Exam 2: Lecture 12: Tracheal Collapse Flashcards
_____ is a form of tracheal obstruction caused by cartilage flacidity and flattening
tracheal collapse
sometimes erronesouly referrered to as ______ in older literature
congenital tracheal stenosis
T/F: cause of tracheal collapse is generally unknown and probably multifactoral
true
Proposed causes of tracheal collapse are?
- genetric factors
- nutritional factors
- allergens
- neurologic deficiencies
- Small airway disease
- Degeneration of cartilage matrices
Clinical pathology presented below is linked to?
- hyaline cartilage replaced by fibrocartilage and collagen fibers
- cartilages lose rigidity and ability to maintain normal tracheal conformation during respiratory cycle
- may be confined to an isolated segment or may involved the entire trachea and bronchial tree
- typically occurs in a dorsoventral direction (lateral collapse has been reported)
tracheal collapse
Cervical and thoracic inlet collapse during ______ for tracheal collapse
inspiration
Intrathoracic collapses on _____ for tracheal collapse
expiration
What structure is the most susceptible to tracheal collapse
thoracic inlet
collapse reduces the lumen size and interferes with airflow to the ______
lungs
Abnormal respiratory noises, exercise intolerance, gagging, and varying degrees of dyspnea occur with which disease?
tracheal collapse
______ becomes an important tracheobronchial clearning mechanism
coughing
What is the signalment for anmimals with tracheal collapse
typically toy- and minature-breed dogs
- toy poodles
- yorkshire terriers
- pomeranians
- maltese
- chihuahuas
males and females are affected equally
Smaller or larger dogs usually associated with trauma, deformitiy, or intraluminal or extraluminal masses should not be equated with tracheal collapse in toy-breed dogs
larger
What is the classical occuring age range for animals with tracheal collapse
middle aged or older toy breeds
- average 6-8 years
- frequently diagnosed in dogs with respiratory problems between 6 months and 5 years of age
Normal history of animals with tracheal collapse are?
- onset of clinical signs often before 1 year old
- often progress with age and included abnormal
= respiratory noise
= dyspnea
= exercise intolerance
= cyanosis
= syncope
T/F: some dogs with tracheal collapse nerve suffer respiratory distress, others die os asphyxiation, and clinical signs are more severe in obese animals
true
Respiratory noises in animals with tracheal collapse include?
- wheezing
- hacking
- stridorous breathing
some dogs do not make abnormal noises
How would you define the coughing in animals with tracheal collapse
- may be productive or non-productive
- classically a “goose honk” cough
- ofte becomes cyclic and paroxysmal
- gagging after coughing may occur in as many as 50% of cases
Gagging after coughing may occur in _____% of cases with tracheal collapse
50%
Clinical signs of tracheal collapse may be elicited or exacerbated by?
- tracheal infection
- tracheal compression
- exercise
- excitment
- eating
- drinking
- hot / humid weather
- noxious stimuli
These concurrent problems may effect animals with which disease?
- almost 50% of dogs and obese
- laryngeal paresis or paralysis has been reported in 20-30%
tracheal collapse
These concurrent problems may effect animals with which disease?
- systolic heart murmur consistent with mitral valve insufficientency in 1/3
- enlarged left atrium putting pressure on the carina and mainstream bronchi may aggravate upper respiratory sigsn
tracheal collapse
The concurrent problems may affect animals with which disease?
- greater than or equal to 40% of dogs thought to have dental or peridontal disease
= aspiration of oral bacteria into diseased airways is hypothesized to contribute to exacerbation of clinical signs caused by ingreasing airway inflammation or increasing coughing
tracheal collapse
What is the reason for the association with tracheal collapse and hepatomegaly and hepatopathy?
reason is unclear
T/F: Hepatomegaly and Hepatopathy are common in animals with tracheal collapse
true
PE findings of animals with tracheal collapse are?
- flaccid tracheal cartilaes with prominent lateral borders on palpation of the cervical trachea
- paroxysmal coughing on palpation
- abnormal respiratory noises
Auscultation during a PE in animals with tracheal collapse?
- abnormal respiratory noises
- mitral valve disease
- soft end-expiratory snapping together of the tracheal wall
- abnormal heart sounds associated with concurrent cardiac disease
Inspiratory + expiratory lateral radiographs of neck and thorax diagnostics in around ____% of patients with severe tracheal collapse (more than 50% of the lumen)
around 60%
For DI of an animal with tracheal collapse which tracheal cartilages are expected to collapse on inspiration?
cervical
For DI of an animal with tracheal collapse which tracheal cartilages are expected to collapse on expiration?
thoracic
Why are thoracic radiographs beneficial for tracheal collapse?
- often revel cardiomegaly + pulmonary disease
- brochiectasis on 30% of thoracic radiographs
What does this image show?
lateral radiograph of a 2 yr old yorkshire terrier with tracheal collapse (arrow) at the thoracic inlet
What is the purpose for Fluoroscopy?
- facilities evaulation of dynamic movement
- finds many cases missed by survey radiographs
- will miss collapse of the trachea in lateral dimensions
Diagnotic imaging may require multiple imaging modalities as well as?
bronchoscopy
Which technique should be usually be done att he same time as tracheoscopy because laryngeal paralysis or collapse is present in approximately 30% of dogs with tracheal collapse
laryngoscopy
What is the importance of tracheostomy / bronchoscopy?
- confirm and grade the severity of collapse
- evaluate the entire tracheobronchial tree
- collect airway samples for cytology + culture
- confrim location of collapse
Which grade of tracheal collapse is described as?
- complete obstruction
- tracheal lumen is obliterated
grade 4
Which grade of tracheal collapse is described as?
