Pediatric en bloc kidney transplantation to adult recipients: more than suboptimal? Transplantation. 2010;90:248-254. [PMID: 20548262 DOI: 10.1097/tp.0b013e3181e641f8]

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.

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.

Favorable Outcome After Single-kidney Transplantation From Small Donors in Children: A Match-controlled CERTAIN Registry Study

BACKGROUND

Kidney transplantation (KTx) from small donors is associated with inferior graft survival in registry studies, whereas single-center studies show favorable results.

METHODS

We compared 175 pediatric KTx from small donors ≤20 kg (SDKTx) with 170 age-matched recipients from adult donors (ADKTx) from 20 centers within the Cooperative European Paediatric Renal Transplant Initiative registry. Graft survival and estimated glomerular filtration rate (eGFR) were analyzed by Cox regression and mixed models. Detailed data on surgical and medical management were tested for association with graft survival.

RESULTS

One-year graft survival was lower after SDKTx compared with ADKTx (90.9% versus 96.5%; odds ratio of graft loss, 2.92; 95% confidence interval [CI], 1.10-7.80; P  = 0.032), but 5-y graft survival was comparable (90.9% versus 92.7%; adjusted hazard ratio of graft loss 1.9; 95% CI, 0.85-4.25; P  = 0.119). SDKTx recipients had an annual eGFR increase of 8.7 ± 6.2 mL/min/1.73 m² compared with a decrease of 6.9 ± 5.7 mL/min/1.73 m² in ADKTx recipients resulting in a superior 5-y eGFR (80.5 ± 25.5 in SDKTx versus 65.7 ± 23.1 mL/min/1.73 m² in ADKTx; P  = 0.008). At 3 y posttransplant, eGFR after single SDKTx was lower than after en bloc SDKTx (86.6 ± 20.4 versus 104.6 ± 35.9; P  = 0.043) but superior to ADKTx (68.1 ± 23.9 mL/min/1.73 m²). Single-kidney SDKTx recipients had a lower rate of hypertension at 3 y than ADKTx recipients (40.0% versus 64.7%; P  = 0.008).

CONCLUSIONS

Compared with ADKTx, 5-y graft function is superior in SDKTx and graft survival is similar, even when performed as single KTx. Utilizing small donor organs, preferably as single kidneys in experienced centers, is a viable option to increase the donor pool for pediatric recipients.

En bloc kidney transplantation from pediatric donors to teenage recipients: Two case reports

Introduction

Since the implementation of the new selection criteria in 2018, kidney donations from pediatric patients have been prioritized for pediatric recipients and kidney donations from pediatric donors have increased in Japan. Herein, we present two cases of en bloc kidney transplantation.

Case presentation

Case 1: A 19-year-old male patient who had been on hemodialysis for 5 years due to end-stage renal disease. After brain death, a graft from a 5-year-old boy was transplanted into the right iliac fossa. Case 2: A 19-year-old male patient, who had previously undergone a living kidney transplantation at the age of 3, received a secondary cadaveric kidney transplantation in the left iliac fossa. The graft was procured from a 17-month-old girl following cardiac death.

Conclusion

This report will help surgeons perform en bloc kidney transplantation in the growing number of pediatric kidney donations, such as those in Japan.

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.

Successful transplantation of four kidney grafts from two small pediatric donors with anuric acute renal failure into adult recipients

BACKGROUND

Kidneys from infants with anuric acute kidney injury (AKI) only rarely get accepted for transplantation despite encouraging data that such kidneys can have very good long-term outcome.

METHODS

We report the transplantation of four kidney grafts from two pediatric donors (3 and 4 years) with anuric acute kidney injury as single kidneys into four adult recipients.

RESULTS

All grafts gained function within 14 days posttransplantation, only one recipient needed dialysis after transplantation. None of the recipients suffered from surgical complications. One month after transplantation, all recipients were free of dialysis. Estimated glomerular filtration rates (eGFR) 3 months after transplantation were 37, 40, 50, and 83 mL/min/1.73 m2 . eGFR increased further through month 6, reaching 45, 50, 58, and 89 mL/min/1.73 m2 .

