Factors Related to Suboptimal Recovery of Renal Function after Living Donor Nephrectomy

Abstract

Introduction Renal function of the living donor usually recovers to 60~70 percent of baseline function by compensatory hypertrophy mechanism. However, the degree of this compensatory hypertrophy varies from donor to donor and the factors related to the degree of this mechanism are little known. Materials and Methods We retrospectively analyzed 103 living donors of whom completed one-year follow-up after the laparoscopic donor nephrectomy from 2011 to 2016 in our institution. Of these, 39 cases were defined as suboptimal compensatory hypertrophy group. The definition of this group was as follows: If 1) 1-year eGFR was less than 60% of baseline eGFR, and if 2) 1-year eGFR was less than predicted one calculated by the correlation coefficient method. The rest of the donors were defined as a control (compensatory hypertrophy group, n=64). We investigated the factors related to the suboptimal recovery of the renal function after living donor nephrectomy. Result Although baseline eGFRs were the same in the two groups (control: 82.4±13.5mL/min/1.73m2 vs suboptimal compensatory hypertrophy group: 82.9±14.4mL/min/1.73m2, p=0.88), donor age (control: 55.8±10.4 vs suboptimal compensatory hypertrophy group: 61.1±8.5, p=0.009), uric acid (control: 4.8±1.1mg/dl vs suboptimal compensatory hypertrophy group: 5.5±1.3mg/dl, p=0.005) and hemoglobin A1c (control: 5.3±0.38mg/dl vs suboptimal compensatory hypertrophy group: 5.5±0.42mg/dl, p=0.002) were significantly higher in the suboptimal compensatory hypertrophy group compared to the control. Pathological chronicity finding on one-hour biopsy (ah≧1 + ct+ci≧1) were much higher in the suboptimal compensatory hypertrophy group than the control (control: 6.5% vs suboptimal compensatory hypertrophy group: 26.3%, p=0.008). After the multivariate logistic regression analysis, pathological chronicity finding (odds ratio 4.3, 95% confidence interval 1.1-15.9, p=0.031) and higher hemoglobin A1c level (per 0.1%: odd ratio 1.2, 95% confidence interval 1.0-1.3, p=0.014) were found to be independent risk factors for suboptimal compensatory hypertrophy. Conclusion Pathological chronicity finding on one-hour biopsy and higher hemoglobin A1c level were associated with suboptimal recovery of the one-year renal function after living donor nephrectomy.