Branchial Fistulas: Symptoms, Causes, Treatment, Diagnosis, Epidemiology

Branchial fistula is a condition that occurs during the stage of embryonic development. In the early stages of prenatal development, the face and neck forms from 5 building blocks known as branchial arches which are separated from each other through clefts. Usually, these structures are reabsorbed; however, in rare cases, this does not happen and these structures remain. They can connect with the skin and can drain sloughed skin. This is done through the branchial sinus which is a small opening on the skin. They may also connect with the throat lining and may drain mucus from a small opening which is called the branchial fistula. Both these things might not occur at all and over time it might grow into a branchial cyst. The occurrence of all these abnormalities is called branchial anomalies.

Talking of symptoms of Branchial fistula, in most cases, it has been seen that the early symptoms of Branchial fistula become visible either during the later part of childhood or the early part of adulthood. The surfacing of a solitary single painless mass that was not noticed earlier becomes visible.⁽¹⁾ This could be due to the fistula or the cyst getting infected due to an upper respiratory tract infection. It has been seen that fistulas invariably remain asymptomatic until there is an infection that affects it. Hence, try and get a complete check-up done for a branchial fistula or branchial anomaly if your child has the following symptoms ⁽¹⁾:

• A draining pit on their neck
• A draining pit around the region of the ear
• An area of fullness on the neck.

Having discerned the symptoms that are the first indications of the Branchial fistula, it is eminent here to mention that branchial fistulas can be of four types. Let us take a detailed look at them ⁽¹⁾.

1. Type I Branchial Fistula: It can be found deep in platysma muscle and the region of overlying cervical fascia.
2. Type II Branchial Fistula: This is thought to exists due to the persistence of the sinus in His. They are in contact with the great vessels and are found behind the submandibular gland.
3. Type III Branchial Fistula: It is found in the tract courses between the external and the internal carotid arteries and can also extend to the lateral wall of pharynx or the base of the skull.
4. Type IV Branchial Fistula: It starts from the remnants of pharyngeal pouch and is found next to the pharyngeal wall.

The condition is something that happens to be present in an infant at the time of birth. However, it has been seen that the initiation of the condition generally happens during the first or the second decade of life. Typically the presence of branchial fistulas or branchial anomalies can be found on the front part of the neck. However they can also be spotted on the lowers part of the neck, the region around which a person has the thyroid glands or the area around the ear. These branchial anomalies could get enlarged due to infection in the upper respiratory tract.⁽¹⁾

The accurate incidence rate of branchial fistulas in the US population is unknown.⁽²⁾ Branchial fistulas are rare anomalies of embryonic development of the branchial apparatus. However, anomalies of the second branchial arch and pouch are common which accounts for 90-95% of the cases.^(1,3)

Precisely speaking the exact reason that triggers branchial fistulas in some infants or children is not known. It is a structural or developmental problem of the infant that gets triggered off as early as the embryonic stage. It can be said that certain changes in the structure, nature and the constitution of the womb can lead to this condition in certain children.⁽¹⁾ Again in some cases, it has been seen that the element of family history also has a part to play in the development of branchial fistulas. More investigations are being carried out in the domain so that more detailed and well-founded causes for the condition can be fathomed.

Clinical and radiological investigations are primarily used for the diagnosis of branchial fistulas In many cases, a fistulogram is also performed that helps to delineate the tract and is commonly used to investigate cases of the branchial anomaly. In certain situations, a tomography scan or a CT fistulogram is also used to get images of the neck.⁽¹⁾ This process also helps to discern the type of lesion which is required to be identified to decide on the nature of the surgery that must be taken up for the case. It also reduces the chances of recurrence. MRI is the most advantageous process of investigation that helps the doctors to get a clear view of the growth and its condition. In places where MRI and CT scan are unavailable, ultrasound is used to get the best images possible.⁽¹⁾ However, the clarity of the images might be compromised even with the use of high-resolution transducers.

The condition of the branchial fistula is not treatable with medicines. Surgical excision is the only choice of treatment.⁽⁴⁾ However, there can be different surgical approaches that can be taken up for the management of the condition. Some of the common approaches are transcervical approaches that could be done through the process of long incision or that of a step ladder approach.⁽¹⁾ Out of these two approaches the stepladder approach happens to be the more common that was introduced by Bailey in the year 1933.

Improved imagery can lead to better diagnosis and also improved treatment of the branchial fistulas. This is why the domain of branchial fistula is seeing a large number of research and investigations. These investigations are just as directed towards finding better ways of removing the lesions. The researchers also aim at finding better methods and ways to diagnose branchial fistulas. In the realm of diagnosis, it can be said that the importance of getting a better, closer and more accurate image of branchial fistulas is paramount. This is one of the ways and processes through which improved assessment of the condition can be made, which can be a huge benefit for the doctors and surgeons. Further research is ongoing that will give us a better understanding of the causes and the reasons for the occurrence of branchial fistulas. This can help us to take preventive steps so that fewer infants and children are affected by branchial fistulas in the future.

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Also Read:

• Branchial Cleft Cyst: Causes, Symptoms, Treatment, Prognosis, Diagnosis