours, respectively. In the second group we observed higher incidences of acute tubular necrosis and initial delayed graft function (59.9% vs. 69.4% and 54.9% vs. 63.5%, respectively; p<0.001). No significant differences in either creatinine clearance rate or the rate of dialysis were observed between the two groups. No difference was found between the first and second groups in terms of graft survival (18.4 vs. 18.1 years, respectively; log-rank, p=0.667), and no differences were found by dividing the grafts into different categories according to their CIT (<14, 14-17, 17-20, >20 hours). For the set of grafts studied, CIT did not act as a risk factor for graft survival (hazard ratio [HR]=1.014; p=0.312).

CONCLUSIONS

The proportion of ATN and DGF were greater in second transplants. However, there were no differences in long-term graft survival. Furthermore, we found no evidence that a CIT for less than 24 hours acted as a risk factor to graft survival.

Development of a Pig Model for Laparoscopic Kidney Transplant

OBJECTIVES

Our aim was to describe a standardized laparoscopic kidney transplant procedure in a pig model.

MATERIALS AND METHODS

Ten pigs underwent laparoscopic kidney autotransplant. A right-hand assisted nephrectomy was performed through a Pfannenstiel incision. After the graft was washed with Ringer lactate, it was transplanted into the right iliac vessels by pure laparoscopy. To maintain cold ischemia, a gauze-wrapped ice slush was placed below the allograft. The ureteroneocystostomy was performed through the Pfannenstiel incision. The contralateral ureter was ligated at the end of the procedure. After 24 hours, pigs were killed, and the allograft's perfusion function and presence of urine in the bladder were evaluated.

RESULTS

Procedures for 2 animals (20%) could not be completed because of technical problems in the vascular anastomosis; the other 8 procedures (80%) were completed successfully. Seven allografts (87.5%) were functioning 24 hours after surgery, with urine in the bladder and good perfusion of the allograft. The other kidney presented with a venous thrombosis that was detected after death. Mean surgical times were 56.2 ± 11.7 minutes for vein anastomosis and 44.7 ± 23.1 minutes for artery anastomosis. Mean ischemia time was 193 minutes. Total duration of the procedure was clearly decreased in the last 4 animals undergoing transplant.

CONCLUSIONS

Laparoscopic transplant is a difficult procedure that requires experience in kidney laparoscopy and laparoscopic vascular sutures. The experimental model presented is a good training option and can be used to evaluate different methods to maintain cold ischemia and to compare with the traditional open approach.

Long-Term Follow-up After Right Laparoscopic Donor Nephrectomy and Inverted Kidney Transplant

OBJECTIVES

The objective of this study was to investigate the long-term outcomes of inverted kidney transplant, an alternative easy and safe technique to overcome difficulties associated with short right renal vein anastomosis after laparoscopic donor nephrectomy.

MATERIALS AND METHODS

Seventy-nine laparoscopic donor nephrectomies and intentionally inverted renal transplants were performed between 2004 and 2009. For these transplants, the renal artery was ligated by Hem-o-lok (Weck Surgical Instruments, Teleflex Medical, Durham, NC, USA) and titanium clips, and the vein was closed with 2 Hem-o-lok clips, resulting in a short renal vein. By inverting the recovered kidney to the ipsilateral pelvic side of he recipient, the short renal vein is placed posterior and adjacent to the external iliac vein; this made an easy and safe short renal vein anastomosis possible.

RESULTS

All donor nephrectomies were completed laparoscopically, and no conversion to open surgery was required. The mean warm and cold ischemic times were 7.3 minutes (range, 3.2-17.5 min) and 37.5 minutes (range, 14.2-88 min). Only 6 patients (7.6%) had delayed graft function. At 5 years after transplant, patients showed excellent graft function, with mean serum creatinine level of 1.46 mg/dL and graft survival of 93.7%. There were no occurrences of vascular thrombosis or acute rejection. However, 5 years after transplant, 4 patients had died, with 3 patients still having functional transplanted kidneys and 1 patient experiencing graft rejection 1 month before death.

