Prospective randomized comparison of University of Wisconsin and UW-modified, lacking hydroxyethyl-starch, cold-storage solutions in kidney transplantation.

University of Wisconsin cold storage solution differs from Euro-Collins by the presence of adenosine, allopurinol, and hydroxyethyl starch, which maintains osmotic pressure. It is now experimentally and clinically well established that the use of UW solution is associated with better liver graft recovery parameters after prolonged cold ischemia time. However, it has been also suggested in animal experiments that HES might not be essential for optimal kidney preservation, at least when cold ischemia time remains within 48 hr. Herein, we present a randomized study comparing UW (n = 44) and a modified UW (UW-mod) (n = 44) solution lacking HES, adenosine, and allopurinol on kidney graft recovery parameters. Forty-one consecutive Euro-Collins flushed kidneys, transplanted immediately before this randomized trial, were used as historical controls. The results indicate that UW-mod was as efficient as UW in preserving the kidney in cold ischemia ranges that did not exceed 48 hr. Both solutions (UW and UW-mod) seemed more effective than Euro-Collins, based on the analysis of several parameters including the number of days until the creatinine was < 300 microM (P < 0.05), the level of the serum creatinine at one month (P < 0.02), and the Cockroft index (P < 0.04). Since UW-mod is three times less expensive than UW, we suggest that the simplified solution could be routinely used to preserve kidneys for transplantation.