Ureterocele

What is Ureterocele?

A ureterocele is a birth defect where the tube that carries urine from the kidney to the bladder, also known as the ureter, becomes swollen or enlarged. Most often it affects the upper section of a duplicate kidney, something that happens in 80% of cases.

Back in 1927, a scientist named Chwalla suggested that ureteroceles are caused by a membrane, known as the Chwalla membrane that blocks the ureter. This membrane, which is supposed to dissolve, is made up of tissue from the urinary and genital system. But more recent studies suggest that the condition may be linked with other problems in the urinary system caused during the development of the embryos.

Ureteroceles can be classified into two types, intravesical (inside the bladder) and extravesical (outside the bladder). The intravesical type includes stenotic ureteroceles and nonobstructed, large ureteric openings, generally found in non-duplicate kidney systems. On the other hand, extravesical or ectopic ureteroceles include various types and are more often found in duplicated kidney systems. Around 60% of ureteroceles that occur with duplicate kidneys are of this type.

Intravesical ureteroceles are usually found in people with single kidneys. In some cases, the ureter’s opening is relatively small, leading to a blockage and resulting in a swelling of the ureter. This might affect the function of a duplicated system’s kidney. But in about 5% of cases, the opening of the ureter is large and unrestricted.

Extravesical ureteroceles, also known as ectopic ureteroceles, tend to be linked with complete kidney duplications. Where they insert in the body can vary, but generally, it follows the path of the ureter. In some cases, the ureter’s opening and the bladder’s neck overlap, which can cause a blockage. In completely duplicated systems, the obstruction can cause the ureter or the upper part of the kidney to swell.

There is also a less common type, known as a cecoureterocele, which forms where the ureter opens within the bladder but has a long extension into the bladder. This extension fills up when you pee, and it can block urine flow. Whether it’s problematic depends on whether the opening is restricted or open – if it’s restricted, it only drains from the kidney, while if it’s open, it fills from the bladder.

What Causes Ureterocele?

During the fourth week of pregnancy, the baby-to-be’s kidneys start to form. This begins around 32 days after conception when a structure known as the “ureteral bud” sprouts from another part of the baby’s body called the “mesonephric duct”. It then travels towards the “metanephric blastema” to initiate the process of kidney formation, normally resulting in one kidney drainpipe or “renal pelvis” and normal divisions that collect urine, known as “calyces”.

Sometimes, the ureteral bud splits before reaching the metanephric blastema, leading to what’s called “partial ureteral duplication”. Just like a fork in the road determines which path you take, the location of this split determines the final shape of the urine drainpipes or “ureters”. This results in a kidney with both an upper and lower part, each having two separate ureters starting points, which eventually merge before entering the bladder, ending in one opening on each side of the bladder.

“Complete duplication” takes place if two separate ureteral buds sprout from the mesonephric duct and each connects with the metanephric blastema. An additional ureteral bud can sometimes develop, resulting in a completely doubled set of ureters and kidneys. While this usually follows a known pattern, there have been a few rare exceptions reported.

Some families have a tendency towards developing “ureteroceles”, balloon-like swellings at the end of the ureters, which suggests that genetics might play a role. Ureteroceles are usually unique defects and aren’t associated with other birth abnormalities of the urinary system.

There are different explanations for why ureteroceles form. One theory is that if a membrane called the “Chwalla membrane” doesn’t break down correctly, it can block the ureteral bud and cause the formation of a ureterocele. Other mechanisms are also likely involved, especially for ureteroceles that occur in abnormal locations. For instance, strange development of certain muscle tissue in the bladder can create a spacer, potentially leading to a ureterocele. Also, if the ureteral bud joins the bladder at a slower pace than normal, it can impact the development of the ureteral opening and the part of the ureter in the bladder wall, potentially resulting in a ureterocele.

Risk Factors and Frequency for Ureterocele

Ureteroceles, which are unusual congenital anomalies, affect women 4 to 6 times more than men. This might be due to women having more duplicated systems. The condition is quite rare, affecting 1 in 500 to 4000 people. It’s also interesting to note that ureteroceles are more common on the left side and are more prevalent among white individuals.

Ureteroceles found in a single, non-duplicated kidney are usually intravesical (inside the bladder) rather than ectopic (out of place), and these are more common in men, making up about 66% of these cases. When it comes to ureteroceles in women, an overwhelming 95% of them occur in duplicated systems. For men, only about 34% present this condition in a duplicated system.