CONCLUSIONS

Inverted kidney transplant is an easy and safe method to overcome the complications associated with short right renal vein anastomosis after laparoscopic donor nephrectomy. This simple modification might obviate the need to elongate a short renal vein.

Kidneys From Deceased Elderly Donors: Factors Associated With Adverse Outcomes

OBJECTIVES

We evaluated risk factors that could adversely affect outcomes from elderly deceased-donor transplants.

MATERIALS AND METHODS

In this single center retrospective study (112 patients), we studied the impact of acute rejection episodes, delayed graft function, donor-recipient age differences, HLA-DR mismatches, HLA antigen mismatches, recipient comorbidities, cold ischemia time, donor and recipient age, and donor serum creatinine level on short- and long-term graft survival.

RESULTS

Mean ages of donors and recipients were 64.71 ± 4.09 and 50.39 ± 13.72 years. Delayed graft function was 40.2%, whereas acute rejection episode rate was 38%. Graft and patient survival rates were 80.4% and 67.7%, 63.6% and 91.9%, and 82.1% and 78.2% at 1, 3, and 5 years. Cold ischemia time, recipient comorbidity, and total HLA antigen mismatch did not significantly affect graft outcome. Acute rejection episode was an independent predictor of graft outcome (β level = 2.857, t test = 2.3, P = .025). Donor age was a predictor of total graft survival duration (log-rank test gave chi-square test with 2 df = 12.292, P = .002). Donor estimated glomerular filtration rates ≥ 60 mL/min produced better outcomes than those < 60 mL/min (log-rank test gave chi-squared test with 1 df = 7.213, P = .007). Multivariate Cox regression analysis showed that donor age and delayed graft function were not significant predictors of graft outcome (P > .05), whereas acute rejection episodes (hazard ratio 5.443; 95% confidence interval, 2.226-15.311; P < .001) and donor estimated glomerular filtration rate (hazard ratio 0.449; 95% confidence interval, 0.209-0.945; P = .035) remained significant predictors of cumulative graft survival.

CONCLUSIONS

The risk factors mentioned above should be avoided to achieve better graft survival. Emphasis should not be on donor age alone. Good donor kidney function and proper immunosuppressive therapy to reduce acute rejection episodes are cornerstones to improved outcomes.

[Different techniques of vessel reconstruction in kidney transplantation 10-years experiences]

INTRODUCTION

The aim of the study was to analyze own results from Transplant Center Kosice, Slovak Republic.

METHODS

In total 457 patients in the end-stage renal failure were included to the kidney transplant program. Following techniques were used: arterioplasty, individual renal artery anastomosis and multiple renal arteries anastomosed on a common patch. The kidney transplant (Tx) especially requires surgical technique of a vascular anastomosis.

RESULTS

Renal transplantation has been established in Transplant Center Kosice since 1988. The arterioplasty of renal artery was performed in 102 (22.3%) and individual artery anastomosis in 25 (5.5%) patients. Multiple artery anastomosis on the patch was done in 43 (9.4%) and implantation of pole renal arteries to the main trunk performed in 34 (7.4%) cases.

CONCLUSION

Renal transplantation is a lifesaving method in end stage renal failure.

KEY WORDS

kidney transplantation - arterioplasty, cold ischemia time vascular anastomosis.

[The risk factors of splenic arterial steal syndrome after orthotopic liver transplantation]

OBJECTIVE

To discuss the risk factors of splenic arterial steal syndrome (SASS) after orthotopic liver transplantation.

METHODS

Twenty-four cases who confirmed SASS after liver transplantation in Tianjin First Central Hospital between June 2005 and June 2013 were analyzed retrospectively. Another 96 cases were selected randomly from those patients of the same time with no complication of SASS patients postoperatively as control group. Clinical data of two groups including diameter of splenic artery and hepatic artery preoperatively, weight of graft, weight of recipients, cold/warm ischemia time, an hepatic period and operation time and so on were collected. Others including hepatic artery peak systolic velocity (PSV), end diastolic velocity (EDV), blood flow resistance index and portal vein average velocity (PVF) on the first day after liver transplantation, the day before diagnosis, the day when diagnosed, the 1, 3, 7 days after treatment in SASS group and on 1, 3, 7, 9, 11, 14 days after liver transplantation in control group. Statistical analysis were made between two groups.

