Long-term Outcomes of Pediatric En Bloc Compared to Living Donor Kidney Transplantation: A Single-Center Experience With 25 Years Follow-Up

Graft Survival of En Bloc Deceased Donor Kidneys Transplants Compared With Single Kidney Transplants

BACKGROUND

The US Kidney Allocation System allocates en bloc deceased donor kidney grafts from donors <18 kg in sequence A along with single kidney transplants (SKTs) from kidney donor profile index (KDPI) top 20% donors. Although en bloc grafts outperform SKT grafts holding donor weight constant, it is unclear if en bloc grafts from the smallest pediatric donors perform the same as top 20% KDPI SKTs.

METHODS

Using the Scientific Registry of Transplant Recipients, we compared the donor characteristics and graft survival of en bloc grafts from the smallest donors (<8 kg) and from larger donors (≥8 kg) with SKTs by KDPI sequence for transplants performed in 2021.

RESULTS

Larger donor en blocs had similar 1-y survival to sequence A SKTs estimated by the Kaplan-Meier method (96% versus 96%, P = 0.9), but the smallest donor en blocs had significantly shorter 1-y survival than those SKTs (80% versus 96%, P < 0.01). Using transplants from 2010 to 2012, the smallest donor en blocs had similar 10-y survival to sequence A SKTs (69% versus 64%, P  = 0.3).

CONCLUSIONS

These findings suggest that future updates of the Kidney Allocation System should include a score specific to pediatric donors to account for these differences in en bloc graft survival.

Combined Urinary Reconstruction During en Bloc Kidney Transplantation From a Pediatric Donor to an Adult Recipient: A Case Report

Urinary reconstruction during en bloc kidney transplantation is challenging, with different techniques described. Here, we report a case of combined urinary reconstruction using modified Lich ureteroneocystostomy and ureteroureterostomy.

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.

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.

Dual Kidney Transplantation: Single-Center Experience

BACKGROUND

Dual and en bloc kidney transplantation are strategies used to mitigate the disparity between a reduced organ pool and an ever-increasing need for organ procurement. En bloc refers to the implantation of 2 kidneys from a pediatric donor, compensating for small renal mass, whereas dual expanded criteria donor (DECD) transplantation refers to older donors with grafts otherwise rejected for single transplant, including expanded. This study describes one center's experience with dual and en bloc transplantation.

METHODS

A retrospective cohort study of dual kidney transplants (en bloc and DECD) from 1990 through 2021. The analysis included demographic, clinical, and survival analysis.

RESULTS

Of 46 patients who underwent dual kidney transplantation, 17 (37 %) received en-bloc transplantation. The overall mean recipient age was 49.4 ± 13.9 years old, younger in the en-bloc subgroup (39.2 vs 59.8 years old, P < .01). The mean time on dialysis was 37 ± 25 months. Delayed graft function was present in 17.4 % and primary nonfunction in 6.4 %, all from the DECD group. The estimated glomerular filtration rates at 1 and 5 years were 76.7 ± 28.7 and 80.4 ± 24.8 mL/min/1.73 m2, lower in the DECD group (65.9 vs 88.7 mL/min/1.73 m2, P = 0.02). Eleven recipients lost their graft during the study period: 63.6% from death with a functioning graft, 27.3% due to chronic graft dysfunction (a mean of 76.3 months after transplantation), and 9.1% due to vascular complications. Subgroup comparison found no differences regarding cold ischemia time or length of hospitalization. Kaplan-Meier estimates, censored for death with a functioning graft, resulted in a mean graft survival of 21.3 ± 1.3 years, with survival rates of 93.5, 90.5, and 84.1% at 1, 5, and 10 years, respectively, without significant differences between subgroups.

CONCLUSIONS

Both DECD and en bloc strategies provide safe and effective options to further expand the use of otherwise rejected kidneys. Neither of the 2 techniques was superior to the other.

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

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

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.

Case Report: Mini-endoscopic combined intrarenal surgery in an en-bloc kidney transplant

Background

Overall incidence of stones in kidney transplant recipients is 1%. En-bloc kidney transplant is a rare anatomical condition in which kidney stones treatment can be extremely difficult to treat. As far as we know, no cases of staghorn calculi in en-bloc kidney transplant have been published so far.

