Small Animal Soft Tissue Surgery: Nasal Disease, URT Disease Flashcards
What clinical signs will an animal with chronic nasal disease present with?
Sneezing
Snoring or increased respiratory noise
Nasal discharge
Epistaxis- nose bleed
Facial pain
What are some common causes of acute nasal disease?
Nasal foreign body: in cats and dogs, often present with paroxysmal sneezing and facial irritation
Viral upper respiratory tract infection (in cats)
Allergic/irritant rhinitis
Tooth root abscesses: can present as nasal discharge if they rupture internally into the nasal cavity
What can cause chronic nasal disease?
- Any cause of acute nasal disease if not treated
- Feline rhinotracheitis: commenest cause of chronic rhinitis in cats
- Neoplasia
- Fungal rhintis- aspergillosis in dogs, cryptococcosis in cats
- Lymphocytic/plasmacytic rhinitis
Describe how to do a clinical exam for the investiagation of nasal disease
- Visually inspect head from front and above for asymmetry
- Assess the nares and nasal planum for discharge, crusting, ulceration or depigmentation
- Palpate the maxilla, zygomatic are and frontal bones for pain, swelling or soft areas (these may be associated with lysis of the underlying bone)
- Retropulse both globes- inability indicates a space occupying lesion in the retrobulbar space
- Assess nasal air flow with beice of fabric or hair infront of nare
- Examine the oral cavity for evidence of dental disease, oronasal fistulae, palate defects or ventral deviation of the palate
- Palpate the submandibular lymph nodes
What diagnostic blood tests can be done for the investigation of nasal disease?
Blood tests
- Routine haematology and biochemistry screens to look for evidence of systemic disease
- Clotting profile if epistaxis is the only clinical sign, has been severe of there is evidence of haemorrhage
- Serological testinc gor aspergillus fumigatus and cryptococcus neoformans
How can virology of nasal diseases be tested?
Conjuntival, nasal or pharyngeal swabs
What different kinds of imaging can be used for investigation of nasal disease?
Radiography- lateral radiographs, dorsoventral intraoral views and the rostrocaudal view are most useful- dental may be necessary, thoracic to look for metastases
Advanced imaging- computed tomography is used extensively for diagnosis as it avoids the difficulty of interpreting radiographs of the skull and nasal cavity
How is rhinoscopy performed and what can it diagnose?
Both nasal cavities can be examined with rigid or flexible endoscopy
Can show mucosal lesions, masses and foreign bodies
Flexible endoscopy can also be used to examine the nasopharnyx and choanae by retroflexing endocscope around the caudal end of the soft palate
How can a nasal biopsy be performed?
If been done blind where should not be biopsied?
Can be performed blind or with rhinoscopic guidance, perform a clotting profile as biopsy will cause haemorrhage
Rhinoscopid- with flexible endoscope and biopsy forceps passed through the rhinoscope or rigid cup
Same forceps for blind biopsy but no not biopsy caudal to medial canthus of the eye to avoid damage to the cribriform plate
What should be done if haemorrhage after nasal biopsy is prolonged?
If is prolonged or severe you can flush the nasal cavity with ice-cold saline or place an icepack on the maxilla on the affected side to cause vasocontrcition
Or pack the nasal cavity with gauze
What can fine needle aspiration, nasal swabs and exploratory rhinotomy be used for in diagnosis of nasal disease?
FNA- aspirate the mandibular and/or retrophargeal lymphnodes if they are enlarged or firm
Nasal swabs- bacterial culture and sensitivity testing and cytology
Exploratory rhinotomy is the last resort
What fungi usually cause fungal rhinosinusitis in cats and dogs?
What signalment is common?
What are the clinical signs?
Fungi- aspergillus fumigatus infection in dogs, fungal rhinitis rare in cats usually cyptococcus neoformans
Signalment- usually young to middle aged medium or large breed dogs
Clinical signs- causes extensive damage to turbinates:
- Nasal discharge- usually mucopurulent, epistaxis is frequent finding
- Facial pain
- Ulceration and depigmentation of the nasal planum
- Dullness and depression
How is fungal rhinosinustis diagnosed?
