Quality assessment of donor liver procurement surgery using an unadjusted CUSUM prediction model. A practical nationwide evaluation.

BACKGROUND: The aim of this study was to analyze the value of the unadjusted CUSUM graph of liver surgical injury and discard rates in organ procurement in the Netherlands. METHODS: Unadjusted CUSUM graphs were plotted for surgical injury (C event) and discard rate (C2 event) from procured livers accepted for transplantation for each local procurement team compared with the total national cohort. The average incidence for each outcome was used as benchmark based on procurement quality forms (Sep 2010-Oct 2018). The data from the five Dutch procuring teams were blind-coded. RESULTS: The C and C2 event rate were 17% and 1.9%, respectively (n = 1265). A total of 12 CUSUM charts were plotted for the national cohort and the five local teams. National CUSUM charts showed an overlapping "alarm signal." This overlapping signal for both C and C2, albeit a different time period, was only found in one local team. The other CUSUM alarm signal went off for two separate local teams, but only for C events or C2 events respectively, and at different points in time. The other remaining CUSUM charts showed no alarm signaling. CONCLUSION: The unadjusted CUSUM chart is a simple and effective monitoring tool in following performance quality of organ procurement for liver transplantation. Both national and local recorded CUSUMs are useful to see the implication of national and local effects on organ procurement injury. Both procurement injury and organ discard are equally important in this analysis and need to be separately CUSUM charted.

Performance of an easy-to-use prediction model for renal patient survival: an external validation study using data from the ERA-EDTA Registry.

Background: An easy-to-use prediction model for long-term renal patient survival based on only four predictors [age, primary renal disease, sex and therapy at 90 days after the start of renal replacement therapy (RRT)] has been developed in The Netherlands. To assess the usability of this model for use in Europe, we externally validated the model in 10 European countries. Methods: Data from the European Renal Association-European Dialysis and Transplant Association (ERA-EDTA) Registry were used. Ten countries that reported individual patient data to the registry on patients starting RRT in the period 1995-2005 were included. Patients <16 years of age and/or with missing predictor variable data were excluded. The external validation of the prediction model was evaluated for the 10- (primary endpoint), 5- and 3-year survival predictions by assessing the calibration and discrimination outcomes. Results: We used a data set of 136 304 patients from 10 countries. The calibration in the large and calibration plots for 10 deciles of predicted survival probabilities showed average differences of 1.5, 3.2 and 3.4% in observed versus predicted 10-, 5- and 3-year survival, with some small variation on the country level. The concordance index, indicating the discriminatory power of the model, was 0.71 in the complete ERA-EDTA Registry cohort and varied according to country level between 0.70 and 0.75. Conclusions: A prediction model for long-term renal patient survival developed in a single country, based on only four easily available variables, has a comparably adequate performance in a wide range of other European countries.

Stretching the Limits of Renal Transplantation in Elderly Recipients of Grafts from Elderly Deceased Donors.

An increasing number of elderly patients (≥65 years) receive a donor kidney from elderly donors after brain death (DBD) or after circulatory death (DCD). These organs are allocated within the Eurotransplant Senior Program, but outcomes must be evaluated. From the Dutch Organ Transplantation Registry, we selected 3597 recipients (≥18 years) who received a first DBD or DCD kidney during 2002-2012, and categorized them as young or elderly recipients receiving a graft from either a young or elderly donor, stratified by donor type. In multiple logistic regression analysis, elderly recipients of elderly DCD kidneys experienced more delayed graft function and acute rejection than did elderly recipients of young DBD kidneys (odds ratios 10.43 [95% confidence interval (95% CI), 5.75 to 18.91] and 2.78 [95% CI, 1.35 to 5.73], respectively). In Cox regression analysis, elderly recipients of elderly DCD kidneys had a 5-year mortality risk higher than that of elderly recipients of young DBD kidneys (hazard ratio, 1.86; 95% CI, 1.15 to 3.02). Elderly recipients of elderly kidneys had a 5-year mortality rate comparable to that of waitlisted elderly patients remaining on dialysis. Among elderly recipients, 63.8% of those who received elderly DCD kidneys, 45.5% of those who received elderly DBD kidneys, and approximately 26% of those who received young DBD or DCD kidneys had an eGFR<30 ml/min per 1.73 m2 (including primary nonfunction) after 1 year. In conclusion, improving donor selection and preservation is warranted if the allocation of elderly DCD grafts to elderly recipients is to be expanded.

Increased risk of graft failure and mortality in Dutch recipients receiving an expanded criteria donor kidney transplant.

