Pediatric en bloc kidney transplantation from very small (≤10 kg) donation after circulatory death (versus brain death) donors: Single-center matched-pair analysis of 130 transplants

Long-term Outcomes of Single and Dual En Bloc Kidney Transplants From Small Pediatric Donors: An ANZDATA Registry Study

Kidney transplants from small pediatric donors are considered marginal and often transplanted as dual grafts. This study aimed to compare long-term outcomes between recipients of single kidney transplants (SKTs) and dual en bloc kidney transplants (EBKTs) from small pediatric donors.

Methods

Data were obtained from the Australia and New Zealand Dialysis and Transplant Registry. All adult recipients of kidney transplants from donors aged ≤5 y were identified. The primary outcome of interest was death-censored graft survival by donor type. The secondary outcomes were early graft loss, delayed graft function, serum creatinine posttransplantation, acute rejection, and patient survival.

Results

There were 183 adult recipients of kidney transplants from donors aged ≤5 y old. Of these, 60 patients had EBKT grafts, 79 patients had SKT grafts, and 44 patients had grafts of unknown type. Compared with SKT donors, EBKT donors had lower mean age (P < 0.001) and body weight (P < 0.001). There was no significant difference in death-censored graft survival between the groups, with median survival of 23.8 y (interquartile range 21.2-25) in the EBKT cohort and 21.8 y (11.6-26.8) in the SKT cohort (hazard ratio 1.3; 95% confidence interval, 0.59-2.64; P = 0.56). EBKT grafts had lower acute rejection rates than SKT grafts (P = 0.014). There was no significant difference observed between groups with respect to early graft loss, delayed graft function, posttransplantation serum creatinine posttransplantation, or patient survival.

Conclusions

EBKT and SKTs from small pediatric donors are associated with excellent long-term graft survival rates.

The Outcome of Transplanting Kidneys From Very Small Pediatric Deceased Donors

BACKGROUND

Kidneys from very small pediatric donors (VSPDs, aged <2 y) are underutilized. Concerns regarding potentially inferior outcomes hinder the use in pediatric recipients.

METHODS

All pediatric kidney-only transplants from <18-year-old donors between January 2012 and May 2021 in our center were included in this study. Outcomes were compared between VSPD and normal pediatric donor (NPD, aged 2-18 y) groups, and 3-y death-censored graft survival was assessed by the multivariable Cox proportional hazard model.

RESULTS

Of all 252 enrolled patients, 149 (59.1%) received kidneys from NPDs and 103 (40.9%) from VSPDs. The 3-y graft survival rates of the NPD and VSPD groups were 91.2% and 88.6%, respectively ( P = 0.385). The adjusted hazard ratio of 3-y graft loss was 1.2 (95% confidence interval, 0.6-2.5; P = 0.659) for the VSPD group compared with the NPD group. There was no significant difference in estimated glomerular filtration rate at 3 y posttransplant observed between NPD and VSPD groups (86.9 ± 26.8 versus 87 ± 27.9 mL/min/1.73 m 2 ; P = 0.991). Patients (n = 12, 4.8%) who received kidneys from donors <5 kg contributed 5 (5/39, 12.8%) with delayed graft function and the sole primary nonfunction in our cohort.

CONCLUSIONS

Although attention to preventing complications is necessary, especially for kidneys from donors <5 kg, kidneys from VSPDs did not appear to impart added risk for 3-y graft loss and renal function.

Long-term Survival of Grafts From Small and Very Small Pediatric Donors in Women vs Men With End-stage Kidney Disease

This cohort study compares graft survival of kidneys from small and very small pediatric donors in women vs men with end-stage kidney disease.

Normothermic Regional Perfusion in Pediatric Controlled Donation After Circulatory Death Can Lead to Optimal Organ Utilization and Posttransplant Outcomes

BACKGROUND

The benefits of normothermic regional perfusion (NRP) in posttransplant outcomes after controlled donation after the determination of death by circulatory criteria (cDCD) has been shown in different international adult experiences. However, there is no information on the use of NRP in pediatric cDCD donors.

METHODS

This is a multicenter, retrospective, observational cohort study describing the pediatric (<18 y) cDCD procedures performed in Spain, using either abdominal NRP or thoracoabdominal NRP and the outcomes of recipients of the obtained organs.

