Donor Risk Index Does Not Predict Graft Survival After Pancreas Transplantation in Brazil

Donor noradrenaline use is associated with better allograft survival in recipients of pancreas transplantation

INTRODUCTION

Outcomes following pancreas transplantation are suboptimal and better donor selection is required to improve this. Vasoactive drugs (VaD) are commonly used to correct the abnormal haemodynamics of organ donors in intensive care units. VaDs can differentially affect insulin secretion positively (dobutamine) or negatively (noradrenaline). The hypothesis was that some VaDs might induce beta-cell stress or rest and therefore impact pancreas transplant outcomes. The aim of the study was to assess relationships between VaD use and pancreas transplant graft survival.

METHODS

Data from the UK Transplant Registry on all pancreas transplants performed between 2004 and 2016 with complete follow-up data were included. Univariable- and multivariable-adjusted Cox regression analyses determined risks of graft failure associated with VaD use.

RESULTS

In 2,183 pancreas transplants, VaDs were used in the following numbers of donors: dobutamine 76 (3.5%), dopamine 84 (3.8%), adrenaline 161 (7.4%), noradrenaline 1,589 (72.8%) and vasopressin 1,219 (55.8%). In multivariable models, adjusted for covariates and the co-administration of other VaDs, noradrenaline use (vs non-use) was a strong predictor of better graft survival (hazard ratio [95% confidence interval] 0.77 [0.64-0.94], p = 0.01).

CONCLUSIONS

Noradrenaline use was associated with better graft survival in models adjusted for donor and recipient variables - this may be related to inhibition of pancreatic insulin secretion initiating pancreatic beta-cell 'rest'. Further research is required to replicate these findings and establish whether relationships are causal. Identification of alternative methods of inducing beta-cell rest could be valuable in improving graft outcomes.

Validating the US pancreas donor risk index in a Norwegian population, a retrospective observational study

OBJECTIVES

Despite advances in immunosuppression and surgical technique, pancreas transplantation is still associated with a significant graft loss rate. The Pancreas Donor Risk Index (PDRI) is a pre-transplant scoring tool derived from a US population. We sought to validate the PDRI in a Norwegian population.

METHODS

We retrospectively retrieved donor data for 344 pancreas transplants undertaken in Norway between 2000 and 2019, utilising the Scandiatransplant database, and matched these to the respective recipients. The PDRI score was calculated for each transplanted pancreas, these were then stratified into quintiles. The association between the PDRI quintiles and 1-year graft survival was calculated, and this was repeated for the different types of pancreas transplantation. The association between PDRI as a continuous variable, and graft survival was determined. Donor and recipient data were compared to the original US population.

RESULTS

The overall 1-year graft survival was 82.7%. There were no significant differences in survival between the different PDRI quintiles. When viewed as a continuous variable, increased PDRI score was not associated with decreased graft survival. Significant differences between the Norwegian and US populations were found.

CONCLUSIONS

When applied to a Norwegian population, the PDRI score was unable to predict 1-year graft survival.

Pancreas Donor Risk Index and Preprocurement Pancreas Suitability Score for Prediction of Pancreas Transplant Outcomes

OBJECTIVES

The Pancreas Donor Risk Index and Preprocurement Pancreas Suitability Score were designed to assist in the evaluation of pancreases for transplant. Preprocurement Pancreas Suitability Score <17 and PancreasDonor Risk Index ≤1.57 were deemed ideal.We aimed to determine the ability ofthese scores to predict pancreas transplant outcomes.

MATERIALS AND METHODS

The Pancreas Donor Risk Index and the Preprocurement Pancreas Suitability Score were retrospectively calculated from a prospectively maintained database of consecutive pancreas transplants performed during a 13-year period (December 2004 to November 2017). Outcomes measuredwere rejection rate, graft and patient survival, and duration of hospital stay.

