Comparison of the effectiveness of Et-Kyoto with Euro-Collins and University of Wisconsin solutions in cold renal storage

Background. Previously, we developed a new organ preserving solution, ET-Kyoto solution (ETKS), and showed that it is effective for lung and skin cold storage. Our high sodium-low potassium solution containing trehalose and gluconate is chemically stable at room temperature. In this study, the efficacy of ETKS for renal cold storage compared with Euro-Collins solution (ECS) and University of Wisconsin solution (UWS) was investigated. Methods. A preflush of Krebs-Henseleit buffer was used before cold storage because ECS and UWS, but not ETKS, failed to be distributed thoroughly into each renal segment when directly flushed, as determined by staining with trypan blue. The kidneys were stored at 4degreesC in each solution after the preflush and were reperfused 24 hr later for 120 min with 37degreesC Krebs-Henseleit buffer containing albumin. For physiological evaluation, perfusion flow rates, creatinine clearance, and fractional sodium reabsorption were evaluated. Histological examination also was performed to determine tubular, glomerular, and interstitial changes. Moreover, distribution of perfusate at the beginning of reperfusion was assessed by using trypan blue. Results. The kidneys preserved in ETKS and UWS showed better physiological function and less histological damage than those preserved in ECS. Furthermore, at the beginning of reperfusion using trypan blue, almost all renal segments were stained in e ETKS and UWS groups, whereas they were partially stained in the ECS group. Conclusions. These results indicate that this simple and chemically stable solution, ETKS, could be a promising substitute for UWS.