Nasal Disease: Recognition and Diagnosis Flashcards
Common nasal dx of canine and feline ? (5)
neoplasia,
rhinitis,
foreign bodies,
fungal infections,
polyps
What are the nasal cavities separated by?
Nasal septum
What structure marks the start of the nasopahrynx?
Choanea
Nasal fossa:
A) What is it divided by?
B) Divided into? (2)
A) Dorsal concha; curved shelf of bone originating from the ethmoidal crest
B) Dorsal meatus and the middle meatus
Nasal fossae:
A) What does the ventral nasal concha extend from?
B) What does concha divide the nasal cavity into?
A) Conchal crest
B) middle meatus and ventral meatus before forming the alar fold rostrally
Ethmoturbinates:
A) Caudally; where to they extended from?
B) and to?
A) the midline ethmoidal plate
B) Cribiform plate
Ethmoturbinates:
What sinuses are they present in?
Presphenoid
Frontal sinus
How can ethmoturbinates be sub divided? (2)
long, medially lying endoturbinates
smaller, more superficial ectoturbinates.
Nasopharygeal meatus:
What is it formed by? (3)
The confluence of the caudal ends of the dorsal, middle and ventral meatuses
Where does the nasopharyngeal meastus run to?
Choanea
Nasal planum
A) Epitheliea type?
pigmented and consists of tough, thickened keratinized squamous epithelium.
The external nares are supported by (4)
Dorsolateral cartilage,
ventrolateral cartilage,
accessory cartilage
cartilaginous septum
What is the largest of the nasal cartilages and merges with the ventral nasal concha?
The dorsolateral cartilage
Where are The olfactory receptors are located mainly?
ethmoturbinates and thus are in the caudodorsal section of the nasal cavity.
Nasal mucosa:
The blood supply originates from the maxillary artery that arborises into (2,1)
sphenopalatine and major palatine branches before continuing as the infraorbital artery
What supplies the nasal conchae, and its terminal branches are known as the caudal lateral nasal arteries
The sphenopalatine artery
Lymphatic drainage of nasal mucosa? (3)
retropharyngeal,
parotid
submandibular lymph nodes.
Clinical signs of nasal disease (9)
sneezing,
stertor,
nasal discharge,
epiphora,
epistaxis,
inappetence,
sleep disorders,
dyspnoea
facial swelling or distortion
A careful history is useful and should include: (5)
progression of clinical signs
response to previous treatments
outdoor exposure and environment
vaccination status
contact with other household or cattery cats.
What areas of CE should be focussed on with nasal dx? (6)
- Teeth
- Larynx ausc
- Nasal airflow
- Epiphora - fluoro
- Assymetry
- Nasal planum
Why use fluorecein dye for epiphora?
Assess nasolacrimal duct
Diagnostic tests for nasal dx after CE? (3)
blood profiles including coagulation profiles (and ideally FeLV/FIV status)
imaging including rhinoscopy if available
culture and histology.
Which biopsy techniques might commonly be required in cases of nasal disease? (4)
Rhinoscope
Blind biopsy
Nasal flush
Trephination though the maxillary bone
Rhinoscope, size for:
A) Small dog/cat
B) Dog?
A) 1.9
B) 2.7
Rhinoscope; what to do to a haemorrhaging biopsy site to take more samples?
flushed with cold isotonic fluid
How to perform a larger biopsy with rhinoscope?
A pair of crocodile or cup forceps can also be passed parallel to the scope
What should be performed before performing a blind biopsy? Why?
advanced imaging should ideally be used to locate the approximate area of disease
How to avoid cribiform plate damage when performing blind biopsies?
A pair of crocodile or cup forceps is measured from the nares to the medial canthus of the eye and a piece of tape placed at this level to avoid damage to the cribriform plate
Possible tools for blind biopsies? (3)
- Crocodile
- Stylet
- 16-gauge catheter with an end that is cut obliquely attached to a 10 ml syringe to apply negative pressure to the sample
Nasal flush:
A) How?
B) Syringe size?
C) Repeat?
A) high pressure saline being flushed through the nares whilst the other nostril is digitally occluded
B) 20 ml syringe
C) 2-3 times
What is the risk if the cribiform plate is damaged?
Cerebral damage
If repeated nasal biopsies have failed to yield a diagnostic result, any mass lesion seen on imaging can be biopsied via?
trephination through the maxillary bone
Maxillary trephination:
After making a small skin incision, the bone is perforated with a A) (2) of large enough diameter to allow B) to be passed into the nasal cavity
A) Michel’s trephine or K wire
B) crocodile forceps
Maxillary trephination is rarely necessary but can be useful for?
tumours originating from the maxillary sinus.
