Management of ureteropelvic junction obstruction with high-pressure balloon dilatation: long-term outcome in 50 children under 18 months of age.

Objective: To analyze the usefulness of dilatation in the treatment of ureteropelvic junction obstruction (UPJ) in children <18 months of age, including newborns and infants.

Methods: Patients (n = 50; <18 months of age) were diagnosed using abdominal ultrasound, cystogram, and diuretic renography. Treatment was with endourologic retrograde balloon dilatation under fluoroscopic guidance. The balloons were, in all cases, semicompliant with a profile of 5 mm, 6 mm, or 7 mm. Follow-up was for 42.9 ± 23.2 months (mean ± SD). Double-J stents were inserted postdilatation, the caliber and length depending on the patient's body weight.

Results: Intervention duration was 22 ± 19 minutes. Dilatation was not possible in 5 patients, and pyeloplasty was the alternative treatment. Hospital stay was 24 hours in 44 patients. Analgesic needs were met exclusively by nonsteroidal anti-inflammatory drugs. The double-J stent was withdrawn using cystoscopy and the UPJ was calibrated.Residual stenosis was found in 7 patients. A second dilatation was required in 3 patients 6-18 months after surgery because of the lack of improvement of hydronephrosis. During follow-up, resolution of the hydronephrosis was observed in 45 cases (anterior-posterior diameter of the renal pelvis 7 ± 5 mm). The diuretic renography improved in 45 infants; the shape of the curve being normal in 44 cases and semi-obstructive in 1.

Conclusion: We believe that high-pressure balloon dilatation could be a valid and safe option in the minimally invasive treatment of UPJ obstruction in infants. The outcome is acceptable with a low complication rate.