Outcome of pancreas transplantation from donation after circulatory death compared to donation after brain death

Sterile Pancreas Inflammation during Preservation and after Transplantation

The pancreas is very susceptible to ischemia-reperfusion injury. Early graft losses due to pancreatitis and thrombosis represent a major issue after pancreas transplantation. Sterile inflammation during organ procurement (during brain death and ischemia-reperfusion) and after transplantation affects organ outcomes. Sterile inflammation of the pancreas linked to ischemia-reperfusion injury involves the activation of innate immune cell subsets such as macrophages and neutrophils, following tissue damage and release of damage-associated molecular patterns and pro-inflammatory cytokines. Macrophages and neutrophils favor tissue invasion by other immune cells, have deleterious effects or functions, and promote tissue fibrosis. However, some innate cell subsets may promote tissue repair. This outburst of sterile inflammation promotes adaptive immunity activation via antigen exposure and activation of antigen-presenting cells. Better controlling sterile inflammation during pancreas preservation and after transplantation is of utmost interest in order to decrease early allograft loss (in particular thrombosis) and increase long-term allograft survival. In this regard, perfusion techniques that are currently being implemented represent a promising tool to decrease global inflammation and modulate the immune response.

Novel Organ Perfusion and Preservation Strategies in Controlled Donation After Circulatory Death in Pancreas and Kidney Transplantation

BACKGROUND

Kidney and pancreatic transplants from controlled donation after circulatory death donors are vulnerable to ischemia-reperfusion injuries. In this context of transplant shortage, there is a need to optimize the function of these transplants and to develop novel perfusion and preservation strategies in controlled donation after circulatory death in kidney and pancreatic transplants.

IN SITU PERFUSION AND PRESERVATION STRATEGIES

In situ regional normothermic perfusion improves the outcome of kidney transplants from controlled donation after circulatory death and provides equivalent results for the kidney from brain-dead donors. In situ regional normothermic perfusion is under investigation for pancreatic transplants.

EX SITU PERFUSION AND PRESERVATION STRATEGIES

Perfusion on hypothermic machine perfusion is highly recommended for the kidney from controlled donation after cardiac death. Hypothermic oxygenated perfusion machine decreases the rate of graft rejection and graft failure in kidney transplantation. Ex situ normothermic perfusion is an easy way to assess renal function. In the future, kidney transplants could benefit from drug therapy during ex situ normothermic perfusion. In pancreas transplantation, hypothermic machine perfusion and ex situ normothermic perfusion present encouraging results in preclinical studies.

Outcomes after simultaneous pancreas-kidney transplantation from donation after circulatory death donors: A UK registry analysis

There are concerns that simultaneous pancreas-kidney (SPK) transplants from donation after circulatory death (DCD) donors have a higher risk of graft failure than those from donation after brain death (DBD) donors. A UK registry analysis of SPK transplants between 2005 and 2018 was performed. Pancreas survivals of those receiving organs from DCD or DBD donors were compared. Multivariable analyses were used to adjust for baseline differences between the two groups and to identify factors associated with pancreas graft loss. A total of 2228 SPK transplants were implanted; 403 (18.1%) were from DCD donors. DCD donors were generally younger, slimmer, less likely to have stroke as a cause of death, with lower terminal creatinines and shorter pancreas cold ischemic times than DBD donors. Median (IQR) follow-up was 4.2 (1.6-8.1) years. On univariable analysis, there were no statistically significant differences in 5-year death-censored pancreas graft survival between the two donor types (79.5% versus 80.4%; p = .86). Multivariable analysis showed no statistically significant differences in 5-year pancreas graft loss between transplants from DCD (n = 343) and DBD (n = 1492) donors (hazard ratio 1.26, 95% CI 0.76-1.23; p = .12). The findings from this study support the increased use of SPK transplants from DCD donors.

Clinical use of donation after circulatory death pancreas for islet transplantation

Due to a shortage of donation after brain death (DBD) organs, donation after circulatory death (DCD) is increasingly performed. In the field of islet transplantation, there is uncertainty regarding the suitability of DCD pancreas in terms of islet yield and function after islet isolation. The aim of this study was to investigate the potential use of DCD pancreas for islet transplantation. Islet isolation procedures from 126 category 3 DCD and 258 DBD pancreas were performed in a 9-year period. Islet yield after isolation was significantly lower for DCD compared to DBD pancreas (395 515 islet equivalents [IEQ] and 480 017 IEQ, respectively; p = .003). The decrease in IEQ during 2 days of culture was not different between the two groups. Warm ischemia time was not related to DCD islet yield. In vitro insulin secretion after a glucose challenge was similar between DCD and DBD islets. After islet transplantation, DCD islet graft recipients had similar graft function (AUC C-peptide) during mixed meal tolerance tests and Igls score compared to DBD graft recipients. In conclusion, DCD islets can be considered for clinical islet transplantation.

