Impact of gastrointestinal and urological symptoms in children with myotonic dystrophy type 1.

Gastrointestinal and urological symptoms are frequently reported by people with myotonic dystrophy type 1 (DM1) but have remained understudied. In a cross-sectional study, frequency, nature, treatment and impact of gastrointestinal and urological symptoms in children with DM1 aged 5-18 years were assessed. We included 58 children (30 males, 28 females) with a mean age of 13 years; 74.1 % reported at least one gastrointestinal symptom. Abdominal pain was the most frequently reported symptom (51.7 %), followed by dysphagia (41.8 %), diarrhoea (36.2 %), encopresis (36.0 %), constipation (32.7 %), bloating and flatulence (both 25.9 %). The most frequently reported urological symptoms were difficulty with toilet training (59.3 %), urinary incontinence (22.0 %), enuresis nocturna (10.3 %) and voiding (23.5 % hesitancy, 4.8 % intermittency and 13.8 % dysuria). The majority considered urological and gastrointestinal symptoms to have a negative influence on their daily life; 22.4 % of parents reported severe influence on daily family life (shame, social restrictions, school absence and concerns for their children's future). Considering the high prevalence of urological and gastrointestinal symptoms in children with DM1 and their influence on daily life it is key to correctly recognize, diagnose and treat these symptoms. We recommend screening for gastrointestinal and urological symptoms in the standard of care for children with DM1.

Challenges in e-Health: The effect of digitalisation of frequency voiding charts on compliance in paediatric patients. Randomised controlled trial comparing digital and versus paper frequency voiding charts.

Objective: Frequency voiding charts are commonly used to gain better insight into the voiding and drinking behaviours of patients with voiding symptoms. Non-compliance when filling out a chart is known to be high. The use of a digital application might increase adherence, but little research has been conducted on this topic. The aim of this study is to compare the quality (number of correctly filled out charts) and quantity (number of complete charts) of digital versus paper frequency voiding charts among children and their parents. Methods: A multi-centre parallel randomised controlled trial was conducted. Participants were assigned either a 48-h digital frequency voiding chart or a 48-h paper frequency voiding chart. Completion rates were scored based on a predefined scoring method and transcribed into a percentage. Secondary objectives included user friendliness, feasibility, degree of the child's participation, and attractiveness. Trail registry data: NTR NL9383. Results: Ninety-seven patients were randomised to either a digital (N = 53) or paper (N = 44) frequency voiding chart. No significant difference in complete and accurately filled out frequency voiding charts was seen between the groups, with 35% (N = 18) for digital and 50% (N = 22) for paper, p = 0.12. Subjects considered the digital application more appealing, more educative, and more inviting compared to the paper chart (p < 0.05). Conclusions: In this underpowered study, no significant difference appeared between the groups in the number of complete and accurately filled out frequency voiding charts. Implementation of e-health did not seem to improve compliance. In daily practice, personal preference might offer the best solution.

A pre-transplantation risk assessment tool for graft survival in Dutch pediatric kidney recipients.

Background: A prediction model for graft survival including donor and recipient characteristics could help clinical decision-making and optimize outcomes. The aim of this study was to develop a risk assessment tool for graft survival based on essential pre-transplantation parameters. Methods: The data originated from the national Dutch registry (NOTR; Nederlandse OrgaanTransplantatie Registratie). A multivariable binary logistic model was used to predict graft survival, corrected for the transplantation era and time after transplantation. Subsequently, a prediction score was calculated from the ß-coefficients. For internal validation, derivation (80%) and validation (20%) cohorts were defined. Model performance was assessed with the area under the curve (AUC) of the receiver operating characteristics curve, Hosmer-Lemeshow test and calibration plots. Results: In total, 1428 transplantations were performed. Ten-year graft survival was 42% for transplantations before 1990, which has improved to the current value of 92%. Over time, significantly more living and pre-emptive transplantations have been performed and overall donor age has increased (P < .05).The prediction model included 71 829 observations of 554 transplantations between 1990 and 2021. Other variables incorporated in the model were recipient age, re-transplantation, number of human leucocyte antigen (HLA) mismatches and cause of kidney failure. The predictive capacity of this model had AUCs of 0.89, 0.79, 0.76 and 0.74 after 1, 5, 10 and 20 years, respectively (P < .01). Calibration plots showed an excellent fit. Conclusions: This pediatric pre-transplantation risk assessment tool exhibits good performance for predicting graft survival within the Dutch pediatric population. This model might support decision-making regarding donor selection to optimize graft outcomes. Trial registration: ClinicalTrials.gov Identifier: NCT05388955.

