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AIM: To compare survival of kidney transplants from deceased extended criteria donors (ECD) according to: (1) donor graft histological score; and (2) allocation of high score grafts either to single (SKT) or dual (DKT) transplant. METHODS: Renal biopsy was performed as part of either a newly adopted DKT protocol, or of surveillance protocol in the past. A total 185 ECD graft recipients were categorized according to pre-implantation graft biopsy into 3 groups: SKT with graft score 1 to 4 [SKT(1-4), n = 102]; SKT with donor graft score 5 to 8 [SKT(> 4), n = 30]; DKT with donor graft score 5 to 7 (DKT, n = 53). Graft and patient survival were analyzed by Kaplan-Meier curves and compared by log-rank test. Mean number of functioning graft years by transplant reference, and mean number of dialysis-free life years by donor reference in recipients were also calculated at 1, 3 and 6 years from transplantation. RESULTS: There were no statistically significant differences in graft and patient survival between SKT(1-4) and SKT(> 4), and between SKT(> 4) and DKT. Recipient renal function (plasma creatinine and creatinine clearance) at 1 years did not differ in SKT(1-4) and SKT(> 4) (plasma creatinine 1.71 ± 0.69 and 1.69 ± 0.63 mg/dL; creatinine clearance 49.6 + 18.5 and 52.6 + 18.8 mL/min, respectively); DKT showed statistically lower plasma creatinine (1.46 ± 0.57, P < 0.04) but not different creatinine clearance (55.4 + 20.4). Due to older donor age in the DKT group, comparisons were repeated in transplants from donors older than 70 years, and equal graft and patient survival in SKT and DKT were confirmed. Total mean number of functioning graft years by transplant reference at 1, 3 and 6 post-transplant years were equal between the groups, but mean number of dialysis-free life years by donor reference were significantly higher in SKT (mean difference compared to DKT at 6 years: 292 [IQR 260-318] years/100 donors in SKT(1-4) and 292.5 [(IQR 247.8-331.6) in SKT(> 4)]. CONCLUSION: In transplants from clinically suitable ECD donors, graft survival was similar irrespective of pre-implantation biopsy score and of allocation to SKT or DKT. These results suggest use of caution in the use of histology as the only decision criteria for ECD organ allocation.
RESUMEN
BACKGROUND: Grafts from elderly donors (ECD) are increasingly allocated to single (SKT) or dual (DKT) kidney transplantation according to biopsy score. Indications and benefits of either procedure lack universal agreement. METHODS: A total of 302 ECD-transplants in period from Jan 1, 2000, to Dec 31, 2015, were allocated to SKT (SKTpre) on clinical grounds alone (before Dec 2010, pre-DKT era, n = 170) or according to a clinical-histological protocol (after Dec 2010, DKT era, n = 132) to DKT (n = 48), SKT biopsy-based protocol ("high-risk", SKThr, n = 51), or SKT clinically based protocol ("low-risk", SKTlr, n = 33). Graft and patient survival were compared between the two periods and between different transplant categories. RESULTS: Graft and overall survival in recipients from ECD in pre-DKT and DKT era did not differ (5-year graft survival 87.7% and 84.2%, resp.); equal survival in the 2 ECD periods was shown in both donor age ranges of 60-69 and >70-years, and in low-risk or high-risk ECD categories. Within the DKT protocol SKThr showed worst graft and overall survival in the 60-69 donor age range; DKT did not result in significantly better outcome than SKT from ECD in either era. One-year posttransplant creatinine clearance in recipients did not differ between any ECD transplant category. At 3 and 5 years after transplantation there were significantly higher total dialysis-free recipient life years from an equal donor number in the pre-DKT era than in the DKT protocol. CONCLUSIONS: Use of a biopsy-based protocol to allocate grafts from aged donors to SKT or DKT did not result in better short term graft survival than a clinically based protocol with allocation only to SKT and reduced overall recipient dialysis-free life years in time.