Dilatação Endoscópica de Balão para Tratamento de Megaureter Obstrutivo Primário: Experiência de um Centro

Introduction: Congenital obstructive megaureter may be treated with endoscopic balloon dilatation, particularly in children under one year of age. We report our experience over a six year period. Patients and methods: All patients with diagnosis of primary obstructive megaureter (POM) treated with endoscopic balloon dilatation from 2009 to 2014 (6 years) were included. The diagnosis of POM was based on dilatation of the distal ureter greater than 7 mm, obstructive curve on MAG 3 diuretic renogram and absence of vesicoureteral reflux (VUR). After diagnosis, conservative management was maintained with antibiotic prophylaxis in all patients. The indications for surgery were a combination of clinical, ultrasonographic and renographic findings. Under general anesthesia and after retrograde ureteropielography, high pressure balloon dilation of the ureterovesical junction was performed under direct and fluoroscopic vision until the disappearance of the narrowed ring. A double-J catheter was positioned. Follow-up was performed with ultrasonography and diuretic renogram. The success of the intervention was defined by improvement of HUN (at least 2 grades). Results: A total of nine patients underwent this procedure on a single ureter, two girls and seven boys, with a mean age of 7. 6 months (range 1-14) at the intervention. Five were left sided and four were right sided. All patients had prenatal diagnosis of hydroureteronephrosis (HUN). No patients were lost to follow-up (average 46.7 months). They all had HUN greater than grade 3 and preoperative MAG3 diuretic renogram was obstructive in all cases.  Mean differential function of the affected kidney was 46.2% (range 40-53%). The main indication for surgical treatment was progressive HUN. All patients were treated endoscopically with no intraoperative complications. Ultrasound showed improvement of the HUN in six patients (66.7%). Three patients were reimplanted (33.3%). The mean differential renal function (DRF) after the procedure was 47.4% (range 41-53%). At the latest follow-up assessment, all patients remained asymptomatic. Discussion: Endoscopic balloon dilatation is a useful option in the management of POM requiring surgical intervention and may be considered first line treatment in small children.