Risk Factors for Failure of Endoscopic Balloon Dilatation of Primary Obstructive Megaureter: Single-Center 12-Year Experience with 123 Cases.

To review our experience with >100 patients with primary obstructive megaureter (POM) undergoing endoscopic balloon dilatation (EBD) and a follow-up of up to 12 years and determine potential risk factors for failure. Our hypothesis is that EBD allows for long-term treatment in >80% of patients, and its effectiveness decreases in more severe cases. This is a retrospective study of 123 consecutive patients (131 ureters) undergoing EBD from 2009 to 2021. Indications for EBD included symptoms, worsening dilatation, and/or renal function impairment. Clinical characteristics, complications, and outcomes, including those in the patients with >5-year follow-up, were described. Preoperative and intraoperative markers of severity chosen were tested as risk factors for failure. Failure was defined as the need for ureteral reimplantation after EBD. EBD was feasible in 121 of 123 (98%) patients, regardless of age. After a median follow-up of 38 (9-143) months, EBD was effective in 84.5% of cases. Failures generally occurred in the 1st year after EBD and were seldom associated with permanent loss of renal function. Of the 66 patients with follow-up >5 years, EBD was effective in 56 patients. No preoperative characteristic proved to be a risk factor for failure. The intraoperative absence of a ring was the only significant risk factor for failure, odd ratio 117.86 (95% confidence interval 6.27-2215.84). EBD was feasible and definitive treatment in 85% of our cases, regardless of age. Since this study did not identify preoperative factors to help the clinicians in patient selection, we consider EBD a viable initial procedure in all patients with POM who require surgical intervention, especially in infants.