Maternal risk factors for posterior urethral valves.

Introduction: Posterior urethral valves (PUV) is a congenital disorder causing an obstruction of the lower urinary tract that affects approximately 1 in 4,000 male live births. PUV is considered a multifactorial disorder, meaning that both genetic and environmental factors are involved in its development. We investigated maternal risk factors for PUV. Methods: We included 407 PUV patients and 814 controls matched on year of birth from the AGORA data- and biobank and three participating hospitals. Information on potential risk factors (family history of congenital anomalies of the kidney and urinary tract (CAKUT), season of conception, gravidity, subfertility, and conception using assisted reproductive techniques (ART), plus maternal age, body mass index, diabetes, hypertension, smoking, and use of alcohol and folic acid) was derived from maternal questionnaires. After multiple imputation, adjusted odds ratios (aORs) were estimated using conditional logistic regression corrected for minimally sufficient sets of confounders determined using directed acyclic graphs. Results: A positive family history and low maternal age (<25 years) were associated with PUV development [aORs: 3.3 and 1.7 with 95% confidence intervals (95% CI) 1.4-7.7 and 1.0-2.8, respectively], whereas higher maternal age (>35 years) was associated with a lower risk (aOR: 0.7 95% CI: 0.4-1.0). Maternal preexisting hypertension seemed to increase PUV risk (aOR: 2.1 95% CI: 0.9-5.1), while gestational hypertension seemed to decrease this risk (aOR: 0.6 95% CI: 0.3-1.0). Concerning use of ART, the aORs for the different techniques were all above one, but with very wide 95% CIs including one. None of the other factors studied were associated with PUV development. Conclusion: Our study showed that family history of CAKUT, low maternal age, and potentially preexisting hypertension were associated with PUV development, whereas higher maternal age and gestational hypertension seemed to be associated with a lower risk. Maternal age and hypertension as well as the possible role of ART in the development of PUV require further research.

The strengths and complexities of European registries concerning paediatric kidney transplantation health care.

Introduction: Patient data are increasingly available in (multi)national registries, especially for rare diseases. This study aims to provide an overview of current European registries of paediatric kidney transplantation (PKT) care, their coverage, and their focus. Based on these data, we assess whether the current status is optimal for achieving our common goal: the optimalisation of health care. Methods: A list of all PKT centres within the European Union (EU) as well as active PKT registries was compiled using existing literature and the European Platform on Rare Disease Registration. Registry staff members were contacted to obtain information about the parameters collected and the registry design. These data were compared between registries. Results: In total, 109 PKT centres performing PKT surgery were identified in the 27 EU Member States. Currently, five European PKT registries are actively collecting data. In 39% of these centres, no data were registered within any of these five existing international registries. A large variety was observed in the number of patients, centres, and countries involved in the registries. Furthermore, variability existed regarding the inclusion criteria, definitions used, and parameters collected. Collection of perioperative urologic data are currently underrepresented in the registries. Discussion: Currently, multiple registries are collecting valuable information in the field of PKT, covering the majority of PKT centres in Europe. Due to a large variety in the parameters collected as well as different focuses, data collection is currently fragmented and suboptimal; therefore, the current existing data are incomplete. In addition, a considerable proportion of the transplantation centres do not enter data in any international registry. Combining available information and harmonising future data collection could empower the aim of these registries-namely increasing insights into the strengths and potential of current care and therefore improve healthcare.

Genome-wide association study in patients with posterior urethral valves.

