Background: Ex vivo organ storage and length of cold ischemia time (CIT) negatively impact on kidney graft survival and function in renal transplantation.
Grafts from extended criteria donors seem to be especially vulnerable to ischemic injury. The aim of this study was to evaluate a new therapeutic strategy based on the combination of ultrasounds and hypothermic conditions for kidney graft preservation.
Methods: Lewis rat donor kidneys were perfused with preservation solution, Celsior, and kept in cold storage at 4ºC (CS group) or in ultrasound device at 4ºC (US group) during 18h or 29h. Perfusate samples were collected to assess the renal damage. In addition, we performed a syngenic heterotopic renal transplantation (Lewis-to-Lewis) using kidneys with the above mention CIT with or without ultrasound device. Serum BUN and creatinine levels were measured daily to determine kidney function. The animals that survived were sacrificed 7 days after kidney transplant.
Results: Longer cold ischemia time was associated with worse rat survival in both CS and US groups. CS-18h survival was 55% and 0% in CS-29h (p=0.0147). In US-18h, rat survival was 100% (p=0.0273 vs CS-18h) whereas US-29h rat survival 33% (p=0.0281 vs CS-29h). Serum BUN and creatinine levels were restored earlier and were lower at day 7 in ultrasound groups. Ultrasound treatment was associated with lower NGAL and αGST concentration in perfusate at 29h of CIT.
Conclusions: Ultrasound treatment in addition to cold storage improves viability of syngenic kidney grafts and final graft function in a rat model of kidney transplantation.