Auer Ch 43 Nasal Passage & Paranasal Sinuses

Front 1

What are conchae?

Back 1

Two nasal conchae, which are scrolls of thin cartilage and bone, divide the nasal cavity into 4 meatus

Front 2

What are meatus?

Back 2

spaces between the conchae

Front 3

How many meatus?

Back 3

meatus are dorsal, middle, ventral and common

Front 4

Location of the dorsal meatus:

Back 4

between the roof of the nasal cavity and the dorsal concha

Front 5

Location of the middle meatus:

Back 5

between the dorsal and ventral concha

Front 6

Location of the ventral meatus:

Back 6

between the ventral concha and the floor of the nasal cavity

Front 7

Location of the dorsal concha?

Back 7

extends from the cribiform plate to the level of the first maxillary premolars

Front 8

Location of the ventral concha:

Back 8

extends from the levels of the last maxillary molars to the level of the first maxillary premolars

Front 9

Location of frontal and maxillary sinuses in relation to nasal cavity:

Back 9

located dorsal to and lateral to the nasal cavity

Front 10

Location of sphenopalatine sinus in relation to the nasal cavity:

Back 10

ventral

Front 11

Location of the dorsal, middle, and ventral conchal sinuses in relation to nasal cavity:

Back 11

caudal to the nasal cavity

Front 12

Communication of the sinuses with the nasal cavity:

Back 12

maxillary sinus is the only sinus that communicates directly with the nasal cavity, other sinuses communicate with the maxillary sinus

Front 13

Communication between the maxillary sinus and the nasal cavity:

Back 13

nasal maxillary opening

Front 14

Location of nasomaxillary opening:

Back 14

caudal aspect of the middle meatus

Front 15

How does the frontal sinus communicate with maxillary sinus?

Back 15

with the caudal maxillary sinus through the dorsally located frontomaxillary opening

Front 16

Location of frontomaxillary opening:

Back 16

level of the lacrimal canal and medial wall of the orbit

Front 17

How does the dorsal conchal sinus communication with the maxillary sinus?

Back 17

dorsal conchal sinus communicates openly with the frontal sinus, frontal sinus communicates with CMS via FMO

Front 18

What is the conchofrontal sinus?

Back 18

combined dorsal conchal and frontal sinus

Front 19

How does the sphenopalatine sinus communicate with the caudal maxillary sinus?

Back 19

over the infraorbital canal

Front 20

How does the ventral conchal sinus communicate with the maxillary sinus?

Back 20

over the rostral infraorbital canal within the RMS

Front 21

What tooth roots are associated with the maxillary sinus?

Back 21

root of the first molar (09) is within the rostral maxillary sinus and the roots of the second and third molars (10, 11) are within the caudal maxillary sinus

Front 22

Diseases of the nares:

Back 22

epidermal inclusion cysts and redundant alar folds

Front 23

How are epidermal inclusion cysts treated?

Back 23

removed by surgical incision of the cyst without penetration of the cyst, surgical removal after cyst drainage by use of a roaring burr, and injection of formalin into the cyst

Front 24

How are redundant alar folds verified to be the cause of poor performance or respiratory noise?

Back 24

by placing mattress sutures in the fold and tying them over the bridge of the nose and exercising the horse.

Front 25

How is surgical resection of the alar fold performed?

Back 25

through the nare or after excision of the lateral alar fold

Front 26

Advantages of nare approach to alar fold resection?

