Ch 99 Nasal and sinus Flashcards
anatomy
- divided longitudinally by the nasal septum into two nasal fossae.
- The nasal planum
- philtrum
- nostrils open into the nasal vestibule
- external nose is supported by a paired, symmetric, cartilaginous frame
- cartilages of the external nose are supported by several ligaments
What ligaments support the cartilages of the external nose?
Dorsal nasal ligament
Paired lateral nasal ligaments
What muscles allow for movement of the external nose?
Levatro nasolabialis
Orbicularis oris
Levator labii maxillaries
Frontalis
innervated by the facial nerve.
List the air passages of the nose
Dorsal, middle, ventral and common meatus
dorsal and larger ventral conchae define the air passages
List the three paranasal sinuses
Maxillary recess
Shenoidal sinus
Frontal sinus - connected to nasal fossa via nasofrontal opening, through which an ethmoidal turbinate extends
What are the bony walls of the rostral nasopharynx (choanae)
Hard palate ventrally
Vomer bone dorsally
Palatine bone laterally
What is the mechanism of transmission of scent?
- Odorant substances bind to receptor proteins on surface of cilia arising from olfactory cells
- G-protein coupled transmembrane protein mechanism causes transmembrane Na-channel opening and influx of intracellular Na
- Creates an action potention in olfactory nerves
What parts of the brain react to scent?
Olfactory bulb
Cadate nucleus activity when scent is associated with a positive or rewards in stimuli such as the owner
What make the nose moist?
How does this contribute to defensive mechanisms?
Paired lateral nasal glands
Secretions contain immunoglobulin A
diagnostic approach
- ddx neoplasia (adenocarcinoma, squamous cell carcinoma, lymphoma, and others), inflammatory polyp, fungal, viral, bacterial, foreign body, dental disease, and idiopathic rhinosinusitis.
- historical and clinical features are highly overlapping
RADs
- intraoral dorsoventral and open-mouth ventrodorsal, rostrocaudal frontal sinus projection.
- greatest predictive value for diagnosis of nasal neoplasia was destruction of surrounding bones
CT
- better able to differentiate rhinitis from neoplasia.
- inflammatory mass fails to enhance in postcontrast imaging sequences
- Nasopharyngeal polyps: isoattenuating to adjacent muscles and hypoattenuating to adjacent soft tissues
- nondestructive, bilateral nasal mucosal thickening = inflammatory rhinitis.
Rhinoscopy and Nasopharyngoscopy
- allows direct observation and it facilitates collection of directed samples.
- perform retroflexed choanal and nasopharyngeal examination before rhinoscopic examination to avoid blood, mucus, or flush (can’t see this area on rhinoscope)
- Nasal tumors typically appear as obstructive gray to white soft tissue masses
biopsy/samples
- cytologic evaluation > flush, swab, brush, fine needle aspirate
- accuracy of cytology results variable
- histopathologic evaluation may be collected blindly using cup or alligator forceps (distance from the nares to the medial canthus should be measured)
- Antigen serology for Cryptococcus spp. in cats is highly sensitive and specific
- Routine bacterial culture is seldom informative in nasal disease
What are the top 2 DDx for intranasal mass lesions on advanced imaging?
Neoplasia
Fungal rhinitis (characteristic cavitary appearance)
What anatomical features of the nasal cavity may be normal in cats but can often be mistaken for pathological?
- Deviation of the septum
- Sinus asymmetry
- Signifcance of septal lysis or cribiform lysis is predictive of neoplasia in dogs but the significance of these findings in cats is debated
How does the diagnostic accuracy of blind nasal biopsy compare with rhinoscopic?
Not significantly different
What breeds are predisposed to hereditary nasal parakeratosis and idiopathic depigmentation or vitiligo?
Hereditary nasal parakeratosis in Labs
Vitiligo in Rottweilers and Dobermans
nasal planum neoplasia
Squamous cell carcinoma most common
lymphoma
malignant histiocytosis,
fibrosarcoma,
malignant melanoma,
lymphomatoid granulomatosi,
basal cell carcinoma,
fibroma
mast cell tumor
hemangiomas, hemangiosarcoma
eosinophilic granulomas
SCC
- locally invasive malignancy that invades adjoining soft tissue and bone
- exposure to sunlight likely plays a role in the malignant transformation
- Complete surgical resection is the treatment of choice for squamous cell carcinoma
- Survival times are short because these tumors can be quite invasive and obtaining adequate surgical margins is difficult
- adjuvant treatment therapies may be required.
