Page 64 - BSAVA Manual of Canine and Feline Head, Neck and Thoracic Surgery, 2nd Edition

Chapter 4 · Surgery of the nose and nasopharynx

Chronic rhinitis/sinusitis in cats radiotherapy protocol using cobalt (Adams et al., 1998;
Turek and Lana, 2013). Cytoreductive surgery performed
The specific aetiology of chronic rhinitis and sinusitis in
VetBooks.ir cats may vary. Viral infections (feline rhinotracheitis virus, significant postop erative complications can occur. These
after radiation therapy can improve survival; however,
feline calicivirus) are often initiating pathogens, although
are probably the result of radiation-induced poor tissue
bacterial infections may also be involved. Sinusitis may
be a primary problem. Viral, fungal, bacterial or lympho- healing (Turek and Lana, 2013). Occasionally, surgical
rhinotomy may be performed prior to radiation therapy to
plasmacytic sinusitis may be primary conditions or may
occur secondary to obstructive nasal disease. obtain a diagnostic biopsy sample.
Acute and late toxicities of radiotherapy have been
Cats with chronic rhinitis/sinusitis usually exhibit nasal
reported. Acute toxicity develops during treatment and
discharge with variable degrees of sneezing, anorexia,
gagging or vomiting. These clinical signs show a variable typically manifests as oral mucositis, keratoconjunctivitis
and blepharitis, rhinitis and skin desquamation (Theon et
response to antibiotics or anti-inflammatory doses of
steroids. The diagnosis is based on the results of biopsy, al., 1993; Adams et al., 1998; Lawrence et al., 2010). These
imaging studies (radiographs, CT, MRI) and rhinoscopy. effects normally resolve within 2–8 weeks after treatment
Treatment of chronic rhinitis/sinusitis is based on the (McEntee, 2006). Late toxicity is more serious and poten-
results of the biopsy and other diagnostic tests. tially very detrimental to the patient. It develops months
to years after treatment and is usually permanent. Late
Surgery is not recommended as an initial treatment for
chronic rhinitis unless a foreign body or a bony sequestrum effects include cataracts, keratoconjunctivitis sicca,
is present, or if polypoid/granulomatous changes are uveitis, retinal degeneration, brain necrosis, osteonecrosis
thought to be significantly reducing airflow. Ethmoid and skin fibrosis (LaDue et al., 1999; Gieger et al., 2008;
conchal curettage and placement of an autogenous fat McEntee, 2006; Lawrence et al., 2010).
graft to fill the sinus has been described (Tomlinson and If surgery is performed on a nasal tumour before or
Schenck, 1975; Anderson, 1987); however, the authors do after radiation therapy, the owners should be warned to
not recommend this technique. If an animal fails to respond expect life-long serous to mucoid nasal discharge post-
to medical therapy or suffers from severe nasal congestion operatively. There is also an increased risk of developing
as a result of polypoid deformation of the mucosal lining of opportunistic fungal or bacterial infection after radiation
the turbinates, surgical exploration of the frontal sinus and therapy and surgery, owing to the damage to tissues
nasal cavity and debridement of necrotic or diseased and blood supply. These patients routinely receive broad-
tissue should be considered. spectrum antibiotics for 3–4 months after surgery, and
nasal infections in these patients are challenging to treat.
Nasal neoplasia
Nasal neoplasia can be divided into neoplasia of the Stenotic nares
nasal planum or the rostral nasal septum and intranasal Stenotic nares are a congenital defect in the diameter of
neo plasia. Neoplasia of the nasal planum is rare in the the nares causing pathological resistance to airflow
dog and more common in the cat. Squamous cell carci- during nasal breathing in brachycephalic dogs. This is a
noma (SCC) is the most common tumour of the planum common component of the brachycephalic airway
and occurs secondary to effects of ultraviolet (UV) light disease. In -creased mucosal contact points, nasopharyn-
on unpigmented skin (Withrow, 2013). The biological geal turbinate protrusion, elongation of the soft palate,
behaviour of SCC can vary from local disease to highly hypoplastic trachea, secondary eversion of the laryngeal
invasive carcinomas. The treatment of choice for SCC is saccules and laryngeal collapse are other components of
nasal planum resection with or without radiation therapy this syndrome (Oechtering, 2010; Schuenemann and
(Holt et al., 1990; Cox et al., 1991). Reconstructive tech-
Oechtering, 2014a and b; Grosso et al., 2015). Stenotic
niques performed during wound closure can improve nares are less common in cats, but may occur in brachy-
the cosmetic outcome, but owners should be warned
cephalic cat breeds. Surgical correction of stenotic nares
that perfect cosmesis is not usually possible. Preven - is described in Chapter 6.
tive measures include tattooing a high-risk area of skin
or avoidance of UV light (indoor housing). Primary SCC
of the rostral nasal septum that is limited to the septum Nasal dermoid sinus
itself can be cured with full-thickness resection of
the septum using a combined rostrolateral rhinotomy A dermoid sinus (dermoid cyst, pilonidal sinus) is a con-
ap p roach (ter Haar and Hampel, 2015). genital abnormality caused by incomplete separation of
Intranasal neoplasms include carcinomas (about 66%) the ectodermal neural tube from the skin during embryo-
and sarcomas (about 33%) (Turek and Lana, 2013). These logical development. The condition is most commonly
tumours in general grow slowly, metastasize late in the seen along the neck and back in the Rhodesian
course of disease and occur more commonly in older Ridgeback but has been reported in other breeds. Nasal
animals. Tumour type is generally not prognostic; however, dermoid sinuses have been reported in the American
the stage of tumour does relate to prognosis (Turek and Cocker Spaniel, Springer Spaniel, Brittany Spaniel and
Lana, 2013). Golden Retriever (Anderson and White, 2002). The diag-
Treatment of intranasal tumours with cytoreductive nosis is suspected on the basis of a history of intermittent
surgery alone is not indicated. Cytoreductive surgery discharge from a small opening along the midline of the
alone or prior to megavoltage radiation therapy fails to bridge of the nose at a junction between the nasal planum
improve survival (MacEwen et al., 1977; Theon et al., 1993; and the skin (nasal pit) (Figure 4.12). The tract may extend
Adams et al., 1998), but radiation therapy delivered using into the cranial vault. Infusion of contrast medium into the
cobalt or a linear accelerator improves survival. A tract may help determine its caudal extent. Successful
censored median survival time of 19 months was reported treatment requires complete excision of the tract and
when nasal tumours were treated with an accelerated reconstruction of the defect.

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