Prognostic Value of Ultrasound Grading Systems in Prenatally Diagnosed Unilateral Urinary Tract Dilatation
We compared the prognostic value of anteroposterior intrasinus diameter of the renal pelvis, urinary tract dilatation and the Society for Fetal Urology grading system in children with prenatally diagnosed unilateral urinary tract dilatation.Materials and Methods:
All newborns with prenatally diagnosed unilateral urinary tract dilatation, normal bladder and anteroposterior intrasinus diameter 10 mm or greater on the first postnatal ultrasonography were prospectively enrolled from January 2011 to February 2015. Indications for surgery were recurrent febrile urinary tract infections and/or decrease of relative renal function more than 10% on serial isotope studies and/or increasing anteroposterior intrasinus diameter greater than 20% on serial ultrasounds. Sensitivity, specificity and ROC curves were calculated to evaluate the accuracy of anteroposterior intrasinus diameter, urinary tract dilatation and Society for Fetal Urology grading system in determining which children would need surgery within 24 months.Results:
A total of 57 males and 13 females were included. Of the patients 33 required surgery at a median age of 5 months (IQR 3.8 to 6.4). Urinary tract dilatation remained stable in 14 cases and decreased in 23 with a median followup of 42 months (IQR 25 to 67). Anteroposterior intrasinus diameter, urinary tract dilatation and Society for Fetal Urology scores were all correlated with the need for surgery. Anteroposterior intrasinus diameter with a threshold of 20 mm had the best prognostic value, with a sensitivity of 81.8% and a specificity of 91.7%.Conclusions:
Our study confirms that the prognostic value was comparable between anteroposterior intrasinus diameter of the renal pelvis, urinary tract dilatation and Society for Fetal Urology grading system in newborns with prenatally diagnosed unilateral urinary tract dilatation. Anteroposterior intrasinus diameter and abnormal parenchymal thickness are the most important ultrasound criteria to identify children at risk for requiring surgery.