Organ preservation in pancreas and islet transplantation. Curr Opin Organ Transplant. 2008;13:59-66. [PMID: 18660708 DOI: 10.1097/mot.0b013e3282f44a63]

Dexmedetomidine's Effects on the Livers and Kidneys of Rats with Pancreatic Ischemia-Reperfusion Injury

Objective

Pancreatic surgeries inherently cause ischemia-reperfusion (IR) injury, affecting not only the pancreas but also distant organs. This study was conducted to explore the potential use of dexmedetomidine, a sedative with antiapoptotic, anti-inflammatory, and antioxidant properties, in mitigating the impacts of pancreatic IR on kidney and liver tissues.

Methods

A total of 24 rats were randomly divided into four groups: control (C), dexmedetomidine (D), ischemia reperfusion (IR), and dexmedetomidine ischemia reperfusion (D-IR). Pancreatic ischemia was induced in the IR and D-IR groups. Dexmedetomidine was administered intraperitoneally to the D and D-IR groups. Liver and kidney tissue samples were subjected to microscopic examinations after hematoxylin and eosin staining. The levels of thiobarbituric acid reactive substances (TBARS), aryllesterase (AES), catalase (CAT), and glutathione S-transferase (GST) enzyme activity were assessed in liver and kidney tissues. The serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), blood urea nitrogen (BUN), and creatinine were measured.

Results

A comparison of the groups revealed that the IR group exhibited significantly elevated TBARS (p < 0.0001), AES (p = 0.004), and CAT enzyme activity (p < 0.0001) levels in the liver and kidney compared to groups C and D. Group D-IR demonstrated notably reduced histopathological damage (p < 0.05) and low TBARS (p < 0.0001), AES (p = 0.004), and CAT enzyme activity (p < 0.0001) in the liver and kidney as well as low AST and ALT activity levels (p < 0.0001) in the serum compared to the IR group.

Conclusion

The preemptive administration of dexmedetomidine before pancreatic IR provides significant protection to kidney and liver tissues, as evidenced by the histopathological and biochemical parameters in this study. The findings underscored the potential therapeutic role of dexmedetomidine in mitigating the multiorgan damage associated with pancreatic surgeries.

Ischemia-Reperfusion Injuries Assessment during Pancreas Preservation

Maintaining organ viability between donation and transplantation is of critical importance for optimal graft function and survival. To date in pancreas transplantation, static cold storage (SCS) is the most widely practiced method of organ preservation. The first experiments in ex vivo perfusion of the pancreas were performed at the beginning of the 20th century. These perfusions led to organ oedema, hemorrhage, and venous congestion after revascularization. Despite these early hurdles, a number of factors now favor the use of perfusion during preservation: the encouraging results of HMP in kidney transplantation, the development of new perfusion solutions, and the development of organ perfusion machines for the lung, heart, kidneys and liver. This has led to a resurgence of research in machine perfusion for whole organ pancreas preservation. This review highlights the ischemia-reperfusion injuries assessment during ex vivo pancreas perfusion, both for assessment in pre-clinical experimental models as well for future use in the clinic. We evaluated perfusion dynamics, oedema assessment, especially by impedance analysis and MRI, whole organ oxygen consumption, tissue oxygen tension, metabolite concentrations in tissue and perfusate, mitochondrial respiration, cell death, especially by histology, total cell free DNA, caspase activation, and exocrine and endocrine assessment.

Effect of volatile anesthetics on early and delayed outcomes in pancreas transplantation

BACKGROUND

Ischemia-reperfusion injury (IRI) is a common cause of allograft dysfunction and patient morbidity in solid organ transplantation. This study compares the effect of different inhaled anesthetics on early IRI and clinical outcomes in pancreas allograft recipients.

METHODS

Data were extracted retrospectively for pancreas transplants at a single center over a 15-year period. Early postoperative pancreatic amylase and lipase levels were used as a marker for graft injury. Clinical outcomes measured included length of hospital stay, readmission, and graft survival.