- History and clinical signs
- Serology- false negatives are frequent, fale positives will occur
- Radiography- show destruction of the turbinate bones with increased radioleucencty and increased fluid density in the nasal cavity due to disdharge
- CT- more sensitive for detection of destructive rhinitis
- Rhinoscopy- reveals turbinate destruction and possibly visible fungal plaques and allows biopsies
- Histopathology- identification of fungal hyphae in nasal biopsies is the gold standard for diagnosis of funcal rhinitis
How is fungal rhinosinusitis treated?
Oral antifungals are largely ineffective- requiring several month of therapy with only an approximate 50% cure rate
Topical treatment is most successful:
Trepination of the frontal sinuses and flushing with sterile saline followed by packing of the sinuses/nasal cavity with clotrimazole cream
Non-invasive smoking of the nasal cavity with clotrimazole soultion via catheters placed in the nasal cavity with foley catheters used to block the nares and nasopharnx to allow retention of the liquid
What tumours often infected the nasal cavity?
A variety of mostly malignant tumours may affect the nasal cavity
Adenocarcinoma, oteosarcoma, squamous cell carcinoma, fibrosarcoma and lymphoma
What is the normal signalment and clinical signs of nasal neoplasia?
Signalment- usually older medium or large breed dogs
Clinical signs
- Reduced nasal airflow
- Nasal discharge
- Facial swelling or distorsion
- Palate welling or distorsion
- Exopthalmos due to invasion into the retrobulbar space
- Neurological signs due to extension through the cribform plate
How is nasal neoplasia diagnosed?
- History and clinical signs
- Diagnostic imaging: radiography or CT may reveal a soft tissue/fluid density mass in the nasal cavity, turbinate destruction or lysis of the nasal septum, palate or maxilla
- Rhinoscopy and biopsy: take care when obtaining biopsies that you take a large enough sample to ensure you do not biopsy only the normal mucosa overlying the mass
How is nasal neoplasia treated?
Radiation therapy is the most effective treatmenr for most nasal tumours although it usually only extends the animals survival time/improves quality of life rather than being curative
Chemotherapy for nasal lymphoma
Palliative treatment with antibacterials, analgesics and anti-inflammatories if other treatments are not available or declined by owner
What is non-infectious inflammatory rhinitis also known as?
Lymphocytic or plasmacytic rhinits
How is non-infectious inflammatory rhinitis diagnosed?
History and clinical signs
Diagnostic imaging: radiography or computed topography may reveal mild tubrinate loss and increased soft tissue density due to discharge in the nasal cavity
Rhinoscopy and biopsy will allow histopathological diagnosis of lymphocytic/plasmactic infilatration of nasal mucosa, possibly with eosinophils and secondary bacterial infection and neutrophilic inflammation
How is lymphocytic inflammatory rhintis treated?
Rarely cured, often long term combination of:
- Environmental modification: minimisation of exposure to possible allergens or irritants by ventilation, humidifying and cleaning
- Instillation of saline into the nares to liquifty and clear nasal passage
- Intermittent nasal flushes
- Anti-inflammatories
- Antibacterials
- Mucolytics
- Testing for and eliminiation of environmental or dietary allergens may be useful
What are the clinical signs of a nasal foreign body?
How is it diagnosed?
Clinical signs
- Sudden onset
- Sneezing
- Distress
- Eventually may cause purulent discharge
Diagnosis
- History and clinical signs
- Rhinoscopy
- Diagnostic imaging- radiography or computed tomography may reveal the foreign body- chronic localised destructive rhinitis
- Exploratory rhinotomy
How are nasal foreign bodies treated?