• About 10% of all ureteroceles occur in both renal units (they’re bilateral).
• Out of these bilateral cases, around 80% are associated with completely duplicated urinary systems, meaning each kidney has 2 separate ureters.
• The remaining 20% of ureteroceles are sporadic anomalies occurring without any associated duplicated urinary system.

Signs and Symptoms of Ureterocele

Ureteroceles can have a significant negative impact on a person’s health and quality of life if they go undetected or untreated. That’s why it’s crucial to take a detailed medical history when diagnosing and evaluating ureteroceles. One should also look into family history, as this could increase the risk.

In young children and babies (neonates), common symptoms of ureteroceles include poor growth, repetitive or early urinary tract infections (UTIs), and urosepsis which is a serious infection that has spread throughout the body. Urinary symptoms could occur if a ureterocele that has shifted (ectopic ureterocele) is blocking the urethra. In rare cases, a large ureterocele might appear as a vaginal mass in females. Other possible symptoms in children include:

• Incontinence
• Urolithiasis (stone formation in the urinary tract)
• Unexplained abdominal mass
• Urinary outlet obstruction
• Urethral or vaginal prolapse

In adults, the condition may not show any symptoms or it may lead to flank pain, urolithiasis, or recurrent UTIs. Less commonly, a ureterocele might cause chronic abdominal pain.

The assessment and management of ureteroceles typically fall into two categories: before birth (antenatal) and after birth (postnatal). Routine ultrasound scans done at 12-14 weeks and again at 20 weeks of pregnancy can often identify ureteroceles. However, the most accurate evaluation of the baby’s urinary tract usually happens at around 28 weeks of pregnancy. In about 2% of pre-birth cases where there is excessive fluid in the kidneys (prenatal hydronephrosis), a ureterocele is the cause.

After a baby is born, symptoms like pain, UTIs (most common), or presence of a bulging fluid-filled cyst related to the condition may occur. Hydronephrosis along with abdominal pain and urinary stones are other common symptoms. It is crucial to monitor a child’s weight and height on growth charts and conduct routine urine tests, as recurring UTIs or sepsis can negatively impact the child’s growth and development.

For adults, ureteroceles are usually discovered incidentally during imaging studies for other health issues. Adult ureteroceles typically do not duplicate, are within the urinary bladder, and involve a single system.

Important vital signs like fever and high blood pressure can help identify the severity of the condition. Fever might suggest a severe infection and risk of sepsis, while high blood pressure could be a long-term complication due to kidney scarring from pyelonephritis, especially in children under 4 years old.

During a physical check-up, tenderness, particularly in the side area of the lower back (flank), might be discovered through abdominal palpation. Occasionally a mass could be felt. If a mass is found in the loin area (side of the lower back), it could mean a kidney is not working or renal moiety (part of a duplex kidney). In rare cases, a protruding ureterocele might appear as a vaginal mass in females.

Testing for Ureterocele

Getting the right diagnosis and treatment for ureteroceles involves several different tests. These include blood and urine tests and different types of imaging studies. These tests are important for not only detecting the condition, but also for understanding how severe it is, predicting any complications, and deciding on the best course of treatment. Most of the time, ureteroceles get found before a child turns 3 years old, and more and more are being diagnosed before birth.

Let’s start with the lab tests. Your doctor is likely to order a complete blood count, some tests to check how your kidneys are working, and a C-reactive protein test – an indicator of inflammation in the body. If your kidneys aren’t working as well as they should be, this can signal a blockage. High levels of inflammation in the body could indicate a serious infection.

One simple, painless way to check for urinary tract infections (UTIs) is a urine dipstick test. This can detect substances in the urine that are common in UTIs. If this test comes back positive, your doctor will likely want to conduct more thorough urine tests to identify the specific bacteria causing the infection and choose the best treatment.

Ultrasound is often used to diagnose ureteroceles. This machine uses sound waves to create a picture of the inside of your body. In this case, it’s able to create an image of a round mass in the bladder, which is typically an ureterocele. However, if the bladder is too full or empty, it can be hard to see. So, usually, additional tests are needed.

Two common types of imaging studies for ureteroceles are antenatal and postnatal assessments. Antenatal assessments are done before birth and can usually find significant ureteroceles. Following the antenatal detection of ureteroceles, appropriate management is initiated. If prenatal ultrasound identifies a duplicated system with hydronephrosis involving the upper pole, a ureterocele is found 70% of the time.