What is the prognosis with nasal SCC?
Dogs:
- MST 12.5wk with Sx
- MST 26wk with radiation alone
- Recurrence 12/17
Cats:
- MST 12m
- Recurrence 3/8
What is stenotic nares?
axial deviation of the dorsolateral nasal cartilage
stenotic nares pathophys
- results in significant upper airway obstruction > theorized to precede and instigate BOAS
- Significant negative pressure must be created in the lumen of the lower airways and larynx to overcome the upper airway obstruction
- This negative intraluminal pressure results in supraphysiologic stress on the laryngeal and tracheal soft tissue and cartilage.
- result in tissue edema, collapse of laryngeal cartilages, and further obstruction of airflow.
What breeds are overrepresented with abberant conchae?
What are the common contact points?
What is the Tx option?
.
Frenchies and Pugs
Aberrant conchae arose either rostrally or caudally and tended to have abnormal branching and crude lamellae.
- intraconchal and septoconchal
- Diode laser-assisted turbinectomy (regrowth is common but with significantly fewer contact points)
What is the most common nasal neoplasia of cats?
What is the MST?
Lymphoma
MST 98 days
- up to 45% of cats may have multiorgan involvement
- ddx adenocarcinoma, SCC, fibrosarcoma
What is the most common nasal neoplasia in dogs?
What is the recommended Tx?
What is associated with a poorer prognosis?
Adenocarcinoma - locally aggressive (rate of metastasis is low)
- Radiation is Tx of choice.
- Cytoreductive surgery does not improve outcome. MST 8-19m
- survival times were not improved by postradiation nasal exenteration
- Involvement of cribiform plate associated with shorter MST 6.7m
ddx SCC, sracoma, round cell
fungal
- most common fungal pathogen of the nose of dogs is Aspergillus fumigatus
- destructive rhinitis, which can be difficult to distinguish from nasal neoplasia
- young, large-breed dogs
- in cats, Cryptococcus neoformans
treatment of Fungal Rhinosinusitis
- systemic antifungal therapy does not achieve adequate penetration
- traditional: trephination of the sinuses and nasal cavity for placement of catheters and infusion of either low-dose enilconazole daily for 7 to 10 days or high-dose clotrimazole once under anesthesia
- noninvasive technique (better distribution): occlusion of the nasopharynx and nares and placement of infusion catheters into the nasal cavity via the nares
- outcome: majority of dogs (65%) treated by either surgically placed or noninvasively placed infusion catheters are cured after the first infusion; overall, 87% of dogs are cured with repeated (up to four) infusions
- enilconazole: cure within two treatments
rhinotomy or sinusotomy
- Purported advantages include:
- visual inspection of healing tissues,
- physical application of topical antimicrobial to lesions to ensure complete coverage and potentially decrease the quantity of medication needed
- continued opportunity for debridement
- Highly invasive > best reserved for unusually difficult cases
ddx nsasl dz
- FB
- Idiopathic rhinitis
- nasal mites
nasopharyngeal disease
- neoplasia was identified in 20 of 37 (54%) dogs
- In cats, malignant and benign conditions are common
Treatment of Nasopharyngeal Polyps
- arising from the mucosa of the auditory tube, middle ear, or nasopharynx. Inflammatory polyps may also commonly occur in the external ear canal
- the cause is unknown; congenital and infectious causes
Tx
- treated with traction-avulsion (recurrence 1/12)
- received prednisolone after traction-avulsion but did recur in 9 of 14 cats (64%) that did not receive prednisolone
- Most or all of the stalk associated with the polyp will also be removed from the auditory tube, as long as the polyp is retracted with gentle steady pressure
- may result in Horner’s syndrome or vestibular signs
- midline incision in the soft palate
What is choanal atresia?
What are the Tx options?
Congenital condition in which the oronasal membrane fails to resorb. May be partial or complete, osseous or membranous
- Balloon dilatation or open excision and reconstruction
What is nasopharyngeal stenosis?
