Page 60 - BSAVA Manual of Canine and Feline Head, Neck and Thoracic Surgery, 2nd Edition

Chapter 4 · Surgery of the nose and nasopharynx

of the imaging modality and pertinent anatomy. Biopsy temporary unilateral or bilateral occlusion of the common
instruments can be directed through the nares, through the carotid artery can be performed following rhinotomy to
VetBooks.ir initial attempts at biopsy fail to provide a definitive diag- cavity can be packed with sterile moistened umbilical tape
reduce blood loss.
soft palate or laterally through areas of bony destruction. If
If haemorrhage persists after turbinectomy, the nasal
nosis, an open biopsy (rhinotomy) should be considered.
A thorough oral examination with dental probing guided
secured to the skin with suture. Nasal packing is usually
by imaging results should be performed under general prior to closure. The packing should exit the nostril and be
anaesthesia in cases where chronic rhinitis is found with no left in place for 24 hours. Removal of packing material can
obvious abnormalities on rhinoscopy. Abnor malities such usually be done in an awake or sedated animal, and the
as oronasal fistulae and cleft palate may be identified material should be removed rapidly to minimize discomfort
during visual and digital examination of the palate and to the patient.
nasopharynx. Probing of periapical alveolar pockets of
especially the canine teeth is essential in diagnosing oro- Dorsal rhinotomy
nasal fistulation, even in cases where there are no apparent
dental abnormalities. Mass lesions in the nasopharynx can This is the most common approach to the nasal cavity.
The technique provides unilateral or bilateral access to the
be sampled either using endoscopic biopsy forceps or
nasal cavity and can be extended caudally to expose
following rostral traction on the soft palate to expose the the frontal sinuses (see Operative Technique 4.1). A uni-
mass. In addition, fine-needle aspirates can be obtained by
lateral dorsal rhinotomy can also be performed more
probing through the soft palate into the suspected mass. laterally if indicated.
Alternatively, it may be necessary to incise the soft palate A dorsal midline incision is made through the skin and
on the midline to biopsy or remove masses from the naso-
periosteum from just above the level of the eyes to the
pharynx. Closure is performed in two or three layers with nasal cartilages, and the periosteum is reflected laterally
small-gauge (1–2 metric (3/0–5/0 USP)) absorbable suture
over the nasal bone. The limits of a bone flap are iden tified,
material in a continuous pattern to avoid placement of and the bone flap is removed with rongeurs, an oscillating
excessive knots in the tissues.
saw, air-powered burr or an osteotome. There appears to
be no increase in complications or reduction in cosmesis
when the bone flap is not replaced. If the bone flap is going
Surgical techniques to be returned following surgery, osteo tome bone cuts are
recommended because there is little loss of bone, and the
flap returns to a near normal position. If the flap is to be
Rhinotomy replaced after surgery, it is hinged on its most rostral
Indications for rhinotomy include biopsy, debridement of attachment to the cartilage. Complete removal of the bone
necrotic tissue, exploration for chronic nasal discharge is especially useful in cats and small dogs because the flap
with unknown aetiology, removal of nasal foreign bodies, is quite small. If radiation therapy will be performed after
cytoreduction of nasal masses (as discussed previously) surgery, removal of the bone flap is recommended. The
and flushing mucus or fungal balls. Most surgeons prefer a flap is often devitalized by the radiation and may have to be
dorsal approach to the nasal cavity and paranasal sinuses, removed during a second surgery.
because of enhanced accessibility to the cribriform plate Following exposure, the nasal cavity is gently explored.
and frontal sinuses, but ventral rhinotomy may be indicated If the turbinates are damaged they are usually removed.
in selected patients with focal abnormalities in the ventral Biopsy specimens and samples for culture are taken as
meatus, choana and/or nasopharynx. A lateral rhinotomy is needed, and haemorrhage is controlled as discussed
indicated in those instances where access is only required previously. If the bone flap is replaced, small holes are
drilled in the four corners of the flap and the corresponding
to the rostral part of the nasal cavity (nasal vestibule)
(Hedlund, 1998, 2007; ter Haar and Hampel, 2015). areas of the skull, and surgical steel wire or heavy non-
absorbable suture material is used to attach the flap. The
Haemorrhage should be anticipated when performing a
rhinotomy. Efficient surgical technique is paramount periosteum and subcutaneous tissues are closed with small
to reduce blood loss. The more rapidly and efficiently the (1–1.5 metric (4/0–5/0 USP)) absorbable suture material in
a continuous pattern, and the skin is closed routinely.
surgery is performed, the less likely it is that haemorrhage
will become a major problem. Electrocautery should be Postoperative haemorrhage is a relatively common
complication. The haemorrhage is usually mild to moderate
used judiciously, especially if a ventral rhino tomy is being
performed. Compression can be applied to the operative and should resolve if coagulation function is normal. Ice
field with sponges or laparotomy pads to control haemor- packing of the muzzle may facilitate vasoconstriction and
reduce haemorrhage as well as provide some analgesia.
rhage during surgery. When working caudally the rostral
nasal cavity is packed, and vice versa. Flushing with cold In rare cases where the haemorrhage is severe or
prolonged, the animal may need to be returned to surgery
saline or diluted (1:100,000) adrenaline (epinephrine) will
cause local vasoconstriction and reduce surface bleeding. to pack the nasal cavity. Subcutaneous emphysema is
another possible complication following surgery, but is rare
This dilution of adrenaline rarely causes systemic effects,
if proper airflow through the nasal passages is restored
unless an overwhelming volume is used; however, the during surgery and the periosteum is tightly sutured. There
patient should be care fully monitored for development of
is little consequence of this complication, but it requires
cardiac arrhythmias. Bone wax can be used to occlude several weeks to resolve completely. As mentioned earlier,
intraosseous haemorrhage. If the spheno palatine arteries persistent nasal discharge is common after rhinotomy,
can be identified and ligated, haemorrhage can be
especially if the turbinates were removed.
reduced. Performing temporary occlusion of the carotid
arteries prior to rhino tomy may minimize haemorrhage and
improve visual zation during turbinectomy (Hedlund et al., Ventral rhinotomy
i
1983). If temporary carotid artery occlusion has not been A ventral approach for rhinotomy has also been described
performed preoperatively and severe haemorrhage occurs, (Holmberg et al., 1989). Advantages of ventral rhinotomy
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