Kidney Anomalies Research Articles

Using automated machine learning to detect kidney anomalies.

483 Background: Artificial Intelligence (AI) in Urology has been used for many conditions including benign prostatic hyperplasia (BPH), urological oncology, and kidney transplant. Many computer models use algorithms that may be intricate for urologists to implement, but automated machine learning (AML) can be used to create simple models. Here we expand the use of AI and AML in image detection of kidney tumors, stones, and unremarkable kidney from computed tomography (CT) using Google Vertex AI, a machine learning platform that allows for the building, training, and deployment of models. Methods: Google Vertex AI machine learning system was trained to perform image detection. CT Kidney images were taken from publicly available data from Kaggle, an online database and machine learning platform. Images are from multiple hospitals in Dhaka, Bangladesh. 300 CT Kidney Images were uploaded on Google Vertex AI: 100 tumors, 100 stone, and 100 normal. 240 images were used to train the model, 30 for validation, and a final 30 images for assessing the accuracy of predictions after the training phase. To comprehensively evaluate our model, CT kidney images from the Cedars Sinai Medical Center were employed for further testing. All training images lacked annotations and were solely classified as normal, stone, or tumor. Results: True positivity rate for image detection during model training was 100% for tumors, stones, and normal CTs. We further tested accuracy using Cedars Sinai patient images, using 10 tumors, 10 stones, and 5 normal. The accuracy of the AI prediction was 80%, 70%, and 100%, respectively. Conclusions: Artificial Intelligence can be useful in interpreting urological imaging even in a minimally trained system. A model such as ours may allow for rapid identification and labeling of renal masses, kidney stones, and normal studies with moderate fidelity. Further training of this model may increase accuracy.

The expanded spectrum of human disease associated with GREB1L likely includes complex congenital heart disease.

GREB1L has been linked prenatally to Potter's sequence, as well as less severe anomalies of the kidney, uterus, inner ear, and heart. The full phenotypic spectrum is unknown. The purpose of this study was to characterize known and novel pre- and postnatal phenotypes associated with GREB1L. We solicited cases from the Fetal Sequencing Consortium, screened a population-based genomic database, and conducted a comprehensive literature search to identify disease cases associated with GREB1L. We present a detailed phenotypic spectrum and molecular changes. One hundred twenty-seven individuals with 51 unique pathogenic or likely pathogenic GREB1L variants were identified. 24 (47%) variants were associated with isolated kidney anomalies, 19 (37%) with anomalies of multiple systems, including one case of hypoplastic left heart syndrome, five (10%) with isolated sensorineural hearing loss, two (4%) with isolated uterine agenesis; and one (2%) with isolated tetralogy of Fallot. GREB1L may cause complex congenital heart disease (CHD) in humans. Clinicians should consider GREB1L testing in the setting of CHD, and cardiac screening in the setting of GREB1L variants.

Development of a tool for predicting HNF1B mutations in children and young adults with congenital anomalies of the kidneys and urinary tract

BackgroundWe aimed to develop a tool for predicting HNF1B mutations in children with congenital abnormalities of the kidneys and urinary tract (CAKUT).MethodsThe clinical and laboratory data from 234 children and young adults with known HNF1B mutation status were collected and analyzed retrospectively. All subjects were randomly divided into a training (70%) and a validation set (30%). A random forest model was constructed to predict HNF1B mutations. The recursive feature elimination algorithm was used for feature selection for the model, and receiver operating characteristic curve statistics was used to verify its predictive effect.ResultsA total of 213 patients were analyzed, including HNF1B-positive (mut + , n = 109) and HNF1B-negative (mut − , n = 104) subjects. The majority of patients had mild chronic kidney disease. Kidney phenotype was similar between groups, but bilateral kidney anomalies were more frequent in the mut + group. Hypomagnesemia and hypermagnesuria were the most common abnormalities in mut + patients and were highly selective of HNF1B. Hypomagnesemia based on age-appropriate norms had a better discriminatory value than the age-independent cutoff of 0.7 mmol/l. Pancreatic anomalies were almost exclusively found in mut + patients. No subjects had hypokalemia; the mean serum potassium level was lower in the HNF1B cohort. The abovementioned, discriminative parameters were selected for the model, which showed a good performance (area under the curve: 0.85; sensitivity of 93.67%, specificity of 73.57%). A corresponding calculator was developed for use and validation.ConclusionsThis study developed a simple tool for predicting HNF1B mutations in children and young adults with CAKUT.Graphical abstract A higher resolution version of the Graphical abstract is available as Supplementary information

Antenatal hydronephrosis – surrogate marker of congenital kidney and urinary tract anomalies in children Suggested citation for this article: Picioreanu I, Picioreanu DM. Antenatal hydronephrosis – surrogate marker of congenital kidney and urinary tract anomalies in children. Medic.ro. 2024;157(1):12-20.

