Introduction: Increasing rates of end stage kidney disease in Asia, including Korea, are very high; however, the rates of deceased donation in this area is much lower than those in the Western countries, leading to a serious discrepancy between donor organ need and supply. Therefore, efficient utilization of deceased donor kidneys with minimizing organ discard is essential.
Method: This nationwide study included deceased donor kidneys which are candidate for kidney transplantation (KT) between 2013 and 2018 in the Korean Network for Organ Sharing. Kidneys were procured bilaterally or unilaterally, or discarded bilaterally. Unilaterally- or bilaterally-procured kidneys were used for KT or discarded later. Kidney discard was defined as no-procurement or discard after procurement. We analysed risk factors affecting donor kidney discard using multivariable logistic regression analysis. Moreover, we analysed graft failure rate and mortality in KT patients according to discard pattern using Log rank test and multivariable Cox regression analysis.
Results: Among 5,592 deceased donor kidneys, numbers of no-procurement, single-procurement, and double-procurement were 385, 63, and 5,144, respectively. Most of unilaterally-procured kidneys except one were transplanted. Bilaterally-procured kidneys were accompanied by two transplantations (n=5,058), one transplantation with discard of the other kidneys (n=33), or discard of both kidneys (n=20). The kidney discard rate was 7.9% (n=439), which seemed to be lower compared to that in the Western countries. The causes of no-procurement were universally organ damage and the common causes of kidney discard after procurement were organ damage (66.6%) and absence of available candidates (12.9%). While mean kidney donor profile index (KDPI) in the discard group (1.9 ± 0.7) was higher than that of KT group (1.5±10.5, P < 0.001), a large overlap in the quality was observed. Risk factors for kidney discard were female sex (adjusted odds ratio [OR], 1.68), hypertension (OR, 1.65), diabetes mellitus (OR, 2.82), high serum creatinine levels (OR, 1.89), low hemoglobin levels (OR, 0.84), and non-cerebrovascular cause of death (OR, 0.70). When KT using contralateral kidneys in the discard group was compared with that in the no-discard group, there were no significant differences in either graft failure rate or mortality between the two groups (P = 0.300). Furthermore, multivariable analysis showed that discard of the contralateral kidneys did not have a negative impact on either graft survival (hazard ratio 1.67; P =0.216) or patient survival (hazard ratio 0.86; P =0.749).
Conclusion: The discard rate of deceased donor kidneys was low in Korea with a very long waiting time and KT outcomes using contralateral kidneys in the discard group were comparable to those in the no-discard group, supporting maximal utilization of deceased donor kidneys would contribute to expanding a donor pool without compromising post-transplant outcomes.