Upper airways (E1) Flashcards
What is the purpose of inserting silicon tubes that protrude from the nares when performing nasal surgery?
To maintain the airway/To keep the airways open
What condition is nasal planum resection most commonly associated with?
Neoplasia (SCC)
Accurate apposition of nasal _____ and ____ reduces the risk of post- nasal planum resection stenosis in dogs,
Mucosa
Skin
T/F: The first line treatment for nasal fibrosarcoma is chemo and radiation, if that does not work surgery should be considered.
False, resection is the primary method of treatment since FSA do not respond well to chemo or radiation.
What is the best modality to assess oropharyngeal and nasal pathology, such as polyps?
CT
__________ sutures work well in cats to decrease the size of the wound, allowing the remaining defect from a nasal planum resection to heal by second intention.
Purse-sting
What anatomic structure must you take care to avoid when performing a blind nasal biopsy?
Cribiform plate (no touchies)
Which arteries do you risk damaging when performing nasal surgery?
Dorsal, lateral and major palatine arteries
What are some primary components of brachycephalic airway syndrome
Elongated soft palate (most common)
Stenotic nares (also common)
Shortened, flattened nasal cavity (nasopharyngeal turbinates)
Hypoplastic trachea
What inspiratory noise is associated with an elongated soft palate?
Stertor
T/F: Placement of a stent is the primary treatment for hypoplastic trachea.
False, there is no treatment.
Which drugs should you avoid when performing an upper airway exam, because they affect laryngeal function? What is usually used?
Ketamine
Diazepam
Large doses of pure mu agonists
Use: Propofol +/- Bup or Torb, Doxapram if they get too deep
What surgery is necessary for stage 1 tracheal collapse? Stage 2? Stage 3?
1: Excision of everted laryngeal saccules
2: Above + vocal fold excision and partial arytenoidectomy
3: Permanent tracheostomy
At the beginning of an upper airway examination you notice small pear-shaped masses just in front of the vocal folds. What are these?
Everted laryngeal saccules
What landmarks are used to determine the level of excision when resecting a soft palate?
The caudal border of the soft palate (should slightly cover the tip of the epiglottis on the midline)
Caudoventral border of the tonsillar crypt
Why are wet sponges used around structures that area not meant to be cut by a CO2 laser?
To protect them by absorbing the laser beam
T/F: Nasal stenosis is more common in cats than dogs post-op.
False, dogs.
T/F: Rhinoscopy and nasophyngoscopy should be performed after imaging.
True
Progressively worsening inspiratory dyspnea which is exacerbated by exercise is the most common clinical sign for _____.
BAS
When performing nasal surgery, a ______ approach gives you access to the nasal cavity and sinuses, while a _____ approach gives you access to the choanae.
Dorsal
Ventral (also gives access to ventral nasal cavity)
Which technique is the easiest but also most traumatic for soft palate resection? Broadly, what type of suture and what suturing pattern would you use?
Clamp/crush technique
Fine absorbable monofilament suture (e.g. 4.0-6.0 Monocryl or Biosyn)
Continuous pattern, from edge to midpoint on each side
(Also, remember you (clamp,) cut, and suture one side and then (clamp,) cut, and suture the other side)
T/F: Tracheal collapse and everted laryngeal saccules are secondary or acquired components of brachycephalic airway syndrome.
True
If a laser is not available, what technique for resecting a soft palate is recommended?
Free-hand “cut and sew”
What complications accompany an overshortening the palate in a palatectomy?
Nasal reflux
Aspiration
T/F: An upper airway exam should be performed under deep anesthesia to prevent swallowing.
False
What technique for a palatoplasty would you use if you wish to both shorten and thin the palate?
Folded Flap
What are acute complications following a palatectomy?
Hemorrhage
Inflammation
What do you do if you discover that while performing a palatectomy you undershortened the palate?
Redo the surgery
What diagnostics, aside from an upper airway exam, are warranted when working up a case of BAS?
Thoracic radiographs
Blood work (especially if in distress)
+/-: Lateral cervical rads, abdominal rads/US
What therapies are commonly administered pre-op to soft palate resections and everted saccule excision?
Dexamethasone/ corticosteroids (ALWAYS)
GI protectants and promotility agents
Anti-emetics
Pre-oxygenation
What is considered to be the first step in the pathogenesis of laryngeal collapse?
Eversion of laryngeal saccules
What occurs as laryngeal paralysis progresses from stage 1 to stage 2? (Hint-involves cuneiform processes)
Cuneiform processes rotate medially (which may cause minimal to no abduction of the arytenoids when viewed during laryngoscopy)
What 2 things should you consider when choosing which technique to use to correct stenotic nares?