Antenatal hydronephrosis – surrogate marker of congenital kidney and urinary tract anomalies in children Suggested citation for this article: Picioreanu I, Picioreanu DM. Antenatal hydronephrosis – surrogate marker of congenital kidney and urinary tract anomalies in children. Medic.ro. 2024;157(1):12-20.

Acute kidney injury in birth asphyxiated patients: A cross sectional study at Bahawal Victoria Hospital.

The presence of perinatal asphyxia and its severity appear to correlate with increasing incidence of Acute kidney injury (AKI). The objective of this study is to determine the frequency of AKI and its outcome in birth asphyxia. This cross-sectional study was carried out in the Department of Pediatric Medicine from March 2019 to September 2019. A total of 111 newborns with birth asphyxia of gestational age 37-41 weeks were included. Neonates born to mothers having hypertension and diabetes mellitus, patients with congenital kidney anomalies like polycystic kidney disease and renal agenesis, and mothers taking nephrotoxic drugs or any other known cause of AKI like hypovolemic shock were excluded. Urine output (UOP) and final outcome of the patient were also noted. AKI was noted. The mean gestational age was 38.29 ± 1.07 weeks. The mean weight of neonates was 3.08 ± 0.31 kg. The frequency of AKI in birth asphyxia was 20 (18.02%) neonates. Complete recovery in AKI patients was seen in 07 (35.0%) and death in 13 (65.0%) patients. This study has shown that the frequency of AKI in birth asphyxia was found in 18.02% neonates with complete recovery seen in 35.0% and death in 65.0% patients.

Spectrum of pathogenic variants and high prevalence of pathogenic BBS7 variants in Russian patients with Bardet-Biedl syndrome.

Bardet-Biedl syndrome is a rare condition characterized by obesity, retinitis pigmentosa, polydactyly, development delay, and structural kidney anomalies. This syndrome has an autosomal recessive type of inheritance. For the first time, molecular genetic testing has been provided for a large cohort of Russian patients with Bardet-Biedl syndrome. Genetic testing was provided to 61 unrelated patients using an MPS panel that includes coding regions and intronic areas of all genes (n = 21) currently associated with Bardet-Biedl syndrome. The diagnosis was confirmed for 41% of the patients (n = 25). Disease-causing variants were observed in BBS1, BBS4, BBS7, TTC8, BBS9, BBS10, BBS12, and MKKS genes. In most cases, pathogenic and likely pathogenic variants were localized in BBS1, BBS10, and BBS7 genes; recurrent variants were also observed in these genes. The frequency of pathogenic and likely pathogenic variants in the BBS1 and BBS10 genes among Russian patients matches the research data in other countries. The frequency of pathogenic variants in the BBS7 gene is about 1.5%-2% of patients with Bardet-Biedl syndrome, while in the cohort of Russian patients, the fraction is 24%. In addition, the recurrent pathogenic variant c.1967_1968delinsC was detected in the BBS7 gene. The higher frequency of this variant in the Russian population, as well as the lack of association of this pathogenic variant with Bardet-Biedl syndrome in other populations, suggests that the variant c.1967_1968delinsC in the BBS7 gene is major and has a founder effect in the Russian population. Results provided in this article show the significant role of pathogenic variants in the BBS7 gene for patients with Bardet-Biedl syndrome in the Russian population.

A Rare Cause of Hypotonia: 49,XXXXX (Pentasomy X)

Pentasomy X syndrome is a very rare sex chromosome numerical anomaly of unknown frequency. The karyotype consists of 49,XXXXX. Musculoskeletal, craniofacial, cardiac, and kidney anomalies accompany psychomotor developmental delays. This report describes, a 16-month-old girl who presented to the pediatric neurology outpatient clinic with complaints of joint laxity and inability to hold her head upright from the age of 3-4 months. The patient exhibited dysmorphic facial features and hand-foot deformities. Genetic consultation was requested, and cytogenetic examination revealed a 49,XXXXX chromosomal anomaly. The most prominent clinical feature of 49,XXXXX patients with pentasomy is severe hypotonia. This article emphasizes the importance of cytogenetic analysis in the evaluation of hypotonicity.

