Contributors: James Simpson, Kenneth Simpson

 Species: Feline   |   Classification: Techniques

Introduction Requirements Preparation Procedure Aftercare Outcomes Further Reading

Introduction

  • Esophageal disease is rare in the cat but direct examination assists diagnosis.

Uses

  • Examination of the esophageal mucosal surface.
  • Collection of mucosal biopsy samples from the esophagus.
  • Detection Esophagus: foreign body - esophagoscopy 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 Esophagus: esophagitis - esophagoscopy .
  • Investigation of:

Advantages

  • Non invasive technique requiring no surgical intervention.
  • Well tolerated by sick cats 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 to assessing response to treatment.

Disadvantages

  • Will not detect pathology lying under the mucosa.
  • Cannot carry out surgical correction compared with thoracotomy.
  • Expensive equipment.

Technical Problems

  • Technical difficulty in procedures.

Alternative Techniques

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 (for foreign body retrieval) endoscope.
  • One meter insertion tube length.
  • 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 recording procedures and/or collecting still images.
    • Excellent as a training aid.
  • Xenon light source.
  • Insertion tube diameter 6-8 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 cart and sterilization unit.
  • 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 in a well ventilated area.
    • Do NOT store endoscopes in their carrying case.
    • See supplier for further details of endoscope 'hangers'.
  • Cleaning and disinfection Endoscope: cleaning:
    • Follow the manufacturers recommendations at all times.
    • Use an endoscope cleaning bath wherever possible.
    • Use whatever cleaning solution and disinfectant the manufacturer recommends.
    • 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 is essential to intubate patient with cuffed endotracheal tube.
  • Tie endotracheal tube to mandible not maxilla to assist with the passage of the endoscope.
  • Lay patient in left lateral recumbency.
  • Place mouth gag to protect endoscope.

Core Procedure

Step 1 - Endoscopic examination

  • Insert endoscope along hard palate and into proximal esophagus Esophagus: normal proximal - esophagoscopy .
  • Stop and gently inflate esophagus with air.
  • Once mucosa is visualized stop inflating with air.
    Do not over-inflate.
  • Slowly pass endoscope along the esophagus examining the mucosa as you proceed.
  • Examine the entire length of the esophagus.
  • Distal esophagus is recognized by presence of annular mucosal rings Stomach: normal fundus - gastroscopy   Esophagus: normal - esophagoscopy .

Step 2 - Biopsy collection

Esophagus is tough and difficult to biopsy.
  • Do not over-inflate esophagus as this will make mucosa stretch tightly reducing ability to collect samples.
  • Forceps with a needle may aid procurement of biopsies.
  • 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 can 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 mucus membrane color, heart and respiratory rates in case of hemorrhage.
  • Check there is no evidence of gastric dilation.

Special precautions

  • Do not over-inflate esophagus.
  • Apply only enough air to allow adequate visualization.

Potential complications

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

Outcomes

Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Kundrotas L W, Young G S, Lang K A et al (1995) Felinization of the esophagus. Gastrointest Endosc 42 (1), 37-40 PubMed.
  • Michels G M, Jones B D, Huss B T et al (1995) Endoscopic and surgical retrieval of fishhooks from the stomach and esophagus in dogs and cats - 75 cases (1977-1993). JAVMA 207 (9), 1194-1197 PubMed.

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 (1990) Small Animal Endoscopy. C V Mosby, St Louis.