Vesicoureteral Reflux

What is Vesicoureteral Reflux?

Vesicoureteral reflux is a common disorder of the urinary system. The urinary system is made up the kidneys, ureters, bladder and urethra. The body has two kidneys that drain urine to the bladder by small tubes called ureters. Urine normally travels in only one direction, i.e from the kidneys to the bladder. Vesicoureteral reflux (VUR) occurs when urine travels backward from the bladder through the ureters to the kidneys. Vesicoureteral reflux without urinary infection by in large is harmless. However, when associated with urinary infection, VUR may cause severe kidney infections (pyelonephritis) which can lead to kidney damage.

What Causes Vesicoureteral Reflux?

There are two types of VUR: primary and secondary. Primary VUR is the most common and is usually caused by an irregular embryological arrangement of the ureteral tube in the bladder early in the development of the fetus before birth. When the ureter enters the bladder, the tunnel for which it travels in the bladder may be too short or have too large of a diameter to allow the ureter to close sufficiently during bladder filling to prevent a backup of urine. This condition may resolve as the child grows with the bladder enlarging and the ureter changes in length. Secondary VUR occurs when there is an associated condition, such as: bladder outlet obstruction, overactive bladder, myelomeningocele, voiding abnormalities and dysfunctional elimination problems.

Who is Susceptible to Vesicoureteral Reflux?

VUR occurs in less than 1% of healthy children. In children with a urinary tract infection (UTI), the incidence is 25 to 50%. One study found that 38% of children with antenatal (before birth) kidney swelling (hydronephrosis) were diagnosed with VUR on subsequent studies after birth. While boys had a higher incidence antenatally, females still make up 85% of the children with VUR overall. Caucasian girls had 10 times the risk of VUR versus African-American girls.

Further studies have shown a higher incidence of VUR (30-40%) in siblings of children who were already diagnosed with VUR. If you have a child with vesicoureteral reflux, it is important to talk with your physician to determine if other siblings should be evaluated for VUR.

How is Vesicoureteral Reflux Diagnosed?

There are two different types of patients who are diagnosed with VUR; 1- children with prenatally detected kidney swelling (hydronephrosis); 2- Children being evaluated for urinary tract infection. Some children are detected before birth when hydronephrosis is discovered via a prenatal screening ultrasound. These children are frequently evaluated after birth with a renal ultrasound and voiding cystourethrogram (VCUG). A VCUG is performed by placing a catheter in the urethra (natural voiding channel) and X-ray visible dye is injected into the bladder allowing X-rays to delineate the flow of the urine.

The second group of children may require an evaluation for VUR after a urinary tract infection. While opinions vary, it is generally accepted that the following children with a UTI should be evaluated for VUR with a renal ultrasound and VCUG: any child less than 5 years of age, a child with a UTI and fever (regardless of age), and any boy with a UTI (unless they are sexually active or have a significant past history of genitourinary problems).

Your healthcare provider may recommend another form of imaging called a radionuclide scan. This procedure allows the provider to continue to monitor the VUR with minimal radiation exposure. A DMSA scan may be ordered to detect scarring of the kidney or an infection in the kidney (pyelonephritis).

The VCUG is important in helping to stage the severity of VUR.

• Grade I: urine refluxes into the ureter only
• Grade II: urine refluxes into the ureter and renal pelvis (collecting system of the kidney) without distention of the pelvis.
• Grade III: urine refluxes into the ureter and renal pelvis with only mild dilatation (hydronephrosis)
• Grade IV: the child also has moderate hydronephrosis
• Grade V: The child has severe hydronephrosis and abnormalities of the ureter.

What are the Symptoms of Vesicoureteral Reflux?

Vesicouretral reflux itself is usually asymptomatic and a urinary infection is the presenting picture. Children may present initially with the following signs of a urinary tract infection: fever, malodorous urine, blood in the urine, urinary frequency, pain with urination, bedwetting, protein in the urine, lethargy or gastrointestinal symptoms. Newborns may have nonspecific symptoms such as poor feeding and irritability.

