Long-term outcome of kidney transplantation in patients with congenital anomalies of the kidney and urinary tract

Vesicoureteral Reflux in Transplanted Kidney Among Children With Congenital Anomalies of Kidney and Urinary Tract: Case-Control Study Assessing Impact on Renal Function and Graft Survival

BACKGROUND

Congenital anomalies of the kidney and urinary tract (CAKUT) are a common cause of kidney failure in childhood. Renal transplantation is the modality of treatment used for kidney failure that promotes improved quality of life for pediatric patients. It is believed that patients with CAKUT are more predisposed to developing graft reflux in the post-transplant period, but its influence on graft survival is poorly understood. A comparative analysis between patients with and without VUR in the graft was made to determine the impact of reflux on graft function and survival in pediatric CAKUT patients.

METHODS

A retrospective case-control study of patients undergoing first renal transplantation between April 2008 and October 2021 was done. The study included CAKUT individuals who underwent voiding cystourethrogram after transplantation. Patients were stratified into a group without reflux in the transplanted kidney (controls) and a group with reflux (cases). Six-year graft and patient survivals were calculated and compared using Kaplan-Meier curves and the log-rank test.

RESULTS

A total of 257 CAKUT patients were studied. Of this group, 63 (24%) underwent voiding cystourethrogram after transplantation, and 48 (76%) had reflux in the transplanted kidney. Estimated six-year survival of the graft was 72% in the control group versus 96% in the case group (log-rank 0.889). The median follow-up time after transplantation in years was 7.6 in controls and 6.6 in cases (p = 0.383).

CONCLUSIONS

Pediatric patients with CAKUT who presented reflux in transplanted kidneys had similar graft and patient survivals compared to patients without reflux.

A systematic review of kidney transplantation outcomes in patients with end-stage renal disease due to childhood lower urinary tract malformations

PURPOSE

Patients with lower urinary tract malformations (LUTM) were suspended from kidney transplantation (KT) programs in the past due to various concerns. Consequently, only a limited number of studies have explored this topic at hand. In this study, our objective was to perform a systematic review (SR) to evaluate the current evidence regarding KT outcomes as well as patient survival (PS), postoperative complications and urinary tract infections (UTI) in individuals with childhood LUTM.

METHODS

The search encompassed databases of Web of Science, Medline (via PubMed), and Embase (via Scopus) to identify all studies reporting outcomes on KT for patients with LUTM. The research included articles published in English from January 1995 till September 2023.

RESULTS

Of the 2634 yielded articles, 15 met the inclusion criteria, enrolling a total of 284,866 KT patients. There was significantly better 5-year graft survival (GS) in recipients with LUTM compared to the control group (RR, 1.04; 95% CI 1.02-1.06); while GS at 1-year and 10-year, and PS at 1-year, 5-year and 10-year were similar between groups. On the other hand, the postoperative UTI rate was significantly higher in the LUTM group (RR: 4.46; 95% CI 1.89-10.51). However, data on serum creatinine and estimated glomerular filtration rate on follow-up were insufficient.

CONCLUSION

GS and PS rates appear to be similar in patients with childhood LUTM and those with normal lower urinary tract functions. Despite a higher postoperative UTI rate within this patient group, it appears that this has no effect on GS rates.

Review - Renal transplantation for congenital urological diseases

INTRODUCTION

Congenital Anomalies of the Kidney and Urinary Tract (CAKUT) are structural disorders originating prenatally and present at birth. Affecting 4.2 to 1000 per 10,000 births globally, CAKUT includes conditions like posterior urethral valves, cloacal anomalies, and reflux nephropathy. These anomalies can lead to chronic kidney disease (CKD) or end-stage kidney disease (ESKD) in children, necessitating renal replacement therapy or transplantation.

OBJECTIVES

This article aims to provide an updated perspective on pediatric kidney transplantation for children with CAKUT, emphasizing pre-transplant evaluation and management to optimize long-term outcomes.

METHODS

A comprehensive urologic evaluation is essential for children with ESKD being considered for kidney transplantation. Key pre-transplant investigations include kidney/bladder ultrasound (US), voiding cystourethrogram (VCUG), uroflowmetry, and urodynamics (UDS)/video-urodynamics (VUDS). Non-operative interventions such as pharmacotherapy and clean intermittent catheterization (CIC) are also considered. Surgical interventions, like augmentation cystoplasty or continent catheterizable channels, are evaluated based on individual patient needs.

