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

Elevated liver enzymes at the time of deceased donor organ donation do not affect recipient or pancreas allograft survival following pancreas transplantation

BACKGROUND

There is a lack of data on the impact of donor liver function tests (LFTs) on pancreas transplantation outcomes. Understanding their contribution could expand the donor pool.

METHODS

Using the UNOS database, data from January 2010-2022 was retrospectively analyzed. Multivariable cox regressions were performed to evaluate the association between LFTs (AST, ALT and total bilirubin levels), graft failure and mortality up to three years post-transplant.

RESULTS

9138 pancreas transplants were completed. Multivariate analysis showed no association between donor AST values > 500 U/L and increased rates of graft failure (p = 0.826) or mortality (p = 0.836). Similar findings were noted for donor ALT values > 500 U/L (p = 0.522 and p = 0.997, respectively). There was no correlation with graft failure (p = 0.322) or mortality (p = 0.423) for total bilirubin levels >3 mg/dL.

CONCLUSION

LFTs in the deceased pancreas donor did not increase risk of graft failure or mortality following pancreas transplantation. Elevated LFTs should not serve as absolute contraindications to transplant.

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.

Influence of donor and recipient sex on outcomes following simultaneous pancreas-kidney transplantation in the new millennium: Single-center experience and review of the literature

INTRODUCTION

The influence of sex on outcomes following simultaneous pancreas-kidney transplantation (SPKT) in the modern era is uncertain.

METHODS

We retrospectively studied 255 patients undergoing SPKT from 11/2001 to 8/2020. Cases were stratified according to donor (D) sex, recipient (R) sex, 4 D/R sex categories, and D/R sex-matched versus mismatched.

RESULTS

D-male was associated with slightly higher patient (p = .08) and kidney (p = .002) but not pancreas (p = .23) graft survival rates (GSR) compared to D-female. There were no differences in recipient outcomes other than slightly higher pancreas thrombosis (8% R-female vs. 4.2% R-male, p = .28) and early relaparotomy rates in female recipients (38% R-female vs. 29% R-male, p = .14). When analyzing the 4 D/R sex categories, the two D-male groups had higher kidney GSRs compared to the two D-female groups (p = .01) whereas early relaparotomy and pancreas thrombosis rates were numerically higher in the D-female/R-female group compared to the other three groups. Finally, there were no significant differences in outcomes between sex-matched and sex-mismatched groups although overall survival outcomes were lower with female donors irrespective of recipient sex.

CONCLUSIONS

The influence of D/R sex following SPKT is subject to multiple confounding issues but survival rates appear to be higher in D-male/R-male and lower in D-female/R-male categories.

Improved surgical outcomes following simultaneous pancreas-kidney transplantation in the contemporary era

BACKGROUND

Complications leading to early technical failure have been the Achilles' heel of simultaneous pancreas-kidney transplantation (SPKT). The study purpose was to analyze longitudinally our experience with early surgical complications following SPKT with an emphasis on changes in practice that improved outcomes in the most recent era.

STUDY DESIGN

Single center retrospective review of all SPKTs from 11/1/01 to 8/12/20 with enteric drainage. Early relaparotomy was defined as occurring within 3 months of SPKT. Patients were stratified into two sequential eras: Era 1 (E1): 11/1/01-5/30/13; Era 2 (E2) 6/1/13-8/12/20 based on changes in practice that occurred pursuant to donor age and pancreas cold ischemia time (CIT).

RESULTS

255 consecutive SPKTs were analyzed (E1, n = 165; E2, n = 90). E1 patients received organs from older donors (mean E1 27.3 vs. E2 23.1 years) with longer pancreas cold CITs) (mean E1 16.1 vs. E2 13.3 h, both p < .05). E1 patients had a higher early relaparotomy rate (E1 43.0% vs. E2 14.4%) and were more likely to require allograft pancreatectomy (E1 9.1% vs. E2 2.2%, both p < .05). E2 patients underwent systemic venous drainage more frequently (E1 8% vs. E2 29%) but pancreas venous drainage did not influence either relaparotomy or allograft pancreatectomy rates. The most common indications for early relaparotomy in E1 were allograft thrombosis (11.5%) and peri-pancreatic phlegmon/abscess (8.5%) whereas in E2 were thrombosis, pancreatitis/infection, and bowel obstruction (each 3%).

CONCLUSION

Maximizing donor quality (younger donors) and minimizing pancreas CIT are paramount for reducing early surgical complications following SPKT.

Pancreas Transplantation in Minorities including Patients with a Type 2 Diabetes Phenotype

Background: Prior to year 2000, the majority of pancreas transplants (PTx) were performed as simultaneous pancreas-kidney transplants (SPKTs) in Caucasian adults with end stage renal failure secondary to type 1 diabetes mellitus (T1DM) who were middle-aged. In the new millennium, improving outcomes have led to expanded recipient selection that includes patients with a type 2 diabetes mellitus (T2DM) phenotype, which excessively affects minority populations. Methods: Using PubMed® to identify appropriate citations, we performed a literature review of PTx in minorities and in patients with a T2DM phenotype. Results: Mid-term outcomes with SPKT in patients with uremia and circulating C-peptide levels (T2DMphenotype) are comparable to those patients with T1DM although there may exist a selection bias in the former group. Excellent outcomes with SPKT suggests that the pathophysiology of T2DM is heterogeneous with elements consisting of both insulin deficiency and resistance related to beta-cell failure. As a result, increasing endogenous insulin (Cp) production following PTx may lead to freedom checking blood sugars or taking insulin, better metabolic counter-regulation, and improvements in quality of life and life expectancy compared to other available treatment options. Experience with solitary PTx for T2DM or in minorities is limited but largely mirrors the trends reported in SPKT. Conclusions: PTx is a viable treatment option in patients with pancreas endocrine failure who are selected appropriately regardless of diabetes type or recipient race. This review will summarize data that unconventional patient populations with insulin-requiring diabetes may gain value from PTx with an emphasis on contemporary experiences and appropriate selection in minorities in the new millennium.

Simultaneous pancreas‐kidney transplantation in Caucasian versus African American patients: Does recipient race influence outcomes?

The influence of African American (AA) recipient race on outcomes following simultaneous pancreas‐kidney transplantation (SPKT) is uncertain.