CONCLUSION

These cases highlight the feasibility of successful transplantation of single pediatric kidney grafts into adult recipients despite anuric AKI of the donor.

Youngest en-bloc kidney transplant recipient in India: defying the barriers and challenges with teamwork

We received a call from a transplant coordinator about the availability of a consented deceased donor. En-bloc kidneys with the aorta and IVC (inferior vena cava) were harvested from a toddler weighing 8 kg. The recipient was of early childhood weighing 14 kg who had been on haemodialysis for the last 3 years for end-stage kidney disease. He received anti-thymocyte globulin as an induction immunosuppressant. The kidneys were transplanted en bloc in the right lower quadrant retroperitoneal region; an anastomosis was performed to the recipient's aorta and IVC, and two separate neocystoureterostomies were created. His serum creatinine reached 0.5 mg/dL on the seventh postoperative day, following a few days of delayed graft function. In this study, we describe the surgical and non-surgical challenges that we faced while performing en-bloc kidney transplant to the youngest recipient and how a multidisciplinary team approach helped us overcome them.

Kidney Volume Growth and Kidney Function of en bloc Pediatric Kidney Transplants: A Case Series

Rationale & Objective

Kidney transplant is a mainstay of kidney replacement therapy. Given a continued shortage of organs, pediatric en bloc kidney transplants may have substantial utility. We present our long-term experience with en bloc transplants from donors aged 3 to 60 months, including changes in kidney function and kidney volume over time as well as biopsy findings.

Study Design

Case series.

Setting & Participants

Medical records from a single academic medical center were reviewed. Aggregate serial volumes of 22 en bloc kidney allografts from 2010 to 2017 were assessed at the time of transplant and during follow-up. Estimated glomerular filtration rates (eGFR) were described at 3 months after transplant (baseline) as well as over the ensuing 3 years. Interstitial fibrosis, a finding determined by histopathologic review, which results from an accumulation of collagen that is produced from mediators produced from complex interaction of multiple inflammatory cells, was assessed on 20 protocol biopsies obtained from 6 patients, of which 4 patients had 4 biopsies and 2 patients had 1 biopsy.

Results

Kidney volume was obtained from 51 ultrasound studies performed up to 74 months after transplant. Kidney volume generally increased and eGFR rose over time after the transplant, with 23% patients achieving an eGFR of >75 mL/min/1.73 m² at 3 months posttransplant. The remainder achieved an eGFR >75 mL/min/1.73 m² over the ensuing 3 years. Interstitial fibrosis noted on biopsies appeared to foreshadow an eventual reduction in kidney volume.

Limitations

Retrospective study, possible selection bias, single-center experience.

Conclusions

The kidney en bloc allografts increased in size after transplantation, with associated improved kidney function. Chronic damage to the graft, from interstitial fibrosis and tubular atrophy, resulted in long-term reduction in kidney volume.

Excellent Clinical Long-Term Outcomes of Kidney Transplantation From Small Pediatric Donors (Age ≤ 5 Years) Despite Early Hyperfiltration Injury

Background:

The use of small pediatric donors (age ≤ 5 years and body weight < 20kg) for adult transplant recipients is still regarded controversially in terms of early complications, long-term outcomes, and development of hyperfiltration injury due to body size mismatch.

Objective:

To investigate long-term outcomes of adult renal allograft recipients receiving a kidney from small pediatric donor (SPD) in terms of kidney function and early features of hyperfiltration injury such as histological changes and proteinuria.

Design:

Retrospective, single center study.

Settings:

Transplant center of the University Hospital of Basel, Switzerland.

Patients:

Adult renal allograft recipients receiving a kidney from a small pediatric donor at our center between 2005 and 2017.

Methods:

The outcome of 47 transplants from SPD were compared with 153 kidney transplants from deceased-standard criteria donors (SCD) occurring during the same time period. Incidence of clinical signs of hyperfiltration injury (eg, proteinuria) was investigated. According to our policy, surveillance biopsies were taken at 3 and 6 months post-transplant and were evaluated in terms of signs of hyperfiltration injury.

