A steady decline in pancreas transplantation rates

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.

Pancreas Transplantation Outcome Predictions-PTOP: A Risk Prediction Tool for Pancreas and Pancreas-Kidney Transplants Based on a European Cohort

Background

For patients with complicated type 1 diabetes having, for example, hypoglycemia unawareness and end-stage renal disease because of diabetic nephropathy, combined pancreas and kidney transplantation (PKT) is the therapy of choice. However, the shortage of available grafts and complex impact of risk factors call for individualized, impartial predictions of PKT and pancreas transplantation (PT) outcomes to support physicians in graft acceptance decisions.

Methods

Based on a large European cohort with 3060 PKT and PT performed between 2006 and 2021, the 3 primary patient outcomes time to patient mortality, pancreas graft loss, and kidney graft loss were visualized using Kaplan-Meier survival curves. Multivariable Cox proportional hazards models were developed for 5- and 10-y prediction of outcomes based on 26 risk factors.

Results

Risk factors associated with increased mortality included previous kidney transplants, rescue allocations, longer waiting times, and simultaneous transplants of other organs. Increased pancreas graft loss was positively associated with higher recipient body mass index and donor age and negatively associated with simultaneous transplants of kidneys and other organs. Donor age was also associated with increased kidney graft losses. The multivariable Cox models reported median C-index values were 63% for patient mortality, 62% for pancreas loss, and 55% for kidney loss.

Conclusions

This study provides an online risk tool at https://riskcalc.org/ptop for individual 5- and 10-y post-PKT and PT patient outcomes based on parameters available at the time of graft offer to support critical organ acceptance decisions and encourage external validation in independent populations.

Mortality assessment for pancreas transplants in the United States over the decade 2008-2018

BACKGROUND

Pancreas transplant is the only treatment that establishes normal glucose levels for patients diagnosed with diabetes. However, since 2005, no comprehensive analysis has compared survival outcomes of: (1) Simultaneous pancreas-kidney (SPK) transplant; (2) Pancreas after kidney (PAK) transplant; and (3) Pancreas transplant alone (PTA) to waitlist survival.

AIM

To explore the outcomes of pancreas transplants in the United States during the decade 2008-2018.

METHODS

Our study utilized the United Network for Organ Sharing Standard Transplant Analysis and Research file. Pre- and post-transplant recipient and waitlist characteristics and the most recent recipient transplant and mortality status were used. We included all patients with type I diabetes listed for pancreas or kidney-pancreas transplant between May 31, 2008 and May 31, 2018. Patients were grouped into one of three transplant types: SPK, PAK, or PTA.

RESULTS

The adjusted Cox proportional hazards models comparing survival between transplanted and non-transplanted patients in each transplant type group showed that patients who underwent an SPK transplant exhibited a significantly reduced hazard of mortality [hazard ratio (HR) = 0.21, 95% confidence intervals (CI): 0.19-0.25] compared to those not transplanted. Neither PAK transplanted patients (HR = 1.68, 95%CI: 0.99-2.87) nor PTA patients (HR = 1.01, 95%CI: 0.53-1.95) experienced significantly different hazards of mortality compared to patients who did not receive a transplant.

CONCLUSION

When assessing each of the three transplant types, only SPK transplant offered a survival advantage compared to patients on the waiting list. PKA and PTA transplanted patients demonstrated no significant differences compared to patients who did not receive a transplant.

Simultaneous pancreas-kidney transplantation: which graft warns the most?

BACKGROUND

Simultaneous pancreas-kidney transplantation (SPK) is still characterized by high rates of postoperative complications. This study aims to offer an in-depth characterization of early, medium-term, and late complications following SPK to derive insights for postoperative management and follow-up.

METHODS

Consecutive SPK transplantations were analysed. Pancreatic graft (P-graft)- and kidney graft (K-graft)-related complications were analysed separately. The global postoperative course was assessed in three timeframes (early, medium-term, and late) using the comprehensive complication index (CCI). Predictors of complications and early graft loss were explored.

RESULTS

Complications occurred in 61.2% of patients, and the 90-day mortality was 3.9%. The overall burden of complications was significantly high during admission (CCI 22.4 ± 21.1) and decreased gradually afterwards. P-graft-related complications burdened the most in the early postoperative course (CCI 11.6 ± 13.8); postoperative ileus and perigraft fluid collection were the most frequent complications, and pseudoaneurysms, haemorrhages, and bowel leaks were the major concerns. K-related complications were milder but represented the largest proportion of the CCI in the late postoperative timeframe (CCI 7.6 ± 13.6). No predictors of P-graft- or K-graft-related complications were found.