Do pretransplant C-peptide levels predict outcomes following simultaneous pancreas-kidney transplantation? A matched case-control study

Following simultaneous pancreas-kidney transplantation (SPKT), survival outcomes are reported as equivalent in patients with detectable pretransplant C-peptide levels (Cp+) and a "type 2″ diabetes mellitus (DM) phenotype compared to type 1 (Cp negative [Cp-]) DM. We retrospectively compared 46 Cp+ patients pretransplant (≥2.0 ng/mL, mean 5.4 ng/mL) to 46 Cp- (level < 0.5 ng/mL) case controls matched for recipient age, gender, race, and transplant date. Early outcomes were comparable. Actual 5-year patient survival (91% versus 94%), kidney graft survival (69% versus 86%, p = .15), and pancreas graft survival (60% versus 86%, p = .03) rates were lower in Cp+ versus Cp- patients, respectively. The Cp+ group had more pancreas graft failures due to insulin resistance (13% Cp+ versus 0% Cp-, p = .026) or rejection (17% Cp+ versus 6.5% Cp-, p = .2). Post-transplant weight gain > 5 kg occurred in 72% of Cp+ versus 26% of Cp- patients (p = .0001). In patients with functioning grafts, mean one-year post-transplant HbA1c levels (5.0 Cp+ versus 5.2% Cp-) were comparable, whereas Cp levels were higher in Cp+ patients (5.0 Cp+ versus 2.6 ng/mL Cp-). In this matched case-control study, outcomes were inferior in Cp+ compared to Cp- patients following SPKT, with post-transplant weight gain, insulin resistance, and rejection as potential mitigating factors.

Therapeutics for type-2 diabetes mellitus: a glance at the recent inclusions and novel agents under development for use in clinical practice

Diabetes mellitus (DM) is a chronic, progressive, and multifaceted illness resulting in significant physical and psychological detriment to patients. As of 2019, 463 million people are estimated to be living with DM worldwide, out of which 90% have type-2 diabetes mellitus (T2DM). Over the years, significant progress has been made in identifying the risk factors for developing T2DM, understanding its pathophysiology and uncovering various metabolic pathways implicated in the disease process. This has culminated in the implementation of robust prevention programmes and the development of effective pharmacological agents, which have had a favourable impact on the management of T2DM in recent times. Despite these advances, the incidence and prevalence of T2DM continue to rise. Continuing research in improving efficacy, potency, delivery and reducing the adverse effect profile of currently available formulations is required to keep pace with this growing health challenge. Moreover, new metabolic pathways need to be targeted to produce novel pharmacotherapy to restore glucose homeostasis and address metabolic sequelae in patients with T2DM. We searched PubMed, MEDLINE, and Google Scholar databases for recently included agents and novel medication under development for treatment of T2DM. We discuss the pathophysiology of T2DM and review how the emerging anti-diabetic agents target the metabolic pathways involved. We also look at some of the limiting factors to developing new medication and the introduction of unique methods, including facilitating drug delivery to bypass some of these obstacles. However, despite the advances in the therapeutic options for the treatment of T2DM in recent years, the industry still lacks a curative agent.

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.

Development of ex situ normothermic reperfusion as an innovative method to assess pancreases after preservation

Static cold storage (SCS) is the standard method for pancreas preservation prior to transplantation; however, it does not permit organ assessment. Normothermic reperfusion (NR) is utilized clinically for other organs to assess viability. Our aim was to develop NR using normothermic machine perfusion technique to simulate reperfusion at the time of transplantation, enabling evaluation of oxygenated hypothermic machine perfusion (HMPO2) as a newer strategy to optimize pancreas preservation. 13 porcine pancreases procured after circulatory death were divided into 3 groups: 4 pancreases preserved using SCS, and 2 groups preserved by HMPO2 (n = 4 and n = 5, differing by type of preservation solution). Duration of perfusion or cold storage was 6 hours before the 1-hour assessment using NR. Outcome measures were perfusion characteristics, biochemistry and change in tissue water mass as oedema assessment. During NR, the HMPO2 groups demonstrated better perfusion characteristics, normal macroscopic appearances, decreased water mass and one HMPO2 group demonstrated a response to glucose stimulation. Conversely, the SCS group showed an increased water mass and developed early macroscopic appearances of oedema, interstitial haemorrhage and minimal portal outflow. This study suggests that ex situ assessment of pancreases by NR is promising, and that HMPO2 may be better than SCS.

[Pancreas transplantation-clinic, technique, and histological assessment]

BACKGROUND

In Germany pancreas transplants are performed in only a few selected and specialized centres, usually combined with a kidney transplant. Knowlegde of the indications for and techniques of transplantation as well as of the histopathological assessment for rejection in pancreas and duodenal biopsies is not very widespread.

AIM

To give an overview of the development and status quo in pancreas-kidney-transplantation in Germany summarizing the experience of the largest German pancreas transplant centre and to give a résumé of the results of histological diagnoses of biopsy specimens submitted between 06/2017 and 12/2020. Moreover, a detailed description and illustration of histological findings is included.

MATERIAL AND METHODS

A thorough literature search for aspects of the history, technique and indication for pancreas transplantation was performed and discussed in the context of the local experience and technical particularities specific for the transplant centre in Bochum. The occurrence of complications was compared with international reports. Results of pancreas and duodenal biopsies submitted to Erlangen between 06/2017 and 12/2020 for histological evaluation, which were evaluated according to the Banff classification, were summarized. For a better understanding key histological findings of pancreas rejection and differential diagnoses were illustrated and discussed.

RESULTS

A total of 93 pancreas transplant specimens and 3 duodenal biopsies were included. 34.4% of pancreas specimens did not contain representative material for a diagnosis. In the remaining 61 biopsies 24.6% showed no rejection, 62.3% were diagnosed with acute T-cell mediated rejection (TCMR) and 8.2% with signs suspicious of antibody-mediated rejection (ABMR). Acute acinary epithelial injury was seen in 59%, pancreatitis in 8.2% and allograft fibrosis was reported in as many as 54.1%. Calcineurin-inhibitor toxicity was discussed in only 4.9%.

CONCLUSION

Pancreas-kidney-transplantation and standardized histological assessment of the transplanted pancreas or rarely duodenum with reporting according to the updated Banff classification of pancreas transplants or previous reports of duodenal rejection are important mainstays in the management of patients with diabetes.

Solid pancreas transplant outcomes with increased donor and recipient ages compared to reference ages: A systematic review

BACKGROUND

Increased recipient and donor age are associated with worse solid organ pancreas transplant outcomes. However, donor and recipient age criteria vary between jurisdictions. We systematically reviewed studies reporting the association between transplanting older recipients and donors beyond current Transplantation Society of Australia and New Zealand (TSANZ) limits with solid pancreas transplant outcomes.

METHODS

Studies comparing transplant outcomes between a reference-age and an older-age donor (>45 years) or recipient (≥50 years) cohort for solid pancreas transplantation were included. Primary outcomes were pancreas/kidney graft and patient survival at one and five years. Secondary outcomes were post-transplant complications (graft thrombosis, acute rejection and relaparotomy rates).

RESULTS

11 studies were included (two studies assessing solid pancreas outcomes between older vs reference-aged donors and nine studies assessing outcomes between older vs reference-aged recipients). Seven of 11 studies were judged to be at high risk of bias. Primary and secondary outcomes were not significantly different between recipient age groups in nine studies. A sensitivity analysis of older vs reference-aged studies excluding studies at high risk of bias also showed non-inferior primary and secondary outcomes at one year. Two studies comparing outcomes by donor age showed worse graft survival but non-inferior patient survival with older donors.