RESULTS

There were 625 pancreas transplants included in the analysis with 3 primary inhaled anesthetics: sevoflurane (53%), desflurane (35%), and isoflurane (12%). In the first 30 days post-transplant, peak amylase was lowest for sevoflurane (147) followed by desflurane (159) and isoflurane (229) (p = .03). Peak lipase levels followed the same trend (peak values 118, 131, and 135, respectively; p = .02). Early graft loss, length of hospital stay, and readmission within 3 months were similar among all three anesthetic groups. There was no difference in 10-year graft survival by Cox regression.

CONCLUSIONS

Sevoflurane and desflurane are associated with lower peak amylase and lipase levels postoperatively in pancreas transplantation. Short- and long-term clinical outcomes were equivalent for the three agents.

Complications during multiorgan retrieval and pancreas preservation

In pancreas transplantation, complications can arise at each step of the process, from the initial selection of donors and recipients through the surgical technique itself and the post-operative period, when lifelong immunosuppression is required. In the early steps, careful retrieval and preservation of the pancreas are crucial for the viability of the organ and ultimate success of the transplant. The pancreas is a low-flow gland, making it highly sensitive to transplantation conditions and presenting risk of pancreatitis due to periods of ischemia. The two groups of donors - after brain death (DBD) or after cardiac arrest (DCD) - require different strategies of retrieval and preservation to avoid or reduce the risk of complications developing during and after the transplantation. For DBD donor transplantation, multiorgan retrieval and cold preservation is the conventional technique. Asystole donor (DCD) transplantation, in contrast, can benefit from the newest technologies, such as hypothermic and especially normothermic preservation machines (referred to as NECMO), to optimize organ preservation. The latter has led to an increase in the pool of donors by facilitating recuperation of organs for transplantation that would have been discarded otherwise.

Ex situ hypothermic perfusion of nonhuman primate pancreas: A feasibility study

Pancreatic static cold storage (SCS) is the gold-standard method for pancreas preservation. Our main objective was to evaluate feasibility of hypothermic perfusion (HP) of nonhuman primates' pancreases for potential organ transplantation. Seven baboon pancreases were tested. Animals were included in a study approved by the French Research Ministry of Health. Two groups were compared: the control group (n = 2) was preserved using conventional SCS for 24-h and the perfusion group (n = 5) used HP for 24-h, with three different perfusion pressures (PP): 15 (n = 3), 20 (n = 1), and 25 mm Hg (n = 1). In the control group, focal congestion of islets was observed after 6-h. At 24-h, ischemic necrosis and multifocal congestion also occurred. In the HP group, at 15 mm Hg PP, multifocal congestion of islets was present at 24-h. At 20 mm Hg PP, no ischemic necrosis was found after 6-h. At 12-h and 24-h, focal congestion of islets was seen. At 25 mm Hg PP, focal congestion of islets appeared after 12-h. Immunostaining for insulin, glucagon, and somatostatin was normal and similar in controls and perfused pancreas transplants even after 24-h. Apoptosis index represented by cleaved caspase 3 activity, was less than 1% in perfusion and control groups, even after 24-h. HP of nonhuman primate pancreas is feasible and not deleterious as far as 24-h compared to SCS. SCS for more than 12-h was harmful for the transplants. Systolic perfusion pressure between 15-20 mm Hg did not cause any pathological injury of the tested organs.

Hypothermic pulsatile perfusion of human pancreas: Preliminary technical feasibility study based on histology

BACKGROUND

There are currently two approaches to hypothermic preservation for most solid organs: static or dynamic. Cold storage is the main method used for static storage (SS), while hypothermic pulsatile perfusion (HPP) and other machine perfusion-based methods, such as normothermic machine perfusion and oxygen persufflation, are the methods used for dynamic preservation. HPP is currently approved for kidney transplantation.

