Kapitel 102 - Trachea and bronchi

Question 1

What marks the boarder between the upper and lower respiratory tract?

Answer 1

The cricotracheal junction

Question 2

What vessels supply the trachea?

Answer 2

Cranial and caudal thyroid arteries

Question 3

What is the main innervation of the tracheal mucosa and the trachealis muscle?

Answer 3

Right vagus and recurrent laryngeal nerve

Question 4

What diagnostic tool is required for diagnosis of bronchomalacia?

Answer 4

Tracheobronchoscopy

Question 5

For a bronchial lavage to be considered diagnostic, how much if the infusate instilled must be retrieved?

Answer 5

33%

Question 6

What are the indications for a temporary tracheostomy?

Answer 6

for any condition resulting in upper airway obstruction, including:
i. brachycephalic airway syndrome
ii. laryngeal paralysis
iii. cervical trauma
iv. laryngeal foreign bodies
v. neoplasia
vi. anaphylaxis.

Question 7

What is the recommended tracheostomy tube size?

Answer 7

the outer diameter of the tracheostomy tube should not exceed 75% of tracheal diameter

Question 8

how often should a tracheostomy tube be replaced?

Answer 8

a. tubes should be replaced twice daily; exchange can be required as frequently as every 4 to 6 hours after initial placement because of excess airway secretions.

b. single-lumen tubes must be removed and replaced every time cleaning is necessary, double-lumen tubes have a removable cannula that can simply be exchanged.

Question 9

Airway suctioning is another way to keep the tube clean. For how long should suction be? And what other possible effects if this should be considered?

Answer 9

a. Not more then 10-12 sec. More can lead to severe atelectasis and hypoxia

b. Can also cause a vagal response resulting in gagging, retching or bradycardia. ECG is recommended during the suction procedure.

Question 10

What is the most common long term complication after temporary tracheostomy?

Answer 10

a. Stomal stenosis
i. (two sites have been identified: at the stoma site itself and at the level of the cuff or tube tip)

Question 11

What is the most common indication for a permanent tracheotomy?

Answer 11

laryngeal masses in cats and laryngeal paralysis or collapse in dogs

Question 12

What has been reported as the most common complication of a permanent tracheostomy?

Answer 12

Aspiration pneumonia

Question 13

List three tension-relieved techniques that can be used for tracheal anastomosis

Answer 13

a. Tension-relieving sutures placed several rings proximal and distal to the anastomosis
b. fixed ventroflexion of the neck
c. release of the annular ligaments with preservation of mucosa

Question 14

name two tracheal anastomotic techniques

Answer 14

a. The “split cartilage” technique - involves placing the suture around divided tracheal rings
b. The “annular ligament cartilage” - involves placement of the suture around adjacent tracheal rings through the annular ligament

Question 15

What are the surgical approaches to the trachea?

Answer 15

a. Cervical trachea
* Ventral midline approach
b. Thoracic inlet
* Ventral midline combines with a proximal sternotomy
c. Intrathoracic trachea
* Right sided 3rd-5th intercostal thoracotomy
(azygos vein is identified, ligated and transected for maximal exposure)

Question 16

When does patients with tracheal avulsion usually present?

Answer 16

2-3 w after the injury, presenting with airway obstruction.

Question 17

Have can you histologically differentiate an congenital vs an aquired esophagotracheal fistula?

Answer 17

Congenital fistulae are lined with squamous epithelium rather than granulation tissue because they occur from lack of normal separation during embryogenesis and not from trauma

Question 18

Which diagnostic tool provides the most significant diagnostic information for tracheal collapse?

Answer 18

Tracheoscopy

Question 19

1Nme the tracheal collapse grading system

Answer 19

a. Grade 1: 25% collapse
b. Grade 2: 50%
c. Grade 3: 75%
d. Grade 4: 100%

Question 20

List the different surgical techniques for treatment of tracheal collapse

Answer 20

a. Extraluminal Prosthetic Tracheal Rings
b. Extraluminal Spiral Prosthesis
c. Intraluminal Stents

Question 21

What are the advantages with intra luminal stents?

Answer 21

a. shortened anesthetic time
b. immediate improvement in clinical signs related to tracheal collapse
c. the ability to place the stent within the cervical or thoracic regions or entire trachea in a noninvasive manner.

Question 22

What is the appropriate size of tracheal stent?

Answer 22

a. The stent should be 10-20% wider than the widest part of the trachea, measured on a positive pressure radiograph.

b. The minimum length should span the area of collapse when fully expanded, however preferably it spans the whole area of the traches rather than only the collapsed area.

Question 23

Where is the ideal location of stent placement?

Answer 23

1 cm caudal to the cricoid cartilage and 1 cm cranial to the carina
i. (Stent placement can be achieved with fluoroscopic guidance or direct visualization)

Question 24

List possible complications of tracheal stenting

Answer 24

a. stent fracture
b. stent migration
c. tracheitis
d. collapse beyond the stented region
e. obstruction of the stent lumen with granulation tissue
f. tracheal rupture
g. uncommon complications after stent placement include rectal prolapse and perineal hernia, presumably from refractory paroxysmal cough

Question 25

25. what are your treatment options is case of stent fracture?

Answer 25

a. Fist aggressive medical management. If the dog remains severely symptomatic:
i. a new stent can be deployed within the lumen of the fractured stent
ii. extraluminal rings can be placed around the fractured area
iii. or the stent can be removed via tracheotomy or resection and anastomosis

Question 26

which lobe is most commonly affected by congenital lobar emphysema?

Answer 26

a. Right middle lobe
(but multiple lodes can be affected in the same individual)

Question 27

What radiographic imagine is shown? What condition it this associated with?

Answer 27

a. Situs invertus - the thoracic and abdominal viscera in a mirror image to their normal orientation
b. Ciliary Dyskinesia