What are the Tx options?
An acquired condition resulting from nasopharyngeal inflammation (i.e. post Sx, truama, infection) resulting in a varibale thick, impenetrable membrance partially or completely occluding the nasopharynx
Tx options:
- Open surgical resection (restenosis has been reported)
- Endoscopic-guided balloon dilatation (membranous and under 5mm thick)
- Stenting (covered for complete stenosis, uncovered for partial)
- Restenosis in up to 35%, oronasal fistula, stent migration
Nasal Planum Excision
- adequate counseling and client communication before surgery are essential because of significant aesthetic changes
- complete staging should be performed
- bilateral blocks of the infraorbital nerves
- intraoperative blood loss may be significant > paired dorsal and lateral nasal arteries and the major palatine arteries
- Complete excision may require resection of the incisive bone and rostral aspects of the nasal bone and maxilla
- superficial lesions central planum, bilateral transposition flaps can be created from the ventral sulcus region of the nares
- lip-to-nose > lateral half of the nose
- purse-string suture > Second intention healing between the skin and nasal mucosa
- musculofascial island labial flap
- Bilateral, full-thickness labial advancement flaps
- Labial Mucosal Inversion tehcnique AKA bilateral labial mucocutaneous rotation advancement flaps (Direct mucosal apposition leads to more direct wound healing, needs extensive bone removal
stenotic nares
scalpel blade, laser, or electrosurgery can be used for tissue incision
- Improper technique > excessive carbonization may prolong wound healing or the presence of depigmented scar tissue
- Closure can be performed with 4-0 or 5-0 monofilament
What is the recommended settings when using a CO2 laser for treatment of stenotic nares?
Power setting 3-5
0.4mm fine tip
Continuous waveform
Frequent char removal
What are the surgical options for stenotic nares?
- Amputation of ventral portion of dorsolateral nasal cartilage (“Traders technique”)
- Lateral, vertical, or horizontal wedge resection > and there modification
- 2-6mm punch biopsy
- Alapexy
dorsolateral aspect of the wing of the nostril
What is the reported reduction in airway resistance after laser-assisted turbinectomy?
50% in brachycephalic dogs
Why is bilateral temporary carotid occlusion not recommended in cats?
They have a less robust cerebral blood supply and lack of internal carotid artery, increasing the risk of brain ischaemic damage
List the approaches to the nasal cavity
Dorsal (most common for accessing nasal cavity and sinuses)
Ventral (ventral nasal cavity, nasopharynx, ethmoid turbinates)
Lateral
Rostal/alveolar mucosal approach
Ventral approaches should be used with caution in cats because.
use of mouth gags and prolonged maximal opening of the mouth can result in maxillary artery compression and subsequent cerebral and retinal ischemia.
Dorsal Approach to the Frontal Sinus and the Nasal Cavity
- If the sinuses are also being explored, this incision should extend caudal to the zygomatic crests of the frontal bone
- periosteum are elevated
- An initial opening is made with a hand chuck and intramedullary pin or with a burr
- osteotome and mallet, sagittal saw, or small burr can be used to create the window.
Ventral Approach to the Nasopharynx or rhinotomy
- The soft palate is incised on the longitudinal midline through the oral mucosa, palatinus muscle, and nasopharyngeal mucosa.91 The caudal margin of the soft palate is left intact to facilitate accurate closure and reduce tension on the sutured wound;
- caudal margin of the hard palate may be removed
- Electrocautery should be avoided or used sparingly to maximize healing.
- A three-layer closure is used for the soft palate (nasopharyngeal mucosa, muscular layer, and oropharyngeal mucosa).
- A ventral rhinotomy, however, requires the incision to continue or be located more rostrally
- Subperiosteal elevation is performed laterally with care to preserve the major palatine arteries
- bone is not replaced at closure
- Oronasal fistula formation may be complication
What is ventral rhinotomy relatively contraindicated in young animals?
