Ch 99 Nasal and sinus

Question 1

anatomy

Answer 1

• 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

Question 2

What ligaments support the cartilages of the external nose?

Answer 2

Dorsal nasal ligament
Paired lateral nasal ligaments

Question 3

What muscles allow for movement of the external nose?

Answer 3

Levatro nasolabialis
Orbicularis oris
Levator labii maxillaries
Frontalis

innervated by the facial nerve.

Question 4

List the air passages of the nose

Answer 4

Dorsal, middle, ventral and common meatus

dorsal and larger ventral conchae define the air passages

Question 5

List the three paranasal sinuses

Answer 5

Maxillary recess
Shenoidal sinus
Frontal sinus - connected to nasal fossa via nasofrontal opening, through which an ethmoidal turbinate extends

Question 6

What are the bony walls of the rostral nasopharynx (choanae)

Answer 6

Hard palate ventrally
Vomer bone dorsally
Palatine bone laterally

Question 7

What is the mechanism of transmission of scent?

Answer 7

• 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

Question 8

What parts of the brain react to scent?

Answer 8

Olfactory bulb
Cadate nucleus activity when scent is associated with a positive or rewards in stimuli such as the owner

Question 9

What make the nose moist?
How does this contribute to defensive mechanisms?

Answer 9

Paired lateral nasal glands
Secretions contain immunoglobulin A

Question 10

diagnostic approach

Answer 10

• 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

Question 11

What are the top 2 DDx for intranasal mass lesions on advanced imaging?

Answer 11

Neoplasia
Fungal rhinitis (characteristic cavitary appearance)

Question 12

What anatomical features of the nasal cavity may be normal in cats but can often be mistaken for pathological?

Answer 12

• 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

Question 13

How does the diagnostic accuracy of blind nasal biopsy compare with rhinoscopic?

Answer 13

Not significantly different

Question 14

What breeds are predisposed to hereditary nasal parakeratosis and idiopathic depigmentation or vitiligo?

Answer 14

Hereditary nasal parakeratosis in Labs
Vitiligo in Rottweilers and Dobermans

Question 15

nasal planum neoplasia

Answer 15

Squamous cell carcinoma most common
lymphoma
malignant histiocytosis,
fibrosarcoma,
malignant melanoma,
lymphomatoid granulomatosi,
basal cell carcinoma,
fibroma
mast cell tumor
hemangiomas, hemangiosarcoma
eosinophilic granulomas

Question 16

SCC

Answer 16

• 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.

Question 17

What is the prognosis with nasal SCC?

Answer 17

Dogs:
- MST 12.5wk with Sx
- MST 26wk with radiation alone
- Recurrence 12/17

Cats:
- MST 12m
- Recurrence 3/8

Question 18

What is stenotic nares?

Answer 18

axial deviation of the dorsolateral nasal cartilage

Question 19

stenotic nares pathophys

Answer 19

• 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.

Question 20

What breeds are overrepresented with abberant conchae?
What are the common contact points?
What is the Tx option?

.

Answer 20

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)

Question 21

What is the most common nasal neoplasia of cats?
What is the MST?

Answer 21

Lymphoma
MST 98 days
- up to 45% of cats may have multiorgan involvement
- ddx adenocarcinoma, SCC, fibrosarcoma

Question 22

What is the most common nasal neoplasia in dogs?
What is the recommended Tx?
What is associated with a poorer prognosis?

Answer 22

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

Question 23

fungal

Answer 23

• 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

Question 24

ddx nsasl dz

Answer 24

• FB
• Idiopathic rhinitis
• nasal mites

Question 25

nasopharyngeal disease

Answer 25

- neoplasia was identified in 20 of 37 (54%) dogs - In cats, malignant and benign conditions are common

Question 26

Treatment of Nasopharyngeal Polyps

Answer 26

- 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

Question 27

What is choanal atresia? What are the Tx options?

Answer 27

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

Question 28

What is nasopharyngeal stenosis? What are the Tx options?

