gutteral pouches, by dr. rekha pathak, senior scientist ivri

Empyema of Gutteral pouchesEmpyema of Gutteral pouches

• Only in equines• GP – large mucous

sac which is ventral deverticulum of the eustachian tube and situated on both sides on dorsal surface of the pharynx

• Eustachian tubes: passage on each side, from throat to the middle ear and serve to maintain even atmospheric pressure upon the inner surface of the ear drum or tympanum. Open widely in the act of swallowing or yawning.

Empyema of Gutteral pouchesEmpyema of Gutteral pouches

• Collection of pus in GP- as a result of infection from pharynx through the Eustachian tube .

• Sequelae of influenza/ strangles.

• Pus may be partly inspissated (Chondroids)

• Persists for want of complete drainage

Empyema of Gutteral pouchesEmpyema of Gutteral pouches

• Symptoms: • Intermittent nasal

discharge – head is lowered during feeding or drinking.

• From both nostrils even if one gutteral pouch is affected

• Thin and not foul smelling

• Press the pouch with hand – discharge is seen

• Difficulty in swallowing and breathing because of pressure on pharynx and larynx

• Swelling of submaxillary (mandibular) lymph glands

• Holding of the head towards the sound side

• Rattling sound during trotting – agitation of the contents

• Pass a Gunther’s catheter into the pouch• From nostril into pharynx and carefully directed

into the opening of the eustachian tube at the pharynx to reach the GP of the affected side

PrognosisPrognosis

• Favourable if complete drainage is provided by surgical operation

• Death rarely occurs due to inflammation and ulceration of mucus memberane

• Death may occur by severe hemorhage

• Inspiration pneumonia due to ingested food materials entering lungs because of dysphagia

Treatment Treatment

• Early stages: antibiotic therapy may be helpful

• Once pus is formed , drainage is to be effected surgically

• Irrigate with mild AS solutions after passing catheter

• Chondroids cannot be removed

Surgical Surgical

• 2 sites• Incising along the

anterio- inferior border of the wing of atlas and doing hyovertebrotomy

• Viborg’s triangle

• GA is prefferred• Viborg’s can be done

under LA

• Technique: • Area defined by

tendon of sternomandibular muscle, linguofacial (external maxillary ) vein, and caudal border of vertical ramus of mandible

• 4-6 cm incision dorsal and parallel with linguofacial vein from the border of mandible caudad

• Separate the subcutaneous tissue

• Reflect the base of parotid gland- avoid trauma to gland and duct, lingofacial vein, branches of the vagus nerve along the floor of gutteral pouch

• Exposes the GP – distended in pathologic state

• Grasp the memberane with foreceps and incise with scissors

• Wound is left open for drainage or a drain is inserted

• Granulation (secondary intension)

Hyovertebrotomy Approach Hyovertebrotomy Approach

• exposes the Dorsolateral aspect of GP

• More difficult• More vessels and

nerves in surgical site• 8-10 cm incision –

parallel and just cranial to wing of atlas

Hyovertebrotomy Approach Hyovertebrotomy Approach •

exposes the parotid salivary gland and overlying parotidoauricularis muscle

• Ventral part of muscle is incised – incise the parotid facia on its caudal border

• Reflect the parotid craniad

• Caudal auricular nerve crosses obliquely in the dorsal aspect of field

• Reflect it caudad

• Reflection of parotid reveals occipitohyoideus and digastricus m craniodorsally and rectus capitis caudodorsally

• One can see the mandibular salivary gland ventrally

• Blunt dissection through areolar tissue exposes the dorsolateral wall of GP

• Entry is made between glossopharyngeal nerve rostrally and vagus nerve caudally

• Avoid the internal carotid art.

• Incise GP • If necessary after

drainage fix a drain• Close the incision, GP

memberane by simple interrupted – synthetic absorbable

• Close the facia associated with parotid gland

• Close the skin