CONCLUSION

Increased donor or recipient age alone should not absolutely contraindicate solid pancreas transplantation, especially if other risk predictors are minimised. This article is protected by copyright. All rights reserved.

Results from an International Survey of Donor and Recipient Eligibility for Solid Organ Pancreas Transplantation

Background

Current solid organ pancreas transplantation protocols have differing donor criteria for donor pancreas acceptance and recipient eligibility criteria for transplant workup. We quantified this variation and compared current Australia and New Zealand (ANZ) solid pancreas transplant eligibility criteria with current international practice.

Material/Methods

A survey of donor and recipient eligibility criteria for solid pancreas transplantation was disseminated to 85 transplant units in 23 countries. Responses were grouped by regions (ANZ, North America, Eurotransplant, Europe, United Kingdom) and analyzed for significant differences between regions and for ANZ compared to all other regions.

Results

Responding UK pancreas transplant units reported the highest mean donor upper age limit (61 years old) and the highest mean donation after cardiac death donor (DCD) age limit (55 years old). All responding UK and USA units utilized DCD pancreas donors and accepted suitable type 2 diabetes (T2DM) recipients for pancreas transplantation; however, this was less common among responding European or Eurotransplant units. ANZ mean standard and DCD pancreas donor upper age limits (47 and 35 years old, respectively) were lower compared to all other regions (54 years old and 48 years old, respectively).

Conclusions

Pancreas donor age limits, DCD pancreas donor utilization, and transplanting T2DM recipients differ between responding pancreas transplant units. ANZ units have more conservative donor upper age limits compared to other responding units. Increased utilization of DCD pancreas donors and T2DM recipients while standardizing pancreas donor age limits might increase donor numbers and improve access to solid pancreas transplantation both locally and abroad.

Recipient age and outcomes following simultaneous pancreas-kidney transplantation in the new millennium: Single-center experience and review of the literature

The influence of recipient age on outcomes following simultaneous pancreas-kidney transplantation (SPKT) in the modern era is uncertain.

METHODS

We retrospectively studied 255 patients undergoing SPKT from 11/01 to 8/20. Recipients were stratified according to age group: age <30 years (n = 16); age 30-39 years (n = 91); age 40-49 years (n = 86) and age ≥50 years (n = 62 [24.3%], including 9 patients ≥60 years of age).

RESULTS

Three-month and one-year outcomes were comparable. The eight-year patient survival rate was lowest in the oldest age group (47.6% vs 78% in the 3 younger groups combined, p < .001). However, eight-year kidney and pancreas graft survival rates were comparable in the youngest and oldest age groups combined (36.5% and 32.7%, respectively), but inferior to those in the middle 2 groups combined (62% and 50%, respectively, both p < .05). Death-censored kidney and pancreas graft survival rates increased from youngest to oldest recipient age category because of a higher incidence of death with functioning grafts (22.6% in oldest group compared to 8.3% in the 3 younger groups combined, p = .005).

CONCLUSIONS

Recipient age did not appear to significantly influence early outcomes following SPKT. Late outcomes are similar in younger and older recipients, but inferior to the middle 2 age groups.

Risk indices predicting graft use, graft and patient survival in solid pancreas transplantation: a systematic review

BACKGROUND

Risk indices such as the pancreas donor risk index (PDRI) and pre-procurement pancreas allocation suitability score (P-PASS) are utilised in solid pancreas transplantation however no review has compared all derived and validated indices in this field. We systematically reviewed all risk indices in solid pancreas transplantation to compare their predictive ability for transplant outcomes.

METHODS

Medline Plus, Embase and the Cochrane Library were searched for studies deriving and externally validating risk indices in solid pancreas transplantation for the outcomes of pancreas and patient survival and donor pancreas acceptance for transplantation. Results were analysed descriptively due to limited reporting of discrimination and calibration metrics required to assess model performance.

RESULTS

From 25 included studies, discrimination and calibration metrics were only reported in 88% and 38% of derivation studies (n = 8) and in 25% and 25% of external validation studies (n = 12) respectively. 21 risk indices were derived with mild to moderate ability to predict risk (C-statistics 0.52-0.78). Donor age, donor body mass index (BMI) and donor gender were the commonest covariates within derived risk indices. Only PDRI and P-PASS were subsequently externally validated, with variable association with post-transplant outcomes. P-PASS was not associated with pancreas graft survival.

CONCLUSION

Most of the risk indices derived for use in solid pancreas transplantation were not externally validated (90%). PDRI and P-PASS are the only risk indices externally validated for solid pancreas transplantation, and when validated without reclassification measures, are associated with 1-year pancreas graft survival and donor pancreas acceptance respectively. Future risk indices incorporating recipient and other covariates alongside donor risk factors may have improved predictive ability for solid pancreas transplant outcomes.

Review 1: Lung transplant-from donor selection to graft preparation

For various end-stage lung diseases, lung transplantation remains one of the only viable treatment options. While the demand for lung transplantation has steadily risen over the last few decades, the availability of donor grafts is limited, which have resulted in progressively longer waiting lists. In the early years of lung transplantation, only the 'ideal' donor grafts are considered for transplantation. Due to the donor shortages, there is ongoing discussion about the safe use of 'suboptimal' grafts to expand the donor pool. In this review, we will discuss the considerations around donor selection, donor-recipient matching, graft preparation and graft optimisation.

Impact of donor cardiopulmonary resuscitation on the outcome of simultaneous pancreas-kidney transplantation-a retrospective study

Previous cardiac arrest in brain-dead donors has been discussed as a potential risk factor in pancreas transplantation (PT), leading to a higher rate of organ refusal. This study aimed to assess the impact of cardiopulmonary resuscitation (CPR) in brain-dead donors on pancreas transplant outcome. A total of 518 type 1 diabetics underwent primary simultaneous pancreas-kidney (SPK) transplantation at our center between 1994 and 2018. Patients were divided into groups, depending on whether their donor had been resuscitated or not. A total of 91 (17.6%) post-CPR donors had been accepted for transplantation (mean duration of cardiac arrest, 19.4 ± 15.6 min). Those donors were younger (P < 0.001), had lower pancreas donor risk index (PDRI, P = 0.003), and had higher serum creatinine levels (P = 0.021). With a median follow-up of 167 months (IQR 82-229), both groups demonstrated comparable short- and long-term patient and graft survival. The resuscitation time (<20 min vs. ≥20 min) also showed no impact, with similar survival rates for both groups. A multivariable Cox regression analysis suggested no statistically significant association between donor CPR and patient or graft survival. Our results indicate that post-CPR brain-dead donors are suitable for PT without increasing the risk of complications.