Can alter the growth of the muzzle
- Dogs - damage to vomer bone may alter muzzle growth
- Cats - transverse palatal length can be retarded after damage to vomer bone but sagittal length is preserved
Postoperative Considerations and Complications
- Before extubation, gauze sponges, blood clots, and debris should be removed
- atient’s head should be kept slightly lower than the thoracic inlet to reduce the chance of aspiration
- Hemorrhage from the nares may continue for several days after surgery (consider packing for 24hr)
- Subcutaneous emphysema
- Chronic serous discharge is frequently encountered after removal of nasal turbinates.
What complications have been reported after rhinotomy if the cribiform plate is damaged?
- Ventricular pneumocephalus
- Septic meningoencephalitis
Sinusotomy
- appropriate site for sinusotomy should be confirmed with preoperative imaging
- level with the zygomatic process of the frontal bone > Removal of the frontal bone and caudal nasal bone, exposing the frontal sinuses
trephine
- alternative, may be used to establish a port for tissue biopsies, bacterial or fungal culture, sinuscopy, or drain placement.
- landmarks include the orbital rim ventrally, the zygomatic process of the frontal bone laterally, and the midline of the skull medially, forming a triangle where the sinus is entered.
Nasopharyngeal stenosis in cats:
a retrospective study of 21 cases
comparing endoscopic and surgical
treatment (2018–2022)
Champetier 2024
Diagnosis was based on endoscopy (21 cases) and CT (19 cases).
12 cases were treated with endoscopic
balloon dilation; 11 cases demonstrated a complete resolution
Eight cats were treated surgically (including one cat that was originally treated with balloon dilation), including seven cases
with complete resolution of clinical signs
success rate was not different between the
endoscopic (11/12) and surgically treated cases (7/8) (P = 0.85). The outcome was considered excellent in most
of the cases as 18/23 procedures were successful (78%)
No complications directly related to the procedures were reported.
seven cases treated with extended palatoplasty
surgical palatoplasty offers
a safe and successful alternative for caudal or imperforate NPS; therefore, stents should probably be reserved for salvage procedures
imperforate NPS, which seems to be associated with a lower success rate for balloon dilation
Comparison of the effectiveness of three different
rhinoplasty techniques to correct stenotic nostrils
using silicone models: A case study
Franklin 2024
Ninety-nine 3D-printed, remolded silicone models of a
single French bulldog’s rostral nose.
underwent either vertical wedge resection (VW), modified horizontal
wedge resection (MHW), or ala-vestibuloplasty (AVP) performed by a single
surgeon (n = 33 per group).
CT scans of the models were performed, and CSAs of the airway
Average percentage increases in CSA were 26%, 15% and 74%,
Ala-vestibuloplasty resulted in a larger increase in the airway
CSA of silicone modeled nares and nasal vestibules
contribSuccessful
correction of stenotic nares using combined Alar Fold Lift-Up and Sulcus Pull-Down Techniques
in brachycephalic cats: 8 cases (2017–2022)
Pavletic 2023
Successful correction of the stenotic nares was achieved, enabling each cat to breathe normally
Surgery is restricted to the adjacent skin and does not require the surgical alteration of the external nose or nares
Ala vestibuloplasty improves cardiopulmonary and
activity-related parameters in brachycephalic cats
Gleason 2023
Study design: Prospective cohort.
Animals: Client-owned BC cats (n = 19).
No complications occurred during surgery
Cats were reevaluated at a mean of 11 weeks (range; 8-20 weeks) postoperatively.
No complications occurred following discharge
Pulmonary blood flow and respiratory
function were improved after surgery.
Although cats in this study exhibited similar clinical
signs to BC dogs, stenotic nares were the primary and
often only anatomic contributors to BC syndrome
Application of a bilateral temporal fascia free graft in a dog
with multifragmented frontal sinus and nasal bone fracture
The integrity of the frontal and nasal cavities, and the facial profile of
the dog were restored. No short-term or long-term complications were
observed after 4 months follow up
innovative combination of suture
apposition of bone fragments and a temporal fascia free
graft resulted in excellent long-term outcomes
Prognostic factors for cats
with squamous cell carcinoma
of the nasal planum following
high-dose rate brachytherapy
Lino
Complete response was achieved in 72% (n = 36) of the cats, partial response in 24% (n = 13) and
2% (n = 1) did not respond. Median progression-free survival and overall survival times were 316 and 835 days,
respectively.