Results:

At a median follow-up of 2.3 years post-transplant, death-censored graft survival of SPD was comparable to transplants from SCD (94% vs 93%; P = .54). Furthermore, allograft function at last follow-up (estimated glomerular filtration rate–Modification of Diet in Renal Disease) was significantly higher in pediatric transplant (80 vs 55 ml/min/1.73 m2, P = .002). We found histological signs of early hyperfiltration injury in 55% of SPD. There was an equally low proteinuria in both groups during follow-up.

Limitations:

It is a single center and retrospective observational study with small sample size. The outcomes were investigated in a well-selected population of recipients with low body mass index, low immunological risk, and well-controlled hypertension and was not compared with equal selected group of recipients.

Conclusions:

Early histological and clinical signs of hyperfiltration injury in SPD is frequent. Despite the hyperfiltration injury, there is an equal allograft survival and even superior allograft function in SPD compared with SCD during follow-up. This observation supports the concept of high adaptive capacity of pediatric donor kidneys.

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.

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.

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.

Pediatric Donor Glomerulopathy Is a Possible Cause of Abnormal Urinalysis in Adults Receiving Small Pediatric Donor Kidneys

Background.

Reports about prognosis of adults receiving small pediatric-donor kidneys (PDK) as compared to those receiving elder pediatric or adult donor kidneys (ADKs) are controversial. This study aimed to examine the outcomes of adults receiving small PDK and possible prognostic factors.

Methods.

The records of adults who received kidneys from donors < 10 years old at our center from July 1, 2011 to June 30, 2018 were reviewed.

Results.

A total of 121 adults were small PDK recipients. Twenty-three patients received 29 biopsies or nephrectomy between 6 and 896 days posttransplantation days. Seven patients (30.4%) had pediatric donor glomerulopathy (PDG), which developed from 113 to 615 days posttransplantation. The incidence of proteinuria and hematuria was significantly higher in the PDG group. The characteristic pathological finding in PDG was irregular lamination and splintering of the glomerular basement membrane (GBM). Donor age, donor weight, and donor kidney volume were significantly less in PDG cases compared with the non-PDG cases. For the risk factors of PDG, increasing urinary RBC count during follow-up was an independent predictor, while increasing donor age and body weight were protective factors. PDG was not a significant risk factor for Scr increasing of PDKs.

Conclusions.

PDG is a potential cause of abnormal urinalysis in adults receiving small PDKs. The pathological characteristic change of PDG is splitting and lamination of GBM. Persistent hematuria after transplantation in recipients of PDK is a predictor of PDG development.

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.

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.

Utilisation of small paediatric donor kidneys for transplantation

With the increasing need for kidney transplantation in the paediatric population and changing donor demographics, children without a living donor option will potentially be offered an adult deceased donor transplant of marginal quality. Given the importance of long-term graft survival for paediatric recipients, consideration is now being given to kidneys from small paediatric donors (SPDs). There exist a lack of consensus and a reluctance amongst some centres in transplanting SPDs due to high surgical complication rates, graft loss and concerns regarding low nephron mass and long-term function. The aim of this review is to examine and present the evidence base regarding the transplantation of these organs. The literature in both the paediatric and adult renal transplant fields, as well as recent relevant conference proceedings, is reviewed. We discuss the surgical techniques, long-term graft function and rates of complications following transplantation of SPDs. We compare graft survival of SPDs to adult deceased donors and consider the use of small paediatric donors after circulatory death (DCD) organs. In conclusion, evidence is presented that may refute historically held paradigms regarding the transplantation of SPDs in paediatric recipients, thereby potentially allowing significant expansion of the donor pool.

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.

