Normal Pharyngeal (Branchial) arches

· Branchial pouches

· Branchial clefts

· Floor of pharynx

· Respiratory system

Congenital malformations

· Branchial cysts

· Thyroglosal cyst

· Oesophagotracheal fistulae

· 1st arch syndrome

· Lung abnormalities

Development

· Begins in 4th week

· pouches (endodermal) and clefts (ectodermal) appear ® push mesenchyme into pharyngeal arches.

· Each arch (and \ associated pouch and cleft) have their own neurovascular supply

· Arch componenets

— Mesenchyme

— Ectoderm

— Endoderm

— Neural crest cells

— Nerve

— Artery

Arches

· C: cartilage, M: mesoderm, E: ecto / endoderm, N: nerve, A: artery

Arch I

N: Trigeminal (V)

A: Maxillary artery

C: Maxillary process, meckels cartilage (Mandible formed by membranous ossification around this), incus, malleus, sphenomandibular ligament

M: muscles of mastication (Temporal, masseter, pterygoid), mylohyoid, ant belly digastric, tensor tympani, tensor veli palatini

E: Glands of anterior 2/3 tongue

Arch II

N: Facial (VII)

A: Stapedial artery (ECA)

C: stapes, styloid process, stylohyoid ligament, lesser horn & upper body of hyoid

M: muscles of facial expression (Buccinator, auricularis, frontalis, platysma, orbicularis oris and oculi), stapedius, stylohyoid & post belly digastric

Arch III

N: Glossopharyngeal (IX)

A: Internal carotid

C: lower body and greater horn of hyoid

M: stylopharyngeus

E: glands post 1/3 tongue, mucous membrane of post 1/3 tongue and anterior surface of epiglottis

Arch IV

· The cartilaginous component of IV and VI fuse together

N: Vagus (X), Superior laryngeal

A: R subclavian, aortic arch

C: thyroid, cricoid, arytenoid, corniculate and cuneiform cartilages

M: cricothyroid, levator palatini, constricors of pharynx

Arch VI

N: Vagus (X), Recurrent laryngeal

A: R &L pulmonary, ligamentum areteriosum

C: thyroid, cricoid, arytenoid, corniculate and cuneiform cartilages

M: Intrinsic muscles of the larynx

Pouches

1. Tympanic cavity

Mastoid antrum

Tympanic membrane (where contacts 1st cleft)

Eustachian tube

2. Palatine tonsil (Pouch obliterated, epi buds into mesenchyme’ tonsil)

3. Inferior PT (Dorsal)

Thymus (Ventral)

4. Superior PT (Doral)

5. Ultimobranchial body (C cells from neural crest ® thyroid)

Clefts

1 External auditory meatus

2-4 Close over @ 6/52 Arch II grows over III and IV, incomplete closure results in Branchial cyst or sinus. Sinus invariably comes out in palatine tonsil and passes between internal and external carotids to the lateral aspect of the neck anterior to SCM. Cysts commonly at the angle of the jaw.

Floor

Tongue

· Appears 4/52 as swelling in floor

· 2 lateral lingual swellings, 1 median (tubercule impar) from arch I

· 1 posterior (copula) from arch II

Thyroid

· Appears 4/52

· epithelial proliferation in floor of mouth between tubercule impar and copula.

· Penetrates mesoderm forming the thyroid diverticulum (initially hollow, becomes solid),

· divides into 2 and descends anterior to pharynx in front of hyoid.

· Track of descent is the thyroglossal tract and site of origin marked by the foramen caecum @ juncn

of anterior 2/3 and posterior 1/3 of tongue.

· Reaches final position 7/52 and thyroglossal tract degenerates and dissapears.

· Thyroid begins to function @ 3/12.

· A pyramidal lobe is present in 50%, may be attached to the hyoid and occurs more comoonly to the

L of the isthmus.