Answer 28

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

Question 29

Nasal Planum Excision

Answer 29

- 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 1. superficial lesions central planum, bilateral transposition flaps can be created from the ventral sulcus region of the nares 2. lip-to-nose > lateral half of the nose 2. purse-string suture > Second intention healing between the skin and nasal mucosa 3. musculofascial island labial flap 4. Bilateral, full-thickness labial advancement flaps 5. Labial Mucosal Inversion tehcnique AKA bilateral labial mucocutaneous rotation advancement flaps (Direct mucosal apposition leads to more direct wound healing, needs extensive bone removal

Question 30

stenotic nares

Answer 30

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

Question 31

What is the recommended settings when using a CO2 laser for treatment of stenotic nares?

Answer 31

Power setting 3-5 0.4mm fine tip Continuous waveform Frequent char removal

Question 32

What are the surgical options for stenotic nares?

Answer 32

* 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

Question 33

What is the reported reduction in airway resistance after laser-assisted turbinectomy?

Answer 33

50% in brachycephalic dogs

Question 34

Why is bilateral temporary carotid occlusion not recommended in cats?

Answer 34

They have a less robust cerebral blood supply and lack of internal carotid artery, increasing the risk of brain ischaemic damage

Question 35

List the approaches to the nasal cavity

Answer 35

Dorsal (most common for accessing nasal cavity and sinuses) Ventral (ventral nasal cavity, nasopharynx, ethmoid turbinates) Lateral Rostal/alveolar mucosal approach

Question 36

Ventral approaches should be used with caution in cats because.

Answer 36

use of mouth gags and prolonged maximal opening of the mouth can result in maxillary artery compression and subsequent cerebral and retinal ischemia.

Question 37

Dorsal Approach to the Frontal Sinus and the Nasal Cavity

Answer 37

- 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.

Question 38

Ventral Approach to the Nasopharynx or rhinotomy

Answer 38

- 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

Question 39

What is ventral rhinotomy relatively contraindicated in young animals?

Answer 39

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

Question 40

Postoperative Considerations and Complications

Answer 40

- 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.

Question 41

What complications have been reported after rhinotomy if the cribiform plate is damaged?

Answer 41

* Ventricular pneumocephalus * Septic meningoencephalitis

Question 42

Sinusotomy

Answer 42

- 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.

Question 43

Nasopharyngeal stenosis in cats: a retrospective study of 21 cases comparing endoscopic and surgical treatment (2018–2022) Champetier 2024

Answer 43

retrospective Nasopharyngeal stenosis in 21cats. Dx endoscopy and CT 12 > endoscopic balloon dilation; 11 cases demonstrated a complete resolution 8 > extended palatoplasty, seven cases complete resolution success rate was not different between techniques. The outcome for Tx caudal or imperforate NPS: successful (78%) No complications. imperforate NPS > lower success rate for balloon dilation

Question 44

Comparison of the effectiveness of three different rhinoplasty techniques to correct stenotic nostrils using silicone models: A case study Franklin 2024

Answer 44

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

Question 45

Successful correction of stenotic nares using combined Alar Fold Lift-Up and Sulcus Pull-Down Techniques in brachycephalic cats: 8 cases (2017–2022) Pavletic 2023

Answer 45

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

Question 46

Ala vestibuloplasty improves cardiopulmonary and activity-related parameters in brachycephalic cats Gleason 2023

Answer 46

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

Question 47

Application of a bilateral temporal fascia free graft in a dog with multifragmented frontal sinus and nasal bone fracture dunand 2022

Answer 47

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

Question 48

Prognostic factors for cats with squamous cell carcinoma of the nasal planum following high-dose rate brachytherapy Lino 2019

Answer 48

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.

Question 49

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%)

Question 50

Single pedicle advancement flap for treatment of feline stenotic nares: technique and results in five cases Chanel N Berns 2019

Answer 50

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

Question 51

Question 52

Dorsal offset rhinoplasty for treatment of stenotic nares in 34 brachycephalic dogs Vanna M. Dickerson 2020

Answer 52

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

Question 53

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

Answer 53

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

Question 54

Objective effectiveness of and indications for laser-assisted turbinectomy in brachycephalic obstructive airway syndrome Nai-Chieh Liu 2019

Answer 54

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

Question 55

Outcome following cosmetic rostral nasal reconstruction after planectomy in 26 dogs VannaM. Dickerson | bilateral labial mucocutaneous rotation advancement flaps

Answer 55

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

Question 56

Inside the Brachycephalic Nose: Conchal Regrowth and Mucosal Contact Points After Laser-Assisted Turbinectomy schuenemann 2014 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.