EFFICACY OF HIGH-PRESSURE BALLOON DILATATION AS TREATMENT OF PRIMARY OBSTRUCTIVE MEGAURETER IN INFANTS

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.