Outcomes for circulatory death and brainstem death pancreas transplantation with or without use of normothermic regional perfusion

New methods for improving pancreas preservation

PURPOSE OF REVIEW

Pancreas and islet transplantation face critical organ shortage challenges, with many potential grafts discarded due to concerns about consequences of ischemia-reperfusion injury, particularly from donation after circulatory death (DCD) donors. Static cold storage remains standard practice but has significant limitations. Novel preservation technologies may improve transplant outcomes, donor selection and even expand the donor pool.

RECENT FINDINGS

Normothermic regional perfusion in DCD donors has increased pancreas utilization with promising one-year graft survival comparable to donation after brain-death (DBD) donors. Hypothermic machine perfusion maintains tissue integrity and shows promising preclinical results. Oxygenated hypothermic machine perfusion successfully restores tissue adenosine triphosphate (ATP) levels without notable tissue injury. Normothermic machine perfusion, despite challenges, offers potential for viability assessment and resuscitation.

SUMMARY

Advanced preservation technologies provide platforms for assessment, reconditioning, and therapeutic interventions for pancreas grafts. Clinical translation requires consensus on perfusion parameters and perfusate composition optimized for pancreatic preservation. Future developments should focus on implementing sensitive and specific assessment methods, including beta-cell specific biomarkers, to confidently select and utilize marginal pancreas grafts for transplantation.

Normothermic Regional Perfusion in Controlled Donation After the Circulatory Determination of Death: Understanding Where the Benefit Lies

Controlled donation after the circulatory determination of death (cDCDD) has emerged as a strategy to increase the availability of organs for clinical use. Traditionally, organs from cDCDD donors have been subject to standard rapid recovery (SRR) with poor posttransplant outcomes of abdominal organs, particularly the liver, and limited organ utilization. Normothermic regional perfusion (NRP), based on the use of extracorporeal membrane oxygenation devices, consists of the in situ perfusion of organs that will be subject to transplantation with oxygenated blood under normothermic conditions after the declaration of death and before organ recovery. NRP is a potential solution to address the limitations of traditional recovery methods. It has become normal practice in several European countries and has been recently introduced in the United States. The increased use of NRP in cDCDD has occurred as a result of a growing body of evidence on its association with improved posttransplant outcomes and organ utilization compared with SRR. However, the expansion of NRP is precluded by obstacles of an organizational, legal, and ethical nature. This article details the technique of both abdominal and thoracoabdominal NRP. Based on the available evidence, it describes its benefits in terms of posttransplant outcomes of abdominal and thoracic organs and organ utilization. It addresses cost-effectiveness aspects of NRP, as well as logistical and ethical obstacles that limit the implementation of this innovative preservation strategy.

Donor after circulatory death in pancreas transplantation: a scoping review of the literature

The growing disparity between the demand for pancreas transplants and the availability of suitable organs underscores the urgent need for innovative donor strategies, including the utilization of donors after circulatory death (DCD). This scoping review presents a comprehensive comparative analysis of transplantation outcomes between DCD and donors after brain death (DBD), focusing on pancreatic graft survival, postoperative complications, and functional metrics such as graft performance and HbA1c levels. Although DCD grafts were suspected to be associated with higher rates of early complications, including delayed graft function and thrombosis, altogether resulting from potentially more ischemia-reperfusion injuries, their long-term outcomes are comparable to those of DBD grafts. This equivalence is likely driven by careful donor selection, a meticulous pancreas procurement, use of normothermic regional perfusion and a short ischemic time. The findings highlight the transformative potential of DCD donors in expanding the pancreas donor pool, addressing critical organ shortages, and enhancing transplant accessibility. This review advocates for the integration of DCD donors into routine clinical practice, emphasizing the need for optimized clinical protocols and organ allocation strategies. By leveraging DCD donors more effectively, the transplant community can make significant strides in improving patient outcomes and addressing the global organ shortage crisis.

The impact of time to death in donors after circulatory death on recipient outcome in simultaneous pancreas-kidney transplantation

The time to arrest donors after circulatory death is unpredictable and can vary. This leads to variable periods of warm ischemic damage prior to pancreas transplantation. There is little evidence supporting procurement team stand-down times based on donor time to death (TTD). We examined what impact TTD had on pancreas graft outcomes following donors after circulatory death (DCD) simultaneous pancreas-kidney transplantation. Data were extracted from the UK transplant registry from 2014 to 2022. Predictors of graft loss were evaluated using a Cox proportional hazards model. Adjusted restricted cubic spline models were generated to further delineate the relationship between TTD and outcome. Three-hundred-and-seventy-five DCD simultaneous kidney-pancreas transplant recipients were included. Increasing TTD was not associated with graft survival (adjusted hazard ratio HR 0.98, 95% confidence interval 0.68-1.41, P = .901). Increasing asystolic time worsened graft survival (adjusted hazard ratio 2.51, 95% confidence interval 1.16-5.43, P = .020). Restricted cubic spline modeling revealed a nonlinear relationship between asystolic time and graft survival and no relationship between TTD and graft survival. We found no evidence that TTD impacts pancreas graft survival after DCD simultaneous pancreas-kidney transplantation; however, increasing asystolic time was a significant predictor of graft loss. Procurement teams should attempt to minimize asystolic time to optimize pancreas graft survival rather than focus on the duration of TTD.

