RESUMEN
BACKGROUND: The grading of urinary tract dilatation (UTD) on postnatal sonography is a fundamental step to establish rational management for infants with antenatal hydronephrosis (ANH). The aim of this study was to compare the prediction accuracy of UTD grading systems for relevant clinical outcomes. In addition, we propose a refinement of the UTD classification by adding quantitative measurements and evaluate its impact on accuracy. METHODS: Between 1989 and 2019, 447 infants diagnosed with isolated AHN were prospectively followed. The events of interest were surgical interventions and kidney injury. Comparison of performance of the grading systems and the impact on the accuracy of a modified UTD classification (including the size of the kidney parenchyma) was assessed by the area under the receiver-operating characteristic curve (AUC). RESULTS: Of 447 infants, 131 (29%) underwent surgical intervention and 26 (5.8%) had developed kidney injury. The median follow-up time was 9 years (IQ range, 7-12 years). The performance for detecting the need for surgical intervention was excellent for all grading systems (AUC > 0.90). However, for predicting kidney injury, the modified UTD classification exhibited significant improvement in accuracy (AUC = 0.913, 95%CI, 0.883-0.937) as compared with UTD classification (AUC = 0.887, 95%CI, 0.854-0.915) (P = 0.027). CONCLUSIONS: Our study confirms that the hydronephrosis grading systems provide excellent accuracy in discriminating patients who need surgical intervention among infants with AHN. Our findings suggest that the inclusion of kidney parenchymal thickness to UTD classification might increase the accuracy for predicting infants who may develop kidney injury. A higher resolution version of the Graphical abstract is available as Supplementary information.
Asunto(s)
Hidronefrosis , Sistema Urinario , Dilatación , Femenino , Humanos , Hidronefrosis/diagnóstico por imagen , Hidronefrosis/etiología , Lactante , Riñón/diagnóstico por imagen , Masculino , Embarazo , Estudios Retrospectivos , Ultrasonografía Prenatal , Sistema Urinario/diagnóstico por imagenRESUMEN
PURPOSE: The aim of this study was to evaluate the performance of the new classification of urinary tract dilatation (UTD) to predict long-term clinical outcomes in infants with isolated antenatal hydronephrosis (ANH). MATERIALS AND METHODS: Between 1989 and 2019, 447 infants diagnosed with isolated severe ANH and were prospectively followed. The main predictive variable for the analysis was the new UTD classification system. The events of interest were surgical interventions, urinary tract infections, chronic kidney disease stage II or higher, hypertension and proteinuria. The primary end-point was time until the occurrence of a composite event of renal injury, including proteinuria, hypertension and chronic kidney disease. RESULTS: Among 447 infants with ANH included in the analysis, 255 (57%) had UTD P1, 93 (20.8%) UTD P2 and 99 (22.2%) UTD P3. Median followup time was 9 years (IQR 7-12 years). Of 447 patients included in the analysis, 11 (2.5%) had hypertension, 13 (2.9%) exhibited persistent mild proteinuria, 14 (3%) developed chronic kidney disease Stage 2 and 26 (5.8%) had the composite outcome of renal injury. By survival analysis, the UTD system predicted accurately all events of interest. According to the Kaplan-Meier survival analysis, the probability of renal injury at 20 years of age was estimated at about 0%, 14% and 56% for patients assigned to UTD P1, UTD P2 and UTD P3, respectively (p <0.001). CONCLUSIONS: Our findings provide insights that the new UTD classification has a good performance for discriminating not only mid-term, but also long-term clinical outcomes, including renal injury.