Contributors: James Simpson, Kenneth Simpson

 Species: Canine   |   Classification: Techniques

Introduction Requirements Preparation Procedure Aftercare Outcomes Further Reading

Introduction

Uses

  • Examination of the esophageal mucosal surface.
  • Collection of mucosal biopsy samples from the esophagus.
  • Detection Esophagus foreign body 2 radiograph lateral and retrieval of foreign bodies Esophagus: foreign body from the esophagus.
  • Esophageal stricture dilatation Esophagus: stricture.
  • Detection/biopsy of esophageal masses.
  • Definitive diagnosis of esophagitis.
  • Investigation of:

Advantages

  • Non-invasive technique requiring no surgical intervention.
  • Well tolerated by sick dogs which would be unsuitable for esophagostomy.
  • Requires only light general anesthesia - rapid recovery.
  • Good visualization of the esophageal mucosa.
  • Follow up examination well tolerated and useful for assessing response to treatment.

Disadvantages

  • Will not detect pathology lying under the mucosa.
  • Cannot carry out surgical correction compared with thoracotomy but can remove esophageal foreign bodies.
  • Expensive equipment.

Technical Problems

  • Technical difficulty in procedures.

Alternative Techniques

  • Radiography Radiography: thorax , fluoroscopy and contrast studies (barium series) fluoroscopy of the esophagus.
  • Exploratory thoracotomy and esophagostomy Esophagostomy.

Time Required

Preparation

  • Induction of anesthesia and/or sedation → 10-30 min.

Procedure

  • Depends on the experience of the endoscopist → esophagoscopy approximately 10 min.

Decision Taking

Risk assessment

  • Low risk.
  • See complications.

Requirements

Personnel

Nursing expertise

  • Good level of competence required for assisting in procedures, monitoring anesthetic and assisting in biopsy collection and handling.
  • High competence for care and cleaning of endoscopic equipment.

Materials Required

Minimum equipment

  • Fully immersible fiber-optic, flexible or rigid Endoscopy rigid open esophagoscope (for foreign body retrieval) endoscope.
  • One meter insertion tube length (depending on size of patient).
  • Insertion tube diameter 7-9 mm.
  • ONLY use an end viewing endoscope.
  • Four way tip deflection.
  • MUST have cold light source with air pump and water wash facility.
  • Fenestrated biopsy forceps for collection of mucosal biopsy samples.
  • Cleaning brushes for biopsy channels.
  • Water leakage tester.

Ideal equipment

  • video endoscope:
    • Excellent magnified image presented on screen.
    • Detection of lesions much easier.
    • Allows for multiple person viewing.
    • Excellent for video recording procedures and/or collecting still images.
    • Excellent as a training aid.
  • Xenon light source.
  • Insertion tube diameter 7-9 mm.
  • Suction unit for aspiration of unwanted gastrointestinal secretions.
  • Cytology brushes, grasping forceps and balloon catheters.
  • More than one endoscope for examination of different parts of the gastrointestinal tract.
  • Endoscope cleaning trolly.
  • Ultrasonic cleaner for biopsy forceps.

Minimum consumables

  • Clean water.
  • Endoscope disinfectants.
  • Household detergent.
  • Formal saline, card and containers for preservation of biopsy samples.

Other requirements



Care and maintenance
  • Storage of endoscopes:
    • ALWAYS store endoscopes in a safe location where accidental knocks can be avoided.
    • ALWAYS store endoscopes with insertion tube hanging vertically.
    • Do NOT store endoscopes in their carrying case.
    • See supplier for further details of endoscope 'hangers'.
  • Cleaning and disinfection:
    • Follow the manufacturers recommendations at all times.
    • Use an endoscope cleaning bath wherever possible.
    • Use whatever disinfectant the manufacturer recommends. Gigasept, Cidex and Dettol endoscopic disinfectants are available.
    • Follow health and safety rules regarding use of these products.

Preparation

Pre-medication

Dietary Preparation

  • Nil by mouth for 6 hours prior to procedure.

Restraint

Procedure

Approach

Step 1 - Patient preparation

  • Following induction of anesthesia - it isessentialto intubate patient.
  • Tie endotracheal tube to mandible (not maxilla) to assist with the passage of the endoscope.
  • Lay patient in left lateral recumbancy.
  • Place mouth gag to protect endoscope.

Core Procedure

 

Step 1 - Endoscopic examination

 
  • Insert endoscope along hard palate Endoscopy introduction of esophagoscope over larynx and into proximal esophagus Endoscopy introduction of esophagoscope into esophagus.
  • Stop and gently inflate esophagus with air.
  • Once mucosa is visualized stop inflating with air.
    Do not overinflate.
  • Slowly pass endoscope along the esophagus examining the mucosa as you proceed.
  • Examine the entire length of the esophagus.

Step 2 - Biopsy collection




Esophagus is tough and difficult to biopsy.
  • Do not overinflate esophagus as this will make mucosa stretch tightly reducing ability to collect samples.
  • Try and advance biopsy forceps perpendicular to the mucosa.
  • Tent mucosa before closing biopsy forceps and retrieving sample.
  • Deeper samples can be collected by sampling repeatedly at the same site.
  • Perforation will occur if this is done too frequently.
  • Capillary bleeding from biopsy sites is normal.

Exit

 

Step 1 - Remove endoscope

 
  • Gently withdraw endoscope.
  • Support end of scope as it is withdrawn to prevent damage.

Aftercare

Immediate

General Care

  • Routine post-anesthetic observation.
  • Check mucous membrane color, heart and respiratory rates in case of hemorrhage.
  • Check there is no evidence of gastric dilation.

Special precautions

  • Do not overinflate esophagus.
  • Apply only enough air to allow adequate visualization.

Potential complications

  • Arterial bleeding from biopsy sites.
  • Esophageal perforation from applying too much force.
  • Iatrogenic damage to mucosa caused by advancing endoscope along esophagus.

Outcomes

Further Reading

Publications

Refereed papers

Other sources of information

  • Simpson J W (1996)Gastrointestinal Endoscopy.In:Manual of Canine and Feline Gastroenterology.Eds D Thomas, J W Simpson & E J Hall. BSAVA, Cheltenham. pp 20.
  • Tams T R (1998)Small Animal Endoscopy.2nd edn. St Louis: C V Mosby.