RESULTS

Thirteen pediatric cDCD donors (age range, 2-17 y) subject to abdominal NRP or thoracoabdominal NRP were included. A total of 46 grafts (24 kidneys, 11 livers, 8 lungs, 2 hearts, and 1 pancreas) were finally transplanted (3.5 grafts per donor). The mean functional warm ischemic time was 15 min (SD 6 min)' and the median duration of NRP was 87 min (interquartile range, 69-101 min). One-year noncensored for death kidney graft survival was 91.3%. The incidence of delayed graft function was 13%. One-year' noncensored-for-death liver graft survival was 90.9%. All lung and pancreas recipients had an excellent evolution. One heart recipient died due to a septic shock.

CONCLUSIONS

This is the largest experience of pediatric cDCD using NRP as graft preservation method. Although our study has several limitations, such as its retrospective nature and the small sample size, its reveals that NRP may increase the utilization of cDCD pediatric organs and offer optimal recipients' outcomes.

Potential of neonatal organ donation and outcome after transplantation

Organ transplantation is limited by access to suitable organs. Infant recipient waitlist mortality is increased due to the scarcity of size-matched organs. Neonatal organ donors have been proposed as an underutilized source of donor organs. However, the literature on the actual prevalence and outcome of neonatal organ donation and transplantation is fragmented and not well analyzed. This literature review aims to summarize the available literature on the potential of neonatal organ donation and to analyze published cases of neonatal organ transplantation. A systematic search of the Medline and Cochrane databases yielded 2964 articles, which were screened for eligibility. In total, 86 articles were considered eligible, of which 34 were included in the literature review: 8 articles describing the potential of neonatal organ donation programs, and 26 articles describing clinical transplantation. Current evidence suggests there is a large pool of potential neonatal organ donors. In contrast, the literature on neonatal organ donor utilization is sparse. However, case series of successful kidney, heart, liver, hepatocyte, and multivisceral transplantation using organs from neonatal donors are summarized. Although good posttransplant organ function was achieved, the use of neonatal organs is associated with increased risk of thrombosis in both kidney and liver transplantation. Neonatal organ donation is a promising alternative for expanding the current donor pool. Experience is limited, but reported patient and graft survival are acceptable and more research on the subject is warranted.

En Bloc Kidney Transplantation: A Retrospective Study of an 18-year Experience in a Single Institution

Background

Renal transplantation is facing a shortage of grafts. En bloc kidney transplantation (EBKT) from pediatric donors could increase the number of available grafts.

Objective

To describe the surgical technique as well as the long-term functional and morphological results of EBKT.

Design setting and participants

We performed a retrospective study of all the EBKT procedures performed in Lyon between 2002 and 2020. Electronic medical records were checked with an analysis of demographics, and peri- and postoperative results.

Outcome measurements and statistical analysis

A descriptive analysis of donor and recipient characteristics, perioperative data, complications, and renal function was performed.

Results and limitations

Between 2002 and 2020, 21 EBKT procedures were performed. Donors had a mean weight of 8.6 kg and a mean age of 12 mo, with a mean cold ischemia time of 11 h and 30 min. Receivers had a mean age of 30 yr and a body mass index of 20. The mean follow-up time was 62 mo, with patient survival of 100% and graft survival of 95%. There were 13 reinterventions comprising one early unilateral transplantectomy for thrombosis. Renal function was excellent, and the morphological findings described an important growth in size in the first 2 yr before attaining the adult size. This study's limitations include its retrospective nature and a small number of participants.

Conclusions

The present study reports excellent results with EBKT and supports the pursuit and spread of this technique.

Patient summary

In this report, we describe the technique and results of en bloc kidney transplantation. We found that results are excellent for renal function and patient survival. We conclude that en bloc kidney transplantation should be considered to increase the number of grafts.

