ENT and Upper Airway Surgery

Ear, Nose and Throat

As the middle ear is directly connected to the nasopharynx by the eustacian tubes, ear conditions are included with upper airway, i.e. the nose and nasopharynx.

Ears are prone to both medical and surgical problems. In many cases disease can be controlled at an early stage preventing progression to a stage where surgery is necessary. Skin disease affecting the ear lining allows infection to become established resulting in inflammation and pain, and the tissues alter narrowing the ear canals trapping infection and discharges deep in the canal and middle ear.

Once things have progressed this much, surgical removal of the ear canal is likley to be the best approach. Although there are frequent complications with major ear surgery, these are mostly minor and/or short term.

X-rays show changes when these are significant. Here there is bone destruction affecting the tympanic bulla on teh right. Whilst this can be due to infection, it can also be caused by a tumour.

Three dimensional imaging is very helpful in establishing the extent of changes. The MRI image at the right shows extensive inflammation (the white area on the left of teh image) caused by persistent infection despite appropriate previous surgery. In cases like this additional surgery needs to be much more aggressive so nerve damage and inner ear complications are likely.

Inner ear inflammation is present in most cases if infection has spread to the middle ear. Balance disturbance and deafness are common and can be (usually temporarily) exacerbated by medical or surgical intervention. Like facial nerve paralysis, another complication of ear disease and its treatment, most problems resolve once treatment has been copmpleted and healing is progressing.

Ventral bulla osteotomy.
This procedure is mostly required for treatment of polyps in cats.

Airways

Breathing requires the presence of a route for air to pass from the nostrils or mouth to the lungs. The nose, nasopharynx, larynx and first part of the trachea make up the upper airways. These are prone to a wide range of medical and surgical conditions. Some lower airway conditions are mentioned on the Thoracic surgery and Airway Medicine pages.

Nasal problems

The shape of many breeds of animals, particularly those with short noses, leads to narrowing and distortion of the upper airways. When the nostrils are too narrow they require widening or if they are involved in developmental clefts (right) they need to be repaired, as do injuries to this area.

Surgical reconstruction of congenital deformities is typically complicated by absence of normal tissue beneath the obvious lesion as shown in the x-ray here.

The new left nostril is slightly deformed and a scar is visible but there is no connection between the nose and oral cavity so long term nasal complications are minimised and the dog can lead a normal life.

Foriegn bodies such as this stick are commonly found as causes of nasal problems in young dogs. Luckily it was possible to remove this one endoscopically, but some become firmly lodges requiring a full surgical approacf for removal..

One of the more unpleasant problems seen in the nose is fungal infection caused by Aspergillus species. These eventually cause a lot of inflammation and damage (RHS of CT scan image). Diagnosis at as early a stage as shown to the left is currently difficult so the infection is often well established by the time it can be confirmed.

Because fungal infections are difficult to treat surgical access used to be necessary for placement of a treatment tube in the frontal sinuses so that the medication could be administered directly into the nose and sinuses twice daily for 5-7 days. Newer medication have reduced the need for this relatively invassive treatment, but the drugs still have to be applied into the sinuses, though this can now usually be done using needles placed during anaesthesia. The treatment takes just over an hour and the needles are removed before the patient wakes up. Using this technique most cases can be cured with two treatments about 2 weeks apart.

Whilst there are some nasal tumours that are amenable to surgical management, most are not, in which case chemotherapy or radiotherapy may be recommended providing the problem has not spread too far.

The nasopharynx

The nasal cavities exit into the nasopharynx behind the soft palate. Foreign bodies, injuroies, developmental cysts and abnormalities of the soft palate can all interfere with airflow in this region. In mild cases the results may just be snoring, but any restriction of airflow at this lavel can lead to problems deeper in the airways. The picture here shows an uncommon "functional soft palate cleft" abnormality that is the result of failure of some of teh soft palate muscles to form.

Diagnosis is difficult due to the normal appearance of the resting soft palate.

The most common surgery in this region is shortening of overlong soft palates. Developmental cleft soft and hard palate occur intermittently. The resulting hole allows food and drink thorugh from the oral cavity into the nose which becomes inflamed.

The larynx

Laryngeal injuries are seen less frequently than developmental abnormalities and degenerative conditions. Brachycephalic (short nosed) dogs often have hypoplastic larynx and trachea in addition to their general upper airway obstruction. They are particularly probe to laryngeal oedema, everson of laryngeal saccules and laryngeal collapse which can present as emergencies. Other breeds often develop laryngeal paralysis as they get older causing difficulties in breathing, particularly in warm conditions.

Laryngeal paralysis without collapse responds well to surgery to fix one or both vocal cords to the side, opening the airway. Lartyngeal collapse is more difficuult to treat, but again, surgery is usually beneficial. Laryngeal oedema is likley to require a tracheostomy for immediate relief. When upper airway obstruction cannot be corrected a permanent tracheostomy may be the only ) treatment option.

The trachea

Tracheal injuries may be repaired surgically and tumours removed using open or endoscopic surgery. There is little that can be done for a hypoplastic (developmentally narrow) trachea, but the degenerative problem 'tracheal collapse' has several surgical options. These do not correct the problem just reduce its effects. Complications are common and often severe with conventional surgery so when there are no complicating factors placement of an intratracheal stent is often recommended.

A self expanding metalic stent

Before and after stent placement for treatment of tracheal collapse

Use of stents allows a return to a near normal lifestyle for the majority of patients, but the treatment is only palliative and progression of the underlying problem can extend into the lower airways which cannot currently be treated effectively.