· Parafollicular or C cells migrate from neural crest to 4th and 5th pouches and then to predominantly

the superior aspect of the thyroid

H&N 5

Developmental abnormalities

Branchial cleft remnants

· All branchial cleft remnants are congenital abnormalities present at birth

· Branchial cleft sinuses present with cutaneous openings often noted in infancy marked by skin tags or subcutaneous cartilaginous remnants

· Branchial cysts present later in childhood when they accumulate secretions

· Peak incidence 2nd & 3rd decades

Defintions

· Branchial fistula: The fistula has both an internal and external opening

· Branchial sinus: The lower opening and main tract are present but the tract does not communicate with the pharynx internally

· Branchial cyst: The central portion only of the cleft remains patent with a spherical neck swelling

Aetiology

· Either formed during fusion of the 2nd and (6th) arch

— Failure of fusion of the 2nd - 5th clefts ® cervical sinus ® branchial cyst

· O r epithelial cell rests within cervical lymph nodes

— Become cystic in later life, ? stimulus

Clinical

First branchial cleft remnants

· Sinus opening near the angle of mandible or in region of submandibular triangle

            Submandibular triangle (inverted triangle):

                        Roof:                           Platysma

                        Base:                           Lower broader of mandible to its angle

                        Apex and sides:           Triangle borader of digastric muscle

                        Floor:                          Mylohyloid muscle

                        Content:                      artery: external and internal caroid art

                                                                        Facial artery

                                                            Vein:    Internal jugular, facial vein

                                                            Nerve: Mandibular and cervical Facial nerve

                                                                        hypoglossal nerve

                                                                        vagus nerve

                                                                        lingual nerve

                                                            Node and gland: submandibular gland&node

· Fistula tract typically runs

            superficial to the skin of angle of mandible and opening to external   auditory canal

         lie anteriorly or occasional posterior to the main trunk of facial nerve

Second branchial cleft remnants

· External opening along the anterior border of SCM in its lower 1/3; 10% bilateral; six times more common than first arch remnants.

· Tract passes

            Deep to the platysma and deep cervical fascia

            Above the hyloid bone

                        it turns medially and underneath the stylohyloid and the                                 posterior belly of digastric

                        passes Between the carotid bifurcation

                        anterior to hypoglossal nerve

            to communicates with the pharynx at the tonsillar fossa

Third and forth cleft remnants

· Internal opening is typically located in the piriform sinus

· Often present as a firm mass in the subcutaneous tissue with or without associated sinus or fistula.

· Third branchial cleft sinus presents as a mass lower in the neck than the second

·  3rd cleft, tract passes between common carotid and vagus

· 4th cleft, tract passes caudal to arch of aorta or R subclavian

· Often present as a left thyroid lobe abscess

Investigations

· Radiological Ix not usually required for first and second branchial abnormalities

            But Fistulogram or USS: Helpful to identify the track anatomy

· Barium studies or CT may be useful in piriform sinus fistula

· Contrast esophagogram may show the fistula between the piriform sinus and neck

Treatment

· Complete surgical excision

If an abscess is present, it is initially drained

If infection is present antibiotics are administered and formal excision is delayed as surgery in the presence of infection increases the risk of recurrence and injury to facial nerve (first cleft) or hypoglossal nerve (second cleft).

Excision is recommended at diagnosis for uninfected lesions

Surgery for infants is delayed until 3-6 mo of age

· Complications of surgery – see surgery

Preauricular cysts or sinus

· Probable 1st cleft abnormality

· Lined with squamous epithelium

· usually lies in tragus, and running medio-inferiorly to join the ear cartilage

· Can have close proximity to facial nerve

Collaural fistula

· Passes from external auditary meatus through parotid to neck

Surgery

· If symptomatic

· Incision anterior to pinna

· Extend into parotidectomy incision if required

· May need to mobilise parotid / do superficial parotidectomy to visulaise nerve

· Full excision of tract

Branchial fistulae

· Less common than cysts

· Bilateral in 20%

· F>M

· Majority present in 1st decade

— Can present into adulthood

· Most likely arise from cervical sinus (branchial cyst)

External branchial fistula

· Communication with skin from cervical sinus

· Lined with squamous epithelium

· Most common 2nd cleft

— Lateral aspect of neck anterior to SCM

— Passes between ICA & ECA

· Fistulae involving 3rd and 4th clefts are rare

Internal branchial fistula

· Communication with pharynx from cervical sinus

· Can be lined with cilliated columnar epithelium

— Rare

— Generally opens in tonsillar region (2nd pouch)