Donor Size Doesn’t Impact En Bloc Kidney Transplant Outcomes: A Single-Center Experience and Review of Literature

Few transplant programs use kidneys from donors with body weight (BW)<10 kg due to higher incidence of vascular and urological complications, and DGF. The purpose of this study was to investigate the non-inferiority of pediatric en bloc kidneys from donors with BW<10 kg. We performed a single-center retrospective analysis of en bloc kidney transplants from pediatric donor cohort (n = 46) from 2003 to 2021 and stratified the outcomes by donor BW (small group, donor BW<10 kg, n = 30; standard group, donor BW<10 kg, n = 16). Graft function, rate of early post-transplant complications, graft and patient survival were analyzed. Complication rates were similar between both groups with 1 case of arterial thrombosis in the smaller group. Overall graft and patient survival rates were similar between the small and the standard group (graft survival—90% vs. 100%, p = 0.09; patient survival—96.7 vs. 100%, p = 0.48). Serum creatinine at 1, 3, 5 years was no different between groups. Reoperation rate was higher in the small group (23.3% vs. 6.25%, p = 0.03). The allograft from small donors could be related to higher reoperation rate in the early post-transplant period, but not associated with lower long-term graft and patient survival.

Donor-Recipient BSA Matching Is Prognostically Significant in Solitary and En Bloc Kidney Transplantation From Pediatric Circulatory Death Donors

Background.

As the rate of early postoperative complications decline after transplant with pediatric donation after circulatory death (DCD) kidneys, attention has shifted to the long-term consequences of donor–recipient (D-R) size disparity given the pernicious systemic effects of inadequate functional nephron mass.

Methods.

We conducted a retrospective cohort study using Organ Procurement and Transplantation Network data for all adult (aged ≥18 y) recipients of pediatric (aged 0–17 y) DCD kidneys in the United States from January 1, 2004 to March 10, 2020.

Results.

DCD pediatric allografts transplanted between D-R pairs with a body surface area (BSA) ratio of 0.10–0.70 carried an increased risk of all-cause graft failure (relative risk [RR], 1.36; 95% confidence interval [CI], 1.10–1.69) and patient death (RR, 1.32; 95% CI, 1.01–1.73) when compared with pairings with a ratio of >0.91. Conversely, similar graft and patient survivals were demonstrated among the >0.70–0.91 and >0.91 cohorts. Furthermore, we found no difference in death-censored graft survival between all groups. Survival analysis revealed improved 10-y patient survival in recipients of en bloc allografts (P = 0.02) compared with recipients of single kidneys with D-R BSA ratios of 0.10–0.70. A similar survival advantage was demonstrated in recipients of solitary allografts with D-R BSA ratios >0.70 compared with the 0.10–0.70 cohort (P = 0.02).

Conclusions.

Inferior patient survival is likely associated with systemic sequelae of insufficient renal functional capacity in size-disparate DCD kidney recipients, which can be overcome by appropriate BSA matching or en bloc transplantation. We therefore suggest that in DCD kidney transplantation, D-R BSA ratios of 0.10–0.70 serve as criteria for en bloc allocation or alternative recipient selection to optimize the D-R BSA ratio to >0.70.

Transplantation of En Bloc Pediatric Kidneys With a Bladder Segment Patch After a Complex Vascular Reconstruction: A Case Report

BACKGROUND

En bloc pediatric kidney (EBPK) allografts represent one potential solution to increase the number of organs available in the donor pool, thus facilitating transplantation of kidneys from young donors into adult recipients. However, EBPK transplantation has been traditionally considered suboptimal because of concerns for perioperative complications.

METHODS

An extensive reconstruction and successful transplantation of an EBPK allograft using same pediatric donor vascular grafts and a bladder patch aiming to avoid postoperative complications is presented in this report.

RESULTS

The warm ischemia time was 25 minutes. No surgical drainage or ureteral stent were used. Postoperative Doppler ultrasound showed laminar blood flow and normal parameters in both the external iliac and graft arteries, no collections, and no signs of obstructive uropathy. The patient had an uneventful recovery showing a creatinine level of 0.86 mg/dL and 0.85 mg/dL at 1 month and 3 months, respectively.

CONCLUSIONS

A refined back-table reconstruction of these allografts is crucial to avoid mishaps in the postoperative period.

