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

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.

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.

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.

Single kidney transplantation from pediatric deceased donors in China: the outcomes and risk factors of graft survival

BACKGROUND

Pediatric deceased donors offer great potential for expanding the organ donor pool. The utilization of pediatric donor kidneys has been explored by numerous transplant centers; however, the transplant outcome and risk factors have not been well elucidated. The aim of this study was to demonstrate the safety and risk factors of transplant outcome from pediatric deceased donors.

METHODS

We retrospectively analyzed 484 cases of single kidney transplantation (SKT) with pediatric donor kidneys performed at our center from January 2012 to March 2021. The recipients were grouped by age: child (≤12 years; n=143), adolescents (12-18 years; n=86), and adults (≥18 years; n=255). The overall prognosis of the recipients was analyzed, and the post-transplant outcomes were compared among the three groups and assessed by univariate and multivariate analyses using the Cox proportional risk model.

RESULTS

The median follow-up time was 26.7 months. The 1- and 3-year patient survival rates were 98.7% and 96.8%, respectively. The 1- and 3-year death-censored graft survival (DCGS) was 96.1% and 92.7%, respectively. The overall estimated glomerular filtration rates (eGFRs) at 1 and 3 years were 80.0±24.5 and 84.2±25.2 mL/min/1.73 m²; the 3-year eGFR of the three groups were comparable and all were over 80 mL/min/1.73 m². Rejection was an independent risk factor for death-censored graft failure within 3 years after transplantation [hazard ratio (HR) =3.85; P=0.001], and was the primary cause of graft losses in the adolescent group. Thrombosis was more common within 1-month post-transplant in the child recipients (P<0.05), and its incidence was higher in recipients with donor body weight (DBW) ≤11 kg.

CONCLUSIONS

SKT from pediatric donors could achieve decent outcomes. Rejection was an independent risk factor of graft survival, especially for adolescent recipients. Child recipients may compromise early transplant outcomes due to vascular thrombosis, which might be related to small (DBW ≤11 kg) pediatric donors.

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

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

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.

Transplantation of 2-Month-Old En Bloc Pediatric Kidneys After a Complex Vascular Reconstruction - Traveling 2500 Miles to Get Transplanted: A Case Report

BACKGROUND En bloc pediatric kidneys (EBPK) are one potential solution to increase the number of organs available in the donor community, thus promoting transplantation of these allografts into adult recipients. However, EBPK transplantation has been traditionally considered suboptimal due to concerns for perioperative complications, mainly vascular thrombosis. We report an en bloc kidney transplantation using vascular grafts from another deceased donor to extend the EBPK aorta and vena cava and create a tension-free anastomosis with recipient external iliac vessels. CASE REPORT A pair of 2-month-old female en bloc kidneys weighting 6 kg were transplanted to a 30-year-old adult male. Prolonged cold ischemic time (CIT) was related to high refusal rate and long travel from Nevada to Miami. Prior to transplantation, the EBPK were connected to the LifePort Renal Preservation Machine® and deemed transplantable only after showing a significant improvement in perfusion parameters. Back-table reconstruction was conducted through an end-to-end anastomosis between an adult deceased donor common iliac artery and vein grafts to the inferior vena cava and aortic distal ends, respectively. The patient displayed immediate graft function (IGF) without any postoperative complications, showing a creatinine of 1.5 mg/dl at 4-month follow-up. CONCLUSIONS Use of renal preservation machine (RPM) and refined back-table reconstruction of these allografts are important tools to improve the significant discard rate and improve outcomes of EBPK.

Single versus en bloc kidney transplant from donors less than or equal to 15 kg to pediatric recipients

With small kidneys, EBKTs could provide sufficient renal mass but could lead to inefficient use of resources, while SKTs could result in insufficient function due to small renal mass. We aimed to compare the outcomes of EBKT and SKT from small donors weighing ≤15 kg to pediatric recipients. We retrospectively reviewed all pediatric patients who met the inclusion criteria between January 1, 1984, and April 30, 2019, at a single institution. Of a total of 23 patients, 12 received EBKT and 11 received SKT. The median age of donors, weight of donors, and weight of recipients were comparable between the two groups. The median age of recipients and median weight of allografts were greater in the EBKT group than in the SKT group. The median follow-up was 53.9 months. There was no significant difference in eGFR, protein creatinine ratios at 1-year follow-up, and overall graft survival. The size of the kidney increased by approximately 13%-43% in the EBKT group and 40%-60% in the SKT group. This study demonstrated that kidneys from small donors weighing 5-15 kg could be split in pediatric recipients without compromising the outcome.

Outcome of Kidney Transplantation With Transumbilical Laparoendoscopic Single-Site Donor Nephrectomy: A Single-Center Experience

AIM

The aim of this study is to present the outcome of kidney transplantation after laparoendoscopic single-site donor nephrectomy (LESS DN) compared with conventional laparoscopic donor nephrectomy (LDN) in a single-center experience.