Congenital anomalies of kidney and urinary tract (CAKUT) and associated extra-renal anomalies in fetal autopsies.

According to studies, 1% of all pregnancies have an abnormality, with 20-30% of those affecting the genitourinary system. Congenital abnormalities of the kidney and urinary tract (CAKUT) is one of the primary causes of perinatal and neonatal mortality in children. Many extra-renal congenital illnesses accompany these defects, affecting the patient's prognosis. This study aims to determine the subtypes, frequency, and extra-renal defects associated with congenital anomalies of the urinary system, which is the major cause of mortality in fetal and infant autopsies throughout the perinatal and neonatal eras. We believe that our study will contribute to the literature because few autopsy investigations can give this data. The study included 110 fetal autopsies between January 1997 and May 2019. 10% were newborns under the age of one year, and 90% were fetus autopsies. Males accounted for 67.3% of the cases, while females accounted for 35 (31.8%) (the gender of one case could not be determined). Renal dysplasia was the most frequent CAKUT, with a rate of 22.73%, followed by renal agenesis, with a rate of 20.0%. Eighty-four cases (76.3%) showed disease in at least one other organ system. Musculoskeletal system (MSS) abnormalities were the most common associated system anomaly, with one or more MSS anomalies (34.55%) detected in 38 cases. Finally, we want to underline that CAKUT and its associated anomalies are not uncommon. Prenatal imaging, genetic investigation, and/or postmortem examination should all be used to screen for CAKUT. This information is helpful for the mother's future pregnancy management and parental genetic counseling.

Hospitalizations after Renal Transplantation in Children: Risk Factors, Causes, and Outcomes

Introduction: The aims of this study were to evaluate the frequency and causes of hospitalizations in the posttransplant period of children, investigate the risk factors, and evaluate the relationship between hospitalizations and renal prognosis in the long term. Methods: We retrospectively reviewed the files of pediatric renal transplant patients, followed at least 6 months after kidney transplantation, in our center. Clinical information including age at transplantation, gender, primary disease, donor type, immuno-suppressive medication, hospitalization dates, and indications (infections and non-infectious) during follow-up period and graft outcomes was recorded. Results: A total of 74 children (46 males) were followed up for a median of 54 months. Among them, 69 patients (93.2%) were hospitalized 446 times. The most common cause of hospitalizations was infections (314 times, 70%). Urinary tract infections were the most important cause followed by upper respiratory tract infections. Forty (54%) patients were hospitalized 132 times (29.5%) for non-infectious reasons. The most common non-infectious reason was nonspecific graft dysfunction (19 patients, 30 times), followed by rejection (17 patients, 27 times). Younger age, use of induction therapy, and having congenital anomalies of kidney and urinary tract (CAKUT) were found to be risk factors for increased hospitalization rates (p < 0.05). The number of hospitalizations was found to be negatively affecting the final glomerular filtration rate of transplant recipients (p: 0.04, r: –0.023). Conclusion: Patients with CAKUT, who received induction therapy, and small children were hospitalized more frequently after transplantation. Strategies to prevent hospitalizations will achieve a better graft prognosis.

Hypertension in children with congenital anomalies of the kidney and urinary tract.