METHODS

We evaluated, for the first time, the feasibility of HPP on 11 human pancreases contraindicated for clinical transplantation because of advanced age and/or history of severe alcoholism and/or abnormal laboratory tests. Two pancreases were used as SS controls, pancreas splitting was performed on 2 other pancreases for SS and HPP and 7 pancreases were tested for HPP. HPP preservation lasted 24 h at 25 mmHg. Resistance index was continuously monitored and pancreas and duodenum histology was evaluated every 6 h.

RESULTS

The main finding was the complete absence of edema of the pancreas and duodenum at all time-points during HPP. Insulin, glucagon and somatostatin staining was normal. Resistance index decreased during the first 12 h and remained stable thereafter.

CONCLUSION

24 h hypothermic pulsatile perfusion of marginal human pancreas-duodenum organs was feasible with no deleterious parenchymal effect. These observations encourage us to further develop this technique and evaluate the safety of HPP after clinical transplantation.

Human Endothelial Protein C Receptor Overexpression Protects Intraportal Islet Grafts in Mice

Islet transplantation can potentially cure type 1 diabetes mellitus, but it is limited by a shortage of human donors as well as by islet graft destruction by inflammatory and thrombotic mechanisms. A possible solution to these problems is to use genetically modified pig islets. Endothelial protein C receptor (EPCR) enhances protein C activation and regulates coagulation, inflammation, and apoptosis. We hypothesized that human EPCR (hEPCR) expression on donor islets would improve graft survival and function. Islets from an hEPCR transgenic mouse line strongly expressed the transgene, and hEPCR expression was maintained after islet isolation. Islets were transplanted from hEPCR mice and wild-type (WT) littermates into diabetic mice in a marginal-dose syngeneic intraportal islet transplantation model. The blood glucose level normalized within 5 days in 5 of 7 recipients of hEPCR islets, compared with only 2 of 7 recipients of WT islets (P < .05). Transplanted hEPCR islets had better preserved morphology and more intense insulin staining than WT grafts, and they retained transgene expression. The improved engraftment compared with WT islets suggests that inflammation and coagulation associated with the transplant process can be reduced by hEPCR expression on donor tissue.

Retrieval of the pancreas allograft for whole-organ transplantation

Proper pancreas retrieval during multi-organ recovery is one of the cornerstones of technically successful whole-organ pancreas transplantation. With evolving surgical approaches for organ retrieval and implantation, it has become standard to procure the pancreas in conjunction with other abdominal organs without compromising either vasculature, graft quality, or transplant outcomes. This review summarizes the major steps required for proper whole-organ retrieval of the pancreas allograft with suggestions and tips whenever alternative approaches are available.

Beyond poiseuille: preservation fluid flow in an experimental model

Poiseuille's equation describes the relationship between fluid viscosity, pressure, tubing diameter, and flow, yet it is not known if cold organ perfusion systems follow this equation. We investigated these relationships in an ex vivo model and aimed to offer some rationale for equipment selection. Increasing the cannula size from 14 to 20 Fr increased flow rate by a mean (SD) of 13 (12)%. Marshall's hyperosmolar citrate was three times less viscous than UW solution, but flows were only 45% faster. Doubling the bag pressure led to a mean (SD) flow rate increase of only 19 (13)%, not twice the rate. When external pressure devices were used, 100 mmHg of continuous pressure increased flow by a mean (SD) of 43 (17)% when compared to the same pressure applied initially only. Poiseuille's equation was not followed; this is most likely due to “slipping” of preservation fluid within the plastic tubing. Cannula size made little difference over the ranges examined; flows are primarily determined by bag pressure and fluid viscosity. External infusor devices require continuous pressurisation to deliver high flow. Future studies examining the impact of perfusion variables on graft outcomes should include detailed equipment descriptions.

