Vesicoureteral (vesico = bladder; ureteral = ureter) reflux is the backward flow of urine from the bladder to the kidney. This is common in puppies, but is felt to be an abnormal situation in humans. It is more common in premature infants and appears to be more common in girls than boys. It is usually discovered after the child has had a urinary tract infection or during a workup for abnormal kidneys noted on fetal ultrasounds before birth.

Understanding the Normal Urinary Tract

The kidneys are fist-sized organs located just in front of the lower fibs in the back. They filter blood and extract waste products to make urine. Urine passes from the kidneys into the renal pelvis and then down the ureter and into the bladder. The bladder is a storage organ, and when it contracts it pushes the urine out through the urethra. This is all supposed to be a one-way flow to the outside.

There is a natural valve-type mechanism where the ureter passes through the bladder wall into the bladder. The ureter passes through at an angle so that a "flap valve" is created. When the pressure of the urine in the bladder rises, the flap valve closes and keeps the urine from running backwards (reflux) into the ureter and kidney.

The one-way valve creates an important barrier that helps prevent bacteria, which may have entered from the outside though the urethra into the bladder, from reaching the kidneys.

Another important function is that it allows the bladder to empty more completely. If urine goes backward to the kidneys when the child has finished urinating, the urine drains quickly back into the bladder and creates a residual urine. This stagnant urine can easily become infected.

Vesicoureteral Reflux

The natural valve system may be abnormal for many reasons. The usual reason is the ureter passes through the bladder wall too directly, rather than tunneling at an angle through the bladder wall (see drawings). Often this problem will correct itself as the child grows and the valve mechanism matures. Vesicoureteral reflux may also occur if the child is generating strong pressures in the bladder secondary to strong bladder contractions (spasms). An obstruction below the level of the bladder that prevents the urine from coming out, except under high pressure, can cause vesicoureteral reflux. The ureter sometimes enters the bladder in an abnormal location (ectopia). Children with neurogenic bladders (myelomeningocele, etc.) may also have vesicoureteral reflux.

Why is Reflux a Problem?

The primary problem with reflux is that it puts the kidneys at risk for infection. Kidney infections are much more serious than bladder infections. Kidney infections may lead to permanent scarring in the kidney and may inhibit the growth of the kidneys. The infection can also lead to stones. High blood pressure can develop later in life due to the scarring in the kidney. If the infections and reflux involve both kidneys and are quite severe, renal failure may result and this may require treatment with dialysis or transplantation, however, this is quite rare.

As mentioned above, if the bladder is not able to effectively empty because urine passes up toward the kidneys and then flows back into the bladder, this leads to an increased rate of urinary tract infections because of the "stagnant" urine in the bladder.

How Do We Evaluate?

When a child has had urinary tract infection or there are other reasons to suspect vesicoureteral reflux, the kidneys and bladder are studied. The kidneys are often studied by ultrasound or by an intravenous pyelogram (x-rays after dye injection).

The bladder is studied by a voiding cystourethrogram (VCUG) x-ray. This is performed by passing a small catheter into the bladder and filling the bladder with x-ray dye. A nuclear voiding cystourethrogram may be done for followup. It is a more sensitive test and has less x-ray exposure, but it is more difficult to classify the degree of reflux with the nuclear voiding cystourethrogram. The bladder studies also help to rule out obstruction problems below the level of the bladder.

How Do We Classify Reflux and Why?

Reflux is classified into five grades. Grade 1 is the least amount of reflux. Grade 5 is the worst. It is generally expected that children with grades 1 and 2 will probably outgrow the reflux without requiring surgery (80%). Higher grades of reflux (4 and 5) usually require surgery. Grade 3 is borderline as to whether the child will outgrow the reflux or require surgery (50:50).

How Do We Treat Reflux?

Non-Operative (Medical) Management of Reflux

Eighty percent of children with mild degrees of reflux will spontaneously outgrow the reflux within a few years. We have no specific way of determining which individual child will outgrow the reflux and at what age that will happen.

Usually refluxing children are given a good opportunity to outgrow the reflux without surgery. During that time the kidneys must be protected from urinary tract infections. To do this, we use continuous low-dose antibiotics (prophylactic antibiotics). The child must be on these small doses of antibiotics until the reflux has resolved. Approximately every 18 months the reflux will be re-evaluated by x-ray studies and ultrasound. We are checking to be certain that the kidneys are growing and not scarring, and to determine if the reflux is still present.

When reflux stops the antibiotics may be stopped. It must be noted that there are no antibiotics that are risk free and that no one antibiotic will destroy all bacteria. Commonly used antibiotics are Bactrim or Septra (same medication) or Furadantin and Macrodantin. These medications seem to be well tolerated in small doses over long periods of time. In older children we may consider stopping antibiotics to determine if the child will have urinary tract infections (UTIs).

If a fever develops or the child develops symptoms such as frequency, burning or a foul odor to the urine, a urinary tract infection must be considered and a urinalysis and perhaps a urine culture must be done. If breakthrough urinary tract infections occur, in spite of the low-dose antibiotics, the child may become a candidate for surgical intervention.

Many children wet their pants or do the pee-pee dance. These children are often having bladder spasms that aggravate the reflux and cause more urinary tract infections, or they may be infrequent voiders. The treatment may require timed voiding, better bowel habits, and possibly medications such as Ditropan and Oxybutynin.

Surgical Operations for Reflux

If the child does not outgrow the reflux in a reasonable number of years, is approaching puberty, has breakthrough urinary tract infections, increasing scarring of the kidneys, will not take his antibiotics, or becomes allergic to many antibiotics, etc., the child may be a candidate for surgical treatment.

Ureteral reimplantation (Ureteroneocystostomy): The traditional surgical approach involves an incision in the lower abdomen just above the pubic bone. The incision is extended into the bladder and then the valve mechanism is corrected. This is done by using the patient's own tissue. No artificial valves are used. The surgical approach has a very high degree of success, 97%. The usual hospital stay is one to two days. Complications include bleeding and infection. Bladder spasms (contractions of the bladder against the catheter) also are common. There may be urinary leakage. It is possible that scar tissue may cause obstruction to the ureter or the child may continue to have vesicoureteral reflux. If this occurs, the reflux will usually resolve later. Surgery is done primarily to protect the kidney. Bladder infections may continue to be a problem. Incontinence may also continue.

Deflux: Reflux can be corrected by injecting a material under the lower end of the ureter. This is done under anesthesia through a small telescope, as a minimally invasive procedure. This can be done as an outpatient procedure and can save the patient the incision and hospitalization related to the traditional operation. Deflux is the material used. It is made of two materials, complex polysaccharides - (dextranomer) and hyaluronic acid, both of which are naturally found in our bodies. Deflux material was approved by the FDA in 2001.

Sibling Reflux

Brothers and sisters (siblings) of a patient with reflux have a one in three chance (33%) of also having reflux. It is, therefore, recommended that the siblings under the age of six be considered for ultrasound and a bladder x-ray (VCUG).

1. No antibiotics (not recommended in younger children).
2. Daily small dose of prophylactic antibiotics.
3. Subureteric injection of Deflux.
4. Open Ureteral reimplantation (ureteroneocystostomy).