Pediatric kidney recipients with small capacity, defunctionalized urinary bladders receiving adult-sized kidney without prior bladder augmentation

A novel approach to bladder cycling for defunctionalized bladders prior to pediatric kidney transplantation: A case series

Ensuring a safe reservoir for pediatric renal transplantation into a defunctionalized bladder is a challenge faced by urologists. We present three patients with defunctionalized bladders who initiated bladder cycling utilizing overnight continuous saline infusion via enteral feeding pump for bladder salvage and subsequent transplantation.

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.

Utility of Pre-Transplant Bladder Cycling for Patients With a Defunctionalized Bladder. A Randomized Controlled Trial

OBJECTIVE

To study the necessity of pre-transplant programmed bladder cycling (PBC) in patients with defunctionalized bladder (DB).

METHOD

This RCT included renal transplant (RT) candidates with DB. Eligible patients were assigned to 2 groups, group I underwent PBC before RT and group II underwent direct RT into the DB. The primary outcome was to assess the efficacy of PBC in improving post- RT bladder capacity. Secondly, to compare its impact on early urological complications and 3-month voiding function and 1-year graft function and survival. Graft function was evaluated using serum creatinine and eGFR using MDRD equation.

RESULTS

Groups I included 23 patients and group II included 20 patients. The mean ±SD of bladder capacity was 88.7±11.7mL and 90.6 ±9.8mL in both groups, respectively (P = .5). In group I, PBC increased bladder capacity to 194.7 ±21.2 mL (P < .001). Targeted bladder capacity was achieved in 19 (82.6 %) patients and 2 patients developed UTI. At 3-months, bladder capacity, compliance and bladder contractility index improved significantly in both groups with a significant reduction in maximum detrusor pressure with no significant difference between both groups (P = .3,0.4, 0.2 and 0.8, respectively). Urinary leakage occurred in one (4.3%) and 3 patients (15%) in group 1 and 2, respectively (P = .2). At 1-year, no statistically significant differences in the median (IQR) serum creatinine (P = .05) and eGFR (P = .07) between both groups were noted.

CONCLUSION

Pre-transplant PBC for DB-patients provided no clinical advantage concerning post-operative urological complication, urodynamic criteria and graft function and survival.

Timing of reconstruction of the lower urinary tract in pediatric kidney transplant recipients: A CERTAIN multicenter analysis of current practice

BACKGROUND

Preexistent LUTD are considered a hostile environment, which might negatively impact KTx survival. In such cases, surgical reconstruction of the bladder is required. However, there is still disagreement on the optimal timing of the reconstruction procedure.

METHODS

This is a multicenter analysis of data from the CERTAIN Registry. Included were 62 children aged 8.18 ± 4.90 years, with LUTD. Study endpoints were the duration of initial posttransplant hospitalization, febrile UTIs, and a composite failure endpoint comprising decline of eGFR, graft loss, or death up to 5 years posttransplant. Outcome was compared to matched controls without bladder dysfunction.

RESULTS

Forty-one patients (66.1%) underwent pretransplant and 14 patients (22.6%) posttransplant reconstruction. Bladder augmentation was performed more frequently in the pretransplant (61%) than in the posttransplant group (21%, p = .013). Outcome in the pre- and posttransplant groups and in the subgroups of patients on pretransplant PD with major bladder surgery either pre- (n = 14) or posttransplant (n = 7) was comparable. Outcomes of the main study cohort and the matched control cohort (n = 119) were comparable during the first 4 years posttransplant; at year 5, there were more events of transplant dysfunction in the study cohort with LUTD than in controls (p = .03).

CONCLUSIONS

This multicenter analysis of the current practice of LUTD reconstruction in pediatric KTx recipients shows that pre- or posttransplant surgical reconstruction of the lower urinary tract is associated with a comparable 5-year outcome.

Is anuria prior to pediatric renal transplantation associated with poor allograft outcomes?

INTRODUCTION

Anuria from end-stage renal disease leads to a defunctionalized bladder and may pose technical challenges at the time of renal transplantation. Anuria's effect on bladder function after renal transplantation is considered to be minimal in adults, although a paucity of evidence is available in children. The purpose of this study was to examine the effects of anuria prior to pediatric renal transplantation for ESRD due to medical renal disease on allograft outcome.

METHODS

We performed a retrospective review of pediatric patients who underwent renal transplantation for medical renal disease at our institution between 2005 and 2016. Demographics and clinical data were assessed. We also compared GFR at 1 year post-transplant for medical renal patients with history of anuria and those without.

RESULTS

Twenty-one patients fulfilled our inclusion criteria with median duration of anuria was 10 months. Preoperative VCUG was available in five patients and their bladder capacity was 29% of expected bladder capacity for age (range 8%-41%). Anticholinergic therapy was prescribed in six patients (28%) for a mean duration of 5 months (range 1-16 months). Comparison of GFR at 1 year post-transplant in anuria group and those without anuria showed no difference (69 vs 75 mL/min, P = 0.37). No correlation was observed between duration of anuria and post-transplant GFR.