Beneficial effects of the novel marine oxygen carrier M101 during cold preservation of rat and human pancreas

Ischaemia impairs organ quality during preservation in a time‐dependent manner, due to a lack of oxygen supply. Its impact on pancreas and islet transplantation outcome has been demonstrated by a correlation between cold ischaemia time and poor islet isolation efficiency. Our goal in the present study was to improve pancreas and islet quality using a novel natural oxygen carrier (M101, 2 g/L), which has been proven safe and efficient in other clinical applications, including kidney transplantation, and for several pre‐clinical transplantation models. When M101 was added to the preservation solution of rat pancreas during ischaemia, a decrease in oxidative stress (ROS), necrosis (HMGB1), and cellular stress pathway (p38 MAPK)activity was observed. Freshly isolated islets had improved function when M101 was injected in the pancreas. Additionally, human pancreases exposed to M101 for 3 hours had an increase in complex 1 mitochondrial activity, as well as activation of AKT activity, a cell survival marker. Insulin secretion was also up‐regulated for isolated islets. In summary, these results demonstrate a positive effect of the oxygen carrier M101 on rat and human pancreas during preservation, with an overall improvement in post‐isolation islet quality.

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.

Proton MR spectroscopy of human pancreas allografts

OBJECTIVE

To estimate pancreas graft relaxation times and concentrations of total fat, and the intracellular lipids of non-adipose pancreatic cells (NAPC) using proton (¹H) magnetic resonance spectroscopy (MRS) during cold preservation.

MATERIALS AND METHODS

Grafts from 11 human donors were investigated. Each pancreas was perfused in situ with histidine-tryptophan-ketoglutarate (HTK) or with University of Wisconsin solution and placed into a transport container. Temperature of the grafts was maintained at 4 ± 2 °C during transport to our hospital and MR scanning. A 1.5 T clinical scanner was used for the measurements. Single-voxel PRESS spectra were acquired using transmit-receiver head coil.

RESULTS

Relaxation times were measured for lipid (-CH₂-)_n (T₁, 287 ± 60 ms; T₂, 27 ± 4 ms), and tissue water (T₁, 670 ± 69 ms; T₂, 77 ± 17 ms). Average total fat, and intracellular lipids of NAPC concentrations were 79.2 ± 100.8 (range 2.4-304.4), and 2.9 ± 1.2 mmol/kg ww, respectively.

CONCLUSION

We have shown that ¹H-MRS is a useful tool for the estimation of pancreas graft lipid concentrations. Total pancreatic fat and especially content of intracellular lipids of NAPC are valuable measures for inspection of graft quality prior to transplantation or islet of Langerhans isolation.

Impact of Deceased Donor Cardiac Arrest Time on Postpancreas Transplant Graft Function and Survival

Introduction

Transplantation of pancreas allografts from donors that have experienced preprocurement cardiopulmonary arrest (PPCA) is not common, though use of PPCA grafts is routine in liver and kidney transplantation. This article reviews a large number of PPCA pancreas grafts at a single center and reports posttransplant outcomes including early graft dysfunction, length of hospital stay, rejection, and early and late graft survival.

Methods

Preprocurement cardiopulmonary arrest, arrest time, and donor and recipient pancreatic enzyme levels were collected from electronic and written medical records. The PPCA donors were stratified into 4 groups: none, less than 20 minutes, 20-39 minutes, and 40 minutes or greater. Graft survival was assessed at 7 and 90 days and at 1 year. Long-term graft survival was assessed by Cox regression analysis.

Results

The records of 606 pancreas transplants were reviewed, including 328 (54%) simultaneous pancreas and kidney transplants. Preprocurement cardiopulmonary arrest occurred in 176 donors (29%; median time, 20 minutes). Median peak donor lipase was higher in PPCA donors (40 μ/L vs 29 μ/L, P = 0.02). Posttransplant, peak recipient amylase, and lipase levels were similar (P = 0.63). Prolonged arrest time (>40 minutes) was associated with higher donor peak lipase and lower recipient peak amylase (P = 0.05 for both). Stratified by donor arrest time, there was no difference in 7-day, 90-day, or 1-year graft survival. Cox regression comparing the 4 groups demonstrated no statistical difference in 10-year survival.

Conclusions

These results support transplantation of pancreas allografts from PPCA donors. Prolonged asystole was associated with higher peak donor serum lipase but lower peak recipient serum amylase. There were no differences in allograft survival.

Extracellular matrix scaffold and hydrogel derived from decellularized and delipidized human pancreas

Extracellular matrix (ECM) plays an important developmental role by regulating cell behaviour through structural and biochemical stimulation. Tissue-specific ECM, attained through decellularization, has been proposed in several strategies for tissue and organ replacement. Decellularization of animal pancreata has been reported, but the same methods applied to human pancreas are less effective due to higher lipid content. Moreover, ECM-derived hydrogels can be obtained from many decellularized tissues, but methods have not been reported to obtain human pancreas-derived hydrogel. Using novel decellularization methods with human pancreas we produced an acellular, 3D biological scaffold (hP-ECM) and hydrogel (hP-HG) amenable to tissue culture, transplantation and proteomic applications. The inclusion of a homogenization step in the decellularization protocol significantly improved lipid removal and gelation capability of the resulting ECM, which was capable of gelation at 37 °C in vitro and in vivo, and is cytocompatible with a variety of cell types and islet-like tissues in vitro. Overall, this study demonstrates the characterisation of a novel protocol for the decellularization and delipidization of human pancreatic tissue for the production of acellular ECM and ECM hydrogel suitable for cell culture and transplantation applications. We also report a list of 120 proteins present within the human pancreatic matrisome.

Human Proislet Peptide Promotes Pancreatic Progenitor Cells to Ameliorate Diabetes Through FOXO1/Menin-Mediated Epigenetic Regulation

We investigated how human proislet peptide (HIP) regulates differentiation of human fetus-derived pancreatic progenitor cells (HFPPCs) and explored the potential link between HIP signaling and the menin pathway, which is key to regulating pancreatic islet differentiation. The data show that HIP promoted expression of proislet transcription factors (TFs), including PDX-1, MAFA, and NKX6.1, as well as other maturation markers of β-cells, such as insulin, GLUT2, KIR6.2, SUR1, and VDCC. Moreover, HIP increased insulin content and promoted the ability of HFPPCs to normalize blood glucose in diabetic mice. HIP inhibited the TF FOXO1 by increasing AKT-mediated phosphorylation. HIP-induced repression of FOXO1 suppressed menin expression, leading to reducing menin binding to the promoter of the three key proislet TFs, decreasing recruitment of H3K9 methyltransferase SUV39H1, and thus reducing repressive H3K9me3 at the promoter. These coordinated actions lead to increased expression of the proislet TFs, resulting in induction of HFPPC differentiation. Consistently, constitutive activation of FOXO1 blocks HIP-induced transcription of these TFs. Together, these studies unravel the crucial role of the HIP/AKT/FOXO/menin axis in epigenetically controlling expression of proislet TFs, regulating the differentiation of HFPPCs, and normalizing blood glucose in diabetic mice.

Compared efficacy of preservation solutions on the outcome of liver transplantation: Meta-analysis

AIM

To compare the effects of the four most commonly used preservation solutions on the outcome of liver transplantations.