Beneficial effects of ischemic preconditioning on pancreas cold preservation

Ischemic preconditioning (IPC) confers tissue resistance to subsequent ischemia in several organs. The protective effects are obtained by applying short periods of warm ischemia followed by reperfusion prior to extended ischemic insults to the organs. In the present study, we evaluated whether IPC can reduce pancreatic tissue injury following cold ischemic preservation. Rat pancreata were exposed to IPC (10 min of warm ischemia followed by 10 min of reperfusion) prior to ~18 h of cold preservation before assessment of organ injury or islet isolation. Pancreas IPC improved islet yields (964 ± 336 vs. 711 ± 204 IEQ/pancreas; p = 0.004) and lowered islet loss after culture (33 ± 10% vs. 51 ± 14%; p = 0.0005). Islet potency in vivo was well preserved with diabetes reversal and improved glucose clearance. Pancreas IPC reduced levels of NADPH-dependent oxidase, a source of reactive oxygen species, in pancreas homogenates versus controls (78.4 ± 45.9 vs. 216.2 ± 53.8 RLU/μg; p = 0.002). Microarray genomic analysis of pancreata revealed upregulation of 81 genes and downregulation of 454 genes (greater than twofold change) when comparing IPC-treated glands to controls, respectively, and showing a decrease in markers of apoptosis and oxidative stress. Collectively, our study demonstrates beneficial effects of IPC of the pancreas prior to cold organ preservation and provides evidence of the key role of IPC-mediated modulation of oxidative stress pathways. The use of IPC of the pancreas may contribute to increasing the quality of donor pancreas for transplantation and to improving organ utilization.

Preservation of human placenta facilitates multicenter studies on the local immune response in normal and aberrant pregnancies

Our standard procedure for phenotypic and functional analysis of immune cells present in the placenta is to isolate leukocytes from the decidua within five hours of the delivery. However, this results in logistical problems with deliveries at night, weekends or in other medical centers. Collecting placentas after complicated pregnancies is even more difficult owing to the low prevalence and the often unscheduled delivery. The aim was to investigate the possibility of preserving the human placenta before phenotypic and functional analysis of decidual lymphocytes. Placentas were obtained after uncomplicated pregnancy. The tissue was divided into two equal parts: decidual lymphocytes from one part were isolated within five hours according to our standard procedure, whereas the other part was preserved in either Celsior(®), a storage solution for solid organ preservation, or phosphate-buffered saline (PBS) for 24h at 4°C before isolation. Overall, the phenotype and functional capacity of decidual lymphocytes isolated within five hours was comparable to decidual lymphocytes isolated after 24-h preservation in Celsior(®) or PBS. Minor differences were found between decidual lymphocytes isolated within five hours and decidual lymphocytes isolated after 24-h preservation in Celsior(®). The results indicate that PBS is sufficient to preserve the placenta for 24h for phenotypical and functional studies. The ability to preserve the placenta will simplify the procedure for the isolation of decidual lymphocytes and makes it easier to analyze tissue from women who deliver during the night, at weekends or in other hospitals, and possibly even women with complicated pregnancies.

Xeroprotectants for the stabilization of biomaterials

With the advancement of science and technology, it is crucial to have effective preservation methods for the stable long-term storage of biological material (biomaterials). As an alternative to cryopreservation, various techniques have been developed, which are based on the survival mechanism of anhydrobiotic organisms. In this sense, it has been found that the synthesis of xeroprotectants can effectively stabilize biomaterials in a dry state. The most widely studied xeroprotectant is trehalose, which has excellent properties for the stabilization of certain proteins, bacteria, and biological membranes. There have also been attempts to apply trehalose to the stabilization of eukaryotic cells but without conclusive results. Consequently, a xeroprotectant or method that is useful for the stable drying of a particular biomaterial might not necessarily be suitable for another one. This article provides an overview of recent advances in the use of new techniques to stabilize biomaterials and compare xeroprotectants with other more standard methods.

Comparative impact on islet isolation and transplant outcome of the preservation solutions Institut Georges Lopez-1, University of Wisconsin, and Celsior

BACKGROUND

Institut Georges Lopez-1 (IGL-1) is a preservation solution similar to University of Wisconsin (UW) with reversed Na/K contents. In this study, we assessed the impact of IGL-1, UW, and Celsior (CS) solutions on islet isolation and transplant outcome.