Unusual Bilateral Renal Parenchymal Urine Leak After Pediatric En Bloc Kidney Transplantation: First Case Study Report

Kidney transplantation is usually the best course of treatment for patients with end-stage renal disease. En bloc kidney transplantation (EBKT) is a surgical treatment option that increases available donor organs with excellent graft survival for patients with end-stage renal disease. Herein, we report a case of an unusual bilateral renal parenchymal urine leak after EBKT leading to removal of both moieties of the EBKT. This unfortunate complication after EBKT, to our knowledge, is the only reported of its kind. We explore the possible causes of the bilateral parenchymal urine leaks and suggest preventive strategies to avoid urological complications after EBKT.

Successful Repair of Bilateral Ureteral Stricture 3 Years after En Bloc Kidney Transplant: A Case Report

En bloc kidney transplants of small pediatric kidneys into adult recipients have been shown to have outcomes similar to transplants from standard adult deceased donors. Here, we report a 27-year-old male patient with successful repair of bilateral ureteral stricture 3 years after en bloc kidney transplant at the Shahid Modarres Hospital (Tehran, Iran). The patient received an en bloc deceased kidney donation from a 9-month-old infant. An end-to-end anastomosis of the aorta to the internal iliac artery and an end-to-side external iliac vein anastomosis to vena cava were performed. At an outpatient visit about 2.5 years later, the patient showed increasing levels of creatinine from 1.1 to 1.8 mg/dL compared with measurements at his 2-month visit. A computed tomography scan performed without any contrast agent at that time confirmed the existence of hydronephrosis in both the medial and lateral kidneys. A nephrostography showed a ureteral stricture. Because endoscopic surgery for ureteral dilatation was not successful, the decision was made to perform ureteral repair by the open surgical technique. The short length of the ureters resulted in the lateral renal pelvis being anastomosed to the bladder by flap (Boari flap). The ureter of the patient's native kidney was transected in the middle portion, and the distal ureter was anastomosed to the medial renal pelvis using the end-to-end method. Here, we showed that, despite limited experiences with pediatric donors, en bloc kidney transplant can be performed under the guidance of experienced surgical techniques and precise postoperative follow-up.

Venous anastomosis by piggyback technique to avoid twisting of the pediatric en bloc kidney grafts

This is the first report of using piggyback technique for the venous anastomosis in two pediatric recipients of small en bloc kidneys, which was found to be effective to avoid twisting of the grafts and vessels. The donors were aged 2 and 3 years with a body weight of 17 and 20 kg. The recipient age was 14 and 16 years with a body weight of 42 and 54 kg. The implantation was done extraperitoneally in the right iliac fossa. The donor's inferior vena cava was anastomosed to the recipient's distal caval vein side-to-side using 6-0 polydioxanone running suture as the piggyback technique, initially dealing with the short vena cava graft in the first case. At the end of the operation, the kidneys were positioned allowing the lateral aspect of each renal unit to face anteriorly as "closing the book." The cold ischemia time was 895 and 820 minutes, respectively. No vascular complication was observed postoperatively. The patients were discharged on POD 16 and POD 21 with an eGFR of 94 and 102 mL/min/1.73 m², respectively. The graft function is stable during the 5- and 7-month follow-up.

En bloc kidney transplantation from a 24 month-old donor to an adult recipient: case presentation and literature review

Paediatric kidney transplantation into adult recipients is a well-recognised technique. However, there are different opinions regarding two methods of transplantation. These two opinions are single kidney transplantation (SKT) and en bloc kidney transplantation (EBKT) from donors up to 20 kg. We are reporting the first successful en bloc kidney transplantation from a small, paediatric donor into an adult recipient in our institution and discussing the appropriate recent literature regarding possible concerns using this technique. Despite the fact that paediatric donors are uncommon and surgical experiences are limited, en bloc kidney transplantation can be performed successfully and could be used to expand the donor pool.

En Bloc Cadaver Kidney Transplantation From a 9-Month-Old Donor to an Adult Recipient: Maturation of Glomerular Size and Podocyte in the Recipient

BACKGROUND

Favorable outcomes of en bloc pediatric donor kidney transplantation to adult recipients are attributed primarily to grafting of twice the nephron mass of a single kidney.