METHODS

A systematic literature search was performed using MEDLINE, Scopus, EMBASE and the Cochrane Library databases up to January 31st, 2017. The inclusion criteria were comparative, randomized controlled trials (RCTs) for deceased donor liver (DDL) allografts with adult and pediatric donors using the gold standard University of Wisconsin (UW) solution or histidine-tryptophan-ketoglutarate (HTK), Celsior (CS) and Institut Georges Lopez (IGL-1) solutions. Fifteen RCTs (1830 livers) were included; the primary outcomes were primary non-function (PNF) and one-year post-transplant graft survival (OGS-1).

RESULTS

All trials were homogenous with respect to donor and recipient characteristics. There was no statistical difference in the incidence of PNF with the use of UW, HTK, CS and IGL-1 (RR = 0.02, 95%CI: 0.01-0.03, P = 0.356). Comparing OGS-1 also failed to reveal any difference between UW, HTK, CS and IGL-1 (RR = 0.80, 95%CI: 0.80-0.80, P = 0.369). Two trials demonstrated higher PNF levels for UW in comparison with the HTK group, and individual studies described higher rates of biliary complications where HTK and CS were used compared to the UW and IGL-1 solutions. However, the meta-analysis of the data did not prove a statistically significant difference: the UW, CS, HTK and IGL-1 solutions were associated with nearly equivalent outcomes.

CONCLUSION

Alternative solutions for UW yield the same degree of safety and effectiveness for the preservation of DDLs, but further well-designed clinical trials are warranted.

Simultaneous pancreas-kidney transplantation. Experience of the Doce de Octubre Hospital

INTRODUCTION

Simultaneous pancreas-kidney transplantation (SPKT) constitutes the therapy of choice for diabetes type1 or type2 associated with end-stage renal disease, because is the only proven method to restore normo-glicemic control in the diabetic patient.

METHODS

Retrospective and descriptive study of a series of 175 patients who underwent SPKT from March 1995 to April 2016. We analyze donor and recipient characteristics, perioperative variables and immunosuppression, post-transplant morbi-mortality, patient and graft survival, and risk factors related with patient and graft survival.

RESULTS

Median age of the donors was 28years and mean age of recipients was 38.8±7.3years, being 103 males and 72 females. Enteric drainage of the exocrine pancreas was performed in 113 patients and bladder drainage in 62. Regarding post-transplant complications, the overall rate of infections was 70.3%; graft pancreatitis 26.3%; intraabdominal bleeding 17.7%; graft thrombosis 12.6%; and overall pancreas graft rejection 10.9%. The causes of mortality were mainly cardiovascular and infectious complications. Patient survival at 1, 3 and 5-year were 95.4%, 93% and 92.4%, respectively, and pancreas graft survival at 1, 3 and 5-year were 81.6%, 77.9% y 72.3%, respectively.

CONCLUSIONS

In our 20-year experience of simultaneous pancreas-kidney transplantation, the morbidity rate, and 5-year patient and pancreas graft survivals were similar to those previously reported from the international pancreas transplant registries.

Guidelines for the assessment and acceptance of potential brain-dead organ donors

Organ transplantation is the only alternative for many patients with terminal diseases. The increasing disproportion between the high demand for organ transplants and the low rate of transplants actually performed is worrisome. Some of the causes of this disproportion are errors in the identification of potential organ donors and in the determination of contraindications by the attending staff. Therefore, the aim of the present document is to provide guidelines for intensive care multi-professional staffs for the recognition, assessment and acceptance of potential organ donors.

Pre-transplantation 31P-magnetic resonance spectroscopy for quality assessment of human pancreatic grafts - A feasibility study

OBJECTIVE

To investigate the feasibility of using ³¹P-MRS for objective non-invasive quality assessment of human pancreas grafts prior to transplantation or islet isolation.

MATERIALS AND METHODS

Pancreata from 5 human donors, 3 males and 2 females, aged 49-78years, with body mass index (BMI) 22-31kg/m², were included. Pancreata were perfused with histidine-tryptophan-ketoglutarate solution during procurement and stored in hypothermic condition (4°C) for 21-44h. During the period of hypothermic storage repeated spectra were obtained for each graft by ³¹P-MRS (1.5Tesla) to measure the cold ischemia time (CIT) dependent changes of the phosphorous metabolites adenosine triphosphate (ATP), phosphomonoesters (PME), phosphodiesters (PDE) and inorganic phosphate (Pi), in the grafts. Graft temperature was measured immediately before and after MR-examination. Reference spectrum for non-viable tissue was obtained after graft exposure to room temperature.

RESULTS

PME/Pi, PDE/Pi and ATP/Pi spectral intensities ratios decreased with increasing CIT, reflecting the decreased viability of the grafts. PME/Pi ratio was the most discriminatory variable at prolonged CIT. ³¹P-MRS could be performed without significantly increasing graft temperature.

CONCLUSIONS

³¹P-MRS may provide quantitative parameters for evaluating graft viability ex vivo, and is a promising tool for objective non-invasive assessment of the quality of human pancreas grafts prior to transplantation or islet isolation.

Forkhead Protein FoxO1 Acts as a Repressor to Inhibit Cell Differentiation in Human Fetal Pancreatic Progenitor Cells

Our colleagues have reported previously that human pancreatic progenitor cells can readily differentiate into insulin-containing cells. Particularly, transplantation of these cell clusters upon in vitro induction for 3-4 w partially restores hyperglycemia in diabetic nude mice. In this study, we used human fetal pancreatic progenitor cells to identify the forkhead protein FoxO1 as the key regulator for cell differentiation. Thus, induction of human fetal pancreatic progenitor cells for 1 week led to increase of the pancreatic β cell markers such as Ngn3, but decrease of stem cell markers including Oct4, Nanog, and CK19. Of note, FoxO1 knockdown or FoxO1 inhibitor significantly upregulated Ngn3 and insulin as well as the markers such as Glut2, Kir6.2, SUR1, and VDCC, which are designated for mature β cells. On the contrary, overexpression of FoxO1 suppressed the induction and reduced expression of these β cell markers. Taken together, these results suggest that FoxO1 may act as a repressor to inhibit cell differentiation in human fetal pancreatic progenitor cells.

Management of Graft Duodenal Leak in Simultaneous Pancreas Kidney Transplant-a Case Report from India and Review of Literature

Pancreatic transplantation is currently the only effective cure for Type 1 diabetes mellitus. It allows long-term glycemic control without exogenous insulin and amelioration of secondary diabetic complications. In India, pancreas transplant has not yet established with only a single successful transplant reported so far in the literature. We report a 24-year-old Type 1 diabetic patient with renal failure who underwent a simultaneous pancreas kidney transplant. On postoperative day 15, he had leak from the graft duodenal stump for which a tube duodenostomy and proximal diversion enterostomy was done. He had a high output pancreatic fistula following the procedure which was managed conservatively. The tube duodenostomy was removed at three and half months and enterostomy closure with restoration of bowel continuity was done at 6 months. After a follow up of 7 months, patient is doing well with a serum creatinine of 0.8 mg/dl and normal blood sugars, not requiring any exogenous insulin or oral hypoglycemic drugs. Managing patients with graft duodenal complications after pancreas transplant is challenging. Tube duodenostomy is a safe option in management of duodenal leak, although can lead to a persistent pancreatic fistula. A proximal diversion enterostomy allows early oral feeding and avoids the cost as well as the long term complications associated with parenteral nutrition.

