Superiority of pediatric en bloc renal allografts over living donor kidneys: a long-term functional study

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.

Outcomes of Transplantation of Single Kidneys From Pediatric Donors Into Adult Recipients

Background Organs from extreme ages have been sought after to help increase the donor pool and alleviate transplantation wait times. There has been a growing evolution of the use of pediatric donor kidneys, including the use of en bloc kidneys (EBK), to now separating them into single kidneys (SKT), allowing for transplantation of two recipients. This study reports our outcomes utilizing SKT. Methods A retrospective review of all SKT performed from 2014 to 2022 at our center was conducted. Donors >8 years of age or >25 kg in weight were excluded. Donor and recipient characteristics and outcomes were analyzed, comparing <18 kg and ≥18 kg donor cohorts. Results Between 2014 and 2022, 81 adults received SKT. Recipients' mean age, weight, and body mass index were 49 years (22-74), 74 kg (39-136), and 26.4 mg/m2 (19.6- 39.8), respectively. Donors' mean age, weight, and kidney size were 35.7 months (8-96), 17.8 kg (8-25), and 7.2 cm (4.5-8.5), respectively. At one year post-transplant, patient survival was 100%, graft survival was 98.7%, mean serum creatinine was 1.25 mg/dL, and mean glomerular filtration rate (GFR) was 68.3 ml/min. Hyperfiltration injury was seen in 43.75% of recipients. None of the outcomes correlated with any of the donor or recipient characteristics. Conclusion Our study shows excellent short-term outcomes of single pediatric kidney transplantation in adult recipients. Exploring a lower donor weight cut-off for SKT, compared to the current Organ Procurement and Transplantation Network's (OPTN's) ≥18 kg, could expand the organ pool and lead to an increased number of transplants.

Use of Kidneys from Anencephalic Donors to Offset Organ Shortage

Background: It is well recognized that patient survival and quality of life are superior with renal transplantation than with dialysis. Organ availability is far outweighed by the large number of wait-listed patients. Additional stratagems are sought to expand the donor pool, and kidneys from anencephalic infants can be considered a source of organs, until now unexplored. We plan to assess the feasibility of using the kidneys from anencephalic infants for transplantation. Material and Methods: Information about anencephaly, the characteristics of the infant kidneys, the ethical, social and medico-legal aspects raised by the use of these kidneys, their procurement and their transplantation are reviewed. Conclusions: En bloc kidney transplants from infants can provide long-term normal renal function after an accelerated catch up growth. They are not subjected to hyperfiltration since they have a full complement of nephrons. They can be transplanted using the techniques currently available.

A 20-year experience in cadaveric pediatric en bloc kidney transplantation in adult recipients

BACKGROUND AND OBJECTIVES

En bloc kidney transplantation (EBKT) from pediatric donors into adult recipients increases the donor pool. However, this surgical procedure is not widely performed in many transplant centers. To evaluate the long-term outcomes of EBKT from pediatric donors into adult recipients in a single center.

MATERIAL AND METHODS

Retrospective analysis of 42 patients who received pediatric cadaveric EBKT in our center since 1999. Median follow-up period was 73 months (5-233) in which renal function tests were taken and complications registered.

RESULTS

We have performed 42 EBKT from pediatric donors into adult recipients in our center. The recipients' age was 44.1 ± 11.8 years. Pediatric donors were 22.4 ± 14.7 months old and weighted 11.3 ± 3.6 kg. Cold ischemia time was 15.7 ± 4.5 h. During a median follow-up of 73 months, 35 patients (83.3%) had graft survival with excellent function (first-year serum creatinine levels of 0.99 ± 0.25 mg/dl). There were seven graft losses (16.7%) in the immediate postoperative period (four cases of vascular thrombosis, one anastomosis dehiscence and two cortical necrosis).

CONCLUSIONS

The pediatric en bloc renal graft transplantation into adults is a safe technique with excellent medium- to long-term functional performance. The vast majority of significant complications leading to graft loss were reported in the immediate postoperative period. A good selection of donors and recipients as well as an adequate surgical technique are essential to minimize the occurrence of adverse events.

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.

Successful single kidney transplantation from pediatric donors less than or equal to 10 kg to adult recipient: a retrospective cohort study

BACKGROUND

Kidneys from very small pediatric donors (≤10 kg) are underutilized. Compared to en bloc kidney transplantation (EBKT), single kidney transplantation (SKT) can maximize donor resources. However, it remains unknown whether it's appropriate to perform SKTs from donors weighing ≤10 kg.

