Background: Traditionally, the criteria of splitting pediatric en bloc kidneys for transplantation into two adults includes: donor age > 3 years, donor weight > 12kg, or kidney length > 6cm. To expand the donor pool, we investigated the feasibility and safety of the single kidney transplantation from pediatric donors younger than 3 years to adult recipients.

Methods: From 2014.9 to 2015.9, a total of 21 single kidney transplants from pediatric DCD (donation after citizen death) donors younger than 3 years (8-26 months) were performed in our center. Almost all recipients were adult patients except 2 children. Here we summarized the outcome of these small single kidney allografts in 19 adult recipients.

Results: The average donor age was younger than 2 years (18.0±6.1m), with 4 donors younger than 1 year. The youngest donor was only 8 months. The average donor weight was less than 12kg (11.6±5.2kg), and the average kidney lengths was about 6cm (6.3±0.6cm). The causes of donor death include intracranial tumor (2 cases), severe congenital dysplasia (2 cases), trauma (5 cases), asphyxiation (1 case), and unknown cause (1 case). The average warm ischemia time was 11.5±4.3min. For the 19 adult recipients, the average age was 30.0±9.6 years and the average body weight was 45.8±6.2kg (38-52 kg). The majority of the patients were female (68.4%), and all except one of these patients were transplanted for the first time. The average follow-up time was 12 months. Delayed graft function (DGF) was observed in 3 patients (16%). Most patients (16/19) had a satisfied urine output immediately after the small single kidney transplantation, however, the serum creatinine levels decreased relatively slower in the early period (Fig 1). The average value of eGFR was steadily increased to normal during the 1year follow-up period (Fig 2). Additionally, only one renal graft developed acute rejection (5%), which was successfully reversed by the treatment of high dosed of steroids.

Conclusion: By choosing appropriate adult recipients, excellent short-period transplant outcome can be achieved by using small single kidneys from pediatric donors younger than 3 years, which may represent an important way to expend the donor pool for kidney transplantation.