RESULTS

The splenic artery/hepatic artery ratio preoperatively and weight of donor liver,and the GRWR in SASS group and control group were 1.26 and 1.00, 1 032 g and 1 075 g, (1.40±0.30)% and (1.82±0.21)% respectively, with significantly statistical differences (Z=-6.40, Z=-2.22, t=-6.50; all P<0.05). The warm ischemia time, the cold ischemia time, the anhepatic period and operation time in SASS group and control group were 3.5 minutes and 4.0 minutes, 10.25 hours and 10.10 hours, 43 minutes and 45 minutes, 8.7 hours and 8.7 hours, with no significantly statistical differences (all P>0.05). RI of hepatic went up gradually in the early time after transplantation while dropped obviously when spleen artery spring coils embolization was received (P<0.01) and trended to stable two weeks later.

CONCLUSIONS

Splenic artery/hepatic artery ratio and GRWR are the positive and negative risk factors respectively for SASS. The gradual rising of hepatic RI in the early time after transplantation may be the warning signal SASS and spleen artery spring coils embolization is the effective strategy for SASS after liver transplantation.

Influence of perfusate on liver viability during hypothermic machine perfusion

AIM: To optimize the perfusates used for hypothermic machine perfusion (HMP).

METHODS: Sprague-Dawley rats were assigned randomly to three groups (n = 12 per group) that received either saline, University of Wisconsin cold-storage solution (UW) or histidine-tryptophan-ketoglutarate solution (HTK) as the perfusate. Each group was divided into two subgroups: static cold storage (SCS) and HMP (n = 6 per subgroup). The liver graft was retrieved according to the method described by Kamada. For the SCS group, the graft was directly placed into cold perfusate (0-4 °C) for 6 h after liver isolation while the portal vein of the graft was connected to the perfusion machine for the HMP group. Then the perfusates were collected at different time points for analysis of aspartate aminotransferase (AST), alanine transaminase (ALT) and lactate dehydrogenase (LDH) levels. Liver tissues were obtained for evaluation of histology, dry/wet weight (D/W) ratio, and malondialdehyde (MDA) and adenosine-triphosphate (ATP) levels. The portal vein pressure and velocity were monitored in real time in all HMP subgroups.

RESULTS: Comparison of HMP and SCS: Regardless of the perfusate, HMP improved the architecture of donor graft in reducing the congestion around sinusoids and central vein and maintaining sinusoid lining in morphology; HMP improved liver function in terms of ALT, AST and LDH, especially during the 3-6 h period (SCS vs HMP using saline: ALT3, 225.00 ± 105.62 vs 49.50 ± 18.50, P = 0.047; LDH3, 1362.17 ± 563.30 vs 325.75 ± 147.43, P = 0.041; UW: LDH6, 2880.14 ± 948.46 vs 2135.00 ± 174.27, P = 0.049; HTK, AST6, 307.50 ± 52.95 vs 185.20 ± 20.46, P = 0.041); HMP decreased MDA level (saline, 2.79 ± 0.30 vs 1.09 ± 0.09, P = 0.008; UW, 3.01 ± 0.77 vs 1.23 ± 0.68, P = 0.005; HTK, 3.30 ± 0.52 vs 1.56 ± 0.22, P = 0.006). Comparison among HMP subgroups: HTK showed less portal vein resistance than UW and saline (vs saline, 3.41 ± 0.49 vs 5.00 ± 0.38, P < 0.001; vs UW, 3.41 ± 0.49 vs 4.52 ± 0.63, P = 0.007); UW reduced edema most efficiently (vs saline, 0.68 ± 0.02 vs 0.79 ± 0.05, P = 0.013), while HTK maintained ATP levels best (vs saline, 622.60 ± 29.11 vs 327.43 ± 44.66, P < 0.001; vs UW, 622.60 ± 29.11 vs 301.80 ± 37.68, P < 0.001).

