Megaureter - Types, Clinical Features, Diagnosis, and Treatment Measures

Introduction:

The urinary tract is almost like a human plumbing system. It consists of two kidneys, two ureters, a urinary bladder, and a urethra. Ureters are tubes that connect the kidneys to the urinary bladder. Water and salts travel through the ureters to the bladder to be stored and are later excreted via the urethra. Most infants are born with entirely normal ureters, while some have wider ureters than others.

What Is a Megaureter?

Megaureter means a larger ureter in layman's terms. Ureters are known to be megaureters when they are wider than six or seven millimeters. This medical anomaly can cause problems such as obstructed urine flow and infections. If left untreated, this can lead to serious kidney problems. They are usually found during prenatal imaging. Megaureters are not a very common condition, but they are found four times more in males than in females. Megaureters can be caused by a problem related to the ureter itself, called a primary megaureter. In some instances, the megaureter results from the blockage of the urinary bladder, known as the secondary megaureter.

The following are the types of megaureters:

1. Primary Obstructed Megaureter: In this type of megaureter, the ureter near the bladder is constricted, which leads to the blockage of the ureter. This leads to the widening of the ureter further up. This condition can damage the kidney as time progresses, and medical care is required to avoid further severe complications related to the kidney.

2. Refluxing Megaureters: This type of megaureter is commonly seen in newborn males and is characterized by the backflow of urine from the urinary bladder towards the kidney via the ureter. This is not a normal phenomenon, as urine is not supposed to flow back from the bladder. This leads to the abnormal widening of the ureter. This is a sign of vesicoureteral reflux. Refluxing megaureters usually return to normal during the first year of life, but surgical treatments are required if it does not. Refluxing megaureters are often linked to other health problems like megacystis megaureter syndrome. Here, the reflux of urine along the ureter leads to improper urine drainage and hence leads to the swelling of the bladder.

3. Nonobstructive, Non-refluxing Megaureters: Unlike the previously mentioned types, this type is not associated with blockage or urinary reflux along the ureter. It usually gets back to normal without any treatment.

4. Obstructed Refluxing Megaureters: This type of megaureter is a combination of obstructive and refluxing megaureters. It is known to be serious as it leads to extreme widening of the ureter. If left untreated, it can cause severe kidney complications. People with this type of megaureter are often affected by urinary tract infections (UTIs).

5. Secondary Megaureters: This type occurs when the problem is not with the ureter itself. Instead, megaureter is a manifestation of other health conditions such as,

• Prune belly syndrome.

• Neurogenic bladder.

• Posterior urethral valves (blocks in the male urethra).

What Are the Causes of a Megaureter?

Megaureter can develop from various causes.

1. The ureter consists of flexible, muscular tissue. However, some children are born with rigid, inflexible tissue at the base of one or both ureters. This lack of flexibility impedes urine movement into the bladder, leading to urine backup and ureter stretching.

2. In other cases, megaureter results from urinary dysfunction. Urine intended to flow from the kidney to the bladder may reverse its course, moving the ureter toward the kidney. This condition, known as vesicoureteral reflux, often varies in severity.

What Are the Signs and Symptoms of a Megaureter?

Following are the common signs and symptoms associated with megaureter:

• Frequent urinary tract infections.

• Fever.

• Nausea or vomiting.

• Back pain.

• Untreated megaureters can cause severe kidney problems.

How to Diagnose a Megaureter?

When a child experiences frequent urinary tract infections or any of the symptoms mentioned above, your general physician or a urologist may ask for the following tests to make an exact diagnosis.

Ultrasound scans are images produced by sound waves that bounce off internal organs. They are painless procedures that can help diagnose widened ureters in children. Ultrasound is performed during pregnancy to check the progress of the pregnancy, and many babies with congenital megaureters are usually diagnosed when they are in the uterus during regular ultrasound sessions.

Voiding Cystourethrogram (VCUG): This test is a specific type of x-ray to diagnose vesicoureteral reflux. Here, a dye is loaded into a catheter and is injected into the urinary bladder via the urethra. An x-ray is taken to diagnose if there is any reflux of dye from the urinary bladder into the ureter.

Diuretic Renal Scans: Diuretic renal scans are done to diagnose any blocks in the ureter and can also assess the kidneys' overall performance by injecting a radioactive liquid into the veins that reach the kidneys.

Magnetic Resonance of the Urinary Tract (Mr-U): This method provides accurate and more precise images of the kidneys and ureters than diuretic renal scans and ultrasound scans. However, this method is not used in small children as it might require general anesthesia or sedation.

What Is the Reason for Treating Megaureters?

Irrespective of whether megaureter results from reflux or obstruction, treatment is necessary to prevent urinary tract infections and potential kidney harm. Both reflux and obstruction pose risks of kidney damage, particularly when coupled with urinary tract infections. Prophylactic antibiotics may be prescribed due to the heightened infection risk, and surgery may also be necessary.

How to Treat Megaureters?

After being diagnosed with megaureters, your doctor may opt for one of the following treatment options,

• In most cases, megaureters resolve without treatment or surgery before the baby reaches its first age.

• The doctor might prescribe antibiotics to prevent frequent urinary tract infections.

• In some cases, when megaureters do not resolve within the first year of life, the doctor might perform open surgery. Here, a well-experienced surgeon who can deal with neonates should be assigned, as extra care is required. During this surgery, the doctor removes the ureter, trims it, removes any blocks, and places it back into place.

• Minimally invasive methods can also be used, such as balloon methods, where a balloon is used to stretch the narrow part of the ureter. This can also be done to remove blocks.

What Occurs After Treatment for a Megaureter?

For megaureters without reflux or obstruction, spontaneous resolution often occurs during childhood. Prophylactic antibiotics may continue until after potty training, with periodic ultrasounds tracking kidney growth and the megaureter. Once resolved, further follow-up or antibiotics are unnecessary.

In cases requiring surgery for megaureters, prophylactic antibiotics are typically prescribed for a period post-surgery, with serial ultrasounds conducted to monitor kidney health. Surgery is highly effective in alleviating the obstruction. Even with surgery, the majority of children with megaureters lead normal lives.

What Are the Complications Associated With Megaureter Surgery?

Megaureter surgery carries similar risks to other surgical procedures, including:

• Anesthesia complications.

• Bacterial infection.

• Excessive bleeding.

• Formation of scars or blockages.

• Hernias.

• Formation of blood clots.

In some situations, the procedure may not completely resolve the issue, thus requiring further surgery for the child. In rare cases, there is a risk of injury to nearby areas, such as blood vessels or the bladder, during the surgery.

Conclusion:

There is no way to prevent megaureter. However, a proper diagnosis can be made during regular checkups during pregnancy, and the condition can be treated as soon as possible to avoid severe kidney problems. In most cases, megaureters cure themselves before one year of age; therefore, regular visits to the urologist and frequent ultrasounds must be taken to keep the condition under control.