Renal transplants from older deceased donors: Is pre-implantation biopsy useful? A monocentric observational clinical study

Abstract

AIMTo 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.METHODSRenal 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.RESULTSThere 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)].CONCLUSIONIn 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.

Evaluation of Expanded Criteria Donors Using the Kidney Donor Profile Index and the Preimplantation Renal Biopsy

“…The usefulness of preimplantation biopsy as a predictive tool for graft survival has not been validated yet and some studies discuss its value for the assessment of the quality of organs from ECD [ 15 , 18 - 20 ]. In our case, all the grafts had a preimplantation biopsy and only those with a global score <7 were accepted.…”

Histological and clinical evaluation of marginal donor kidneys before transplantation: Which is best?

“…Two recent Italian studies on the utility of pre-implantation biopsy in allocating ECD kidneys[4,55] concluded that histological evaluation was not superior to donor clinical evaluation in allocating ECD kidneys either as a single kidney or as a dual kidney transplant. The authors concluded that, according to their experience, the histological score poorly evaluates the donor kidney quality.…”

Comprehensive assessment of deceased donor kidneys with clinical characteristics, pre-implant biopsy histopathology and hypothermic mechanical perfusion parameters is highly predictive of delayed graft function

“…Histopathological evaluation of the donor kidney via biopsy is an important component of the comprehensive evaluation, especially for ECD evaluation [4,5]. The pre-implantation biopsy is performed not only to evaluate the potential chronic changes in renal structure, but also to assess ischemic injury in the donated kidney [11]. Hypothermic mechanical perfusion (HMP) has been shown to mitigate DGF by removing residual renal microthrombi, dredging renal micro vessels and provide measures to assess renal function [6,7,12].…”