Congenital anomalies of the kidney and urinary tract (CAKUT) are the most common cause of childhood chronic kidney disease (CKD). We hypothesized that hypertension varies across CAKUT categories and increases the risk of CKD. This was a retrospective cohort study and included cases with a multicystic dysplastic kidney (MCDK, n = 81), unilateral kidney agenesis (UKA, n = 47), kidney hypoplasia (KH, n = 130), and posterior urethral valves (PUV, n = 75). Hypertension was defined as systolic or diastolic blood pressure ≥ 95th percentile for age, sex and height, and CKD as an estimated glomerular filtration rate < 60ml/min/1.73 m2, both at 2 consecutive clinic visits at least 3months apart. Sixty-two (19%) out of 333 cases developed hypertension, with significant difference according to CAKUT type. Patients with smaller kidney size (7.7 vs. 8.3, p = 0.045), kidney anomalies in addition to the primary diagnosis (aCAKUT) (53 vs. 38%, p = 0.03), proteinuria (46 vs. 12%, p < 0.001), and CKD (51 vs. 23%, p < 0.001) were more likely to develop hypertension. When adjusted for kidney size, the diagnoses of PUV (OR 10.9, 95%CI 3.0, 40.5), UKA (OR 6.4, 95%CI 1.6, 24.9) and KH (OR 4.2, 95%CI 1.1, 16.1), and aCAKUT (OR 2.1, 95%CI 1.2, 3.9) were independent risk factors for hypertension. Hypertension increased the risk of developing CKD by twofold (HR 1.9, 95%CI 1.19, 2.94). Hypertension is common in children with CAKUT and increases the risk of CKD. These findings will aid in the development of a standardized clinical pathway for the care of hypertensive children with CAKUT.

A Pictorial Presentation of Three Kidney Anomalies in Computed Tomography

A Pictorial Presentation of Three Kidney Anomalies in Computed Tomography

Evaluating the requirement of ultrasonography for children with their first urinary tract infection

Management of urinary tract infection (UTI) in children remains important. It may be the first sign for a possible underlying congenital abnormalities for the kidney and urinary tract (CAKUT). This study examined whether performing renal and bladder ultrasonography (RBUS) only for children who have a pathogen other than E. coli during their first urinary tract infection (UTI), or who experience UTI recurrence, would result in more missed diagnoses of kidney anomalies. Patients aged between 2 months and 2 years who were seen in a tertiary pediatric hospital during a 2-year period and diagnosed with UTI were included. RBUS and voiding cystourethrography (VCUG) were performed according to American Academy of Pediatrics (AAP) guidelines. Afterwards, we looked back and evaluated how often we found kidney problems when we only did a RBUS on patients who had an atypical cause of their first UTI or who had multiple UTIs. One hundred and seventy-eight patients who were followed up with UTI were included in this study. The isolated pathogen was E. coli in 104 cases (58.4%) and atypical in 74 cases (41.6%). VCUG was conducted on 40 patients, and vesicoureteral reflux (VUR) was discovered in 16 cases and ureteropelvic junction obstruction (UPJO) was discovered in 1 case. A different diagnostic approach that required the presence of an atypical pathogen at the first UTI or a fUTI recurrence to perform the RBUS would have missed just two severe kidney anomalies. It was observed that there could be a decrease of 40.4% in RBUS and at least 20% in VCUG. A diagnostic approach that necessitates the presence of an abnormal pathogen during the initial UTI or a second UTI episode for the RBUS to be carried out would lead to fewer negative ultrasounds with minimal risk of overlooking kidney anomalies.

Ukraine: Chronic Kidney Disease in children and adolescents: retrospective and priorities

The present study aimed to assess the prevalence and structure of chronic kidney disease (CKD) in children and adolescents to determine the priorities for the development of pediatric nephrology in Ukraine.&#x0D; Methods. Individuals who were born in Ukraine after 1994 and had CKD diagnosed before the age of 18 were investigated. The number of CKD cases was estimated per 100,000 newborns depending on the year of birth, divided into time intervals: 1995-2004 and 2005-2022 years of birth. Both groups were stratified with the generalization of the etiological component. The patients on Kidney Replacement Therapy (KRT) were separated into special clinical group, and the etiological and age spectrum analysis of KRT initiation was performed depends of the year of birth. In addition, cross-sectional analysis of the etiological structure of KRT incidence and prevalence in years 2019 and 2021 was conducted.&#x0D; Results. The prevalence of CKD in children and adolescents in Ukraine increased over a long period up to year 2022 (average cases per 100,000 births: 43.5 in years 1995-2004, 37.0 in years 2005-2022:) with an amplification of early stages (CKD1-4: year 2010 - 81.4%, year 2022 - 92.0%) and KRT decrease, respectively (average cases per 100,000 births: 6.5 and 3.3 in the analyzed time intervals). The individuals with primary urological pathology made up a third or more among CKD patients (depending on the year of birth). The etiological and age spectrum differences of KRT were determined in the analyzed time intervals. Depending on the underlying cause of CKD, the age of KRT initiation in born before year 2005 varied from 9 to 16 years, in the following period - from 1 to 9 years.&#x0D; The differences from the ESPN Registry were identified in cross-sectional etiological spectrum of CKD with KRT initiation in year 2019 (age up to 15 years old): the higher proportion of patients after Acute Kidney Injury/AKI (16.7%) or with glomerulonephritis/GN (30.0%), and the smaller one of congenital anomalies of kidney and urinary tract/CAKUT (26.6%). The distribution of KRT causes in Ukraine under the age of 18 did not change in years 2019 and 2021 (including polycystic kidney disease/PKD 12.1-11.2%, GN 15.0-16.5%, AKI 12.1-13.1%, CAKUT 32.4-31.0%, respectively), but only for CAKUT and PKD was approximated to ISPN Global Registry data.&#x0D; Conclusions. The revealed qualitative changes in the etiological and age structure of morbidity over a long period in Ukraine indicate the CKD pathomorphosis and require updating the clinical managment of patients depends of the economic and organizational potential of the country, the challenges of martial law and the difficulties of the next recovery period.