METHODS

The kidneys of a 9-month-old male infant were transplanted en bloc in a 56-year-old man. Biopsies were performed 1 hour postreperfusion, 6 months and 3.5 years posttransplant.

RESULTS

Warm and cold ischemia times were 21 and 426 minutes, respectively. The recipient was released from hemodialysis 10 days posttransplant and discharged 91 days posttransplant when serum creatinine was 0.9 mg/dL. At 4 years and 9 months posttransplant, serum creatinine was 1.0 mg/dL, and estimated glomerular filtration rate was 58.0 mL/min per 1.73 m². The grafts increased in size until they reached adult size by 3 months posttransplant. The glomerular area and volume, respectively, increased from 5.9 × 10³ μm² and 0.34 × 10⁶ μm³ at 1 hour postreperfusion to 14.9 × 10³ μm² and 1.27 × 10⁶ μm³ at 3.5 years posttransplant, both of which were less than half of adult size. At 1 hour postreperfusion, podocytes were structurally immature. At 6 months posttransplant, podocyte immaturity was still evident. At 3.5 years posttransplant, podocytes were mature.

CONCLUSIONS

These findings suggest that podocytes and glomerular size of pediatric donor kidneys can continue to mature in adult recipients at rates appropriate for donor age when transplanted en bloc. The maturational levels of podocytes and glomeruli may also be a factor involved in favorable outcomes of en bloc pediatric donor kidney transplantation.

Comparable Survival of En Bloc versus Standard Donor Kidney Transplants in Children

OBJECTIVE

To determine whether renal transplantation survival is similar in children receiving pediatric en bloc kidneys compared with those receiving standard deceased donor kidneys.

STUDY DESIGN

We compared time to allograft failure and estimated glomerular filtration rate (eGFR) in pediatric recipients of en bloc and standard criteria deceased donor renal transplants using Organ Procurement and Transplantation Network data for 2000-2013. Cox regression analysis was used to compare time to allograft failure, and the Student t test was used to compare eGFR.

RESULTS

A total of 6882 recipients met the study inclusion criteria; 1.8% received an en bloc transplant. The adjusted hazard for allograft failure was similar for recipients of en bloc kidneys compared with standard criteria kidneys (hazard ratio, 1.15; 95% CI, 0.83-1.59; P = .41). The median wait time for transplantation was significantly shorter for recipients of en bloc kidneys (157 days vs 208 days; P = .03). Moreover, eGFR was superior for recipients of en bloc kidneys up to 5 years post-transplantation.

CONCLUSION

Transplantation of en bloc pediatric kidneys should be considered a viable option for pediatric recipients and may afford unique benefits by reducing wait times and promoting preservation of graft function.

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

AIM: To compare outcomes between single and dual en bloc (EB) kidney transplants (KT) from small pediatric donors.

METHODS: Monocentric nonprospective review of KTs from pediatric donors ≤ 5 years of age. Dual EB KT was defined as keeping both donor kidneys attached to the inferior vena cava and aorta, which were then used as venous and arterial conduits for the subsequent transplant into a single recipient. Donor age was less useful than either donor weight or kidney size in decision-making for kidney utilization as kidneys from donors < 8 kg or kidneys < 6 cm in length were not transplanted. Post-transplant management strategies were standardized in all patients.

RESULTS: From 2002-2015, 59 KTs were performed including 34 dual EB and 25 single KTs. Mean age of donors (17 mo vs 38 mo, P < 0.001), mean weight (11.0 kg vs 17.4 kg, P = 0.046) and male donors (50% vs 84%, P = 0.01) were lower in the dual EB compared to the single KT group, respectively. Mean cold ischemia time (21 h), kidney donor profile index (KDPI; 73% vs 62%) and levels of serum creatinine (SCr, 0.37 mg/dL vs 0.49 mg/dL, all P = NS) were comparable in the dual EB and single KT groups, respectively. Actuarial graft and patient survival rates at 5-years follow-up were comparable. There was one case of thrombosis resulting in graft loss in each group. Delayed graft function incidence (12% dual EB vs 20% single KT, P = NS) was slightly lower in dual EB KT recipients. Initial duration of hospital stay (mean 5.4 d vs 5.6 d) and the one-year incidences of acute rejection (6% vs 16%), operative complications (3% vs 4%), and major infection were comparable in the dual EB and single KT groups, respectively (all P = NS). Mean 12 mo SCr and abbreviated MDRD levels were 1.17 mg/dL vs 1.35 mg/dL and 72.5 mL/min per 1.73 m²vs 60.5 mL/min per 1.73 m² (both P = NS) in the dual EB and single KT groups, respectively.