Case presentation

A 27-year-old woman presented to the Emergency Department because of asthenia, adynamia and weight loss associated with lower urinary tract symptoms and subfebrile temperature. Ten years before, she had undergone an en-bloc kidney transplant because of end-stage renal disease secondary to perinatal asphyxia syndrome. One kidney was implanted capo-volta in the right iliac fossa and the other one in the right flank. NCCT scan showed incomplete staghorn calculi in the iliac fossa transplanted kidney. Besides, severe dilation of the native and the right flank transplanted kidney, due to two ureteral stones of 6 and 7 mm impacted in the uretero-ureteral anastomosis, was found. After hospital admission and under ceftriaxone prophylaxis, an attempt to perform primary RIRS following our COVID protocol was carried out. Nevertheless, we ended up placing a JJ stent because once the guidewire passed through the ureteral stones, purulent material came out from the ureteral orifice. She stayed 9 days in-hospital for management of postobstructive polyuria and was discharged with oral antibiotics. Three weeks afterward, we removed the stent and performed flexible ureteroscopy and holmium laser lithotripsy of the ureteral stones. In the same procedure, we performed Mini-ECIRS (21 French) previous ultrasound-guided upper pole puncture. Postoperative NCCT scan showed neither residual fragments nor operative complications.

Conclusion

This is the first clinical case reporting Mini-ECIRS in a patient with an en-bloc kidney transplant. This endourological approach seems to be a feasible, safe and effective approach to treat stones in this anatomically challenging condition.

Outcomes of small pediatric donor kidney transplants according to donor weight

A small pediatric deceased donor (SPD) weight cutoff whether to transplant as en bloc (EB) or single pediatric (SP) kidney is uncertain. Using UNOS/OPTN data (2000-2019), 27 875 SPDs were divided by (i) EB (11.4%) or SP (88.6%) and (ii) donor weight [≤10 (5.4%), >10-15 (8.3%), >15-18 (3.7%), >18-20 (2.9%), and >20 kg (79.7%)]. SP >20 kg and adult deceased donors (grouped by Kidney Donor Profile Index, KDPI, <30, 30-85, and >85) were used as references. The primary outcome was 10-year graft failure. In SP <10 kg, the hazard ratio (HR) for overall graft failure was 1.64 (1.38-2.20) compared with EB <10 kg, and 1.45 (1.18-1.80) compared with SP >20 kg. In SP >10-15 kg, HR was 1.31 (1.12-1.54) compared with EB >10-15 kg, and 1.04 (0.91-1.18) compared with SP >20 kg. In SP >15 kg, the risk was the same as SP >20 kg. Ten-year overall graft survival of SP 12 kg was comparable to SP >20 kg (62% vs. 57%). Ten-year death censored graft failure of SP >10-15 kg (70%) and SP >15-18 kg (70%) was like the adult donors with KDPI 30-85 (67%). In conclusion, we recommend single kidney transplants from SPDs with weight >12 kg to adult recipients in centers with experience in SPD transplants to optimize organ utilization.

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.

En Bloc Kidney Transplant From a Pediatric Donor to a Pediatric Recipient Through a Total Extraperitoneal Approach: A Case Report

En bloc kidney transplant remains a technically challenging procedure, especially in pediatric transplants. The intra-abdominal approach has been the preferred operation for very young children. However, the transverse incision could result in more abdominal muscle damage and intra-abdominal adhesions. If the extraperitoneal approach, which is the standard method for adult kidney transplant, could be performed in pediatric recipients, then adverse effects after a transverse incision could be avoided. A 30-month-old female recipient (13.1 kg) underwent an en bloc kidney transplant from a 36-month-old female donor (13.3 kg) who had cardiac arrest of unknown origin. The kidneys were retrieved with the en bloc technique using a bladder patch. A right Gibson incision was made along the lateral fascia of the rectus muscle of the recipient to prevent muscle fiber damage. The inferior vena cava and aorta of the donor were anastomosed to the inferior vena cava and right common iliac artery of the recipient, respectively. The bladder patch with 2 ureteral openings was directly anastomosed to the bladder of the recipient. Urination was excellent immediately after the operation. The recipient recovered quickly. The total extraperitoneal approach is feasible and has some advantages over the transverse incision, even in pediatric recipients.

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.

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.