Text Box: SURGICAL TREATMENT OF GENTLE HYDRONEPHROSIS IN CHILDREN ACCOMPANIED BY ABDOMNALGIA Li Zhaozhu, Li Gang, Zhang Zhaoping, Wang Fenglan, Sun Yan, Han Fuyou, Tao Wenfang Dept. of Pediatric Surgery of the 2nd Affiliated Hospital of Harbin Medical University, China Objective: Most children ill with gentle hydronephrosis were treated by nonsurgical therapy. We want to know the changes of hydronephrosis degree, renal function and renal blood flow (RBF) when the patients with gentle hydronephrosis occured abdomnalgia and to conform the necessity and occasio of surgical treatment. Methods: We investigated 20 children who ill with gentle hydronephrosis and followed by color Doppler ultrasoud, IVP, CT and lab examinations per 3-6 month and at the time when the patients occur abdomnalgia. If the hydronephrosis became serious and/or obstruction of ureter appeared, the patients would be operated and histopathological studies were performed. Results: Twenty patients ill with gentle hydronephrosis. Age ranges from 6m to 10y. At the beginning the hydronephrosis degree of all children were light and RI<0.66±0.11 by RBF, and there were not obstruction of ureter by IVP and CT, and the renal function were nomal. We found 7 patients had abdomnalgia occur and 1 case had hematuria through 6m to 5y follow-up. Hydronephrosis became serious, and the kidney was larger and renal cortex was thinner, and RI>0.70, and obstruction of ureter appeared. Six of them were performed Anderson-Hynes procedure. Another patients refused operation and were treated by antibiotics and were observed. We found there were congenital pelviureteric junction stenosis at the six patients, and two of them were obstruction completely, and two of them accompanied abnomal pelviureteric junction. Histopathologic exam have found that there were acute damage of the kidney and extravasation of urine especially. All six patients recover after operation. Conclusion: Congenital hydronephrosis can express acute obstruction during chronic disease course and accompany by serious injury of renal cortices in a short obstructive time. The first and important symptom is abdomnalgia. The obstruction of pelviureteric junction may be caused and aggravated by urologic infection. So sometimes the obstruction can relieve temporarily through usage of antibiotics. But the obstruction can occur repeatly and the renal function will be reduced. It is necessary that emergency and sub-emergency surgical treatment should be considered when the patients with light hydronephrosis occur abdominalgia. 1709