Factores predictores de la evolución en la hidronefrosis prenatal

espanolOBJETIVO: Determinar predictores independientes prenatales y postnatales de una mala evolucion de la funcion renal, de la resolucion espontanea o de la necesidad de cirugia en la hidronefrosis prenatal. METODOS: Estudio retrospectivo en pacientes con hidronefrosis prenatal. Analizamos diferentes variables clinicas prenatales y postnatales, asi como, el DAP (diametro anteroposterior) de la pelvis renal en la ecografia prenatal del tercer trimestre, y en la primera y segunda ecografia postnatal. Las analizamos mediante t de Student, chi-cuadrado, analisis de supervivencia, y curvas de COR. RESULTADOS: Se incluyeron 218 pacientes con 293 UR (unidades renales). Operadas 147/293 (50,2%) UR, resolucion espontanea 76/293 (25,9%) UR, y 76/293 (25,9%) UR presentaron mala evolucion. Encontramos como factores de riesgo para la cirugia el bajo peso al nacer (OR 3,84; IC 95% 1,24-11,84), la prematuridad (OR; 4,17 IC 95% 1,35-12,88), la duplicidad (OR 4,99; IC 95% 2,21-11,23) y la presencia de patologia nefrourologica subyacente (OR 53,54; IC 95% 26,23-109,27). Para la no resolucion espontanea se encontraron las alteraciones en el volumen del liquido amniotico (RR 1,46; IC 95% 1,33-1,60) asi como la patologia nefrourologica subyacente y la duplicidad. Para la mala evolucion la alteracion del volumen del liquido amniotico (OR 11,99; IC 95% 2,70-53,21), la presencia de patologia nefrourologica subyacente (OR 4,81 IC 95% 2,60-8,89) y la cirugia (OR 4,23 IC 95% 2,35-7,60). El DAP en las tres ecografias es fiable para la prediccion de cirugia (area bajo la curva 0,65; 0,82; 0,71), para resolucion espontanea (area bajo la curva 0,80; 0,91; 0,80) y solo el DAP de la primera ecografia postnatal para mala evolucion (area bajo la curva 0,73). Los DAP con mayor sensibilidad y especificidad son los de la primera ecografia postnatal; 14,60mm para cirugia; 11,35mm para resolucion espontanea; y 15,50mm para mala evolucion. CONCLUSION: A mayor DAP en la pelvis renal en cualquiera de las tres ecografias las probabilidades de cirugia y de no resolucion espontanea son mayores. La primera ecografia es la mas fiable para predecir la evolucion en la hidronefrosis prenatal. Existen otros factores a tomar en cuenta para predecir la evolucion de los pacientes con HN prenatal. EnglishOBJECTIVES: To determine prenatal and postnatal independent predictors of poor outcome, spontaneous resolution, or the need for surgery in patients with prenatal hydronephrosis. METHODS: We performed a retrospective study of patients with prenatal hydronephrosis. The renal pelvis APD was measured in the third prenatal trimester ultrasound, as well as in the first and second postnatal ultrasound. Other variables were taken into account, both prenatal and postnatal. For statistical analysis we used Student t-test, chi-square test, survival analysis, log-rank test, and ROC curves. RESULTS: We included 218 patients with 293 renal units (RU). Of these, 147/293 (50.2%) RU were operated. 76/293 (25.9%) RU had spontaneous resolution and other 76/293 (25.9%) RU had poor outcome. As risk factors for surgery we found low birth weight (OR 3.84; 95% CI 1.24-11.84), prematurity (OR 4.17; 95% CI 1.35-12.88), duplication (OR 4.99; 95% CI 2.21-11.23) and the presence of nephrourological underlying pathology (OR 53.54; 95% CI 26.23-109.27). For the non-spontaneous resolution, we found as risk factors the alterations of amniotic fluid volume (RR 1.46; 95% CI 1.33-1.60) as well as the underlying nephrourological pathology and duplication. In the poor outcome, we found as risk factors the alterations of amniotic fluid volume (OR 4.54; 95% CI 1.31-15.62), the presence of nephrourological pathology (OR 4.81 95% CI 2.60- 8.89) and RU that was operated (OR 4.23, 95% CI 2.35-7.60). The APD of the renal pelvis in all three ultrasounds were reliable for surgery prediction (area under the curve 0.65; 0.82; 0.71) or spontaneous resolution (area under the curve 0.80; 0.91; 0.80), only the first postnatal ultrasound has predictive value in the poor outcome (area under the curve 0.73). The higher sensitivity and specificity of the APD as predictor value was on the first postnatal ultrasound, 14.60 mm for surgery; 11.35 mm for spontaneous resolution and 15.50 mm for poor outcome. CONCLUSION: The higher APD in the renal pelvis in any of the three ultrasounds, the greater the chances of surgery and failure of spontaneous resolution. The first postnatal ultrasound is the most reliable in predicting outcome of prenatal hydronephrosis. There are other factors to take into account to predict the outcomes of these patients.