CONCLUSION

Pancreas graft-related complications represent the largest part of the clinical burden in the early postoperative timeframe but are negligible after 3 months. Kidney grafts have a relevant impact in the long term. The multidisciplinary approach to SPK recipients should be driven based on all graft-specific complications and tailored on a time-dependent basis.

Pancreas Transplantation: Current Challenges, Considerations, and Controversies

Pancreas transplantation (PTx) reestablishes an autoregulating source of endogenous insulin responsive to normal feedback controls. In addition to achieving complete β-cell replacement that frees the patient with diabetes from the need to monitor serum glucose and administer exogenous insulin, successful PTx provides counterregulatory hormone secretion and exocrine function. A functioning PTx mitigates glycemic variability, eliminates the daily stigma and burden of diabetes, restores normal glucose homeostasis in patients with complicated diabetes, and improves quality of life and life expectancy. The tradeoff is that it entails a major surgical procedure and requisite long-term immunosuppression. Despite the high likelihood of rendering patients euglycemic independent of exogenous insulin, PTx is considered a treatment rather than a cure. In spite of steadily improving outcomes in each successive era coupled with expansion of recipient selection criteria to include patients with a type 2 diabetes phenotype, a decline in PTx activity has occurred in the new millennium related to a number of factors including: (1) lack of a primary referral source and general acceptance by the diabetes care community; (2) absence of consensus criteria; and (3) access, education, and resource issues within the transplant community. In the author's experience, patients who present as potential candidates for PTx have felt as though they needed to circumvent the conventional diabetes care model to gain access to transplant options. PTx should be featured more prominently in the management algorithms for patients with insulin requiring diabetes who are failing exogenous insulin therapy or experiencing progressive diabetic complications regardless of diabetes type. Furthermore, all patients with diabetes and chronic kidney disease should undergo consideration for simultaneous pancreas-kidney transplantation independent of geography or location.

Appraising pancreatic fistula in pancreas transplantation: A comprehensive complication index based analysis of postoperative outcomes and predictors of graft survival

BACKGROUND

A definition of pancreatic fistula specifically addressing pancreas transplantation (PT) is lacking. This study sought to characterize pancreatic fistula in this setting and to define its clinical relevance on the postoperative course and long-term graft survival (GS).

METHODS

Consecutive simultaneous pancreas and kidney transplantations were analysed. The global postoperative course was assessed through the comprehensive complication index (CCI). PF was defined according to the original International Study Group for Pancreatic Surgery (ISGPS) definition. Predictors of poor postoperative course and GS were explored.

RESULTS

Seventy-eight patients were analysed. Surgical morbidity was 48.7%, with severe complications occurring in 39.7%. Ninety-day mortality was 2.6%. PF occurred in 56.6% of patients, although its average clinical burden was low and did not correlate with either early or long-term outcomes. Peri-graft fluid collections, postoperative day (POD) 1 drain fluid amylase (DFA) ≥ 2200 U/L, and POD 5 DFA/serum amylase ratio ≥7.0 independently correlated with poor postoperative course. Perigraft fluid collections were associated with reduced GS.

CONCLUSION

Conventionally defined pancreatic fistula is frequent following PT, although its clinical impact is negligible. To define clinically relevant PF, novel cut-offs for DFA might be pondered in a future series, while perigraft fluid collections should be strongly considered.

Breaking the limits of experimental pancreas transplantation: Working toward the clinical ideal graft

Pancreas transplantation is, at present, the only curative treatment for type-1 diabetes that maintains normoglycemia thus avoiding complications arising from poor glycemic control. Despite its great benefits, the number of pancreas transplants has decreased significantly since its inception in the late 1960s, largely due to demographic changes and the consequent suboptimal quality of donors. The selection criteria for pancreas donors mainly depend on morphological variables such as fatty infiltration, fibrosis, or edema, as well as both functional (amylase and lipase) and clinical variables of the donor. However, the final criterion in the decision-making process is the somewhat subjective assessment of a trained surgeon. That being said, the recent incorporation of graft perfusion machines into clinical practice seems to be changing the work dynamics of the donor organ retrieval team, facilitating decision-making based on objective morphological and functional criteria. Normothermic perfusion using perfusate with supplemental oxygen replicates near physiological parameters thus being a promising strategy for organ preservation. Nevertheless, optimum perfusion parameters are difficult to establish in pancreas transplantation given its complex vascular anatomy combined with an intrinsically low blood flow. The objective of this work is to analyze the results published in the recent literature relating to the considerations of ex-vivo normothermic graft perfusion machines and their usefulness in the field of pancreas transplantation.