Donor Characteristics of Pancreas Transplantation in Australia and New Zealand: A Cohort Study 1984-2014

Background

The aim of this study was to audit the characteristics of pancreas donors over time in Australia and New Zealand. Pancreas transplantation was introduced in Australian and New Zealand in 1984.

Methods

We analyzed data from the Australia and New Zealand Islet and Pancreas Transplant Registry, 1984 to 2014. We investigated the variation of donor characteristics of sex, age, body mass index, smoking status, blood group, multiple organ donation, cytomegalovirus status, terminal creatinine, hypertension, and cause of death for pancreas transplantation over time. We used χ² test (Fisher test when necessary) or analysis of variance to test difference for categorical or continuous characteristics, respectively.

Results

There were 628 pancreas donors from 1984 to 2014. Donor body mass index (from 21.9 to 24.0, P < 0.001) and age (from 23.9 to 28.5, P = 0.02) have both increased while terminal creatinine has decreased (86.3 to 73.3, P = 0.01) from 1995 to 2014. In the meantime, the proportions of donors with hypertension (from 19% to 1%, P < 0.001) and who were smokers (from 54% to 15%, P < 0.001) have decreased. Profile of cause of donor death has also changed over time (P = 0.06) with increase in cerebral hypoxia/ischemia (from 3% to 17%) and reductions in intracranial hemorrhage (27% to 13%).

Conclusions

Many donor characteristics have changed over time. The most significant changes appear to reflect changes in the general population, rather than changes in donor selection.

Pancreas Transplantation: An Alarming Crisis in Confidence

In the past decade, the annual number of pancreas transplantations performed in the United States has steadily declined. From 2004 to 2011, the overall number of simultaneous pancreas-kidney (SPK) transplantations in the United States declined by 10%, whereas the decreases in pancreas after kidney (PAK) and pancreas transplant alone (PTA) procedures were 55% and 34%, respectively. Paradoxically, this has occurred in the setting of improvements in graft and patient survival outcomes and transplanting higher-risk patients. Only 11 centers in the United States currently perform ≥20 pancreas transplantations per year, and most centers perform <5 pancreas transplantations annually; many do not perform PAKs or PTAs. This national trend in decreasing numbers of pancreas transplantations is related to a number of factors including lack of a primary referral source, improvements in diabetes care and management, changing donor and recipient considerations, inadequate training opportunities, and increasing risk aversion because of regulatory scrutiny. A national initiative is needed to "reinvigorate" SPK and PAK procedures as preferred transplantation options for appropriately selected uremic patients taking insulin regardless of C-peptide levels or "type" of diabetes. Moreover, many patients may benefit from PTAs because all categories of pancreas transplantation are not only life enhancing but also life extending procedures.

Type 1 Diabetes and Dysfunctional Intestinal Homeostasis

Despite the relatively high frequency of gastrointestinal (GI) disorders in individuals with type 1 diabetes (T1D), termed diabetic enteropathy (DE), the pathogenic mechanisms of these disorders remain to be elucidated. While previous studies have assumed that DE is a manifestation of diabetic autonomic neuropathy, other contributing factors such as enteric hormones, inflammation, and microbiota were later recognized. More recently, the emerging role of intestinal stem cells (ISCs) in several GI diseases has led to a new understanding of DE. Given the absence of diagnostic methods and the lack of broadly efficacious therapeutic remedies in DE, targeting factors and pathways that control ISC homeostasis and are dysfunctional in DE may represent a new path for the detection and cure of DE.

Pancreatic retransplantation is associated with poor allograft survival: an update of the United Network for Organ Sharing database

The aim of the study was to assess outcomes of pancreas retransplantation versus primary pancreas transplantation.

METHODS

Data from the United Network for Organ Sharing database on all adult (age, ≥18 years) subjects who received pancreas and kidney-pancreas transplants between 1996 and 2012 were analyzed (n = 20,854). The subjects were analyzed in the following 2 groups: retransplant (n = 1149) and primary transplant (n = 19,705).

RESULTS

Kaplan-Meier analysis demonstrated significantly different patient survival (P < 0.0001) and death-censored graft survival (P < 0.0001) between the primary transplant versus retransplant subjects. Allograft survival was significantly poorer in the retransplantation group. Patient survival was greater in the retransplant group.

CONCLUSIONS

The results of our study differ from previous studies, which showed similar allograft survival in primary and secondary pancreas transplants. Further studies may elucidate specific patients who will benefit from retransplantation. At the present time, it would appear that pancreas retransplantation is associated with poor graft survival and that retransplantation should not be considered for all patients with primary pancreatic allograft failure.

Pancreas transplantation in C-peptide positive patients: does "type" of diabetes really matter?

BACKGROUND

In the past, type 2 (C-peptide positive) diabetes mellitus (DM) was a contraindication for simultaneous pancreas-kidney transplantation (SPKT).

STUDY DESIGN

We retrospectively analyzed outcomes in SPKT recipients according to pretransplantation C-peptide levels ≥ 2.0 ng/mL or < 2.0 ng/mL.

RESULTS

From November 2001 to March 2013, we performed 162 SPKTs including 30 (18.5%) in patients with C-peptide levels ≥ 2.0 ng/mL pretransplantation (C-peptide positive group, range 2.1 to 12.4 ng/mL) and 132 in patients with absent or low C-peptide levels (<2.0 ng/mL, C-peptide "negative"). C-peptide positive patients were older at SPKT, had a later age of onset and shorter duration of pretransplantation DM, and more were African-American (all p < 0.05) compared with C-peptide negative patients. With a mean follow-up of 5.6 years, patient (80% vs 82.6%), kidney graft (63.3% vs 68.9%), and pancreas graft survivals (50% vs 62.1%, all p = NS) rates were comparable in C-peptide positive and negative patients, respectively. At latest follow-up, there were no differences in acute rejection episodes, surgical complications, major infections, readmissions, hemoglobin A1c levels, serum creatinine, and estimated glomerular filtration rate levels between the 2 groups. C-peptide levels were higher (mean 5.0 vs 2.6 ng/mL, p < 0.05) and post-transplant weight gain (≥ 5 kg) was more common (57% vs 33%, p = 0.004) in the C-peptide positive group. Survival outcomes in C-peptide positive (n = 14) vs C-peptide negative (n = 22) African-American patients were similar, as were outcomes in C-peptide positive patients with a body mass index < or ≥ 28 kg/m(2).