Nasal flushing to dislodge the foreign body
Pack the common pharynx with swabs and examine them for foreign body post-flushing
Endoscopic removal
Rostral retraction of the soft palate and retrieval with forceps for glass blades in cats
Rhinotomy if the above is not successful
How can dental disease be diagnosed and treated?
Perform a throrough dental examination under anaesthesia in nasal discharge cases
Affected patients usually middle aged or older
Extraction of affected teeth with concurrent antibiotic therapy is usually curative
What is usually the cause of bacterial rhinitis?
Primary bacterial rhinits is rare in cats and dogs- usually secondary to another nasal disease
Nasal flushed rarely offer diagnostic value
What is a rhinotomy?
What different approaches are used?
Surgical exploration of the nasal cavity-
dorsal and ventral approaches are described for removal of foreign bodies, masses or tubinectomy for treatment of refractory rhinitis
Dorsal approach can be extended caudally to give access to the frontal sinuses
Why are rhinotomy surgerys often the last option for nasal disease?
Rhinotomy risks significant complications including life threatening haemorrhage
Application of a tourniquet or ligation of the common carotid may be neccessary
Whole blood should be available to transfuse the patient if required
What is BOS?
Brachycephalic obstructive airyway syndrome
What are the primary components of BOS?
What does this lead to?
Primary components-
- Overlong soft palate
- Stenotic nares
- Tracheal and laryngeal hypoplasia
Causes upper airway obstruction, increased respiratory effort and marked negatvie pharyngeal and laryngeal pressures on inspiration
What are the secondary changes of BOS?
Tonsillar enlargment/protrusion of tonsils from crypts
Laryngeal collapse- eversion of the laryngeal sacules
Tracheal collapse
All further restrict airflow
What are the clinical signs of BOS?
- Marked inspiratory noise- stertor
- Dyspnoea and increased respiratory effort
- Snoring or sleep apnoea
- Excercise intolerance
- Cyanosis
- Fainting or collapse
- Gagging or dysphagia
- Regurgitation
- Cough, dullness, pyrexia in patients with secondary aspiration pneumonia
How is BOS diagnosed?
Breed, history and clinical signs
Examination of the airway under ligh anaesthesia to assess:
- Tonsil size and protrusion
- Soft palate- just overlap the tip of the epiglottis
- Larynx- look for laryngeal collapse
Radiography to assess:
- Pharyngeal airway
- Tracheal diameter
- Presence of signs of aspiration pneumonia
- Other causes of airway obstruction
How can BOS be treated?
All dogs of the affected breeds have this condition to some degree: surgery depends on clinical signs and the impact on the animals quality of life
Ideally surgery in early animals life
Rhinoplasty
Palatoplasty
Laryngeal sacculectomy
Tonsillectomy
How can an dog with BOS be stabilised in an emergency?
Place patient in a cool, quiet environment
Give supplementary oxygen (mask, nasal catheter)
Sedate if pateint very stressed
Administer short activing corticosteroids
Be prepared to intubate if necessart to bypass obstruction
How can rhinoplasty be performed for treatment of BOS?
Lateral, vertical or horizontal wedge resection of the dorsal lateral nasal cartilages
Size the wedge based on the degree of enlargment of the nostril required and extend it deeply enough into the cartilage to adequately open the nares
Control haemorrhage by closing the defect with 2 metric absorbable sutures
How can palatoplasty be used to treat BOS?
Give short acting IV corticosteroids to reduce post op swelling
Position patient in sternal recumbancy with upper jaw suspended to open the mouth
Resect the excess soft palate using scissors or a tissue sealing device so that the remaining soft palate just overlaps the tip of the epiglottis
How is a laryngeal sacculectomy performed to treat BOS?
Grasp the everted laryngeal saccule mucosa with long handled forceps and amputate it level with laryngeal mucosa using metzembaum scissors
Arrest any haemorrhage with several minutes of gentle pressure using a sterile cotton bud or swab
When is a tonsillectomy performed for treatment of BOS?
Often alongside rhinoplasty/palatoplasty/laryngeal sacculectomy
What is laryngeal collapse?