Congenital anomalies of the kidney and urinary tract: antenatal diagnosis, management and counselling of families.

Congenital anomalies of the kidney and urinary tract are collectively one of the most commonly diagnosed antenatal conditions. Clinicians have several tools available to diagnose anomalies, including imaging, biomarkers, family history and genetic studies. In certain cases, antenatal interventions such as vesico-amniotic shunting may be considered to improve postnatal outcomes.Congenital kidney anomalies detected antenatally can vary in clinical significance from almost no impact postnatally to significant morbidity and perinatal mortality. Prognosis broadly depends on kidney size, structure and amount of amniotic fluid, alongside genetics and family history, and progression on subsequent scans. It is important to counsel parents appropriately using a parent-focused and personalised approach. The use of a multidisciplinary team should always be considered.

Combined Laparoscopic Pyelolithotomy with RIRS in a Patient with Horseshoe Kidney Anomaly and Kidney Stone: A Case Report

Horseshoe Kidney is the most prevalent congenital kidney fusion anomaly, affecting 0.25 percent of the general population and occurring in 1 in 400 to 1600 births. Approximately forty percent of patients develop kidney stones due to anomalies. In our case, we aimed to perform combined laparoscopic pyelolithotomy with RIRS instead of PCNL in a patient with horseshoe anomaly. This procedure enabled us to detect the location of the mobile stone with RIRS and then successfully extract it with laparoscopic pyelolithotomy. Laparoscopic pyelolithotomy combined with RIRS is a reasonable additional treatment option for complicated stone surgery due to horseshoe kidney anomalies.

Pyeloplasty in Children with Ureteropelvic Junction Obstruction and Associated Kidney Anomalies: Can a Robotic Approach Make Surgery Easier?

Robot-assisted pyeloplasty is widely used in pediatric surgery because of its well-known advantages over open or laparoscopic surgery. The aim is to explore our experience and evaluate the achievements we have made. We evaluated patients undergoing robotic pyeloplasty from January 2016 to November 2021, including those who presented with a ureteropelvic junction obstruction associated with other anomalies of the kidney. The parameters examined were: age, weight, associated renal malformations, conversion rate, operative time, and intra- and postoperative complications. Of 39 patients, 7 (20%) were included, of whom 5 (71%) were male and 2 (29%) were female. The mean age at surgery was 84 months (range 36-180 months), and the mean weight at surgery was 24.4 kg (range 11-40 kg). In five (71%) patients the ureteropelvic junction obstruction (UPJO) was left-sided and in two (29%) it was right-sided. In four (57%) cases, UPJO was associated with a horseshoe kidney, right-sided in one (25%) patient, and left-sided in the other three (75%). A 180° rotation of the kidney was present in one (14%) patient. Nephrolithiasis was present in two (29%) patients. The mean operative time was 160 min (range 140-240 min). The average bladder catheter dwell time was 1 day (range 2-3 days), while the average abdominal drainage dwell time was 2 days (range 2-4 days). The mean hospitalization time was 4 days (range 3-9 days). On average, after 45 days (range 30-65) the JJ ureteral stent was removed cystoscopically. No intraoperative complications were reported, while one case of persistent macrohematuria with anemia requiring blood transfusion occurred postoperatively. Ureteropelvic junction obstruction might be associated with other congenital urinary tract anomalies such as a duplicated collecting system, horseshoe kidney, or pelvic kidney. These kinds of malformations can complicate surgery and require more attention and accuracy from the surgeon. Our experience shows that, with regards to the robotic learning curve required for pyeloplasty, the treatment of the ureteropelvic junction in these situations does not present insurmountable difficulties nor is burdened by complications. The application of robot-assisted surgery in pediatric urology makes difficult pyeloplasties easier.