CONCLUSION: HMP is superior to SCS in maintaining both architecture and function of liver grafts. Further, HTK was found to be the optimal perfusate for HMP.

Long term outcomes of transplantation using kidneys from expanded criteria donors: prospective, population based cohort study

OBJECTIVES

To assess the long term outcomes of transplantation using expanded criteria donors (ECD; donors aged ≥ 60 years or aged 50-59 years with vascular comorbidities) and assess the main determinants of its prognosis.

DESIGN

Prospective, population based cohort study.

SETTING

Four French referral centres.

PARTICIPANTS

Consecutive patients who underwent kidney transplantation between January 2004 and January 2011, and were followed up to May 2014. A validation cohort included patients from another four referral centres in France who underwent kidney transplantation between January 2002 and December 2011.

MAIN OUTCOME MEASURES

Long term kidney allograft survival, based on systematic assessment of donor, recipient, and transplant clinical characteristics; preimplantation biopsy; and circulating levels of donor specific anti-HLA (human leucocyte antigen) antibody (DSA) at baseline.

RESULTS

The study included 6891 patients (2763 in the principal cohort, 4128 in the validation cohort). Of 2763 transplantations performed, 916 (33.2%) used ECD kidneys. Overall, patients receiving ECD transplants had lower allograft survival after seven years than patients receiving transplants from standard criteria donors (SCD; 80% v 88%, P<0.001). Patients receiving ECD transplants who presented with circulating DSA at the time of transplantation had worse allograft survival after seven years than patients receiving ECD kidneys without circulating DSA at transplantation (44% v 85%, P < 0.001). After adjusting for donor, recipient, and transplant characteristics, as well as preimplantation biopsy findings and baseline immunological parameters, the main independent determinants of long term allograft loss were identified as allocation of ECDs (hazard ratio 1.84 (95% confidence interval 1.5 to 2.3); P < 0.001), presence of circulating DSA on the day of transplantation (3.00 (2.3 to 3.9); P < 0.001), and longer cold ischaemia time (> 12 h; 1.53 (1.1 to 2.1); P = 0.011). Recipients of ECD kidneys with circulating DSA showed a 5.6-fold increased risk of graft loss compared with all other transplant therapies (P < 0.001). ECD allograft survival at seven years significantly improved with screening and transplantation in the absence of circulating DSA (P < 0.001) and with shorter (<12 h) cold ischaemia time (P=0.030), respectively. This strategy achieved ECD graft survival comparable to that of patients receiving an SCD transplant overall, translating to a 544.6 allograft life years saved during the nine years of study inclusion time.

CONCLUSIONS

Circulating DSA and cold ischaemia time are the main independent determinants of outcome from ECD transplantation. Allocation policies to avoid DSA and reduction of cold ischaemia time to increase efficacy could promote wider implement of ECD transplantation in the context of organ shortage and improve its prognosis.

Iliac artery aneurysm repair with preservation of a single ectopic pelvic kidney

An ultrasonographic study in a 60-year-old man incidentally detected an iliac artery aneurysm that gave rise to the renal artery of a single ectopic pelvic kidney. Renal-preservation solution could not be used during surgery, because the unclamped renal vein would have enabled the solution to enter the systemic circulation. Therefore, cold saline solution was infused through the renal ostium, and the kidney was maintained under cold saline immersion. We performed aortoiliac bypass and then implanted the renal artery into the bypass graft. Postoperatively, the patient's serum creatinine level increased; after one year, his renal function was normal. We discuss our use of cold saline solution for renal preservation.

Effects of Institut Georges Lopez-1 and Celsior preservation solutions on liver graft injury

AIM: To compare Institut Georges Lopez (IGL-1) and Celsior preservation solutions for hepatic endothelium relaxation and liver cold ischemia reperfusion injury (IRI).