METHODS

We retrospectively analyzed 376 islet isolations from pancreases flushed and transported with IGL-1 (n=95), UW (n=204), or CS (n=77). We determined isolation outcome and β-cell function in vitro. Transplanted patients were divided into three groups depending on preservation solution of pancreas, and islet graft function was assessed by decrease in daily insulin needs, C-peptide/glucose ratios, β-scores, and transplant estimated function at 1- and 6-month follow-up.

RESULTS

IGL-1, UW, and CS groups were similar according to donor age, body mass index, and pancreas weight. There was no difference in islet yields between the three groups. Success rates, transplant rates, β-cell secretory function, and viability were similar for all three groups. We observed no difference in decreased insulin needs, C-peptide glucose ratios, β-scores, and transplant estimated function at 1- and 6-month follow-up between IGL-1, UW, and CS groups.

CONCLUSIONS

Our study shows that IGL-1 is equivalent to UW or CS solutions for pancreas perfusion and cold storage before islet isolation and transplantation.

Implication of mitochondrial cytoprotection in human islet isolation and transplantation

Islet transplantation is a promising therapy for type 1 diabetes mellitus; however, success rates in achieving both short- and long-term insulin independence are not consistent, due in part to inconsistent islet quality and quantity caused by the complex nature and multistep process of islet isolation and transplantation. Since the introduction of the Edmonton Protocol in 2000, more attention has been placed on preserving mitochondrial function as increasing evidences suggest that impaired mitochondrial integrity can adversely affect clinical outcomes. Some recent studies have demonstrated that it is possible to achieve islet cytoprotection by maintaining mitochondrial function and subsequently to improve islet transplantation outcomes. However, the benefits of mitoprotection in many cases are controversial and the underlying mechanisms are unclear. This article summarizes the recent progress associated with mitochondrial cytoprotection in each step of the islet isolation and transplantation process, as well as islet potency and viability assays based on the measurement of mitochondrial integrity. In addition, we briefly discuss immunosuppression side effects on islet graft function and how transplant site selection affects islet engraftment and clinical outcomes.

Concentration and chain length of polyethylene glycol in islet isolation solution: evaluation in a pancreatic islet transplantation model

To improve graft preservation and consequently reduce conservation injuries, the composition of preservation solution is of outmost importance. It was demonstrated that the colloid polyethylene glycol (PEG), used in SCOT solution, has protective effects on cell membranes and immunocamouflage properties. The aim of this study was to optimize the concentration and chain length of PEG to improve pancreatic islet preservation and outcome. In a model of murine islet allotransplantation, islets were isolated with SCOT containing various concentrations of PEG 20 kDa or 35 kDa. Better islet yield (IEQ) was obtained with SCO +PEG at 15-30 g/L versus other PEG concentrations and control CMRL-1066 + 1% BSA solution (p < 0.05). Allograft survival was better prolonged (up to 20 days) in the groups SCOT + PEG 20 kDa 10-30 g/L compared to PEG 35 kDa (less than 17.8 days) and to control solutions (less than 17.5 days). In terms of graft function recovery, the use of PEG 20 kDa 15-30 g/L induced no primary nonfunction and delayed graft function contrary to CMRL-1066 and other PEG solutions. The use of the extracellular-type solution SCOT containing PEG 20 kDa 15 g/L as colloid could be a new way to optimize graft integrity preservation and allograft outcome.

