Vesicoureteral reflux
Vesicoureteral reflux is a condition in which urine backs up from the bladder into the kidneys. Produced by the kidneys, the urine travels down small tubes (ureters) into the bladder where the urine is stored prior to voiding (urinating). At the junction between the ureters and the bladder, a valve mechanism normally keeps the urine from backing up or refluxing back into the ureter and kidney. When this valve is faulty, reflux can occur. In the absence of an active kidney infection, reflux does not cause pain, problems with urination, or any other symptoms.
Why the concern with urinary reflux?
Urine is stored in the bladder and is normally clean (no bacteria). Bacteria may, at times, enter into the urinary tract from the skin around the urethra. If this happens, the bacteria can infect the bladder causing pain with urination and/or frequency. This is known as a bladder infection.
In the absence of reflux, the infection stays in the bladder and does not travel to the kidneys. If a child also has reflux, the infected urine in the bladder can now travel to the kidneys and cause a kidney infection (pyelonephritis). Kidney infections are much more serious than bladder infections. Children are much more ill with high fevers. More importantly, kidney infections may cause permanent damage to the kidney which is known as "renal scarring." Thus, the combination of a bladder infection and the presence of reflux allows for the development of a kidney infection. It is important to realize that reflux did not cause the bladder infection, it simply allowed the bladder infection to turn into a kidney infection.
What is a urinary tract infection?
A urinary tract infection (UTI) is an infection anywhere in the urinary tract. In general, this occurs in one of two places. When it occurs in the bladder, it is known as a bladder infection or cystitis. When it occurs in the kidney, it is known as a kidney infection or pyelonephritis. Therefore, a UTI can either be a bladder infection or kidney infection. It is important to distinguish between the two since bladder infections alone do not place the kidney at risk for damage. Kidney infections are the types of infection in children that can cause them to be ill with high fevers and result in permanent damage to the kidney. Learn more about urinary reflux in the developing fetus as discussed in the Institute for Fetal Health pages.
UTI's and reflux are linked only when reflux allows a bladder infection to turn into a kidney infection. Reflux does not cause UTI's, and UTI's do not cause reflux.
How common is reflux?
It has been estimated that reflux may be present in up to two to three percent of the general population. Reflux is usually congenital, which means the child was born with the condition. No one knows what causes reflux. Since reflux does not cause symptoms, it is usually only diagnosed after the development of a UTI. It is more common in girls than boys and is most found when the child is approximately two to three years of age.
Is reflux hereditary?
Urinary reflux is present at birth and does run in families. Siblings of patients with reflux have a much greater risk of having it (33%) than the normal population. If a parent has a history of reflux, there is a 66% chance that their children will have reflux. Screening for reflux is still controversial and should be discussed with your physician.
How is reflux diagnosed?
In general, if children have a history of UTI's, especially kidney infections, they should be evaluated for reflux. The test to evaluate for reflux is known as a cystogram. There are two types of cystograms -- a voiding cystourethrogram (VCUG) and nuclear cystogram (NVCUG).
Both tests are similar and are considered invasive since they involve the placement of a urethral catheter. Dye is placed through the catheter into the bladder to see if reflux is present. Your child will be asked to void during this study since reflux sometimes only occurs during voiding. When the test is administered properly in a "kid friendly" environment with personnel that are trained to treat children, the procedure is usually not traumatic or overly uncomfortable; most children do not require sedation.
Your doctor may order other tests such as an ultrasound. An ultrasound of the bladder and kidneys is a non-invasive test that uses sound waves to view the kidney, ureters and bladder. This test allows for determination of kidney size and growth. It also allows the clinician to see if there is swelling in the kidneys. An ultrasound is NOT a test to determine if reflux is present.
Your child may also have test done know as a nuclear renal scan. This test helps to monitor kidney function and to see if renal (kidney) scarring is present. It requires the placement of a small intravenous catheter (small catheter in vein) in the arm. A dye is given through the intravenous catheter and pictures are taken for a few hours to look at the function of the kidneys.
How is the severity of reflux graded?
Reflux is graded on a scale from I to V. Grade I is the mildest or lowest grade of reflux and and grade V is the most severe. One of the important aspects of the grading system is to allow us to estimate the chances of whether or not a child will require surgery. In general, most children with grade I through III have a very good chance of outgrowing their reflux without the need for surgery. However, it may take many years. The higher grades of reflux are much more likely to require surgery.
How do we treat reflux?
Reflux can be managed with medical treatment and/or surgical treatment. Most low-grade reflux will resolve without surgery. High-grade reflux may need surgery but is it uncommon for surgery to be recommended first before medical therapy. The goal of reflux management is to protect the kidneys from infection and scarring. Since reflux is only dangerous in the presence of a bladder infection -- when the infection can spread from the bladder to the kidney -- the key to medical management is to bladder infection prevention. This involves the use of a "prophylactic antibiotic," which is usually given once a day. If the child remains infection free, a routine ultrasound and cystogram is performed every one to two years to monitor growth and to evaluate for persistent reflux.
The decision to perform surgical correction of reflux is not always an easy one and can be complicated. This should be discussed carefully and earnestly with your physician. However, some of the factors that may lead your physician to recommend surgery include the following:
- Recurrent infections despite the use of prophylactic antibiotics
- Worsening reflux
- Persistence of reflux for several years
- High-grade reflux
- Delayed kidney growth
- The presence of renal scarring
There are many different ways to surgically correct reflux. The traditional and most effective surgery is "open" surgery in which a transverse incision is made just above the pubic bone (beneath the "bikini line"). The ureters are detached from the bladder and tunneled into a stronger portion of the bladder. This surgery is more than 95% successful in fixing the reflux. Patients usually require one to two days in the hospital after surgery.
Another newer surgical option is the endoscopic correction of reflux or the "STING" procedure in which a FDA-approved foreign material (DEFLUX) is injected in the area where the ureter meets the bladder to strengthen the valve mechanism. This procedure is approximately 70 to 80% successful is stopping reflux. While not as successful as open surgery, the advantages of the endoscopic approach are that it is a short outpatient procedure and not associated with negative outcomes. However, the long-term results of the endoscopic approach are not known. And if the endoscopic approach is unsuccessful, correcting the reflux with conventional open surgery is not prohibited.
Lastly, laparoscopic (operating through telescopes) procedures have recently been developed for correction of reflux, and these are now being performed at a few centers around the world. The efficacy and potential advantages of this approach are still under investigation.
Other related fatcs about reflux
Recent research has demonstrated that there are two important factors that may be relevant to your child if he or she has reflux.
- Dysfunctional voiding -- Dysfunctional voiding is an acquired abnormal urinating pattern. The most common kind occurs in girls in which the bladder becomes overstretched and enlarged from a pattern of "holding" and waiting until the last second prior to voiding. This results in abnormal bladder dynamics that places the individual at increased risk of bladder infection. Also, this pattern of urinating can decrease the chance for spontaneous resolution for reflux. Thus, it is extremely important to evaluate children for dysfunctional voiding when they have reflux since if left untreated, it can increase the risk of bladder infection and reduce the chances that the reflux will spontaneously resolve.
- Constipation -- Most children that have dysfunctional voiding also have constipation. Many times the constipation will be little noticed because the children may be having a daily bowel movement. However, the bowel movement can still be constipated in nature with a significant amount of retained stool in the rectum and colon. This retained stool can push on the bladder and further adversely affect bladder dynamics. Once again, this places the children at greater risk for infection and lessens their chance for spontaneous resolution of reflux.