What is bladder ureteral reflux?
Bladder ureteral reflux is divided into primary and secondary types. Primary bladder ureteral reflux is the most common congenital urinary tract abnormality in children. Normally, urine flows from the kidneys into the bladder through the ureters, which should be a one-way path. However, about 1% of newborns have incomplete development of their urinary structures, leading to the backflow of urine into the kidneys, known as primary bladder ureteral reflux. If bacteria reach the kidneys in such cases, it can lead to acute pyelonephritis. Secondary reflux has many causes, including neurogenic bladder and lower urinary tract obstruction due to various reasons.

What are the symptoms?
Fever, pus in the urine, and older children may experience lower back pain. Urinary reflux can be observed on prenatal ultrasound. If children under two years old repeatedly have urinary tract infections and ultrasound shows hydronephrosis, potential bladder ureteral reflux needs to be ruled out.

Grading of bladder ureteral reflux
It is usually classified into five grades:

Grade I: Urine reflux into the ureters with mild dilation.
Grade II: Urine reflux into the kidneys with normal-sized renal pelvis.
Grade III: Reflux into the kidneys with dilated renal pelvis.
Grade IV: Reflux causing severe dilation of the ureters and renal pelvis.
Grade V: Reflux causing twisted ureters and severe hydronephrosis.

How is it treated?
There are both medical and surgical treatments. Mild bladder ureteral reflux, followed up for five years, has a self-recovery rate of about 80%. Regular follow-ups are generally recommended, and antibiotics are used if urinary tract infections occur. Severe cases (Grade IV-V reflux) have a self-recovery rate of less than 40% after five years. Children with frequent urinary tract infections might need to discuss surgical treatment options, such as local injection of hyaluronic acid or ureteral reconstruction surgery, with a clinical physician. In cases of severe bilateral kidney scarring, kidney function can gradually deteriorate, leading to end-stage kidney disease, ultimately requiring kidney transplantation.