What are the 3 grades?
Develops usually due to secondary to chronic upper airwat obstruction that causes increased airway resistance leading to chondromalacia and collapse of the larynx
stage 1- eversion of the laryngeal saccules
Stage 2- eversion of the laryngeal saccules and medial deviation of the cuneiform process of the arytenoids
Stage 3- eversion of the laryngeal saccules and medial deviation of the cuneiform and corniculate processes of the arytenoid cartilages
How is laryngeal collapse treated?
Stage 1- laryngeal sacculectomy
Stage 2/3- laryngeal sacculectomy +/- arytenoid caudolateralisation
Permanent tracheostomy is an alternative to above treatment
What is arytenoid caudolateralisation
What is laryngeal paralysis?
During normal inspiration the dorsal cricoarytenoid muscle contracts- causing abduction of the arytenoid cartilages and opening the glottis. Paralysis of the dorsal cricoarytenoid results in reduced size of the glottis and increased airway resistance during inspiration
What can cause laryngeal paralysis?
Congenital dysfunction of the recurrent laryngeal nerve
Idiopathic degeneratoin of the recurrent laryngeal nerve
Generalised neuropathy due to metabolis disease
Generalised myopathies
Damage due to trauma, neoplasia
Most cases are idiopathic and the paralysis is usualyl unilateral
Which breeds are predisposed to acquired laryngeal paralysis?
- Golden retrivers
- Labroadors
- Irish setters
- Afghan hounds
Rare in cats
What are the clinical signs of laryngeal paralysis?
Inspiratory stridor
Excercise intollerance
Fainting or collapse
Altered phonation
Cough or gagging during swallowing
Dysphagia if the recurrent paraoesophageal nerve is also affected
How is laryngeal paralysis diagnosed?
- History and clinical signs
- Laryngoscopy under light anaesthesia with patient in sternal recumbancy and assistant holding head in a natural position
- Thoracic and cervial radiography- mass lesions and concurrent pneumonia
- Routine haematology, biochem and thyroid function to rule out metabolic disease
- Electromyography and/or nerve/muscle biopsies if you suspect a generalisted neuropathy or myopathy
- Edrophonium response testing if you suspect myasthenia gravis
How is laryngeal paralysis treated?
Most commonly is arytenoid lateralisation (laryngeal tieback) suture is used to replace function of the dorsal cricoarytenoid, permanently abduction the arytenoid cartilage
In a laryngeal ties back why is surgery performed unilaterally on the left?
Surgery on the left is easier for a right-handed surgeon- not you sausage
Unilateral lateralisation provides an adequate airway in the majority of cases
Bilateral lateralisation massively increases the incidence of postoperative aspiration pneumonia
What are the possible complications of a arytenoid lateralisation?
Aspiration pneumonia
Failiure of the tieback due to suture or cartilage breakage
Seroma and development of other signs of generalised neuropathy
Generalised weakness or dysphagia
Investigation of tracheal disease
How can diagnostic imaging be used to investigate tracheal disease?
Radiography or CT will show many tracheal abnormalities- collapse or stenosis due to excellent contrast- inspiration and expiration images required
Fluoroscopy allows a dynamic study in a conscious patient but increases radiation exposure for patient and staff
How can trahceobronchoscopy be used to investigate tracheal disease?
Allows examination of the trachea throughout the respiratory cycle
Obstruction due to the endoscope may compromise ventilation- important with patients with tracheal disease
Biopsy can be done during tracheobronchoscopy
What can a bacterial wash be used for, for investigation of tracheal disease?
Lavage for bacterial culture and sensitivity testing
What can cause tracheal tears?
What do small and large tracheal tears cause?
Sharp penetrating- cervical bite wounds
Blunt trauma- choke train injuries
In cats- over inflation of cuffed endotracheal tubes
Turning of patient without disconnecting the tube
Small tears may be subclinical- peritracheal empysema or pneumomediastinum
Larger tears will result in subcutaneous emphysema or pneumothorax
How are tracheal tears treated?