Congenital lower urinary tract obstructions (LUTO) are most often caused by posterior urethral valves (PUV), a male limited anatomical obstruction of the urethra affecting 1 in 4,000 male live births. Little is known about the genetic background of PUV. Here, we report the largest genome-wide association study (GWAS) for PUV in 4 cohorts of patients and controls. The final meta-analysis included 756 patients and 4,823 ethnicity matched controls and comprised 5,754,208 variants that were genotyped or imputed and passed quality control in all 4 cohorts. No genome-wide significant locus was identified, but 33 variants showed suggestive significance (P < 1 × 10-5). When considering only loci with multiple variants residing within < 10 kB of each other showing suggestive significance and with the same effect direction in all 4 cohorts, 3 loci comprising a total of 9 variants remained. These loci resided on chromosomes 13, 16, and 20. The present GWAS and meta-analysis is the largest genetic study on PUV performed to date. The fact that no genome-wide significant locus was identified, can be explained by lack of power or may indicate that common variants do not play a major role in the etiology of PUV. Nevertheless, future studies are warranted to replicate and validate the 3 loci that yielded suggestive associations.

Posterior Tibial Nerve Stimulation in Children with Lower Urinary Tract Dysfunction: A Mixed-Methods Analysis of Experiences, Quality of Life and Treatment Effect.

BACKGROUND: Posterior tibial nerve stimulation (PTNS) is one of the treatment modalities for children with therapy-refractory lower urinary tract dysfunction (LUTD). This study used a mixed-methods analysis to gain insight into the experiences of children treated with PTNS and their parents, the effect of treatment on quality of life (QOL) and the effect of PTNS on urinary symptoms. METHODS: Quantitative outcomes were assessed through a single-centre retrospective chart analysis of all children treated with PTNS in a group setting between 2016-2021. Voiding parameters and QOL scores before and after treatment were compared. Qualitative outcomes were assessed by an explorative study involving semi-structured interviews transcribed verbatim and inductively analysed using the constant-comparative method. RESULTS: The data of 101 children treated with PTNS were analysed. Overall improvement of LUTD was seen in 42% and complete resolution in 10%. Average and maximum voided volumes significantly increased. QOL improved in both parents and children independent of the actual effect on urinary symptoms. Interviews revealed PTNS to be well-tolerated. Facilitating PTNS in a group setting led to feelings of recognition in both children and parents. CONCLUSIONS: PTNS is a good treatment in children with therapy-refractory LUTD and provides valuable opportunities for peer support if given in a group setting.

Compensatory Hypertrophy in Paediatric Patients with a Unilateral Ureteropelvic Junction Obstruction.

BACKGROUND: Compensatory hypertrophy is common in children with solitary functioning kidney, but it is unknown whether it also develops in children with unilateral partial reduction of kidney function. OBJECTIVE: The aim of this study was to assess whether children with a unilateral ureteropelvic junction obstruction (UPJO) show compensatory growth of the unaffected kidney. Furthermore, we investigated whether the length of the unaffected kidney was related to the degree of split kidney function lost and other possible risk factors. Lastly, we studied a possible relationship with signs of kidney injury. DESIGN SETTING AND PARTICIPANTS: We retrospectively analysed clinical information from 194 children with a unilateral UPJO who participated in the Aetiologic research into Genetic and Occupational/environmental Risk factors for Anomalies in children (AGORA) data- and biobank. Data on kidney length, split kidney function, and other factors possibly associated with kidney length were extracted from electronic patient records. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Pearson's correlation coefficients between the split kidney function and unaffected kidney length were calculated. Multivariable logistic regression analyses were performed to identify factors associated with kidney length and signs of kidney injury. RESULTS AND LIMITATIONS: Most children with a UPJO had an unaffected kidney length above the reference for age at the end of follow-up (median age 6.5 yr). A correlation with split kidney function was present only in children with a split kidney function of ≥60% in the unaffected kidney (r = 0.41). Aside from split kidney function, UPJO side was the only determinant of kidney length, while no associations between kidney length and kidney injury were identified. CONCLUSIONS: Compensatory growth was visible in most children with a UPJO after sufficient follow-up time and was correlated with split kidney function in children with a severe UPJO. Contralateral kidney length provided no clear prognostic value for developing kidney injury. Studies with more patients and additional biomarkers of kidney injury are needed to further personalise care. PATIENT SUMMARY: Children with obstruction of urine outflow in one kidney often had a larger contralateral kidney. However, the size of this kidney could not be used to predict which children would develop kidney injury.