METHODS

A total of 35 adult recipients undergoing kidney transplantation from donors weighing ≤10 kg at our center from December 2014 to December 2019 were included and grouped into SKT group (n=20) and EBKT group (n=15). Transplant outcomes were retrospectively analyzed and compared between 2 groups.

RESULTS

The 1-year and 3-year death-censored graft survival in SKT group was 95%, it is not significantly higher than that in EBKT group (80%, log-rank test, P=0.38). Significant improvement in estimated glomerular filtration rate (eGFR) was noted in both groups, despite eGFR at 1 year was lower in the SKT group (P<0.01). Proteinuria was common in both groups but subsided gradually during the follow-up time. Complication rates were similar between 2 groups with no vascular thrombosis in the SKT group.

CONCLUSIONS

In conclusion, SKTs from donors weighing ≤10 kg to adult recipients achieves comparable outcomes with EBKTs, which provides evidence to support performing SKTs from donors weighing ≤10 kg in certain donor and recipient scenarios.

Survival Benefit of En Bloc Transplantation of Small Pediatric Kidneys in Children

BACKGROUND

En bloc transplantation of small pediatric kidneys in children may help expand the existing deceased donor pool; however, studies examining the long-term outcomes of en bloc transplantation in children are few.

METHODS

We used the Scientific Registry of Transplant Recipients to identify 149 pediatric en bloc recipients transplanted from October 1, 1987 to December 31, 2017. We used propensity scores to match 148 en bloc with 581 non-en bloc deceased donor recipients (matching variables: transplant age, gender, race, pretransplant dialysis, transplant center, and year). We evaluated patient and graft survival using Kaplan-Meier and Fleming-Harrington weighted log-rank test and examined survival benefit of en bloc transplantation versus remaining on the waiting list using the sequential Cox approach. We divided the study period into three 10-y intervals to assess the effect of era on outcomes.

RESULTS

Compared with non-en bloc recipients, en bloc recipients had lower 1-y graft survival (78.9% versus 88.9%; P = 0.007); however, when stratified by transplant era, lower 1-y survival was only observed in the oldest era (1987-1997). En bloc recipients had superior 10-y patient (89.0% versus 80.4%; P = 0.04) and graft survival (51.6% versus 39.9%; P = 0.04) compared with non-en bloc recipients. After multivariate adjustment, en bloc transplantation was associated with superior patient survival compared with remaining on the waiting list (adjusted hazard ratio: 0.58; 95% confidence interval: 0.36-0.95; P = 0.03).

CONCLUSIONS

En bloc transplantation of small pediatric kidneys in children is associated with superior long-term patient and graft survival. The increased risk of 1-y graft loss among en bloc recipients only appeared in the oldest era.

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.

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.

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.

Successful Single-kidney Transplantation in Adult Recipients Using Pediatric Donors Aged 8 to 36 Months: Comparable Outcomes With Those Using Pediatric Donors Aged >3 Years

BACKGROUND

Using pediatric donors for single-kidney transplantation (SKT) can increase the number of possible recipients. However, it is unclear when SKT involving small pediatric donors and adult recipients can safely be performed without compromising graft outcome.

METHODS

From 2013 to 2017, a total of 102 SKTs in adult recipients were performed in our center using pediatric donors aged <12 years. We compared the outcomes from donors aged 8 to 36 months (the small-kidney group [SKG], n = 46) and from donors aged 3 to 12 years (the big-kidney group [BKG], n = 56). The median follow-up time was 30 months in the SKG and 28 months in the BKG.

RESULTS

All patients achieved satisfactory renal function after transplantation, despite the fact that some patients (SKG, 19.6%; BKG, 28.6%) developed delayed graft function. One-year graft survival and death-censored graft survival in the SKG were 89.1% and 100%, respectively, comparable to the results in the BKG (92.9% and 98.2%). One year later, the graft and patient survival rates in both groups remained unchanged. Pulmonary infection was the main cause of death in patients with a functioning graft (SKG, 4 patients; BKG, 2 patients). Proteinuria occurred early in some patients (SKG, 30.4%; BKG, 19.6%) and decreased gradually within the first year posttransplantation.