RESULTS

Kidney/bladder US and VCUG provide essential anatomical information. UDS offers comprehensive functional data, identifying hostile bladders needing pre-transplant optimization. Non-surgical measures like anticholinergics and CIC improve bladder function, while surgical options enhance compliance and capacity. Concurrent interventions during transplantation are feasible but require careful consideration of risks and benefits.

DISCUSSION

Children with CAKUT undergoing kidney transplantation exhibit comparable or better graft survival rates than those without CAKUT. However, those with lower urinary tract obstructions (LUTO) may have poorer long-term outcomes. UDS is crucial for evaluating bladder function pre-transplant, guiding the need for interventions. Long-term monitoring for urinary tract infections (UTIs) and bladder dysfunction is essential.

CONCLUSION

Optimal outcomes in pediatric kidney transplantation for CAKUT patients require thorough pre-transplant evaluation and management, particularly for those with LUTO. Multidisciplinary approaches ensure careful monitoring and timely interventions, improving graft survival and quality of life for these patients.

[Kidney transplantation in children with complex urogenital malformations-what should be considered?]

BACKGROUND

Congenital anomalies of the kidneys and urinary tract (CAKUT) are the most common cause of end-stage renal disease (ESRD) in children. Approximately one third of children with CAKUT have lower urinary tract dysfunction (LUTD).

AIM

This article highlights the important aspects that need to be considered in kidney transplantation of children with complex urogenital malformations.

MATERIALS AND METHODS

The paper reviews the existing literature regarding the evaluation, preparation, perioperative management, and follow-up of children with complex urogenital malformations and ESRD undergoing renal transplantation.

RESULTS

Comprehensive diagnostics are required before any pediatric kidney transplantation. If LUTD is suspected, voiding cystourethrography and a urodynamic examination should be performed. Treatment of symptomatic vesicoureterorenal reflux and LUTD is mandatory prior to pediatric kidney transplantation. Following successful kidney transplantation of children with congenital urogenital malformations, lifelong follow-up is required. Regular reevaluations of the bladder by means of urodynamic examinations are necessary. In patients following bladder augmentation with intestinal segments or urinary diversions in childhood, regular endoscopic examinations of the urinary tract are recommended to rule out secondary malignancy.

CONCLUSION

Treatment of children with complex urogenital malformations should be carried out in centers with appropriate expertise.

Clean Intermittent Catheterization in Children under 12 Years Does Not Have a Negative Impact on Long-Term Graft Survival following Pediatric Kidney Transplantation

BACKGROUND

Congenital anomalies of the kidneys and urinary tract (CAKUTs) are one of the most prevalent primary causes of end-stage renal disease (ESRD) in young children, and approximately one-third of these children present with lower urinary tract dysfunction (LUTD). Many children with LUTD require therapy with clean intermittent catheterization (CIC). CIC commonly leads to bacteriuria, and considerations have arisen regarding whether CIC in immunosuppressed children is safe or whether repeated febrile urinary tract infections (UTIs) may lead to the deterioration of kidney graft function.

MATERIAL AND METHODS

We retrospectively reviewed all cases of primary kidney transplantation performed in our center between 2001 and 2020 in recipients aged less than twelve years. The number of episodes of febrile UTIs as well as the long-term kidney graft survival of children undergoing CIC were compared to those of children with urological causes of ESRD not undergoing CIC, as well as to those of children with nonurological causes of ESRD.

RESULTS

Following successful kidney transplantation in 41 children, CIC was needed in 8 of these patients. These 8 children undergoing CIC had significantly more episodes of febrile UTIs than did the 18 children with a nonurological cause of ESRD (p = 0.04) but not the 15 children with a urological cause of ESRD who did not need to undergo CIC (p = 0.19). Despite being associated with a higher rate of febrile UTIs, CIC was not identified as a risk factor for long-term kidney graft survival, and long-term graft survival did not significantly differ between the three groups at a median follow-up of 124 months.

CONCLUSIONS

Our study demonstrates that, under regular medical care, CIC following pediatric transplantation is safe and is not associated with a higher rate of long-term graft loss.

Kidney transplant access for children and young adults with congenital anomalies of the kidney and urinary tract

PURPOSE

Although congenital anomalies of the kidney and urinary tract (CAKUT) are among the leading causes of end-stage kidney disease (ESKD) in children and young adults, kidney transplantation access for this population has not been well studied in the US. We compared transplantation access in the US based on whether the etiology of kidney disease was secondary to CAKUT, and additionally by CAKUT subgroups (anatomic vs. inherited causes of CAKUT).