What are the Complications of Vesicoureteral Reflux?

Vesicoureteral Reflux without urinary infection for the most part does not cause injury to the kidneys. However, VUR with infection can result in an infection of the kidney (pyelonephritis) which can result in scarring of the kidney. Fortunately, significant kidney scarring is rare. Significant scarring of the kidneys can result in high blood pressure, renal impairment, renal failure, and complications in pregnancy as an adult. Prophylactic antibiotic treatment to prevent urinary infections in children is begun immediately after diagnosis of VUR to try and decrease the risk for these complications.

How is Vesicoureteral Reflux Treated?

The management and treatment of VUR depends upon many factors and an in depth discussion of VUR and your child should be individualized with your health care provider. Vesicoureteral reflux is frequently initially managed by a primary care provider for lower grades of VUR (1-3) . Higher grades of VUR or complex and complicated cases of VUR are usually jointly managed with a surgical specialist called a Pediatric Urologist.

VUR has a spontaneous resolution rate and is usually managed with prophylactic antibiotics (preventative antibiotic) in hope that with growth of the child there will be concomitant growth of the ureteral tunnel. Should the tunnel grow enough then the VUR may resolve without the need for a surgical procedure. Prophylactic antibiotics are given at very low doses daily to reduce possible side effects. Newborns are usually given Amoxicillin or Keflex (Cephalexin). Children older than 2 months can be given Trimethoprim (Primsol) or Bactrim (trimethoprim-sulphamethoxazole). Waiting 12-18 months is the usual time to wait between follow up X-rays so that a child has time to grow.

Spontaneous resolution of VUR has one major caveat. It is impossible to predict when or if the VUR will improve or resolve. Some children with high grade VUR can have resolution in a short time frame and some children with low grade VUR will never have spontaneous resolution. Fortunately most children with Grades I-III VUR will have improvement or resolve their urinary reflux by the time they are 2 to 5 years of age. Children with Grades IV & V urinary reflux have a lower resolution rate of VUR. These children too can be followed but frequently require a surgical procedure to bring closure to the VUR

When is Surgery recommended for VUR?

If a child has a breakthrough infection (urinary tract infection on the preventative antibiotic) the conservative plan of monitoring the reflux must be abandoned and a surgical procedure is necessary to prevent further potential infections of injuring the kidneys. In general infants are at greater risk for renal injury than older children.

Surgery is also an option if a child has had persistent VUR after years of follow-up with little or no improvement. However, if no infections have occurred surgery is not mandatory. In the older child, many families frequently select surgery to bring closure to the problem, allow the discontinuance of antibiotics, and avoid any further potential side effects of VUR.

What type of Surgery is available for VUR

Surgical treatment is offered in 2 ways; open ureteral reimplantaion surgery and minimally invasive endoscopic deflux injections. The gold standard is open surgery that involves rearranging the ureters in the bladder in a non-refluxing natural position. Open surgery is > 95% successful and usually does not require a repeat VCUG x-ray after surgery. The surgical procedure is performed through a 4cm low abdominal incision, just above the pubic bone, below the underpants line. The child routinely only spends the night of surgery in the hospital and generally gets back to normal activity in 3-5 days (4-6 years old). Infants and toddlers rarely need surgery but, if required, are frequently back to themselves within 1-2 days.

Minimally invasive deflux injection involves performing a telescopic exam (endoscopic) of the bladder through the urethra as an outpatient procedure. This access allows direct injection of a dextramoner bead paste (sugar beads) under the ureter that improves or cures VUR in about 80% of the time. Children are back to normal activity usually the same day. A VCUG x-ray is necessary to assess the treatment after the procedure.

About the Author

Peter D. Furness III, M.D., FAAP, FACS:

Dr. Furness is Associate Professor of Surgery and Pediatrics at the University of Colorado Health Sciences Center and the Associate Chief of Pediatric Urology at the Children's Hospital in Denver, Colorado.

Copyright 2012 Peter D. Furness III, M.D., All Rights Reserved