Transplantation of 2-Month-Old En Bloc Pediatric Kidneys After a Complex Vascular Reconstruction - Traveling 2500 Miles to Get Transplanted: A Case Report

BACKGROUND En bloc pediatric kidneys (EBPK) are one potential solution to increase the number of organs available in the donor community, thus promoting transplantation of these allografts into adult recipients. However, EBPK transplantation has been traditionally considered suboptimal due to concerns for perioperative complications, mainly vascular thrombosis. We report an en bloc kidney transplantation using vascular grafts from another deceased donor to extend the EBPK aorta and vena cava and create a tension-free anastomosis with recipient external iliac vessels. CASE REPORT A pair of 2-month-old female en bloc kidneys weighting 6 kg were transplanted to a 30-year-old adult male. Prolonged cold ischemic time (CIT) was related to high refusal rate and long travel from Nevada to Miami. Prior to transplantation, the EBPK were connected to the LifePort Renal Preservation Machine® and deemed transplantable only after showing a significant improvement in perfusion parameters. Back-table reconstruction was conducted through an end-to-end anastomosis between an adult deceased donor common iliac artery and vein grafts to the inferior vena cava and aortic distal ends, respectively. The patient displayed immediate graft function (IGF) without any postoperative complications, showing a creatinine of 1.5 mg/dl at 4-month follow-up. CONCLUSIONS Use of renal preservation machine (RPM) and refined back-table reconstruction of these allografts are important tools to improve the significant discard rate and improve outcomes of EBPK.

Short- and Long-term Outcomes of Kidney Transplants From Very Small (≤15 kg) Pediatric Donors With Acute Kidney Injury

BACKGROUND

Kidneys from small deceased pediatric donors with acute kidney injury (AKI) are commonly discarded owing to transplant centers' concerns regarding potentially inferior short- and long-term posttransplant outcomes.

METHODS

We retrospectively analyzed our center's en bloc kidney transplants performed from November 2007 to January 2015 from donors ≤15 kg into adult recipients (≥18 y). We pair-matched grafts from 27 consecutive donors with AKI versus 27 without AKI for donor weight, donation after circulatory death status, and preservation time.

RESULTS

For AKI versus non-AKI donors, median weight was 7.5 versus 7.1 kg; terminal creatinine was 1.7 (range, 1.1-3.3) versus 0.3 mg/dL (0.1-0.9). Early graft loss rate from thrombosis or primary nonfunction was 11% for both groups. Delayed graft function rate was higher for AKI (52%) versus non-AKI (15%) grafts (P = 0.004). Median estimated glomerular filtration rate was lower for AKI recipients only at 1 and 3 months (P < 0.03). Graft survival (death-censored) at 8 years was 78% for AKI versus 77% for non-AKI grafts. Late proteinuria rates for AKI versus non-AKI recipients with >4 years follow-up were not significantly different.

CONCLUSIONS

Small pediatric donor AKI impacted early posttransplant kidney graft function, but did not increase risk for early graft loss and decreased long-term function. The presently high nonutilization rates for en bloc kidney grafts from very small pediatric donors with AKI appear therefore unjustified. Based on the outcomes of the present study, we infer that the reluctance to transplant single kidneys from larger pediatric donors with AKI lacks a rational basis as well. Our findings warrant further prospective study and confirmation in larger study cohorts.

Kidney Transplantation From a 5-Day-Old Donor With a Single Functioning Kidney

Kidney transplant restores renal function in eligible patients with end-stage renal failure who require renal replacement therapy. There remains a significant disparity between the demand and supply of suitable kidneys for transplant. In recent years, pediatric donors have formed an important area for expansion of the donor pool. However, neonatal donation (< 28 days) remains an underutilized resource. We describe a case of en bloc kidney transplant from a 5-day-old donor after circulatory death into an adult recipient. One kidney thrombosed almost immediately, leaving a single 4.5-cm, poorly functioning kidney. Eighteen months after transplant, the recipient has shown good function with the estimated glomerular filtration rate continuing to improve. This case demonstrates that a single neonatal kidney can grow and adapt to provide adequate renal function in an adult. This experience suggests that a single kidney from a neonate can sustain renal function in adults, and every effort should be made to maximize their use in transplant.

