Vesicoureteral Reflux

Normal urinary system	Urinary system with  reflux

http://www.urology.medsch.ucla

VUR is most commonly diagnosed in infancy and childhood after the patient has a urinary tract infection (UTI). About one-third of children with UTI are found to have VUR. VUR can lead to infection because urine that remains in the child's urinary tract provides a place for bacteria to grow. But sometimes the infection itself is the cause of VUR.

Pathophysiology: Reflux nephropathy is based on persistent reflux of sterile or infected urine from the bladder to one or both kidneys via the ureters. Although sterile VUR may cause renal scarring, most studies indicate that the appearance of renal scarring or the extension of established renal scars requires infection (Escherichia coli is the common pathogen). The higher the grade of reflux, the greater the likelihood of development of new or progressive scarring in association with infection.

Intrarenal reflux, or the extension of VUR into the collecting tubules of the nephrons that allows urinary microorganisms access to the renal parenchyma, is believed to be particularly important in the development of renal scarring.

Radiologic evidence of renal scarring is noted in 30-60% of children with VUR, and VUR is present in almost all children with severe renal scarring. A direct correlation between the prevalence of scarring and the grade of VUR has been demonstrated.

Although VUR occurs at a similar rate in boys and girls, girls are at greater risk of developing reflux nephropathy because of increased incidence of urinary tract infection (UTI). In the absence of reflux and UTI, abnormalities of organ systems other than the genitourinary tract do not place a child at increased risk for developing reflux nephropathy.


Frequency:
In the US: The incidence of renal scarring in children resulting from VUR is unknown. The prevalence of VUR in asymptomatic children is less than 0.5%, but VUR is present in 29-50% of children with UTIs.
Mortality/Morbidity: The incidence of renal scarring in children caused by VUR is unknown. VUR is present in 29-50% of children with UTIs.

Race: VUR and reflux nephropathy occur less frequently in black children than in other groups of patients.

Sex: Reflux occurs at a similar rate in boys and girls; however, the much higher incidence of UTI in girls places them at greater risk for reflux nephropathy.

Age: In children, the occurrence of VUR decreases with increasing age. The vesicoureteral insertion matures just prior to puberty. The mature bladder wall intramural portion of the ureter attains its 1.5-cm length.

Anatomy: Most VUR is considered primary because of incompetence of the ureterovesical junction (UVJ), and it is not secondary to either obstruction or infection. As the UVJ matures to assume its adult 1.5-cm oblique path through the bladder wall, VUR tends to decrease in severity and eventually disappears just before puberty. An exception is in patients with an anatomic abnormality, such as a bladder diverticulum, into which the refluxing ureter enters. Incompetence of the vesicoureteral junction resulting from a lack of maturation is the most common cause of vesicoureteral reflux in children. Obstruction and infection rarely cause reflux. With maturation of the incompetent vesicoureteral junction, reflux usually eventually resolves.

A small subgroup of children who have a perpendicular ureteric insertion at the bladder wall with a resultant golf-hole ureteric orifice. In these patients, surgical correction is necessary to eliminate VUR. A decision to perform a repair, either a ureteroneocystostomy or a collagen periurethral injection is dependent upon the appearance of the ureteric orifice. Nevertheless, all patient are covered with appropriate antibiotics to await the maturation of the intramural portion of the ureter or undergo surgery to stop the reflux.

Clinical Details: Children with reflux nephropathy may be asymptomatic, they may present with nonspecific symptoms (eg, failure to thrive, fever, poor food intake), they may be acutely ill in association with acute pyelonephritis, or they may present with renal failure with advanced renal scarring associated with reflux nephropathy.

Urinary reflux often takes urine back up to the kidneys, leading to the possibility of kidney infection (Pylonephritis) and permanent kidney damage (scarring) in young children.

Symptoms
Fever
Poor weight gain
Irritability
Pain on urination
Diarrhoea
Strong smelling urine
Vomiting
Cloudy urine
Bed wetting if previously dry
Blood in the urine
General ill health

There are two types of VUR. Primary VUR occurs when a child is born with an impaired valve where the ureter joins the bladder. This happens if the ureter did not grow long enough during the child's development in the womb. The valve does not close properly, so urine backs up (refluxes) from the bladder to the ureters, and eventually to the kidneys. This type of VUR can get better or disappear as the child gets older. The ureter gets longer as the child grows, and the function of the valve improves.

