• A useful diagnostic and therapeutic procedure for paranasal sinus disease Paranasal sinuses: bacterial sinusitis in the horse.

Uses

• Retrieving fluid or tissue samples for bacteriologic/microscopic examination.
• Flushing exudate from sinus to improve results of a radiographic examination.
• Passage of endoscope/arthroscope into paranasal sinuses Paranasal sinus: sinuscopy.
• Treatment of primary bacterial sinusitis Paranasal sinuses: bacterial sinusitis using lavage Paranasal sinus: lavage.

Advantages

• Can be performed under standing sedation.
• Relatively simple procedure.
• Minimal equipment required.
• The frontal and maxillary sinuses can both be sampled.

Disadvantages

• Careful positioning of centesis sites is necessary to avoid damage to underlying structures.
• Does not allow for sinus exploration.

Technical problems

• Distortion of the sinuses from masses Paranasal sinus: cyst Respiratory: neoplasia may obviate normal architecture and lavage from sinus to nasal passage through nasomaxillary aperture difficult.
• Soft tissue masses, viscous fluid, or inspissated pus may be irretrievable from a small centesis site relative to a trephine Head: trephination or bone flap Paranasal sinus: bone flap technique.

Alternative techniques

Diagnostic

• Sinuscopy Paranasal sinus: sinuscopy.
• Other exploratory techniques, eg:
  • Trephination Head: trephination.
  • Bone flaps Paranasal sinus: bone flap technique.

 Therapeutic

• Trephination Head: trephination.
• Lavage via tubes inserted at surgery Paranasal sinus: lavage.
• Bone flaps Paranasal sinus: bone flap technique.

Time required

Preparation

• Sedation and aseptic skin preparation: 10-15 min.
• Infiltration of local anesthetic: 5 min.

Procedure

• 15-30 min: depending on whether lavage and/or sinuscopy carried out.

Decision taking

Criteria for choosing test

• Fluid lines visible on skull radiographs Head: radiography.
• See Paranasal sinuses: bacterial sinusitis.
• May also be useful in diagnosis of paranasal sinus cyst Paranasal sinus: cyst; but further intervention is needed for treatment

Risk assessment

• Incorrect placement of centesis sites may cause damage to underlying structures.
• The maxillary sinuses must be approached cautiously in young horses due to risk of injury to tooth roots.