A ureterocele is a congenital anomaly (present at birth) that affects girls more than boys. It is simply a swelling limited to the end of the ureter as it enters the bladder. The swelling resembles a balloon on ultrasound or during a camera examination of the bladder.
Ureteroceles in duplex anomalies can be associated with urine refluxing backward to the kidney through the second adjacent ureter. This reflux is related to weakness of the flap valve from having the ureter join the bladder in an abnormal location.
What happens under normal conditions?
Normally, the kidneys filter and remove waste and excess water from the blood to produce urine. Urine travels from the kidneys down narrow tubes called ureters. The ureters bring urine to the bladder, where it is then stored.
There is a flap valve between the ureters and the bladder to keep urine flowing in only one direction. If urine wrongly flows back to the kidneys, this is a problem called vesicoureteral reflux (VUR).
When the bladder empties, urine flows out of the body through the urethra. This is the tube that starts at the bottom of the bladder. The urethra travels to the end of the penis in boys, or out the front of the vagina in girls.
What is a ureterocele?
A ureterocele happens when the end of ureters that enters the bladder don’t develop properly. It is considered to be a birth defect. The ureteral end swells like a balloon that may stop the flow of urine to the bladder.
- Swell a lot, taking up most of the bladder or swell only a small amount.
- Be inside the bladder (intravesical) or outside the bladder, through the bladder neck and urethra (ectopic or extravesical).
- Happen with a single ureter or a double ureter (duplex collecting system). In 90% of girls with a ureterocele, the problem is from this.
- Happen with or without Vesicoureteral reflux (VUR) (urine flowing back to the kidneys).
- Happen on both sides, from both kidneys (bilateral ureterocele).
Ureteroceles are most often found in children aged 2 or younger. Sometimes it is found older children or adults.
What are some complications of a ureterocele?
The main problem with ureterocele is kidney damage and kidney infection. Urine blockage may damage the developing kidneys and reduce their ability to filter.
Reflux of urine backward to the kidney is also common, especially when there are two ureters in one kidney. This is because the ureterocele distorts the normal one-way valve between the ureter and bladder. Reflux into the opposite kidney may happen. There is also a small risk for kidney stones. In rare cases, ureterocele in girls can protrude outside the urethra and be visible as a balloon.
What are the symptoms of a Ureterocele?
Usually, there are no symptoms. If there are signs, they can be:
How is a Ureterocele Diagnosed?
Often, ureteroceles can be seen during maternal ultrasounds before the birth of a child. Still, they may not be diagnosed until a child is checked for another problem, like a urinary tract infection.
Ultrasound is the first imaging test used to find this condition. Other imaging studies may be done to help understand what’s happening, and for treatment. For an infant or small child, the following tests may be done:
- A voiding cystourethrogram (VCUG) may be done to see the bladder in action. This is a series of X-rays of the bladder and lower urinary tract taken with a special dye. First, a catheter is inserted into the urethra to fill the bladder with a water-based dye. It is removed. Then several X-rays are taken as the patient empties the bladder. These images allow radiologists to find problems in the flow of urine through the body.
- When a ureterocele has been found, it is also important to evaluate the kidneys for damage and evidence for blockage to urine flow across the ureterocele. A nuclear renal scan will provide ample information in this regard.
- In cases where the relevant anatomy is not clear, an MRI test may also be done. This will allow the surgeon to better prepare for surgery (if necessary).
How is a Ureterocele Treated?
The timing and type of treatment used are based on a few things:
- The age and health of the patient
- Whether or not the kidney is affected
- Whether or not VUR is present
Sometimes, more than one procedure is needed. Sometimes, observation (no treatment) may be recommended.
The following are treatment options:
With this treatment, the ureterocele is punctured and decompressed. To do this a cystoscope (a thin tube with camera and light on the end) is used. It usually takes 15 to 30 minutes and can be done without an overnight stay in the hospital.
This treatment doesn't use a large incision. But, if the ureterocele wall is thick, it may not work. If it doesn't work, an open operation may be needed.
Also, there is a slight risk of causing an obstructive flap valve. This would make it difficult to urinate. This treatment works best when the ureterocele is within the bladder (orthotopic).
Upper Pole Nephrectomy
In some cases, the upper half of the kidney does not function from a ureterocele. If there is no urine reflux in the second ureter, the damaged part of the kidney may be removed. Often, this operation is done either through a small cut under the ribs or laparoscopically.
If the entire kidney does not work because of the ureterocele, it must be removed. Usually, this can be done laparoscopically. Sometimes a small incision is needed.
Removal of the Ureterocele and Ureteral Reimplantation
If the ureterocele must be removed, then an operation is done. For this surgery, the bladder is opened, the ureterocele is removed, the floor of the bladder and bladder neck are rebuilt, and the ureteral flap valve recreated to prevent urine from flowing backward to the kidney.
The operation is done with a small incision in the lower abdomen. It is a complex surgery, but it is successful 90-95% of the time.
Ureteropyelostomy or Upper-to-Lower Ureteroureterostomy
If the upper part of the ureter works well and there is no reflux in the lower part ureter, one option is to connect the obstructed part to the non-obstructed part of the ureter or kidney. The operation is done with a small incision in the lower abdomen. The success rate is 95%.