CONCLUSION: By transplanting kidneys from young pediatric donors into adult recipients, one can effectively expand the limited donor pool and achieve excellent medium-term outcomes.

Kidney transplantation, bioengineering and regeneration: an originally immunology-based discipline destined to transition towards ad hoc organ manufacturing and repair

Kidney transplantation (KT), as a modality of renal replacement therapy (RRT), has been shown to be both economically and functionally superior to dialysis for the treatment of end-stage renal disease (ESRD). Progress in KT is limited by two major barriers: a) a chronic and burgeoning shortage of transplantable organs and b) the need for chronic immunosuppression following transplantation. Although ground-breaking advances in transplant immunology have improved patient survival and graft durability, a new pathway of innovation is needed in order to overcome current obstacles. Regenerative medicine (RM) holds the potential to shift the paradigm in RRT, through organ bioengineering. Manufactured organs represent a potentially inexhaustible source of transplantable grafts that would bypass the need for immunosuppressive drugs by using autologous cells to repopulate extracellular matrix (ECM) scaffolds. This overview discusses the current status of renal transplantation while reviewing the most promising innovations in RM therapy as applied to RRT.

Identifying potential kidney donors among newborns undergoing circulatory determination of death

BACKGROUND

Over 96,000 patients await kidney transplantation in the United States, and 35,000 more are wait-listed annually. The demand for donor kidneys far outweighs supply, resulting in significant waiting list morbidity and mortality. We sought to identify potential kidney donors among newborns because en bloc kidney transplantation donation after circulatory determination of death (DCDD) may broaden the donor pool.

METHODS

We reviewed discharges from our 84-bed NICU between November 2002 and October 2012 and identified all deaths. The mode of death among potential organ donors (weight ≥ 1.8 kg) was recorded. Patients undergoing withdrawal of life support were further evaluated for DCDD potential. After excluding patients with medical contraindications, those with warm ischemic time (WIT) less than 120 minutes were characterized as potential kidney donors.

RESULTS

There were 11,201 discharges. Of 609 deaths, 359 patients weighed ≥ 1.8 kg and 159 died after planned withdrawal of life support. The exact time of withdrawal could not be determined for 2 patients, and 100 had at least 1 exclusion criterion. Of the remaining patients, 42 to 57 infants were potential en bloc kidney donors depending on acceptance threshold for WIT. Applying a 40% to 70% consent rate range would yield 1.7 to 4 newborn DCDD donors per year.

CONCLUSIONS

A neonatal DCDD kidney program at our institution could provide 2 to 4 paired kidneys for en bloc transplantation each year. Implementing a DCDD kidney donation program in NICUs could add a new source of donors and increase the number of kidneys available for transplantation.

En bloc kidney transplant from an 18-month-old donor to an adult recipient: Case report and literature review

INTRODUCTION

There is an ever-increasing need for organ donations globally. Paediatric kidney transplantation into adult recipients is a well-recognised technique to expand the donor pool. The transplantation can be done either via en bloc kidney transplant (EBKT) or as single kidney transplantation (SKT).

PRESENTATION OF CASE

An EKBT from a 18-month-old (15 kg) male patient was transplanted in a 35-year old, 85 kg male with end stage renal failure (ESRF), secondary to Focal Segmental Glomerulosclerosis (FSGS) on haemodialysis. Post-operative recovery was uneventful. Immuno-suppressant drugs used were tacrolimus, basiliximab and prednisolone. Doppler ultrasound scans performed post-operatively showed normal renal resistive indices in both kidneys. Serum creatinine decreased from 1200 to 170 μmol/L 57 with eGFR improving from 4 to 38 mL/min/1.73 m² at four weeks post-transplant.

