Vesicoureteral Reflux (VUR)

What is vesicoureteral reflux?

Vesicoureteral reflux (VUR) is a condition that alters the movement of urine, causing it to flow backward from the bladder and up into the ureters or kidneys. It is more common in boys than in girls.

There are different types of VUR according to their severity. The International Reflux Study Committee classifies them as follows:

• Grade I: reflux reaches the ureter without dilating it.
• Grade II: reflux reaches the ureter, pelvis and renal calyces, but without dilating them.
• Grade III: reflux produces a small dilatation of the ureter, pelvis and renal calyces.
• Grade IV: moderate ureteropelocaliceal dilatation.
• Grade V: there is an important ureteropielocaliceal dilatation, with great tortuosity and loss of the normal caliceal morphology.

What are the causes?

Vesicoureteral reflux appears as a result of a defect in the maturation of the mesonephric mesoderm.

However, it is still unknown why it occurs, although in most cases it is due to an anomaly in the functioning of the ureterovesical sphincter.

What are the risks?

Vesicoureteral reflux increases the risk of urinary tract infections and, in more advanced cases, can also lead to scarring and kidney damage.

In addition, the patient may eventually develop chronic renal failure and need a kidney transplant.

How is it diagnosed?

The most commonly used techniques are serial voiding cystourethrogram (CUMS), isotopic cystography (IC) and contrast-enhanced voiding ultrasonography.

• Serial voiding cystourethrogram. This method allows visualization of the anatomy of the urinary tract, the urethra and accurate determination of the presence of posterior urethral valves. It also provides information about the severity of VUR.
• Isotopic Cystography. There are two types of IC: direct or indirect.

The former detects reflux more reliably and has less radiation on the gonads than the former technique.

Indirect isotopic cystography, on the other hand, allows the diagnosis of VUR without urethral catheterization and allows dynamic studies during urination under physiological conditions. Isotopic cystography is recommended to follow up the anomaly and to assess the persistence or resolution of VUR.

• Voiding contrast echocystography. It does not require the use of ionizing radiation due to its high sensitivity and specificity for detecting VUR. However, it has a serious drawback and that is that it does not allow adequate visualization of the urethra, its cost is high and requires a lot of time.

What is the treatment to be followed?

Vesicoureteral reflux is treated with antibiotics and, only in severe cases, surgery is resorted to. In fact, surgical treatment is avoided when there is significant renal involvement with dilatation and looseness of the ureter.

Conservative treatment with antibiotics includes the following recommendations:

• Apply hygienic measures.
• Use of low and repeated doses of antibiotics on a daily basis.

Recent studies have shown that the prolonged use of antibiotics is related to the appearance of bacterial resistance and decreases their efficacy in reducing the number of infections. For this reason, antibiotics are only administered to specific groups at high risk of renal damage.

Surgical treatment is individualized and is based on the anatomical correction of VUR. There are two surgical modalities:

1. Endoscopic technique with injection of macrosubstances under the ureteral orifice.
2. Surgical technique of ureteral reimplantation using Cohen’s transtrigonal technique or Leadbetter Politano’s extravesical technique.

However, in most cases surgical treatment is combined with antibiotic prophylaxis, since the objective is twofold. On the one hand it tries to fight the urinary tract infection and, on the other hand, to suppress the reflux to the kidney.

Other recommendations:

• Abundant and frequent fluid intake, to stimulate frequent emptying of the bladder and achieve hypotonic urine in which germs are more vulnerable.
• Correct voiding habits.
• Combat constipation to avoid secondary bladder dysfunction.

Which specialist treats it?

The urologist will be the specialist in charge of the diagnosis and treatment of vesicoureteral reflux, since it includes the study and treatment of diseases affecting the uro-genital apparatus, both male and female.