METHODS

Using the United States Renal Data System, we conducted a retrospective cohort study of 80,531 children and young adults who started dialysis between 1995 and 2015. We used adjusted Cox models to examine the association between etiology of kidney disease (CAKUT vs. non-CAKUT, anatomic vs. inherited) and receipt of kidney transplantation, and secondarily, receipt of a living vs. deceased donor kidney transplant.

RESULTS

Overall, we found an increased likelihood of kidney transplantation access for participants with CAKUT compared to those without CAKUT (HR 1.23; 95% CI 1.20-1.27). Among the subset of individuals with CAKUT as the attributed cause of ESKD, we found a lower likelihood of kidney transplantation in those with anatomic causes of CAKUT compared to those with inherited causes of CAKUT (adjusted HR 0.85; 0.81-0.90).

CONCLUSION

There are notable disparities in kidney transplantation rates among CAKUT subgroups. Those with anatomic causes of CAKUT started on dialysis have significantly reduced access to kidney transplantations compared to individuals with inherited causes of CAKUT who were initiated on dialysis. Further studies are needed to understand barriers to transplantation access in this population.

Bladder salvage in children with congenital lower urinary tract malformations undergoing renal transplant

INTRODUCTION

Patients with Congenital Lower Urinary Tract Malformations (CLUTM) have increased risk of post-transplant complications if bladder dysfunction is not addressed. Pretransplant assessment may be difficult if urinary diversion has been previously applied. In case of low capacity and/or low compliance and/or high-pressure overactive bladder, transplantation into a diverted or augmented system may be required. We hypothesised that a bladder optimization pathway may help identify potentially salvageable bladders and prevent unnecessary bladder diversion or augmentation. We propose a structured bladder optimisation and assessment programme for safe transplant and native bladder salvage.

MATERIAL AND METHODS

Data of 130 children who underwent renal transplant between 2007 and 2018 were retrospectively collected and analysed. All patients with CLUTM were assessed by urodynamic study. Bladder optimisation: Low compliance bladders were managed with anticholinergics and/or Botulinum toxin A (BtA) injections. Those who had urinary diversion for their pathology underwent a structured assessment and optimisation process with undiversion/anticholinergics/BtA/bladder cycling/Clean Intermittent Catheterisation (CIC)/Suprapubic catheter (SPC) as indicated. Details of medical and surgical management were collected (Figure 1).

RESULTS

Between 2007 and 2018, 130 renal transplants were done. Of these, 35 (27%) had associated CLUTM (PUV in 15, neurogenic bladder dysfunction in 16, other pathology in 4) which was managed in our centre. Ten patients needed initial diversion in the form of vesicostomy (2) or ureterostomy (8) to manage primary bladder dysfunction. The median age at transplant was 7.8 years (range 2.5-19.6). After bladder assessment and optimisation, a safe bladder was demonstrated in 5 of 10 with initial diversion leading to transplant into native bladder (without augmentation). Overall, of the 35 patients, 20 (57%) had transplant into native bladder, 11 patients had ileal conduits and 4 had bladder augmentation. Eight required help with drainage: three with CIC, four with Mitrofanoff, and one had reduction cystoplasty.

CONCLUSION

With a structured bladder optimisation and assessment programme, safe transplant and 57% native bladder salvage is achievable in children with CLUTM.

Approach to acute kidney injury following paediatric kidney transplant

PURPOSE OF REVIEW

In a child with evidence of acute kidney injury (AKI) following renal transplantation, it is important to quickly and accurately diagnose the cause to enable timely initiation of therapeutic interventions. The following article will discuss the differential diagnosis of acute graft dysfunction in paediatric kidney transplant recipients. This review will systematically guide the clinician through the common and less common causes and provide updates on current treatments.

RECENT FINDINGS

In patients with signs of graft dysfunction, rejection is an important cause to consider. Diagnosis of rejection relies on biopsy findings, an invasive and costly technique. Over the past 5 years, there has been a focus on noninvasive methods of diagnosing rejection, including serum and urinary biomarkers.

SUMMARY

This review discusses the differential diagnosis of acute graft dysfunction following transplant, with a focus on acute rejection, urinary tract infections and common viral causes, prerenal and postrenal causes, nephrotoxic medications, specifically calcineurin inhibitor toxicity, thrombotic microangiopathy and recurrence of the underlying disease. Each condition is discussed in detail, with a focus on clinical clues to the cause, incidence in the paediatric population, workup and treatment.

Outcomes of kidney transplantation in patients with congenital anomalies of the kidney and urinary tract: a propensity-score-matched analysis with case-control design

BACKGROUND

We compared long-term outcomes after kidney transplantation (KTx) in patients with and without congenital anomalies of the kidney and urinary tract (CAKUT).

