Background: Clinical trial data suggest that continuous hypothermic machine perfusion (HMP) during the entire preservation period reduces the incidence of delayed graft function and improves graft survival. This study evaluates whether short-term MP after cold storage (CS) is also effective.
Methods: Kidney function after cold preservation (4°C, 21 hr) and transplantation was studied in an autotransplant model using Landrace pigs (25-30 kg; n=5 per group) with 1 week follow-up. Preservation was performed by conventional CS or HMP with a modified Lifeport Kidney Transporter either continuously during the entire preservation period or only for 2 hr of hypothermic reconditioning (HR) subsequent to conventional CS.
Results: HMP and HR similarly improved cortical microcirculation and significantly reduced maximal serum creatinine levels and recovery of creatinine clearance to normal values compared with CS. Fractional excretion of Na+ was unaltered after HMP and HR but significantly increased until postoperative day 5 on CS. On a molecular level, HR reduced innate immunoreactivity (toll-like receptor 4 expression and high mobility group protein B1 [HMGB-1] release) and normalized antiinflammatory tissue expression of von Kruppel-like Factor-2.
Conclusion: Short-term reconditioning after CS proves to be as effective as continuous MP during the whole storage time. Because of its logistical convenience, the concept of an a posteriori treatment recommends itself to be evaluated in clinical trials.