If your physician suspects hydronephrosis, which means that your kidneys have swelled due to a buildup of urine, then they will likely order another ultrasound and a mercaptoacetyltriglycine (MAG3) renogram when your baby is about 3 months old. This gives time for your baby’s kidneys to mature so the test results are reliable. A MAG3 renogram helps spot any blockages and can show how well your kidneys are working.

A useful tool in assessing ureteroceles and related urinary tract anomalies, particularly in complex duplication patterns and when assessing the function of a dysplastic upper pole, is a magnetic resonance urography (MRU). Plus, it avoids radiation exposure, making it increasingly the go-to diagnostic tool for young girls who have urinary incontinence that’s thought to be related to a ureterocele. However, an MRU can be expensive, and it might require that your little one be sedated or given general anesthesia.

For cases of ureteroceles being managed conservatively, the typical recommendation is for ultrasound scans every 6 months and MAG3 scans every year or more frequently if ultrasound results indicate worsening conditions. Following surgery on a ureterocele, ultrasound and cystourethrogram scans are typically repeated to assess the results of the procedure.

Keep in mind that while it’s not always necessary, cystoscopy (where a doctor inspects the bladder with a thin, lighted instrument) can be helpful in diagnosing and managing specific cases. It can offer more details about ureteroceles that aren’t clear through diagnostic imaging and might even reveal a hidden ectopic ureteral orifice, leading to a more comprehensive understanding of what’s going on in the body and helping decide on the most appropriate treatment.

Treatment Options for Ureterocele

Ureteroceles, or swellings in the tube that carries urine from your kidneys to your bladder, might require a range of treatments, and the choice depends on several factors. These factors include the patient’s age, the severity of the ureterocele, the health of the other kidney, whether there is backward flow of urine, and the type of ureterocele.

The main goal of any treatment is to figure out, first, if treatment is needed, and if so, what that treatment should be and when it should be given. The ultimate goal is to maintain kidney function, avoid infections, manage symptoms, and improve quality of life. In cases where a patient has two drainage tubes from each kidney (duplex urinary system), one of the important goals is to maintain the function of the upper drainage tube. This is often done by early surgical incision (cutting the skin) while also use antibiotics for backward flow of urine until it gets better or a definitive treatment is identified.

For patients with ureteroceles who are not showing symptoms, who have preserved kidney function, and no backward flow of urine, it might be better not to intervene. In these cases, a scan called a MAG3 renogram is conducted to ensure there are no obstructions affecting kidney function.

After birth, the management of ureteroceles may be different depending on the individual circumstances. Sometimes, doctors may just monitor the condition if the baby’s symptoms are well-controlled, and the kidney function is preserved, especially in cases where there are larger ureteroceles.

There are also several surgical options for ureterocele treatment. One common technique involves making a small incision in the ureterocele using an endoscope, basically a small tube with a camera. This eases symptoms and prevents urinary tract infections while protecting the kidney. Other techniques may involve repositioning the ureter or removing a part of the kidney. The choice of technique usually depends on the individual situation and the associated symptoms or risks, as well as the surgeon’s experience and the preferred procedure in each medical center.

The treatment for a condition called oligohydramnios, where there is not enough amniotic fluid around the baby during pregnancy, may be different for cases with severe prenatal hydronephrosis, peripheral swelling due to ureteroceles. If a baby born with severe bilateral hydronephrosis may be at risk for breathing problems and kidney issues, medical staff may need to monitor the pregnancy closely, considering interventions to optimize the baby’s lung growth and overall health. However, such interventions are still considered investigational and should only be performed in special care centers after fully discussing the potential risks.

To summarize, in managing ureteroceles surgically, it’s crucial to evaluate several factors, including symptoms, patient age at the time of diagnosis, contralateral kidney function, whether the ureterocele is located inside or outside the bladder, and whether there is renal duplication. A condition called vesicoureteral reflux, where the urine flows backwards from the bladder, will also be checked.

What else can Ureterocele be?

