Optimizing Allocation of Kidneys from Older Donors: Between Resources and Results

Abstract

To the Editor: We read with interest the comments of Ruggenenti et al. (1) on our recent, single center, nonrandomized, experience which is entitled ‘Technical aspects of unilateral dual kidney transplantation (DKT) from expanded criteria donors (ECDs): experience of 100 patients’ (2). There is an obvious need to optimize the selection of ECDs and their allocation since the discard rate of these kidneys was 44% in the United States in 2009 (3). Many of these kidneys could possibly have been used for single or DKT. However, the decision is a difficult one, especially under time constraint, as discussed in the recent editorial by Shapiro et al. (3). We recently discussed the ‘transplantability’ of ECD kidneys and the selection criteria used to allocate them to single or DKT (4). Transplantation centers may make this decision based on a single criterion or on a comprehensive assessment, as we did (2, 4). However, we believe that, although several selection criteria have been proposed to determine the ‘transplantability’ of ECD kidneys, comprehensive clinical and histological assessment before transplantation remains necessary (4). Nonetheless, we agree with Shapiro et al. that we lack precise national- or international-based selection criteria to guide clinicians (3). As part of the North Italian Transplant program (NITp), we use the NITp allocation criteria for older donors (2). Histological assessment forms part of the allocation criteria and should be performed when indicated (2). In our recent report, we did not describe the detailed assessment of pretransplantation histopathology because (i) the main aim was to describe the details of the surgical technique and outcomes of unilateral DKT and (ii) biopsy details have been discussed several times elsewhere (5, 6). However, we emphasize that the Remuzzi Score System (5, 6) was used in making the final decision on the allocation of the kidneys. Therefore, we agree with Ruggenenti et al. (1) that pretransplant kidney biopsy optimizes the utilization and allocation of kidneys from ECDs and may lead to optimal outcomes not only from donors >60 years (5, 6) but also from donors >70 years (7). However, ours was a single center-based (a program-based) experience from the NITp on the utilization and value of pretransplant biopsies. Shapiro et al. (3) stated that in comparing United States with European practices, it could be concluded that the biopsy actually increases the percentage of kidneys discarded. However, according to our experience at the NITp, the pretransplant biopsy is an important tool to optimize the allocation and utilization of ECD kidneys (2, 5-7). At present, the NITp-based criteria has demonstrated optimal results with ECDs, suggesting that, in some cases, kidneys allocated as DKT could have been suitable for single transplantation. Therefore, an adjustment of the Remuzzi Score System could be taken into consideration such as narrowing the indication for DKT from those ECD kidneys with higher scores. However, we must still bear in mind that the use of very old donors should guarantee an acceptable graft survival as the highest priority, if not possible a reduced number of transplantations would be an acceptable price to pay.