METHODS

KTx recipients (KTRs) with CAKUT in 1980-2016 were identified; their hard copy and electronic medical records were reviewed and compared to a propensity-score-matched control group (non-CAKUT) from the same period. The primary outcomes were graft loss or death with a functioning graft; secondary outcomes included posttransplant urinary tract infections (UTIs) and biopsy-proven rejection (BPR).

RESULTS

: We identified 169 KTRs with CAKUT and 169 matched controls. Median follow-up was 132 (IQR: 75.0-170.0) months. UTIs were more common in CAKUT patients compared to non-CAKUT group (20.7% vs 10.7%; p = 0.01). Rates of BPR were similar between the two groups. In Kaplan-Meier analysis, 10-year graft survival rates were significantly higher in the CAKUT group than in the non-CAKUT group (87.6% vs 69.2%; p < 0.001), while patient survival rates were similar. In multivariate Cox regression analyses, CAKUT (HR: 0.469; 95% CI: 0.320-0.687; p < 0.001) and PRA positivity before transplantation (HR: 3.756; 95% CI: 1.507-9.364; p = 0.005) predicted graft loss.

DISCUSSION

Graft survival in KTRs with CAKUT appears superior to KTRs without CAKUT. Transplant centers should develop multidisciplinary educational and social working groups to support and encourage CAKUT patients with kidney failure to seek for transplants.

Follow-up of children and adolescents with congenital anomalies of the kidneys and urinary tract, associated with rare hereditary syndromes

The purpose of the study was to evaluate the course and outcome in chronic kidney disease of congenital anomalies of the kidneys and urinary tract (CAKUT) associated with rare hereditary syndromes in children and adolescents, and to compare the results with literature data. The results of a follow-up study of the course and outcome in chronic kidney disease with syndromal congenital anomalies of the kidneys and urinary tract in rare hereditary syndromes (Pierson, Fraser 1 type, Renal hypodysplasia/ aplasia 3 type, Schuurs– Hoeómakers, CHARGE, Lowe, Renal-Coloboma, VACTERL association) and chromosomal abnormalities (Shereshevsky—Terner monosomia 45‡) are presented. In 4 out of 9 children and adolescents with congenital anomalies of the kidneys and urinary tract with rare hereditary syndromes, the formation of chronic kidney disease was established.

Urodynamic changes before and after endoscopic valve ablation in boys diagnosed with the posterior urethral valve without chronic renal failure

INTRODUCTION

Current research on the posterior urethral valve (PUV) mainly focuses on the follow-up of bladder function after valve ablation. However, few studies exist on the changes in bladder function before and after valve ablation.

OBJECTIVES

To investigate the urodynamic changes before and after PUV ablation and determine the effect of operation on bladder function, in patients.

MATERIALS AND METHODS

The clinical records of 38 boys diagnosed with PUV and undergone urodynamic exams before and after valve ablation were retrospectively reviewed. In addition, differences in patients' radiographic studies and urodynamic characteristics between pre- and post-operation were evaluated. Moreover, the urodynamic data was compared using the paired t-test and all the data was expressed as means ± SEM. Additionally, p values less than 0.05 were considered to be statistically significant.

RESULTS

All the patients were diagnosed with PUV and the follow-up period after operation ranged between 9 and 114 months. The urodynamic exams were performed about 6 months after operation. The results revealed that bladder compliance improved from 8.49 ± 4.73 to 13.31 ± 6.78 ml/cmH₂O while the maximum detrusor pressure decreased from 95.18 ± 37.59 to 50.71 ± 21.71 cmH₂O, after valve ablation. Additionally, there were significant differences in the pre- and post-operation values of bladder compliance and maximum detrusor pressure (p < 0.05). However, there were no significant differences in the pre- and post-operation values with regard to the residual urine volume, maximum bladder volume and maximum urinary flow rate (p > 0.05).

CONCLUSIONS

The adequacy of the COPUM incision is necessary. But the study showed that endoscopic valve ablation couldn't by itself completely improve the bladder function of patients diagnosed with PUV. However, it was able to improve bladder compliance and decrease maximum detrusor pressure to a certain extent. However, bladder compliance still couldn't reach the normal level.

MEDIUM AND LONG-TERM CLINICAL OUTCOMES OF KIDNEY TRANSPLANTATION IN PATIENTS WITH PRUNE BELLY SYNDROME: A SINGLE-CENTRE EXPERIENCE

OBJECTIVES

To present the medium and long-term outcomes of kidney transplantation performed in patients with Prune Belly Syndrome (PBS) which is one of the congenital anomalies of the kidney and urinary tract (CAKUT).