Integrated analysis of copy number variation-associated lncRNAs identifies candidates contributing to the etiologies of congenital kidney anomalies

Congenital anomalies of the kidney and urinary tract (CAKUT) are disorders resulting from defects in the development of the kidneys and their outflow tract. Copy number variations (CNVs) have been identified as important genetic variations leading to CAKUT, whereas most CAKUT-associated CNVs cannot be attributed to a specific pathogenic gene. Here we construct coexpression networks involving long noncoding RNAs (lncRNAs) within these CNVs (CNV-lncRNAs) using human kidney developmental transcriptomic data. The results show that CNV-lncRNAs encompassed in recurrent CAKUT associated CNVs have highly correlated expression with CAKUT genes in the developing kidneys. The regulatory effects of two hub CNV-lncRNAs (HSALNG0134318 in 22q11.2 and HSALNG0115943 in 17q12) in the module most significantly enriched in known CAKUT genes (CAKUT_sig1, P = 1.150 × 10−6) are validated experimentally. Our results indicate that the reduction of CNV-lncRNAs can downregulate CAKUT genes as predicted by our computational analyses. Furthermore, knockdown of HSALNG0134318 would downregulate HSALNG0115943 and affect kidney development related pathways. The results also indicate that the CAKUT_sig1 module has function significance involving multi-organ development. Overall, our findings suggest that CNV-lncRNAs play roles in regulating CAKUT genes, and the etiologies of CAKUT-associated CNVs should take account of effects on the noncoding genome.

Incremental hemodialysis in pediatric patients.

Incremental hemodialysis follows the concept of adjusting dialysis dose according to residual kidney function. Data on incremental hemodialysis in pediatric patients is lacking. We conducted a retrospective analysis of children initiating hemodialysis between January 2015 and July 2020 in a single tertiary center, comparing the characteristics and outcomes of those who commenced with incremental hemodialysis vs with conventional thrice-weekly regimen. Data onforty patients, 15 (37.5%) on incremental hemodialysis and 25 (63%) on thrice-weekly hemodialysis were analyzed. No differences in age, estimated glomerular filtration rate and metabolic parameters were noted between groups at baseline, but there were more males (73 vs 40%, p = 0.04), more patients with congenital anomalies of kidney and urinary tract (60 vs 20%, p = 0.01), higher urine output (2.5 ± 1 vs 1 ± 0.8ml/kg/h, p < 0.001), lower use of antihypertensive medications (20 vs 72%, p = 0.002) and lower prevalence of left ventricular hypertrophy (6.7 vs 32%, p = 0.003) in the incremental hemodialysis group vs thrice-weekly hemodialysis. During follow up, 5 (33%) incremental hemodialysis patients were transplanted, 1 (7%) remained on incremental hemodialysis at 24months, and 9 (60%) transitioned to thrice-weekly hemodialysis at a median (IQR) time of 8.7 (4.2, 11.8) months. At last follow up, fewer patients who initiated incremental hemodialysis had left ventricular hypertrophy (0 vs 32%, p = 0.016) and urine output < 100ml/24h (20 vs 60%, p = 0.02) compared to thrice-weekly hemodialysis, with no significant differences in metabolic or growth parameters. Incremental hemodialysis is a viable option for initiating dialysis in selected pediatric patients, that may help improve patients' quality of life and reduce dialysis burden without compromising clinical outcome.

Prevalence of Enterococcal Urinary Tract Infections With Positive Nitrites in Urinalysis in Pediatric Patients With High-Risk for Enterococcal Infections.

