​What is Surgery – Branchial Cyst, Sinus, Fistula

​What is Surgery – Branchial Cyst, Sinus, Fistula  
DEFINITION 
Neck swelling or discharge caused by incomplete pharyngeal clefts and pouches obliteration during embryonic development. 

AETIOLOGY
Although the specific embryological origin is contested, 95% of them derive from congenital remains of the second pharyngeal pouch or branchial cleft (possibly incomplete involution or ectopic tissue). 

EPIDEMIOLOGY 
Uncommon. Branchial cysts are the most prevalent, appearing most frequently in the third decade and presenting with variations. Children are more likely to have fistulae and sinuses. 

HISTORY The patient has a lateral neck swelling that can change in size over time; it is normally painless until inflammation and infection occur, at which point it becomes painful and red. A sinus or fistula appears as a depression in the neck that discharges mucus or mucopurulent fluid. 



EXAMINATION 
A lump (cyst) is located just deep to the sternocleidomastoid at the intersection of its upper and lower two-thirds.  The swelling is normally ovoid, smooth, and firm on palpation, but it can be soft in the early stages, fluctuate, and transilluminate. 2% are bilateral.

 The intersection of the middle and lower one-third of the anterior edge of the sternocleidomastoid is where the external opening of a branchial sinus or fistula is located. 

PATHOLOGY/PATHOGENESIS
In the fifth week of development, branchial clefts, or grooves in the neck, with branchial arches in between, are form. The external auditory meatus remains in the first cleft, while the others usually fade away. 

A cyst, sinus, or fistula may form if parts of the second cleft remain. Squamous or respiratory epithelium lines the cysts, which contain turbid fluid containing epithelial debris and cholesterol crystals, as well as lymphoid tissue in rare cases.

 A branchial fistula connects the internal and external carotid arteries in the oropharynx, terminating superior to the hypoglossal nerve and inferior to the glossopharyngeal nerve in the posterior section of the tonsillar fossa. 

INVESTIGATIONS 
The cyst can be visualised with ultrasound, CT, or MRI scanning. FNA: Used to distinguish thyroid cancer and mucoepidermoid carcinomas of the salivary glands that may have a significant cystic component from cervical lymph node metastases in older people (e.g. thyroid cancer and mucoepidermoid carcinomas of the salivary glands that may have a significant cystic component). 

MANAGEMENT
 Surgery: The cyst and any related sinus or tract are surgically removed. A transverse neck incision is commonly used for this procedure. To gain access to the cyst, the platysma is split and the sternomastoid is retracted posteriorly. It is then carefully dissected with identification and nerve injury avoided before being removed (especially the vagus, hypoglossal and spinal accessory nerves). Before removing a branchial cyst, the abscess should be drained and medicines provided to prevent infection. 

COMPLICATIONS 
Infection, branchial cyst abscess, nerve injury during surgery, and inadequate sinus or fistula tract excision are all possible complications. 

PROGNOSIS 
Good, with full excision resulting in cure. If there has been a previous infection, the chances of recurrence are higher.