What is a ureterocele?

In a normal urinary tract, each kidney is connected to one ureter. The ureter is the tube that drains urine into the bladder. A ureterocele is a ballooning at the end of the ureter inside the bladder. It appears as a thin-walled balloon inside the bladder.

Ureterocele Illustration

Not all ureteroceles are the same:

  • Ureteroceles vary in size; some are barely seen while others can take up most of the bladder.
  • Ureteroceles can be inside the bladder (intravesical) or extend outside the bladder, through the bladder neck and urethra (ectopic or extravesical).
  • The opening of the ureterocele into the bladder can be narrow (causing some degree of obstruction), normal in size or larger in size.
  • Ureteroceles can be associated with a single system (one kidney and one ureter) or a duplex kidney (one kidney with two separate ureters).
  • Ureteroceles can be associated with vesicoureteral reflux (VUR). VUR occurs when urine in the bladder flows back into one or both ureters and often back into the kidneys.

Testing and diagnosis

Due to the increase use of prenatal ultrasounds, many babies are found to have hydronephrosis before they are even born. An ultrasound of the kidneys and bladder is done within the first few days after birth, as part of the postnatal management of babies with hydronephrosis. It’s during the ultrasound to diagnose hydronephrosis when an ureterocele is identified. In some babies the ureterocele can be seen on the prenatal images.

Because vesicoureteral reflux and obstruction can be associated with a ureterocele, it can predispose children to a urinary tract infection (UTI). Once the UTI is diagnosed, further radiology workup can identify the ureterocele. Your child may be placed on a low dose of antibiotics to inhibit the growth of bacteria and prevent further UTIs. This is called antibiotic prophylaxis.

Your child may undergo a variety of studies to help us confirm the diagnosis and better understand the extent of the condition.

  • Renal bladder ultrasound: This procedure uses sound waves to outline the kidneys and bladder. If a ureterocele is present, it can be identified during the bladder views.
  • Voiding cystourethrogram (VCUG): A catheter is placed through your child’s urethra into the bladder. The tube will be used to slowly fill the bladder with a solution. While the bladder is being filled, a special machine (fluoroscopy) is used to take pictures. As the bladder fills, the ureterocele can be identified. Also, the radiologist looks to see if any of the solution is going back up into the kidneys, which confirms the diagnosis of VUR.
  • MAG III renal scan: This study will be performed to determine how each kidney is functioning and will determine the degree of blockage, if any. During this test, an intravenous line (IV) is used to inject a special solution called an isotope into the veins. The isotope makes it possible to see the kidneys clearly. Pictures of the kidneys will be taken will a large X-ray machine that rotates around your child.
  • MRI/MRU: MRI is a radiation-free diagnostic procedure that uses a combination of a large magnet, radiofrequencies and a computer to produce detailed images of the body. Magnetic resonance urography (MRU) creates detailed pictures of the kidneys, ureters and bladder.


Not all ureteroceles are the same, many can be managed simply, others may require more extensive surgery. Our physicians will discuss the treatments options that are most appropriate for your child.

Treatment of a ureterocele depends on many factors:

  • The size of the ureterocele
  • The degree of obstruction
  • The function of the kidney
  • Whether or not VUR is present
  • Whether the bladder has been affected


Endoscopic surgery: This is usually an outpatient procedure under general anesthesia. During surgery a lighted tube, called a cystoscope, is inserted into the urethral opening to see inside the bladder — no incisions are made. When the ureterocele is identified, a small incision is made to puncture it.

Ureteral reimplantation: Under general anesthesia and through a lower abdominal incision, the ureterocele is removed and the ureter is reimplanted where it joins the bladder. The floor of the bladder and bladder neck may need to be reconstructed to improve urinary continence. At CHOP this procedure can be done through a minimally invasive surgery (MIS) using a laparoscopic or robotic approach. The minimally invasive approach is accomplished through three small incisions, the size of a grain of rice. The advantages are smaller, less visible incisions and overall, a quicker recovery period. The minimally invasive technique is not appropriate for all children.

Upper pole nephrectomy: If the ureterocele is associated with a duplex kidney, and the upper pole of the kidney is found to have no function, an upper pole nephrectomy may be recommended. This procedure can be done through a minimally invasive surgery.

Reviewed by Jennifer Kirk, BSN, MSN, CPNP

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