Protective effects of hypothermic ex vivo perfusion on ischemia/reperfusion injury and transplant outcomes

Hypothermic machine preservation (HMP) has been used in renal transplantation since the late 1960s with recent robust prospective, multicenter data showing lower rates of delayed graft function and improved graft survival. Although now clearly beneficial for renal transplantation, extrarenal machine perfusion has remained predominantly in preclinical investigations. Pancreatic HMP has drawn little clinical interest because HMP has been suggested to cause graft edema and congestion, which is associated with early venous thrombosis and graft failure. Early investigation showed no benefit of HMP in whole-organ pancreas transplant. One report did show that HMP increases islet cell yield after isolation. Preclinical work in liver HMP has been promising. Short- and long-term HMP has been shown to improve graft viability and reduce preservation injury, even in animal models of steatotic and donation after cardiac death. The first clinical study of liver HMP using a centrifugal dual perfusion technique showed excellent results with lower hepatocellular injury markers and no adverse perfusion-related outcomes. In addition, a dramatic attenuation of proinflammatory cytokine expression was observed. Further studies of liver HMP are planned with focus on developing a reproducible and standard protocol that will allow the widespread availability of this technology. Future research and clinical trials of novel organ preservation techniques, solutions, and interventions are likely to bring about developments that will allow further reduction of preservation-related ischemia/reperfusion injury and improved outcomes and allow safer utilization of the precious and limited resource of donor organs.

Islet transplantation: factors in short-term islet survival

Islet transplantation has the potential to cure type 1 diabetes. In recent years, the proportion of patients achieving initial insulin independence has improved, but longer term outcomes remain poor compared to those for whole pancreas transplants. This review article will discuss factors affecting islet yield and viability leading up to transplantation and in the immediate post-transplant period.

Assessment of beta cell viability

This unit contains detailed protocols for the simultaneous identification of the human pancreatic β cells and determination of their viability by flow cytometry. The enumeration of β cells is based on the ability of the cell-permeable form of the zinc-selective dye, FluoZin-3-AM, to bind intracellular labile zinc stored at higher levels in these cells than any other types of cells in the body. Although staining of intracellular labile zinc by FluoZin-3-AM is dependent on the metabolic activity of β cells, co-staining with a mitochondrial transmembrane potential indicator allows the accurate determination of viability. Simultaneous measurement of intracellular antioxidant thiols is also compatible with the detection of β cells containing metabolically active mitochondria. The method for assessing the mitochondrial functionality by flow cytometry described herein is simple to perform and sufficient to detect the viability of β cells in human islet preparations.

Organ Preservation: Current Concepts and New Strategies for the Next Decade

SUMMARY: Organ transplantation has developed over the past 50 years to reach the sophisticated and integrated clinical service of today through several advances in science. One of the most important of these has been the ability to apply organ preservation protocols to deliver donor organs of high quality, via a network of organ exchange to match the most suitable recipient patient to the best available organ, capable of rapid resumption of life-sustaining function in the recipient patient. This has only been possible by amassing a good understanding of the potential effects of hypoxic injury on donated organs, and how to prevent these by applying organ preservation. This review sets out the history of organ preservation, how applications of hypothermia have become central to the process, and what the current status is for the range of solid organs commonly transplanted. The science of organ preservation is constantly being updated with new knowledge and ideas, and the review also discusses what innovations are coming close to clinical reality to meet the growing demands for high quality organs in transplantation over the next few years.

The pancreas allograft donor: current status, controversies, and challenges for the future

The pancreas allograft is a scarce resource that is currently underutilized. The selection of appropriate deceased donors for pancreas procurement is of paramount importance for minimizing technical failure and optimizing long-term outcomes in pancreas transplantation. Despite the increasing demand for pancreas transplantation, increases in overall organ donation rates and the evolution of criteria that constitute an "acceptable" pancreas donor, the number of deceased donor pancreas transplants being performed in the United States has actually declined in recent years. Although there are many factors that must be considered during evaluation of the potential pancreas allograft donor to minimize morbidity and graft loss, it is evident that there are transplantable organs that are not used. In this review, deceased donor pancreas identification, management, selection, allocation, assessment, preservation, and the problem of pancreas underutilization will be discussed.