Back 26

more cosmetic

Front 27

Describe alar fold resection:

Back 27

dorsal or lateral recumbency, alar fold rostral to the alar cartilage is removed with a 2 cm section of the rostral end of the ventral concha. Hemostasis is achieved with primary closure of the incision

Front 28

Diseases of the nasal cavity:

Back 28

facial fractures, septal diseases and ethmoid hematomas

Front 29

Surgical treatment for septal diseases:

Back 29

Resection of the nasal septum can be partial, involving a small portion of the septum, or subtotal, involving a large portion of the septum

Front 30

Approaches to septal resection:

Back 30

through the lateral alae of the nostril for partial, rostral resections, through a trephination created dorsally at the caudal aspect of the septum, through a laryngotomy

Front 31

Desribe subtotal septal resection:

Back 31

septum is removed after incisions made dorsal, ventral and caudally using either an osteotome or obstetric wire

Front 32

Advantages of wire approach to subtotal septum resection:

Back 32

ventral incision removes more of the ventral aspect of the septum than the osteotome approach

Front 33

What delineates subtotal resection from a near total resection?

Back 33

Placement of Doyen intestinal forceps perpendicular to the ventral aspect of the nasal cavity is subtotal resection and placement of the forceps at a 60 degree angle directed caudoventral is a near total resection

Front 34

Advantages of laryngotomy approach to septal resection:

Back 34

better cosmetic outcome and less incisional complications than the trephine approach

Front 35

Intra-operative complications of septal resection:

Back 35

Hemorrhage

Front 36

Post-operative complications of septal resection:

Back 36

hemorrhage, airway obstruction

Front 37

Therapies directed at limiting post-operative complications of septal resection:

Back 37

controlled by packing the nasal cavity with gauze, tracheostomy placement

Front 38

Where can ethmoid hematomas develop?

Back 38

ethmoid labyrinth or within the paranasal sinus

Front 39

Composition of PEH:

Back 39

capsule is respiratory epithelium and fibrous tissue. The stroma is blood, fibrous tissue, and white blood cells

Front 40

Radiographic appearance of ethmoid hematomas?

Back 40

round density in the frontal or maxillary sinus, but can also have fluid lines or diffuse opacity of the sinus(es).

Front 41

How are PEH treated?

Back 41

Smaller lesions not involving the sinuses (<5 cm) can be ablated with a Ng:YAG laser or by injection of formalin, Larger masses or those in the sinus are removed through sinus flap approaches

Front 42

Disadvantages of formalin in treatment of PEH:

Back 42

requires many injections in 3-4 weeks intervals before regression occurs and is associated with rare risks such as laminitis, nasal obstruction, and necrosis of the cribiform plate

Front 43

What surgical approach is most versatile for removal of PEH?

Back 43

Frontonasal

Front 44

Intra-operative complication of surgical treatment of PEH:

Back 44

Hemorrhage

Front 45

Proposed ways of reducing hemorrhage during surgical removal of ethmoid hematoma:

Back 45

bilateral carotid artery ligation, gauze packing, epinephrine-soaked gauze packing, vascular clips, sterile saline ice slush instillation, and cryosurgery

Front 46

Diagnosis of sinus disease:

Back 46

radiography or other imaging, sinocentesis, and sinoscopy

Front 47

How is primary sinusitis differentiated from dental sinusitis radiographically?

Back 47

increased opacity of both the frontal and maxillary sinus is common in primary sinusitis but uncommon in dental sinusitis

Front 48

Disadvantages of rigid arthroscopic sinoscopy:

Back 48

multiple portals, has inconsistent visibility of the ventral conchal sinus and rostal maxillary sinus

Front 49

What does a frontal bone sinoscopy approach allows visualization of?

Back 49

conchofrontal and caudal maxillary sinus, ventral conchal and rostral maxillary, with fenestration of the ventral conchal bulla

Front 50

What should be performed if the VCB can not be visualized with the frontal sinoscopic approach?

Back 50

caudal maxillary approach

Front 51

Conchofrontal trephine site landmarks:

Back 51

60% of the distance from midline to the medial canthus of the eye, 5mm caudal to the medial canthus

Front 52

Caudal maxillary trephine site landmarks:

Back 52

2 cm rostral and 2 cm ventral to the medial canthus

Front 53

Rostral maxillary trephine site landmarks:

Back 53

40% of the distance from the rostral end of the facial crest to the level of the medial canthus, 1 cm ventral to a line joining the infraorbital canal and the medial canthus

Front 54

Modified frontonasal trephine approach landmarks:

Back 54

centered 5 cm dorsal to the medial canthus, 4 cm ventral (or lateral) to midline, and 2 cm ventral to the medial canthus

Front 55

How is the lacrimal duct identified?

