Vesicoureteral reflux is the abnormal flow of urine from your bladder back up the tubes (ureters) from your kidneys. Normally, urine flows only down from your kidneys to your bladder.
Most commonly a condition of infancy and childhood, vesicoureteral reflux increases the risk of urinary tract infections. Untreated, it can lead to kidney damage.
There are two types of vesicoureteral reflux — primary and secondary. Children with primary vesicoureteral reflux are born with a defect in the valve that normally prevents urine from flowing backward from the bladder into the ureters. Secondary vesicoureteral reflux is due to a blockage, often caused by infection, in the urinary tract.
Children may outgrow primary vesicoureteral reflux. Treatment, which includes medication or surgery, is aimed at preventing kidney damage.
A urinary tract infection (UTI) is the most common indication of vesicoureteral reflux. Not everyone with a UTI develops recognizable signs and symptoms, but most people have some. These can include:
- A strong, persistent urge to urinate
- A burning sensation when urinating
- Passing frequent, small amounts of urine
- Blood in the urine (hematuria) or cloudy, strong-smelling urine
- Abdominal or flank pain
A UTI may be difficult to diagnose in children, who may have nonspecific signs and symptoms. Signs and symptoms in infants with a UTI may include:
- Lack of normal growth (failure to thrive)
- Vomiting and diarrhea
- Lack of appetite
As your child gets older, untreated vesicoureteral reflux can lead to other signs and symptoms, including:
- High blood pressure
- Protein in urine
- Kidney failure
Another indication of vesicoureteral reflux, which may be detected by sonogram of the fetus in the womb, is swelling of the urine-collecting structures of one or both kidneys (hydronephrosis), caused by the backup of urine into the kidneys.
Your urinary system comprises your kidneys, ureters, bladder and urethra. All play a role in removing waste from your body.
The kidneys, a pair of bean-shaped organs at the back of your upper abdomen, filter waste, water and electrolytes — minerals such as sodium, calcium and potassium that help maintain the balance of fluids in your body — from your blood. Tubes called ureters carry urine from your kidneys down to your bladder, where it is stored until it exits the body through the urethra during urination.
Vesicoureteral reflux can develop in two forms, primary and secondary:
- Primary vesicoureteral reflux. The cause of this more common form is a defect that's present before birth (congenital). The defect is in the valve between the bladder and a ureter that normally closes to prevent urine from flowing backward. As the child grows, the ureters lengthen, which may improve valve function and eventually resolve the reflux. This type of vesicoureteral reflux tends to run in families, which indicates that it may be genetic, but the exact cause of the defect is unknown.
- Secondary vesicoureteral reflux. The cause of this form is a blockage in the urinary system. The blockage most commonly results from a UTI, which may cause swelling of a ureter.
Laboratory analysis of urine (urinalysis), sometimes followed by a urine culture, can reveal whether your child has a UTI. Other tests are necessary to determine the presence of vesicoureteral reflux. They may include:
- Kidney and bladder ultrasound. Also called sonography, this imaging method uses high-frequency sound waves to produce images of the kidney and bladder. This same technology, which often is used during pregnancy to monitor fetal development, may also reveal swollen kidneys in the fetus, an indication of primary vesicoureteral reflux.
- Voiding cystourethrogram (VCUG). This test uses X-rays of the bladder when it's full and when it's emptying to detect any abnormalities. A thin, flexible tube (catheter) is inserted through your urethra and into your bladder while you lie on your back on an X-ray table. After contrast dye is injected into your bladder through the catheter, your bladder is X-rayed in various positions. Then the catheter is removed so that you can urinate, and more X-rays are taken of your bladder and urethra during urination to see whether the urinary tract is functioning correctly.
Risks asssociated with this test include discomfort, both from the catheter and from having a full bladder, and possibly, an allergic reaction to the dye in the form of bladder spasms.
- Nuclear scans. This test, known as radionuclide cystogram, uses a procedure similar to that used for VCUG, except that instead of dye being injected into your bladder through the catheter, this test uses a radioactive material (radioisotope). The scanner detects the radioactivity and shows whether the urinary tract is functioning correctly. Risks include discomfort from the catheter and discomfort during urination. Urine may be slightly pink urine for a day or two after the test.
Grading the condition
Vesicoureteral reflux can be graded according to severity. The most common grading system grades from the mildest condition, in which urine backs up only to the ureter (grade I), to the most severe, which involves severe swelling (hydronephrosis) and twisting of the ureter (grade V).
Treatment of vesicoureteral reflux depends on the severity of the condition. Children with mild cases of primary vesicoureteral reflux may eventually outgrow the disorder. In this case, your doctor will likely recommend a wait-and-see approach. During this time, it will be important for you to be watchful for potential UTIs and to seek prompt treatment.
There are two types of treatment for the condition: medication and surgery. Using medication is more common, with surgery usually reserved for those children for whom antibiotics aren't successful. The goal of treatment is to prevent kidney damage.
UTIs require prompt treatment with antibiotics to keep the infection from moving to the kidneys. Doctors also use antibiotics to prevent UTIs, usually at about half the dose for treating an infection.
Commonly used antibiotics include trimethoprim-sulfamethoxazole (Bactrim, Septra), trimethoprim (Proloprim) and nitrofurantoin (Furadantin, Macrodantin). Possible side effects of long-term use of these drugs include:
- Nausea and vomiting
- Abdominal pain
- Increased antibiotic resistance, in which the condition no longer responds to antibiotics and becomes more difficult to treat
A child being treated with medication will need to be monitored for as long as he or she is taking antibiotics. This includes periodic physical exams and urine tests to detect breakthrough infections — UTIs that occur despite the antibiotic treatment — and occasional X-rays of the bladder and kidneys to determine if and when your child outgrows vesicoureteral reflux.
For children with primary vesicoureteral reflux who don't outgrow the condition, surgery repairs the defect in the valve between the bladder and each affected ureter that keeps it from closing and preventing urine from flowing backward. There are two methods of surgical repair:
- Open surgery. Performed using general anesthesia, this surgery requires an incision in the lower abdomen through which the surgeon repairs the malformation that's causing the problem. This type of surgery usually requires a few days' stay in the hospital, during which a catheter is kept in place to drain your child's bladder. Risks include infection, blood clots and bleeding.
- Endoscopic surgery. In this procedure, your doctor inserts a lighted tube (cystoscope) through the urethra to see inside your child's bladder, then injects a bulking agent around the opening of the affected ureter to try to strengthen the valve's ability to close properly. This method is minimally invasive compared with open surgery and presents fewer risks. This procedure also requires general anesthesia, but generally can be performed as outpatient surgery.