Enterococcus is a relatively uncommon pathogen that causes urinary tract infections (UTIs) in healthy children. Most enterococcal infections occur in patients with risk factors such as anatomical or functional urinary tract anomalies, also known as CAKUT (congenital anomalies of kidney and urinary tract). Children who are suspected of having UTIs and who have certain risk factors are often treated specifically for enterococcal infection as part of their empiric regimen. Our primary objective was to determine the prevalence of enterococcal UTIs among high-risk children, and specifically among those with positive nitrite tests, with the goal of avoiding treatment with specific anti-enterococcal agents. This retrospective study included all the episodes of UTI treated at a tertiary pediatric center during 2010 to 2018. The data collected from medical records included nephrological and urological risk factors, nitrite status, and isolated pathogens. Of 931 episodes of UTI, 467 (50%) were considered high-risk. In all, 24 of the latter had Enterococcus as a single pathogen; 23 (96%) of these occurred in patients with negative nitrites in the first urine dipstick taken. The sole patient with high-risk factors, a positive nitrite test and coexisting enterococcal UTI had a history of previous enterococcal UTIs. In pediatric patients with nephrological and urological risk factors, who have positive nitrites in urinalysis, the risk for enterococcal UTI appears substantially low. Therefore, in this context, specific anti-enterococcal empirical antibiotic therapy may be unnecessary.

#4923 ARTERIOVENOUS FISTULAS AS HEMODIALYSIS ACCESS IN A PEDIATRIC POPULATION – IS YOUNGER AGE A REASON TO MAINTAIN CENTRAL VENOUS CATHETER?

Abstract Background and Aims In the pediatric population, transplantation remains the first-line therapy in patients with end-stage renal disease (ESRD). However, it is not always possible, increasing the need for other kidney replacement therapy (KRT) modalities, and hemodialysis (HD) has been growing as a modality choice in recent years. To provide quality HD treatment, efficient vascular access is mandatory, and the arteriovenous fistula (AVF) is advocated as the best long-term access option. However, its creation is technically challenging, and its development and maintenance are some of the most difficult elements in the pediatric population. In this study, we describe our experience in the utilization of AVFs in children and adolescents on HD. Method We conducted a retrospective study including all the AVFs performed in our center on underage patients between January 2006 and December 2022. We reviewed the medical records, collected data on demographic variables, AVF characteristics, blood test results, and clinical outcomes. Statistical analysis was performed using SPSS software. Results Forty-three AVFs were performed in 32 pediatric patients. The median age at first AVF construction was 13.5 years (min 4.8; max 17.9). The most frequent etiology of ESRD was congenital anomalies of kidney and urinary tract (n = 20, 62.5%) and most patients (n = 24, 75.0%) were already receiving KRT. Median follow-up time was 16.4 months (min 1; max 98.4) and, at the end of the follow-up period, most patients (n = 22, 68.8%) were transplanted. The mortality rate was 6.3% (n = 2). In what concerns to the location of the AVF, radiocephalic was the first choice in 46.9% of the cases (n = 15), accounting for 34.9% of the total AVFs. Brachiocephalic location was used in 34.4% (n = 11) of first fistulas and 6 subsequent accesses, accounting for 39.5% of the total AVFs. The brachiobasilic location was chosen in 18.8% (n = 6) of the first AVFs and 25.6% of the total AVFs. Primary AVF failure occurred in 26.6% (n = 11) cases and, in 4 of these (36.4%), it was possible to successfully use the same location for a second AVF. We observed no statistical association between primary AVF failure dysfunction and gender, age at the construction of the first fistula, AVF location, or dialysis vintage. Platelet-lymphocyte (PLR) and neutrophil-lymphocyte (NLR) ratios also did not differ between groups. Primary and secondary patency rates at one year were, respectively, 62.5% and 93.8%. With respect to total AVF complications, we observed: thrombosis (27.9%), stenosis (18.6%), distal ischemia induced by vascular access (4.7%), and high flow/aneurismatic dilations (18.6%). The presence of complications was statistically related to age (p = 0.046), with more events in older patients at the time of AVF construction. There was no statistical difference between complications’ occurrence and AVF type, sex, gender, PLR, and NLR. Conclusion The utilization of AVF for HD has been growingly recognized as a safe and efficient alternative for the performance of KRT in pediatric patients. Although larger studies are needed, we demonstrate positive results in its usage in a pediatric population, with high primary and secondary patency rates. These outcomes were independent of the AVF location. We also advocate AVF usage in younger patients, as complications were associated with older age. PLR and NLR, which are emerging biomarkers for systemic inflammation, were not associated with AVF dysfunction, aligning with the results of other studies in pediatrics.