Despite the fact that remote shock wave lithotripsy is a non-invasive method of surgical treatment of urolithiasis, the issue of diagnosis and possible reduction of the degree of acute kidney injury, the outcome of which is to varying degrees each session, remains relevant. The article represents a bibliographical sources analysis covering an extensive range of modern biomarkers detected in blood and urine tests used to assess the acute kidney injury of various etiologies, including shock wave lithotripsy. The statistical significance, advantages and disadvantages of the described new indicators are analyzed as well as the possibility of their complex application aiming to rather objective assessment of the degree of damage.

Aim. To evaluate the age dependence of efficacy and safety in high-pressure balloon dilatation (HPBD) for primary obstructive megaureter (POM) in children under 2 years. Materials and methods. From 2020 to 2022, we performed a single-center, unblinded study, with a total of 200 children, treated with HPBD for POM: 117 boys and 83 girls. Study included patients from 1 month to 2 years. The follow-up period was 1 year. Results. In this series the overall treatment effectiveness was 92.5%. In 15 cases treatment was not effective and these children proceeded with ureteral reimplantation. We didn’t achieve positive treatment results in children older than 15 months and our statistical model was not significant for failed cases. Treatment failure we presumed to be due to hard to dilate severe stenosis and extreme length of the stenotic area. Conclusion. In our study we found HPBD of uretero-vesical junction to be safe and effective method for treatment of primary obstructive megaureter in young children. The overall success rate was 92.5%. We recommend considering HPBD as the first line treatment for POM in young children. In failure cases we suggest to perform ureteral reimplantation.

КЛИНИЧЕСКАЯ И ЭКСПЕРИМЕНТАЛЬНАЯ ХИРУРГИЯ■ МАЛОИНВАЗИВНЫЕ ТЕХНОЛОГИИ Цель -определить возможность использования баллонных катетеров, применяемых в кардиохирургии при проведении баллонной дилатации высокого давления (БДВД) для лечения обструкции пузырно-мочеточникового сегмента (ПМС) у детей.Материал и методы.С 2019 по 2021 г. 27 мальчикам и 24 девочкам с диагнозом «первичный обструктивный мегауретер» выполнена БДВД ПМС.Средний возраст на момент оперативного вмешательства -19 мес.Период наблюдения за пациентами составил 1 год.Пациенты при анализе данных были разделены по возрасту на 2 группы: от 1 мес до 1 года, от 1 года до 4 лет.Результаты.Как показали наши исследования, в качестве критериев эффективности лечения можно использовать протяженность стенозированного участка мочеточника, диаметр стеноза и его площадь, определяемые в процессе выполнения БДВД на основании прицельной ретроградной пиелографии.Общая эффективность лечения первичного обструктивного мегауретера с помощью метода БДВД ПМС составила 84%.В 1-й возрастной группе (от 1 мес до 1 года) установлена эффективность 93%, во 2-й (от 1 года до 4 лет) -75%.Положительные результаты лечения получены при протяженности стенозированного участка до 1,8 мм, диаметре стеноза >0,6 мм и площади стеноза <96,6%.При площади стеноза >99% успех от баллонной дилатации не достигнут.Заключение.Использование баллонных катетеров оправдало себя в траслюминарном способе лечения обструктивного мегауретера у детей младшей возрастной группы.Эффективность предложенного нами метода лечения составила 84%.При выполнении БДВД мы также рекомендуем выполнять высокочастотную прицельную пиелографию для оценки характеристик стенозаэто определяет показания к использованию метода БДВД и повышает его результативность.