METHODS

This retrospective study compares data from the initial experience with 110 consecutive LESS DN donors and their recipients (group A) with 205 consecutive conventional LDN donors and their recipients (group B).

RESULTS

This study compared 110 LESS DNs completed in an 18-month period with 205 LDNs completed in the immediately preceding 42-month period. All procedures were performed by the same surgeon. In groups A and B, respectively, the incidence of immediate graft function was 90% vs 91.2%, slow graft function was 9% vs 5.3%, delayed graft function was 0.9% vs 2.9%, graft loss was 0.9% vs 2.9%, and death with a functioning graft was 0.9% vs 1.5%. The mean serum creatinine levels were 1.3 ± 0.93 mg/dL vs 1.4 ± 1.2 mg/dL (P = .447), 1.1 ± 0.33 mg/dL vs 1.2 ± 0.75 mg/dL (P = .184), and 1.05 ± 0.25 mg/dL vs 1.1 ± 0.39 mg/dL (P = .224) at 7, 30, and 365 days after transplantation. The estimated glomerular filtration rate at 1 year was 88 ± 18.2 vs 83 ± 12.2 mL/min/1.73 m² (P = .004). The mean donor operative times in groups A and B were 175.9 ± 24.9 minutes vs 199.88 ± 37.06 minutes (P = .0001), respectively, and the mean warm ischemia time was 5.2 ± 1.02 minutes vs 3.64 ± 1.38 minutes, respectively (P = .0001). The mean body mass index, the incidence of complex vascular anatomy, and the rate of complications were the same in the 2 donor groups.

CONCLUSIONS

The outcome of kidney transplantation after LESS DN is comparable to conventional LDN. LESS DN can be employed as the primary approach for kidney donation with low donor risk and without compromising recipient outcomes.

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.

Dual Kidney Transplantation from Donors at the Extremes of Age

BACKGROUND

The study purpose was to analyze outcomes in recipients of pediatric dual en bloc (PEB) kidneys from small pediatric donors (SPDs, age ≤ 3 years) and dual kidney transplants (KTs) from adult marginal deceased donors (DDs) in the context of the Kidney Donor Profile Index (KDPI).

STUDY DESIGN

This was a single center retrospective review. Recipient selection included primary transplant, low BMI, low immunologic risk, and informed consent. All patients received antibody induction with FK/MPA/± prednisone.

RESULTS

From 2002 to 2015, we performed 34 PEB and 73 adult dual KTs. Mean donor ages were 17 months for the PEB and 59 years for the dual KTs; mean KDPIs were 73% for PEB and 83% for dual KT, and mean cold ischemia times were 21.0 hours for PEB and 26.5 hours for dual KT. Adult dual KT recipients were older (mean age 38 years for PEB and 60 years for dual KT) and had shorter waiting times (mean 25 months for PEB and 12 months for dual KT). With a mean follow-up of 7.6 years, actual patient survival (88% for PEB and 62% for dual KT) and graft survival (71% for PEB and 44% for dual KT) rates were higher in PEB compared with dual KT. Death-censored kidney graft survival rates were 77% for PEB and 58% for dual KT. Delayed graft function (DGF) rates were 15% for PEB and 23% for dual KT; incidences of DGF in single kidney transplantations from SPDs and adult nonmarginal DDs were 20% and 32%, respectively. Based on actual 5-year graft survival rates, the adjusted KDPIs for dual PEB and dual KTs were 3% and 60%, respectively.

CONCLUSIONS

Acceptable mid-term outcomes are associated with PEB and adult dual KTs, which may expand the donor pool and prevent kidney discard. The KDPI is inaccurate for predicting outcomes from either PEB from SPDs or dual KT from adult marginal DDs, which may prevent acceptance of these organs.

A novel technique for en bloc kidney transplantation from infant donors with extremely low body weight by using the distal abdominal aorta as an outflow tract

Pediatric kidney donors remain underutilized due to the high risk of postoperative thrombosis. To address this problem, we developed a novel en bloc kidney transplantation technique using donor thoracic aorta and the distal abdominal aorta as inflow and outflow tracts, respectively. Briefly, eight kidneys from deceased infant donors under five months old and with low body weight (1.9-4.9 kg) were transplanted en bloc into four pediatric and four adult patients. The donor's common iliac artery or external iliac artery was anastomosed to the recipient's distal external iliac artery or inferior epigastric artery, respectively, as an outflow tract. Recipients received basiliximab or antithymocyte globulin as induction therapy followed by tacrolimus, mycophenolate mofetil, and prednisone but without prophylactic anticoagulation. Delayed graft function was observed in one patient but was reversed at 90 days posttransplant. Two patients had urine leakage, which was cured by conservative treatment. Two recipients developed lung infections that eventually cleared. No patients experienced posttransplant vascular thrombosis. After 1-1.5 years of follow-up, all patients are well and have normal serum creatinine levels. In conclusion, this novel en bloc kidney transplantation technique using a modified arterial inflow and outflow tract can prevent vascular thrombosis and provide adequate graft function.

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.

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 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.