Outcomes of En Bloc Kidney Transplantation From Pediatric Donors: A Single-Center Experience

The effect of low donor-to-recipient body weight ratio on graft survival after dual kidney transplantation from pediatric deceased donors

BACKGROUND

Dual kidney transplantation (DKT) from small pediatric donors, either en-bloc or split dual kidney transplantation, contributes to mitigating organ scarcity. This study investigates the prognosis of DKT from pediatric deceased donors, and influencing factors.

METHOD

A retrospective study included recipients who underwent DKT from pediatric donors between 2012 and 2022. Recipients were categorized into low mismatch (BWLM, n = 30) and high mismatch (BWHM, n = 10) groups based on donor-recipient weight ratio of 1:10. Outcome encompassed recipient and graft survival, renal function, and adverse events.

RESULT

Forty recipients were included. The average follow-up period was 54.6 months. The 1, 3, and 5-year patient survival were 97.4%, with no significant differences between en-bloc and split dual kidney transplantation or between BWLM and BWHM groups. The graft survival at 1, 3, and 5 years were 89.9%, the graft survival of BWHM group was lower than BWLM group (70% vs 96.7%, p = 0.039). The average eGFR at 1, 3, and 5 years postoperatively were (78.93 ± 25.23), (83.82 ± 32.4), and (85.92 ± 37.08) mL/min/1.73 m2, respectively. The BWHM group also experienced higher rates of graft-related surgical complications (p = 0.006) and urinary tract surgical complications (p = 0.042).

CONCLUSION

DKT from pediatric donors yields favorable outcomes, with similar graft survival and complication rates across surgical subgroups. However, significant donor-recipient weight mismatch, particularly when the ratio is less than 1:10, may contribute to increased surgical complications and poorer graft survival. Efforts to minimize extreme weight mismatch are recommended to optimize outcomes.

En-bloc kidney transplants from very small pediatric donors: a propensity score matched analysis

Background

Kidneys from brain-death small pediatric donors ≤2 years are still classified as marginal organs. Herein, we analyse the outcomes following en-bloc kidney transplantation (EBKT) from pediatric donors ≤2 years into adult recipients compared to standard criteria donor kidney transplant recipients (SKTs).

Methods

A retrospective single center analysis of a prospectively collected and auditable database identified six EBKTs and 75 SKTs between January 2015 and June 2017. Propensity score matching minimized selection bias.

Results

After a median follow-up of 74 months, five-year patient and graft survival were 100%, each in the EBKTs group. Following SKTs, the five-year patient survival rate was 94.7%, likewise death-censored graft survival reached 94.7%. Two EBKT cases experienced unilateral arterial graft thrombosis requiring unilateral nephrectomy, with full recovery and good kidney function. At hospital discharge, recipients of EBKTs showed decreased eGFR compared to SKTs, however, from 3 months onward this reversed and following a median follow-up of 74 months the median eGFR was twice as high after EBKT compared to SKT (107 ml/min/1.73m2 vs. 52 ml/min/1.73m2, p < 0.001). These favourable results persist in the PSM analysis.

Conclusion

EBKTs from very small pediatric donors show excellent long-term kidney function. The higher incidence of postoperative complications does not translate into poorer mid-term patient and graft survival.

Technical Feasibility of Renal Artery Embolization on a Transplanted Kidney Due to Intractable Unilateral Hydronephrosis After En Bloc Kidney Transplantation: Case Report

INTRODUCTION

En bloc kidney transplantation (EBKT) is a technique used to transplant pediatric kidneys to adult recipients, but can lead to certain complications seldom found in single-kidney transplantation. We report a case of renal artery embolization after EBKT due to intractable unilateral hydronephrosis and highlight the technical details and challenges of the procedure.

CASE

An 18-year-old female with MELAS syndrome underwent EBKT from a 10-month-old male baby. Two months later, the patient developed unilateral hydronephrosis and recurrent urinary tract infections, which was intractable to conventional therapy. Therefore, we underwent embolization of the problematic transplanted left kidney. Owing to the complicated anatomy and multiple angulations, multiple microcatheters, wires and support catheters were needed to select the renal arteries. Repeated procedures were required due to remnant flow from small branches and accessory renal arteries that were not easily visualized by conventional angiography, which were eventually detected by adjunctive use of 3-dimensional rotational angiography.