Introduction. Recently, the prevalence of urolithiasis in pediatric population has been steadily increasing, but up to now there is no any universal technique for treating urolithiasis in children. Among many options for surgical treatment of upper urinary tract urolithiasis, remote lithotripsy occupies one of the leading positions.Purpose. To highlight principles and mechanisms of remote lithotripsy, its indications and contraindications using a systemic review of modern literature for the period of 2001–2021.Material and methods. A systematic review of foreign and domestic literature for the period of 2001–2021 was made. Key words for the search were : urinary stone disease, urolithiasis, remote (shock wave) nephrolithotripsy, fragmentation of stones. 64 full-text articles out of 1339 literature sources are included in the review.Results. On analyzing the obtained results, it has been found out that one session of remote shock wave lithotripsy is effective in more than 90% of cases, if calculus dimensions are less than 20 mm and its density is less than 1200–1500 Hounsfield units. Location of the calculus also plays a role.Conclusion. Remote shock wave lithotripsy is a reasonable option due to a number of facts, the main of which are non-invasive approach and a large percentage of favorable outcomes associated with cleaning the upper urinary tract from stones.

The article presents a modern view on the prognostic factors of spontaneous resolution and effectiveness of treatment of children with vesicoureteral reflux (VUR). The most frequently used predictors of successful treatment of VUR (grades of reflux, distal ureteral diameter ratio to the distance of the lumbar vertebrae, reflux induction phase on mictional cystourthrography), delayed removal of contrast from the upper urinary tract, gender, age, antenatal hydronephrosis). Methodology, statistical significance, advantages, disadvantages of the described prognostic factors are analyzed.

The purpose of the research was to evaluate the efficacy of the high-pressure balloon dilatation (HPBD) of the vesicoureteral segment (VMS) as treatment of primary obstructive megaureter (POM) in pediatric patients aged 1 month to 2 years old and to identify the clear indications for its practical application. Materials and methods of the research: a single-center experimental uncontrolled open study was conducted in 2019 - 2022; 97 children with POM who underwent HPBP of the VMS: 47 boys and 50 girls. The study involved patients aged 1 month till 2 y/o. Patients underwent targeted retrograde pyelography and were assessed for the parameters of the zone of ureteral stenosis before and after the HPBP of the VMS: the length of the stenosis, its diameter and area. The follow-up period for the patients was 1 year. Results: the overall effectiveness of treatment was 92.8% as 7 ineffective cases were reported that required further reimplantation of the ureter. The most statistically significant predictors for the successful treatment were the length of the stenotic area of less than 1.7 mm, its diameter of more than 0.6 mm and the area of stenosis of less than 96.8%. Also, recovery was predicted if the difference in the diameter of the stenosis zone before and after the HPBP of the VMS was 2.4 mm, and the difference in the stenosis area before and after the HPBP of the VMS was above 49.8%. Conclusion: the HPBP of the VMS is an effective treatment for POM in infants. At the same time, the assessment of the obstruction zone during the HPBP is a necessary diagnostic procedure that serves as a reliable method for predicting the success of the treatment. Upon the receipt of parameters that cannot provide high probability of the positive result of treatment the authors suggest the ureter reimplantation.

Predicting the outcome of endoscopic correction of vesicoureteral reflux (VUR) is an urgent problem in pediatric urology because the identification of predictors for the effectiveness of endoscopic treatment of VUR will optimize the strategy for examination and treatment of the disease. The purpose of the research was to evaluate the statistical impact of various predictors on the success of endoscopic correction of VUR; to predict the clinical outcome by creating a mathematical model. Materials and methods used: a single-center experimental uncontrolled study was conducted in Sept. 2017 - Feb. 2022. The results of treatment of 150 pediatric patients (240 renal units) aged from 1 month till 7 years old who underwent endoscopic correction of VUR are presented. The following indicators were evaluated as predictors: gender, age of the disease manifestation, bilateral/unilateral VUR, grade of VUR, ureteral diameter ratio (UDR), cystography initial confirmation of VUR, expansion of the pelvicalyceal system and ureter according to ultrasound, the presence of urinary tract infection. Results: according to the data obtained, when comparing the grade of VUR, cystography initial confirmation of VUR, UDR, expansion of the pelvis and ureter depending on the result of treatment, the statistically significant differences have been found (p<0.001). A prognostic model has been developed to determine the probability of the outcome of endoscopic correction of VUR using the binary logistic regression method. The area under the ROC curve was 0.985±0.007 with 95% CI: 0.967-1.000. The resulting regression model was statistically significant (p<0.001). The sensitivity and specificity of the model were 96.4% and 95.3%, respectively. Conclusion: the results of the research show that UDR and the initial confirmation of VUR have greater predictive power for the success of the endoscopic urethroplasty compared to the grade of VUR alone. The use of the predictors and predictive modeling can help improving the selection of candidates for the endoscopic correction of VUR and developing personalized treatment tactics.