METHODS

Thirteen kidney transplantations were performed in nine patients with PBS from January 1994 to December 2020. Demographics, surgical features, graft and patient survival rates were analysed. Survival outcomes was compared with 106 age- and donor-type matched controls who underwent transplantation because of non-urological causes.

RESULTS

The median ages of PBS patients at the time of first and second transplantation were 19 and 34 years old, respectively. One patient had postoperative Clavien grade 3a complication. Eight of 13 transplants are still functional at the last follow-up. Eight patients underwent pre-transplant urological operations in preparation for kidney transplantation, while four patients underwent urological operations in the post-transplant period. Graft survival for PBS transplants at 5, 10 and 15 years were 90.9%, 57.7% and 38.5%, respectively. Graft survival for control cohort at 5, 10 and 15 years were 89.9%, 80% and 74%, respectively. The patient and graft survival rates were similar between PBS and control groups (p=0.449, p=0.134, respectively).

CONCLUSION

This single-centre study showed that the medium term graft survival rates in patients with PBS are encouraging and comparible to non-CAKUT transplant patients, however long-term graft survival rates were found to be proportionally inferior. To help determine the reasons for long-term transplant kidney function deterioration and how to improve them we suggest that multi-centre international collaboration will be needed.

Chronic Kidney Disease in Boys with Posterior Urethral Valves-Pathogenesis, Prognosis and Management

Posterior urethral valves (PUV) are the most common form of lower urinary tract obstructions (LUTO). The valves can be surgically corrected postnatally; however, the impairment of kidney and bladder development is irreversible and has lifelong implications. Chronic kidney disease (CKD) and bladder dysfunction are frequent problems. Approximately 20% of PUV patients will reach end-stage kidney disease (ESKD). The subvesical obstruction in PUV leads to muscular hypertrophy and fibrotic remodelling in the bladder, which both impair its function. Kidney development is disturbed and results in dysplasia, hypoplasia, inflammation and renal fibrosis, which are hallmarks of CKD. The prognoses of PUV patients are based on prenatal and postnatal parameters. Prenatal parameters include signs of renal hypodysplasia in the analysis of fetal urine. Postnatally, the most robust predictor of PUV is the nadir serum creatinine after valve ablation. A value that is below 0.4 mg/dl implies a very low risk for ESKD, whereas a value above 0.85 mg/dl indicates a high risk for ESKD. In addition, bladder dysfunction and renal dysplasia point towards an unbeneficial kidney outcome. Experimental urinary markers such as MCP-1 and TGF-β, as well as microalbuminuria, indicate progression to CKD. Until now, prenatal intervention may improve survival but yields no renal benefit. The management of PUV patients includes control of bladder dysfunction and CKD treatment to slow down progression by controlling hypertension, proteinuria and infections. In kidney transplantation, aggressive bladder management is essential to ensure optimal graft survival.

The causes and consequences of paediatric kidney disease on adult nephrology care

Adult nephrologists often look after patients who have been diagnosed with kidney disease in childhood. This does present unique challenges to the adult nephrologist, who may be unfamiliar with the underlying cause of kidney disease as well as the complications of chronic kidney disease (CKD) that may have accumulated during childhood. This review discusses common causes of childhood CKD, in particular congenital anomalies of the kidney and urinary tract (CAKUT), autosomal dominant tubulointerstitial kidney disease (ADTKD), polycystic kidney disease, hereditary stone disease, nephrotic syndrome and atypical haemolytic uraemic syndrome. The long-term consequences of childhood CKD, such as the cardiovascular consequences, cognition and education as well as bone health, nutrition and growth are also discussed.

Pearls and Pitfalls in Pediatric Kidney Transplantation After 5 Decades

Worldwide, over 1,300 pediatric kidney transplantations are performed every year. Since the first transplantation in 1959, healthcare has evolved dramatically. Pre-emptive transplantations with grafts from living donors have become more common. Despite a subsequent improvement in graft survival, there are still challenges to face. This study attempts to summarize how our understanding of pediatric kidney transplantation has developed and improved since its beginnings, whilst also highlighting those areas where future research should concentrate in order to help resolve as yet unanswered questions. Existing literature was compared to our own data of 411 single-center pediatric kidney transplantations between 1968 and 2020, in order to find discrepancies and allow identification of future challenges. Important issues for future care are innovations in immunosuppressive medication, improving medication adherence, careful donor selection with regard to characteristics of both donor and recipient, improvement of surgical techniques and increased attention for lower urinary tract dysfunction and voiding behavior in all patients.

