The effect of renal ischemia-reperfusion injury on the function of renal allograft was investigated after donation after cardiac death (DCD) renal transplantion.

We retrospectively analyzed the clinical data of renal transplant donors and recipients at the Kidney Disease Center of the First Affiliated Hospital of Zhejiang University from May 2011 to June 2015. One year after transplantation, the recipients were classified into high renal function group [estimated glomerular filtration rate (eGFR) ] ≥60 mL·min^-1·(1.73 m²)^-1) and low renal function group (eGFR <60 mL·min^-1·(1.73 m²)^-1. According to the DCD donor surgery record, the systolic blood pressure (SBP) and blood oxygen saturation (SpO₂) of the donors during different periods of warm ischemia in two groups were analyzed. The normal distribution measurement data were showed as the mean±standard deviation (±s), and the t-test was used to compare the basic characteristic data, donor SBP and SpO₂ in the different warm ischemia periods between the two groups, except for gender. The Wilcoxon Signed Rank test was used to compare the pathological scores of glomerular and glomerular of donor kidneys between two groups when organ procurement. Count data were expressed as a percentage. Chi-square test was used to compare the donor gender and DGF incidence in the two groups. P<0.05 was considered statistically significant.

By June 2016, all patients were followed up (28.4±2.8) months, ranged from 13.1 to 62.5 months. 340 recipients were eventually included, including 259 recipients in the high renal function group and 81 recipients in the low renal function group. The incidence of DGF was 14.7% (38/259) and 22.2% (18/81) in high and low renal function groups within 1 year after transplantation, with no significant difference (χ²=2.557, P>0.05). The average age and BMI of donors in the high renal function group were lower than those in the low renal function group, and the percentage of males and eGFR at the time of donation was higher than that in the low renal function group (t=-6.363, -2.049, 4.190, χ²=4.863, P all <0.05). The renal pathology scores of donors with high renal function were lower than those with low renal function, and the difference was statistically significant (Z=-2.606, P<0.05). The recipients of the high renal function group were younger than the low renal function group, and the proportion of males was higher than the low renal function group, with significant difference (t=-2.790, χ²=9.658, P<0.05). In the high and low renal function groups, the initial SpO₂ decreased by 40%, the average time from life support device withdrawal, different initial SpO₂ with 90%, 80%, 70%, 60% of to SpO₂ to SpO₂ could not be measured, were (5.9±4.3) and (4.8±3.3), (8.0±5.2) and (6.1±4.4), (4.5±3.6) and (3.5±2.8), (4.0±3.7) and (2.9±2.4), (4.0±3.6) and (2.8±2.7), (3.6±3.5) and (2.4±2.5) minutes, with significant difference (t=2.088, 2.983, 2.328, 2.622, 2.557, 2.759, all P<0.05). In the high and low renal function groups, the average change rate of initial SpO₂ declined by 10%, 40%, life support device withdrawal to SpO₂ not detected, initial 60% SpO₂ to SpO₂ not detected were (2.40±1.78) and (2.90±1.70), (8.71±6.96) and (15.01±12.97), (19.60±17.49) and (25.80±22.85), (22.41±15.94) and (29.93±19.36) percentage per minute, with significant difference (t=-2.230, -5.647, -2.577, -3.514, P all <0.05).

The prognosis of DCD renal transplantation was influenced by the general factors such as donor and recipient age and BMI. The high and low renal function recipients had different high and low SpO₂ time intervals and different rates of change derived from the DCD donors. During DCD renal transplantation, optimized surgical procedures should be taken to minimize the low SpO₂ duration, so that the warm ischemia damage of the donor would be alleviated to acheive a better prognosis of tranplant.