Tracheal Surgery Flashcards
1
Q
2 functions of the annular ligaments of the trachea:
A
Shape
length accomodation
2
Q
Is the trachealis muscle on the dorsal or ventral aspect?
A
Dorsal connection
3
Q
What important structure lives on the lateral aspect of the wall of the trachea?
A
Recurrent Laryngeal nerve – laryngeal dysfunction if damage on the lateral side of trachea
4
Q
What 2 muscles are split when doing the cervical ventral midline approach?
A
Sternohyoideus m.
Sternothyroideus m.
5
Q
4 structures in the carotid sheath:
A
Carotid
Vagosympathetic trunk
Vagus n.
Internal Jugular vein
6
Q
For the cranial cervical trachea, what surgical approach is used:
A
Cervical Ventral Midline
7
Q
Approach the trachea from the ____ side :
A
Right
8
Q
For the caudal cervical & cranial thoracic trachea, what surgical approach is used:
A
Median Sternotomy
9
Q
Name the ICS for Intercostal thoracostomy:
A
Right 3rd ICS ==> Cranial thoracic trachea
Right 4th ICS ==> Tracheal bifurcation
10
Q
What process/ surgical dz is tracheal collapse:
A
Degenerative change – progressive, irreversible degeneration of lower airway (Laxity of the trachealis muscle = weakness of tracheal rings)
11
Q
Factors cause increased weakness/ pliability in tracheal collapse:
A
Decreased water retention secondary to loss of glycoprotein and GAG.
Decreased Calcium and chondroitin.
12
Q
Name 3 things associated with the progressive cough seen in squamous metaplasia:
A
- Squamous Metaplasia
- Reduction of ciliated cells
- Increased viscosity to secretions
13
Q
Cor pulmonale (aka Right heart failure) is associated with tracheal collapse. Name the 2 factors associated with this:
A
- Pulmonary Hypertension
2. RV enlargement
14
Q
Most common secondary factor in tracheal collapse:
A
OBESITY – fat deposits in the thoracic cavity causes inability for the lungs to expand creating resp probz.
Wt loss = minimize CS
15
Q
Name the 4 secondary factors of tracheal collapse:
A
- Obesity
- Enviromental allergens
- Respiratory irritants - Cig smoke, aerosol sprays, fireplaces
- Kennel cough
– of 100 cases of tracheal collapse, 55% had >1 coexisting disease.
16
Q
Is tracheal collapse common in small or large breed dogs?
A
Small breed or toy breed dogs
– Yorkie, Poms, mini/toy poodles, Chihuahuas, and pugs
17
Q
What age is most commonly effected for tracheal collapse:
A
Middle Age dogs
- signs at an earlier age consistent with more severe dz.
- no evidence of sex predilection for tracheal collapse.
18
Q
“GOOSE HONKING” cough is a characteristic sign of:
A
Tracheal collapse
–progressive
19
Q
Clinical signs of tracheal collapse are:
A
- Goose honk cough
- wax and waning dyspnea
- exercise intolerance
- cyanosis
- syncope
20
Q
Differentials for tracheal collapse:
A
- Heart dz / Cardiomegaly
- Kennel cough
- Bronchitis
- Pneumonia
- other lower airway dz (neoplasia/ infectious/inflammatory/ FB)
21
Q
Important diagnostic for tracheal collapse:
A
IMAGING – shows severity & location
others diagnostics are based on: Signalment / history/ CS / PE
22
Q
T/F: Radiographs have variable sensitivity & low specificity for tracheal collapse but can be useful to determine if collapse if cervical or thoracic.
A
True
– must image entire trachea
23
Q
If it is a cervical collapse, the collapse happens during inspiration or expiration?
A
Inspiration
- Cervical = Inspiration [CI]
- Thoracic = Expiration [TE]
24
Q
if it is a thoracic collapse, the collapse happens during inspiration or expiration?
A
Expiration
- Cervical = Inspiration [CI]
- Thoracic = Expiration [TE]
25
What is the term that refers to 'Real time radiographic imaging' that allows visualization of the entire respiratory cycle:
Fluoroscopy
Disadvantage: This method has had false positives reported & hard to interpret.
Advantage: No sedation or anesthesia is typically required (may require Anxiolytic for dyspnea)
26
Gold Standard diagnostic for tracheal collapse:
TRACHEOSCOPY
- - allows direct visualization of collapse (Grading of severity)
- - allows visualization of tracheal mucosa & dorsal tracheal membrane
27
Tracheoscopy allows visualization of:
- - collapse
- - tracheal mucosa
- - dorsal tracheal membrane
28
Advantage of Tracheoscopy:
Can obtain samples for cytology & bacterial culture/ sensitivity.