Simultaneous Pancreas and Kidney Transplantation from Donors after Circulatory Death in Switzerland

Background: Simultaneous pancreas and kidney transplantation (SPK) remains the only curative treatment for type I diabetics with end-stage kidney disease. SPK using donors after circulatory death (DCD) is one important measure to expand the organ pool for pancreas transplantation (PT). After initial doubts due to higher complications, DCD SPK is now considered safe and equivalent to donation after brain death in terms of survival and graft function. Materials and Methods: We assessed pancreas and kidney graft function, as well as complications of the first three patients who underwent a DCD SPK in Switzerland. Two transplantations were after rapid procurement, one following normothermic regional perfusion (NRP). Results: Intra- and postoperative courses were uneventful and without major complications in all patients. In the two SPK after rapid procurement, pancreas graft function was excellent, with 100% insulin-free survival, and hemoglobin A1C dropped from 7.9 and 7.5 before SPK and to 5.1 and 4.3 after three years, respectively. Kidney graft function was excellent in the first year, followed by a gradual decline due to recurrent infections. The patient, after NRP SPK, experienced short-term delayed pancreatic graft function requiring low-dose insulin treatment for 5 days post-transplant, most likely due to increased peripheral insulin resistance in obesity. During follow-up, there was persistent euglycemia and excellent kidney function. Conclusions: We report on the first series of DCD SPK ever performed in Switzerland. Results were promising, with low complication rates and sustained graft survival. With almost half of all donors in Switzerland currently being DCD, we see great potential for the expansion of DCD PT.

British Transplantation Society guidelines on abdominal organ transplantation from deceased donors after circulatory death

The British Transplantation Society (BTS) 'Guideline on transplantation from deceased donors after circulatory death' has recently been updated and this manuscript summarises the relevant recommendations in abdominal organ transplantation from Donation after Circulatory Death (DCD) donors, encompassing the chapters on liver, kidney, pancreas and islet cell transplantation.

Poor utilization of deceased donor pancreata in the United States: Time for action

The number of solid organ pancreas transplants performed in the United States has declined over the past two decades despite improving outcomes and the known benefits associated with this procedure. Although the reasons are multifactorial, high rates of deceased donor pancreata nonrecovery and nonuse have at least in part contributed to the reduction in pancreas transplant activity. The pancreas has higher nonrecovery and nonuse rates compared to the kidney and liver because of more stringent donor selection criteria, particularly with respect to donor age and body mass index, although even marginally inferior donor pancreata likely still benefit some patients compared to alternative therapies. In this editorial, we present several donor-, candidate-, and center-specific factors that are either confirmed or suspected of being associated with inferior outcomes, which contribute to high pancreas nonrecovery and nonuse rates. In addition, we have discussed several measures to increase pancreas recovery and reduce pancreas nonutilization.

Normothermic Regional Perfusion in Controlled Donation After Circulatory Determination of Death Simultaneous Pancreas - Kidney Transplantation

BACKGROUND

Simultaneous pancreas-kidney transplantation is the optimal treatment for patients with type 1 diabetes and renal failure. The use of pancreas grafts from donation after circulatory death (DCD), using normothermic regional perfusion (NRP), is still marginal worldwide, mainly due to possible additional risks of graft dysfunction and complications compared with grafts from donors after brain death.

METHODS

Case series of patients who underwent simultaneous pancreas-kidney transplantation after DCD-NRP between January 2018 and September 2022. This study evaluated early postoperative grafts and survival outcomes.

RESULTS

Four patients were included. One patient lost the pancreatic graft due to arterial thrombosis requiring transplantectomy. Another patient required a laparotomy due to hemoperitoneum. Overall, 1-year pancreas and kidney graft survival was 75% and 100%, respectively. One patient developed a lymphoma during the follow-up.

CONCLUSION

The use of pancreas grafts from DCD after NRP preservation is safe and feasible. Comparative studies with donors after brain death grafts and larger series are required to confirm the feasibility of DCD-NRP pancreas transplantation.

Outcomes of livers from donation after circulatory death donors with extended agonal phase and the adjunct of normothermic regional perfusion

The liver performs important functions that are essential for life. If the liver fails, patients will die unless they receive a new liver from a donor (transplant). Unfortunately, there are not enough livers for everyone and some patients die while waiting for a suitable organ. This article describes a novel technique that allows resuscitation and testing of a potential donor liver so that more patients can safely receive a transplant.

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.

From Haphazard to a Sustainable Normothermic Regional Perfusion Service: A Blueprint for the Introduction of Novel Perfusion Technologies

Normothermic Regional Perfusion (NRP) has shown encouraging clinical results. However, translation from an experimental to routine procedure poses several challenges. Herein we describe a model that led to the implementation of NRP into standard clinical practice in our centre following an iterative process of refinement incorporating training, staffing and operative techniques. Using this approach we achieved a four-fold increase in trained surgical staff and a 6-fold increase in competent senior organ preservation practitioners in 12 months, covering 93% of the retrieval calls. We now routinely provide NRP throughout the UK and attended 186 NRP retrievals from which 225 kidneys, 26 pancreases and 61 livers have been transplanted, including 5 that were initially declined by all UK transplant centres. The 61 DCD(NRP) liver transplants undertaken exhibited no primary non-function or ischaemic cholangiopathy with up to 8 years of follow-up. This approach also enabled successful implementation of ex situ normothermic liver perfusion which together with NRP contributed 37.5% of liver transplant activity in 2021. Perfusion technologies (in situ and ex situ) are now supported by a team of Advanced Perfusion and Organ Preservation Specialists. The introduction of novel perfusion technologies into routine clinical practice presents significant challenges but can be greatly facilitated by developing a specific role of Advanced Perfusion and Organ Preservation Specialist supported by a robust education, training and recruitment programme.