Vesicoureteral reflux
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.
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.