29
Disadvantage of Tracheoscopy:
Requires anesthesia which may incite DYSPNEIC EPISODE
30
If the lumen reduction is 25%, what grade is the tracheal collapse:
Grade 1
31
If the lumen reduction is 75%, what grade is the tracheal collapse:
Grade 3
32
If the lumen reduction is 50%, what grade is the tracheal collapse:
Grade 2
33
if there is almost NO lumen, what grade is the tracheal collapse:
Grade 4 (IV)
34
When is surgery indicated in tracheal collapse:
ONLY WHEN MEDICAL MANAGEMENT FAILS IS SURGICAL TREATMENT CONSIDERED!!!!
-- wt loss drugs (medical management)
35
What is the only time you would use external prosthetic tracheal rings for tracheal collapse:
CERVICAL TRACHEA collapse only!
36
What surgical approach is used when placing external prosthetic tracheal rings for tracheal collapse:
VENTRAL midline cervical approach
-- Pope said this twice.
37
What do you secure the external tracheal rings to:
secure to cartilaginous rings of normal trachea
-- must start & end ring placement in area of normal trachea
38
T/F: External Prosthetic tracheal rings have a good outcome with IMMEDIATE improvement in clinical signs
True
39
What type of syringe is cut & used as a external prosthetic tracheal ring:
Polypropylene syringe cut into barrels with tiny holes in them to secure to cartilaginous rings of the normal trachea.
---Non-absorbable Monofilament Polypropylene suture as well as the polypropylene syringe ( less inflammation than nylon).
40
3 complications of using External Prosthetic tracheal rings:
1. Laryngeal paralysis
2. Tracheal Necrosis
3. Pneumothorax
41
What complication of an External Prosthetic Tracheal ring can become life threatening:
Tracheal necrosis
- - secondary to damage to trachea's segmental blood supply (disruption of blood supply)
- -- life threatening (Cough, SQ emphysema)
42
Pneumothorax is a complication of External prosthetic tracheal rings. How does the pneumothorax occur:
The holes placed could create pneumothorax or pneumediastinum.
- - diffusion of air through mediastinum during sx
- - accidental penetration of thoracic cavity near caudal cervical trachea
43
Which complication of external prosthetic tracheal rings have been reported in 11-30% of surgical cases:
Laryngeal Paralysis
-- damage during sx to the laryngeal nerve vs. continued trauma from implants
44
What structure provides circumferential support, for tracheal collapse, WITHOUT affecting surrounding vessels or nerve:
Intraluminal Stent
45
How is a intraluminal stent placed:
Fluroscopically or endoscopically
- - self expanding nitinol stent
- -constrained on a delivery system
- - sizing (diameter & length) based on imaging, Esophageal measurement probe
46
Complication of intraluminal stents:
Once the stent opens you cannot get it back. **make sure you check the position**
47
What can be combined with external rings when the tracheal collapse extends up to the crycocartilage:
intraluminal stent can be combined with external rings
48
Name the Intraluminal stent advantages:
Intraluminal Advantages:
- - minimally invasive
- - shortened anesthesia time
- - ****Can be used in the cervical AND thoracic trachea**
- - immediate improvement in clinical signs
49
Name the intraluminal stent disadvantages:
Intraluminal Disadvantages:
- - requires fluoroscopy or endoscopy
- - $$$
- - shorter life span than tracheal rings
- - moderate to high complication rate
50
What can be used to fix tracheal collapse in the cervical AND thoracic trachea:
Intraluminal stent
51
Name 6 complications of stenting:
1. Stent fracture
2. Stent migration
3. Tracheitis
4. Collapse beyond stented region
5. Tracheal obstruction secondary to granulation tissue formation
6. Tracheal rupture
52
T/F: If stent fracture occurs, it can be life threatening if pieces migrate
True
Other complications:
- - Stent migration: secondary to incorrect sizing
- - Tracheitis: documented in 60% of patients
- - collapse beyond stented region: Mainstem bronchi collapse
- - tracheal obstruction secondary to granulation tissue formation: can respond to tx with corticosteroids and colchine.
- - tracheal rupture
53
What drugs are used to treat tracheal obstruction secondary to granulation tissue formation after a stent has been placed:
Corticosteroids & Colchicine
-- Colchicine: prevents intercross linking so it doesn't mature so it can stay flexible
54
60% of patients with complications from a intraluminal stent have:
Tracheitis
55
What is the treatment for collapse of the mainstem bronchi or lower:
NO current treatment for collapse of mainstem bronchi or lower
56
T/F: Surgery is always desired for tracheal collapse.
