• Surgical access to the tympanic bulla via a ventral approach osteotomy.
• Lateral bulla osteotomy is often performed after carrying out either a partial ear canal ablation (PECA) or a total ear canal ablation (TECA).

Uses

• Investigation and treatment of otitis media when medical therapy fails.
• For middle ear bacterial and fungal infections.
• Where there is extension of the infection into the bone of the tympanum or external bony meatus, or where the tympanum has ruptured extending the disease to an otitis externa.
• Investigation and treatment of neoplasia of the middle ear.

Advantages

• Allows full exposure of the contents of the tympanic bulla.
• Facilitates sampling for bacterial or fungal culture and histopathology.
• Facilitates curettage, drainage and flushing of purulent debris.
• Provides a route for administration of topical treatment.
• Allows placement of antibiotic impregnated polymethylmethacrylate PMMA beads.

Disadvantages

• Post-operative complications.
• Advanced surgical skills and specialized instrumentation are necessary.

Technical problems

• The lapine tympanic bulla is poorly accessible, being guarded laterally by the caudal parts of the mandible.
• The approach from the ventral aspect to the tympanic bulla passes major structures such as the mandibular salivary glands, the maxillary and linguofacial arteries, facial, lingual and external jugular veins and the facial nerve which exits the skull caudal to the bulla, between it and the mastoid process.

Alternative techniques

• Myringotomy allows flushing the bulla via the ear canal, but recurrence of infection is highly likely as drainage of thick purulent material through the eustachian tube is poor.
• Total ear canal ablation Ear: total ear canal ablation and ostectomy of the tympanic bulla in cases of neoplasia or chronic otitis externa Otitis externa and media Otitis media/interna.

Time required

Preparation

• 10 min.
• Up to 30 min if a combined surgical approach via the external ear canal is needed.

Procedure

• 30-60 min.

Decision taking

Criteria for choosing test

• Chronic and clinically significant changes in the tympanic bulla, unresponsive to medical therapy.
• Diagnostic imaging (radiography Radiography: skull (basic), CT Computed tomography, MRI Magnetic resonance imaging) may show increased density within the bullae indicating presence of fluids, exudates, infection, abscessation or neoplasia.

Risk assessment

• The client should be aware that there are risks involved with the technique both in terms of collateral damage, exacerbation of inner ear signs and failure of the procedure to control infection.