- Conservative treatment with cage rest if patient no dysponeic
- If there is severe and unresolving subcutaneous empysema or patient dyspnoeic perform a tracheoscopy to identify, expose, debride and suture tear with 1-2 metric monofilament absorbable suture material
What is trachea avulsion?
Complete severance of the intrathoracic trachea
Usually 1-4cm cranial to tracheal bifurcation
How is tracheal avulsion diagnosed?
History of trauma and progressive dyspnoea
Tracheostomy reveals circumferential tracheal ring disruption or tracheal stenosis depending on chronicity of condition
Thoracic radiography reveals an intrathoracic pseudotrachea
How is tracheal avulsion treated?
Debride and anastomose the avulsed ends of the trachea
Consider referral
Repair is ususally successful and long term prognosis good
What causes tracheal collapse and how is it graded?
Laxity of the trachealis muscle and chondromalacia of the tracheal rings leads to progressive dorsoventral collapse of the tracheal lumen.
Graded I-IV
- I- laxity of the dorsal tracheal membrane resulting in 25% collapse of the lumen
- II- loss of cartilage rigidity and further laxity of the membrane resulting in 50% collapse of the lumen
- III- flattening of the tracheal cartilages resulting in 75% collapse of the lumen
- IV- further collapse of the rings resulting in 100% loss of luminal integrity
Why is tracheal collapse classed as dynamic?
Cervical trachea collapses on inspiration
Intrathoracic trachea collapsing on expiration
What is the common signalment and clinical signs of tracheal collapse?
Signalment:
Usually middle aged minature of toy breeds
Pomeranians, yorkshire terriers, chihuahuas, minature/toy poodles
Clinical signs:
- Cough- usually distinctive goose honk
- Waxing and waning dyspnoea
- Excercise intolerance
- Cyanosis
- Flattening of the cervical trachea on palpation
How is tracheal collapse diagnosed?
- Signalment, history and clinical signs
- Examination of the upper airway under GA to rule out obstruction
- Fluoroscopy may reveal changes in tracheal lumen diameter during inspiration and expiration
- Radiography- lateral views of cervical region and thorax during inspirationa and expiration to rule out cardiac/lower airway disease
- Tracheoscopy- to accurately determine the location and grade of collapse and assess for bronchial collapse
- Bronchioalveolar lavage to rule out lower airway disease
How is tracheal collapse treated?
The vast majority of dogs wull respond for more than 12 months to appropriate medical managment:
- Weight loss if required
- Avoid stress, exitement, vigorous excercise and heat
- Use a harness rather than a collar and lead
- Address any coexisting upper and lower airwat disease
- Corticosteroids for short courses and at the lowest dose possible that controls clinical signs
- Antitussives- co-phenotrope or codeine
- Bronchodilators- reduce intrathoracic pressure
- Antibacterials to treat any concurrent infection
If tracheal collapse cannot be treated with medical managment how can it be treated surgically?
What are the problems with the potential options?
Intraluminal stenting with a self-expanding woven or laser cut stent
Extraluminal stenting with prostetic rings- usually only the cervical trachea is stented
Intraliminal stenting- usually good outcome, there is usually ongoing medical treatment after, complications- stent migration/fracture, faulre of stent to integrate into tracheal mucosa resulting in reduced mucociliary clearance leading to tracheal stenosis and collapse of unstented trachea
Extraluminal- tracheal necrosis associated with the disruption of blood supply, persistent coughing, collapse of unstented portion
What is tracheal hypoplasia?
What breeds is it commonly seeen in?
How is it diagnosed?
Incomplete development of the trachea
Most commonly seen in brachycephalic dogs
Diagnosed by lateral cervical and thoracic radiographs
How is tracheal hypoplasia treated?