Severity of collapse
Static vs Dynamic collapse
What analgesic drug is commonly used after a surgery to repair stenotic nares?
Buprenorphine
You have a patient whose laryngeal cartilages are collapsing medially but some glottic lumen remains. What stage of laryngeal collapse are they in? What surgeries are indicated?
Stage 2
Partial arytenoidectomy and vocal fold resection
T/F: A unilateral partial arytenoidectomy is greatly preferred to a bilateral to reduce the risk of creating laryngeal incompetence leading to aspiration pneumonia.
True
Why is arytenoid lateralization surgery not helpful In the treatment of laryngeal collapse?
Because it may make the collapse worse if the cartilages do not have normal rigidity
What approach do you take when performing a partial arytenoidectomy and vocal fold resection? What is the most common complication and how is it prevented?
Oral
Post-op stricture (“webbing”)
Keep the ventral commissure of the vocal fold intact and do not cut to the dorsal or ventral extents of the corniculate processes and vocal folds.
T/F: When performing a permanent tracheostomy, the stoma should be made smaller than you would think necessary because the hole will stretch out as it heals.
False, must be made LARGER because a 40-50% reduction of the stoma is typical during healing
Your patient develops fever post-operatively after laryngeal surgery. What complication do you fear has occurred?
Aspiration pneumonia
What congenital condition for which clinical signs usually begin around 4-6 months of age is frequently reported in Bouvier des Flanders, Siberian huskies, bull terriers, Leonbergers, Dalmatians and Rottweilers? Progressive deterioration can occur at a rapid rate, especially in Rottweilers.
Laryngeal paralysis
At which stage of laryngeal collapse may the corniculate and cuneiform processes overlap? What surgery is indicated?
Stage 3 Permanent tracheostomy
Which muscle is responsible for laryngeal abduction?
Crycoarytenoidesous dorsalis
What acquired condition occurring most frequently in older, medium to giant breeds of dog such as Labrador retrievers, has an insidious onset with intermittent episodes of severe respiratory distress?
Acquired laryngeal paralysis
What are the openings between the nasal cavity and the nasopharynx called?
Choanae
Laryngeal paralysis results in an inability to properly abduct the laryngeal cartilages during _______.
Inspiration
Why is it important to do a thorough neuro exam, especially in young patients, before undertaking surgical correction of laryngeal paralysis?
Laryngeal paralysis might be the earliest sign of generalized neuromuscular disorders
What 3 methods can you use to stimulate deeper inspiration while evaluating the larynx?
Tracheal palpation
Laryngeal stimulation
Doxapram administration (least likely to cause coughing, so preferred)
What type of laryngeal paralysis is most common in small animal patients?
Idiopathic acquired bilateral
What is the purpose of arytenoid lateralization for treatment of laryngeal paralysis? What structures are sutured together in this procedure? Is this done uni- or bilaterally?
To open the rima glottidis enough (usually 2x size of resting) to relieve the airway obstruction but not so wide as to make the larynx incompetent during swallowing
Suture (2 interrupted non-absorbable sutures) the muscular process of the ARYTENOID cartilage in abduction to the CRICOID cartilage UNILATERALLY
What cases of tracheal trauma would necessitate surgical intervention?
Severe, visible rupture/damage caused by ETT
If dyspnea persists or worsens with medical management
If pnemothorax persists more than 2-3 days
What is the preferred technique for tracheal anastomosis? Why?
Split-cartilage technique
Easier to perform
Results in more precise anatomic alignment with less luminal stenosis (Best on dogs >20lbs)
Name some post-op complications that may occur after tracheal resection and anastomosis
Hemorrhage
Voice change
Fistula formation
Cartilage malacia (not common)
Excessive tension or neck movement can cause dehiscence (can cause SQ emphysema, acute respiratory distress, hemoptysis, SQ swelling)
Excessive tension + healing by second intention -> TRACHEAL STENOSIS
Traumatizing recurrent laryngeal nerves -> laryngospams, laryngeal paresis/paralysis
What are the indications for permanent tracheostomy in the dog? What tissues are sutured in this “ostomy”? How is tension on this suture line reduced? What other procedure may be required in association with a permanent tracheostomy?
Moderate to severe respiratory distress caused by a UR obstruction - laryngeal paralysis, laryngeal collapse, neoplasia
Skin is apposed to tracheal mucosa
Reduce tension using tension-relieving sutures
Placement on external rings adjacent to tracheostomy site might be needed if tracheal cartilage is soft
T/F: Prognosis for dogs in generally better than cats post-permanent tracheostomy.
