Development status and new challenges of heart transplantation / 器官移植

Heart transplantation is the primary therapeutic option for patients with end-stage heart failure. The shortage of donors has been the main limiting factor for the increasing quantity of heart transplantation. With persistent updating and introduction of novel technologies, the donor pool has been increasingly expanded, such as using the heart from older donors, donors infected with hepatitis C virus, donors dying from drug overdose or donation after cardiac death (DCD) donors, etc. Meantime, the proportion of recipients with advanced age, multiple organ dysfunction, mechanical circulatory support and human leukocyte antigen antibody sensitization has been significantly increased in recent years. The shortage of donors, complication of recipients' conditions, individualized management of immunosuppressive therapy and prevention and treatment of long-term cardiac allograft vasculopathy are all challenges in the field of heart transplantation. In this article, novel progresses on donor pool expansion, improving the quality of recipients, strengthening the diagnosis and treatment of rejection, and preventing cardiac allograft vasculopathy were reviewed, aiming to prolong the survival and enhance the quality of life of patients with end-stage heart failure on the waiting list or underwent heart transplantation.

Application of a novel artificial perfusate based on oxygen-carrying nanoparticles in normothermic machine perfusion for porcine liver preservation after cardiac death / 浙江大学学报·医学版

OBJECTIVE@#To investigate the efficacy of a novel artificial perfusate based on oxygen-carrying perfluoronaphthalene-albumin nanoparticles in normothermic machine perfusion (NMP) for preservation of porcine liver donation after cardiac death.@*METHODS@#Artificial perfusate with perfluoronaphthalene-albumin nanoparticles was prepared at 5% albumin (w/v) and its oxygen carrying capacity was calculated. The livers of 16 Landrace pigs were isolated after 1 h of warm ischemia, and then they were divided into 4 groups and preserved continuously for 24 h with different preservation methods: cold preservation with UW solution (SCS group), NMP preservation by whole blood (blood NMP group), NMP preservation by artificial perfusate without nanoparticles (non-nanoparticles NMP group) and NMP preservation by artificial perfusate containing nanoparticles (nanoparticles NMP group). Hemodynamics, tissue metabolism, biochemical indices of perfusate and bile were monitored every 4 h after the beginning of NMP. Liver tissue samples were collected for histological examination (HE and TUNEL staining) before preservation, 12 h and 24 h after preservation.@*RESULTS@#The oxygen carrying capacity of nanoparticles in 100 mL artificial perfusate was 6.94 μL/mmHg (1 mmHg=0.133 kPa). The hepatic artery and portal vein resistance of nanoparticles NMP group and blood NMP group remained stable during perfusion, and the vascular resistance of nanoparticles NMP group was lower than that of blood NMP group. The concentration of lactic acid in the perfusate decreased to the normal range within 8 h in both nanoparticles NMP group and blood NMP group. There were no significant differences in accumulated bile production, alanine aminotransferase and aspartate aminotransferase in perfusate between nanoparticles NMP group and blood NMP group (all P>0.05). After 24 h perfusion, the histological Suzuki score in blood NMP group and nanoparticles NMP group was lower than that in SCS group and non-nanoparticles NMP group (all P<0.05), and the quantities of TUNEL staining positive cells in blood NMP group and non-nanoparticles NMP group was higher than those in nanoparticles NMP group and SCS group 12 h and 24 h after preservation (all P<0.05).@*CONCLUSION@#Artificial perfusate based on oxygen-carrying nanoparticles can meet the oxygen supply requirements of porcine livers donation after cardiac death during NMP preservation, and it may has superiorities in improving tissue microcirculation and alleviating ischemia-reperfusion injury.

Research advances of liver machine perfusion / 中华器官移植杂志

This review evaluated the current research status and the latest advances of liver machine perfusion, aiming to provide references for researchers and clinicians in related fields.