Back 55

line from the medial canthus to the incisive notch

Front 56

How is primary sinusitis treated?

Back 56

systemic antibiotics and frequent lavage

Front 57

What should be considered if primary sinusitis does not resolve with treatment?

Back 57

dental origin should be re-investigated or the possibility of inspissated pus in the ventral conchal sinus exists

Front 58

Radiographic appearance of VCS sinusitis:

Back 58

soft tissue density over the roots of premolar 08 and molars 09-11, and narrowing of the nasal passage due to exudate

Front 59

How is the VCS accessed?

Back 59

Maxillary bone flap or trephination of the conchofronal sinus and fenestration of the ventral conchal bulla

Front 60

Causes of secondary sinusitis:

Back 60

dental disease, facial fractures, granulomatous lesions, and neoplasia

Front 61

Approach to sinus cysts removal:

Back 61

frontonasal or modified frontonasal bone flap

Front 62

Most common sinus neoplasia:

Back 62

squamous cell carcinoma

Front 63

What is considered before selection of trephination site in the maxillary sinus?

Back 63

Age. In younger horses, the alveoli of the caudal 3 molars are just below the infraorbital canal and make up the ventrolateral wall of the sinus

Front 64

Margins of maxillary bone flap:

Back 64

rostral is a line drawn from the rostral aspect of the facial crest to the infraorbital foramen, the dorsal margin is a line from the infraorbital foramen to the medial canthus, the caudal margin is a line parallel to the rostral margin, and the ventral margin is just dorsal and parallel to the facial crest

Front 65

Margins of frontonasal bone flap:

Back 65

caudal margin is a perpendicular line from midline to a point midway between the supraorbital foramen and the medial canthus, the lateral margin begins at the caudal margin, is within 2 to 2.5 cm of the medial canthus, and extends a distance 2/3 from the medial canthus to the infraorbital foramen, and the rostral margin is from the rostral aspect of the lateral margin, perpendicular to midline

Front 66

Describe bone flap:

Back 66

Skin incisions are made on the caudal, lateral, and rostral margins down to and including the periosteum. The osteotomy is made with a bone saw, a pneumatic drill with tapered burr, or an osteotome and mallet. The flap is created when the bone is elevated to fracture along the dorsal margin

Front 67

What can facilitate drainage into the nasal cavity with surgical access to the sinuses?

Back 67

creation of openings into the nasal cavity

Front 68

Where can openings into the nasal cavity be created during sinus surgery?

Back 68

Openings can be created through the dorsal concha and ventral concha. The region in the dorsal concha is identified by passing a mare catheter up the dorsal meatus, palpated through the sinus aspect of the concha. The ventral concha can be penetrated at 2 sites, in the rostral maxillary sinus over the infraorbital canal in younger horses, or ventral to the canal in older horses

Front 69

What treatment is performed after creation of nasal openings from the sinus?

Back 69

seton drain is placed and kept in place until the primary disease process has resolved, to ensure closure does not occur before resolution of disease

Front 70

Differential diagnoses are based on signs of persistent or intermittent epistaxis:

Back 70

PEH, rhinitis, neoplasia, guttural pouch mycosis or neoplasia, skull fracture, sinusitis, sinus cyst, or pulmonary diseases such as abscess, neoplasia or pleuropneumonia

Front 71

Examples of paranasal sinus disease:

Back 71

sinusitis, sinus cysts, and neoplasia

Front 72

what is endoturbinate 1?

Back 72

dorsal conchal sinus

Front 73

what is endoturbinate 2?

Back 73

middle conceal sinus

Front 74

paranasal sinuses:

Back 74

dorsal conchal, middle conceal, ventral conchal, sphenopalatine, frontal, maxillary