Megaureter

What is a megaureter?

The ureters are part of your urinary system. They’re two thin tubes that carry urine (pee) from your kidneys to your urinary bladder. In most people, each ureter is about 9 inches long and 1/4-inch wide. But a megaureter is an enlarged ureter. It’s greater than 3/8 of an inch wide.

Megaureters are typically congenital (appear at birth). Healthcare providers usually discover megaureters while conducting prenatal (before birth) imaging tests. Without treatment, a serious megaureter can damage your child’s urinary system.

What are the types of megaureter?

There are two main types of megaureters:

• Refluxing megaureter. A refluxing megaureter causes pee to flow back up your ureter to your bladder. This backflow (vesicoureteral reflux) causes your ureter to expand.
• Primary obstructed megaureter. In a primary obstructed megaureter, your ureter is too narrow where it enters your bladder. This causes a blockage of the urine flow.

There are also combinations of the two main types:

• Primary non-obstructed, non-refluxing megaureter. This occurs when there isn’t backflow or an obstruction.
• Refluxing obstructed megaureter. This occurs when there’s backflow and an obstruction. It’s rare.

Secondary megaureters are another class of megaureters. They typically develop as a result of other conditions, including:

• Blockage in your urethra.
• The absence of abdominal muscles at birth (prune belly syndrome).
• Damage to the nerves that control your bladder (neurogenic bladder).

How common is a megaureter?

Healthcare providers and medical researchers aren’t sure how often megaureters occur each year. But they consider megaureters a relatively rare condition that typically occurs during fetal development.

What are the symptoms of a megaureter?

Megaureters don’t usually cause symptoms. Healthcare providers usually find them during prenatal imaging tests. But when symptoms occur in your child, they may include:

• Pain in their side (flank).
• Blood in their pee (hematuria).
• Urinary tract infection (UTI).
• Fever.
• Loss of bladder control (urinary incontinence).

If your child has symptoms, they may vary from others’ symptoms, including how much discomfort they may feel.

What is the cause of a megaureter?

Megaureters usually occur during fetal development. As a fetus develops, the ureter usually consists of a layer of muscle tissue. But sometimes, a stiff, fibrous tissue develops in a section of the ureter instead. The fibrous tissue prevents the wavelike muscle contractions that move pee toward the bladder (peristalsis).

Megaureters can also develop if a blockage stops pee from entering the bladder. Pee starts flowing back toward the kidney, which widens the ureter. Blockages may occur when the bottom end of the ureter that connects to the bladder doesn’t develop properly (ureterocele).

Who do megaureters affect?

Any infant or fetus can have a megaureter. However, megaureters are about four times more common in people assigned male at birth (AMAB).

What are the complications of a megaureter?

Without treatment, megaureters can cause UTIs and kidney damage.

How are megaureters diagnosed?

Healthcare providers typically diagnose a megaureter during a prenatal ultrasound (sonogram). Ultrasounds use high-frequency sound waves to form a picture of the fetus, including the kidney, ureter and bladder structures.

After birth, your child may have megaureter symptoms, including frequent UTIs. Your child’s pediatrician will perform a physical examination. If they suspect your child has a megaureter, they may order additional testing, including:

• Voiding cystourethrogram (VCUG). A VCUG is a type of X-ray. A healthcare provider will insert a tube (catheter) into your child’s urethra and drip a contrast dye through the tube. An X-ray can trace the dye to see if it remains in the bladder or travels up the ureter.
• Kidney ultrasound. A kidney (renal) ultrasound is a specific type of ultrasound that uses sound waves to look at your child’s kidneys and urinary bladder.
• Renal scan. During a renal scan, a healthcare provider injects a small amount of radioactive material (radiotracer) into your child’s vein. Your child will then enter a scanner, which locates the radiotracer and forms a picture on a computer screen to see if there’s blockage around your kidneys.
• Electrolyte panel. An electrolyte panel is a type of blood test that checks your child’s electrolyte levles. High levels of certain electrolytes may indicate that your child’s kidneys aren’t working normally.
• Urinalysis. A provider will send a pee sample to a lab, where technicians will examine it for signs of a UTI.

How do you treat a megaureter?

Megaureter treatment depends on your child’s age, symptoms and overall health. Many children don’t require major intervention and outgrow a megaureter over time. So, your child’s healthcare provider may recommend a “watch-and-wait” approach, which may include:

• Regular ultrasounds to make sure their kidneys are growing normally.
• Antibiotics to reduce the chance of developing UTIs.

If the megaureter doesn’t get better within the first year of your child’s life, increases in size (dilates), causes repeated UTIs or affects kidney function, it may require surgery. Megaureter surgical options include:

• Ureterostomy. During a ureterostomy, a surgeon redirects your child’s ureter to a new opening (stoma) in their abdomen. Pee bypasses their bladder and drains directly into their diaper. After their ureter and kidney go back to a normal size, the surgeon connects their ureter to their bladder.
• Pyeloplasty. During a pyeloplasty, a surgeon fixes or removes the blocked section of your child’s ureter and reconnects it.

What are the risks or complications of megaureter surgery?

Megaureter surgery poses many of the same risks as any other operation, including:

• Anesthesia risks.
• Bacterial infection.
• Heavy bleeding.
• Scarring/blockage.
• Hernia.
• Blood clots.
• The procedure doesn’t fix the problem, so your child needs additional surgery.

Rarely, there may also be a risk of damage to the areas surrounding the ureter, including blood vessels or the bladder.

How soon after treatment will my child feel better?

If your child needs surgery to fix a megaureter, they’ll typically recover after a few weeks. A healthcare provider will give you a better idea of what to expect according to your child’s specific prognosis.

Can a megaureter be prevented?

There isn’t any known way to prevent a megaureter. Healthcare providers and medical researchers need more information on a megaureter’s exact causes, including whether or not it’s genetic.

What can I expect if my child has a megaureter?

In most cases, if a prenatal imaging test reveals a megaureter, the megaureter gets better gradually without surgery. Your child will need regular imaging tests to monitor the megaureter, and they may need regular antibiotics to prevent UTIs.

If the megaureter doesn’t get better on its own, your child may need surgery.

What is the outlook for a megaureter?

In general, the long-term outlook for a megaureter is good. In many cases, a megaureter will improve on its own without intervention. The success rates of surgical treatments for a megaureter are high.

When should I take my child to a healthcare provider?

If your child has a megaureter, they may need regular imaging tests to evaluate their ureters and kidneys. Be sure to take your child to every appointment. If you have to cancel, be sure to reschedule.

When should I go to the ER?

Go to the nearest emergency room if your child has UTI symptoms and develops:

• Back pain.
• A fever.
• Nausea and vomiting.

What questions should I ask a healthcare provider?

You may want to ask your provider:

• How do you know my child has a megaureter?
• What type of megaureter does my child have?
• Does my child need treatment?
• What kind of megaureter treatment do you recommend?
• How do I make my child comfortable if they have a megaureter?

A note from Cleveland Clinic

It can be difficult and overwhelming to hear that there may be something wrong during a prenatal imaging test. But the good news is that if a healthcare provider discovers a megaureter before birth, it usually gets better without surgery. If your child needs surgery, the success rate is high. As your child grows, they may need regular imaging tests and antibiotics to prevent urinary tract infections. If you have any questions, talk to a healthcare provider.