Page 256 - Clinical Manual of Small Animal Endosurgery

244 Clinical Manual of Small Animal Endosurgery

air drill. Slow, careful drilling into the sinus is advised to avoid iatrogeni-
cally damaging the far wall of the sinus or delicate deeper structures.
Once the hole is made, it is not unusual for the release of pressure in
the sinus to allow for copious discharge to come out of the hole spon-
taneously. This discharge, be it fluid or tissue, can be collected for cytol-
ogy, culture or histopathology. Once material for culture has been
recovered it is advised to give an intra-operative parenteral dose of a
broad-spectrum antibiotic. Subsequent antibiotic therapy can be dictated
by the clinical presentation and culture results.
The endoscope can now be introduced into the sinus and irrigation
should begin. This will allow for clearing of any debris within the sinus
and adequate visualisation of the entire cavity. In some cases of severe
sinus disease the deep recesses of the sinus and the communication
between other recesses of the frontal sinuses and the rhinarium itself can
be appreciated.
Biopsies of material present in the sinus can be taken for laboratory
evaluation. Residual fluid from irrigation or from underlying disease
processes should then be removed. There is little need to try and close
the bony defect, but the skin incision can often be closed in a single layer
with one or two simple interrupted or cruciate sutures of non-absorbable
monofilament suture material.

Review of selected pathologies

Lymphoplasmacytic rhinitis/polyps
The most commonly identified non-infectious, non-neoplastic form of
(usually) bilateral nasal disease is lymphocytic or lymphoplasmacytic
rhinitis. This can appear as singular or multiple sessile mass-like or
polypoid lesions (Fig. 8.8a) or in the form of diffuse thickening and
erythema of the nasal mucosa (Fig. 8.8b). It is this author’s observation
that the ventral and middle nasal meati are most commonly involved,
but any portion of the rhinarium and paranasal sinuses can be affected.
This disease is thought to have an autoimmune underlying mechanism,
but environmental allergens are often implicated as either primary causes
or exacerbating factors in this disease.
For discrete masses or polyps surgery is often of benefit (see section
on laser rhinoscopic surgery, below) but recurrence is a concern regard-
less of the method of management. More diffuse presentations are usually
managed medically with corticosteroids being the therapy of choice. On
occasion oral antihistamines and/or non-steroidal anti-inflammatory
drugs are used with sporadic benefit. Occasionally, where environmental
or food allergens are implicated, hyposensitisation therapy can be con-
sidered. It is this author’s observation that frequently more potent immu-
nomodulatory medications (chlorambucil) are needed in conjunction
with steroids. Where bacterial infection is a secondary component,
appropriate antimicrobial therapy based on culture and sensitivity results
is indicated. Images of polyps are shown in Fig. 8.9.