Vesicoureteral reflux (VUR) is one of the most frequent diseases in pediatric urology studied since the 19th century. It has an increased risk of infection of the urinary tract, sclerosis of the renal parenchyma and development of reflux-nephropathy with an outcome in renal failure. Several treatment options have been developed for patients with VUR. For 50 years, open ureteral reimplantation has been considered the «gold standard» of treatment, but over the past 20 years there has been a shift towards less invasive methods, primarily endoscopic administration of bulking agents. In order to increase the effectiveness of endoscopic treatment, several basic recommendations for the operation have been identified and many volume-forming drugs have been developed. The most important is the correct choice of one of the three main methods of drug administration and the hydrodilation of the ureteral orifice during injection. Performing of endoscopic correction in compliance with all the rules and the use of the latest generation of bulking agents ensure the frequency of elimination of VUR up to 90% after the first injection.

Urinary tract infections are the second most common infections in children with spreading of antimicrobial resistance among uropathogens currently poses a high epidemiological threat.Purpose. Analysis of species prevalence and the presence of genetic determinants of antibiotic resistance.Materials and methods. In the study 215 midstream urine samples were retrospectively analyzed. Samples were obtained during 2017 and 2019 from patients aged 4 weeks to 17 years at the National Medical Research Center for Children's Health Federal State Autonomous Institution of the Ministry of Health of the Russian Federation.Results. Species of pathogen were identified in 93 samples, while the bacterial composition of other samples was classified as «intestinal flora» (n = 17), «coccus flora» (n = 16) or «mixed flora» (n = 89). The most common types of uropathogens in monopathogenic infections in 2017 and 2019 were Escherichia coli (37.5% and 29.2%, respectively). Among infections caused by multiple pathogens, the most common etiological agents were Pseudomonas aeruginosa and Staphylococcus spp. Among all studied samples, 31.9% contained CTX-M-like genes, 5% VIM genes, 1.8% NDM genes, and 3.0% — OXA-48-like genes, and 5.6% of samples contained two and more genetic determinants associated with resistance, with the most prevalent gene combination being the combination of CTX-M- and OXA-48-like genes. In 69 samples with identified species of uropathogens, resistance profile to antimicrobial, determined by microbiological methods, correlated with detected resistance genetic determinants.Conclusion. Authors suggest that introduction of testing for the presence of genes associated with antibacterial resistance to general clinical practice would not only provide an opportunity to conduct epidemiological monitoring of the genetic determinants of antibiotic resistance, but also provide an opportunity to select the correct timely treatment of childhood bacteriuria caused by antibiotic-resistant infectious agents.

Introduction. The endoscopic correction of vesicoureteral reflux in children has become a basic treatment technique. Its effectiveness in the low-grade reflux is high. High-grade refluxes are an indication for antireflux reconstructive plastic surgery. The article analyzes outomes of endoscopic treatment of patients with high-grade retrograde urine reflux. Material and methods. A total number of 307 patients (409 ureters) with IV-V grade of vesicoureteral reflux were treated. 156 girls and 151 boys, aged 4 months - 12 years, had the endoscopic correction with Dextranomer and Copolymer of Polyacrylic Polyvinyl Alcohol (PPC). The renal parenchyma damage was assessed with DMSA scan; urinary tract infection - with clinical and laboratory findings (febrile temperature and bacteriuria). Outcomes of treatment were evaluated with micurating cystography performed six months later. It revealed either no reflux or its lower grade - grade one. Average follow-up period was 5. 5 years. Results. The effectiveness of endoscopic correction of vesicoureteral reflux after the first injection was 68.7%. The second injection was effective in 48.9%. Febrile urinary tract infection after the treatment went down up to 6.2%. Marked bacteriuria remained high - 55.3%. Renal parenchyma structural and functional damage was noted in 38.9% of older children; mild and moderate degrees of damage prevailed (45.6% and 40.8%, respectively). Conclusion. The endoscopic correction of high-grade vesicoureteral reflux is recommended as the first line treatment for retrograde urine reflux. This technique is highly effective and minimally invasive.