CDH12 as a Candidate Gene for Kidney Injury in Posterior Urethral Valve Cases: A Genome-wide Association Study Among Patients with Obstructive Uropathies.

BACKGROUND: Posterior urethral valves (PUVs) and ureteropelvic junction obstruction (UPJO) are congenital obstructive uropathies that may impair kidney development. OBJECTIVE: To identify genetic variants associated with kidney injury in patients with obstructive uropathy. DESIGN SETTING AND PARTICIPANTS: We included 487 patients born in 1981 or later who underwent pyeloplasty or valve resection before 18 yr of age in the discovery phase, 102 PUV patients in a first replication phase, and 102 in a second replication phase. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Signs of kidney injury were defined as dialysis, nephrectomy, kidney transplantation, estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m2, high blood pressure, antihypertensive medication use, proteinuria, and/or one kidney functioning at <45%. We used χ2 tests to calculate p values and odds ratios for >600 000 single-nucleotide polymorphisms (SNPs) in the discovery sample comparing patients with and without signs of kidney injury within 5 yr after surgery. We performed stratified analyses for PUV and UPJO and Kaplan-Meier and Cox regression analyses in the discovery and two replication samples for the associated SNPs, and RNA and protein expression analyses for the associated gene in fetal tissues. RESULTS AND LIMITATIONS: Despite the small and nonhomogeneous sample, we observed suggestive associations for six SNPs in three loci, of which rs6874819 in the CDH12 gene was the most clear (p = 7.5 × 10-7). This SNP also seemed to be associated with time to kidney injury in the PUV discovery and replication samples. RNA expression analyses showed clear CDH12 expression in fetal kidneys, which was confirmed by protein immunolocalization. CONCLUSIONS: This study identified CDH12 as a candidate gene for kidney injury in PUV. PATIENT SUMMARY: We found that variants of the CDH12 gene increase the risk of kidney injury in patients with extra flaps of tissue in the urethra (posterior urethral valves). This is the first report on this gene in this context. Our study provides interesting new information about the pathways involved and important leads for further research for this condition.

Prognostic Factors on Graft Function in Pediatric Kidney Recipients.

BACKGROUND: Graft survival in pediatric kidney transplant recipients has increased in the last decades. Determining prognostic factors for graft function over time allows the identification of patients at risk for graft loss and could lead to improvement of current guidelines. METHODS: Data were collected among pediatric kidney transplant recipients in a single center during the first 5 years after transplantation. Mixed model analysis was used to indicate possible prognostic factors for the loss of graft function. RESULTS: A total of 100 pediatric kidney transplant recipients were analyzed. Negative prognostics of graft function are higher donor age and higher recipient age, presence of obstructive uropathology, re-transplant, and occurrence of BK viremia. The negative influence on graft function of both donor age and presence of obstructive uropathology increased over time. In this study, the factors that did not influence graft function over time were the number of HLA mismatches, pre-transplant dialysis, intra-abdominal graft placement, ischemia time, occurrence of acute rejection, presence of lower urinary tract dysfunction, occurrence of urinary tract infections, and infections with cytomegalovirus and Epstein-Barr virus. CONCLUSIONS: This study showed that a higher donor age and higher recipient age, presence of obstructive uropathology, a re-transplant, and the occurrence of BK viremia were negative prognostic factors of graft function over time, in the first 5 years after transplant. Graft function was comparable between steroid-sparing regimens (preferable in low-risk patients) and regimens including steroids (for special reasons).

Endo-Urological Techniques for Benign Uretero-Ileal Strictures Have Poor Efficacy and Affect Renal Function.