Comparing Outcomes and Cost Between Pancreas Transplant and Standard of Care in Patients With Type 1 Diabetes

OBJECTIVES

Pancreas transplant is the only treatment that establishes normal glucose levels for patients diagnosed with diabetes. We analyzed the outcome of pancreas transplant alone (PTA) versus standard of care in the United States from 2008 to 2018. We also developed an economic model to analyze the cost-effectiveness of pancreas transplant versus continuing standard of care.

METHODS

We used the Scientific Registry of Transplant Recipients database and analyzed PTA recipient survival. Using those results, we developed a Markov model that followed a cohort of 40-year-old patients with type 1 diabetes over a 10-year time horizon. The primary outcomes were (i) the survival benefit of a pancreas transplant, (ii) quality-adjusted life-years (QALYs), and (iii) total costs.

RESULTS

We found no difference in survival advantage of PTA compared with standard of care (hazard ratio, 1.09; 95% confidence interval, 0.56-2.14). However, pancreas transplant ($172,823, 6.87 QALY) was cost-saving compared with standard of care ($232,897, 6.04 QALY) for type 1 diabetes. Pancreas transplantation was cost-effective in 95% of 10,000 simulations in probabilistic sensitivity analysis, using a $100,000/QALY willingness-to-pay threshold.

CONCLUSIONS

Although there is no difference in survival for PTA compared with standard of care, PTA is a cost-saving therapy for type 1 diabetes.

First World Consensus Conference on pancreas transplantation: Part II - recommendations

The First World Consensus Conference on Pancreas Transplantation provided 49 jury deliberations regarding the impact of pancreas transplantation on the treatment of diabetic patients, and 110 experts' recommendations for the practice of pancreas transplantation. The main message from this consensus conference is that both simultaneous pancreas-kidney transplantation (SPK) and pancreas transplantation alone can improve long-term patient survival, and all types of pancreas transplantation dramatically improve the quality of life of recipients. Pancreas transplantation may also improve the course of chronic complications of diabetes, depending on their severity. Therefore, the advantages of pancreas transplantation appear to clearly surpass potential disadvantages. Pancreas after kidney transplantation increases the risk of mortality only in the early period after transplantation, but is associated with improved life expectancy thereafter. Additionally, preemptive SPK, when compared to SPK performed in patients undergoing dialysis, appears to be associated with improved outcomes. Time on dialysis has negative prognostic implications in SPK recipients. Increased long-term survival, improvement in the course of diabetic complications, and amelioration of quality of life justify preferential allocation of kidney grafts to SPK recipients. Audience discussions and live voting are available online at the following URL address: http://mediaeventi.unipi.it/category/1st-world-consensus-conference-of-pancreas-transplantation/246.

Donor Predictors of Donor Pancreas Retrieval and Subsequent Solid Pancreas Transplantation in Australia and New Zealand from 2007 to 2016

BACKGROUND

Donor characteristics help guide donor pancreas acceptance for solid pancreas-kidney transplantation; however, these criteria vary worldwide. Such variation could result in nonuse of potentially transplantable organs. Using a registry cohort, we identified donor characteristics associated with donor pancreas retrieval and subsequent solid pancreas transplantation in Australia and New Zealand.

METHODS

Australia and New Zealand Organ Donor registry donor data from 2007 to 2016 were used to define cohort 1 (all donors authorized for pancreas retrieval) and cohort 2 (all retrieved donor pancreata considered for solid pancreas transplantation). Donor factors significantly associated with donor pancreas retrieval (cohort 1) and solid pancreas transplantation of retrieved donor pancreata (cohort 2) were determined via multivariable logistic regression.

RESULTS

Nonretrieval and nonuse of solid organ donor pancreas increased throughout the study period, and nonauthorization for pancreas donation remained stable. Donor body mass index, sex, and viral serology were associated with donor pancreas retrieval but not transplantation. Donor age, cause of death, donation after brain death status, terminal serum creatinine, and donor region were associated with both donor pancreas retrieval and acceptance for solid pancreas transplantation with donation after brain death status being the strongest predictor for both outcomes.