Survival of expanded criteria donor (ECD) kidneys and their recipients has not been thoroughly evaluated in Europe. Therefore, we compared the outcome of ECD and non-ECD kidney transplantations in a Dutch cohort, stratifying by age and diabetes. In all first Dutch kidney transplants in recipients ≥18 years between 1995 and 2005, both relative risks (hazard ratios, HR) and adjusted absolute risk differences (RD) for ECD kidney transplantation were analysed. In 3062 transplantations [recipient age 49.0 (12.8) years; 20% ECD], ECD kidney transplantation was associated with graft failure including death [HR 1.62 (1.44-1.82)]. The adjusted HR was lower in recipients ≥60 years of age [1.32 (1.07-1.63)] than in recipients 40-59 years [1.71 (1.44-2.02) P = 0.12 for comparison with ≥60 years] and recipients 18-39 years [1.92 (1.42-2.62) P = 0.03 for comparison with ≥60 years]. RDs showed a similar pattern. In diabetics, the risks for graft failure and death were higher than in the nondiabetics. ECD kidney grafts have a poorer prognosis than non-ECD grafts, especially in younger recipients (<60 years), and diabetic recipients. Further studies and ethical discussions should reveal whether ECD kidneys should preferentially be allocated to specific subgroups, such as elderly and nondiabetic individuals.

Trends in dialysis modality choice and related patient survival in the ERA-EDTA Registry over a 20-year period.

BACKGROUND: Although previous studies suggest similar patient survival for peritoneal dialysis (PD) and haemodialysis (HD), PD use has decreased worldwide. We aimed to study trends in the choice of first dialysis modality and relate these to variation in patient and technique survival and kidney transplant rates in Europe over the last 20 years. METHODS: We used data from 196 076 patients within the European Renal Association-European Dialysis and Transplant Association (ERA-EDTA) Registry who started renal replacement therapy (RRT) between 1993 and 2012. Trends in the incidence rate and prevalence on Day 91 after commencing RRT were quantified with Joinpoint regression. Crude and adjusted hazard ratios (HRs) for 5-year dialysis patient and technique survival were calculated using Cox regression. Analyses were repeated using propensity score matching to control for confounding by indication. RESULTS: PD prevalence dropped since 2007 and HD prevalence stabilized since 2009. Incidence rates of PD and HD decreased from 2000 and 2009, respectively, while the incidence of kidney transplantation increased from 1993 onwards. Similar 5-year patient survival for PD versus HD patients was found in 1993-97 [adjusted HR: 1.02, 95% confidence interval (95% CI): 0.98-1.06], while survival was higher for PD patients in 2003-07 (HR: 0.91, 95% CI: 0.88-0.95). Both PD (HR: 0.95, 95% CI: 0.91-1.00) and HD technique survival (HR: 0.93, 95% CI: 0.87-0.99) improved in 2003-07 compared with 1993-97. CONCLUSIONS: Although initiating RRT on PD was associated with favourable patient survival when compared with starting on HD treatment, PD was often not selected as initial dialysis modality. Over time, we observed a significant decline in PD use and a stabilization in HD use. These observations were explained by the lower incidence rate of PD and HD and the increase in pre-emptive transplantation.

Improved Mortality Prediction in Dialysis Patients Using Specific Clinical and Laboratory Data.

BACKGROUND: Risk prediction models can be used to inform patients undergoing renal replacement therapy about their survival chances. Easily available predictors such as registry data are most convenient, but their predictive value may be limited. We aimed to improve a simple prediction model based on registry data by incrementally adding sets of clinical and laboratory variables. METHODS: Our data set includes 1,835 Dutch patients from the Netherlands Cooperative Study on the Adequacy of Dialysis. The potential survival predictors were categorized on availability. The first category includes easily available clinical data. The second set includes laboratory values like albumin. The most laborious category contains glomerular filtration rate (GFR) and Kt/V. Missing values were substituted using multiple imputation. Within 1,225 patients, we recalibrated the registry model and subsequently added parameter sets using multivariate Cox regression analyses with backward selection. On the other 610 patients, calibration and discrimination (C-index, integrated discrimination improvement (IDI) index and net reclassification improvement (NRI) index) were assessed for all models. RESULTS: The recalibrated registry model showed adequate calibration and discrimination (C-index=0.724). Adding easily available parameters resulted in a model with 10 predictors, with similar calibration and improved discrimination (C-index=0.784). The IDI and NRI indices confirmed this, especially for short-term survival. Adding laboratory values resulted in an alternative model with similar discrimination (C-index=0.788), and only the NRI index showed minor improvement. Adding GFR and Kt/V as candidate predictors did not result in a different model. CONCLUSION: A simple model based on registry data was enhanced by adding easily available clinical parameters.

Certification Training and Liver Transplant Experience Improves Liver Procurement Outcomes: The Dutch Approach.