METHODS: Two experimental models were used. In the first one, acetylcholine-induced endothelium-dependent relaxation (EDR) was measured in isolated ring preparations of rat hepatic arteries preserved or not in IGL-1 or Celsior solutions (24 h at 4 °C). To determine nitric oxide (NO) and cyclooxygenase EDR, hepatic arteries were incubated with L-NG-nitroarginine methyl ester (L-NAME), an inhibitor of endothelium nitric oxide synthase (eNOS), or with L-NAME plus indomethacin, an inhibitor of cyclooxygenase. In the second experiment, rat livers were cold-stored in IGL-1 or Celsior solutions for 24 h at 4 °C and then perfused “ex vivo” for 2 h at 37 °C. Liver injury was assessed by transaminase measurements, liver function by bile production and bromosulfophthalein clearance, oxidative stress by malondialdehyde levels and catalase activity and alterations in cell signaling pathways by pAkt, pAMPK, eNOS and MAPKs proteins level.

RESULTS: After cold storage for 24 h with either Celsior or IGL-1, EDR was only slightly altered. In freshly isolated arteries, EDR was exclusively mediated by NO. However, cold-stored arteries showed NO- and COX-dependent relaxation. The decrease in NO-dependent relaxation after cold storage was significantly more marked with Celsior. The second study indicated that IGL-1 solution obtained better liver preservation and protection against IRI than Celsior. Liver injury was reduced, function was improved and there was less oxidative stress. IGL-1 solution activated Akt and AMPK, which was concomitant with increased eNOS expression and nitrite/nitrate levels. Furthermore, MAPKs kinases were regulated in livers preserved with IGL-1 solution since reductions in p-p38, p-ERK and p-JNK protein levels were observed.

CONCLUSION: IGL-1 solution preserved NO-dependent relaxation better than Celsior storage solution and enhanced liver graft preservation.

Survival extrapolation using the poly-Weibull model

Recent studies of (cost-) effectiveness in cardiothoracic transplantation have required estimation of mean survival over the lifetime of the recipients. In order to calculate mean survival, the complete survivor curve is required but is often not fully observed, so that survival extrapolation is necessary. After transplantation, the hazard function is bathtub-shaped, reflecting latent competing risks which operate additively in overlapping time periods. The poly-Weibull distribution is a flexible parametric model that may be used to extrapolate survival and has a natural competing risks interpretation. In addition, treatment effects and subgroups can be modelled separately for each component of risk. We describe the model and develop inference procedures using freely available software. The methods are applied to two problems from cardiothoracic transplantation.

Sirtuin 1 in rat orthotopic liver transplantation: An IGL-1 preservation solution approach

AIM: To investigate the possible involvement of Sirtuin 1 (SIRT1) in rat orthotopic liver transplantation (OLT), when Institute Georges Lopez 1 (IGL-1) preservation solution is enriched with trimetazidine (TMZ).

METHODS: Male Sprague-Dawley rats were used as donors and recipients. Livers were stored in IGL-1 preservation solution for 8h at 4 °C, and then underwent OLT according to Kamada’s cuff technique without arterialization. In another group, livers were stored in IGL-1 preservation solution supplemented with TMZ, at 10^-6 mol/L, for 8 h at 4 °C and then underwent OLT. Rats were sacrificed 24 h after reperfusion, and liver and plasma samples were collected. Liver injury (transaminase levels), mitochondrial damage (glutamate dehydrogenase activity) oxidative stress (malondialdehyde levels), and nicotinamide adenine dinucleotide (NAD⁺), the co-factor necessary for SIRT1 activity, were determined by biochemical methods. SIRT1 and its substrates (ac-FoxO1, ac-p53), the precursor of NAD⁺, nicotinamide phosphoribosyltransferase (NAMPT), as well as the phosphorylation of adenosine monophosphate activated protein kinase (AMPK), p-mTOR, p-p70S6K (direct substrate of mTOR), autophagy parameters (beclin-1, LC3B) and MAP kinases (p-p38 and p-ERK) were determined by Western blot.