CONCLUSION

The majority of children in our pretransplant anuria cohort did not develop bladder dysfunction after renal transplantation. No difference was observed between GFR at 1 year when comparing anuric to non-anuric transplant recipients of medical renal disease etiology.

Outcomes of kidney transplants in pediatric patients with the vertebral defects, anal atresia, cardiac defects, tracheoesophageal fistula, renal anomalies, limb abnormalities association

In this single-center retrospective study, we analyzed kidney transplant outcomes in nine pediatric patients with VACTERL [vertebral defects, anal atresia, cardiac defects, tracheoesophageal fistula, renal anomalies, limb abnormalities] association-making this the largest study of its kind. Of 743 pediatric kidney transplant recipients at our center (1980-2017), nine had documented diagnoses of VACTERL association. All nine had congenital anorectal malformations and renal anomalies, five had vertebral defects, and one had a bifid thumb and tracheoesophageal fistula. Renal anomalies included dysplasia (n = 6), aplasia (n = 3), and horseshoe kidney (n = 2). Congenital lower urinary tract anomalies included neurogenic bladder (n = 6), obstructive uropathy (n = 4), anovesicular fistula (n = 1), rectourethral fistula (n = 1), and posterior urethral valves (n = 1). Age at transplant ranged from 1.2 to 15 years (mean, 7.3; standard deviation [SD], 5.5); 6 (67%) were male, and 3 (33%) were female; 6 (67%) had a living related donor, and 3 (33%) had a deceased donor. The overall graft survival rate was 78% (range, 1.5 to 25.2 years; mean, 10.5; SD, 8.9). One month post-transplant, one recipient died with a functioning graft. At 3.7 years post-transplant, one graft failed because of recurrent pyelonephritis. Post-transplant urologic complications included pyelonephritis (n = 6), vesicoureteral reflux (n = 5), and graft hydronephrosis (n = 4). We conclude that pediatric patients with VACTERL association can be safely transplanted-careful patient selection with vigilance and intervention for pre- and post-transplant urologic complications is essential.

When does vesicoureteral reflux in pediatric kidney transplant patients need treatment?

PURPOSE

The treatment of VUR in children with UTI has changed significantly, due to studies showing that antibiotic prophylaxis does not decrease renal scarring. As children with kidney transplants are at higher risk for UTI, we investigated if select patients with renal transplant VUR could be managed without surgery.

MATERIALS AND METHODS

A total of 18 patients with VUR into their renal grafts were identified, and 319 patients underwent transplantation from 2006 to 2016. The cause for the detection of the VUR, treatment, and graft function was reviewed.

RESULTS

Six boys and 12 girls were identified, 13 of whom had grade 3 or 4 VUR into the renal graft. Nine patients presented with hydronephrosis or abnormal renal biopsy: eight were successfully managed with antibiotic prophylaxis and bladder training, one developed UTI and underwent Dx/HA subureteric injection. Nine patients presented with recurrent febrile UTI, only one was successfully managed without surgery. Only 2 of 9 (22%) patients who underwent Dx/HA injection had resolution of their reflux. Of the remaining seven, five required open ureteral reimplantation (two for obstruction), one lost the graft due to rejection, and one had significant hydronephrosis. eGFR was similar between the hydronephrosis, UTI, and abnormal renal biopsy groups at all times.

CONCLUSION

Patients with transplant VUR and recurrent febrile UTI are more likely to require surgical therapy, but the complication and failure rate for Dx/HA injection is significant. Patients with transplant VUR without febrile UTI can be successfully managed with bladder training and temporary antibiotic prophylaxis.

Pretransplant defunctionalized bladder-overrated condition?

AIMS

The objective of this study was to evaluate the expression of bladder receptors in patients with defunctionalized bladder (DB) and to assess voiding behavior after refunctionalization.

METHODS

A total of 68 pretransplant patients were divided in two groups: DB (diuresis <300 mL/24 h; n = 33) and NDB (non-DB; diuresis ≥300 mL/24 h; n = 35). A sample of mucosa and detrusor at the site of the future ureteral implantation was collected. The following receptors were assessed by real-time polymerase chain reaction (qRT-PCR): M₂ , M₃ , α_1D , β₃ , P2X₂ , P2X₃ , TRPV1, TRPV4, TRPA1, and TRPM8. At 3, 6, and 12 months after transplant patients answered IPSS and ICIQ-OAB questionnaires and filled a 3-day 24 h frequency/volume chart (FVC) at 6 and 12 months.

RESULTS

The expression of all receptors in the mucosa and in the detrusor was similar in both groups, except from α_1D , which was overexpressed in the detrusor of DB relatively to NDB group. ICIQ-OAB symptom score was similar between the groups at 3, 6, and 12 months. There was a reduction of this score in both groups with time. The same pattern was found for IPSS score. Bother scores were similar between groups. No difference was observed for all FVC parameters between DB and NDB patients.