Surgical managment of other airway abnormalities- stenotic nares, overlong soft palate, everted laryngeal saccules
Symptomatic treatment to improve mucociliary clearance- bronchodilators, mucolytics and intermittend antibacterial treatment
What is tracheal stenosis and how is it diagnosed and treated?
Abnormal narrowing due to trauma (penetration injuries, blunt trauma, surgery) and excessive granulation tissue fortmation- patients present with progressive cough, excercise intollerence and dyspnoea due to airway obstruction
Diagnosis:
- History and clinical signs
- Diagnostic imaging
- Tracheoscopy and biopsy
Treatment- tracheal resection and anastomosis
What are the clinical signs and diagnosis for tracheal neoplasia the same as?
Tracheal stenosis
How is tracheal neoplasia treated?
Surgical excision and anastomosis for small, minimally invasive tumours
Chemotherapy and possibly radiotherapy for lymphoma
How can the cervical trachea and the start of the thoracic trachea be accessed?
Access the cervical trachea via a ventral midline cervical skin incision, seperating the sternohyoideus muscles along the midline to reveal trachea, first part of thoracic can be revealed by gentle cranial retraction of the trachea or extend the approach into a cranial median sternotomy
Other then the first part, how can the thoracic trachea be accessed?
Via right 3rd to 5th intercostal space thoracotomy depending on the level of the lesion
What important structures need to be avoided?
What should be done id the trachea is injured?
Trachea has segmental blood supply from the cranial and caudal thyroid and bronchoesophageal arteries so as little dissection as possible should be performed
Other important structures- recurrent laryngeal nerves, carotid arteries, thyroid glands, jugular veins
Tracheal injuries and incisions should be closed with monofilament absorbable suture material
When is a temporary tracheostomy indicated?
Indicated to relieve existing or potential life-threatening upper respiratory tract obstruction or for access to the trachea for ventilatory assistance
Removal of secretions and aspirated material
Inhalational anesthesia for upper respiratory or intraoral surgery
Describe the technique of temporary tracheostomy
- Position patient in dorsal recumbancy with neck extended over a pad
- Incise skin along ventral midline for 8-10cm caudal from the larynx and seperate the right and left sternothyroid and sternohyoid muscles to expose trachea
- Make a transverse incision through the annular ligament between the 4th and 5th tracheal rings, ensuring you do not incise more than 50% of the tracheal circumference
- Place a loop of monofilament nonabsorbable suture around the tracheal ring cranial and caudal to the incision to facilitate handling and access for placement of the tracheotomy
- Place a non-cuffed tracheostomy tube into the tracheal lumen, the external diameter of the tube should not exceed 75% of the tracheal lumen diameter
- Suture the skin cranial and caudal to the tracheostomy site- leave sufficient size to allow access for replacing the tube
- Coat the surrounding skin with antibacterial ointment and lightly bandage the neck to protect stoma
How is a temporary tracheostomy tube maintained?
- Exchange the tube for a fresh one at least twice a day- clean and disinfect before re-use
- Suctioning the airway as often as required
- Moisurising the airway by either nebulising the patient or instilling 0.2ml/kg saline through the tube every 1-4 hours
What are the complications of tracheostomies?
- Tube obstruction or removal
- Gagging/coughing
- Subcutaneous emphysema, pneumomediastinum, pneumothorax
- Infection
- Tracheal stenosis
How is a tracheostomy tube removed?
Removed when inciting cause of the respiratory obstruction is resolved
Occlude the tube and stoma for 15-20 mins with an occlusive dressing before removal to ensure patient does not suffer respiratory distress
Stoma can heal by second intention with apporpriate wound managment and dressing changes
How does a permanent tracheostomy vary to a temporary?
Creation of permanent stoma to manage unresolvable URT obstruction
A section of tracheal wall 4-6th rings is removed and tracheal mucosa sutured to the skin
Long term care inclused cleaning the opening, trimming surrounding hair, maintaining appropriate body condition, restricting swimming
When is a tracheal resection indicated?
Tracheal stenosis
Localised neoplasia
Tracheal granuloma
