The study of the difference between the melamine stone induced hydronephrosis and congenital hydronephrosis in infants: clinical features and their 24-month follow-up

To study the difference of clinical features in hydronephrosis induced by urinary melamine stone (HNMS) with that due to congenital ureteropelvic junction obstruction (HNUPJO) in infants. Forty six infants (18.5 +/- 10.0 months) with HNMS and 85 infants (20.4 +/- 9.3 months) with HNUPJO were included. All HNMS and 30 HNUPJO infants with mild pelvic dilation similar to those of HNMS were followed up for 24 months. Renal ultrasonography, renal function and urinalysis were evaluated at admission and follow up. The clinical features of two groups were compared. At admission, unilateral hydronephrosis occurred in 35 (76%) HNMS and 77 (91%) HNUPJO. More bilateral hydronephrosis were found in HNMS than in HNUPJO (24% vs. 9%, P < 0.05). HNMS showed more symptomatic and less abdominal mass appeared comparing with those of HNUPJO. Five cases of acute renal failure were observed in HNMS and none in HNUPJO. The degree of hydronephrosis of HNMS was significantly smaller than those of HNUPJO (P < 0.05). At 24-month of follow-up hydronephrosis resolved in 93% HNMS whereas remained stable in 80% HNUPJO. While 5 cases with HNUPJO deteriorated and pyeloplasty had to be performed. Only one HNMS infant needs surgical treatment due to the radiolucent stone has changed to radio-opaque stone, which induced significant ureteral obstruction. Significant difference of clinical feature existed between HNMS and HNUPJO. HNMS appears to be relatively benign. Non-operative management with close follow-up is a reliable and efficacious method for these HNMS infants. [Jian Guo Wen, Yan Wang, Rui Zhang, Lu Xing, Zhenzhen Li, Qing Wei Wang, An Feng Lou, Shengjun Zhang, Jens Christian Djurhuus, Jorgen Frokiaer. The study of the difference between the melamine stone induced hydronephrosis and congenital hydronephrosis in infants: clinical features and their 24-month follow-up. Life Science Journal. 2012;9(1):408-412] (ISSN:1097-8135). http://www.lifesciencesite.com. 60