CONCLUSIONS

SKT from pediatric donors aged 8 to 36 months to selected adult recipients produced excellent intermediate-term outcomes, comparable with those when older pediatric donors were used. This study provides evidence to support a lower age limit for SKT from pediatric donors.

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.

A Multicenter Clinical Study of Single-Kidney Transplantation vs En Bloc Transplantation with Kidneys from Deceased Pediatric Donors

BACKGROUND

There are still disputes regarding the choice of surgical approach to harvest organs from pediatric donors for organ recipients. The primary goal of this multicenter, retrospective analysis was to compare outcomes between single-kidney transplantation (SKT) and en bloc kidney transplantation (EBKT).

METHODS

Data from donors and recipients aged 4 to 18 months from 3 transplant centers over 5 year were collected to compare postoperative complications and recoveries of renal function between SKT and EBKT and to determine whether there is a difference in the 1-year patient and kidney survival rate between the 2 groups.

RESULTS

Between the SKT and EBKT groups, the incidence of delayed graft function was significantly higher in the SKT group than in the EBKT group (44.1% vs 17.3%, P = .03), and there were no significant differences in other complications (47.0% vs 59.0%, P = .36). Moreover, no significant differences were observed for the overall patient survival rate (P = .08) or the overall graft survival rate (P = .71).

CONCLUSIONS

The short-term effects of SKT make it worthy of consideration. For infants aged 4 to 18 months, SKT can provide good results, alleviating the current tense situation in kidney donation.

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.

Successful Pediatric Kidney Transplantation Into an Adult Recipient: A Case Report

BACKGROUND

The constant shortage of kidney donors prompts exploration into new strategies of transplantation. One of these strategies is the use of pediatric donors aged up to 5 years whose kidneys can be transplanted into adult recipients, mainly en bloc. This involves retrieving kidneys en bloc with aorta and inferior vena cava and anastomosing them to the recipient's external iliac vessels.

CASE PRESENTATION

In our hospital, kidneys from a 3-year-old child were transplanted to a 30-year-old man. The recipient with end-stage renal failure, due to glomerular nephritis, was dialyzed for 12 years and had 1 failed transplantation with consequent graftectomy. In 2009, kidneys were transplanted to the external iliac artery and vein with reconstruction of the renal vessels. Shortly after transplantation the patient had normal renal measures. Three months later a critical stenosis of 1 renal artery was detected. Angioplasty was performed but technical reasons did not allow for effective dilatation of the vessel. Further, 6 months after kidney transplantation (KTx) nephrotic proteinuria appeared and features of membranous nephropathy were detected in a renal biopsy. The proteinuria subsided after administration of ramipril and losartan. Doppler ultrasound revealed that 1 artery remained 90% stenotic with a peak systolic velocity of 377 cm/sec. Despite reported complications, renal function appeared normal over 7 years of observation.

CONCLUSIONS

A transplantation of 2 pediatric kidneys into an adult recipient has very high efficacy. The survival of both graft and recipient is similar to the results obtained after living donor kidney transplantation.

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 Transplantation of Pediatric Kidneys Despite Vascular Injuries

The gap between the kidney transplant recipient list and the number of organs available for transplantation continues to grow. Pediatric donors help fill a small and valuable portion of that gap. Normally these organs are transplanted en-bloc by closing the proximal vascular caps and using the distal aorta and distal inferior vena cava (IVC) for inflow. They are however commonly injured during the donor operation making the standard operation for pediatric en-bloc transplantation not possible. This case report presents two cases in which injured small pediatric kidneys were transplanted successfully in adult patients. We are presenting two examples of common vascular injuries to small pediatric kidneys, one venous and one arterial. In both scenarios, the kidneys were transplanted using a modification to the standard technique. The two kidneys were separated and the technique of implantation was modified to allow safe transplantation. This way we were able to transplant both kidneys successfully and using a reproducible methodology. Both recipients were young adults. There were no surgical complications.

Bilateral adrenal hemorrhage in a neonatal kidney donor

EKT from neonatal donors remains rare despite successful outcome being reported. The surgical aspects of neonatal abdominal organ recovery remain unfamiliar to the vast majority of abdominal organ recovery teams and renal transplant surgeons. BAH is not uncommon in newborn babies suffering distress in the perinatal period. BAH is often also associated with RVT and will impact on utilization of kidneys for transplantation. We present a case of a neonatal kidney donor with massive BAHs discovered at the time of organ recovery. This made the procurement challenging. Both kidneys were recovered en bloc with pancreas and the liver with aorta and inferior vena cave as vascular conduits. The kidneys were successfully implanted into an adult recipient with good function at 1-year follow-up. Association between adrenal hemorrhage and RVT needs to be considered before utilizing such kidneys. This case exemplifies successful outcome after careful assessment and transplantation of such kidneys.