BACKGROUND: This study investigates the impact of certification training and liver transplant experience on procurement outcomes of deceased donor liver procurement in the Netherlands. METHODS: Three groups (trainee, certified, and master) were formed, with further subdivision based on liver transplant experience. Three key outcomes-surgical injury, graft discard after injury, and donor hepatectomy duration-were analyzed. RESULTS: There were no significant differences in surgical graft injury in the three groups (trainee, 16.9%; certified, 14.8%; master, 18.2%; P  = 0.357; 2011 to 2018). The only predictor for surgical graft injury was donation after circulatory death (odds ratio [OR], 1.49; 95% confidence interval [CI], 1.10-2.02). Of the three groups, the master group had the highest discard rate after surgical injury (trainee, 0%; certified, 1.3%; master, 2.8%; P  = 0.013). Master group without liver transplant experience (OR, 3.16; 95% CI, 1.21-8.27) and male donor sex (OR, 3.58; 95% CI, 1.32-9.73) were independent risk factors for discarding livers after surgical injury. Independent predictors for shorter hepatectomy durations included donors older than 50 years (coefficient [Coeff], -7.04; 95% CI, -8.03 to -3.29; P  < 0.001), and master group (Coeff, -9.84; 95% CI, -14.37 to -5.31; P  < 0.001) and certified group with liver transplant experience (Coeff, -6.54; 95% CI, -10.83 to -2.26; P  = 0.003). On the other hand, master group without liver transplant experience (Coeff, 5.00; 95% CI, 1.03-8.96; P  = 0.014) and donation after circulatory death (Coeff, 10.81; 95% CI, 8.32-13.3; P  < 0.001) were associated with longer hepatectomy durations. CONCLUSIONS: Training and certification in abdominal organ procurement surgery were associated with a reduced discard rate for surgical injured livers and shorter hepatectomy times. The contrast between master group with and without liver transplant experience underscores the need for specialized training in this field.

Survival prognosis after the start of a renal replacement therapy in the Netherlands: a retrospective cohort study.

BACKGROUND: There is no single model available to predict the long term survival for patients starting renal replacement therapy (RRT). The available models either predict survival on dialysis until transplantation, survival on the transplant waiting list, or survival after transplantation. The aim of this study was to develop a model that includes dialysis survival and survival after an eventual transplantation. METHODS: From the Dutch renal replacement registry, patients of 16 years of age or older were included if they started RRT between 1995 and 2005, still underwent RRT at baseline (90 days after the start of RRT) and were not registered at a non-renal organ transplant waiting list (N = 13868). A prediction model of 10-year patient survival after baseline was developed through multivariate Cox regression analysis, in one half of the research group. Age at start, sex, primary renal disease (PRD) and therapy at baseline were included as possible predictors. A sensitivity analysis has been performed to determine whether listing on the transplant waiting list should be added. The predictive performance of the model was internally validated. Calibration and discrimination were computed in the other half of the research group. Another sensitivity analysis was to assess whether the outcomes differed if the model was developed and tested in two geographical regions, which were less similar than the original development and validation group. No external validation has been performed. RESULTS: Survival probabilities were influenced by age, sex, PRD and therapy at baseline (p < 0.001). The calibration and discrimination both showed very reasonable results for the prediction model (C-index = 0.720 and calibration slope for the prognostic index = 1.025, for the 10 year survival). Adding registration on the waiting list for renal transplantation as a predictor did not improve the discriminative power of the model and was therefore not included in the model. CONCLUSIONS: With the presented prediction model, it is possible to give a reasonably accurate estimation on the survival chances of patients who start with RRT, using a limited set of easily available data.

Waiting List Dynamics and Lung Transplantation Outcomes After Introduction of the Lung Allocation Score in The Netherlands.

The Netherlands was the third country to adopt the lung allocation score (LAS) for national allocation of donor lungs in April 2014. Evaluations of the introduction of the LAS in the United States and Germany showed mainly beneficial effects, including increased survival after transplantation. METHODS: Data for transplant candidates from 2010 to 2019 were retrieved from the Dutch Transplant Foundation database. Diagnosis categories and outcomes were compared between the periods before and after the introduction of the LAS. Time-dependent Cox regression and Fine-Gray analyses were performed to compare the chance for transplantation before and after introduction of the LAS. RESULTS: The cohort comprised 1276 patients. After introduction of the LAS, the annual number of transplantations and waiting list mortality did not change. The proportion of patients on the waiting list and transplanted patients with pulmonary fibrosis increased (25%-37%, P < 0.001; 22%-39%, P < 0.001). The chance of transplantation increased significantly for patients with pulmonary fibrosis after introduction of the LAS (hazard ratio 1.9 [95% confidence interval 1.4-2.9]). Patients who died on the waiting list had an increased LAS compared to the time of placement on the waiting list, reflecting clinical deterioration. This was not the case in patients with chronic obstructive pulmonary disease (P < 0.001). Overall survival was similar after introduction of the LAS (5-y survival 68%, compared to 74% [P = 0.171]). CONCLUSIONS: After the introduction of the LAS in The Netherlands, an increased proportion of transplantations was performed for patients with pulmonary fibrosis. Overall survival after transplantation did not change.

