Branchial cleft cysts and sinuses

Note that 'branchial cleft' is outdated terminology according to Langman's - now 'pharyngeal cleft'. However the persistent cyst is still called a 'branchial cleft cyst'.

Epidemiology

• 20% of neck lumps in children

Definitions

• Fistula - passage between skin and pharynx
• Sinus - opening in skin connects to deeper tract, but no communication with pharynx
• Cyst - cystic swelling along the tract

Embryological basis

• See 'embryology'
• Each pharyngeal arch may have an adjacent pouch and a cleft
• The clefts are only transient structures and should disappear, but can persist as a branchial cleft cyst or fistula

First branchial cleft (8%)

• Opening near angle of mandible or submandibular triangle

Second branchial cleft (90-95%)

• 10% bilateral
• Fistula is likely to open on the skin anterior to the lower third of SCM, then penetrates platysma, ascends along carotid sheath to the level of the hyoid bone, turns medially and always passes between internal and external carotid arteries, then behind the posterior belly of digastric and stylohoid, with internal opening into the tonsillar fossa of the pharynx
• Branchial cyst is likely to lie deep to middle third of SCM

Third and fourth branchial clefts (2%)

• Lower down in neck, level of thyroid

Management

• Conservative
• Ultrasound-guided sclerotherapy
• Surgical excision when not infected

Technique

• GA
• Consider injecting blue dye into tract
• Incision over cyst, along skin tension lines, carried down through platysma
• Consider surrounding structures
  • EJV
  • Greater auricular nerve
  • SCM - may not see
• Sub-platysmal flap superiorly, following EJV and GAN
• Skeletonise anterior SCM
• Now identify cyst, free from attachments circumferentially, and dissect along tract
• May need to make a 'step-ladder' incision higher in neck, at level of hyoid
• If tract persists higher, ligate it as high as easily reachable, ideally right on pharynx muscle
• Drain
• Close - straps, platysma, skin