The ureters carry urine from the kidneys to the bladder. Each kidney has its own ureter. A ureterocele involves a widening of the lower part of the ureter, where it enters the bladder, due to a blockage caused by a membrane. Because urine cannot flow freely into the bladder, this membrane stretches out and fills with urine, resembling a water balloon.

Ureteroceles occur in about 1 in 500 to 1 in 4,000 people. Caucasians are most likely to be affected. It is equally common in both left and right ureters.

The defect occurs during fetal development. The size of the ureterocele determines when it will be diagnosed; large ureteroceles are generally discovered earlier in life than smaller ones.

Ureteroceles may be discovered before birth during a prenatal maternal ultrasound (pregnancy ultrasound). Children with this condition often come to medical attention for severe urinary tract infections. Sometimes people with ureteroceles don't know they have the condition, or the diagnosis is made later in life due to kidney stones. Uteroceles can also cause chronic unilateral (one-sided) or bilateral (both-sided) obstructive uropathy (swelling) of the affected kidney(s).

Uteroceles can be complicated by incorrect placement of the ureter (ectopic ureter) or other congenital anomalies, including ureteropelvic junction obstruction (blockage of the connection between the kidney and the ureter) or vesicoureteral reflux (backflow of urine from the bladder into the ureter) on the opposite side.

• Flank pain
  • Severe
  • May travel or radiate to the groin, genitals, thigh
  • Colicky or spasmodic
  • On one side
• Back pain, possibly only on one side
• Urinary tract infection
• Fever
• Dysuria (painful urination)
• Foul-smelling urine
• Abdominal pain
• Blood in the urine
• Increased urinary frequency/urgency
• Excessive urination at night
• Palpable abdominal mass
• Urinary incontinece
• Ureterocele prolapse (through the urethra in girls and visible in vagina)

Blood pressure may be elevated. A urinalysis may reveal blood in the urine or signs of urinary tract infection. A retrograde pyelogram, abdominal ultrasound, or CT scan of the abdomen may show a ureterocele and hydronephrosis. VCUG (voiding cysto-urethrogram), IVP (intravenous pyelogram), radionuclide renal scan, and cystoscopy (bladder endoscopy) may also be performed as part of the evaluation.

Treatment is focused on relief of the obstruction. Stents (drains placed in the ureter or in the renal pelvis) may provide short-term relief of symptoms.

Surgical repair of the ureterocele usually cures the condition. The surgical repair entails either making an incision of the ureterocele (popping the water balloon) or removing the ureterocele and reattaching the ureter to the bladder. This decision is dictated by the severity of the obstruction.

The outcome varies. If the obstruction can be cured, the damage may be temporary. However, damage to the kidney may be permanent, especially if the condition persists. Renal insufficiency or failure is uncommon because the other kidney usually continues to function adequately.

• Permanent kidney damage, with a decrease or loss of function (one kidney)
• Chronic or recurrent urinary tract infection
• Permanent bladder damage (incontinence/urinary retention)

Call your health care provider if symptoms indicate ureterocele may be present.