DISCUSSION

Given the low incidence of paediatric donors, EBKTs are relatively uncommon and subsequently published series tend to be centre specific with small numbers. The graft survival rates tell us that paediatric kidney donors should not be considered as marginal transplants. The difficulty is in determining when it is more appropriate to perform a paediatric EBKT as opposed to splitting and performing two SKT. Unfortunately there are no widely accepted guidelines to direct clinicians.

CONCLUSION

This case report highlights the first EKBT performed at our institution. The current literature demonstrates that paediatric donors are excellent resources that should be procured whenever available.

Single pediatric kidney transplantation in adult recipients: comparable outcomes with standard-criteria deceased-donor kidney transplantation

BACKGROUND

Single pediatric kidney transplantation (SKT) in adult recipients has traditionally been considered a high risk because of concerns of technical complications leading to poor graft outcomes. The primary goal of this single-center, retrospective analysis was to compare outcomes after SKT to standard-criteria deceased-donor kidney transplantation (SCDKT).

METHODS

We compared outcomes in adult recipients after SKT (n=31; mean donor weight, 27 kg); SCDKT (n=283); pediatric en bloc (n=21), living-donor (n=275), and extended criteria-donor (n=100) kidney transplantations.

RESULTS

The death-censored 5-year graft survival after SKT was significantly superior to SCDKT (81.4% vs. 74.5%, P=0.02). The serum creatinine level at 5 years after transplantation was significantly lower in SKT compared with that in SCDKT (1.2 vs. 1.6 mg/dL, P<0.0001). There was a significantly higher incidence of arterial anastomotic stenosis (6.8% vs. 0.4%, P=0.02) and hydronephrosis (12.9% vs. 5.3%, P=0.02) in the SKT cohort compared with SCDKT. Subgroup analysis of the SKT cohort by donor age less than 5 years vs. 6 to 10 years (mean weight, 16.4 vs. 32.7 kg) revealed no differences in patient or graft survival.

CONCLUSIONS

Despite a higher incidence of posttransplantation vascular and urological complications, long-term graft survival after SKT (in weight-matched pediatric donors and selected adult recipients) was comparable with that after SCDKT. SKT from very small donors (age, ≤5 years) yielded excellent long-term patient and graft survivals. The use of pediatric donor kidneys should be encouraged to address the problem of organ shortage.

Current status of pediatric donor en bloc kidney transplantation to young adult recipients

CONTEXT AND OBJECTIVES

In recent years, despite the increased number of kidney transplants performed in Spain, we observed a gradual increase in waiting lists. The need to increase the number of transplants performed in our centers, forces us to accept as donors patients previously rejected.

ACQUIRING OF EVIDENCE

We performed a systematic review using PubMed of published articles in the last 10 years, that include the words transplant renal en bloque, "en bloc kidney transplantation" or its initials EBKT.

SYNTHESIS OF EVIDENCE

The pediatric donor to adult recipient has been included in the expanded criteria donors group, being rejected nevertheless such donors in most centers. However, in recent published series comparing the en bloc kidney transplantation from pediatric donor to adult recipients with other transplanted groups, the authors observe similar results between this kind of transplantation and the "optimal" donor group or living kidney donor group, regarding renal function and graft survival, and better results than the transplanted kidneys with expanded criteria donors group.

CONCLUSIONS

The results published in the current series lead us to consider this kind of transplant as an option to increase the number of transplants performed.

Intermediate-term outcome of single kidney grafts from pediatric donors weighing 10-14 kg in adult recipients

BACKGROUND

Kidneys from pediatric donors weighing <10 kg are preferably transplanted en bloc, while kidneys from donors weighing >15 kg can be safely transplanted as single kidneys. However, single kidney transplantation from donors weighing 10-14 kg is controversial and has not been well investigated.

