Congenital Ureteric Anomaly

Congenital ureteric anomalies are birth defects affecting the tubes that carry urine from the kidneys to the bladder. These conditions can lead to various complications, including infections, blockages, and kidney damage, but many can be successfully treated with modern surgical techniques.

Table of contents

• What is a congenital ureteric anomaly?
• Types of ureteric anomalies
• Signs and symptoms
• What causes these conditions?
• How are ureteric anomalies diagnosed?
• Possible complications
• Treatment options

What is a congenital ureteric anomaly?

A congenital ureteric anomaly is a birth defect that affects the ureters, which are the tubes of muscle that carry urine from your kidneys to your bladder. “Congenital” means the condition is present at birth, though it may not be discovered until later in childhood or even adulthood^[1].

Most people have two ureters, one connecting each kidney to the bladder. These tubes play an important role in the urinary system by transporting filtered waste in the form of urine from the kidneys to the bladder, where it is stored until it leaves the body^[1]. When ureters form abnormally during fetal development, they may not function properly, which can affect kidney health and urinary function.

Ureteric anomalies frequently occur alongside kidney abnormalities but may also occur independently^[2]. These conditions are part of a larger group of birth defects called congenital anomalies of the kidney and urinary tract (CAKUT), which represent one of the most common types of birth defects affecting newborns^[4].

• Ureters
• Kidneys
• Bladder

Types of ureteric anomalies

Several different types of abnormalities can affect the ureters. Understanding these variations helps in recognizing how they might impact urinary function.

Ectopic ureteral orifices occur when the opening of the ureter is in the wrong position. Instead of connecting normally to the bladder, the ureter may open on the side of the bladder wall, along the bladder neck, in the urethra, or even in the genital system. In males, this may involve the prostate or seminal vesicle, while in females it may involve the uterus or vagina. The ureter may even open externally^[2]. When the opening is positioned laterally, it frequently leads to urine flowing backward into the ureter, while openings positioned lower down more often cause blockages and urinary leaking^[2].

Ureter duplication anomalies happen when one or both kidneys have two ureters instead of one. This duplication can be partial (incomplete) or complete. In complete duplication, the ureter from the upper part of the kidney opens at a different location than the ureter from the lower part. When problems occur, the lower portion tends to allow urine to flow backward, while the upper portion tends to develop blockages^[2]. Partial duplication rarely causes clinical problems^[2].

Ureteral stenosis refers to narrowing that can occur anywhere along the ureter. The most common location is where the ureter connects to the kidney (called ureteropelvic junction obstruction), and less commonly where it connects to the bladder (called ureterovesical junction obstruction or primary megaureter). These narrowings can lead to infection, blood in the urine, and obstruction. In many cases, the narrowing becomes less severe as the child grows^[2].

Ureterocele is a condition where the lower end of the ureter bulges into the bladder, creating a balloon-like swelling with a very narrow opening. This can cause progressive widening of the ureter, swelling of the kidney, infections, occasional stone formation, and impaired kidney function^[2].

Retrocaval ureter is a rare condition caused by abnormal development of the large vein that runs along the spine (the vena cava). This allows the vein to form in front of the ureter, typically on the right side, which can cause blockage of the ureter^[2].

Signs and symptoms

The presence of ureteric anomalies may be suggested before birth through routine prenatal ultrasound, which might detect urinary tract abnormalities such as swelling of the kidney^[2]. In newborns or children, these conditions are occasionally detected by physical examination, such as finding an external opening where the ureter exits or feeling an abnormal mass^[2].

Healthcare providers should suspect ureteric anomalies in children who experience an episode of kidney infection or recurring urinary tract infections. In girls, persistent urinary leaking (inability to hold urine) may be a sign, while in boys, recurrent episodes of testicular inflammation may suggest an anomaly^[2].

Common symptoms that may indicate a ureteric anomaly include recurring urinary tract infections, often with pain or burning during urination. Urinary leaking is another significant symptom. Some children may develop swollen kidneys because the kidneys cannot empty properly. Urine may flow backward from the bladder into the ureters or kidneys^[11].

While a ureteric anomaly itself typically does not cause pain, it may lead to other conditions that have painful symptoms. These can include inflammation of various parts of the reproductive system in males, urinary tract infections, and pain during ejaculation^[11].

What causes these conditions?

The causes of congenital ureteric anomalies are complex and not fully understood. Healthcare providers believe that a combination of genetic and environmental factors contribute to the formation of urinary tract abnormalities during fetal development^[4].