Fetal therapy of LUTO (lower urinary tract obstruction) - a follow-up observational study

PURPOSE

Fetal megacystis (MC) can be severe and is mainly caused by fetal lower urinary tract obstruction (LUTO). Mortality of fetal LUTO can be high as a result of pulmonary hypoplasia and/or (chronic) renal insufficiency. Several technical procedures for vesicoamniotic shunting (VAS) were developed to improve fetal MC outcomes.

MATERIAL AND METHODS

We present the outcome of nine fetuses with MC who received VAS in the prenatal period (14 + 6 to 27 + 6 weeks GA) using the Somatex^® intrauterine shunt system. MC was defined as an increased longitudinal measurement of the bladder >15 mm. The median follow-up time after birth was 18 months.

RESULTS

Eight Fetuses had uncomplicated VAS intervention. One case developed PPROM 24 h after VAS leading to abortion. Pregnancy was later terminated in further two cases. All six live-born infants received intensive care treatment. Invasive-mechanical ventilation was necessary in one case who died 24 h post-partum of severe cardiac depression. Five infants who survived the follow-up time developed chronic renal insufficiency (CRI), with one infant developing end-stage renal failure requiring peritoneal dialysis.

CONCLUSION

Overall, 5 of 9 LUTO fetuses (55%) undergoing VAS with the Somatex^® intrauterine shunt system showed long-term survival beyond the neonatal period of 28 d (5/9; 55%) with varying morbidity.

Long-term outcome of transplant ureterostomy in children: A National Review

BACKGROUND

CAKUT are the most common cause of end-stage renal failure in children (Pediatr Nephrol. 24, 2009, 1719). Many children with CAKUT have poor urinary drainage which can compromise post-transplant outcome. Identifying safe ways to manage anatomical abnormalities and provide effective urinary drainage is key to transplant success. Much debate exists regarding optimum urinary diversion techniques. The definitive formation of a continent urinary diversion is always preferable but may not always be possible. We explore the role of ureterostomy formation at transplantation in a complex pediatric group.

METHODS

We report six pediatric patients who had ureterostomy formation at the time of transplantation at the National Paediatric Transplant Centre in Dublin, Ireland. We compared renal function and burden of urinary tract infection to a group with alternative urinary diversion procedures and a group with normal bladders over a 5-year period.

RESULTS

There was no demonstrable difference in estimated glomerular filtration rate between the groups at 5-year follow-up. The overall burden of UTI was low and similar in frequency between the three groups.

CONCLUSIONS

Ureterostomy formation is a safe and effective option for temporary urinary diversion in children with complex abdominal anatomy facilitating transplantation; it is, however, important to consider the implications and risk of ureterostomy for definitive surgery after transplantation.

The current status of kidney transplantation in Nigerian children: still awaiting light at the end of the tunnel

BACKGROUND

Kidney transplantation (KT) is the gold standard treatment for children with chronic kidney disease stage 5 (CKD5). It is easily accessible in well-resourced countries, but not in low/middle-income countries (LMICs). We present, a multicentre experience of paediatric KT of children domiciled in Nigeria. We aim to highlight the challenges and ethical dilemmas that children, their parents or guardians and health care staff face on a daily basis.

METHODS

A multicentre survey of Nigerian children who received KTs within or outside Nigeria from 1986 to 2019 was undertaken using a questionnaire emailed to all paediatric and adult consultants who are responsible for the care of children with kidney diseases in Nigeria. Demographic data, causes of CKD5, sources of funding, donor organs and graft and patient outcome were analysed. Using Kaplan-Meier survival analysis, we compared graft and patient survival.

RESULTS

Twenty-two children, aged 4-18 years, received 23 KTs, of which 12 were performed in Nigeria. The male-to-female ratio was 3.4:1. Duration of pre-transplant haemodialysis was 4-48 months (median 7 months). Sixteen KTs were self-funded. State governments funded 3 philanthropists 4 KTs. Overall differences in graft and patient survival between the two groups, log rank test P = 0.68 and 0.40, respectively were not statistically significant.

CONCLUSIONS

The transplant access rate for Nigerian children is dismal at < 0.2%. Poor funding is a major challenge. There is an urgent need for the federal government to fund health care and particularly KTs. Graphical Abstract.

Renal Transplants Due to Congenital Anomalies of the Kidney and Urinary Tract (CAKUT) Have Better Graft Survival Than Non-CAKUT Controls: Analysis of Over 10,000 Patients

OBJECTIVE

To determine whether graft survival for patients with congenital anomalies of the kidney and urinary tract (CAKUT) is impaired compared to non-CAKUT counterparts.