CONCLUSIONS

Selective renal artery embolization after EBKT is challenging due to the short renal artery length and multiple angulations, yet it can still be performed safely and effectively by use of meticulous catheter-wire interactions and adjunctive intraoperative imaging techniques to delineate the precise anatomy of the target arteries.

CLINICAL IMPACT

Selective renal artery embolization, which is less invasive than nephrectomy, can be considered if the culprit kidney must inevitably be sacrificed in en bloc kidney transplantation.

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.

Small Split Pediatric Kidneys to Expand the Donor Pool: An Analysis of Scientific Registry of Transplant Recipients (SRTR) Data

BACKGROUND

Increased use of pediatric deceased donor kidneys could enlarge the deceased donor kidney pool. Kidney transplant outcomes from small pediatric donors were compared with those from ideal kidney (IK) and expanded criteria kidney (ECK) donors to understand the optimal use of pediatric donor kidneys.

METHODS

Kaplan-Meier analyses compared long-term patient and death-censored graft survival of en bloc kidney (EBK) and split kidney (SpK) transplants from small pediatric donors (aged ≤8 y and weight <30 kg) with those from IK and ECK. Posttransplant serum creatinine) was compared among these cohorts. Deceased donor kidney disposition was determined from small pediatric donors with ≥1 organ transplanted.

RESULTS

Patient and death-censored graft survival were similar among recipients of IK, EBK, and SpK transplants, and were superior to those of recipients of ECK. EBK and SpK transplants from donors 5-30 kg had first-year graft loss similar to ECK. Long-term graft survival and serum creatinine with kidneys from SpK donors >10 kg were better than that with ECK donors. About 3901 transplants were performed from 3660 pediatric donors (53% yield).

CONCLUSIONS

Pediatric kidneys can augment the kidney donor pool and should not be considered ECK. If 90% of kidneys from donors (aged ≤8 y and weight <30 kg) with ≥1 organ transplanted been used (as SpK when >10 kg) an additional 159 kidney transplants per year could have been performed. Expanding the use of pediatric kidneys should be further explored by the transplant community.

Transplantation of pediatric renal allografts from donors less than 10 kg

Few transplant programs use kidneys from donors with body weight (BW) < 10 kg. We hypothesized that pediatric en bloc transplants from donors with BW < 10 kg would provide similar transplant outcomes to larger grafts. All pediatric en bloc renal transplants performed at our center between 2001 and 2017 were reviewed (N = 28). Data were stratified by smaller (donor BW < 10 kg; n = 11) or larger donors (BW > 10 kg; n = 17). Renal volume was assessed during follow-up with ultrasound. Demographic characteristics were similar between the 2 groups of recipients. After mean follow-up of 44 months (smaller donors) and 124 months (larger donors), graft and patient outcomes were similar between groups. Serum creatinine at 1, 3, and 5 years was no different between groups. At 1 day posttransplant, mean total renal volume in the smaller donors was 28 ± 9 mm³ vs 45 ± 12 mm³ (P < .01). By 3 weeks, it was 53 ± 19 mm³ (smaller donors) versus 73 ± 19 mm³ (larger donors) (P = NS). Complication rates were similar between both groups with 1 case of venous thrombosis in the smaller group. With experience, outcomes are equivalent to those from larger pediatric donors.

Outcomes of single kidney transplantation from pediatric donors: A single-center experience

Kidneys from pDDs are increasingly used to narrow the huge gap between incremental demand and static supply. However, there is still controversy on the clinical outcome of SKT from pDDs. We conducted a retrospective cohort study of 452 adult recipients in our center between March 2012 and February 2017. Outcomes of 3 groups, transplants with organs from pDDs (n=50), aDDs (n=207), and LDs (n=195), were compared. The mean age and weight of pDDs were 8.98 years (range 8 months-17 years) and 30.05 kg (range 8.2-55 kg), respectively. There was no difference in 1-year (96.0%, 98.1%, and 99.0%, respectively, P=.277) and 3-year patient survival (96.0%, 98.1%, and 99.0%, respectively, P=.277) or in 1-year (96.0%, 96.6%, and 98.5%, P=.307) and 3-year (96.0%, 96.6% and 97.9%, P=.437) graft survival. SCr, eGFR, and allograft size were similar among the 3 groups at 6th month post-transplant and thereafter. Incidence of DGF was higher in patients of the aDD group than those in the pDD group (22.7% vs 10.0%, P<.001), but there was no difference in AR and infection. SKT from pDDs to adult recipients is effective and safe with acceptable outcomes, and it will be a promising expansion to the donor pool.