When diagnosing ureteroceles, it’s necessary to think about other conditions that may have similar symptoms. These could include:

• “Hutch” or periurethral bladder diverticulum
• Cystitis (inflammation of the bladder)
• Functional abdominal pain
• Nephrolithiasis (kidney stones)
• Pelvic organ prolapse (when a pelvic organ drops from its normal place)
• Pseudoureterocele (a false ureterocele)
• Pyelonephritis (kidney infection)
• Urinary tract infection (UTI)
• Vesicoureteral reflux (backward flow of urine from bladder to kidneys)

What to expect with Ureterocele

The outcome of ureteroceles (a condition that involves swelling in one of the tubes that carries urine from the kidney to the bladder) depends on several factors. These factors include how severe the condition is, how complex it is, and when it is diagnosed. In very severe cases or when the condition is not diagnosed in a timely manner, there can be significant risks. These might include potential loss of kidney function or even life-threatening outcomes if an uncontrolled infection, or ‘sepsis,’ occurs.

On the other hand, if ureteroceles are identified and treated promptly, excellent results can be expected. Recognizing the condition and taking the right steps early on is extremely important to ensure the best possible outcome for individuals with ureteroceles.

Possible Complications When Diagnosed with Ureterocele

Ureteroceles, a condition related to the urinary tract, can result in many complications. These complications largely depend on the condition’s severity and how it’s treated. Several of these potential issues include:

• Hydronephrosis: In severe cases, untreated ureteroceles can cause the kidney to enlarge due to urine buildup.
• Hypertension: Ongoing kidney problems can result in high blood pressure, which might require treatment.
• Lower urinary tract voiding dysfunction: These could be symptoms like incontinence, frequent urination or sudden urges to urinate. This problem could be temporary, occasional, or constant, particularly with certain types of ureteroceles.
• Obstruction: Ureteroceles can cause either partial or total urinary tract obstructions, which can hinder urine flow from the kidney to the bladder.
• Pain: Ureteroceles may lead to pain in the stomach or side, especially if symptoms are present.
• Psychosocial and developmental issues in children: Kids who have regular infections, medical procedures, or surgical interventions linked to ureteroceles could experience social and developmental problems.
• Recurrent UTIs: Ureteroceles could make individuals more likely to experience regular urinary tract infections because of urine reflux or urinary stasis within the ureterocele. This is particularly true for children.
• Renal function impairment: Long-term obstructions or recurrent infections can cause kidney damage and reduced renal function, particularly if not managed well.
• Renal scarring: Chronic or severe infections can lead to scarring of kidney tissue, which could potentially affect kidney function.
• Sepsis: In severe cases, untreated or recurrent UTIs linked to ureteroceles could result in sepsis, a life-threatening condition.
• Stones: This condition can lead to stone formation in the dilated ureterocele or a kidney stone getting stuck in the ureterocele cavity.
• Vesicoureteral reflux: This can occur as a complication following surgery on the ureterocele, leading to recurrent infections and reduced kidney growth or function.

It’s crucial to diagnose and treat ureteroceles promptly to avoid or reduce these potential complications and protect kidney function and overall health. Specific complications can vary based on personal factors and the type of ureterocele.

Preventing Ureterocele

Screening during pregnancy (antenatal screening) is a crucial step in identifying any ureteroceles—abnormal swellings in the tubes that carry urine from the kidneys to the bladder—early on. Parents must be well-informed about what these mean for the child’s health. Moreover, they should be familiar with early warning signs of complications such as urinary tract infections (UTIs) or kidney infections (pyelonephritis), and any pain, so they immediately seek medical help when needed.

This screening is also an opportunity to prepare parents for what their infant might need after birth, which may include surgery. Parents will need to learn to spot early signs of complications, like pain and infections leading to UTIs or kidney infections, and quickly get medical attention for their child.

Knowing what to look out for and acting quickly can immensely help in ensuring the child’s health and avoid further complications associated with ureteroceles.

When explaining ureteroceles to parents, it’s crucial to be clear about the possibility of developmental delays and the potential need for drugs to prevent infection (prophylactic antibiotics). Parents should keep an eye on their child’s milestones and keep a growth chart as a record. Learning about how to manage ureteroceles, particularly how to support their child’s bladder through urotherapy, is vital.

Urotherapy involves education about the bladder’s normal workings and the importance of regular urination, especially if the child is being treated conservatively or is awaiting further treatment. This knowledge helps parents know how to aid their child’s bladder health, contributing to the overall success of the treatment.

In some cases, it may be necessary for the child to take antibiotics routinely to prevent infection. Yet, parents should be aware of the fine balance between the risk of antibiotic resistance and the positives of preventing infection and sepsis (a life-threatening reaction to infection). They should also have practical skills such as collecting urine samples when required and checking the child’s bowel movements. These skills, along with informed decision-making, are key to caring for a child with ureteroceles. This ensures their health and well-being while minimizing any possible risks.