Paranasal Sinuses Flashcards
What are the main paranasal sinuses of a horse?
Frontal Sinus
Dorsal Conchal Sinus
Dorsal conchal bulla
Ventral conchal bulla
Caudal Maxillary Sinus
Rostra Maxillary Sinus
Which of the main sinuses communicate?
Frontal, Dorsoconhcal and caudal Maxillary, sphenopalantine
Rostral maxillary and ventral conchal
Separated by bulla
Where is the nasomaxillary aperture/Sinus drainage angle?
Where the nasal region meets the caudal maxillary region
-Very thin and a little inflammation can have a big affect
How do you determine whether or not you have a fluid line in your x-ray?
Look at the mitchel marker and beads, see where there is an almost soft tissue opacity going straight across
What are the x-rays that should always be taken when investigating the sinuses?
Lateral, oblique, dorsoventral
When is CT used?
For complex disorders
-Tooth root disease
-Sphenopalatine sinus
-Complex trauma
-Use if recurrent disease
-Great for the delicate boney structures in sinus, surgery prep, standing sedation
What is sinus trephination?
Drilling hole into the sinus under standing sedation
-Can use to lavage or investigate, biopsy
-Standing sedation and local analgesia
What are the sites of sinus trephination?
Choncofrontal - frontal, dorsal cohchal, caudal maxillary, sphenopalpatine
-60% distance from midline to medial canthus, 0.5cm caudal to medial canthus
Caudal maxillary site - communicate with choncofrontal through lavage
-2cm rostral and 2cm ventral medial canthus
Rostral Maxillary site - rostral and ventral
-40% from rostral end of facial crest to medial canthus, 1cm ventral from infraorbital foramen and medial canthus
-Need fenestration through maxillary septal bulla to make all sinus compartmentc communicate
What structure is between sinus compartments that if penetrated will make all sinuses connect?
Maxillary septal bulla
What is sinoscopy?
It is cutting a portion of bone away to get into the sinus
-1 inch diameter
- visualization
- for cystand tooth root abscesses, biopsy
What are bone flaps used for?
Treatment after diagnosis using sinuoscopy or if large lesion on diagnostic image
-Allows access to sinus
What are the most common differential for sinonasal diseases?
Primary Sinusitis
Dental Sinusitis
Sinus cyst
Sinus neoplasia
Ethmoid hematoma
trauma
mycosis
cheeck tooth infection
Polyp
What is primary sinusitis?
When you cannot find a cause for the sinusitis
Inflammation of the sinus that can block off normal sinus drainage
-Viral common
-Mucus accumulates and bacteria gorws
-Acute - broad antimicrobials
-Lavage if chronic
What is secondary sinusitis?
second to a primary disease - dental common (08, 09, 10, 11 maxillary cheek teeth)
-Sinus mass obstructs sinus drainage (paranasal sinus cyst, sinus neoplasia, progressive ethmoid hematoma
What is the most common cause of sinusitis?
Dental disease
What is a circular lesion you may find on an oblique radiograph that is fluid filled (yellow fluid), can cause deformation of facial bones and loss of bon) - it can obstruct as well and lead to sinusitis ?
Sinus Cyst
How do we remove a sinus cyst?
Surgically - need to get all of the lining
What looks like a soft issue opacity on radiograph, loss of bone archetecture, facial deformities can be seen?
Sinus Neoplasia
What are common types of neoplasia that may be found in the sinus?
SSC, Adenocarcinoma, fibroma, chondroma, hemagiosarcoma, osteoma
What is the prognosis for sinus neoplasia?
Poor - even with surgical resection and radiation
-Less than 6 months
What disease is common in young horses, can be seen on oblique rads as a gap and periosteal proliferation of the facial structures, can be secondary to trauma?
Suture Periostitis
What is a facial suture of a horse?
Fibrous connective tissue between flat bones of the face
What disease:
-Clinical signs: acute epistaxis, disruption of resp mucosal lining sinus, fresh to brown, secondary mucopurulent nasal discharge, bacteria in lining grow in blood, emphysema,X-ray to see gap due to trauma in older horse:
Sinus Trauma Fractures
What else should you examine if you suspect a fracture of the sinus from trauma?
Evaluate the eye, endoscopy and neurologic exam
-Multiple oblique rads or CT
How do you treat sinus trauma fractures?
Reduce soft tissue swelling - antibiotics and antinflamatories
-surgical repair indented fractures
-can treat conservatively but poor prettiness cause of callus
-Orbital fracture need surgery to prevent harm to globe
What disease:
Clinical signs: intermittent unilateral epistaxis? Abnormal resp noise, on endoscopy has dark red to tan brown encapsulated mass, usually in ethmoid region, can see on rads, ct and sinoscopy
Progressive Ethmoid Hematoma
How can you treat progressive ethmoid hematomas?
Formalin Injection - 1st line, repeat every 3-4 weeks, 5 repeat injections, scab and slough, laser ablation
-Careful can cross cribriform plate and harm brain
Why may ethmoid hematomas recur?
Involvement of sphenopalatine sinus (ct)
