Contributors: James Simpson, Kenneth Simpson
Species: Feline | Classification: Techniques
Introduction Requirements Preparation Procedure Aftercare Outcomes Further Reading
- Examination of the gastric mucosal surface.
- Collection of gastric mucosal biopsy samples.
- Detection and retrieval of gastric foreign bodies Stomach: gastric foreign body.
- PEG tube placement Gastrostomy: percutaneous tube (endoscopic).
- Investigation of:
- Vomiting Vomiting.
- Gastric neoplasia.
- Chronic gastritis Chronic gastritis.
- Gastric ulceration.
- Pyloric outflow disorders.
- Non-invasive technique requiring no surgical intervention.
- Well tolerated by sick cats which would be unsuitable for laparotomy.
- Requires only light general anesthesia - rapid recovery.
- Good visualization of the gastric 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 laparotomy.
- Expensive equipment.
- Technical difficulty in procedures.
- Radiography Radiography: abdomen and fluoroscopy contrast studies (barium series) fluoroscopy of the alimentary tract.
- Exploratory laparotomy Laparotomy: midline.
- Ultrasonography: detection of submucosal lesions and muscular hypertrophy. Gas can hamper evaluation.
- Induction of anesthesia and/or sedation → 10-30 min.
- Depends on the experience of the endoscopist → approximately 15-30 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 endoscope.
- Insertion tube diameter 6-8 mm.
- One meter insertion tube length.
- 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 video 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 and air.
- Cytology brushes, grasping forceps and balloon catheters.
- More than one endoscope for examination of different parts of the gastrointestinal tract.
- Endscope cleaning cart.
- Ultrasonic cleaner for biopsy forceps.
- Clean water.
- Endoscope cleaners and 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.
- 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 cleaners and disinfectant the manufacturer recommends.
- Follow health and safety rules regarding use of these products.
- Suitable premedication.
- Nil by mouth for a minimum of twelve hours, longer if there is delayed gastric emptying.
- General anesthesia.
Step 1 - Pass tube along esophagus
- Following induction of anesthesia - it is essential to intubate patient.
- Tie endotracheal tube to mandible to aid passage of endoscope.
- Lay patient in left lateral recumbancy.
- Place mouth gag to protect endoscope.
- Pass endoscope.
- Insert endoscope along hard palate and into proximal esophagus .
- Advance scope along length of esophagus (see Esophagoscopy Esophagoscopy).
Step 2 - Enter stomach
Step 1 - Examine rugae
- Only introduce enough air to visualize the mucosa.
- It is very important NOT to overdistend the stomach with air.
- Examine the rugal folds of the fundus .
Step 2 - Examine antral region
- Advance endoscope in the direction of the rugal folds. This will direct you towards the antrum.
- The angular incisure of the lesser curvature of the stomach will be seen as a band of mucosa and marks the entrance to the antrum .
This is an important endoscopic landmark.Rugal folds are NOT seen if stomach is overinflated with air.
- Retroflex the endoscope to visualize the cardia .
Step 3 - Examine pylorus
- Pass endoscope along antrum to visualize the pylorus .
- Bile may be observed entering the stomach as may antral peristaltic contraction.
These contractions are not seen if the stomach is overinflated.
Step 4 - Biopsy
- Collect biopsy samples from any focal lesions observed.
- In any case collect biopsy samples from the fundus, body, cardia and antrum.
- A minimum of 6 biopsy samples are required.
Always deflate the stomach with the endoscopic suction unit or stomach tube after the procedure.
- Do not overinflate the bowel 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.
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 overinflate stomach.
- Apply only enough air to allow adequate visualization.
- Always deflate the stomach after gastroscopy to reduce risk of gastric dilation.
- Arterial bleeding from biopsy sites.
- Gastric perforation from applying too much force.
- Iatrogenic damage to mucosa caused by advancing endoscope along gastric wall.
- Recent references from PubMed and VetMedResource.
Other sources of information
- Tams T R (1998) Small Animal Endoscopy. 2nd edn. C V Mosby, St Louis.
- 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.
- Brearley M, Cooper J E, Sullivan M (1991) A Colour Atlas of Small Animal Endoscopy. Wolfe.