— Less commonly opens in pyriform sinus (3rd pouch)

Complications

· Infection

— Can be recurrent

· SCC

— Very rare

Surgery

· Excise

· Need to include fistula opening

Discuss branchial fistulas

• most commonly of the second branchial cleft

• present in infancy

• second cleft

• arise tonsillar fossa

• Course between internal and external carotid arteries

• pass over hypoglossal nerve

• pass beneath glossopharyngeal nerve

• present anterior to sternocleidomastoid

• third cleft

• arise from piriform sinus

• pass posterior to carotid vessels

• pass over hypoglossal nerve

• present anterior to sternocleidomastoid

Discuss branchial cyst

• commonly presents in young adults (as epithelial debris accumulates and infection may occur)

• lined by stratified squamous epithelium

• usually lie between carotid sheath and sternocleidomastoid, bulging into the

carotid triangle from behind the muscle

• yellow fluid, rich in cholesterol crystals on microscopy

Sabistons: Branchial Cleft Remnants
The mature structures of the head and neck are embryologically derived from six pairs of branchial arches, their intervening clefts externally, and pouches internally. Congenital cysts, sinuses, or fistulas result from failure of these structures to regress, persisting in an aberrant location. The location of these remnants generally dictates their embryologic origin and guides the subsequent operative approach. Failure to understand the embryology may result in incomplete resection or injury to adjacent structures.

By definition, all branchial remnants are present at the time of birth, although they may not become clinically evident until later in life. In children, fistulas are more common than external sinuses, which are more common than cysts. In adults, cysts predominate. The clinical presentation may range from a continuous mucoid drainage from a fistula or sinus to the development of a cystic mass that may become infected. Branchial remnants may also be palpable as cartilaginous lumps or cords corresponding with a fistulous tract. Dermal pits or skin tags may also be evident.

First branchial remnants are typically located in the front or back of the ear, or in the upper neck in the region of the mandible. Fistulas typically course through the parotid gland, deep, or through branches of the facial nerve, and end in the external auditory canal.

Remnants from the second branchial cleft are the most common. The external ostium of these remnants is located along the anterior border of the sternocleidomastoid muscle, usually in the vicinity of the upper half to lower third of the muscle. The course of the fistula must be anticipated preoperatively because stepladder counterincisions are often necessary to excise the fistula completely ( Fig. 71-4 ). Typically, the fistula penetrates the platysma, ascends along the carotid sheath to the level of the hyoid bone, and then turns medially to extend between the carotid artery bifurcation. The fistula then courses behind the posterior belly of the digastric and stylohyoid muscles to end in the tonsillar fossa.
The mature structures of the head and neck are embryologically derived from six pairs of branchial arches, their intervening clefts externally, and pouches internally. Congenital cysts, sinuses, or fistulas result from failure of these structures to regress, persisting in an aberrant location. The location of these remnants generally dictates their embryologic origin and guides the subsequent operative approach. Failure to understand the embryology may result in incomplete resection or injury to adjacent structures.

By definition, all branchial remnants are present at the time of birth, although they may not become clinically evident until later in life. In children, fistulas are more common than external sinuses, which are more common than cysts. In adults, cysts predominate. The clinical presentation may range from a continuous mucoid drainage from a fistula or sinus to the development of a cystic mass that may become infected. Branchial remnants may also be palpable as cartilaginous lumps or cords corresponding with a fistulous tract. Dermal pits or skin tags may also be evident.

First branchial remnants are typically located in the front or back of the ear, or in the upper neck in the region of the mandible. Fistulas typically course through the parotid gland, deep, or through branches of the facial nerve, and end in the external auditory canal.

Remnants from the second branchial cleft are the most common. The external ostium of these remnants is located along the anterior border of the sternocleidomastoid muscle, usually in the vicinity of the upper half to lower third of the muscle. The course of the fistula must be anticipated preoperatively because stepladder counterincisions are often necessary to excise the fistula completely ( Fig. 71-4 ). Typically, the fistula penetrates the platysma, ascends along the carotid sheath to the level of the hyoid bone, and then turns medially to extend between the carotid artery bifurcation. The fistula then courses behind the posterior belly of the digastric and stylohyoid muscles to end in the tonsillar fossa.