INTRODUCTION: Uretero-ileal strictures (UES) following urinary diversion are therapeutically challenging. We compared the efficacy, safety and renal outcome following therapeutic endo-urological techniques (EUTs) and open surgical revision of the anastomosis (SRA) for UES. MATERIAL AND METHODS: We retrospectively analysed all EUTs and SRAs performed for UES in 2 hospitals between 1987 and 2015. Restenosis was defined as recurrent radiographically diagnosed hydronephrosis and re-intervention. Renal function (estimated glomerular filtration rate [eGFR]) decrease was correlated with the number of EUTs per patient. RESULTS: Eighty-five UES were treated with 105 EUTs and 31 open revisions. Due to total obstruction, 28 (27%) EUTs were aborted. During a median follow-up of 33 months, restenosis occurred following 53 out of 77 (69%) completed EUTs and 4 out of 31 (13%) SRAs (p < 0.001 on univariable and multivariable analyses). No serious (Clavien ≥3b) EUT-related complications occurred vs. 5 (19%) related to SRA (p < 0.001). The number of finalised EUTs was independently associated with eGFR loss (ß = 12.3 mL/min/1.73 m2 loss per EUT, p = 0.008), with a significant cutoff value of >1 EUTs. SRA did not affect renal function (ß = 6.8 mL/min/1.73 m2 loss, p = 0.276). CONCLUSIONS: Although EUTs are less invasive, they have an inferior efficacy to SRA. Our results suggest that a maximum of one EUT may be attempted without significantly compromising renal function.

Effectiveness of percutaneous tibial nerve stimulation in the treatment of overactive bladder syndrome.

Overactive bladder syndrome (OAB) is a common condition affecting adults and children worldwide, resulting in a substantial economic and psychological burden. Percutaneous tibial nerve stimulation (PTNS) is derived from acupuncture used in Chinese traditional medicine and was first described in the early 1980s. It is a neuromodulation technique used to modulate bladder function and facilitate storage. Being a minimally invasive, easily applicable, but time-consuming treatment, future developments with implantable devices might be the solution for the logistical problems and economic burden associated with PTNS on the long term. This nonsystematic review provides a current overview on PTNS and its effectiveness in the treatment of OAB for both adults and children.

Clinical utility of neurostimulation devices in the treatment of overactive bladder: current perspectives.

OBJECTIVES: This review describes the evidence from established and experimental therapies that use electrical nerve stimulation to treat lower urinary tract dysfunction. METHODS: Clinical studies on established treatments such as percutaneous posterior tibial nerve stimulation (P-PTNS), transcutaneous electrical nerve stimulation (TENS), sacral nerve stimulation (SNS) and sacral anterior root stimulation (SARS) are evaluated. In addition, clinical evidence from experimental therapies such as dorsal genital nerve (DGN) stimulation, pudendal nerve stimulation, magnetic nerve stimulation and ankle implants for tibial nerve stimulation are evaluated. RESULTS: SNS and P-PTNS have been investigated with high-quality studies that have shown proven efficacy for the treatment for overactive bladder (OAB). SARS has proven evidence-based efficacy in spinal cord patients and increases the quality of life. TENS seems inferior to other OAB treatments such as SNS and P-PTNS but is noninvasive and applicable for ambulant therapy. Results from studies on experimental therapies such as pudendal nerve stimulation seem promising but need larger study cohorts to prove efficacy. CONCLUSION: Neurostimulation therapies have proven efficacy for bladder dysfunction in patients who are refractory to other therapies. SIGNIFICANCE: Refinement of neurostimulation therapies is possible. The aim should be to make the treatments less invasive, more durable and more effective for the treatment of lower urinary tract dysfunction.

Anuria in a solitary kidney with Candida bezoars managed conservatively.

UNLABELLED: Renal involvement is regularly encountered in neonates with invasive candidiasis, especially when risk factors like congenital malformations of the renal tract or poor bladder emptying and preterm birth are present. However, complete obstruction of the renal collecting system by fungal balls is rare. Although conservative management has been advocated for partial obstruction, complete obstruction is considered an indication for surgical drainage. We report a patient with anuria and Candida albicans bezoars in a solitary kidney, suggesting post-renal acute kidney injury. The patient was treated with systemic fluconazole and peritoneal dialysis for 4 days. The fungus balls disappeared and renal function recovered. CONCLUSION: Systemic antifungal therapy leads to clearance of obstructing fungus balls, and nephrostomy should be reserved for anuria due to bilateral complete obstruction with severe hydronephrosis. In these cases, temporary dialysis is a potential alternative.