CONCLUSIONS

Patients with higher pretransplantion C-peptide levels appear to have a type 2 DM phenotype compared to insulinopenic patients undergoing SPKT. However, survival and functional outcomes were similar, suggesting that pretransplantation C-peptide levels should not be used exclusively to determine candidacy for SPKT.

Pancreas transplantation: The Wake Forest experience in the new millennium

AIM: To investigate the Wake Forest experience with pancreas transplantation in the new millennium with attention to surgical techniques and immunosuppression.

METHODS: A monocentric, retrospective review of outcomes in simultaneous kidney-pancreas transplant (SKPT) and solitary pancreas transplant (SPT) recipients was performed. All patients underwent pancreas transplantation as intent-to-treat with portal venous and enteric exocrine drainage and received depleting antibody induction; maintenance therapy included tapered steroids or early steroid elimination with mycophenolate and tacrolimus. Recipient selection was based on clinical judgment whether or not the patient exhibited measureable levels of C-peptide.

RESULTS: Over an 11.25 year period, 202 pancreas transplants were performed in 192 patients including 162 SKPTs and 40 SPTs. A total of 186 (92%) were primary and 16 (8%) pancreas retransplants; portal-enteric drainage was performed in 179 cases. A total of 39 pancreas transplants were performed in African American (AA) patients; of the 162 SKPTs, 30 were performed in patients with pretransplant C-peptide levels > 2.0 ng/mL. In addition, from 2005-2008, 46 SKPT patients were enrolled in a prospective study of single dose alemtuzumab vs 3-5 doses of rabbit anti-thymocyte globulin induction therapy. With a mean follow-up of 5.7 in SKPT vs 7.7 years in SPT recipients, overall patient (86% SKPT vs 87% SPT) and kidney (74% SKPT vs 80% SPT) graft survival rates as well as insulin-free rates (both 65%) were similar (P = NS). Although mortality rates were nearly identical in SKPT compared to SPT recipients, patterns and timing of death were different as no early mortality occurred in SPT recipients whereas the rates of mortality following SKPT were 4%, 9% and 12%, at 1-, 3- and 5-years follow-up, respectively (P < 0.05). The primary cause of graft loss in SKPT recipients was death with a functioning graft whereas the major cause of graft loss following SPT was acute and chronic rejection. The overall incidence of acute rejection was 29% in SKPT and 27.5% in SPT recipients (P = NS). Lower rates of acute rejection and major infection were evidenced in SKPT patients receiving alemtuzumab induction therapy. Comparable kidney and pancreas graft survival rates were observed in AA and non-AA recipients despite a higher prevalence of a “type 2 diabetes” phenotype in AA. Results comparable to those achieved in insulinopenic diabetics were found in the transplantation of type 2 diabetics with detectable C-peptide levels.

CONCLUSION: In the new millennium, acceptable medium-term outcomes can be achieved in SKPT and SPTs as nearly 2/3rds of patients are insulin independent following pancreas transplantation.

Predictors of non-transplantation of adult donor organs--an observational study using routine data from Eurotransplant

BACKGROUND

The majority of pancreases, offered in allocation, are not transplanted. This pancreas under-utilisation is a phenomenon observed in all transplant systems in North-America and Europe. It was the aim of this study to analyse factors predictive of pancreas non-transplantation in Germany.

METHODS

Routine Eurotransplant data of 3,666 deceased German donors (from 2002-2011) were used for multivariate modelling. Socio-demographic and medical factors were considered as independent variables in logistic regression models with non-transplantation as dependent variable.

RESULTS

Male gender, advanced age, overweight/obesity, long ICU stay, a history of smoking, non-traumatic brain death, elevated levels of sodium, serum glucose, lipase/amylase and the liver not being considered for procurement were significant independent predictors of non-transplantation.

CONCLUSION

In line with previous research, advanced age, high BMI, long ICU stay and the liver not being considered for procurement were the strongest predictors of pancreas non-transplantation in Germany. About three quarters of the variance remained unexplained, suggesting that factors not assessed or unknown may play a decisive role.

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.

Single-center experience using organs after rescue allocation for pancreas transplant in the eurotransplant region

OBJECTIVES

Because of the shortage of available organs for transplants, graft allocation polices have been modified recently. This report deals with the effect of using organs after rescue allocation for pancreas transplant in a single center in the Eurotransplant Region to possibly expand the donor pool.

MATERIALS AND METHODS

A retrospective analysis was performed. Between 2007 and 2010, thirty-one pancreas transplants were performed at the University Hospital of Leipzig, in Leipzig, Germany. Among these, 7 cases used rescue organs. These organs had been officially offered to, but rejected by, at least 3 consecutive transplant centers. Donor/recipient and clinical/laboratory transplant/posttransplant outcomes from patients receiving rescue organs were collected and were compared with organs from conventional donors.

RESULTS

Mean donor age was greater in the rescue organ group than in the conventional donor group (28.3 ± 10.7 y vs 23.0 ± 12.5 y). During follow-up (2.3 ± 0.6 y rescue organ group vs 3.9 ± 1.2 y conventional donor group), patient, kidney, and pancreas graft survival rates were 85% in all 3 categories in the rescue organ group, whereas outcomes for conventional donors were 88%, 85%, and 83%. Incidences of pancreatic graft thrombosis, delayed graft function, acute and late rejection episodes (eg, perioperative complications) were comparable between groups. No differences existed between mean serum urea levels and mean HbA1c levels between groups 2 years after transplant. Whereas 2 years after surgery, mean serum creatinine levels (rescue organ group, 78.8 ± 21.0 μmol/L vs 114.3 ± 28.4 μmol/L in the conventional donor group) showed significant differences between groups.

CONCLUSIONS

Results are promising. Further pro-spective studies are warranted to evaluate routine transplant of organs after rescue allocation.

Intercellular adhesion molecular-1, Fas, and Fas ligand as diagnostic biomarkers for acute allograft rejection of pancreaticoduodenal transplantation in pigs

BACKGROUND

The early diagnosis of pancreas allograft dysfunction is crucial for the management and long-term survival of transplanted pancreases. We investigated whether intercellular adhesion molecular-1 (ICAM-1), Fas, and Fas ligand (FasL) can be used as novel biomarkers of acute pancreaticoduodenal allograft dysfunction in pigs.

METHODS

Forty outbred landraces were randomly divided into three groups. In the control group (8 pigs), a sham operation was performed but no drugs were administered. In groups 1 and 2 (8 pairs each), pancreaticoduodenal transplantation was performed, with the latter administered immunosuppressive drugs and the former not administered drugs. The expression of ICAM-1, Fas, and FasL mRNA in the peripheral vein blood was assessed by flow cytometry and RT-PCR, pre-transplant and on days 1, 3, 5, and 7 after transplantation. Simultaneously, the levels of glucose, insulin, and glucagon in the serum of the recipients were evaluated. The allograft pancreas tissue was obtained to assess the pathological damage and the expression of Fas and FasL by immunohistochemistry.

