Contributors: James Simpson, Kenneth Simpson
Species: Feline | Classification: Techniques
- Esophageal disease is rare in the cat but direct examination assists diagnosis.
- Examination of the esophageal mucosal surface.
- Collection of mucosal biopsy samples from the esophagus.
- Detection 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:
- Regurgitation Regurgitation.
- 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.
- Will not detect pathology lying under the mucosa.
- Cannot carry out surgical correction compared with thoracotomy.
- Expensive equipment.
- Technical difficulty in procedures.
- Induction of anesthesia and/or sedation → 10-30 min.
- Depends on the experience of the endoscopist → esophagoscopy approximately 10 min.
- Low risk.
- See complications.
- 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.
- 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.
- 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.
- Clean water.
- Endoscope disinfectants.
- Household detergent.
- Formal saline, card and containers for preservation of biopsy samples.
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.
- Suitable pre-medication Anesthetic premedication: overview.
- Nil by mouth for 6 hours prior to procedure.
- Light general anesthesia General anesthesia: overview.
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.
Step 1 - Endoscopic examination
- Insert endoscope along hard palate and into proximal esophagus .
- 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 .
Step 2 - Biopsy collectionEsophagus 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.
Step 1 - Remove endoscope
- Gently withdraw endoscope.
- Support end of scope as it is withdrawn to prevent damage.
- Routine post anesthetic observation.
- Check mucus membrane color, heart and respiratory rates in case of hemorrhage.
- Check there is no evidence of gastric dilation.
- Do not over-inflate esophagus.
- Apply only enough air to allow adequate visualization.
- Esophageal perforation from applying too much force
- Iatrogenic damage to mucosa caused by advancing endoscope along esophagus.
- 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.