RESULTS

Of 159 pancreas transplants (108 simultaneous pancreas and kidney transplants, 33 pancreas after kidney transplants, 18 pancreas-only transplants), full data were available for 155 (97%) to calculate Pancreas Donor Risk Indexes and 129 (81%) to calculate Preprocurement Pancreas Suitability Scores. Fortyseven patients (30%) experienced at least 1 episode of acute rejection. We calculated Pancreas Donor Risk Indexes for 155 patients, and 19 (23%) and 27 (38%) were in the ≤1.57 and >1.57 groups, respectively (P = .047). We calculated Preprocurement Pancreas Suitability Scores for 129 patients, and 12 (21%) and 27 (32%) were in the <17 and ≥17 groups, respectively (P = .202). Donor age and recipientfemale sex were the main predictors forrejection (binary logistic regression, P < .05). One-year graft survival rates were 95% and 81% forthe ≤1.57 and >1.57 PancreasDonor Risk Index groups,respectively, and 95% and 80% forthe <17 and ≥17 Preprocurement Pancreas Suitability Score groups, respectively (not significant).

CONCLUSIONS

Pancreas Donor Risk Index and Preprocurement Pancreas Suitability Score were not helpful to predict graft/patient survival in our population. A higher Pancreas Donor Risk Index was associated with higher risk of graft rejection. Further studies with larger cohorts are required.

Donor insulin therapy in intensive care predicts early outcomes after pancreas transplantation

AIMS/HYPOTHESIS

Approximately 50% of organ donors develop hyperglycaemia in intensive care, which is managed with insulin therapy. We aimed to determine the relationships between donor insulin use (DIU) and graft failure in pancreas transplantation.

METHODS

UK Transplant Registry organ donor data were linked with national data from the UK solid pancreas transplant programme. All pancreas transplants performed between 2004 and 2016 with complete follow-up data were included. Logistic regression models determined associations between DIU and causes of graft failure within 3 months. Area under the receiver operating characteristic curve (aROC) and net reclassification improvement (NRI) assessed the added value of DIU as a predictor of graft failure.

RESULTS

In 2168 pancreas transplant recipients, 1112 (51%) donors were insulin-treated. DIU was associated with a higher risk of graft loss from isolated islet failure: OR (95% CI), 1.79 (1.05, 3.07), p = 0.03, and this relationship was duration/dose dependent. DIU was also associated with a higher risk of graft loss from anastomotic leak (2.72 [1.07, 6.92], p = 0.04) and a lower risk of graft loss from thrombosis (0.62 [0.39, 0.96], p = 0.03), although duration/dose-dependent relationships were only identified in pancreas transplant alone/pancreas after kidney transplant recipients with grafts failing due to thrombosis (0.86 [0.74, 0.99], p = 0.03). The relationships between donor insulin characteristics and isolated islet failure remained significant after adjusting for potential confounders: DIU 1.75 (1.02, 2.99), p = 0.04; duration 1.08 (1.01, 1.16), p = 0.03. In multivariable analyses, donor insulin characteristics remained significant predictors of lower risk of graft thrombosis in pancreas transplant alone/pancreas after kidney transplant recipients: DIU, 0.34 (0.13, 0.90), p = 0.03; insulin duration/dose, 0.02 (0.001, 0.85), p = 0.04. When data on insulin were added to models predicting isolated islet failure, a significant improvement in discrimination and risk reclassification was observed in all models: no DIU aROC 0.56; DIU aROC 0.57, p = 0.86; NRI 0.28, p < 0.00001; insulin duration aROC 0.60, p = 0.47; NRI 0.35, p < 0.00001.

CONCLUSIONS/INTERPRETATION

DIU predicts graft survival in pancreas transplant recipients. This assessment could help improve donor selection and thereby improve patient and graft outcomes.

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.

Development and validation of a quantitative electron microscopy score to assess acute cellular stress in the human exocrine pancreas