METHODS

The United States Renal Data System (USRDS) is a national data system that has collected information about end stage renal disease (ESRD) and renal transplantation since 1995. We identified 10,635 first-time renal transplant patients with ESRD attributed to a CAKUT diagnosis transplanted between 1995 and 2018, with follow-up of 7.9 ± 5.8 years. We matched 1:1 with non-CAKUT transplant recipients, using age at transplant, sex, race, year of transplant, and donor-type. We compared renal transplant death-censored graft survival between CAKUT vs non-CAKUT controls, with further stratification for age at transplant and lower urinary tract malformations (LUTM) vs upper urinary tract malformations (UUTM).

RESULTS

Graft survival was better in CAKUT patients with a 5-year survival of 83.3% vs 79.3% (P< .001), and CAKUT status infers a hazard ratio of 0.878 for graft failure on multivariable analysis with Cox regression. Favorability of CAKUT status persisted when stratifying for both pediatric (80.3 vs 77.6% P< .001) and adult (84.5 vs 81.4% P< .001) age groups. Looking within the CAKUT population: comparison of LUTM to UUTM yielded no difference, implying that LUTM is not a risk factor for graft failure. Examining pediatric LUTM alone, graft survival was not better than matched non-CAKUT counterparts with 5-year graft survival of 69%-75% for LUTM adolescents.

CONCLUSION

Renal transplant graft survival is better overall in CAKUT patients as opposed to non-CAKUT counterparts. Pediatric LUTM patients have similar graft survival to controls.

Long-Term Renal Transplant Outcome in Patients With Posterior Urethral Valves. Prognostic Factors Related to Bladder Dysfunction Management

Introduction: To obtain a successful renal transplant (RT) outcome in patients with posterior urethral valves (PUV), it is necessary to accomplish an adequate bladder dysfunction treatment. Our aim was to determine prognostic factors related to bladder dysfunction management in long-term RT outcome in patients with PUV. Methods: A retrospective review of patients with PUV who received a first RT after 1985 in our institution with at least 5 years of follow-up was performed. Variables analyzed included prenatal diagnosis, age of diagnosis, initial presentation and management, bladder dysfunction treatment, other surgical treatments, pre-transplant dialysis, age of transplantation, type of donor, immunosuppression regimen, vascular and urological complications, rejections episodes, and graft survival. Results: Fifty-one patients were included in the analysis. Prenatal diagnosis was done in 37.3%. Median age of diagnosis was 0.30 (0-88) months. Initial presentation was vesicoureteral reflux (VUR) in 78% and obstructive ureterohydronefrosis in 35.3%. Initial management was valve ablation (29.4%), pyelo-ureterostomy (64.7%), and vesicostomy (5.9%). In 33.3%, a type of bladder dysfunction treatment was performed: 21.6% bladder augmentation (BA), 15.7% Mitrofanoff procedure, 17.6% anticholinergic drugs, and 27.5% clean intermittent catheterization (CIC). Pre-transplant dialysis was received by 66.7%. Transplantation was performed at 6.28 ± 5.12 years, 62.7% were cadaveric and 37.3% living-donor grafts. Acute rejection episodes were found in 23.6%. Urological complications included recurrent urinary tract infections (UTIs) (31.4%); native kidneys VUR (31.4%); graft VUR (45.1%); and ureteral obstruction (2%). Vascular complications occurred in 3.9%. Mean graft survival was 11.1 ± 6.9 years. Analyzing the prognostic factor that influenced graft survival, patients with had CIC or a Mitrofanoff procedure had a significant better long-term graft survival after 10 years of follow-up (p < 0.05), despite of the existence of more recurrent UTIs in them. A better graft survival was also found in living-donor transplants (p < 0.05). No significant differences were observed in long-term graft survival regarding native kidneys or graft VUR, BA, immunosuppression regimen, or post-transplant UTIs. Conclusion: Optimal bladder dysfunction treatment, including CIC with or without a Mitrofanoff procedure, might result in better long-term graft survival in patients with PUV. These procedures were not related to a worse RT outcome in spite of being associated with more frequent UTIs.

Kidney transplantation in children with CAKUT and non-CAKUT causes of chronic kidney disease: Do they have the same outcomes?