Evaluating and repairing biliary injury during normothermic liver perfusion / 中华器官移植杂志

A widening gap between demand and availability of donor livers for transplantation has stimulated the use of extended-criteria donor(ECD)livers, including donation after circulatory death liver grafts.However, these types of donor livers carry an elevated risk of developing such postoperative complication as ischemic type biliary lesions(ITBL).Although the pathogenesis of ITBL has remained elusive, severity of histological bile duct injury(BDI)at the time of transplantation has been identified as a strong predictor of the development of ITBL post-transplantation.In recent years, significant advances have been achieved in the field of liver machine perfusion.Normothermic machine perfusion(NMP)is primarily utilized for determining the quality of ECD organs.To evaluate the extent of biliary injury during NMP, some reliable criteria of BDI are required.This review focused upon different approaches of assessing damage to biliary tree and current understandings of potential effects of NMP on biliary system and biliary injury.Also it offered an overview of novel biomarkers and emerging therapeutic strategies.

Normothermic machine perfusion of kidney and ischemia-free kidney transplantation / 器官移植

To increase the utilization rate of expanded criteria donor (ECD) kidney, the kidney preservation methods have been ever advancing in recent years. The application of normothermic machine perfusion (NMP) promotes the preservation, evaluation and repair of ex vivo donor kidneys and accelerates the innovation of surgical approaches of kidney transplantation. Ischemia-free kidney transplantation (IFKT), which initiated by Organ Transplantation Center of the First Affiliated Hospital of Sun Yat-sen University, keeps the blood flow and oxygen supply of the donor kidney with NMP machine during the entire process of acquisition, preservation and transplantation, thereby fundamentally avoiding ischemia-reperfusion injury (IRI) of the donor kidney and reducing the risk of delayed graft function (DGF) and acute rejection after surgery. In this article, recent progresses upon the kidney NMP, surgical procedures and short-term outcomes of IFKT were reviewed, aiming to provide reference for enhancing the utilization rate of ECD donor kidney and resolving the issue of organ shortage.

Effect of BMMSCs on steatosis of DCD donor liver in SD rats by normothermic machine perfusion / 中华肝胆外科杂志

Objective:To investigate the role of ferroptosis in bone marrow mesenchymal stem cells (BMMSCs) combine with normothermic machine perfusion (NMP) in repairing steatotic liver donor after cardiac death (DCD) in SD rats.Methods:BMMSCs were derived from SD rats to establish the DCD model of rats steatotic liver. A total of 24 rats were randomly divided into four groups: simple steatotic liver model group (Sham), static cold storage group (SCS), NMP, BMMSCs combine with NMP preservation group (BNMP), and the preservation time was 4 hours. The donor liver function was evaluated by liver structure, liver enzymes and lactic acid content of perfusion fluid, bile secretion and inflammatory cytokines; furthermore, in order to evaluate the occurrence of liver ferroptosis, the content of Fe 2+, malondialdehyde and glutathione (GSH) in liver tissue, as well as the mRNA or protein expression changes of cyclooxygenase-2 (COX-2), prostaglandin-endoperoxide synthase 2 (Ptgs2), glutathione peroxidase 4 (GPX4) and ferritin heavy chain 1 (FTH1) were detected. Results:After DCD steatotic donor liver was preserved for 4 hours, the liver injury, pro-inflammatory and anti-inflammatory cytokines expression in the BNMP and NMP groups were better than those in the SCS group. During the machine perfusion preservation period, alanine aminotransferase [(189.0±12.5)U/L vs. (227.7±16.2)U/L], aspartate aminotransferase [(207.3±18.6)U/L vs. (247.0±11.8)U/L] and lactic acid [(2.3±0.3)mmol/L vs. (2.9±0.2)mmol/L] in the BNMP group is lower than those in NMP group, moreover, the amount of hepatic bile secretion in the BNMP group [(1 245.7±46.8) μl vs. (1 014.3±67.9) μl] was more than that in NMP group, the difference was statistically significant (all P<0.05). The content of Fe 2+ and malondialdehyde in the liver tissue of BNMP group was significantly lower than those of SCS and NMP groups, on the contrary, the content of GSH was significantly higher than those of SCS and NMP groups. In addition, in the BNMP group, the mRNA level of Ptgs2 and protein level of COX-2 in the liver were significantly reduced, and expression of GPX4 and FTH1 were significantly higher than those of NMP and SCS groups, the differences were statistically significant (all P<0.05). Conclusion:BMMSCs combine with normothermic machine perfusion can better repair SD rats DCD steatotic donor liver and its mechanism of action may be related to its regulation on liver ferroptosis.