FALSE--
- -surgery should be avoided if possible = Salvage procedures
- - progression of disease can happen in the face of surgery
57
Causes of internal tracheal trauma:
1. Rupture or necrosis secondary to ET tube (common in cats & dental procedures)
2. FB
58
Causes of external tracheal trauma:
Blunt or penetrating injuries:
1. Bite wounds
2. Lacerations (Puncture/ Avulsions/ Transection vs. loss of tissue )
Tx conservatively = Puncture
Tx surgically = avulsions & transection
59
Main clinical signs associated with tracheal trauma:
SQ emphysema -- "Snap, crackle, and pop"
other signs of tracheal trauma:
- - anorexia
- - lethargy
- - stridor coughing
- - Dyspnea
Progression of pathology in severe cases of tracheal trauma
- - mediastinal Emphysema
- - pneumothorax
60
What 2 clinical signs are associated with severe tracheal trauma:
1. Mediastinal emphysema
2. Pneumothorax
Mediastinum is not very thick so if it ruptures it can lead to pneumothorax.
61
Why would we put in a temporary tracheostomy:
Temporary Tracheostomy:
-- reduces SQ emphysema by bypassing the upper airway( where most resistance is occurring) so they do not have to work so hard to breathe.
62
T/F: Minor rupture of the trachea can be treated with medical management.
True:
63
What is the medical management for a minor tear or minor rupture in the trachea:
Minor Tracheal tear/ rupture tx:
- - cage rest
- - oxygen supplementation
- - sedatives
- -thoracocentesis or thoracostomy tube for pneumothorax
- - consider temporary tracheostomy
64
T/F: If dyspnea persists or worsens, in a minor tracheal tear/rupture, then surgical repair is indicated
True
- - primary closure of tear
- - simple continuous pattern
- - fine, absorbable suture
65
What must be monitored long term in tracheal minor tears/ruptures:
Monitor for scarring & tracheal narrowing long term for minor tracheal tears/ruptures
66
In severe tracheal tears/ruptures, surgical intervention is indicated when:
- - dyspnea persists or worsens with medical management
- - if pneumothorax persists > 2-3 days
- - severe tracheal damage is visible
67
What 2 surgical options are for severe tracheal tear/ruptures:
Surgical options for severe tracheal tear/rupture:
1. primary closure of tear
2. tracheal resection & anastomosis
68
Common place for severe tracheal tear:
Near the base of the heart
69
Tracheal repair ( Resection & Anastomosis) for big dogs:
1. Incise edges
2. Split 2 big rings & bring them together (Anastomosis) -- reduces risk of stenosis post. [ not done on small dogs = small rings ]
3. Place tension relieving suture -- reduces tension on primary suture line
> 4-5 rings = Tension
70
Tracheal repair (Resection & Anastomosis) complications:
Tracheal repair complications:
- - SQ emphysema
- - Pneumomediastinum & pneumothorax
- - infection
- - STRICTURE ********
complications occur if tension or poor healing (stricture requires surgery)
71
What nerve should be avoided in a permanent tracheostomy:
-- Recurrent laryngeal nerve
72
Name the salvage procedure for treatment of untreatable upper airway obstruction.
Permanent Tracheostomy
73
Permanent Tracheostomy complications:
1. infection
2. bleeding
3. stenosis
4. FB
5. increase risk of pneumonia
6. drowning
74
T/F: After a permanent tracheostomy, it is normal to have excessive secretions for weeks post op until the squamous metaplasia of mucosa is complete.
True
75
In a permanent tracheostomy, how much will the stoma decrease (%)?
40-50%
Must oversize stoma at time of surgery.
The stoma will decrease in size by 40-50%
76
What procedure creates permanent opening at the level of proximal cervical trauma:
Permanent Tracheostomy
Steps:
1. ventrally access the trachea
2. elevate trachea up by dissecting underneath ( caution: recurrent laryngeal n.) and placing metzenbaun scissors underneath
3. Suture the hyoid muscles underneath trachea to keep trachea elevated next to surface
4. create hole 40-50% more than what you want - take ring off & leaving mucosa
5. suture mucosa of trachea to skin -- skin apposition is VERY important to prevent scarring.
77
Most important component in success of a permanent tracheostomy
Accurate apposition of mucosa to skin because it reduces scarring & inflammation
78
T/F: Careful at home monitoring is required for permanent tracheostomy
True -- LOTS of work
- - clip hair around stoma
- - no swimming or water submersion
- - protect stoma from FB ( plant material, debri)
- -must use harness
- - avoid airway irritants
79
Which species has the best prognosis for permanent tracheostomy:
Dogs
Dog prognosis -- Good for indoor dogs if underlying disease is benign process. Owners must be diligent with care & may require symptomatic tx for tracheitis.
Cat prognosis -- guarded to POOR.
- - mucus plugs very common leading to acute death
- - median survival times reported to be 20.5 and 42 days.
- - soft tracheal cartilage may predispose trachea to collapse ( consider placement of external rings adjacent to tracheostomy)