The pancreas is particularly sensitive to acute cellular stress, but this has been difficult to evaluate using light microscopy. Pancreatic ischaemia associated with deceased organ donation negatively impacts whole‐organ and isolated‐islet transplantation outcomes. Post‐mortem changes have also hampered accurate interpretation of ante‐mortem pancreatic pathology. A rigorous histological scoring system accurately quantifying ischaemia is required to experimentally evaluate innovations in organ preservation and to increase rigour in clinical/research evaluation of underlying pancreatic pathology. We developed and validated an unbiased electron microscopy (EM) score of acute pancreatic exocrine cellular stress in deceased organ donor cohorts (development [n = 28] and validation [n = 16]). Standardised assessment led to clearly described numerical scores (0–3) for nuclear, mitochondrial and endoplasmic reticulum (ER) morphology and intracellular vacuolisation; with a maximum (worst) aggregate total score of 12. In the Validation cohort, a trend towards higher scores was observed for tail versus head regions (nucleus score following donation after brainstem death [DBD]: head 0.67 ± 0.19; tail 0.86 ± 0.11; p = 0.027) and donation after circulatory death (DCD) versus DBD (mitochondrial score: DCD (head + tail) 2.59 ± 0.16; DBD (head + tail) 2.38 ± 0.21; p = 0.004). Significant mitochondrial changes were seen ubiquitously even with short cold ischaemia, whereas nuclear and vacuolisation changes remained mild even after prolonged ischaemia. ER score correlated with cold ischaemia time (CIT) following DBD (pancreatic tail region: r = 0.796; p = 0.018). No relationships between CIT and EM scores were observed following DCD. In conclusion, we have developed and validated a novel EM score providing standardised quantitative assessment of subcellular ultrastructural morphology in pancreatic acinar cells. This provides a robust novel tool for gold standard measurement of acute cellular stress in studies evaluating surrogate measures of peri‐transplant ischaemia, organ preservation technologies and in samples obtained for detailed pathological examination of underlying pancreatic pathology.

The Role of Pre-Procurement Pancreas Suitability Score (P-PASS) and Pancreas Donor Risk Index (PDRI) in the Outcome of Simultaneous Pancreas and Kidney or Pancreas After Kidney Transplantation

Background

The pre-procurement pancreas suitability score (P-PASS) and the pancreas donor risk index (pDRI) are established predictive scores for graft survival and patient outcome following pancreatic transplantation. This retrospective study aimed to evaluate the predictive value of P-PASS and pDRI following simultaneous pancreas and kidney (SPK) transplantation, or pancreas after kidney (PAK) transplantation, and the clinical impact of donor-specific factors on the postoperative graft and recipient outcome at a single transplant center.

Material/Methods

The study included 105 patients who underwent SPK (n=104) or PAK (n=4) between 2000 and 2017. Donor-specific and recipient-specific parameters were recorded. Kaplan-Meier analysis and Cox regression analysis were used to assess the outcome after transplantation.

Results

Overall, the mean 1-year and 5-year pancreas graft survival and patient survival rates were 78.7% and 93.2%, and 76.9% and 90.0%, respectively. The postoperative outcome in patients with a P-PASS score of <17 was not significantly different when compared with patients with a score of ≥17. A P-PASS score of ≥17 was significantly associated with early pancreas graft loss (p=0.04). There was no significant difference in postoperative outcome between patients with high pDRI and low pDRI. Smoking of donor (p=0.046) was a risk factor and coronary heart disease of recipient (p=0.003) had a significant effect on survival of pancreas graft.

Conclusions

This study showed that P-PASS and pDRI were not reliable predictors of outcome after pancreas transplantation and that specific characteristics of the donor and recipient must be evaluated when predicting the outcome of pancreas transplantation.

Pancreas Donor Risk Index but Not Pre-Procurement Pancreas Allocation Suitability Score Predicts Pancreas Graft Survival: A Cohort Study from a Large German Pancreas Transplantation Center

Background

The pre-procurement pancreas allocation suitability score (P-PASS) was introduced to support clinical decision-making and ultimately expand the currently insufficient pancreas donor pool. The pancreas donor risk index (PDRI) can be used at the time of organ offering to predict one-year graft survival. Thus, this study aimed to analyze the validity of the PDRI and P-PASS in a large German transplant center.

Material/Methods

From 2002 to 2015, we performed 327 pancreas transplantations at our center. P-PASS and PDRI were calculated for 322 patients. To evaluate the pancreas graft survival, the patient cohort was divided into 2 P-PASS (<17, n=115 and ≥17, n=207) and 3 PDRI groups (<1, n=87; 1–1.5, n=133; and >1.5, n=102). Kaplan-Meier and Cox regression analyses were performed. We also examined differences regarding early pancreas graft failure for both scores using the chi-square test.