CONCLUSIONS

Donor age, cause of death, donation after brain death status, terminal serum creatinine, and donor region were associated with both donor pancreas retrieval and subsequent transplantation in Australia and New Zealand. Subsequent correlation of these factors with post-pancreas transplant outcomes would help guide pancreas transplant decisions and minimize nonuse of potentially usable donor pancreata.

Pancreas transplantation perceptions and practice: Results from a national US survey

BACKGROUND

Due to a substantial decline in pancreas transplantation (PT) across the United States over the past 15 years, we sought to understand the perceptions and practices of US PT programs.

METHODS

Surveys were sent to members of the American Society of Transplantation Surgeons and the American Society of Transplantation by email and professional society postings between August 2019 and November 2019.

RESULTS

One hundred twenty three responses were recorded from 56 unique programs. Program characteristics were obtained from the Scientific Registry of Transplant Recipients. Respondents were transplant surgeons (71%), transplant nephrologists (17%), trainees (9%), and allied professionals (3%). Programs were defined according to annual volume as: low (<5 PT/year), intermediate (6-20), or high (>20). High-volume programs reported that these factors were most important for increased PT: expansion of recipient selection, more aggressive donor utilization, and hiring of PT program-specific personnel. At both the program and national level, the vast majority (82% and 79%, respectively) felt the number of PTs currently performed are not in balance with patients' needs.

CONCLUSIONS

Overall, programs reported that the option of PT is not offered adequately to diabetic patients and that strategies to maintain higher PT volume are most evident at intermediate, and especially, high-volume programs.

Transplant Options for Patients With Diabetes and Advanced Kidney Disease: A Review

Optimal glycemic control in kidney transplant recipients with diabetes is associated with improved morbidity and better patient and allograft survival. Transplant options for patients with diabetes requiring insulin therapy and chronic kidney disease who are suitable candidates for kidney transplantation should include consideration of β-cell replacement therapy: pancreas or islet transplantation. International variation related to national regulatory policies exists in offering one or both options to suitable candidates and is further affected by pancreas/islet allocation policies and transplant waiting list dynamics. The selection of appropriate candidates depends on patient age, coexistent morbidities, the timing of referral to the transplant center (predialysis versus on dialysis) and availability of living kidney donors. Therefore, early referral (estimated glomerular filtration rate < 30 mL/min/1.73 m²) is of the utmost importance to ensure adequate time for informed decision making and thorough pretransplant evaluation. Obesity, cardiovascular disease, peripheral vascular disease, smoking, and frailty are some of the conditions that need to be addressed before acceptance on the transplant list, and ideally before dialysis becoming imminent. This review offers insights into selection of pancreas/islet transplant candidates by transplant centers and an update on posttransplant outcomes, which may have practice implications for referring nephrologists.

The impact of donor pancreas extraction time on graft survival and postoperative complications in pancreas transplant recipients

BACKGROUND

Simultaneous pancreas kidney transplantation (SPK) is the best therapeutic option for patients with diabetes mellitus type 1 and end-stage renal disease. Recently, donor organ extraction time has been shown to affect kidney and liver graft survival. This study aimed to assess the effect of pancreas donor extraction time on graft survival and postoperative complications.

METHODS

We retrospectively analyzed all pancreas transplants performed in two Eurotransplant centers. The association of pancreas extraction time with pancreas graft survival was analyzed by a Cox proportional hazards regression analysis after 3 months, 1 and 5 year. Besides, the effect of pancreas extraction time on the incidence of severe postoperative complications was analyzed.

RESULTS

A total of 317 pancreas transplants were included in this study. Death-censored pancreas graft survival was 85.7% after one year and 76.7% after five years. Median pancreas donor extraction time was 64 min [IQR: 52-79 min]. After adjustment for potential confounders, death censored graft survival after 30 days (HR 1.01, 95% CI 0.9-1.03 (p = 0.23), 1 year (HR 1.01, 95% CI 0.99-1.03 (p = 0.22) and 5 years (HR 1.00, 95% CI 0.99-1.02 (p = 0.57) was not associated with pancreas donor extraction time. However, extraction time was significantly associated with a higher incidence of Clavien-Dindo ≥3 complications compared to Clavien-Dindo 1 + 2 complications: OR 1.012, 95% CI 1.00-1.02 (p = 0.039).

CONCLUSIONS

Our findings suggest that although no effect on graft survival was found, limiting pancreas extraction time can have a significant impact on lowering postoperative complications.

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.

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.