Significant Decreasing Incidence of Encapsulating Peritoneal Sclerosis in the Dutch Population of Peritoneal Dialysis Patients.

The Dutch Encapsulating Peritoneal Sclerosis (EPS) Registry was started in 2009. Cases were identified by contacting all Dutch nephrologists twice yearly. The predefined criteria for EPS allowed for inclusion of patients with diagnosed and suspected EPS. Cases registered between January 2009 and January 2015 were analyzed with follow-up until September 2015. Fifty-three EPS cases were identified, of which 28.3% were post-transplantation EPS cases. Fourteen patients were initially categorized as suspected EPS, of whom 13 developed EPS. A remarkable 6-fold decrease in the yearly incidence of EPS was observed, from 0.85% in 2009 to 0.14% in 2014. This decrease could not be explained by a decrease in the number of PD patients or average duration of PD treatment in this period. Two-year survival of EPS patients was 52%. The use of tamoxifen and surgical interventions increased significantly over the years. Tamoxifen-treated cases showed a trend to better patient survival and post-transplantation EPS had a significantly favorable outcome. In conclusion, the incidence of EPS has declined significantly in the Netherlands from 2009 to 2014.

[Causes of decreased use of peritoneal dialysis as a kidney replacement therapy in the Netherlands]. / Oorzaken voor verminderd aandeel peritoneale dialyse als niervervangende behandeling in Nederland.

OBJECTIVE: To study the extent and causes of the declining use of peritoneal dialysis (PD) as kidney replacement therapy in patients with end-stage renal disease in the Netherlands. DESIGN: Retrospective cohort study. METHOD: The prevalence and incidence of various kidney replacement therapies in the Netherlands from 1995 to 2010 were analysed. Also the 5-year outflow of patients on PD or haemodialysis (HD) from 1995 to 2006 was analysed using the cumulative incidence competing risks method and Cox regression analysis. RESULTS: The absolute number of patients starting PD between 1995 and 2008 was stable at about 400 per year. There was a relative decline in the use of PD in the total dialysis population from 15% in 1995 to 8% in 2010. This decrease was seen in both large and small centres and was related to a relative increase in the numbers undergoing HD (67% before 2001, 74% in 2009), and kidney transplantation before dialysis (3% before 2002, 9% in 2009), as well as a decrease in change of therapy from HD to PD. The increased number starting on HD was associated with the growth of the incident patient group aged 65 years or older, most of whom (80-85%) underwent HD. Within the younger group (0-65 years) there was an increase in numbers on HD and in the number of pre-emptive transplantations. CONCLUSION: The decline in the prevalence of PD was partly explained by the relative increase in numbers starting HD, associated with an ageing patient population, fewer people changing from HD to PD therapy, and the increased number of kidney transplantations before dialysis in younger patients. The increasing prevalence of HD has been made possible by growth of the HD capacity.

Patient survival after the diagnosis of cancer in renal transplant recipients: a nested case-control study.

INTRODUCTION: Malignancy is a well-known complication after renal transplantation. We studied the influence of cancer on patient survival in the Dutch renal transplant population in a nested case-controlled analysis. METHODS: Between March 1966 and May 2008, 15,227 renal transplantations in 12,805 recipients were registered in the Netherlands Organ Transplant Registry database. Total follow-up was 89,651 person years. We performed an analysis of patient and graft survival both from the day of transplantation and the diagnosis of cancer in recipients with invasive cancer. Recipients without invasive cancer, matched for gender, age, and year of transplantation, served as a control group. For the survival analysis after the diagnosis of cancer, the matched control group consisted of patients with a functioning graft at the moment the index patient was diagnosed with cancer. RESULTS: Cancer had been registered in 908 (7.1%) patients, 630 (69%) of them died with functioning kidney, 510 (81%) because of their malignancy (at 8.2 years after transplantation, median). The median patient survival after transplantation was 11.9 vs. 16.8 years in the study and control group, respectively (P<0.001). The median patient and graft survival after the diagnosis of cancer was 2.1 vs. 8.3 (P<0.001) and 25 vs. 22.4 (P<0.001) years in the study and control group, respectively. CONCLUSION: Mortality because of cancer is observed at a significantly later time after transplantation compared with mortality because of the other main lethal complications. It significantly affects life expectancy and carries a poor prognosis with a limited survival after diagnosis.