Can endoscopic balloon dilation for primary obstructive megaureter be effective in a long-term follow-up?

BACKGROUND Ureteral tapering and reimplantation is an established treatment for persistent or progressive primary obstructive megaureter (POM) but may result in complications and morbidity. Use of a less invasive technique involving endoscopic balloon dilation appears very interesting. OBJECTIVE The objective of this report is to determine if endoscopic balloon dilation for POM is effective in the long term as well as to assess complications of the procedure. MATERIAL AND METHODS A retrospective review was done on 19 patients and 20 ureters treated with the endoscopic balloon dilation by POM from June 2000 to February 2010. Surgery was performed solely in those cases in which there was persistence of obstruction in the renogram along with one or all of the following conditions: impairment of the differential renal function <40%, worsening of the renal pelvic dilation, febrile UTI in spite of antibiotic prophylaxis or renal calculi. The patients comprised 16 boys and 3 girls with a mean age at surgery of 17 months (range 1-44 months). Ten cases were left sided, eight right sided, and one bilateral. Under endoscopic and fluoroscopic guidance, a 3-5 Fr dilating balloon was inflated to 12-14 atm, or until disappearance of the stenotic obstructive area. A double J stent was positioned and withdrawn 2 months later. Follow-up recorded the presence of symptoms, number of reintervention procedures registered, and included renal ultrasound and MAG-3 renogram. RESULTS There were no perioperative complications. Eighteen ureters showed a non-obstructive pattern on MAG-3 renogram after the first endoscopic dilation, representing a 90% success rate. One case required a second dilation, which proved successful and two cases of recurrent lithiasis required ureterotomy without instances of obstruction. 2 patients had a febrile UTI and a vesicoureteral reflux was diagnosed in one. Renal function was preserved in 95% of patients. The mean follow-up was 6.9 years (range 3.9-13.3 years). One patient was lost after the procedure. DISCUSSION In an era of minimally invasive techniques, the search for less invasive procedures for treatment of POM has resulted in a variety of surgical options. Angulo et al., in 1998 and our group described the first POM treatment with endoscopic balloon dilation, which is believed to be a definitive, less invasive, and safe treatment. Furthermore, should an endoscopic approach fail, reimplant surgery can be performed. Few publications have reported short series with good results in the short and medium term. Torino et al. presented five cases in children aged less than 1 year, none of these showed evidence of obstruction. García-Aparicio et al. presented a series of 13 patients treated with a success rate of 84.6%. Christman et al. added laser incision in cases of narrowed ureteral segment 2-3 cm long and used double stenting. Good outcomes were presented in 71%. Romero et al. reported improvement of drainage within the first 18 months after treatment in 69% of patients. The potential de novo onset of vesicoureteral reflux may be the source of some controversy. We consider that dilation does not significantly alter the antireflux mechanism. In VCUG is not systematically performed because it is an invasive test. This restricts the conclusions that can be drawn from our findings. Nevertheless, some groups continue to systematically perform VCUG. CONCLUSIONS Endoscopic balloon dilation for POM is a safe, feasible, and less invasive procedure that shows good outcomes on long-term follow-up. However, multicenter studies and prospective trials should be encouraged to provide more definitive evidence on its benefits.