Rigid VS Flexible Scopes

Question 1

What is a Flexible Endoscope?

Answer 1

Long flexible device with a distal “bendable” end controlled from a handpiece

Question 2

What are the two categories of flexible endoscopes?

Answer 2

Fibreoptic endoscopes
Pixelated images and/or damage to optic fibres reduces image quality

Video endoscopes
Superior image quality
Reduced repair costs

Question 3

Main Components of Flexible Endoscope

Answer 3

Insertion tube
○ Fragile
Handpiece
○ Control section
○ Knobs control bendable end of the scope (up/down; left/right; full retroflexion 180-210°)
○ Air/water and suction buttons
○ Instrument/biopsy channel with rubber cap to allow insufflation
Light guide connector (umbilical or universal cord)

Question 4

When do we use flexible endoscopy?

Answer 4

• GI endoscopy
  ○ Good practice would be to examine duodenum/upper small intestine as well as stomach
  ○ Outer diameter <10mm
  ○ Working length >150cm
• Bronchoscope
  ○ Outer diameter <3-5mm
• Nasopharynx
  ○ Retroflexed scope to look above soft palate for grass foreign bodies
• Urethroscopy/cystoscopy in male dogs

Question 5

Limitations of Flexible Endoscopy

Answer 5

• Even long scopes might not be long enough
• Small diameter scopes only allow small biopsy instruments
• Biopsy channel needs to be approx. 2.8mm to be useful

Question 6

Rigid Endoscopy

Answer 6

• No flexibility means restricted in access to some anatomical sites
• Cheaper and less prone to damage than flexible scopes
• Superior image compared with most flexible scope systems
• Allows larger instruments to be used alongside the scope
  ○ not usually limited by size of biopsy channel
• Variety of sizes: typical example
  ○ Outer diameter 2.7mm; length 18cm; viewing angle 30°
• Additional equipment required:
  ○ Sheaths
  Protect the scope
  Allow fluids to pass through side ports

Question 7

When do we use Rigid Endoscopy?

Answer 7

• Rhinoscopy
  ○ +/- flexible endoscopy for the caudal nasopharynx
• Arthroscopy
• Cystoscopy in bitches
• Laparoscopy

Question 8

Limitations of Rigid Endoscopy

Answer 8

• 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