Actuality. To date, there are few publications focused on pneumovesicoscopic ureteral reimplantation in young children. The article is devoted to surgical interventions in this age group. Material and methods. Surgical interventions on small volume bladder have significant technical difficulties. The authors assessed potentials for performing pneumovesicoscopic ureteral reimplantation by the Cohen technique in 14 children under 2 with various obstructive uropathies. Results. In all children, surgical interventions were performed according to preoperative plans. There were no conversions to an open procedure. As it has been found out, patient’s age and bladder volume were not limiting factors for this type of intervention. Conclusion. The pneumovesicoscopic ureteral reimplantation in young children is a hi-tech procedure which requires a unique equipment and a highly qualified surgical team. To reduce the procedure duration, further experience and more information are needed.

Introduction. The primary obstructive megaureter in children of the first months and years of life does not require surgical treatment in most cases. But if the kidney function deteriorates and an obstructive pattern of urodynamics of the upper urinary tract is formed, then surgical intervention is required. Reimplantation is usually applied, if a patient is older than one year. In infants, minimally invasive endoscopic methods are more applicable. Nevertheless, results of treatment are ambiguous and not satisfactory in some cases. Purpose. To assess and to compare levels of efficiency of endoscopic stenting, high pressure balloon dilatation (HPBD) and reimplantation. To propose an algorithm for the selection and sequential application of the discussed surgical procedures depending on patient’s age and on the degree of renal function damage. Material and methods. 224 children were taken into the study. They were divided into three groups. Stenting, HPBD or reimplantation were used as a treatment modality in each group, respectively. Effectiveness criteria were: improvement of renal function by the nephroscintigraphy, reduction in size of the ureter and excretory system as well as the increase in parenchyma volume by ultrasound. Non-parametric statistics - Wilcoxon test, chi-square test, Spearman correlation. The level of significance is 0.05. Results. Stenting is effective in 48% of children of the first year of life, but in older patients its effectiveness significantly decreases (about 20%). A high level of HPBD efficiency (about 70%) was achieved in subgroups of patients of the first three years of life; however, it was significantly lower in patients of older age. Reimplantation is maximally effective (about 98%) in subgroups of patients older than one, but not effective (33%) in the subgroup of patients of the first year of life. Conclusion. Endoscopic stenting is indicated for patients of the first year of life with minimal disorders in their urodynamics and renal function, while it is not an option for older patients. HPBD is more effective in patients of the first two years of life with moderate urodynamic disorders. Reimplantation with the effectiveness level about 100% is a method of choice in patients older than one year and cannot be recommended in infancy.

Ectopic of the ureter into the cervix is a rare case in the clinical practice of pediatric urologists around the world. This paper presents an observation of congenital urinary incontinence in a 13-year-old girl who underwent an annual examination in a hospital at the place of residence.

The first method of the examination for suspected urolithiasis in children is ultrasound (US) diagnosis, allowing with the high accuracy to identify concrements of 5 mm or more, as hyperechoic signals in organs of the urinary system. However, the diagnostic accuracy is reduced in the presence of smaller stones, it can also be a lot of small structures, not associated with calculi. There are described ultrasound signs of the differentiation between the stones and not associated with them structures in the kidneys in children with various forms of pathology. A common feature of these structures is the absence of distal «shadow» in the study, even in examination with the help of high-frequency transducers. There are also shown some artifacts of both vascular and non-vascular origin which in the case of a small size resemble concrements. Therefore it is possible to use color Doppler. The authors emphasize the importance of other research methods, indicating that the data of the ultrasound examination results are inconclusive. An alternative method is computed tomography of kidneys.