True
What are the two primary surgical approaches to the thoracic cavity? Describe the advantages and disadvantages of each.
Lateral/Intercostal thoracotomy: used for directed approach to a specific structure in the thorax; less painful approach but time consuming and can be associated with rib fractures in small animals
Median sternotomy: used for bilateral thoracic exploration, cranial mediastinal masses and to access the cranial thoracic trachea; more painful, and more invasive
What approach would you use for a pneumonectomy?
Lateral intercostal
Which nerves run along the dorsolateral aspect of the trachea?
Recurrent laryngeal nerves
What kind of approach would you take for a ventriculocordectomy if you wish the dog the be completely aphonic?
Ventral
T/F: To alleviate SQ edema, the most reliable method is to aspirate the air bubble with a needle and decompress the area.
False, usually not a single bubble but a collection of small ones so this usually doesn’t work
T/F: Most tracheal tears, even if minor, require immediate surgical intervention.
False, most minor tears resolve with medical management including cage rest, O2 supplementation, neck wraps and sedatives
What modality is best for diagnosing tracheal stenosis?
Tracheoscopy
Aside from tension, what causes post-op stricture after preforming a tracheal resection/anastomosis?
Inflammation
Poor apposition of mucosa and skin
What surgical approach would you use to explore the chest for a foreign body?
Median sternotomy
What is the term for removal of all lobes of one lung?
Pneumonectomy
T/F: Using staples instead of sutures in a lobectomy is preferred when the option exists and the patient size allows, because it decreases anesthesia and surgery time.
True
T/F: Untwisting a lung torsion is the first step in any surgical repair.
False, NEVER untwist (otherwise risk reperfusion injury)
On which side of the chest are partial lung lobe torsions possible?
Left
What techniques can be used to perform a complete lobectomy? What methods can be used to perform a partial lobectomy?
Complete: Lateral thoracotomy or Thoracoscopy
Partial: (Lateral 4th or 5th) Intercostal thoracotomy or Median sternotomy
What are 2 possible causes of lung torsion? What is the typical signalment of a dog with lung lobe torsion? What lobes tend to be affected?
Pleural effusion
Partial collapse of lung lobe
Sig: Large, deep chested dogs (Afghan’s) or Pugs
Large dogs: middle or left cranial lobe
Pugs: left cranial lobe
A ___ (bulla/bleb)is located peripherally in the lung and easily seen. A ___(bulla/bleb) is deep in the lung, sometimes requiring attentive palpation to locate.
Bleb
Bulla
What breed is at increased risk for primary spontaneous pneumothorax?
Siberian huskies
What are the 2 most common types of primary pulmonary neoplasia? Which has a better prognosis?
Adenocarcinoma (better prognosis)
Squamous cell carinoma
What injury is associated with hyperextension of the neck, such as high rise syndrome?
Tracheal transection/avulsion (usually at the level of the hilus)
Why do animals with fractured ribs become hypoxic? What can you do to alleviate this condition?
Rib fractures may interfere with ventilation if the animal splints the thorax in an attempt to reduce pain by reducing motion of the fragments.
Splinting can improve comfort
What is the recommended treatment for a simple flail chest?
External splinting (thermoplastic material)
Rapid deflation of lungs with open glottis produces a large pleuroperitoneal pressure gradient, resulting in a/an ____________.
Diaphragmatic hernia
T/F: Objects penetrating the chest wall should not be removed outside of the OR and after taking rads.
True
Peritoneopericardial diaphragmatic hernias are always congenital in dogs and cats. Are these hernias inherited? What concomitant abnormalities may be found?
They might be, could be caused as a result of a teratogen, genetic defect, or prenatal injury.
Cardiac abnormalities and sternal deformities
Which organ, if it hernias into the chest makes a hernia repair an emergency?
Stomach
What approach do you ALWAYS take when preforming a diaphragmatic herniorrhaphy?
Ventral midline abdominal approach
What complication is most common associated with repairing a chronic diaphragmatic hernia?
Re-expansion pulmonary edema (fatal, no tx)
What is the congenital deformity where there is inward concavity of the sternum? How is it treated?
Pectus Excavatum
External splint
What is the most commonly displaced organ with a diaphragmatic hernia?
Liver
What is the landmark for a intercostal thoracotomy to access to cranial thoracic trachea? What if you needed to access the tracheal bifurcation or wanted to repair an avulsion?
Right 3rd ICS
Right 4th ICS