RESULTS: Liver grafts preserved in IGL-1 solution enriched with TMZ presented reduced liver injury and mitochondrial damage compared with those preserved in IGL-1 solution alone. In addition, livers preserved in IGL-1 + TMZ presented reduced levels of oxidative stress. This was consistent with enhanced SIRT1 protein expression and elevated SIRT1 activity, as indicated by decreased acetylation of p53 and FoxO1. The elevated SIRT1 activity in presence of TMZ can be attributed to the enhanced NAMPT protein and NAD⁺/NADH levels. Up-regulation of SIRT1 was consistent with activation of AMPK and inhibition of phosphorylation of mTOR and its direct substrate (p-p70S6K). As a consequence, autophagy mediators (beclin-1 and LC3B) were over-expressed. Furthermore, MAP kinases were regulated in livers preserved with IGL-1 + TMZ, as they were characterized by enhanced p-ERK and decreased p-p38 protein expression.

CONCLUSION: Our study shows that IGL-1 preservation solution enriched with TMZ protects liver grafts from the IRI associated with OLT, through SIRT1 up-regulation.

Hypothermic machine preservation facilitates successful transplantation of "orphan" extended criteria donor livers

Hypothermic machine preservation (HMP) remains investigational in clinical liver transplantation. It is widely used to preserve kidneys for transplantation with improved results over static cold storage (SCS). At our center, we have used HMP in 31 adults receiving extended criteria donor (ECD) livers declined by the originating United Network for Organ Sharing region ("orphan livers"). These cases were compared to ECD SCS cases in a matched cohort study design. Livers were matched for donor age, recipient age, cold ischemic time, donor risk index and Model for End-Stage Liver Disease (MELD) score. HMP was performed for 3-7 h at 4-8 °C using our previously published protocol. Early allograft dysfunction rates were 19% in the HMP group versus 30% in the control group (p = 0.384). One-year patient survival was 84% in the HMP group versus 80% in the SCS group (p = NS). Post hoc analysis revealed significantly less biliary complications in the HMP group versus the SCS group (4 vs. 13, p = 0.016). Mean hospital stay was significantly shorter in the HMP group (13.64 ± 10.9 vs. 20.14 ± 11.12 days in the SCS group, p = 0.001). HMP provided safe and reliable preservation in orphan livers transplanted at our center.

Polyethylene glycol rinse solution: An effective way to prevent ischemia-reperfusion injury

AIM: To test whether a new rinse solution containing polyethylene glycol 35 (PEG-35) could prevent ischemia-reperfusion injury (IRI) in liver grafts.

METHODS: Sprague-Dawley rat livers were stored in University of Wisconsin preservation solution and then washed with different rinse solutions (Ringer’s lactate solution and a new rinse solution enriched with PEG-35 at either 1 or 5 g/L) before ex vivo perfusion with Krebs-Heinseleit buffer solution. We assessed the following: liver injury (transaminase levels), mitochondrial damage (glutamate dehydrogenase activity), liver function (bile output and vascular resistance), oxidative stress (malondialdehyde), nitric oxide, liver autophagy (Beclin-1 and LCB3) and cytoskeleton integrity (filament and globular actin fraction); as well as levels of metalloproteinases (MMP2 and MMP9), adenosine monophosphate-activated protein kinase (AMPK), heat shock protein 70 (HSP70) and heme oxygenase 1 (HO-1).

RESULTS: When we used the PEG-35 rinse solution, reduced hepatic injury and improved liver function were noted after reperfusion. The PEG-35 rinse solution prevented oxidative stress, mitochondrial damage, and liver autophagy. Further, it increased the expression of cytoprotective heat shock proteins such as HO-1 and HSP70, activated AMPK, and contributed to the restoration of cytoskeleton integrity after IRI.

CONCLUSION: Using the rinse solution containing PEG-35 was effective for decreasing liver graft vulnerability to IRI.

Crucial role for neuronal nitric oxide synthase in early microcirculatory derangement and recipient survival following murine pancreas transplantation

OBJECTIVE

Aim of this study was to identify the nitric oxide synthase (NOS) isoform involved in early microcirculatory derangements following solid organ transplantation.

BACKGROUND

Tetrahydrobiopterin donor treatment has been shown to specifically attenuate these derangements following pancreas transplantation, and tetrahydrobiopterin-mediated protective effects to rely on its NOS-cofactor activity, rather than on its antioxidant capacity. However, the NOS-isoform mainly involved in this process has still to be defined.

