Principles of endoscopy Flashcards
Give examples of diagnostic endoscopy
airway fluid sampling/bronchoalveolar lavage
tissue biopsies (GI tract, nasal and bladder mucosa)
Give examples of therapeutic endoscopy
removal of a foreign body from oesophagus, airway or stomach
management of an oesophageal stricture
placement of a gastric feeding tube (PEG)
Injection of collagen to improve urinary continence
What equipment is needed for flexible endoscopy?
Flexible endoscope
Air insufflation and water irrigation system
Suction to allow aspiration of air and body fluids
Operating channel for acquiring samples (Biopsies/BALs)
Video monitor screen +/- image capture system
Instruments (appropriately sized):
- biopsy forceps
- foreign body retrieval forceps and baskets
- cytology brushes
- broncho-alveolar lavage catheters
Leak testing equipment
Cleaning equipment
What small animal GI signs would indicate the need for GI endoscopy?
Suspicion of anatomic oesophageal disease where megaoesophagus has already been ruled out with radiography
Vomiting due to a gastric foreign body
Suspected severe gastric ulceration
Chronic GI Signs:
- vomiting/haematemesis/melaena
- chronic diarrhoea
- weight loss
What should you remember to do before/during GI endoscopy?
Rule out other causes that would not require endoscopy to reach a diagnosis before you scope (e.g. pancreatitis, Addisons, CKD)
Even when a very obvious gastric lesion is found, always scope the duodenum/SI as well as the stomach
Always collect multiple biopsies from multiple sites - abnormal GI tract might look grossly normal
What respiratory signs would indicate the need for bronchoscopy in small animals?
Cough where foreign body is suspected, or airway fluid sampling might be helpful (cytology/culture/PCRs)
Dyspnoea where infection is suspected
What should you do prior to performing bronchoscopy?
Rule out pleural space disease (Ultrasound).
Always perform diagnostic imaging first (radiography or CT)
What urinary signs in dogs indicate the need for urinary endoscopy?
Lower urinary tract signs eg dysuria, haematuria, incontinence
What should you do prior to performing urinary endoscopy in a dog?
Always perform urinalysis and diagnostic imaging first (radiography +/- ultrasound +/- contrast studies)
Consider whether the anatomy is best suited to rigid scope (females) or flexible scope (male)
When might we use endoscopy in horses?
Suspected upper airway/laryngeal obstruction
Examining the guttural pouch
Investigation of abnormal respiratory noise
Suspected lung disease
Gastric ulceration
Urinary tract disease
Describe the need for GA in endoscopy
Needed in small animals
Not needed in horses
What patient prep is needed prior to endoscopy?
GI endoscopy - starvation as GI tract needs to be empty
What are the 2 types of flexible endoscopy?
Fibreoptic endoscopes
Video endoscopes
What are the disadvantages of a fibreoptic endoscope?
pixelated images with smaller diameters and/or
damage to optic fibres reduces image quality
older technology
What are the advantages and disadvantages of video endoscopes?
superior image quality and reduced repair costs
more expensive to buy
What are the main components of a flexible endoscope and their functions?
Insertion tube - goes into patient (fragile)
Handpiece - control of scope tip, air/water suction buttons, instrument/biopsy channel
Light guide connector
What is flexible endoscopy used for?
GI endoscopy (diagnostic)
Bronchoscopy
Nasopharynx
Urethroscopy/cystoscopy in male dogs
What are the limitations of flexible endoscopy?
Even long scopes may not be long enough
Small diameter scopes only allow small biopsy instruments
Biopsy channel varies in diameter which lead to challenges over interpretation and how valuable these are:
- Ideally >2mm to be useful for diagnosis.
- smaller endoscopes may only have 1mm working channels.
What are the advantages and disadvantages of rigid endoscopy?
Advantages: cheaper, less prone to damage, superior image, allows larger instruments to be used
Disadvantages: restricted access to some anatomical sites, additional equipment required
What additional equipment is needed for rigid endoscopy?
Sheaths: protect the scope, allow fluids to pass through side ports, direct biopsies
What is rigid endoscopy used for?
Rhinoscopy
+/- flexible endoscopy for the caudal nasopharynx
Arthroscopy
Cystoscopy in bitches
Otoscopy
Laparoscopy
(bronchoscopy)
What are the limitations of rigid endoscopy?
Risk of causing damage and mucosal bleeding which restricts ability to see lesions e.g. rhinoscopy/urethroscopy
Unable to manoeuvre around anatomical bends
No real ability to insufflate with air effectively