METHODS

We analyzed the outcome of 15 recipients of single kidneys from donors weighing 10-14 kg (study group) with 40 recipients receiving an allograft from ideal deceased donors (control group).

RESULTS

After a follow-up of three yr, death-censored graft survival was 100% in both groups. The calculated creatinine clearance was lower in the study group at six months (53 vs. 71 mL/min; p = 0.01) and similar at 12 months (68 vs. 68 mL/min; p = 0.48), 24 months (81 vs. 70 mL/min; p = 0.58), and 36 months (74 vs. 69 mL/min; p = 0.59). Urinary albumin/creatinine ratios were comparable between the two groups up to two yr. At three yr, urinary albumin/creatinine ratios were higher in the study group than the control group (10.5 vs. 0.9 mg/mmol; p = 0.007). Surveillance biopsies at three and six months post-transplant revealed no evidence for focal segmental glomerulosclerosis in the study group.

CONCLUSIONS

Transplantation of single pediatric kidneys from donors weighing 10-14 kg into adult recipients provides excellent intermediate-term outcomes. Low-grade albuminuria, three yr post-transplant, might indicate late-onset hyperfiltration injury.

En bloc kidney transplantation from pediatric donors: comparable outcomes with living donor kidney transplantation

BACKGROUND

En bloc kidneys from pediatric donors have been considered suboptimal for transplantation to adult recipients and their outcomes have rarely been compared with living donor kidney transplantation (LDKT). Traditionally, there has been hesitancy in transplanting en bloc kidneys from donors weighing less than 10 kg due to high risk of technical complications.

METHODS

Retrospective chart reviews were performed to compare outcomes after pediatric en bloc (n=20, mean donor weight 11.4 kg), standard criteria deceased (n=249), and living donor (n=215) kidney transplantation in adult recipients at our center. The outcomes after en bloc transplantation from young donors weighing less than or equal to 10 kg were compared with those from 11 to 15 kg donors.

RESULTS

The 5-year graft survival after en bloc, standard deceased, and LDKT were 92%, 70%, and 88%, respectively (P=ns). There were no vascular complications, and urine leak was seen in 1 of 20 en bloc transplants. The 1-year serum creatinine of 1.1±0.2 mg/dL in recipients from less than or equal to 10 kg donors was comparable with 0.9±0.5 mg/dL in 11 to 15 kg group (P=ns).

CONCLUSIONS

Excellent long-term outcome after pediatric en bloc kidney transplantation from donors weighing less than or equal to 15 kg are comparable with those after LDKT. By using meticulous surgical technique and judicious recipient selection criteria, technical graft losses can be minimized when using en bloc pediatric kidneys from donors weighing less than or equal to 10 kg. Use of pediatric en bloc kidneys should be encouraged continuously to address the problem of organ shortage.

Utilization of small pediatric donor kidneys: a decision analysis

BACKGROUND

Given the disparity between static supply and increasing demand for organs, the greatest challenge is broadening access to the benefits of kidney transplantation. Organs from small deceased pediatric donors are a potentially underused resource. These may be transplanted as en bloc kidney transplants (EBKTs) to one recipient or as single kidney transplants (SKTs) to two recipients, albeit with an increased risk of graft failure.

METHODS

A systematic literature search identified data on transplant outcomes for recipients of organs from small pediatric deceased donors. A decision analysis model was constructed to allow the outcome in life years (LY) to be predicted for patients with end-stage kidney disease on the transplant waiting list depending on whether they received EBKT or SKT.

RESULTS

At all recipient ages, the projected LY of both recipients of an SKT was greater than the projected LY of an EBKT recipient. The net estimated gain in LY associated with the SKT technique was greatest for recipients aged 20 to 39 years (14.3 years) and lowest for recipients aged 60 to 74 years (3.36 years). Only for recipients of organs from donors weighing less than 10 kg, there was an estimated net loss of LY associated with the SKT technique across all recipient age groups.

CONCLUSIONS

There is a greater gain in overall life expectancy using SKTs, because this technique yields two recipients per donor, which more than compensates for the increased risk of graft failure.