Outcomes From Brain Death Donors With Previous Cardiac Arrest Accepted for Pancreas Transplantation: A Single-center Retrospective Analysis

OBJECTIVE

The aim of the study was to evaluate the effect of cardiac arrest time (CAT) in donors after brain death (DBD) donors on pancreas transplant outcome.

SUMMARY OF BACKGROUND DATA

Results from donors after circulatory death report good outcomes despite warm ischemia times up to 57 minutes. Previous cardiac arrest in DBD has been addressed as a potential risk factor, but duration of the CAT has never been evaluated.

METHODS

We conducted a retrospective analysis including 342 pancreas transplants performed at our center from 2000 to 2016, and evaluated the effect of previous cardiac arrest in DBD (caDBD) on pancreas transplant outcomes.

RESULTS

A total of 49 (14.3%) caDBD were accepted for transplantation [median CAT of 5.0 min (IQR 2.5-15.0)]. Anoxic encephalopathy was most frequent and P-PASS higher (16.9 vs 15.6) in caDBD group when compared with other DBD. No differences were found in all other characteristics evaluated.Graft survival was similar between both groups, as was the incidence of early graft failure (EGF). CAT increased the risk for EGF [OR 1.09 (95% CI, 1.01-1.17)], and the duration of CPR discriminated for EGF [AUC of 0.86 (95% CI, 0.74-0.98)], with a sensitivity and specificity of 100% and 75% at a cutoff of 15 minutes. When evaluated separately, caDBD >15 min increased over 5 times the risk for EGF [HR 5.80 (95% CI, 1.82-18.56); P = 0.003], and these presented fewer days on the ICU (1.0 vs 3.0 d).

CONCLUSION

CaDBD donors are suitable for routine pancreas transplantation without increasing EGF risk, and in those with longer CAT it may be prudent to postpone donation a few days to allow a thorough evaluation of organ damage following cardiac arrest.

Trauma and donation after circulatory death: a case series from a major trauma center

Even with encouraging recipient outcomes, transplantation using donation after circulatory death (DCD) is still limited. A major barrier to this type of transplantation is the consequences of warm ischemia on graft survival; however, preservation techniques may reduce the consequences of cardiac arrest and provide better organ conservation. Furthermore, DCD in trauma patients could further expand organ donation. We present five cases in which organs were retrieved and transplanted successfully using normothermic regional perfusion (NRP) in trauma patients. Prompt critical care support and surgical treatment allowed us to overcome the acute phase. Unfortunately, owing to the severity of their injuries, all of the donors died. However, the advanced and continuous organ-specific supportive treatment allowed the maintenance of general clinical stability and organ preservation. Consequently, it was possible to retrieve and transplant the donors’ organs. Death was ascertained in accordance with cardio-circulatory criteria, which was followed by NRP. We consider that DCD in trauma patients may represent an important source of organs.

Challenges of pancreas transplantation in developing countries, exploring the Turkey example

Pancreas transplantation significantly improves the quality of life for people with type 1 diabetes, primarily by eliminating the need for insulin and frequent blood glucose measurements. Despite the growing numbers of solid organ transplantations worldwide, number of pancreas transplantations in the developing countries` remain significantly low. This difference of pancreas transplantation practices was striking among the participating countries at the 1st International Transplant Network Meeting which was held in Turkey on 2018. In this meeting more than 40 countries were represented. Most of these counties were developing countries located in Africa, Middle East or Asia. The aim of this article is to identify the challenges and limiting factors for pancreas transplantations in these developing countries, by exploring the Turkish example. The challenges faced by the developing countries are broadly classified in four categories; wait-listing, donor pool, team work and follow up. Under these categorical titles, issues are further discussed in detail, giving examples from Turkish practice of pancreas transplantation. Additionally, several solutions to these challenges have been proposed- some of which have already been undertaken by the Turkish Ministry of Health. With the insight and methods presented in this article, pancreas transplantation should be made possible for the potential recipients in the developing countries.

