Korean J Transplant.  2021 Oct;35(Supple 1):S108. 10.4285/ATW2021.OP-1274.

Impact of donor kidney weight to recipient body weight ratio on long-term graft outcomes in live donor kidney transplantation

• Lee J
• Yang SJ
• Kim HJ
• Kim BS
• Kim MS
• Kim SI
• Huh KH

• KMID: 2521368
• DOI: http://doi.org/10.4285/ATW2021.OP-1274

Abstract

Background
Kidney weight has been suggested as a surrogate marker for nephron numbers and renal function. Small donor kidney sizes relative to recipient body size is an important contributor to short-term graft renal function, but the impact of size mismatching on long-term graft outcomes remains unknown. This study is aimed to evaluate the impact of the donor kidney weight to recipient body weight ratio (KW/BW) on long-term graft survival in live donor kidney transplantation.
Methods
We performed a longitudinal cohort study in 1,397 patients who underwent live donor kidney transplantation between 2000 and 2016 at a single center. Following cold perfusion and back table surgery, the kidney was weighted on the same electronic weighting scale by the surgeon. Patients were grouped into four groups according to KW/BW quartiles.
Results
During a median follow-up of 127 months, 245 graft loss occurred (172 graft failures and 73 patient deaths). The 10-year death-censored graft survival rates were 86.9% in the lowest quartile, 90.4% in the second quartile, 90.5% in the third quartile, and 92.4% in the highest quartile (P=0.002). Multivariable analysis revealed that the lowest KW/BW (hazard ratio [HR], 2.16; 95% confidence interval [CI], 1.33–3.48; P=0.002) and second lowest KW/BW (HR, 1.69; 95% CI, 1.06–2.70; P=0.029) groups were significantly associated with death-censored graft failure compared with the highest KW/BW group. Patients with lower KW/BW exhibited consistently lower estimated glomerular filtration rates than those with higher KW/BW.
Conclusions
Low KW/BW is significantly associated with long-term graft outcome in live donor kidney transplantation.