Topic Resources Reflux nephropathy is renal scarring presumably induced by vesicoureteral reflux of infected urine into the renal parenchyma. The diagnosis is suspected in children with urinary tract infections or a family history of reflux nephropathy, or if a prenatal ultrasound shows hydronephrosis. Diagnosis is by
voiding cystourethrography or radionuclide cystography. Children with moderate or severe reflux are treated with prophylactic antibiotics or surgical correction. Reflux requires incompetent ureterovesical valves or mechanical obstruction in the lower urinary tract. Young children with shorter intravesical portions of the ureter are most susceptible; normal growth usually results in spontaneous cessation of intrarenal and vesicoureteral reflux by age 5. New scars in children
> 5 years are unusual but may occur after acute pyelonephritis. Few symptoms and signs other than occasional UTI are present in young children, and the diagnosis is often overlooked until adolescence, when
patients present with some combination of the following: Polyuria Nocturia Hypertension Symptoms and signs of renal insufficiency
Reflux nephropathy may be suspected prenatally or postnatally. Initial screening is done with ultrasonography. The diagnosis is suspected prenatally if ultrasonography, done because of a family history or for unrelated reasons, shows hydronephrosis; 10 to 40% of such patients are diagnosed postnatally with vesicoureteral reflux (VUR). Vesicoureteral reflux is suspected postnatally in patients with any of the following:
Laboratory abnormalities may include proteinuria, sodium wasting, hyperkalemia, metabolic acidosis, renal insufficiency, or a combination. Testing for these patients is with radionuclide cystography or voiding cystourethrography. Because these tests involve catheterization (and risk of UTI) as well as radiation exposure, thresholds for obtaining them can be controversial. Some experts recommend VCUG or RNC only if family history is strong or if postnatal renal ultrasonography is markedly or persistently abnormal; however, it is not clear whether renal ultrasonography is sufficiently sensitive to detect VUR. DMSA scanning may be done for infants or children with UTIs as listed above. In older children in whom reflux is no longer active, VCUG may not show reflux, although DMSA scanning shows scarring; cystoscopy can demonstrate evidence of previous reflux at ureteral orifices. Thus, DMSA scanning and cystoscopy may be done if prior reflux is suspected but not confirmed. Renal biopsy at this late stage shows chronic tubulointerstitial nephritis and focal glomerulosclerosis, which may cause mild (1 to 1.5 g/day) to nephrotic-range (3.5 g/day) proteinuria.
Treatment of reflux nephropathy is based on the unproven assumption that decreasing reflux and UTIs prevents renal scarring. Children with very mild VUR require no treatment, but they should be closely observed for symptoms of UTI. Children with moderate reflux are usually given antibiotics. However, drug therapy predisposes to new episodes of acute pyelonephritis, and it is not clear whether prophylactic antibiotics are more effective than close observation. Patients with severe reflux are at higher risk of renal insufficiency and are usually given antibiotic prophylaxis or undergo surgical interventions, including ureteral reimplantation or endoscopic injection of materials behind the ureter to prevent reflux (bladder contraction during voiding compresses the ureter between the bladder and the material). Incidence of new renal scars is similar in patients treated with surgery and with drugs. Reflux spontaneously resolves in about 80% of young children within 5 years.
 Copyright © 2022 Merck & Co., Inc., Rahway, NJ, USA and its affiliates. All rights reserved. What radiologic examinations can demonstrate ureteral reflux?Voiding cystourethrography (VCUG) is the screening urologic imaging study of choice. American urologists, pediatricians, and radiologists recommend this study to detect vesicoureteral reflux (VUR), ureterocele, posterior urethral valves in boys, or bladder wall thickening.
Which of the following exams is used to demonstrate vesicoureteral reflux?A voiding cystourethrogram is the imaging of choice to diagnose vesicoureteral reflux (VUR). Recurrent UTI, first febrile urinary tract infection (UTI) with abnormal renal ultrasound (US) are indications of VUR.
Which of the following examinations of the urinary system demonstrates function?IV studies such as the IVU demonstrate function. Cystourethrography is an examination of the bladder and urethra, frequently performed during voiding. Nephrotomography is performed after IV administration of a contrast agent; it may be used to evaluate small intrarenal lesions and renal hypertension.
Which position may be helpful to demonstrate the lower ureters?Urinary System. |
Which of the following radiologic examinations can demonstrate ureteral reflux?
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