신장이식수술에서 신장이식 공여자에 시행한 원격 허혈 양상화가 수술 후 신기능에 미치는 영향

Abstract

Backgrounds: Remote ischemic preconditioning (RIPC) has been reported to protect renal function through anti-inflammatory reaction, but whether RIPC could reduce renal injury occurring in the residual kidney of living donor is not known. The purpose of this study is to evaluate effect of RIPC on recovery of postoperative residual renal function and long-term prognosis in living kidney donor. Methods: We conducted a prospective, double-blind, randomized, controlled trial involving living kidney donors who were scheduled for elective kidney transplantation. RIPC was performed on the upper arm and compared with sham procedure. We compared the proportion of patients whose serum creatinine level was greater than the upper normal limit which is 1.4 mg/dL at the time of discharge. Serum creatinine and estimated glomerular filtration rate (eGFR) until a year after operation were measured. Multivariate logistic regression analysis was performed to find the predictors for elevated serum creatinine at discharge. In addition, we evaluate a predicting ability of cystatin C and search a cutoff value predicting serum creatinine level over 1.4 mg/dL at the time of discharge using receiver operating characteristic (ROC) curve analysis. The incidence of chronic kidney disease (CKD) at one year after operation was also measured. Results: Between April 2016 and August 2017, 170 patients were included and randomized to each group (85 in the RIPC group and 85 in the control group). The proportion of patients whose serum creatinine level was greater than 1.4 mg/dL at the time of discharge was greater in the control group (17 patients [20%] vs. 6 patients [7.1%]; p = 0.025). Levels of postoperative serum creatinine were significantly greater in the control patients as compared with the RIPC group at postoperative day 2 and 3 (1.2 mg/dL, 95% confidence interval [CI] 0.9–1.5 vs. 1.0, 95% CI 0.9–1.2 and 1.3 ± 0.3 mg/dL vs 1.0 ± 0.2 mg/dL; p = 0.009 and p < 0.001, respectively). Levels of eGFR were significantly lower in control groups at postoperative day 3 (67.1 ± 13.0 ml/min/1.73m2 vs 75.3 ± 12.6 ml/min/1.73m2; p = 0.018). No significant difference in the serum creatinine or eGFR was observed until a year post-surgically. The predictors of elevated serum creatinine at discharge are RIPC (Odd ratio [OR] 0.26, 95% CI 0.07–0.82; p = 0.029), Age (OR 0.89, 0.83–0.95; p < 0.001), eGFR (OR 0.95, 0.90–0.85; p < 0.001), postoperative cystatin C which was measured within 24 hours after operation (OR 1.84, 95% CI 1.24–2.85; p = 0.004). ROC analysis shows that the cut-off value of postoperative cystatin C predicting serum creatinine > 1.4 mg/dL at discharge was 0.9 mg/L and the area under the curve was 0.82 (sensitivity 95.7%, specificity 66.9%). There was no significant difference in the incidence of CKD at one year after operation (6 patients [7.1%] vs. 8 patients [9.4%]; p = 0.78). Conclusion: RIPC is a helpful procedure to improve immediate postoperative renal function of kidney donors. In addition, postoperative cystatin C is useful diagnostic marker for prediction of renal injury.