What are the other Names for this Condition? (Also known as/Synonyms)

• Alternating Urachal Sinus

What is Alternating Sinus of Urachus? (Definition/Background Information)

• The urachus is a tubular structure that forms during early fetal development. This structure connects the anterior portion (anterior bone) of the urinary bladder to the umbilicus. Usually, the urachus closes by week 12 of gestation, leaving behind a thick fibrous band. However, rarely, some portions of the urachus may not close completely, resulting in a variety of urachal abnormalities
• Alternating Sinus of Urachus occurs when the urachus fails to completely seal at both ends i.e., either at the umbilicus or at the urinary bladder, such that it causes the periodic discharge of infected fluid contents at either ends alternatively. This condition is extremely uncommon
• Even though Alternating Sinus of Urachus is a congenital occurrence; in many cases, it may remain symptomless and thus, may be undiagnosed throughout one’s life. When symptoms develop, they are known to do so frequently in childhood than adulthood
• The signs and symptoms of Alternating Sinus of Urachus often arise due to infection and may include fluid discharge from the umbilicus and abdominal pain. There is an elevated risk for recurrent infections in some cases
• In rare cases, symptomatic Alternating Sinus of Urachus may be surgically resected, either through an open approach or a laparoscopy. The prognosis of children with isolated urachal anomalies (i.e., not associated with any other congenital conditions) is typically good with adequate treatment

There are five forms of congenital urachal remnant abnormalities, and these include:

• Alternating Sinus of Urachus (some experts recognize this as a type of umbilical-urachal sinus)
• Patent urachus
• Umbilical-urachal sinus
• Urachal cyst
• Vesicourachal diverticulum

Among these urachal abnormalities, patent urachus is the only condition that predominantly presents symptoms following birth of the child (early infancy).

Who gets Alternating Sinus of Urachus? (Age and Sex Distribution)

• Alternating Sinus of Urachus is an extremely rare congenital urachal abnormality
• The condition is more often seen in children than adults
• It can occur both in males and females
• No specific racial or ethnic group predilection is noted

What are the Risk Factors for Alternating Sinus of Urachus? (Predisposing Factors)

• Currently, no risk factors have been clearly identified for the formation of Alternating Sinus of Urachus

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Alternating Sinus of Urachus? (Etiology)

Before birth, the urachus is a primitive structure that connects the umbilical cord to the bladder in the developing baby. The urachus helps in removal of nitrogenous wastes from the fetus through the placenta via the umbilical cord. The remnant fibrous band of urachus is called the medial umbilical ligament.

• The urachus is generally between 3-10 cm in length and 1 cm in diameter. When the urachus disappears normally around the 12^th week of fetal development, a small fibrous cord (median umbilical ligament) remains between the bladder and the umbilicus
• The urachus normally disappears before birth; but occasionally, it remains even after the child is born. This can lead to urachal abnormalities such as Alternating Sinus of Urachus. The exact reason why this occurs is unknown
• In Alternating Sinus of Urachus, the fluid-filled urachus regularly drains either into the bladder end or into the umbilicus alternatively, due to incomplete/partial closure. This form of urachal anomaly is described as a variant of umbilical-urachal sinus

What are the Signs and Symptoms of Alternating Sinus of Urachus?

Alternating Sinus of Urachus may not present any symptoms at birth or during infancy. However, later during childhood or adulthood, it may become infected and show signs and symptoms that may include:

• Abdominal pain
• Discharge of fluid or blood from the umbilicus; there may be wetness around the belly button
• Fever, due to infection
• If it is associated with urinary tract infections, then the following signs and symptoms may be noted:
  • Changes in urination frequency
  • Burning sensation or pain during urination
  • Fever and chills
  • Changes in urine smell and color
  • Sometimes, pain during sexual intercourse

How is Alternating Sinus of Urachus Diagnosed?

When Alternating Sinus of Urachus is asymptomatic, it may be detected incidentally on ultrasound scans that are performed for other medical conditions. In other cases, the following tests and exams may be ordered to diagnose the condition:

• Physical examination and evaluation of medical history
• Ultrasound studies: Prenatal abdominal ultrasound may reveal associated fetal abnormalities, if any
• A voiding cystourethrogram (VCUG) is performed to look for urinary tract abnormalities 
• Sinogram: A contrast dye is injected into the umbilicus in order to check for urachal sinus
• Computed tomography (CT scan) or magnetic resonance imaging (MRI scan) of the affected region, if necessary

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Alternating Sinus of Urachus?

• The complications of Alternating Sinus of Urachus may include higher risks for recurrent urinary tract and umbilical infections
• There is a small risk for urachal cancer; and in such cases, the entire urachus may be surgically removed
• Complications may occur with or without treatment, and in some cases, due to treatment also

How is Alternating Sinus of Urachus Treated?

The healthcare provider may recommend a ‘wait and watch’ approach for asymptomatic cases of Alternating Urachal Sinus. In some cases, the urachal abnormalities are known to resolve on their own, in the absence of any treatment.

• In case of symptoms, surgical resection and removal of the urachal remnants, by either open surgery or a laparoscopic approach may be considered
• If there is an infection associated with Alternating Urachal Sinus, then the infection is treated prior to any surgical corrections are undertaken

It is reported that surgery is rarely considered for Alternating Sinus of Urachus and the condition gets better on its own, in most cases.

How can Alternating Sinus of Urachus be Prevented?

Presently, Alternating Sinus of Urachus may not be preventable, since it is a congenital condition.

• Active research is currently being performed to explore the possibilities for treatment and prevention of such conditions
• A careful and periodic monitoring of the pregnancy is advised and recommended

What is the Prognosis of Alternating Sinus of Urachus? (Outcomes/Resolutions)

• The prognosis for Alternating Sinus of Urachus in isolation is generally good with appropriate treatment
• Occasionally, when required, a surgical removal of the symptomatic urachal remnants can result in a cure

Additional and Relevant Useful Information for Alternating Sinus of Urachus:

The following DoveMed website link is a useful resource for additional information:

https://www.dovemed.com/healthy-living/kidney-health/