- severe flattening of tracheal cartilages
- 75% loss of luminal diameter
grade 3
Which grade of tracheal collapse is described as?
- relatively normal tracheal cartilage anatomy
- redundant dorsal tracheal membrane decreases lumninal diameter up to 25%
grade 1
Which grade of tracheal collapse is described as?
- Mild to moderate flattening of treacheal cartilages
- 50% loss of luminal diameter
grade 2
Which grade of tracheal collapse is described as?
grade 3
- dorsoventral tracheal collapse
What labatory and ECG findings may be presented in an animal with tracheal collapse
- hematologic + serum biochemistry usually normal or insignificant
- positive trachebronchial cultures greater than 50%
- ECG may revel
= sinus arrythmias
= cor pulmonale (right sided heart failure)
= left ventricular enlargement
Differential diagnosis in animals with symptoms like tracheal collapse are?
- brachycephalic syndrome
- tonsillitis
- laryngeal paralysis
- bronchitis
- tracheobronchitis
- tracheal neoplasia
- allergies
- heart worms
- pulmonary disease
- cardiac disease
- hypoplastic trachea
- tracheal stenosis (congential or acquired)
When is medical management reccomended for animals with tracheal collapse
mild clinical signs and for those with greater than 50% collapse
- results in improvement in clincial signs in most dogs
T/F: weight loss is critical in animals with tracheal collapse
true
Environmental modifications to help with tracheal collapse are?
- harness instead of a collar
- nonsmoking atmosphere
- management of concurrent underlying conditions
Medical therapy in animals with tracheal collapse include?
- antitussives
- antibiotics
- bronchodilators
- +/- anti-inflammatory agents
Severly dyspnic patients may require?
- sedation
- supplemental oxygen
What type of inhalers may be used with spacers and face masks in cooperative dogs to administer aerosolized bronchodilators and corticosteroids
pediatric metered dose inhalers
Reponse to medical therapy in animals with tracheal collapse is uaually ______, and the disease typically progresses
transient
When is surgical treatment for tracheal collapse recommended?
- dogs with moderate to severe clinical signs
- more than 50% reduction of the tracheal lumen
- refactory to medical therapy
Poor surgical canidates include dogs with?
- laryngeal paralysis or collapse
- generalized cardiomegaly
- bronchial collapse
- chronic pulmonary disease
- collapsed mainstem bronchi
What is the goal of surgery in animals with tracheal collapse
support the tracheal cartilages and trachealis muscle while preserving as much of the segmental blood and nerve supply to the trachea as possible
Surgical techniques for tracheal collapse include?
- extraluminal ring prostheses
- endoluminal stenting
Preoperative management of animals with tracheal collapse include?
- observed closely before surgery for signs of progressive dyspnea
- intraoperative prophylatic antiobiotics
- pretreat with anti-inflammatory dose of glucocorticoids in small patients to minimize tracheal swelling
The segmental blood and nerve supply to the trachea runs which directions in relation to the trachea?
travels in the lateral pedicles on each side of the trachea
T/F: minimal mobilization of the trachea is necessary to maintain a good blood supply after surgery
true
Where does the left and right laryngeal nerve located in relation tp the trache
left - lateral pedicle
right - sometimes in the caroitd sheath
How do you position a pt for extraluminal ring prosthesis
- dorsal recumbency
- neck extended and elevated over a pad
- the caudal mandibular area, ventral neck and cranial thoracic should be clipped and preppared for aseptic surgery
What are the 2 surgical treatments for collapsed trachea?
- extraluminal ring prosthesis
- endoluminal stent placement
advanced surgical producedures recommended referral
What does this image show?
Extraluminal ring prosthesis
What surgical technique does the following describe?
- Minimally invasive technique used for intraluminal prostesis placement varies with the type of self-expanding elastic implant selected
Endoluminal stent placement
What surgical technique does the following describe?
- Stents are placed under general anesthesia using tracheoscopy and fluoroscopy
- selection of implant size must be accurate
Endoluminal stent placement
What surgical technique does the following describe?
- implant should remain approx. 10 mm for the larynx and the carnia to prevent excess irritation and granulation
- if the stent is near the thoracic inlet, constant movement at that point often leads to early fracture of the stent
- open-looped or knitted implants are preferred because they promote coverage of the stent with tracheal epithelium
Endoluminal stent placement
What does this image show?
endoluminal stent placement
Post op care and assessment in animals with endoluminal stent placement is?
- continious monitoring during recovery
- acute respirator distress
- nasal insufflation of oxygen
- Anti-inflammatory dose of glucocorticoids may be beneficial in animals with edema and inflammation
- mucolytics and saline nebulization for those with severe inflmmation
- Antibiotics continued for 7 to 10 days if bacterial tracheitis is present
- cage rest for 3-7 days
- tracheoscpoy recommended 1 to 2 months after surgery
- coughing and lack of marked improvement in clinical signs should be expected for several weeks postoperatively
T/F: The quality of life is improved for most patients, but neither surgery nor stents cure the condition
true
Complications of endoluminal stent placement includes?
- death
- coughing brushing
- swelling
- recurrent laryngeal nerve damage results in larngospams/laryngeal paresis / paralysis
- tracheal necrosis
- stent migration
- granuloma formation
- hemorrhage
- emphysema
- pneumomediastinum
- infection
- mucous obstruciton
- tracheal rupture
- squamous metaplasia
- tracheal shorterning
- implant fracture
- implant collapse or deformation
What is the prognosis with tracheal collpase surgery?
more dependent on concurrent respiraton problems, such as layngeal paralysis or collapse and bronchial disease, than on the location or severity of tracheal collapse
Regardless of treatment type, the presence of mainstem bronchi collapse is associated with shorter or longer survival times?
shorter
