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 transplant from donors <15 kg: An excellent approach to expand the pediatric deceased donor pool

INTRODUCTION

Most kidneys from small pediatric donors are transplanted to adult recipients because of the perceived risk of surgical complications and graft thrombosis. In this study, we aim to demonstrate our favorable outcomes in transplanting pediatric kidneys from donors <15 k into pediatric recipients.

METHODS

This study retrospectively analyzes the outcomes of seven pediatric recipients of en block kidney transplants from pediatric donors weighing <15 kg performed at King Fahad Specialist Hospital-Dammam from December 2014 to January 2018. Baseline characteristics of donors and recipients were collected. The incidences of surgical complication, immediate, and intermediate graft function were the primary outcomes.

RESULTS

The study included seven recipients monitored for a mean duration of 6.86 ± 1.35. Donors' and recipients' mean weights were 7.4 ± 3.2 kg and 20.7 ± 9.2 kg, respectively. Ureteric stricture occurred in one patient. There was a substantial improvement of 1-year estimated glomerular filtration rate (eGFR) compared to the 1-week mark (106.7 ± 26.38 mL/min. 1.73 m2 vs. 63.7 ± 22.92 mL/min/1.73 m2, p = .0069). The observed improvement in renal function persisted at the 5-year mark and during the last follow-up, with eGFR of 70.3 ± 40.7 mL/min/1.73 m2, and 79.8 ± 30.8 mL/min/1.73 m2, respectively. There was also increase of 27.9% in the size of the en bloc kidney observed at the 6 months.

CONCLUSION

In a specialized transplant center with highly skilled surgeons, the utilization of en bloc kidney transplant from donors weighing less than 15 kg is an effective strategy for expanding the donor pool and ensuring favorable graft outcomes.

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.

Complex Vascular Reconstruction of an En Bloc Pediatric Kidney Damaged during Organ Procurement

En bloc pediatric kidney (EBPK) allografts are a potential solution to expand the organ donor pool; however, EBPK transplantation has been traditionally considered suboptimal due to concerns of perioperative vascular and urologic complications. Accidental organ or vasculature injury during harvest is not uncommon; however, this does not necessarily mean that the organ should be discarded. Careful vascular reconstruction can be performed using donor vascular grafts, salvaging the organ without stenosis or thrombosis of the vessels. We report an extensive vascular reconstruction of the right renal artery, aorta, and inferior vena cava of a damaged EBPK allograft using a donor pediatric aorta vascular patch with the goal of avoiding postoperative vascular complications.

Small donors for small recipients - excellent growth and long-term function of single kidney grafts

Small-donor kidneys (≤20 kg donor weight, SDK) are preferably transplanted en bloc in adults. Concerns about thrombotic complications or hyperfiltration hinder their use in children, particularly as single grafts. Low centre experience and donor-to-recipient size are rated critical regarding outcomes. We evaluated SDK transplantation (SDTx) in paediatric recipients at a specialized transplant centre. Between 2008 and 2018, SDTx was performed in 40 children (mean age 5.4 ± 1.4 years, single grafts n = 38, donor weight ≤10 kg: n = 10). Perioperative complications were rare (n = 3), mainly thromboses despite immediate heparinization and resulted in graft loss in one patient. Overall, early and long-term GFR were excellent (76 ± 21 and 100 ± 11 ml/min/1.73 m² , first month and year 5, respectively). Three patients presented with delayed graft function. Graft volume increased significantly (69 ± 38 vs. 111 ± 33 ml within 5 years; P < 0.0001). Patients showed catch-up growth to normal range (SDS for height -2.06 ± 1.6 to -1.60 ± 1.5). Stratification by recipient age and donor weight revealed superior results in young recipients (≤3 years) and ≤10 kg donors, respectively. Outcome of single SDK grafts was excellent. Gain of GFR and graft volume was even higher in patients with very small donor or recipient size, regardless of a reduced donor-to-recipient weight ratio. Therefore, SDTx should be considered favouring small paediatric recipients.

Comparison of Outcomes of Kidney Transplantation From Extremely Low Body Weight ≤5kg Versus Larger Body Weight Pediatric Donors

Background

Kidney transplantation from donors who weigh ≤5 kg is performed at only a few transplant centers owing to the high complication and low graft survival rates associated with this approach.

Methods

We retrospectively compared the results of kidney transplantation at our center between January 2015 and December 2019 based on the following pediatric donor criteria: donor body weight ≤5 kg (n=32), 5 kg< donor weight ≤20 kg (n=143), and donor weight >20 kg (n=110). We also perform subgroup analysis of kidney transplantation outcomes from ≤5 kg donors, using conventional (dual separate and classic en-bloc KTx)/novel (en-bloc KTx with outflow tract) surgical methods and allocating to adult/pediatric recipients.

Results

The death-censored graft survival rates from extremely low body weight ≤5kg at 1 month, and 1, 3, and 5 years were 90.6%, 80.9%, 77.5%, and 73.9%, respectively, which were significantly lower than that from larger body weight pediatric donors. However, the 3-, and 5-year post-transplantation eGFRs were not significantly different between the pediatric and adult recipient group. The thrombosis (18.8%) and urinary leakage (18.8%) rates were significantly higher in the donor weight ≤5 kg group. Compared with 5 kg< donor weight ≤20 kg group, donor weight ≤5kg group was at elevated risk of graft loss due to thrombosis (OR: 13.4) and acute rejection (OR: 6.7). No significant difference on the outcomes of extremely low body weight donor kidney transplantation was observed between adults and pediatric recipients. Urinary leakage rate is significantly lower in the novel operation (8.7%) than in the conventional operation group (44.4%).

Conclusions

Although the outcomes of donor body weight ≤5kg kidney transplantation is inferior to that from donors with large body weight, it can be improved through technical improvement. Donors with body weight ≤5 kg can be considered as an useful source to expand the donor pool.