Vesicoureteral reflux in children
Causes and risk factors
Reflux affects 1 to 18.5% of children and is more common in women (85%) and white children.
There are two main causes.
The first is a congenital abnormality at the junction of the ureter and bladder, which leads to primary reflux.
The second is an obstruction of the lower urinary tract, which leads to secondary reflux. The obstruction may be a valve in the posterior urethra (obstruction of urine flow at the level of the urethra), improper bladder function (neurologic bladder), bladder diverticulum (eversion of the bladder wall), or previous bladder surgery.
Which are the symptoms?
Symptoms depend on the age of the child.
In infants and young children, they are as follows:
- slow or stunted growth;
- poor appetite;
- body temperature above 38.5 °C;
- grayish or yellowish complexion;
- irritability or lethargy.
In children and young people, they are as follows:
- painful urination;
- frequent urination;
- body temperature over 38.5°C or pain in the side.
How is it diagnosed?
Prenatal ultrasound can detect enlarged renal pelvis and suspect vesicoureteral reflux before symptoms appear.
If reflux is suspected, a pediatric urologist evaluates the need for examinations such as:
- urinary cystography: involves inserting a catheter into the bladder, filling the bladder with a contrast agent, and taking several x-rays while the bladder is filling. This also allows the anatomy and function of the bladder and urethra to be studied;
- cystoscintigraphy: radioactive substances are used. These are indirect cystoscintigraphy if they are injected into a vein, and direct cystoscintigraphy if they are injected into the bladder through a catheter. Compared with cystography, these methods give the child a lower dose of radiation, do not allow the urethra to be examined, and are less accurate in determining the degree of reflux;
- intravenous urography: involves injecting radiopaque substances into a vein and taking repeated x-rays in succession. It gives an anatomical and functional examination of the kidneys and urinary tract;
- kidney scintigraphy: using radioactive substances injected into a vein, it enables a computerized examination of kidney function and possible obstruction to the outflow of urine.
How is it treated?
In the case of reflux, the kidneys are at risk of infection, which over time can lead to functional damage to the kidney. Therefore, it is very important to administer a low dose of antibiotic daily to protect the kidneys from infection.
Further treatment depends on the nature of the reflux (primary or secondary) as well as the degree and age of the child. Specifically, for cases of:
- primary reflux of degree I-II: in 80% of children it resolves spontaneously within 3 years with medication at home. Therefore, in these cases, surgical treatment is not carried out;
- primary reflux of degree III-IV-V: there are different opinions. Some advocate permanent treatment at home because it is believed that the reflux disappears over time. Others, including the San Raffaele team, believe that it is preferable to have a definitive surgery than to expose the child to kidney damage and long-term antibiotic therapy. The success rate for surgery is 98% with traditional open surgery and 80% with endoscopic surgery. Open vesicoureteral reimplantation is aimed at preventing the outflow of urine from the bladder to the kidneys by isolating and repositioning the ureters. A three-day hospital stay is required.
endoscopic correction of reflux, on the other hand, requires an overnight stay or is performed in a day hospital. Avoiding skin incisions, a cystoscope can be used to look inside the bladder, and substances are injected into the urethra to prevent urine backflow;
- secondary reflux: the pathology that caused the reflux is treated (e.g. neurological obstruction of the bladder and urethra).