• Treatment of sinusitis involves the same basic principles as those for any closed-space infection including adequate drainage, lavage with large volumes of sterile fluid and antimicrobial therapy.
• Systems to allow long-term lavage of the paranasal sinuses can be fitted in the standing patient or during surgery under general anesthesia (GA).

Uses

• Part of initial treatment for sinusitis, especially the primary type.
• Adjunct to post-operative treatment of surgical cases involving the paranasal sinuses, eg maxillary cysts, dental disease Teeth: periodontal disease, where secondary sinusitis has occurred Paranasal sinuses: bacterial sinusitis.

Advantages

• Can be performed under standing sedation.
• Relatively simple procedure.
• Very effective in cases of primary sinusitis.

Disadvantages

• Not effective in secondary sinusitis cases unless primary problem is addressed, eg dental disease.
• Usually not effective if pus has become inspissated.

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.

Alternative techniques

• Drainage, eg trephination Head: trephination, bone flaps Paranasal sinus: bone flap technique, ostia enlargement Paranasal sinus: drainage ostia - enlargement - adequate drainage whether natural or artificially created is essential for lavage to be effective.
• Systemic antibiotics/anti-inflammatories Paranasal sinuses: bacterial sinusitis.
• Treatment of secondary sinusitis primary causal problem, eg removal of tooth or maxillary cyst.
• Surgical exploration of paranasal sinuses via trephination Head: trephination or bone flap Paranasal sinus: bone flap technique.

Time required

Preparation

• Sedation: 10-15 min.
• Aseptic skin preparation: 10-15 min.
• Infiltration of local anesthetic: 10 min.
• If under general anesthesia - induction and maintenance: 20 min.

Procedure

• If implanted after centesis:
  • Centesis: 10 min.
  • Catheter inserted and sutured: 5 min.
• If under general anesthesia via bone flap or trephine: same as bone flap Paranasal sinus: bone flap technique or trephination Head: trephination + 10 min per catheter.

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.