Vesicoureteral Reflux

How does vesicoureteral reflux occur?

The urine formed in the kidneys flows down to the urinary bladder via the ureters. Urine normally flows in one direction, down the ureter, and into the bladder. During urination and when the bladder is filled with urine, there is a valve between the bladder and the ureter responsible for preventing urine from returning. Vesicoureteral reflux occurs as a result of a defect in the mechanism of this valve.

Based on the backflow of urine from the bladder to the ureters and kidneys, the severity of vesicoureteral reflux is graded from mild to severe (according to the classification from grade 1 to grade 5).

What causes vesicoureteral reflux?

There are two types of vesicoureteral reflux: primary vesicoureteral reflux and secondary vesicoureteral reflux. Primary vesicoureteral reflux is the most common type of vesicoureteral reflux and appears at the time of birth. Secondary vesicoureteral reflux can appear at any age and is usually the result of obstruction or dysfunction of the bladder or urethra with a bladder infection.

There are no specific signs or symptoms of vesicoureteral reflux. But recurrent UTIs are the most common symptom and a sign of vesicoureteral reflux. In older children with severe, untreated vesicoureteral reflux, signs and symptoms are evident because of complications such as high blood pressure, protein in the urine, or kidney failure.

How can vesicoureteral reflux be diagnosed?

The following are the examinations performed on children suspected of having vesicoureteral reflux:

1. Basic diagnostic test for Vesicoureteral reflux

• VCUG is the most reliable method for diagnosing (grading) vesicoureteral reflux and determining its severity.
• Vesicoureteral reflux is classified according to the degree of reflux. 
• The vesicoureteral reflux classification refers to the flow of urine back to the ureters and kidneys. 
• The classification is important to determine the prognosis and the most appropriate treatment.

2. Additional tests for Vesicoureteral reflux

• Urine tests and urine cultures are used to detect urinary tract infections.

• Blood tests: The basic tests usually performed are to measure the level of hemoglobin, the number of white blood cells, and the level of creatinine in the blood.

• Ultrasound of the kidneys and bladder: to detect the size and shape of the kidneys and to detect scars, kidney stones, obstructions, or other abnormalities. Reflux (urinary backflow) cannot be detected.

• Kidney examination for dimercaptosuccinic acid: This test is the best way to detect kidney scars.

How is vesicoureteral reflux treated?

It is important to treat vesicoureteral reflux to prevent possible infection and kidney damage. Treatment of vesicoureteral reflux depends on the degree of reflux and the child's age and symptoms. There are three treatment options for vesicoureteral reflux, which are antibiotics, surgical intervention, and laparoscopic treatment. 

The most common first-line treatment for vesicoureteral reflux is the use of antibiotics to prevent UTIs. Surgical intervention and endoscopic therapy are reserved for severe vesicoureteral reflux or for those patients for whom antibiotic treatment is not successful.

Mild vesicoureteral reflux:

It will completely disappear on its own by the time the child reaches the age of 5–6 years. Therefore, children with vesicoureteral reflux are less in need of surgical intervention. These patients are given a low dose of antibiotics once or twice daily over a long period to prevent UTIs. 

This is called antibiotic prophylaxis. Antibiotic prophylaxis is usually given at five years of age. And remember, antibiotics by themselves do not correct vesicoureteral reflux. Nitrofurantoin and co-trimoxazole are the drugs of choice for antibiotic prophylaxis.

All children with vesicoureteral reflux should follow the general precautions against UTIs (discussed above) and regular and frequent voiding. Regular urine tests are necessary to detect a urinary tract infection. The voiding cystourethrogram and ultrasound examination are repeated annually to determine if reflux has subsided.

Surgical interventions and endoscopic treatments are used to treat vesicoureteral reflux or when antibiotic therapy does not work.

Severe Vesicoureteral Reflux: 

The severe form of vesicoureteral reflux is less likely to disappear on its own. Therefore, children with severe vesicoureteral reflux should resort to surgical intervention or endoscopic treatment.

Correction of reflux by open surgery (ureteral reimplantation or ureteroureteropelvic anastomosis) prevents urine from regurgitating. The main advantage of the surgical intervention is its high success rate (88-99%).

Laparoscopic therapy represents a second effective treatment modality for severe vesicoureteral reflux. The benefit of the laparoscopic technique is that it can be performed on an outpatient basis. It takes 15 minutes and has fewer risks and does not require any openings in the skin. 

Endoscopic treatment is carried out under general anesthesia. In this method, with the help of an endoscope (lighted tube), a special filler (e.g., dextranomer/hyaluronic acid-deflex copolymer) is injected into the area where the ureter enters the bladder. The injection of the filler increases resistance to entering the ureter and prevents urine from flowing back into it. 

The success rate of correcting reflux with this method is about 85 to 90%. Endoscopic treatment is considered a convenient treatment option in the early stage of vesicoureteral reflux, as it avoids using antibiotics for long periods, and patients suffering from stress for years due to vesicoureteral reflux.

Follow-up: All children with vesicoureteral reflux should be screened for life, with height, weight, blood pressure, urinalysis, and other tests measured as recommended.

This article was written and reviewed by Dr. Hassan Ali - Urologist