Immune monitoring of pancreatic islet graft: towards a better understanding, detection and treatment of harmful events

IMPORTANCE OF THE FIELD

Long-term clinical outcomes of islet transplantation are hampered by rejection and recurrence of autoimmunity, which lead to a gradual decrease in islet function usually taking place over the first five years after transplantation. An accurate monitoring strategy could allow for the detection and treatment of harmful immune events, potentially resulting in higher rates of insulin-independence.

AREAS COVERED IN THIS REVIEW

This article provides a critical review of the various assays currently available for the assessment of allo- and autoimmunity both prior to and after islet transplantation. The accuracy in predicting clinical outcome is specifically addressed.

WHAT THE READER WILL GAIN

Most current tests based on the assessment of allo- and auto-immune antibody are of minimal help in clinical practice. Cell-based tests (including the assessment of cytotoxic T lymphocyte precursors, proliferation tests, enzyme-linked immunospot) have the potential to allow earlier and more accurate detection of harmful events.

TAKE HOME MESSAGE

A specific and accurate immune monitoring has the potential to significantly improve islet transplant outcomes. The development and use of such tests (favouring cell-based tests) should be promoted.

Influence of donor- and recipient-specific factors on the postoperative course after combined pancreas-kidney transplantation

INTRODUCTION

Simultaneous pancreas-kidney (SPK) transplantation is state-of-the-art therapy for patients with type-1 diabetes mellitus and end-stage renal failure. Improvement of long-term organ function and long-term survival after transplantation is the main focus of current research, but improvement of the early postoperative course is very important for the patient. Pancreas transplantation is associated with postoperative complications. We defined and identified donor- and recipient-specific factors related to postoperative complications.

PATIENTS AND METHODS

We carried out 210 SPKs from April 1995 to December 2007. The early postoperative course until first discharge from hospital was analyzed. Complications (pancreas-specific and surgical) were revisited. Donor-specific factors such as sex, age, body mass index (BMI), laboratory values, catecholamine administration, time in the intensive care unit, preprocurement blood substitution, and asystolic periods, as well as factors related to the organ donation procedure, were assessed. Recipient-specific factors such as age, sex, BMI, and blood group were correlated with the prevalence of complications and postoperative outcome. Donor-specific risk factors correlating with postoperative complications included donor age, BMI, and blood transfusion in the donor before organ donation.

RESULTS

Graft preservation with histidine-tryptophan-ketoglutarate perfusion solution was related to a significantly higher number of surgical complications.When analyzing recipient-specific factors, pre-existing cardiac diseases influenced the prevalence of postoperative complications. The duration of the transplantation procedure was associated with significantly more complications. The anastomosis time was not significantly related to an increased prevalence of complications. The choice of immunosuppression had a significant effect on pancreas-specific complications, demonstrating that antithymocyte globulin instead of daclizumab had a negative effect. Initial immunosuppression with tacrolimus combined with mycophenolate mofetil (MMF) caused significantly fewer pancreas-related complications in comparison with tacrolimus combined with rapamycin as well as compared with cyclosporine combined with MMF. A high level of C-reactive protein within the first 7 days after transplantation was significantly related to an increased prevalence of complications.

CONCLUSIONS

Early postoperative complications after combined pancreas-kidney transplantation have a considerable effect on short- and long-term outcomes. Several statistically relevant factors related to pancreas- or surgery-associated complications could be identified. These data may help to improve early outcome after SPK by consideration of relevant risk factors when choosing an organ and a recipient for transplantation.

Quality control for clinical islet transplantation: organ procurement and preservation, the islet processing facility, isolation, and potency tests

Pancreatic islet transplantation has become one of the ideal treatments for patients with type 1 diabetes mellitus due to improvements in isolation techniques and immunosuppression regimens. In order to ensure the safety and rights of patients, isolated islets need to meet the criteria for regulation as both a biological product and a drug product. For the constant success of transplantation, therefore, all investigators involved in clinical islet transplantation must strive to ensure the safety, purity, and potency of islets in all the phases of clinical islet isolation and transplantation. In this review, we summarize the quality control for clinical islet isolation and transplantation, and the latest topics of pre-transplant islet assessment.