Effect of heme oxygenase-1 modified bone marrow mesenchymal stem cells combined with normothermic machine perfusion on intestinal barrier function in Brown Norway rats with acute rejection of liver transplantation / 中华肝胆外科杂志

Objective:To investigate the effect of heme oxygenase-1 (HO-1) modified bone marrow mesenchymal stem cells (BMMSCs) combined with normothermic machine perfusion (NMP) on the intestinal barrier function in rats with acute rejection of liver transplantation.Methods:Specific pathogen free 2 male Brown Norway (BN) rats (4-5 weeks, 40-60 g) were used to isolat BMMSCs, and HO-1 was infected by adenovirus. Of 24 male Lewis rats (7-8 weeks old, 200-220g) were used as donors, 30 male BN rats (8-9 weeks old, 220-240 g) were used as recipients. Acute rejection models of orthotopic liver transplantation were established in rats using two cuff technique. BN recipient rats were randomly divided into five groups: sham group, abdomen of the mice was open and closed within 30 min; NMP livers were simply mechanically perfused for 4 h; the BMP group were perfused with BMMSCs through the portal vein; the HBP group were perfused with HO-1/BMMSCs through the portal vein; the FK506 livers were mechanically perfused for 4 h and administered intragastrically of tacrolimus daily following surgery, 6 per group, on days 14 after surgery, the relevant indicators were taken and the rejection activity index (RAI) changes were investigated. The changes of intestinal pathological were analyzed by HE staining and transmission electron microscope, the expression levels of zonula occludens-1 (ZO-1) and occludin protein in intestinal tissue were detected by Western blotting, the concentrations of lipopolysaccharide, D-lactic acid and diamine oxidase (DAO) in serum were detected by ELISA.Results:The RAI of HBP group (2.80±0.84) and FK506 group (2.20±0.84) were significantly lower than that of NMP group (7.60±1.14) and BMP group (6.00±1.58), the differences were statistically significant (all P<0.05). The intestinal villi in NMP group were significantly sparse, wrinkled and disorderly arranged while the degree of intestinal injury in BMP group, HBP group and FK506 group were more mitigated. Electron microscope observation showed that the microvilli of intestinal epithelial cells in HBP group were rich and orderly, and the tight junction structure between cells was complete. The protein expression levels of ZO-1 and Occludin in the intestinal tissues of HBP group [(0.87±0.06) (1.28±0.26)] were higher than those of NMP group [(0.41±0.12) (0.27±0.18)] and FK506 group [(0.52±0.15) (0.63±0.22)], the differences were statistically significant (all P<0.05). The concentration of lipopolysaccharide, D-lactic acid and DAO in serum of HBP group was lower than those of NMP group and FK506 group, the differences were statistically significant (all P<0.05). Conclusion:HO-1/BMMSCs combined with NMP protects the intestinal mucosal barrier function of BN rats with acute rejection after liver transplantation.