Paediatric kidney transplants from donors aged 1 year and under: an analysis of the Australian and New Zealand Dialysis and Transplant Registry from 1963 to 2018

Kidneys from very small donors have the potential to significantly expand the donor pool. We describe the collective experience of transplantation using kidneys from donors aged ≤1 year in Australian and New Zealand. The ANZDATA registry was analysed on all deceased donor kidney transplants from donors aged ≤1 year. We compared recipient characteristics and outcomes between 1963-1999 and 2000-2018. From 1963 to 1999, 16 transplants were performed [9 (56%) adults, 7 (44%) children]. Death-censored graft survival was 50% and 43% at 1 and 5 years, respectively. Patient survival was 90% and 87% at 1 and 5 years, respectively. From 2000 to 2018, 26 transplants were performed [25 (96%) adults, 1 (4%) children]. Mean creatinine was 73 µmol/l ±49.1 at 5 years. Death-censored graft survival was 85% at 1 and 5 years. Patient survival was 100% at 1 and 5 years. Thrombosis was the cause of graft loss in 12% of recipients in the first era from 1963 to 1999, and 8% of recipients in the second era from 2000 to 2018. We advocate the judicious use of these small paediatric grafts from donors ≤1 year old. Optimal selection of donor and recipients may lead to greater acceptance and success of transplantation from very young donors.

Urologic complications after transplantation of 225 en bloc kidneys from small pediatric donors ≤20 kg: Incidence, management, and impact on graft survival

Pediatric en bloc kidney transplants (EBKs) from small deceased pediatric donors are associated with increased early graft loss and morbidity. Yet, urologic complications post-EBK and their potential impact on graft survival have not been systematically studied. We retrospectively studied urological complications requiring intervention for 225 EBKs performed at our center January 2005 to September 2017 from donors ≤20 kg into recipients ≥18 years. Overall ureteral complication incidence after EBK was 9.8% (n = 22) (12% vs 2% for EBK donors < 10 vs ≥ 10 kg, respectively [P = .031]). The most common post-EBK urologic complication was a stricture (55%), followed by urine leak (41%). In all, 95% of all urologic complications occurred early within 5 months posttransplant (median, 138 days). Urologic complications could be successfully managed nonoperatively in 50% of all cases and had no impact on graft or patient survival. In summary, urologic complications after EBK were common, associated with lower donor weights, occurred early posttransplant, and were often amenable to nonoperative treatment, without adversely affecting survival. We conclude that the higher urologic complication rate after EBK (1) should not prevent increased utilization of small pediatric donor en bloc kidneys for properly selected recipients, and (2) warrants specific discussion with EBK recipients during the preoperative consent process.

Transplantation of a single kidney from pediatric donors less than 10 kg to children with poor access to transplantation: a two-year outcome analysis

Background

Access to kidney transplantation by uremic children is very limited due to the lack of donors in many countries. We sought to explore small pediatric kidney donors as a strategy to provide transplant opportunities for uremic children.

Methods

A total of 56 cases of single pediatric kidney transplantation and 26 cases of en bloc kidney transplantation from pediatric donors with body weight (BW) less than 10 kg were performed in two transplant centers in China and the transplant outcomes were retrospectively analyzed.

Results

The 1-year and 2-year death-censored graft survival in the en bloc kidney transplantation (KTx) group was inferior to that in the single KTx group. Subgroup analysis of the single KTx group found that the 1-year and 2-year death-censored graft survival in the group where the donor BW was between 5 and 10 kg was 97.7 and 90.0%, respectively. However, graft survival was significantly decreased when donor BW was ≤5 kg (p < 0.01), mainly because of the higher rate of thrombosis (p = 0.035). In the single KTx group, the graft length was increased from 6.7 cm at day 7 to 10.5 cm at 36 months posttransplant. The estimated glomerular filtration rate increased up to 24 months posttransplant. Delayed graft function and urethral complications were more common in the group with BW was ≤5 kg.

Conclusions

Our study suggests that single kidney transplantation from donors weighing over 5 kg to pediatric recipients is a feasible option for children with poor access to transplantation.

Non-standard criteria donors in pediatric kidney transplantation

KT remains the treatment of choice for ESRD in children. However, the demand for kidney transplants continues to outstrip supply, even in the pediatric scenario. We reviewed the applicability of nonSCDs for pediatric KT. There is a lack of studies analyzing this modality among pediatric donors and recipients, where most conclusions are based on predictions from adult data. Nevertheless, marginal donors might be a reasonable option in selected cases. For example, the use of older LDs is an acceptable option, with outcomes comparable to SCDs. Organs donated after cardiac death represent another possibility, albeit with logistic, ethical, and legal limitations in some countries. AKI donors also constitute an option in special situations, although there are no pediatric data on these transplants. Likewise, there are no data on the use of expanded criteria donors in pediatric patients, but this appears not to be a good option, considering the compromised long-term survival.