CONCLUSION

Gene expression of bladder receptors involved in micturition control was similar in patients with or without DB. Bladder behavior had a similar pattern independently of pretransplant residual diuresis. These findings question the relevance of the term DB in pretransplant patients.

Anuria since birth: does it impact outcome of kidney transplant in infants?

Kidney transplantation (txp) in infants has recently made much progress but provides a unique challenge in infants anuric since birth. Little data exists on outcome of renal txp recipients with anuria since birth. Retrospective chart review was done for outcome of 27 children with wt ≤15 kg and they were divided into two groups: Group A (N=21) with urine output and Group B (N=6) anuric since birth had their urological complications and long-term outcome compared. Median age at the time of txp 18 vs 23 months, mean wt 10.8 vs 11.8 kg, and mean ht 77 cm in both, mean follow-up post-txp: 9.4 vs 5.6 years, and neurological problems were noted in 48% and 33% in Group A and Group B. There was no graft thrombosis or post-transplant lymphoproliferative disease and only two rejections. Anuric Group B were older, had more post-txp urological surgeries (66% vs 19%) and UTIs (66% vs 38%) compared to Group A. The overall graft survival at 1, 5, and 10 years was 96%, 86%, and 70%; patient survival at 1, 5, and 10 years was 96%, 85%, and 85%. Long-term graft outcomes in small children, anuric prior to txp, were excellent despite higher rates for UTIs and urological complications.

Kidney transplant in pediatric patients with severe bladder pathology

The aim of the current study was to compare results in pediatric renal transplantation of patients with and without SBP. Between 2001 and 2013, a total of 168 kidney transplants were performed at our center. A retrospective analysis was performed and recipients were divided into two groups: NB and SBP. Incidence of surgical complications after procedure, and graft and patient survival were evaluated. A total of 155 recipients (92%) with complete data were analyzed, and 13 recipients that had had previous bladder surgeries were excluded (11 with VUR surgery and two with previous kidney transplants), of the 155 recipients: 123 (79%) patients had NB, and 32 (21%) patients had SBP, with a median follow-up of 60 (1-137) and 52 (1-144) months, respectively. Among post-transplant complications, UTI (68.8% vs. 23%, p < 0.0001) and symptomatic VUR to the graft (40.6% vs. 7.3%, p < 0.0001) were significantly higher in the SBP group. There was no significant difference in overall graft and patient survival between groups. Renal transplantation is safe in pediatric recipients with SBP; however, urologic complications such as UTI and VUR were significantly higher in this group. Graft and patient survival was similar in SBP and NB groups.

Vascular anastomosis for paediatric renal transplantation and new strategy in low-weight children

The technical aspects of RT in low-weight children should be specific, particularly with regard to VA. This retrospective study assesses the main VA options in paediatric RTs and proposes a new strategy for renal artery trajectory when using the Ao and the right iVC. The sample included 81 patients and was categorized into a group of children weighing <16 kg and the other group of children weighing 16 kg or more. The smaller children received the graft predominantly on the Ao and iVC (63%); however, the VA options varied in children weighing more than 16 kg, with anastomoses predominantly to the common iliac vessels (46%). In the first group, when the Ao was the selected vessel for anastomosis on the right side, the trajectory adopted for the transplanted kidney artery was posterior to the iVC. This strategy may reduce the risk of compression of the iVC by the renal artery of the donor kidney and may reconstitute the normal anatomy of the renal artery. Moreover, it did not represent a risk factor for graft loss in this sample.

Improvement of urinary dysfunction after kidney transplantation by administration of the antimuscarinic agent--prospective randomized controlled study

BACKGROUND

Bladder dysfunction after kidney transplantation (KTx) impairs the patients' quality of life. We examined the bladder function status perioperatively in patients undergoing KTx and performed a randomized prospective study to determine the efficacy of an antimuscarinic agent, solifenacin, in ameliorating the bladder dysfunction after KTx.

METHODS

The subjects in this study were 33 patients who underwent KTx at our institution. The patients were divided into two groups: group 1 (n=18), composed of patients who were not treated with any antimuscarinic agent, and group 2 (n=15), composed of patients treated with an antimuscarinic agent. We investigated the actual bladder function status of these patients before and after KTx by the following two methods: (1) video water cystometry and (2) questionnaire study using the Overactive Bladder Symptom Score and King's Health Questionnaire.

RESULTS

The cystometry study revealed a significantly greater increase of the maximum cystometric capacity in group 2 than in group 1 (173.0±60.7 mL in group 1 and 260.1±51.0 mL in group 2 [P=0.005]) after KTx. In the questionnaire surveys, the decreases in the scores for all domains were observed 6 weeks after KTx. The scores in group 2 tended to be lower than those in group 1.

CONCLUSION

In all of our patients, the bladder dysfunction status improved dramatically after KTx. In addition, our results suggest that administration of the antimuscarinic agent, solifenacin, may contribute to improvement of the quality of life of patients undergoing KTx.