The genetic factors involved in most cases remain unknown. However, when ureteric anomalies occur as part of a syndrome affecting multiple body systems, they are caused by changes in specific genes associated with that syndrome. Changes in these same genes can sometimes underlie isolated cases of ureteric anomalies as well^[4].

Research shows that the same genetic change can lead to different types of urinary tract abnormalities, even among members of the same family. This suggests that additional changes in other genes help determine how the condition develops and how severe it becomes^[4].

Environmental factors may also influence the development of ureteric anomalies. The risk is higher in babies whose mothers had diabetes during pregnancy or took certain medications that can harm the kidneys, such as some anti-seizure drugs^[4].

Anyone can have a ureteric anomaly at birth, but certain factors may increase the risk. Females are about 10 times more likely to have an ectopic ureter, though the reasons for this are not fully understood. Additionally, having a biological parent with an ectopic ureter increases the risk of having one^[11].

How are ureteric anomalies diagnosed?

Diagnosing ureteric anomalies can be challenging because they share many signs and symptoms with other conditions. When investigating a potential ureteric anomaly, healthcare providers will review the child’s health history, ask about symptoms, inquire about family history of similar conditions, conduct a physical examination, order blood tests to check kidney health, and perform urine tests to check for infection^[11].

Testing typically involves ultrasound imaging of the kidneys, ureters, and bladder both before and after urination. This is followed by a special X-ray test called fluoroscopic voiding cystourethrography, which shows how urine flows through the urinary system^[2].

For certain conditions, such as an ectopic ureter associated with a non-functioning part of the kidney, magnetic resonance urography may be used. This advanced imaging technique can provide detailed pictures of the urinary tract^[2].

Many ureteric anomalies are now being detected before birth through routine prenatal ultrasound examinations. When abnormalities are seen on these scans, more detailed imaging can be performed after the baby is born to determine exactly how the urinary tract is affected^[8].

Possible complications

Ureteric anomalies can lead to several important complications that affect urinary and kidney health. The most common complications include obstruction (blockage of urine flow), backward flow of urine from the bladder into the ureters (vesicoureteral reflux), urinary tract infections, and formation of kidney stones due to urine that does not flow properly^[2].

Urinary leaking is another significant complication, particularly when the ureter connects abnormally to the urethra, the area between the legs, or the vagina^[2].

The abnormalities can result in recurring urinary tract infections or a buildup of urine in the urinary tract, which may damage the kidneys or other structures. In severe cases, these conditions can lead to reduced kidney function and may progress to life-threatening kidney failure^[4].

Congenital anomalies of the kidney and urinary tract are among the most common causes of chronic kidney disease and kidney failure in children^[4].

Treatment options

Ureteric anomalies are treated surgically when they cause problems with urinary function or kidney health^[2]. The type of surgery depends on the specific anomaly and its severity.

For ectopic ureteral orifices, surgery is needed when there is obstruction, urinary leaking, and sometimes when there is backward flow of urine^[2].

For retrocaval ureter causing significant obstruction, surgeons divide the ureter and reconnect it in front of the vein or blood vessel^[2].

When ureter duplication causes obstruction, backward urine flow, or urinary leaking, surgery may be necessary. However, incomplete duplication rarely requires treatment^[2].

For ureteral stenosis, the approach depends on the location. When narrowing occurs at the connection between the kidney and ureter (ureteropelvic junction obstruction), a procedure called pyeloplasty may be performed. This involves removing the blocked segment and reconnecting the ureter. The surgery can be done using traditional open techniques, or with minimally invasive approaches using a laparoscope (a thin tube with a camera) or robotic assistance^[2]. When the narrowing is at the bladder connection (primary megaureter), the ureter may need to be narrowed and reimplanted if swelling increases or infections or blockages occur^[2].

For ureterocele, treatment options include endoscopic surgery performed through the urethra to create an opening, or traditional open surgical repair^[2].

In infants, some procedures like pyeloplasty are often performed with open surgical techniques requiring a small cut along the side of the abdomen. In older children, surgeons may use robotic-assisted laparoscopic techniques, which involve a few tiny incisions. While these minimally invasive procedures take longer to perform, the outcomes are similar to open surgery, and older children and adolescents may recover more quickly^[13].

The timing of surgical treatment depends on the severity of the condition, its impact on quality of life, and the patient’s readiness for surgery^[24].