Optimizing Recovery, Utilization and Transplantation Outcomes for Kidneys From Small, ≤20 kg, Pediatric Donors

Abstract

The optimal balance between maximizing the number versus the outcome of transplantation utilizing kidneys from small (≤20 kg) pediatric donors remains unclear, complicated by the choice of single versus en bloc transplantation with their attendant technical risks. Using the Organ Procurement and Transplantation Network (OPTN) database, we examined kidney recovery and utilization patterns, and 1‐year transplant outcomes by single kilogram weight strata. Between January 1, 2005 and June 30, 2010, 2352 kidneys from ≤20 kg donors were transplanted into 1531 recipients, 710 single kidney transplants (SKTs) and 821 en bloc kidney transplants (EBKTs). Increased donor weight was associated with higher rates of recovery, transplantation and SKT. Low donor weight (linear p < 0.001; quadratic p = 0.003), SKT versus EBKT (p = 0.008), increased cold ischemia time (p = 0.003), local versus nonlocal donor (p = 0.0044), low versus high volume center (p = 0.003) and the interaction term between center volume and donor weight (p = 0.0024) were associated with graft failure. Notably, lower donor weight exacerbated the negative impact of low center volume but did not worsen the negative impact of SKT on outcomes. Our data show that EBKT offers superior 1‐year survival at the expense of accomplishing one rather than two transplants. However, SKTs yield excellent outcomes when performed at experienced centers.

Kidney Donor Profile Index Does Not Accurately Predict the Graft Survival of Pediatric Deceased Donor Kidneys

“…Kidneys from donors <1 year had uniquely worse performance due to very early graft failure (see Figure S1). As previously reported, (5,7,14,15), a substantial survival advantage was found for en bloc grafts (adjusted Hazard ratio (HR) 0.661, p<0.001) (see Figure S2). The categorical underweight for age covariate (<25 th percentile of CDC gender-adjusted weight-for-age growth chart) was found to predict graft performance better than a continuous weight covariate used in KDPI (adjusted HR 1.141 if donors were light for age, p=0.082).…”

“…In addition, we identified several model covariates that are absent from KDPI but are significantly associated with graft survival in the Cox multivariate analysis (see Tables 2 and 4). For example, although Rao and colleagues (1) found en bloc to be significant in their original Cox regression, and others have also shown en bloc versus SKT as an important predictor for graft performance, (5,7,14,15) it was decided not to include this criterion in KDPI because it is not a donor characteristic per se and is subject to surgeon/center practice pattern variation. However, en bloc is a donor graft characteristic that can be known prior to transplantation.…”

Singlevsdual (en bloc) kidney transplants from donors ≤ 5 years of age: A single center experience

“…However, unlike kidneys from older donors, kidneys transplanted from pediatric donors into adult recipients have the capacity to grow to a normal adult renal size within a few months of KT and represent an underutilized resource [39] . Both conversion and utilization rates are lower with younger DD age [3,31,33] . Small pediatric donor KT is gaining wider acceptance but is still regarded as controversial by some and is not universally accepted.…”

“…Previous studies have suggested that pediatric dual EB KT should be performed for donors < 10 kg whereas "splitting" kidneys for use in two recipients is appropriate when the donor is > 20 kg in size [20,24,26] . However, donors weighing between 1020 kg re present a "gray area" in achieving the proper balance between utilization and outcomes [31,33] . In a large retrospective UNOS registry analysis of donors < 10 years of age from 19952007, Kayler et al [24] reported that kidneys from donors with a 1519, 1014, and < 10 kg body weight were used for dual EB KT in 40%, 65%, and 86% of adult recipients, respectively [24] .…”

Neonatal organ donation for transplantation in the UK

“…Organ donation from very young donors is a rare occurrence in the UK, which is a testament to our outstanding neonatal and paediatric care but may also reflect overall lower donation rates compared with other countries. In the USA, Maluf et al 4 reported on 431 donors under 8 kg in weight, which resulted in 129 kidney transplants (84% as en bloc kidney pairs into a single recipient) from 2005 to 2010.…”