Nasal sampling - haemorrhage is expected; what should therefore happen?
pharynx should be packed with a conform bandage or large swab (dog)
Ventral approach to the nasal cavity. Pros (1)
Good cosmetic results
Ventral approach to the nasal cavity. cons (1)
Limited access for instruments and ET tube
Dorsal approach to the nasal cavity
Pros (1)
Good access
Dorsal approach to the nasal cavity
Cons (2)
poor cosmetic appearance
subcutaneous emphysema.
Pre-op prep for nasal surgery? (4)
- Blood profiles and coagulation profiles or at minimum a BMBT
- +/- Temporary carotid ligation
- Blood available if necessary
- Arterial blood pressure monitoring
Ventral Rhinotomy
Position?
Dorsal recumbency with the head secured in a level position with tape around the maxillary canines.
Ventral Rhinotomy
If the oral cavity is compromised by the presence of an endotracheal tube what should be placed?
a guarded pharyngostomy tube
How to place a guarded pharyngostomy tube? (incision site, intrument)
Small skin incision caudal to hyoid apparatus onto the point of some large forceps such as Rochester-Carmalt - bring the tube into the pharynx. It is then retroflexed into the trachea.
During a ventral rhinotomy, what happens to the pharynx?
Pack with a swab
Ventral rhinotomy:
Where is the palate incision?
The palate is then incised over the midline from the level of the canine teeth to the fourth premolars.
During palate incisions, electro-coagulation should be used sparingly - T or F
True
Ventral rhinotomy:
- What is elevated to expose the palatine bone?
The mucoperiosteum
What runs alongside the dental arcade from the carnassial tooth? (Which you need to take care to avoid in ventral rhinotomy).
Major palatine a.
If a large exposure is needed with ventral rhinotomy, what can be used?
A hinged mucoperiosteal flap of palate is raised and retracted
During a ventral rhinotomy, what is used to access the nasal cavity?
A burr is then used to gently burr through the palatine bone
If a burr isnt available for a ventral rhinotomy how can you access?
Two holes can be made with K-wires and then connected with rongeurs which can then be used to enlarge the cavity.
What is used in a ventral rhinotomy to decrease haemorrhage and increase visualisation?
Ice saline
How to close a ventral rhinotomynmucoperiosteum layer?material (2), number of layers, pattern)
Relatively long-lasting suture material e.g. polydiaxonone or glycomer 631
single layer
simple interrupted suture.
How many and name the layers of closure of the soft palate.
3
- nasal mucosa,
- palatine subcutaneous tissue + muscles
- oral mucosa
Which animals should a ventral rhinotomy be avoided in and why?
skeletally immature dogs - affect the development of the muzzle
Dorsal Rhinotomy:
Position?
The patient is placed in sternal recumbency, with the nose positioned level on a sandbag. The pharynx is packed with a swab or bandage.
Dorsal Rhinotomy
Where is the initial incision?
A midline incision is made from the medial canthus of the eye rostrally over the nasal bone.
Dorsal Rhinotomy:
The skin and periosteum are elevated and retracted by (2)
Stay sutures
Gelpi retractors
Dorsal Rhinotomy:
How to control haemorrhage?
- Bipolar electro-coagulation
- Swab pressure
Dorsal Rhinotomy:
How to get through the nasal bone and access nasal cavity?
Burr
Dorsal Rhinotomy:
How to access nasal cavity if no burr available? (2)
- Two holes can be made with K-wires and then connected with rongeurs
- An air saw can be used to cut a rectangular flap of bone
Use of an air saw for dorsal rhinotomy is difficult in cats; why?
Confined incisional area
Best suture material for closure of the periosteum in a dorsal rhinotomy?
polydioxanone or glycomer 631
What layers are closed in a dorsal rhinotomy?
- Periosteum
- Mucosa
- Skin
How to ensure drainage of S/C air accumulating with a dorsal rhinotomy/prevent emphysema? (3)
- A small piece of sterile tube is sutured into the wound dorsally connecting the nasal cavity with the air to act as a drain
- A small gap is left at the dorsal aspect of the incision (can occlude)
- Tie on bandage
Post rhinotomy; what position to recover in?
Head down
Post rhinotomy; after removing throat pack, check the pharynx for..?
Blood clots
Post rhinotomy; what to use if there is ongoing haemorrhage? (2)
- Nasal tampons/pack nose
- Adrenaline (vasoconstrict)
Post rhinotomy; why are they commonly anorexic? (4)
temporary disruption of the normal sense of smell
stress,
discomfort
medications
What food to offer post rhinotomy?
Soft + pungent
Post rhinotomy - restrict what toys?
Hard/chew
What do you need to assist cats with post rhinotomy?
Grooming
If the drain becomes occluded in a dorsal rhinotomy and subcutaneous emphysema occurs this is usually self-resolving in?
7- 10days
Rhinotomy complications (5)
- Bleeding
- Sneezing (can lead to epistaxis)
- Anorexia
- Subcut emphysema
- Dehiscence
