Kidney Storage at Sub-Zero Temperature is Safe for Porcine Kidney Auto-Transplantation: A World First In-Vivo Study.

Abstract

Organ shortage continues to limit kidney transplantation worldwide. Sub-zero storage may harbor the potential for extending cold ischemic times, improving organ sharing, and optimizing graft allocation. However, sub-zero storage remains challenging, limited by possible freeze-thaw damage. We conducted a porcine auto-transplant model to assess kidney function and injury after brief (5 h) or prolonged (24-48 h) sub-zero storage of grafts, comparing it to classic static cold storage. There was no mortality in the cohort, and subjects were followed for 7 days. Creatinine, BUN and potassium peak levels and curves were comparable between groups in both brief and prolonged experiments (P > .05). Histological analysis revealed no evidence suggesting ice crystals had formed, as well as similar injury profiles, suggesting that the sub-zero preservation process was successful. Creatinine clearance, fractional excretion of sodium, NGAL urinary and serum levels tended to favor sub-zero preservation in the 24 h SCS experiments, without statistical significance. While further research is needed to optimize storage protocols and explore the impact of colder temperatures, this study provides promising evidence regarding safety and feasibility of sub-zero storage as a method for extending preservation times. Future studies will focus on enhancing preservation solutions for improved outcomes.