Burdick 2018 – interventional treatment for benign nasopharyngeal stenosis and imperforate nasopharynx
- balloon dilation: 5 dogs, 22 cats; success: 0/5 dogs, 11/22 (50%) cats
- stenting: uncovered: 30/34 (including 15 unsuccessful balloon); success 20/30 (67%)
covered: 11/34 (including 7 unsuccessful uncovered); success 11/11
- complications: 23/34 (68%)
- uncovered: tissue ingrowth (10/30), chronic infection (7/30), stent fracture (5/30)
- covered: chronic infection (8/11), oronasal fistula (3/11)
- outcome: successful 36/46 (78%)
Single pedicle advancement flap for
treatment of feline stenotic nares:
technique and results in five cases
Chanel N Berns 2019
All cats had positive outcomes, resulting in immediate reduction of the nasal fold and opening of the nares.
Owners noted resolution of stertor and no episodes of respiratory distress. No surgical complications were reported
Dorsal offset rhinoplasty for treatment of stenotic nares
in 34 brachycephalic dogs
Vanna M. Dickerson 2020
Thirty-four dogs met the inclusion criteria. Twenty-nine (85%) dogs
were examined a median of 402.5 days (range, 23-2042) postoperatively, with
no major complications related to the rhinoplasty recorded
One owner
reported that self-trauma led to collapse of one naris. One owner reported collapse
of both nares within 4 years;
Previous rhinoplasty techniques have focused on lateral opening of the nares on the median plane
Opening of the nares in
the dorsal plane may allow more airflow through the
ventral meatus within the nasal passages
Lip-to-nose flap for reconstruction of the nasal planum
after curative intent excision of squamous cell carcinoma in
cats: Description of technique and outcome in seven cases
Massari 2020
Postoperatively, six cats developed selflimiting
edema of the muzzle, and one cat had nasal discharge for 2 days. No
major complications occurred during the healing process
A small area of partial-thickness
necrosis developed at the cranial edge of the flap in three cats
Median duration of follow-up was 485 days (range,
274-1275). At the end of the study, all cats were alive
without signs of recurrence
Objective effectiveness of and indications for laser-assisted
turbinectomy in brachycephalic obstructive airway syndrome
Nai-Chieh Liu 2019
Prospective clinical study.
Sample population: Client-owned pugs, French bulldogs, and English bulldogs
(n = 57).
BOAS index was obtained from whole-body barometric plethysmography
Dogs with BOAS index >50% and BOAS functional grades II-III after CMS
were considered candidates for LATE. A BOAS index was repeated 2–6 months
after LATE.
Twenty-nine of 57 dogs were candidates for LATE
The median BOAS index of dogs that were operated on
(20/29 candidates) decreased from 67% post-CMS to 42% after LATE
Computed tomography-based measurement of rostral entrance of choanae can be used to predict whether LATE is required in addition to CMS in pugs and French
bulldogs with BOAS.
discrepancies in surgical outcome among
studies could reflect different surgical techniques, patient
populations, and the subjectivity of evaluating the surgical
outcome.
objective measurements
were unsatisfactory in 50% of dogs after CMS.
need long study to assess for regrowth
Outcome following cosmetic rostral nasal reconstruction after planectomy in 26 dogs
VannaM. Dickerson
bilateral labial mucocutaneous rotation advancement flaps
Complications occurred in 19 (73%) dogs, with 9 dogs requiring revision
surgery; 1 dog not surviving to discharge. Median survival time was 1542 days (range,
3-2010). Recurrence of the primary tumor was suspected in 2 (7.7%) dogs, both with
narrow or incomplete excision.
Dehiscence was common after this procedure, but local tumor control
and survival times were excellent
Inside the Brachycephalic Nose: Conchal
Regrowth and Mucosal Contact Points After
Laser-Assisted Turbinectomy
At 6 mo, 96% of FBs’ and
65% of pugs’ nasal cavities showed regrowth of turbinates. FBs showed higher growth grades than pugs. Revision surgery
because of reobstructing regrowth was required in the nasal cavities of 17% of FBs and 3% of pugs. The mean number of
contact points reduced from 3.0 in FB and 1.7 in pugs before surgery to 1.2 in FB and 0.2 in pugs after conchal regrowth.