How do you excise a Second branchial remnant sinus/fistula

· GA. Supine. Neck extended. Head ring. Head-up tilt. Head turned to opposite side.

· Transverse elliptical skin incision to include sinus opening

· Place lockhart Mummary fistula probe in tract. Grasp the external opening with Allis and feel the course of fibrous tract.

· Dissection through platsyma and deep fascia coring out the tract using diathermy and ascending along carotid sheath to level of hyoid bone.

· Dissection then turns medially between the branches of carotid artery, behind the posterior belly of digastric and stylohyoid muscle and infront of hypoglossal.

· A step ladder incision is usually required at the level of hyoid in the patient with the longer tract to complete dissection. Raise subplatsymal flaps and dissect tract free at the level of the hyoid. Pass the tract of tissue under the skin bridge between the two incisions and then proceed follow the tract medially feeling the fibrous cord with fingers

· Divide the digastric near the central tendon taking care not to damage the internal or external carotid or hypoglossal or glossopharyngeal nerves.

· Ask anaesthetist to place finger in mouth in the region of tonsillar fossa and press gently laterally so that the end point of dissection can be identified  and ligated with o Vicryl

· Amputate the tract where it penetrates the middle constrictor just above the glossopharyngeal nerve and tie off the pharyngeal end

· I check for haemostasis and close in layers with 2/0 Vicryl using drainge with a 10F redivac drain.

How do you excise a First branchial remnant sinus/fistula

· GA. Supine. Neck extended. Head ring. Drape to allow visualization of the corner of eye and mouth.

· I use a facial nerve stimulator

· Transverse incision to include sinus opening usually at the angle of mandible

· I mobilize the superficial lobe of the parotid gland to expose the tract and protect the facial nerve.

· Often the superficial lobe requires excision to identify and protect the facial nerve

· Dissection continue, guided by a fistula probe cephalad in proximity to the parotid and facial nerve to end in the external auditory canal.

How do you excise a third or forth branchial remnant sinus/fistula

· GA. Supine. Neck extended. Head ring.

· A standard collar incision is made as for thyroidectomy

· The appropriate thyroid lobe is mobilized and recurrent and superior laryngeal nerves and parathyroid glands are identified and protected

· If no discrete tract or cyst is identified the fibers of the inferior constrictor are bluntly separated using an artery clip to expose the piriform recess preserving the external branch of the superior laryngeal nerve

· A tract is often found passing inferior and external to the RLN along trachea to superior pole of thyroid

· If the tract penetrates the capsule of the thyroid to end in the parenchyma of the gland thyroid lobectomy should be performed

How do you excise a branchial cyst

· GA. Supine. Neck extended. Head ring. Head-up tilt. Head turned to opposite side.

· Transverse skin incision overlying the lesion (usually the upper and middle 1/3 of SCM) from 1cm short of midline to half-way between the anterior and posterior borders of SCM.

· Raise subplatsymal flaps

· Incise the investing layer of cervical fascia along anterior border of SCM

· Insert self-retainer to flaps and Langenbach to retract SCM medially

· Use blunt dissection around cyst performed by gently opening a curved artery and diving the tissue with diathermy being careful not to rupture the cyst.

· The deep aspect of the cyst overlies the carotid bifurcation and X

· Dissect behind the cyst to the mobilizing it from the middle constrictor avoiding the X and IX

· If the cyst extends upwards  excise a segment of the posterior belly of digastric and proceed as for a fistula.

· I check for haemostasis and close in layers with 2/0 Vicryl using drainge with a 10F redivac drain.

· Complications of surgery for Branchial sinus/fistula/cyst

Immediate:

Bleeding from damage to critical vascular structures (eg branch of carotid artery)

Airway compromise from expanding neck haematoma

Early:

Infection of skin – more common if previous infection

Damage to critical nerves – hypoglossal nerve (Second cleft excision); Facial nerve (first cleft) and RLN or SLN (third and forth)

Late:

Recurrence – implies failure to completely excise the tract

How do you excise a Second branchial remnant sinus/fistula

· GA. Supine. Neck extended. Head ring. Head-up tilt. Head turned to opposite side.

