RESUMO
Objective:Objectives To investigate the predictive value of color Doppler flow imaging (CDFI) for the proteinuria following pyeloplasty for congenital ureteropelvic junction obstruction (UPJO) in children.Methods:We identified a series of 206 children with a mean age of (20.0±28.8) months (1-132 months), consisted of 171 males and 35 females, diagnosed with congenital UPJO accepted pyeloplasty from January 2014 to September 2018, the preoperative mean urinary Albumin/Creatinine Ratio (ACR) was (17.3±160.1) mg/mmol and the mean β2-microglobulin/Creatinine Ratio (β2-MG/Cr) was (135.6±383.8) μg/mmol, ultrasound showed a mean renal pelvis dilatation of (3.1±1.5) cm and a mean cortical thickness of (0.3±0.1) cm, and classified as grade Ⅰ-Ⅴ according to the blood flow distribution in renal by CDFI, these children were divided into three groups of increased, decreased and unchanged blood flow according to the postoperative CDFI within 1 week, the postoperative urinary protein and renal function indexes within 1 week and 2 years were retrospectively analysed among groups.Results:Within 1 week postoperatively, an increased, decreased and unchanged blood flow occurred in 113 (54.9%), 31(15.0%), 62(30.1%) children, respectively. Urinary ACR in above mentioned groups was (112.3±400.7), (16.1±29.3), (32.7±48.4) mg/mmol, β2-MG/Cr was (887.4±6061.0), (50.2±62.7), (51.9±57.8)μg/mmol, there were significant differences among groups ( P<0.01). Contralateral hydronephrosis occurred in 21(18.6%), 4(12.9%), 8(12.9%) children, urinary N-Acetyl-β-D-glucosaminidase (NAG) was (7.5±5.2), (7.0±5.4)、(5.7±4.5) U/L, these indexes showed no significant differences among groups. There was a positive correlation between the increased blood flow level and the decreased renal pelvis dilatation (Spearman’s correlation coefficient 0.2, P<0.01), ACR (Spearman’s correlation coefficient 0.4, P<0.01) and β2-MG/Cr (Spearman’s correlation coefficient 0.3, P<0.01). After a follow up of 2 years, 67 children were diagnosed with proteinuria in this series, 51 cases of them with an increased blood flow, which had significantly higher percentage than children with a decreased (4 cases, 12.9%) or unchanged blood flow (12 cases, 19.3%). Logistic multivariate analysis indicated that early postoperative (within 1 week) increased blood flow ( OR=1.9, 95% CI 1.5-2.6), contralateral hydronephrosis ( OR=2.2, 95% CI 1.1-4.8) and urinary NAG ( OR=1.1, 95% CI 1.0-1.1) were predictive of proteinuria, the increased blood flow was independent predictor of proteinuria (Ⅰ level increased: OR=1.9, 95% CI 1.5-2.6). Conclusions:The CDFI reveals good predictive value for the postoperative proteinuria, an early marked increased blood flow postoperatively indicated risk of proteinuria in the long term.