RESULTS

On the first 7 days after transplantation, ICAM-1, Fas, and FasL mRNA expression in the blood leukocytes of the recipient increased significantly in groups 1 and 2 compared with the control group (P < 0.01). However, the levels in group 2 were significantly lower than those in group 1 (P < 0.05). Interestingly, the FasL expression increased but the Fas expression decreased gradually in the graft pancreas tissue during the first week after transplantation in both groups 1 and 2 compared with the control group (P < 0.05). The levels of serous glucose, insulin, and glucagon in groups 1 and 2 obviously changed on day 1 after transplantation but returned to normal on day 2. The recipient's pancreas pathological sections did not exhibit any rejection changes on days 1 and 3 after transplantation but showed rejection damage on days 5 and 7.

CONCLUSION

ICAM-1, Fas, and FasL were found to be sensitive biomarkers of acute pancreas allograft dysfunction after pancreaticoduodenal transplantation in pigs, and their monitoring could be used to evaluate the effectiveness of the immunosuppression therapy.

Pancreas transplantation with portal venous drainage with an emphasis on technical aspects

Advances in surgical techniques and clinical immunosuppression have led to improving results in vascularized pancreas transplantation. Most pancreas transplants are performed with enteric exocrine drainage and systemic venous delivery of insulin (systemic-enteric technique) although bladder drainage (systemic-bladder technique) remains a viable option. To improve the physiology of pancreas transplantation, an innovative technique of portal venous delivery of insulin and enteric drainage of the exocrine secretions (portal-enteric technique) was developed and refined over the past 27 yr. However, the potential of portal-enteric pancreas transplantation has never been fully realized as it is currently performed in only 18% of simultaneous pancreas-kidney/sequential pancreas after kidney and 10% of pancreas-alone transplants with enteric drainage. A number of studies have demonstrated no major or consistent differences in outcomes for bladder-drained or enteric-drained pancreas transplants with either portal or systemic venous drainage although some studies suggest purported metabolic and immunologic advantages associated with portal venous delivery of insulin. The purpose of this study is to review the existing literature on portal-enteric pancreas transplantation with an emphasis on surgical aspects and technical modifications/nuances that have been introduced with time and experience.

A composite risk model for predicting technical failure in pancreas transplantation

Technical failure (TF) continues to have a significant impact on the success of pancreas transplantation. We assessed risk factors for TF in 1115 pancreas transplants performed at a single center between 1998 and 2011. The overall TF rate was 10.2%. In a multivariable model, donor BMI ≥ 30 (HR 1.87, p = 0.005), donor Cr ≥ 2.5 (HR 3.16, p = 0.007), donor age >50 (HR 1.73, p = 0.082) and preservation time >20 h (HR 2.17, p < 0.001) were associated with TF. Bladder drainage of exocrine secretions was protective (HR 0.54, p = 0.002). We incorporated these factors in a Composite Risk Model. In this model the presence of one risk factor did not significantly increase risk of TF (HR 1.35, p = 0.346). Two risk factors in combination increased risk greater than threefold (HR 3.65, p < 0.001) and three risk factors increased risk greater than sevenfold (HR 7.66, p = <0.001). The analysis also identified many factors that were not predictive of TF, including previous transplants, immunosuppressive agent selection, and almost all recipient demographic parameters. While the model suggests that two or more risk factors predict TF, strategies to reduce preservation time may mitigate some of this risk.

Expanding the donor pool in pancreas transplantation

PURPOSE OF REVIEW

The current era of organ shortage has necessitated expansion of the currently available organ donor pool, to increase the number of pancreases available for transplant. This review summarizes the cumulative efforts of various centers in making this possible.

RECENT FINDINGS

Various centers are consistently reporting their experience with marginal donors; recent additions to the cohort have been increase in pancreases from donors after cardiac death (controlled and uncontrolled), update on long-term outcomes of live pancreas donors, as well as efforts at objectively assessing donor risk.

SUMMARY

It has become important for the transplanting surgeon to make difficult decisions on organ suitability and appropriateness depending upon the recipient's status. Further more, limiting further damage to these vulnerable grafts is important in improving utilization as well as successful transplantation.

Donor risk factors, retrieval technique, preservation and ischemia/reperfusion injury in pancreas transplantation

PURPOSE OF REVIEW

Pancreas transplantation is still hampered by a high incidence of early graft loss, and organ quality concerns result in high nonrecovery/discard rates. Demographic donor characteristics, surgical retrieval strategy, preservation fluid and ischemia time are crucial factors in the process of organ selection and are discussed in this review.

RECENT FINDINGS

The donor shortage is driving an increasing utilization of nonideal organs which would previously have been identified as unsuitable. Recent literature suggests that organs from extended criteria donors - older (>45 years), BMI >30  kg/m(2), and donation after cardiac death (DCD) - can achieve the same graft and patient survival as those from standard criteria donors, with the proviso that the accumulation of risk factors and long ischemic times should be avoided. Visual assessment of the pancreas is advisable before declining/accepting a pancreas. University of Wisconsin represents the gold standard solution; however, histidine-tryptophan-ketoglutarate and Celsior result in equal outcomes if cold ischemia time (CIT) is less than 12  h. Currently in pancreas transplantation, there is no proven effective ischemia/reperfusion injury prophylaxis than trying to keep CIT as short as possible.

SUMMARY

Demographic risk factors, inspection of the pancreas by an experienced surgeon and predicted CIT are crucial factors in deciding whether to accept a pancreas for transplantation. However, there is a need for an improved evidence base to determine where to set the 'cut-off' for unsuitable pancreatic grafts.

Long-term outcome after pancreas transplantation

PURPOSE OF REVIEW

Pancreas transplantation provides the only proven method to restore long-term normoglycemia in patients with insulin-dependent diabetes mellitus. Although many studies describe the very important risk factors for short-term survival of a pancreas transplant, there is not a lot of information available about factors that distinguish short-term from long-term graft function.

RECENT FINDINGS

The analysis of 18,159 pancreas transplants from the International Pancreas Transplant Registry, performed from 25 July 1978 to 31 December 2005, showed an improvement not only in short-term but also in long-term graft function. Most recent 5-year, 10-year and 20-year graft function for transplants with the appropriate follow-up time showed 80, 68 and 45%, respectively, for simultaneous pancreas/kidney transplants; 62, 46 and 16%, respectively, for pancreas after kidney; and 59, 39 and 12%, respectively, for pancreas transplants alone. Important factors influencing long-term function were factors that described the quality of the deceased donor. Pancreas transplants in younger or African-American recipients showed a higher risk of graft failure. Anti-T-cell induction therapy had a significant impact on long-term survival in solitary transplants.

SUMMARY

With a careful donor selection, not only short-term but also long-term pancreas graft function and, therefore, good metabolic control can be achieved for the diabetic patient.