Expanding the Envelope: Favorable Outcomes Utilizing Kidneys From Small Pediatric Donors (≤ 15 kg)

BACKGROUND

Utilization of kidneys from small pediatric donors (SPDs ≤ 15 kg) is limited. Decisions to split and use the kidneys for 2 recipients remain controversial.

METHODS

Retrospective single-center study aimed primarily at evaluating graft loss within 30 days after transplant using SPD kidneys. Recipients were divided into group A (donor weight < 10 kg, n = 24) and group B (≥ 10  kg, n = 16).

RESULTS

Forty transplants were performed with 100% patient survival. Mean follow-up was 402 days, overall graft survival was 95%, with 91.7% and 100% in groups A and B, respectively (P = .24). Mean recipient-to-donor weight ratio (RTDWR) was higher in group A (10.5 vs 6.3, P < .001). Surgical complications were similar between the groups. These were more common with en bloc compared to single implantation (P = .05), and RTDWR was the main predictor (P = .005). Graft function was similar between the groups; mean 12-month creatinine was 1.2 mg % and eGFR was 58.2 mL/min/1.73 m². Sixteen out of 38 patients developed proteinuria (42%) with no difference among subgroups, although male recipients were at a higher risk (OR = 8.4 [95% CI 1.5-46.1], P = .014); 83% responded to therapy.

CONCLUSION

Utilization and early splitting of SPD kidneys yields favorable graft survival and function irrespective of donor weight and age. Early splitting should be considered.

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.

Very small pediatric donor kidney transplantation in pediatric recipients

Kidneys from very small pediatric donors (age <5 years, weight <21 kg) may be a means to increase the donor pool for pediatric recipients. Transplantation of small pediatric kidneys is more commonly performed in adult recipients due to the increased risks of technical complications, thrombosis, and early graft failure. While these risks are abrogated in adult recipients by limiting the donor weight to ≥10 kg and using the EB technique, it is unknown whether pediatric recipients achieve comparable results. US national data were assessed for all first-time, deceased-donor, kidney-only pediatric recipients, 1/1996-10/2013, who received very small pediatric donor grafts or grafts from ideal adult donors. We identified 57 pediatric EB, 110 pediatric SK, and 2350 adult transplants. The primary outcome was 3-year all-cause graft survival. Kaplan-Meier curves showed worse outcomes for pediatric grafts compared to adult ideal grafts (P=.042). On multivariate analysis, pediatric recipients of SK grafts had significantly higher HRs (aHR 2.01, 95% CI 1.34-3.00) and pediatric recipients of EB grafts had somewhat higher non-significant HRs (1.57; 95% CI 0.88-2.79) for graft survival. These results suggest cautionary use of very small pediatric donors as a source to expand the donor pool for pediatric candidates.

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 kidney transplantation from infant donors younger than 10 months into pediatric recipients

Early graft loss and poor graft function limit the use of kidneys from infant donors. Six en bloc kidney transplantations were performed from infant donors younger than 10 months into pediatric recipients between November 2012 and September 2015 at our center. We retrospectively analyzed recipient and donor demographics, surgery procedures, complications, graft function and size, and patient and graft survival with a follow-up of 6-39 months (median 15.5 months). Donor age ranged from 1 to 10 months with weight ranging from 3.5 to 10 kg. Recipient age ranged from 10 to 16 years with weight ranging from 30 to 39 kg. One kidney was removed due to arterial thrombosis during surgery, while the other kidney of this en bloc graft remained viable. Urine leak followed by bilateral ureteral obstruction occurred in one recipient. All of the recipients showed immediate graft function. The size of the en bloc kidney increased from 4.2±0.6 cm to 7.6±0.6 cm 6 months after surgery. Patient and graft survival were both 100% at the last follow-up. Our results show that en bloc kidney transplantation from infant donors younger than 10 months into pediatric recipients is effective under the condition of experienced surgical techniques and perioperative management.

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.

