10 °C Storage for the Preservation of Pig Kidney Grafts: A Porcine Autotransplant Model

Background. Optimization of organ storage is essential to improve outcomes in kidney transplantation. Recent studies in lung transplantation highlight the impact of temperature on organ preservation, leading to a shift from traditional 4 °C “on-ice” storage toward 10 °C. We sought to determine whether these findings extend to kidney transplantation using 2 distinct porcine autotransplant models. Methods. The initial donation after circulatory death model consisted of 30 min of warm ischemia followed by a brief 7.5 h storage on-ice (n = 5) or at 10 °C (n = 5). Grafts were retransplanted, the contralateral kidney was removed, and participants were followed up for 3 d. A second model simulating donation after brain death compared 24-h storage at 10 °C (n = 3) to a contemporaneous standard ice storage cohort (n = 3), followed by transplant, contralateral nephrectomy, and 7-d follow-up. Results. The first model revealed discrete differences in creatinine, blood urea nitrogen, sodium, potassium, urine output, creatinine clearance, and fractional sodium excretion favoring 10 °C ( P > 0.05). Histology revealed reduced tubular injury ( P = 0.03) and interstitial inflammation ( P < 0.05) in the 10 °C group. Urinary neutrophil gelatin-associated lipocalin and thiobarbituric acid reactive substances were also reduced at 10 °C in the postoperative period ( P > 0.05). However, prolonged 24-h storage at 10 °C did not benefit kidney function, with significantly worse creatinine and blood urea nitrogen values over time ( P < 0.05). Conclusions. The results of this initial study suggest that 10 °C storage may offer a modest protective effect in a short-storage porcine donation after circulatory death autotransplantation model; however, no benefit was demonstrated with prolonged storage, suggesting that any potential effects may be organ- and preservation solution-specific, as well as time-dependent. Larger studies are needed to draw more definitive conclusions.