Mechanisms of bone marrow mesenchymal stem cells plus normothermic mechanical perfusion alleviating hepatocyte apoptosis after donation after cardiac death transplantation in rats / 中华器官移植杂志

Objective:To explore the effect and possible mechanism of normal temperature mechanical perfusion(NMP)plus bone marrow mesenchymal stem cells(BMMSCs)on early endoplasmic reticulum stress(ERs)and cellular apoptosis after donation after cardiac death(DCD)donor liver transplantation.Methods:BMMSCs were isolated and cultured by adherence method.Sixty Sprague-Dawley(SD)rats were randomly divided into five groups of sham operation(sham), static cold storage(SCS), NMP, BMMSC and NMP plus BMMSCs(BP)( n=12 each). Liver tissue and serum sample of each group were harvested at Day 1/7 post-operation.Hematoxylin-eosin(HE)staining was employed for observing pathological changes of liver tissue; TdT-mediated dUTP nick end labeling(TUNNEL)staining for detecting cellular apoptosis; immunohistochemistry for detecting the expression of hepatocyte transcription factor C/EBP homologous protein(CHOP); Western blot for detecting the expressions of GRP-78, p-PERK, ATF4, CHOP and cleaved caspase-3. Results:Compared with SCS group, hepatic injury and inflammation significantly declined in NMP, BMMSC and BP groups and improvement of hepatic injury was the most pronounced in BP group.Cellular apoptosis lessened markedly in BP group at Day 1/7 as compared with SCS group and the difference was statistically significant.The expressions of ERs-related proteins GRP-78, p-PERK and ATF4 spiked in SCS group and the expressions of pro-apoptotic proteins CHOP and cleaved caspase-3 were significantly elevated and declined markedly in BP group.And the difference was statistically significant.Conclusions:BMMSCs plus NMP can significantly improve hepatocyte apoptosis and inflammatory response after DCD donor liver transplantation.And its mechanism may be correlated with suppressing early endoplasmic reticulum stress of hepatocytes.

Exploration on the experience of long-term external normothermic machine perfusion of discarded human kidney for the first time in China / 中华肾脏病杂志

Objective:To explore the long-term preservation value and repair effect of normothermic machine perfusion (NMP) on clinically discarded kidneys.Methods:A case of clinical discarded donor kidney was collected, and NMP was carried out in vitro for 9 hours with recovered blood. The dynamic changes of renal appearance, blood gas and biochemistry analysis of perfusate and renal pathology were recorded. Results:In the second to fifth hour of NMP, the appearance of renal was pink and ex vivo normothermic perfusion assessment score (EVNP) was grade Ⅰ. While, the sixth hour and beyond of NMP, the appearance of kidney turned to dark red and EVNP was grade Ⅲ. The renal perfusion blood flow maintained above 150 ml/min in the first 6 hours and decreased significantly after that, and at the end, was only 50 ml/min. During the whole process of perfusion, urine output was maintained at about 100 ml/h. PO 2 remained above 100 mmHg in the first 5 hours of perfusion and from the 6th hour, was lower than 80 mmHg and continued to decline, and was close to 0 at the end of perfusion. The results showed that although the K + concentration changes in blood and urine in the first 5 hours of NMP had a good consistency, the lactic acid level had been rising. In addition, there was no significant change in the histopathology at the fourth hour of perfusion compared with that before zero-point puncture, and the fibrinous thrombus in glomeruli was improved compared with that before perfusion. However, at the sixth hour after perfusion and before the end of perfusion, the pathological changes of renal tissue were significantly worse. There were a large of thrombosis in glomerular blood vessels, renal tubular atrophy and acute tubular necrosis. Conclusions:NMP can realize the evaluation of extended criteria donors before transplantation, and it proves the feasibility and repair potential of NMP in kidney to a certain extent. At the same time, NMP also provides a new way to expand the source of donor kidney and to pre-treat organ in vitro.

