What is megaureter?

Megaureter (dilated ureter) is an abnormality of one or both of the ureters of a child. Ureters are the tubes that carry urine from the kidneys to the bladder. A megaureter refers to an expanded or widened ureter that does not function normally.

Complications associated with megaureter include reverse flow of urine into the kidneys and pooling of urine inside the ureter that does not drain. These two conditions are called hydronephrosis and vesicoureteral reflux. A child may also develop urinary tract infections.

What causes a megaureter?

A megaureter that is not associated with other problems occurs during fetal development. It occurs when a section of the ureter, which is normally a muscular layer of tissue, is replaced by stiff, fibrous tissue. In the absence of a muscular layer, normal peristalsis (worm-like movement of the ureter that propels urine toward the bladder) cannot occur. Megaureter can occur alone, but usually occurs in combination with other disorders.

What are the symptoms of megaureter?

The condition may occur in varying degree and each child may experience symptoms differently. Symptoms of a megaureter also may resemble other conditions or medical problems. The specialists at the CHOC Urology Center work with patients to ensure the proper diagnosis and treatment.

How is megaureter diagnosed?

The severity of the problem often determines how a diagnosis is made. Often a megaureter is diagnosed by an ultrasound while the child is still in the womb. After birth, some children may have other problems that may suggest the presence of megaureter such as urinary tract infections. This may prompt the child’s doctor to perform further diagnostic tests, which may include the following:

  • Voiding cystourethrogram (VCUG) is a specific X-ray that examines the urinary tract and allows specialists to see a direct image of the bladder and a refluxing ureter, if present.
  • Renal ultrasound uses a transducer (the wand) is passed over the kidney and allows us to determine the size and shape of the kidney, and to detect a mass, kidney stone, cyst or other obstruction or abnormalities.
  • Diuretic renal scan is a diagnostic nuclear imaging technique that is conducted by injecting a radioactive fluid into the vein. The radioactive material is then carried to the kidneys where it gives off signals that can be picked up by cameras. Midway during the procedure, a diuretic medication is given to speed up urine flow through the kidneys. This helps detect any area of blockage in the urinary tract. The total amount of radiation received in this test is less than an x-ray.

What is the treatment for megaureter?

CHOC Urology Center determines each patient’s specific treatment based on:

  • Child’s age, overall health, and medical history
  • Extent of the disorder
  • Child’s tolerance for specific medications, procedures or therapies
  • Expectations for the course of the disorder
  • Family’s opinions or preferences

Patients may require antibiotic therapy as a prophylaxis to prevent future urinary tract infections.

In some cases, medical intervention is not required because the megaureter will resolve on its own over time. If there is a blockage of the urinary tract, however, a megaureter may require surgical intervention. The surgical procedure involves removing the section of the ureter that is abnormal, reducing it and reconnecting the ureter.

What are the tests used by the CHOC Urology Center?

Read our Common Diagnostic Procedures Guide for in-depth information on the tests we use.