TRANSATLANTIC TRANSPLANTATION PROGRAM The prevalence of end-stage renal disease (ESRD) in the Dutch Antilles is among the highest in the world, estimated at approximately 285 cases/100,000 (Ajubi, unpublished). As a comparison, the Netherlands has a prevalence for ESRD of 102 of 100,000.1 The Amsterdam University Medical Center (UMC) together with the Eurotransplant Foundation began a unique transatlantic program in 1998, enabling Dutch Antillean ESRD patients to be on the Eurotransplant waiting list.2 INTERNATIONAL CORPORATION The collaboration with the Dutch Antilles was initiated by the St. Elisabeth Hospital in 1998, extended to the Dr. Horacio E. Oduber Hospital in 2003, the Fundashon Mariadal in 2010, and St Maarten Medical Center in 2014.3 This transatlantic program contains several unique features.4 Relevant aspects include, in case of a kidney offer, a guaranteed seat on the first flight of the Dutch Royal Airlines to Amsterdam, organ acceptance of brain dead donors (DBD), and preservation of donor kidneys by hypothermic machine perfusion (HMP). Candidates from the Dutch Antilles are evaluated and informed of organ offers by Amsterdam UMC nephrologists. HLA typing and antibody screening of blood samples are performed by the department of Immunogenetics of Sanquin Diagnostic Services (the Netherlands). All patients receive induction therapy with basiliximab with triple regimens maintenance therapy (mycophenolic acid, tacrolimus, and corticosteroids) as a standard treatment at Amsterdam UMC. CHALLENGES Cold Ischemia Time One of the biggest challenges of this program is the 7845-km distance between the Dutch Antilles and the Netherlands with a flying duration of approximately 9 h, plus a 20-min ride from Schiphol Airport to the Amsterdam UMC. Preparation of the recipient and availability of an operating room in the Amsterdam UMC can all together lead to prolonged cold ischemia time (CIT) of the donor kidney. CIT is defined as the time from cold flushing until the start of the transplant anastomosis in the recipient. Here, we report on the outcome of the Caribbean cohort focusing on the impact of prolonged CIT. Furthermore, we compare outcomes to a propensity-score matched cohort of transplant recipients in the Netherlands. Data were retrieved from the National Dutch Transplantation Database and local patient records, complying with the rules of the declaration of Helsinki. TRANSPLANT RATES AND OUTCOMES Ninety patients have been transplanted with a DBD donor kidney between 2007 and October 2018 and followed-up until November 2019. Median overall CIT was 25.7 h (IQR 22.6–33.9). Categorizing CIT into <24 h (n = 30%, 32%), 24 h–<34 h (n = 38%, 41%), and ≥34 h (n = 22%, 23%), we saw comparable baseline characteristics in all groups. Overall, we safely transplanted DBD donor kidneys with prolonged CIT to Dutch Antillean recipients. Figure 1 depicts death-censored graft survival (GS), graft survival, and patient survival per CIT category, with no statistically significant differences between CIT groups (P = 0.053; Figure 1A, P = 0.390, Figure 1B, P = 0.430; Figure 1C, respectively); 1- and 5-y survival rates, delayed graft function (DGF), primary nonfunction (PNF), rejection and causes of graft failure, and patient death are included in the Supplemental Information (SDC, https://links.lww.com/TP/C676).FIGURE 1.: A, Death-censored graft survival (GS) of Dutch Antillean recipients by CIT categories; <24 h (red), 24–<34 h (green), ≥34 h (blue). B, Graft survival of Dutch Antillean recipients by CIT categories; <24 h (red), 24–<34 h (green), ≥34 h (blue). C, Patient survival of Dutch Antillean recipients by cold ischemia time (CIT) categories; <24 h (red), 24–<34 h (green), ≥34 h (blue). All data show Kaplan–Meier analysis; comparisons between groups were not significantly different.After applying the propensity-score matching method (2:1 ratio, nearest neighbor, caliper 0.2), 96 Dutch patients could be matched to 57 patients of the Antillean cohort. DBD donor kidneys allocated to patients in the matched Dutch Amsterdam UMC cohort were preserved by cold static storage (CSS). Median CIT of the matched control AMC cohort was 15.7 h (IQR 11.6–19.8), and 25.0 h (IQR 22.0–31.7) for the Antillean cohort. Death-censored graft survival was comparable between recipients from the Dutch Antilles and the matched controls from the Netherlands (P = 0.216; Figure 2).FIGURE 2.: Death-censored graft survival (GS) of Dutch Antilles (blue) vs Dutch Amsterdam UMC, location AMC, propensity matched control cohort (red). Kaplan–Meier curves are shown; no significant differences were observed, calculated with Cox regression using a robust variance estimator and inclusion of propensity weights. To achieve balance on donor and recipient characteristics, we used a propensity-score matching method with caliper of 0.25 to greedy select Dutch recipients to the Antillean cohort in a 2:1 ratio (package Matchit). The matching variables were transplant date, brain-death donor type, donor age, recipient age, recipient BMI, recipient diabetes, recipient primary disease, and anastomosis time. Patient characteristics of the matched Dutch recipient, also treated in the Amsterdam UMC, location AMC, were extracted from the Dutch organ transplantation registry (NOTR). In the matched sample, death-censored GS was plotted with Kaplan–Meier, and differences tested with a Cox proportional hazards model using a robust variance estimator.DISCUSSION AND FUTURE PERSPECTIVES Here, we present kidney transplant outcomes of a unique Transatlantic Eurotransplant program in the former Dutch Antilles. All patients received a DBD donor kidney, preserved by HMP. Our study shows that DBD kidneys on a pump can endure prolonged CIT of ≥30 h. The present study with a larger and more homogeneous patient population extends preliminary results of this program.3 Donor kidneys of this report have exclusively been preserved by HMP using University of Wisconsin (UW) solution,5 and recipients were treated with a uniform immune suppression regimen. One-year GS rates in our current study have improved (93% versus 69% in the previous report3; P = 0.006) with comparable outcomes to our matched controls (93% versus 80% P = 0.216). These results show that outcomes of this Transatlantic program improved over the years, potentially explained by the improved screening of Antillean ESRD patients, thereby reducing dialysis vintage years while improving organ preservation with HMP. Those data emphasize on the preference of HMP lowering the risk of DGF,6,7,9,10 while improving 1- and 3-y GS in recipients of both DCD and DBD donor kidneys.6,8 HMP in our hands facilitated the successful implementation of a long-distance transplant program with CIT of ≥30 h. In summary, the experience of the transcontinental kidney transplant program between the Dutch Antilles and the Amsterdam UMC demonstrates its feasibility and success. Our analysis shows that very prolonged CIT is not a contraindication to proceed with kidney transplantation in the Dutch Antillean population when using DBD donor kidneys, preserved with HMP. Although the numbers are still relatively small, these results are encouraging for patients from small and relatively isolated communities. Furthermore, these results can contribute in lowering the threshold to ship donor kidneys over long-distances for difficult to match patients.