Pancreas Transplantation from Donors after Circulatory Death: an Irrational Reluctance?

PURPOSE OF REVIEW

Beta-cell replacement is the best therapeutic option for patients with type 1 diabetes. Because of donor scarcity, more extended criteria donors are used for transplantation. Donation after circulatory death donors (DCD) are not commonly used for pancreas transplantation, because of the supposed higher risk of complications. This review gives an overview on the pathophysiology, risk factors, and outcome in DCD transplantation and discusses different preservation methods.

RECENT FINDINGS

Studies on outcomes of DCD pancreata show similar results compared with those of donation after brain death (DBD), when accumulation of other risk factors is avoided. Hypothermic machine perfusion is shown to be a safe method to improve graft viability in experimental settings. DCD should not be the sole reason to decline a pancreas for transplantation. Adequate donor selection and improved preservation techniques can lead to enhanced pancreas utilization and outcome.

Risk analysis of extended pancreas donor selection criteria

INTRODUCTION

The success of pancreas transplantation, in combination with a stable number of available allografts has resulted in an increasing waiting list. This study investigated donor potential by expanding age and Body Mass Index (BMI) criteria.

METHODS

All reported donors in the Netherlands between 2013 and 2017 were analysed. Risk assessment of extended criteria donors was done by in-depth analysis of donor reports and calculation of the Pancreas Donor Risk Index (PDRI). The PDRI of these extended criteria donors was compared to standard criteria donors to evaluate the increased risk on graft failure.

RESULTS

A total of 1273 donors were reported. Of these donors, 405 donors were reported as pancreas donor, of which 93 (23%) pancreata were transplanted. Extending age criterion with 5 years could result in additional 40 Donation after Brain Death donors and 37 Donation after Circulatory Death donors reported. In 24 (31%) extended age criteria donors the PDRI was below the upper limit of currently transplanted pancreata. Extending BMI criteria to 35 kg/m² could result in an additional 19 (6%) donors reported.

CONCLUSIONS

Extending BMI criteria could result in a slight increase of reported donors. Extending age criteria increased significantly the number of reported donors. In 24 (31%) of the older donors the PDRI showed a reduced risk compared to currently transplanted pancreata. This study suggest that, if other risk factors are absent, pancreata of extended age and/or BMI criteria donors should be considered for transplantation.

Machine Perfusion and the Pancreas: Will It Increase the Donor Pool?

PURPOSE OF REVIEW

Pancreas transplantation enables complete patient independence from exogenous insulin administration and increases both patient survival and quality of life. Despite this, there has been a decline in pancreas transplantation for the past 20 years, influenced by changing donor demographics with more high-risk extended criteria (ECD) and donation after cardiac death (DCD) donors. This review discusses whether the advent of machine perfusion (MP), if extended to the pancreas, can increase the pool of suitable donor organs.

RECENT FINDINGS

Hypothermic and normothermic MP, as forms of preservation deemed superior to cold storage for high-risk kidney and liver donor organs, have opened the avenue for translation of this work into the pancreas. Recent experimental models of porcine and human ex-vivo pancreatic MP are promising. Applications of MP to the pancreas however need refinement-focusing on perfusion protocols and viability assessment tools. Emerging research shows pancreatic MP can potentially offer superior preservation capacity, the ability to both resuscitate and manipulate organs, and assess functional and metabolic organ viability. The future of MP will lie in organ assessment and resuscitation after retrieval, where ultimately organs initially considered high risk and unsuitable for transplantation will be optimised and transformed, making them then available for clinical use, thus increasing the pool of suitably viable pancreata for transplantation.

Maximizing Utilization in Pancreas Transplantation: Phenotypic Characteristics Differentiating Aggressive From Nonaggressive Transplant Centers

BACKGROUND

Maximizing pancreas utilization requires a balance between judicious donor selection and transplant center aggressiveness. We sought to determine how such aggressiveness affects transplant outcomes.

METHODS

Using the Scientific Registry of Transplant Recipients, we studied 28 487 deceased-donor adult pancreas transplants. Donor and recipient demographic factors indicative of aggressiveness were used to score center aggressiveness. We compared outcomes of low (> 1 SD below mean), medium (± 1 SD from mean), and high (> 1 SD above mean) aggressiveness centers using bivariate and multivariable regressions.