METHODS

Using a murine pancreas transplantation model, grafts lacking one of the three NOS-isoforms were compared to grafts from wild-type controls. Donors were treated with either tetrahydrobiopterin or remained untreated. All grafts were subjected to 16 h cold ischemia time and transplanted into wild-type recipients. Following 4 h graft reperfusion, microcirculation was analysed by confocal intravital fluorescence microscopy. Recipient survival was monitored for 50 days.

RESULTS

Transplantation of the pancreas from untreated wild-type donor mice resulted in microcirculatory damage of the transplanted graft and no recipient survived more than 72 h. Transplanting grafts from untreated donor mice lacking either endothelial or inducible NOS led to similar outcomes. In contrast, donor treatment with tetrahydrobiopterin prevented microcirculatory breakdown enabling long-term survival. Sole exception was transplantation of grafts from untreated donor mice lacking neuronal NOS. It resulted in intact microvascular structure and long-term recipient survival, either if donor mice were untreated or treated with tetrahydrobiopterin.

CONCLUSION

We demonstrate for the first time the crucial involvement of neuronal NOS in early microcirculatory derangements following solid organ transplantation. In this model, protective effects of tetrahydrobiopterin are mediated by targeting this isoform.

A novel technique for resection of huge right lobe hepatocellular carcinoma extending to the right atrium: in-situ cold perfusion of liver

BACKGROUND/AIMS

Surgery for advanced hepatocellular carcinoma with inferior vena cava or right atrium extension represents challenging procedures for hepatobiliary surgeons. Regardless of the surgical approach chosen, the liver parenchyma inevitably has to suffer from ischemia during the total hepatic vascular exclusion period.

METHODOLOGY

We report our novel technique for resection of a huge hepatocellular carcinoma extending to the right atrium. During the total hepatic vascular exclusion period, in-situ cold perfusion of the liver was performed in order to minimize the ischemic insults.

RESULTS

The 53-year-old male patient with chronic hepatitis B was diagnosed to have a huge right lobe hepatocellular carcinoma, besides which the tumor had invaded the right hepatic vein and right atrium. With the help of cardio-pulmonary bypass and in-situ cold perfusion of the liver, the tumor was removed en-bloc. The operating time was 458 minutes. The cold ischemia time of the liver was 53 minutes 30 seconds. The cardio-pulmonary bypass time was 61 minutes. The estimated blood loss was about 7000 ml. The patient was discharged under stable condition on postoperative day 35.

CONCLUSIONS

In selected patients, when the expected tumor resection time is long, the in-situ cold perfusion of the liver could be considered an option.

Liver lobe graft side and outcomes in living-donor liver transplant with small-for-size grafts

OBJECTIVES

Living-donor liver transplant with small-for-size grafts (graft-to-recipient weight ratio < 0.8) may provide satisfactory results. We compared outcomes between right and left donor lobe in living-donor liver transplant.

MATERIALS AND METHODS

Patients who had living-donor liver transplant from 2006 to 2008 with graft-to-recipient weight ratio < 0.8 (graft: right lobe, 24 patients; left lobe, 26 patients) were reviewed retrospectively.

RESULTS

There were no significant differences in demographic and preoperative clinical data between patients who received a right or left lobe liver graft. Duration of surgery was longer, cold ischemia time was shorter, and mean baseline portal vein flow was greater in transplants performed with left than right donor lobes. Portal vein flow modulation with splenectomy was performed when portal flow was > 250 mL/min/100 g graft. Small-for-size syndrome was observed in 6 recipients (14%), but no patient who developed small-for-size syndrome developed liver failure or required revision transplant. The frequency of small-for-size syndrome was significantly greater in patients who had left lobe (4 patients [15%]) than right lobe transplant (2 patients [8%]; P ≤ .05). Graft dysfunction-free survival was significantly greater with right than left lobe grafts. In multivariate analysis, graft side was the only significant risk factor for small-for-size syndrome.

CONCLUSIONS

In patients having living-donor liver transplant with small-for-size grafts, outcome was better with right than left lobe grafts.