Objective: The aim was to evaluate the efficacy of high-pressure balloon dilatation (HPBD) for primary obstructive megaureter (POM) treatment in infants.

Methods:The authors retrospectively reviewed medical records of 5 infants diagnosed with symptomatic or progressive POM and treated with HPBD between 2015 and 2022 in one hospital, analyzing changes in ureteral and anteroposterior pelvic diameters, Society for Fetal Urology grading, parenchymal thickness, differential renal function, complications, and subsequent surgical needs.

Results: High-pressure balloon dilatation was performed on 5 patients, median age 5 months. No statistically significant changes were detected in ureteral diameter (median 11.0-7.0 mm, P = .125), anteroposterior diameters (median 21.5-18 mm, P = .255), parenchymal thickness (median 5.0-5.0 mm, P = .317), or differential renal function post-procedure. Follow-up was median 34 months. Three patients showed improvement in obstructive renogram findings. Complications were primarily related to guidewire insertion and double-J stent placement. Two patients, both younger than 6 months, required open ureteral reimplantation.

Conclusion: High-pressure balloon dilatation serves as a minimally invasive approach for POM but is not universally effective, with a high complication rate and 40% of infants needing open surgery post HPBD.