Ureterocele: a cyst-like swelling at the end of the ureter

What is a ureterocele?

When the ureter ends in a narrow opening where it enters the bladder, its last part swells like a balloon and looks like a thin-walled cyst inside the bladder. This is called a ureterocele. Because urine drains with difficulty through this narrow opening, the ureter and kidney above it also become dilated.

About 80% of ureteroceles occur with a duplex kidney and arise in the ureter that drains the upper part of the kidney. They are 4–7 times more common in girls than in boys.

Types

• Intravesical (inside the bladder) ureterocele stays completely inside the bladder.
• Ectopic ureterocele extends to the bladder neck or into the urethra. It causes more problems.

Symptoms

Today, most ureteroceles are found by ultrasound during pregnancy. In cases not found earlier:

• febrile urinary tract infection, often in the first months,
• weak urine stream, inability to pee (when the ureterocele blocks the bladder outlet),
• in girls, swollen tissue coming out of the urethra (prolapse),
• in older children, abdominal pain or stones.

Diagnosis

Ultrasound is the main test: it shows a thin-walled cystic structure in the bladder, a dilated ureter and a duplex kidney. To plan treatment, three questions need answers: how well each part of the kidney works, whether there is reflux, and whether urine drainage is blocked. A VCUG (voiding cystourethrogram) is done to check for reflux, a DMSA scan to find out how well each part of the kidney works, and if needed a MAG3 renogram or MR urography to assess drainage.

Treatment

A newborn whose ureter and kidney are dilated because of the ureterocele (hydroureteronephrosis) is started on a small daily dose of antibiotic to prevent infection (antibiotic prophylaxis).

Further treatment is tailored to each child. It takes into account the child’s condition and age, the function of each part of the kidney, reflux or blockage on either side, blockage of the bladder outlet, whether the ureterocele is inside the bladder or ectopic, and the preferences of the family and the surgeon.

• Endoscopic incision (puncture). A small opening is made in the wall of the ureterocele through a cystoscope, and urine starts to drain freely. There is no skin incision. If the ureterocele is infected and drainage is blocked, the urine must be drained promptly: either by an endoscopic incision or by placing a thin tube through the skin into the kidney (nephrostomy). More details: cystoscopy.
• Monitoring. If the upper part of the kidney does not work at all and there is no blockage or reflux, monitoring alone is possible in some children.
• Reconstructive operations. If reflux develops after the endoscopic incision or the problem continues, the ureter is reattached to the bladder, and sometimes the non-functioning upper part of the kidney is removed.