Principles of endoscopy Flashcards
What is endoscopy?
Minimally invasive, non-surgical technique that allows direct visualisation of internal body surfaces & sampling from specific regions
What is therapeutic endoscopy & examples?
Used for treatment - allows delivery of a particular therapy
Examples:
- removal of FB from oesophagus, airway or stomach
- management of oesophageal stricture
- placement of gastric feeding tube (PEG)
- Injection of collagen to improve urinary continence
What equipment is required for flexible endoscopy?
Flexible scopes
Light source (xenon, metal halide, LED)
Air insufflation & water irrigation system
Suction for aspiration of air & fluids
Operating channel (for sample collection)
Video monitor & image capture system
What additional instruments may be needed during endoscopy?
Biopsy forceps
FB retrieval forceps/baskets
Cytology brushes
Bronchoalveolar lavage (BAL) catheters
Cleaning & leak testing equipment
When might we use endoscopy in small animals with GI signs?
Suspicion of anatomic oesophageal disease (where megaoesophagus already ruled out with radiography)
Vomiting due to gastric FB
Suspected severe gastric ulceration
Chronic GI signs (e.g. chronic vomiting/diarrhoea, weight loss)
What are some important tips for small animal GI endoscopy?
Rule out conditions that don’t require endoscopy first (e.g. pancreatitis, Addison’s, CKD)
Endoscopy only assesses surface; can’t evaluate function
Always scope duodenum & stomach, even if primary lesion is gastric
Collect multiple biopsies from different locations
When might we use endoscopy (bronchoscopy) in small animals with respiratory signs?
Cough where FB is suspected or airway fluid sampling might be helpful
Dyspnoea where infection is suspected
What are important considerations for bronchoscopy?
Rule out pleural space disease first (with ultrasound)
Always perform radiographs or CT before bronchoscopy
Consider patient size—small airways in cats & small dogs increase risk
“First, do no harm”—balance risks vs. benefits
When is cystoscopy/urethroscopy used in dogs?
Lower urinary tract disease (e.g. dysuria, haematuria, incontinence)
What are important considerations for cystoscopy?
Perform urinalysis & imaging first (radiography, ultrasound, contrast studies)
Rigid scopes are better for females; flexible scopes are better for males
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
What preparation is required for GI endoscopy?
The GI tract must be empty!
Is general anaesthesia needed for endoscopy?
Small animals: Usually yes
Horses: Usually no, as dynamic studies are common
What should you do if everything looks normal on endoscopy?
Always collect multiple biopsies—grossly normal tissue may still have pathology
What are some common complications of endoscopy and how can they be prevented?
Aspiration (prevent with cuffed ET tube)
Scope damage (use mouth gag)
GI perforation (never force scope, always use lubrication)
What is the main difference between rigid and flexible endoscopy?
Rigid endoscopy: Straight, non-bendable, used for direct visualisation
Flexible endoscopy: Long, bendable tip controlled by hand piece, used for deeper access
What are the 2 types of flexible endoscopes?
Fibreoptic endoscopes – Older technology, pixelated image, more robust
Video endoscopes – Better image quality, lower repair costs, more expensive
What are the main components of a flexible endoscope?
Insertion tube (fragile)
- goes into patient
Hand piece (control section)
- Knobs control tip of endoscope
- Air/water & suction buttons
- Instrument/biopsy channel with rubber cap to prevent air escaping
Light guide connector (umbilical or universal cord)
When do we use flexible endoscopy?
GI endoscopy (stomach, duodenum)
Bronchoscopy (airway examination)
Nasopharyngeal exam (e.g., foreign body removal)
Urethroscopy/cystoscopy in male dogs
What are the limitations of flexible endoscopy?
Even long scopes might not be long enough
Small diameter scopes only allow small biopsy instruments
Narrow biopsy channels may limit sample quality
What are the advantages of rigid endoscopy?
Cheaper & more durable than flexible scopes
Better image quality than most flexible endoscopes
Larger biopsy instruments can be used
When do we use rigid endoscopy?
Rhinoscopy (nasal exam)
Arthroscopy (joint exam)
Cystoscopy in female dogs
Otoscopy (ear exam)
Laparoscopy (abdominal cavity exam)
What are the limitations of rigid endoscopy?
Less maneuverability in curved anatomy
Higher risk of mucosal damage & bleeding (e.g. in rhinoscopy)
Cannot insufflate air effectively
What imaging methods should be performed before endoscopy?
Radiographs → Assess general distribution of pathology (e.g. lung disease, GI obstruction)
CT scans → More detailed overview of disease extent & distribution
Ultrasound → Useful for soft tissue structures like bladder, liver & intestines
What samples might you collect during endoscopy of the respiratory tract?
Biopsy samples → Mucosal surfaces (for histopathology)
Bronchoalveolar lavage (BAL) → Collects fluid from lower respiratory tract to assess inflammation or infection
Brush cytology → Collects superficial cells from mucosa for cytology
What are the key steps before using endoscopy for gastrointestinal cases?
- Gather history & physical exam findings to justify use
2.Perform imaging:
- Radiographs → Detect FB, intussusception, gas patterns
- Ultrasound → Identify intestinal content, wall thickness & motility
- Minimum database (MDB) tests:
- CBC
- Biochemistry
- Urinalysis to rule out systemic disease
What samples can be collected during gastrointestinal endoscopy?
Mucosal biopsies for histopathology (inflammatory or neoplastic disease)
Foreign body retrieval (if present)
What are the potential complications of upper gastrointestinal endoscopy?
Bowel perforation (if excessive force is applied)
Aspiration of gastric contents
Damage to the endoscope
What are the key biopsy considerations during intestinal endoscopy?
Obtain perpendicular mucosal biopsies for accurate histopathology
Sample both stomach & small intestine (disease often diffuse)
Can’t access jejunum with standard endoscopy, which may limit findings
Why is endoscopy (cystoscopy) useful in evaluating chronic urinary disease?
Provides direct visualisation of urethra, bladder & trigone region
Helps differentiate between infectious, inflammatory & neoplastic disease
Allows biopsy of bladder mucosa for histopathology
Can sample uroliths or debris to aid diagnosis
What are the limitations of cystoscopy in diagnosing urinary tract disease?
Can’t assess kidney pathology directly
Lesions deeper in bladder wall may be missed as only mucosal surface is biopsied
Passing endoscope through narrowed or inflamed urethra may be difficult