RESULTS

Donor and recipient aggressiveness demonstrated a roughly linear relationship (R = 0.20). Center volume correlated moderately with donor (rs = 0.433) and recipient (rs = 0.270) aggressiveness. In bivariate analysis, there was little impact of donor selection aggressiveness on graft survival. Further, for simultaneous pancreas and kidney transplants, centers with greater recipient aggressiveness selection had better graft survival. High-volume centers had better graft survival than low-volume centers. In multivariable analysis, donor aggressiveness did not have an effect on graft survival, whereas graft survival for medium (hazard ratio [HR], 0.66, 95% confidence interval [95% CI], 0.53-0.83) and high (HR, 0.67; CI, 0.51-0.86) recipient aggressiveness performed better than low-aggressiveness centers. There was a clear volume effect, with high-volume centers (>20 transplants/year; HR, 0.69; CI, 0.61-0.79) performing better than low-volume centers.

CONCLUSIONS

Center practice patterns using higher-risk donors and recipients did not negatively affect outcomes. This effect is likely mediated through efficiencies gained with the increased transplant volumes at these centers.

A steady decline in pancreas transplantation rates

BACKGROUND/OBJECTIVES

After years of growth in many pancreas transplant programs, UNOS has reported declining transplant numbers in the USA. This precipitating trend urges for an evaluation of the transplant numbers and scientific productivity in the Eurotransplant region and the UK.

METHODS

We performed a trend analysis of pancreas transplantation rates, between 1997 and 2016, adjusting for changes in population size, and an analysis of scientific publications in this field. We used information from the UNOS, Eurotransplant, and UK transplant registry and bibliometric information from the Web of Science database.

RESULTS

Between 2004 and 2016 there was an average annual decline in pancreas transplantation rates per million inhabitants of 3.3% in the USA and 2.5% in the Eurotransplant region. In the UK, transplant numbers showed an average annual decline of 1.0% from 2009 to 2016. Publications in Q1 journals showed an annual change of -2.1% and +20.1%, before 2004, and a change of -3.8% and -5.5%, between 2004 and 2016, for USA and Eurotransplant publications, respectively.

CONCLUSIONS

Adjusting pancreas transplantation rates for changes in population size showed a clear decline in transplant numbers in both the USA and Eurotransplant region, with first signs of decline in the UK. Following this trend, the number of scientific publications in this field have declined worldwide.

Impact of Donor Age on Clinical Outcomes of Primary Single Kidney Transplantation From Maastricht Category-III Donors After Circulatory Death

BACKGROUND

Standard-criteria donation after circulatory death (DCD) kidney transplants (KTx) have higher primary nonfunction, delayed graft function (DGF), and rejection rates than age-matched donation after brain death (DBD) but similar graft survival. Data on expanded-criteria DCD are conflicting and many centers remain concerned regarding their use.

METHODS

In this single-center observational study with 5-year follow-up, we analyzed data from 112 primary DCD Maastricht category-III single KTx receiving similar organ preservation and maintenance immunosuppression. Patients were sorted as young DCD (donor <60 years, 72 recipients) or old DCD (donor ≥60 years, 40 recipients). Old DCD outcomes were compared with young DCD and to a DBD control group (old DBD, donor ≥60 years, 40 recipients).

RESULTS

After 5 years, old DCD showed lower patient survival (66% vs 85%; P = 0.014), death-censored graft survival (63% vs 83%; P = 0.001), and Modification of Diet in Renal Disease estimated glomerular filtration rate (34, 27.0-42.0 mL/min per 1.73 m2 vs 45.0, 33.0-58.0 mL/min per 1.73 m2; P = 0.021) than young DCD with higher DGF (70% vs 47.2%; P = 0.029) and graft thrombosis (12.5% vs 1.4%; P = 0.021). Comparison between old DCD and old DBD showed similar 5-year patient survival (66% vs 67%; P = 0.394) and death-censored graft survival (63% vs 69%; P = 0.518) but higher DGF (70% vs 37.5%; P = 0.007) and lower estimated glomerular filtration rate (34, 27.0-42.0 mL/min per 1.73 m2 vs 41, 40.0-42.0 mL/min per 1.73 m2; P = 0.029). Multivariate Cox regression analysis showed that donor 60 years or older (hazard ratio, 3.135; 95% confidence interval, 1.716-5.729; P < 0.001) and induction with anti-IL2-receptor-α monoclonal antibody (hazard ratio, 0.503; 95% confidence interval, 0.269-0.940, P = 0.031 in favor of induction with rabbit antithymocyte globulin) are independent predictors of transplant loss.