Renal Transplantation From Pediatric Donors in the United Kingdom

BACKGROUND

Significant disparity exists in the United Kingdom between the need for organ transplant and supply of deceased donor organs. In the recent years, efforts to increase donation has improved the rate of mainly deceased donors after circulatory death and from older donors. The rate of donation from pediatric population has remained low and those younger than 2 years including neonatal donation has remained largely unexplored.

METHODS

A retrospective review of the outcome of renal transplantation from pediatric donor (<18 years) kidneys in the United Kingdom.

RESULTS

Our results show a poor referral and conversion rate, and high discard rate (43%) of kidneys procured from donors younger than 2 years. During the 15-year study period (1997-2011), 47 donors younger than 2 years were referred (3 per year). Of these, 26 proceeded to donation resulting in 17 transplants (65% utilization). The referral rate for donors 2 years or older to younger than 5 years also remains low (76 in 15 years), but the conversion (88%) and utilization rates (73%) are better in this group. There was better utilization in donors aged 5 years or older to younger than 18 years. Overall graft and patient survival remains excellent in all 3 groups; with comparable survival of 82%, 85%, and 77% (P = 0.29) with mean follow-up periods of 9, 12.5, and 11.8 years, respectively.

CONCLUSIONS

Despite excellent outcome, the referral, donation, and utilization of kidneys from donors younger than 5 years and particularly those younger than 2 years remain low. We suggest implementing improved strategies to increase donation from this group of population.

Graft arterial stenosis in kidney en bloc grafts from very small pediatric donors: incidence, timing, and role of ultrasound in screening

In previous studies with different donor selection criteria and noncontemporary surgical techniques, graft arterial stenosis (GAS) has been reported to occur more frequently in adult recipients of pediatric en bloc renal allografts (EBKT) as compared to single adult donor allografts. The purpose of our study was to evaluate the incidence of GAS within our EBKT recipient population and to evaluate clinical and imaging features of those cases with GAS. In a retrospective cohort study, we analyzed 182 EBKT performed at a single institution. We identified cases of suspected GAS based on clinical factors, lab results, and noninvasive imaging. Diagnosis of GAS was confirmed by digital subtraction angiography. Two EBKT recipients (1.1% of 182) had angiographically confirmed GAS at 2.5 and 4.5 months after transplant. In both cases, the stenoses were short segment within the proximal (perianastomotic) donor aorta, color Doppler ultrasound demonstrated peak systolic velocities of >400 cm/s, and poststenotic parvus tardus waveforms were present. Both patients underwent angioplasty and demonstrated postintervention improvement in renal function and blood pressure. Restenosis did not occur during follow up. In conclusion, recipients of EBKT have a low incidence of GAS, similar to the lowest reported for adult single allografts.

Recent developments in kidney transplantation in children

PURPOSE OF REVIEW

Renal transplantation in childhood is a well established procedure with excellent short-term outcomes. However, waiting times for transplantation are still relatively long if living donation cannot be performed, and long-term outcomes after transplantation have not significantly improved during the last decade.

RECENT FINDINGS

This review describes alternative modalities to improve donation rates such as en bloc kidney transplantation from young donors, ABO-incompatible transplantation and kidney paired donation. This review also deals with long-term post-transplant morbidities, such as follows: first, medication side-effects (metabolic syndrome, cardiovascular disease) and with the benefits of steroid and calcineurin inhibitor drug minimization; second, the deleterious impact of viral infections and their management and third, chronic antibody-mediated rejection, its therapeutic and prevention possibilities.

SUMMARY

Donor shortage and long-term morbidities, after transplantation, are still relevant issues in paediatric renal transplantation medicine. Significant research and efforts have been made to advance the field and create novel approaches for improvement of transplantation rates and post-transplant graft or patient survival. These modalities are to be established in the routine setting.

Optimizing recovery, utilization and transplantation outcomes for kidneys from small, ≤20 kg, pediatric donors

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

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.

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.