· Transverse elliptical skin incision to include sinus opening

· Place lockhart Mummary fistula probe in tract. Grasp the external opening with Allis and feel the course of fibrous tract.

· Dissection through platsyma and deep fascia coring out the tract using diathermy and ascending along carotid sheath to level of hyoid bone.

· Dissection then turns medially between the branches of carotid artery, behind the posterior belly of digastric and stylohyoid muscle and infront of hypoglossal.

· A step ladder incision is usually required at the level of hyoid in the patient with the longer tract to complete dissection. Raise subplatsymal flaps and dissect tract free at the level of the hyoid. Pass the tract of tissue under the skin bridge between the two incisions and then proceed follow the tract medially feeling the fibrous cord with fingers

· Divide the digastric near the central tendon taking care not to damage the internal or external carotid or hypoglossal or glossopharyngeal nerves.

· Ask anaesthetist to place finger in mouth in the region of tonsillar fossa and press gently laterally so that the end point of dissection can be identified  and ligated with o Vicryl

· Amputate the tract where it penetrates the middle constrictor just above the glossopharyngeal nerve and tie off the pharyngeal end

· I check for haemostasis and close in layers with 2/0 Vicryl using drainge with a 10F redivac drain.

How do you excise a First branchial remnant sinus/fistula

· GA. Supine. Neck extended. Head ring. Drape to allow visualization of the corner of eye and mouth.

· I use a facial nerve stimulator

· Transverse incision to include sinus opening usually at the angle of mandible

· I mobilize the superficial lobe of the parotid gland to expose the tract and protect the facial nerve.

· Often the superficial lobe requires excision to identify and protect the facial nerve

· Dissection continue, guided by a fistula probe cephalad in proximity to the parotid and facial nerve to end in the external auditory canal.

How do you excise a third or forth branchial remnant sinus/fistula

· GA. Supine. Neck extended. Head ring.

· A standard collar incision is made as for thyroidectomy

· The appropriate thyroid lobe is mobilized and recurrent and superior laryngeal nerves and parathyroid glands are identified and protected

· If no discrete tract or cyst is identified the fibers of the inferior constrictor are bluntly separated using an artery clip to expose the piriform recess preserving the external branch of the superior laryngeal nerve

· A tract is often found passing inferior and external to the RLN along trachea to superior pole of thyroid

· If the tract penetrates the capsule of the thyroid to end in the parenchyma of the gland thyroid lobectomy should be performed

How do you excise a branchial cyst

· GA. Supine. Neck extended. Head ring. Head-up tilt. Head turned to opposite side.

· Transverse skin incision overlying the lesion (usually the upper and middle 1/3 of SCM) from 1cm short of midline to half-way between the anterior and posterior borders of SCM.

· Raise subplatsymal flaps

· Incise the investing layer of cervical fascia along anterior border of SCM

· Insert self-retainer to flaps and Langenbach to retract SCM medially

· Use blunt dissection around cyst performed by gently opening a curved artery and diving the tissue with diathermy being careful not to rupture the cyst.

· The deep aspect of the cyst overlies the carotid bifurcation and X

· Dissect behind the cyst to the mobilizing it from the middle constrictor avoiding the X and IX

· If the cyst extends upwards  excise a segment of the posterior belly of digastric and proceed as for a fistula.

· I check for haemostasis and close in layers with 2/0 Vicryl using drainge with a 10F redivac drain.

· Complications of surgery for Branchial sinus/fistula/cyst

Immediate:

Bleeding from damage to critical vascular structures (eg branch of carotid artery)

Airway compromise from expanding neck haematoma

Early:

Infection of skin – more common if previous infection

Damage to critical nerves – hypoglossal nerve (Second cleft excision); Facial nerve (first cleft) and RLN or SLN (third and forth)

Late:

Recurrence – implies failure to completely excise the tract