Development of Liver Normothermic Machine Perfusion Repair and Assessment System / 中国医疗器械杂志

This paper introduced a liver normothermic machine perfusion repair and assessment system. This system consists of a liver normothermic machine perfusion device, a fluorescence imaging system and a tissue oxygen detector. The normothermic machine perfusion device can continuously perfuse the donor liver and monitor and control the perfusion parameters in real time. The fluorescence imaging system can detect the indocyanine green metabolized by the liver to evaluate the microcirculation and the metabolism function of hepatocytes. The tissue oxygen detector can monitor the change of oxygen partial pressure of liver tissue in real time to evaluate the state of cell oxygen consumption.

Supercooling organ preservation technology and its application / 器官移植

The main purpose of organ preservation in organ transplantation is to maintain tissue and cell activity of donor organs so as to gain time for allocation and transportation of the organ, preparation of the recipient and organization of staff and facilities. The main principles of organ preservation can be divided into normothermic mechanical perfusion and cryopreservation. Cryopreservation is the favourite organ preservation method in clinical practice currently. However, the metabolic activity still exists in donor organs preserved with current cryopreservation technique, which makes the long-term preservation of organs extremely difficult. The supercooling organ preservation is a new type of cryopreservation technology, which greatly prolongs the preservation time of organs. It is expected to become an important organ preservation technique in the future, and it will provide technical support for the establishment of "organ bank".

Ischemia-free liver transplantation (Reports of 3 cases) / 中华器官移植杂志

Objective Ischemia reperfusion injury (IRI) is a major limiting factor of graft survival in organ transplantation.We've established a novel procedure called ischemia-free liver transplantation (IFLT) in big animal study.In this report,we aimed to investigate the feasibility and early outcomes of IFLT.Methods We have performed 3 cases of IFLT during July 23,2017 to August 9,2017.We analyzed the surgical methods,normothermic perfusion parameters,blood gas analysis,liver function tests and complications early after liver transplantation.Pathologic studies and immunohistochemical staining of donor liver biopsies were conducted before procurement,at the end of machine perfusion,as well as after re-vascularization for evaluating IRI.Results The surgical procedures of all 3 patients were successful,without stoppage of blood supply for the liver grafts throughout organ procurement,ex vivo preservation and implantation.During normothermic perfusion,the pH value was stable within the normal range and the lactate levels dropped quickly to lower than detected (＜0.3 mmol/L) within 1.5-3 h.The livers continued to produce bile with the volume of 2-6 mL/h.Hematoxylin and eosin (HE) staining evaluation and TdT-mediated dUTP nick end labeling (TUNEL) assay of biopsies taken from liver tissues before procurement,at the end of machine perfusion and after re-vascularization,showed few necrostic and apoptotic hepatocytes in the liver biopsies.The immunohistochemical staining of IL-1β and vWF suggested no inflammatory cytokine release and sinusoidal endothelial cell activation.The three patients recovered smoothly without rejection,vascular and biliary complications.Conclusion IFLT is a feasible and effective procedure,which is able to overcome the major limitations of conventional procedure.The novel IFLT will become one of the mainstream transplant procedures in the future.

Establishment of a split liver transplantation pig model using extracorporeal normothermic machine perfusion / 中华肝胆外科杂志

Objective To summarize the experience of establishing a split liver transplantation pig model using extracorporeal normothermic machine perfusion (NMP).Methods Twenty miniature pigs were purchased with ten as donors and another ten as receptors.The graft was spliced along Taira line and the right half was reserved for transplantation.Hemodynamics and bile production volume were monitored,and blood biochemical and blood gas analysis indicators were detected during machine perfusion.Pathological change was observed by HE stain.Hemodynamics during liver transplantation,5-day survival rate and the cause of death were recorded.Results Hemodynamic,biochemical and blood gas analysis indicators remained stable during NMP.All receptor pigs were successfully extubated and awake after surgery.Two receptors died on the second day after the operation.The 5-day survival rate was 80％.Conclusion The split liver transplantation pig model using extracorporeal normothermic machine perfusion is feasible and appropriate,and it lays the foundation for further investigation.