Results

The PDRI was associated with pancreas graft survival in the univariate analysis (p=0.023). In the multivariate analysis, a PDRI >1.5 was associated with significantly decreased graft survival (hazard ratio=1.792, 95% confidence interval=1.10–2.90, p=0.018). The P-PASS showed no significant association (p=0.081) with pancreas graft survival in the Kaplan-Meier survival analysis. There were significantly more early pancreas graft losses in the P-PASS ≥17 group (p=0.025).

Conclusions

Our results showed an association between P-PASS ≥17 and early pancreas graft failure. However, this does not apply to long-term pancreas graft survival; the PDRI proved to be a better tool for this, and PDRI values >1.5 were associated with significantly worse outcomes after pancreas transplantation.

Usefulness of Pancreas Donor Risk Index and Pre-Procurement Pancreas Allocation Suitability Score: Results of the Polish National Study

Background

Pre-procurement pancreas suitability score (P-PASS) and pancreas donor risk (PDRI) index are scoring systems believed to predict suitability of pancreatic grafts. Most European countries and the United States apply PDRI, while Poltransplant keeps using P-PASS: more than 16 points raises a red flag for graft use. Recent data discourage use of PDRI to predict pancreas graft survival. The aim of the present study was to assess PDRI and P-PASS as predictors of transplanted pancreas survival in a Polish population.

Material/Methods

From February 1998 to September 2015, 407 pancreas transplantations were performed in Poland: 370 (90.9%) simultaneous pancreas-kidney transplantation and 37 (9.1%) pancreas transplantation alone or pancreas after kidney. The endpoint was death-uncensored 12-month graft survival with satisfactory glycemic control without insulin.

Results

Average P-PASS was 15.9±2.66 and PDRI was 0.96±0.37. Recipients who survived 12 months with good graft function had an average P-PASS score of 15.7 and PDRI of 0.95. Recipients with death-uncensored graft loss had a mean P-PASS of 16.4 and PDRI of 0.99. Univariate analysis revealed donor age, body mass index (BMI), and P-PASS to be significant risk factors for 1-year pancreas graft survival.

Conclusions

P-PASS, but not PDRI, is a reliable tool to predict pancreas graft survival in the Polish population.

Techniques of pancreas graft salvage/indications for allograft pancreatectomy

PURPOSE OF REVIEW

Despite improvements in pancreas allograft outcome, graft complications remain a significant cause of morbidity and mortality. This review analyses the issues involved in the management of conditions that may require graft pancreatectomy, including the indications and techniques for graft salvage.

RECENT FINDINGS

With early recognition of graft complications, liberal use of radiological interventions, improved infection control, access to critical care and innovative surgical techniques, graft salvage is now feasible in many circumstances where graft pancreatectomy would previously have been necessary.

SUMMARY

The outcome of pancreas transplantation continues to improve with advances in the management of graft-threatening complications.

Validation of the Pancreatic Donor Risk Index in Simultaneous Pancreas-Kidney Transplantation Performed in Córdoba Hospital From 2000 to 2015

BACKGROUND

The Pancreatic Donor Risk Index (PDRI) was developed in 2010 in the United States to predict graft survival after pancreas transplantation, based on donor characteristics and logistical and technical conditions. The aim of the study was to validate the utility of PDRI as a pancreas allograft survival predictor in simultaneous pancreas-kidney transplantation (SPK) transplants performed in our hospital between 2000 and 2015.

METHODS

This retrospective analysis of 126 SPK transplants was performed by the same surgical team from the years 2000 to 2015. Donor variables that are integrated in the PDRI were calculated (age, sex, race, creatinine serum levels, body mass index, height, cold ischemia time, cause of death, type of pancreas transplant). Pancreatic graft survival at 1 and 5 years was calculated by use of the Kaplan-Meier test. Comparison of survival curves between PDRI risk quartiles was calculated by use of the log-rank test. Association between graft survival and variables integrating the PDRI was calculated by use of univariate Cox regression analysis.

RESULTS

Log-rank analysis found no statistically significant association between global graft survival and PDRI quartiles. Univariate Cox regression analysis showed a statistically significant association between graft survival and cold ischemia time (P < .05).

CONCLUSIONS

PDRI was not a useful tool to predict pancreatic graft outcomes in a Spanish reference population.