Endoscopic balloon dilatation in primary obstructive megaureter: Long-term results

Summary Background Open neoureterocystostomy is the traditional surgical treatment for primary obstructive megaureter (POM). Endoscopic balloon dilation is a new minimally invasive alternative. It has been shown to be a safe and effective endoscopic procedure over short-term follow-up; however, few studies have shown its long-term efficacy. Objective The aim of this study was to evaluate the long-term results and complications of balloon dilation for the treatment of primary obstructive megaureter in infants. Materials and method A retrospective review was performed of patients with primary obstructive megaureter treated with balloon dilation. The diagnosis was made through ultrasonography, diuretic isotopic renogram, and voiding cystourethrogram (VCUG). The indications for surgery were: worsening hydronephrosis, renal function impairment, and recurrent urinary tract infections (UTI). All patients were followed 3 months after the endoscopic procedure with ultrasonography and MAG-3 renogram, and 6 months after surgery with VCUG and ultrasonography. Annual ultrasound and clinical follow-up were performed until present time. Results Seven boys and six girls were treated (median age 9 months, range 2–24). Ten patients had a prenatal diagnosis of hydronephrosis, and the diagnoses was made after UTI in three patients. No intraoperative complications were observed. One double-J stent was replaced after endoscopic procedure for malpositioning, and four patients developed UTIs after surgery. All patients had non-obstructive MAG-3 diuretic renogram 6 months after surgery. The mean washout on the renogram and the ultrasound pelvic diameter showed pre-operative and postoperative statistical differences ( Summary Table ). All patients maintained their results without recurrence or any other complications in the long-term follow-up. The median follow-up was 10.3 years (range 4.7–12.2). Discusion In 2014, Aparicio et al. first described balloon dilation being used as a definitive treatment for primary obstructive megaureter in infants. Bujons et al. also presented 20 cases with a mean follow-up of 6.9 years. The current study is the largest to date, with a median follow-up of 10.2 years. It demonstrated the value of balloon dilation as a definitive treatment for POM. Despite these results, it was difficult to establish endoscopic balloon dilation as a definitive treatment for POM, due to the absence of long-term studies like the current one. Conclusion Balloon dilation can be a safe and effective endoscopic procedure for the treatment of primary obstructive megaureter in infants, and has shown good outcomes in long-term follow-up. More studies are needed to demonstrate these results. Summary table . Preoperative and postoperative renal findings. Outcomes Pre-operative 6 months after surgery P -value (Wilcoxon test) Median distal ureter diameter, mm (range) 15 (7–22) 4 (3–9) P Median pelvis diameter, mm (range) 20 (13–25) 11 (3–15) P Median differential renal function MAG-3 renogram, % (range) 49.7 (29–58) 51 (43–56) P = 0.249 T½ MAG-3 renogram, minutes (range) 73 (25–150) 5.5 (5–20) P MAG-3, mercapto-acetyltriglycine.