FP787COLOR DOPPLER ULTRASONOGRAPHY OF URETERIC JET: A VALUABLE METHOD FOR DETECTING VESICOURETERAL REFLUX IN INFANTS

Abstract

Introduction and Aims: Primary vesicoureteral reflux (VUR)isa congenital abnormality in which the urine flows back from the bladder towards the kidneys. VUR is a common defect in childhood and its incidence in children with urinary tract infection (UTI) ranges from 30 to 50%. To prevent hypertension and chronic renal failure, an early detection of VUR is needed. Voiding cystourethrography (VCUG) is the golden standard for diagnosing VUR but this approach is invasive and requires radiation exposure and catheterization. With this background in mind, we investigated whether ureteric jet studied by color Doppler ultrasonography (CDU) may be a nonin-vasive screening tool for detecting VUR in infancy. Methods:We enrolled33 patients [25 infants and8 children; 13 males and 19 females; median age: 5 months (from 2 to 58 months)] with febrile UTI admitted to the Pediatric Unit of our Hospital to undergo VCUG. A single investigator, blinded to VCUG, studied ureteric jet by CDU to identify the site of ureteral orifice in relation to bladder midline and lateral wall. A medial jet corresponded to an ureteral orifice close to bladder midline and was associated to highly unlikely VUR, a lateral jet coincided with an ureteral orifice close to bladder lateral wall and was associated to highly likely VUR and an intermediate jet, corresponding to an ureteral orifice placed between bladder midline and lateral wall, that was considered as uninformative. Results:Inour population, the prevalenceof VUR was 30.3%. Nine patients showed 18 ureteric medial jet that suggested the absence of VUR while the remaining 24 patients had at least one ureteric jet classified as lateral, intermediate or not evaluable, pointing to the presence of VUR or being uninformative about refluxing ureters. At VCUG, 10 patients showed at least 1 refluxing ureter while the remaining 23 patients were negative for VUR. By comparing the two imaging methods, only one patients with VUR escaped diagnosisby CDU. Ultrasonography showeda 90% specificityand 39% sensitivity clearly indicating that this approach is useful to identify patients with no VUR who can spare VCUG. Conclusions: Color Doppler Ultrasonography of ureteric jet site represents a fast, simple, highly specific and noninvasive method applicable as screening tool to identify patients with urinary tract infection without vesicoureteral reflux in infancy. This approach is of clinical relevance for predicting infants who can avoid cystourethrography.