Almost half the children who undergo kidney transplantation (KTx) have congenital abnormalities of the kidney and urinary tract (CAKUT). We compared patient, graft survival, and kidney function at last follow-up between CAKUT and non-CAKUT patients after KTx. We divided the analysis into two eras: 1988-2000 and 2001-2019. Of 923 patients, 52% had CAKUT and 48% non-CAKUT chronic kidney disease (CKD). Of the latter, 341 (77%) had glomerular disease, most frequently typical HUS (32%) and primary FSGS (27%); 102 had non-glomerular disease. CAKUT patients were more often boys, younger at KTx, transplanted more frequently preemptively, but with longer time on chronic dialysis. They had less delayed graft function (DGF) and better eGFR, but higher incidence of urinary tract infection (1 year post-KTx). In both eras, 1-, 5-, and 10-year patient survival was similar in the groups, but graft survival was better in CAKUT recipients vs those with primary glomerular and primary recurrent glomerular disease: Era 1, 92.3%, 80.7%, and 63.6% vs 86.9%, 70.6%, and 49.5% (P = .02), and 76.7%, 56.6%, and 34% (P = .0003); Era 2, 96.2%, 88%, and 73.5% vs 90.3%, 76.1%, and 61% (P = .0075) and 75.4%, 54%, and 25.2% (P < .0001), respectively. Main predictors of graft loss were DGF, late acute rejection (AR), and age at KTx in CAKUT group and disease relapse, DGF, early AR, and number of HLA mismatches in recipients with glomerular disease. Graft survival was better in CAKUT patients. DGF was the main predictor of graft loss in all groups. Disease recurrence and early AR predicted graft failure in patients with glomerular disease.

Comparative outcome analysis of pediatric kidney transplant in posterior urethral valves children with or without pretransplant Mitrofanoff procedure

BACKGROUND

Urinary diversion using catheterizable channel among posterior urethral valve (PUV) patients may help to alleviate the functional concerns of the bladder on the allograft. Herein, we review our series of PUV patients undergoing renal transplants at a single institution to determine outcomes between those with and without pretransplant Mitrofanoff.

METHODS

PUV cases in our transplant database from 2000 to 2017 were identified. Data collected included clinical demographics, presentation of PUV, bladder function, implementation of dialysis and donor type. Post-transplant variables included graft function, and bladder function including incontinence and UTI development. Comparison between with vs without pretransplant Mitrofanoff patient groups was performed using Fisher's exact and t test analysis.

RESULTS

Overall, 22 cases were analyzed. The majority (77%) had a prenatal diagnosis of PUV, and 23% had a symptomatic presentation. Pretransplant Mitrofanoffs were performed in 40.9% of cases. The overall age at transplant was 10 ± 5 years. Five percent experienced post-transplant incontinence and 23% UTIs. No difference between groups was noted in variables including age at transplant, the timing of PUV diagnosis. Mitrofanoff group patients had more symptomatic febrile UTIs than those without Mitrofanoff (67% vs 15%; P = .03); however, there was no difference in post-transplant UTI development. Furthermore, the Mitrofanoff group seems to have later onset of dialysis or need for transplant (age at the start of dialysis 36 ± 56 vs 156 ± 25 months, P < .001).

CONCLUSION

Our study suggests that patients with early PUV diagnoses who develop symptomatic UTI may benefit from early creation of a Mitrofanoff cathetherizable channel, which is associated with delayed ESRD progression and need for dialysis.

Lower Urinary Tract Dysfunction and Pediatric Renal Transplant

OBJECTIVES

Lower urinary tract abnormalities have been considered to be contraindications for renal transplant. However, advancements in diagnosis and treatment in this area have allowed renal transplant as a treatment choice in selected cases. We evaluated clinical outcomes of pediatric renal transplant in patients with lower urinary tract dysfunction.

MATERIALS AND METHODS

We retrospectively evaluated data from 165 pediatric renal transplant patients, and data were compared between patients with and without lower urinary tract dysfunction. Patient demographics, cause of chronic renal failure, acute rejection episodes, and graft loss were included in our analyses.

RESULTS

Seventeen patients had lower urinary tract dysfunction, and the remaining 148 patients had functional lower urinary tracts. Patients with lower urinary tract dysfunction were younger than the other patient group at diagnosis of chronic renal failure. The mean follow-up after renal transplant in the 2 groups was similar. Differences with regard to donor type, immunosuppressive treatment, and acute rejection episodes were not significant between the 2 groups. Eight patients had lost their grafts during follow-up; however, only 1 of these patients was in the lower urinary tract dysfunction group. Graft loss rate was similar between the groups.

CONCLUSIONS

Pediatric patients with lower urinary tract dysfunction had similar graft outcomes versus other pediatric renal transplant patients. Careful evaluation and preparation of the lower urinary tract are important factors for renal transplant success.