Early inhibition of the renin-angiotensin system improves the long-term graft survival of single pediatric donor kidneys transplanted in adult recipients

Transplanting single pediatric donor kidneys into adult recipients has an increased risk of hyperfiltration injury and graft loss. It is unknown if renin-angiotensin system (RAS) blockers are beneficial in this setting. We retrospectively analyzed 94 adults who received single kidneys from donors <10 years old during 1996-2009. The recipients were divided into group 1 with RAS blockers (n = 40) and group 2 without RAS blockers (n = 54) in the first year of transplant. There was no significant difference in any donor/recipient demographic between the two groups. Graft function, incidence of delayed graft function, acute rejection, and persistent proteinuria were not statistically different either. Kaplan-Meier estimated death-censored graft survivals were significantly better in group 1 than in group 2: 95 vs. 81.2%, 82.4 vs. 61.2%, 72.6 vs. 58.5%, and 68.5 vs. 47.2% at 1, 3, 5, and 7 years, respectively (log rank P = 0.043). Multivariable analysis found persistent proteinuria was a risk factor for graft loss (OR 2.70, 95% CI 1.33-5.49, P = 0.006), while RAS blockers reduced the risk of graft loss (OR 0.38, 95% CI 0.18-0.79, P = 0.009). Early RAS blockade therapy in the first year of transplant is associated with superior long-term graft survival among adults transplanted with single pediatric donor kidneys.

Outcomes of children receiving en bloc renal transplants from small pediatric donors

The utilization of en bloc renal allografts from small pediatric donors has been adopted as an effective strategy to expand the organ donor pool in adult recipients. Data in children are limited. The aim of our study is to describe the outcomes of en bloc renal transplants in children from our center. Medical records of children receiving pediatric en bloc renal transplants at our institution from January 2007 were abstracted. Data collected included recipient and donor demographics, operative technique and complications, and post-operative studies. Eight children received en bloc renal transplants at a median age of 17 yr; median follow-up was 0.9 yr. Donor body weight ranged from 4 to 22 kg. One kidney was lost to intra-operative thrombosis, while the other kidney from this en bloc graft remained viable. All grafts showed increased renal size at follow-up ultrasound. Surveillance biopsies showed glomerulomegaly in two patients. At last follow-up, the median eGFR was 130 mL/min/1.73 m(2). The urinary protein to creatinine ratio was normal in four of seven patients. Our data suggest that in experienced centers, en bloc renal transplantation from young donors into pediatric recipients is effective. Long-term follow-up to monitor for complications, including hyperfiltration injury, is warranted.

Pediatric en bloc kidney transplantation into pediatric recipients: the French experience

Chronic shortage of available donor organs has led to re-evaluation of the use of en bloc kidney transplants. Although excellent results have been reported in adult patients, experience in pediatric patients remains limited because of potential early complications and poor long-term graft outcome. We report 14 pediatric en bloc renal transplantations into 14 pediatric recipients, performed between 1990 and 2007 in France. We retrospectively analyzed demographic data, postoperative complications, and graft function with a median follow-up of five yr. Donor age ranged from four to 54 months. Complications were vascular graft thrombosis in four patients, leading to graft loss in two cases, and to excellent long-term graft function in the two others. Two hemorrhagic complications resulted in death in one case and in graft loss in the other. Six acute rejection episodes occurred in four patients. Median glomerular filtration rate at three months, one, five, and 10 yr was 90.8, 106, 87.8, and 66.1 mL/1.73 m(2) /min. We believe that en bloc transplantation may be an option for children with end-stage kidney disease.

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.

When is it reasonable to split pediatric en bloc kidneys for transplantation into two adults?

BACKGROUND

Traditionally, kidneys from donors ≥60 years old and pediatric kidneys are considered marginal organs for transplantation. Pediatric donor kidneys are underutilized for transplantation into adult recipients due to concern for poor outcomes.

METHODS

Using data from the Organ Procurement and Transplant Network, we analyzed patterns of pediatric kidney use (single vs en bloc) in the United States from 1987 to 2007. Using the Cox proportional hazards model, graft outcomes of pediatric donor kidneys transplanted as single vs en bloc grafts from different donor weight groups were compared with renal transplantation from donors ≥60 years old in an attempt to define a pediatric donor weight at which kidneys can be justifiably split to expand the donor pool.

RESULTS

Compared with older donor kidneys, graft failure risk of pediatric single kidneys was consistently lower when the donor weight exceeded 10 kg. On the other hand, graft survival benefit for pediatric en bloc kidneys was evident starting at donor weight ≤10 kg in comparison to older donor kidneys. Pediatric en bloc kidneys performed consistently better than pediatric single kidneys for all donor weight groups.

CONCLUSIONS

Splitting of pediatric donor en bloc kidneys for transplantation into 2 adults when the donor weight exceeds 10 kg was associated with acceptable graft outcomes. This practice, along with increased use of small pediatric donor kidneys, may help to alleviate the waiting list burden in renal transplantation.