[The correction of primary megaureter in children. The late results].

The surgical intervention on 261 ureterovesicular segments was performed in 202 patients aged 3 months-14 years. All the patients presented with megaureter varying in forms: refluxing megaureter (147 cases), nonrefluxing megaureter (94 cases), megaureter with ureterocele (20 cases). Histological investigations demonstrated congenital structural changes of the same type to be a morphological basis of diverse megaureter forms. These structural changes involved muscular and connective tissue elements of the ureteral wall. Being qualitatively continual, the components varied in quantity thus producing different maldevelopments. Urodynamic dysfunctions depended on ureteral dysplasia severity and form. Clear-cut outlines in the x-ray image of the refluxing, nonrefluxing and megaureter with ureterocele resulted from the condition and structure of the ostium ureteris and its submucosal segment. The same pathogenetic origin of megaureter forms gave grounds for conducting operations of the same type, resection of the defective ureter along with the ostium and its replacement for a morphofunctionally competent segment with formation of another ostium. The response to the surgery was assessed in 196 patients (249 ureters). The follow-up lasted from 1.5 to 22 years. Good responses were achieved in 90%, satisfactory in 3.2%, poor in 6.8% of the surgical patients. High efficacy of the operation says in favour of its pathogenetic validity. The megaureter correction created favourable conditions for renal growth and development. However, in 7 cases the improvement has changed for progressive nephrosclerosis with decline in the organ function or arterial hypertension. The ureter in such cases was in stable good condition. The above observations suggest the necessity of further investigations of this problem and continuation of the patients' follow-up.