Secondary VUR occurs when there is a blockage anywhere in the urinary system. The blockage may be caused by an infection in the bladder that leads to swelling of the ureter. This also causes a reflux of urine to the kidneys.

Infection is the most common symptom of VUR. As the child gets older, other symptoms, such as bedwetting, high blood pressure, protein in the urine, and kidney failure, may appear.

Common tests to show the presence of urinary tract infection include urine tests and cultures.

Because no single test can tell everything about the urinary tract that might be important to know, more than one of the following imaging tests may be needed:

Kidney and bladder ultrasound: A test that uses sound waves to examine the kidney and bladder. This test shows shadows of the kidney and bladder that may point out certain abnormalities. The test cannot reveal all important urinary abnormalities or measure how well a kidney works.

Ultrasound showing VCR from http://www.emedicine.com

Voiding cystourethrogram (VCUG): A test that examines the urethra and bladder while the bladder fills and empties. A liquid that can be seen on x rays is placed in the bladder through a catheter. Pictures are taken when the bladder is filled and when the child urinates. This test can reveal abnormalities of the inside of the urethra and bladder. The test can also determine whether the flow of urine is normal when the bladder empties.

VCUG Results grading
Grade I Ureter only
Grade II Ureter pelvis, and calyces with out dilation.
Grade III Mild dilation of ureter, slight blunting of calyceal fornices
Grade IV Moderate dilation, loss of sharp calyceal fornices
Grade V Gross dilation of ureter and calyces

Grade III Mild dilation of ureter, slight blunting of calyceal fornices

Bilateral reflux extending into the pelvicalyceal systems of the kidney without dilatation of the calyces or ureters. (Note catheter in bladder)

 http://www.med.uwo.ca

Intravenous pyelogram: A test that examines the whole urinary tract. A liquid that can be seen on x rays is injected into a vein. The substance travels into the kidneys and bladder, revealing possible obstructions.

Nuclear scans: A number of tests using radioactive materials that are usually injected into a vein to show how well the kidneys work, their shape, and whether urine empties from the kidneys normally. Each kind of nuclear scan gives different information about the kidneys and bladder. Nuclear scans expose a child to about the same amount of radiation as a conventional x ray. At times, it can be even less.

Treatment
The goal for treatment of VUR is to prevent any kidney damage from occurring. Infections should be treated at once with antibiotics to prevent the infection from moving into the kidneys. Antibiotic therapy usually corrects reflux caused by infection. Sometimes surgery is needed to correct primary VUR.

Most cases of uncomplicated mild reflux will disappear over time. Meanwhile, your child will need to take a single, low dose of antibiotics daily to prevent kidney infection, and will need a voiding cystourethrogram and renal ultrasound once a year. Long-term antibiotic treatment is usually with trimetroprim/ sulfamethoxazole (Bactrim, Septra) or nitrofurantoin (Macrodantin, Furadantin, Macrobid). For infants under two months of age, amoxicillin or ampicillin is usually used. In addition, your doctor should check a urine culture 3-4 times per year.

There is a new procedure that we are now offering to treat vesicoureteral reflux. The medication used is called Deflux. During the 20-minute procedure the Deflux is injected into the lining of the bladder to make a new valve mechanism and stop the reflux. In 80% of the children who undergo this procedure, the reflux and the use of daily antibiotics are eliminated. The procedure is done under an anaesthetic as an out patient surgical procedure which is minimally invasive and does not involve any incisions.

Surgery
In some cases of reflux, your doctor may recommend surgery. Reasons for surgery include severe (Grade 4 or 5) reflux, which is not likely to get better on its own, infections despite daily antibiotics, and reflux which has persisted after several years of observation. During the surgery, the ureter will be disconnected from the bladder and then reimplanted so it can’t reflux. Our patients’ average hospital stay after this surgery, using state-of-the-art pain management techniques, is little more than a day. Although success rates for reimplant surgery are about 98 percent, surgical complications are possible.
 

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