Commentary Commentary on: Lipid peroxidation in machine perfusion of older donor kidneys Georgios Tsoulfas, MD, PhD, FACS* Department of Surgery, Aristoteleion University of Thessaloniki, Thessaloniki, Greece article info Article history: Received 27 June 2012 Received in revised form 27 June 2012 Accepted 3 July 2012 Available online 21 July 2012 It is a universally accepted fact that kidney transplantation improves quality of life and patient survival in patients with end-stage renal disease [1]. However, the success of renal transplantation has generated its biggest challenge, which is none other than the growing disparity between available organs on the one hand and the increasing need on the other hand. According to data from the United Network for Organ Sharing (UNOS), the annual increase of patients on the trans- plant waiting list is approximately five times the number of transplantation procedures, leading to a 6% mortality rate for patients on the waiting list for a renal transplant [2,3]. To this we should add changes in the donor characteristics, with the type of donor more frequently encountered nowadays not being the young trauma victim, but rather an elderly donor deceased because of a cerebrovascular accident or cardiovas- cular disease [4]. Given the loss of life on the waiting list, it is not surprising that it has been shown that receiving any kidney is a better option compared with remaining on the waiting list [5]. These findings have led to attempts to expand the donor pool, including the use of higher-risk or “marginal,” or expanded criteria renal grafts. The main characteristic of these kidneys is their origin from older donors, accompanied by an increased risk of primary nonfunction (PNF) or delayed graft function (DGF) [6,7]. This has led to the goal of optimizing renal function of these grafts, in an effort to improve their results. One of these methods has been machine perfusion; although originally developed in the 1960s as a more physiologic method of renal preservation, it was later limited to being used for expanded criteria kidneys [8,9] because of issues of cost and complexity. Proponents of this method of preservation stress its value as both a potential assessment method of a marginal renal graft, as well as a way to improve its function. The paper by Nagelschmidt et al. attempts to identify criteria that would enable a pretransplant evaluation of the quality of the graft, so as to avoid using extended criteria organs that would not function [10]. This effort was based on machine perfusion technology and the possibility that it offers of deter- mining biomarkers in the perfusion solution from which predictions can be made. The authors in the present study evaluated the machine perfusates of kidneys recovered from donors who were aged 55 y or older, as a subgroup with poten- tially increased risk of complications. From the six measured perfusate biomarkers, only lipid peroxidation products were found to be an independent predictor for the occurrence of significant complications after transplantation. The importance of this work lies in the fact that it attempts to identify on DOI of original article: 10.1016/j.jss.2012.04.071. * Corresponding author. Department of Surgery, Aristoteleion University, 66 Tsimiski Street, Thessaloniki 54622, Greece. E-mail address: tsoulfasg@gmail.com. Available online at www.sciencedirect.com journal homepage: www.JournalofSurgicalResearch.com journal of surgical research 185 (2013) e43 ee44 0022-4804/$ e see front matter ª 2013 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.jss.2012.07.009