CONCLUSIONS

Overall, single KTx from DCD Maastricht category-III donors 60 years or older have inferior outcomes than KTx from donors younger than 60 years. Comparison with age-matched DBD showed similar patient and graft survivals. However, the discrepancy in graft function between DCD and DBD deserves further investigation.

β Cell Replacement Therapy: The Next 10 Years

β cell replacement with either pancreas or islet transplantation has progressed immensely over the last decades with current 1- and 5-year insulin independence rates of approximately 85% and 50%, respectively. Recent advances are largely attributed to improvements in immunosuppressive regimen, donor selection, and surgical technique. However, both strategies are compromised by a scarce donor source. Xenotransplantation offers a potential solution by providing a theoretically unlimited supply of islets, but clinical application has been limited by concerns for a potent immune response against xenogeneic tissue. β cell clusters derived from embryonic or induced pluripotent stem cells represent another promising unlimited source of insulin producing cells, but clinical application is pending further advances in the function of the β cell like clusters. Exciting developments and rapid progress in all areas of β cell replacement prompted a lively debate by members of the young investigator committee of the International Pancreas and Islet Transplant Association at the 15th International Pancreas and Islet Transplant Association Congress in Melbourne and at the 26th international congress of The Transplant Society in Hong Kong. This international group of young investigators debated which modality of β cell replacement would predominate the landscape in 10 years, and their arguments are summarized here.

Pancreas Transplantation With Grafts From Donors Deceased After Circulatory Death: 5 Years Single-Center Experience

BACKGROUND

Donation after circulatory death (DCD) pancreas transplantation has been shown to be an additional way to deal with donor organ shortages. The results of 5-year DCD pancreas transplantation are presented.

METHODS

A retrospective, single-center analysis (2011-2015) was performed to compare the results of donation after brain death (DBD) to DCD pancreas transplantation.

RESULTS

During the study period, 104 pancreas transplantations (83 from DBD and 21 from DCD) were performed. Median Pancreas Donor Risk Index (PDRI) was 1.47, (DBD, 1.61 vs DCD, 1.35; P = 0.144). Without the factor DCD, PDRI from DCD donors was significantly lower (DBD, 1.61 vs DCD, 0.97; P < 0.001). Donor age was the only donor-related risk factor associated with pancreas graft survival (Hazard ratio, 1.06; P = 0.037). Postoperative bleeding and kidney delayed graft function occurred more frequently in recipients from DCD (P = 0.006). However, DCD pancreata had a lower incidence of thrombosis. Kidney and pancreas graft survival were equally good in both groups.

CONCLUSIONS

Pancreas transplantation from DCD donors yields comparable results to DBD donors when PDRI of DCD is relatively low. Most DCD donors are younger donors with trauma as cause of death. These DCD pancreas grafts may be a better option to cope with increasing organ shortages than exploring the limits with older (and higher PDRI) DBD donors.

Donors after circulatory death pancreas transplantation

PURPOSE OF REVIEW

The use of organs from donors after circulatory death (DCD) has become standard practice in solid organ transplantation of most abdominal organs and has been used successfully in some centres for pancreas transplantation. Nevertheless, concerns regarding poor graft outcomes and complications remain. This review aims to discuss the current state of DCD pancreas transplantation and the associated outcomes.

RECENT FINDINGS

In many countries, whereas the number of donors after brainstem death (DBD) remains stable, the mean age and BMI have increased making these donors, previously considered to be low risk, now more marginal. Recent meta-analyses have confirmed previous single-centre and registry reports that graft and patient survival after DCD pancreas transplantation are comparable with outcomes using pancreases from DBD donors; DCD pancreas transplantation is now common practice in several countries in Europe, particularly the United Kingdom. Although there have been reports of higher thrombosis rates after DCD pancreas transplantation, the significance of this is difficult to judge as the impact has not been seen in overall graft survival.

SUMMARY

Pancreas transplantation using DCD organs is well tolerated and feasible when other risk factors are minimized. Although there has been some evidence of an increased risk of thrombosis, this has not translated into a significant difference in graft survival.