TECHNIQUE

Percutaneous Placement of Gastrotomy Tubes in Rabbits (Disease Investigation & Management - Treatment and Care)

Summary Information
Type of technique Health & Management / Disease Investigation & Management / Techniques:
Synonyms and Keywords --
Description
Preparation
  • Anaesthetise and intubate the rabbit.
  • Place the rabbit in right lateral recumbency.
  • Surgically prepare the left paracostal area.
  • Use strips of gauze to cover the rabbit's teeth and gently pull the jaws apart.
Placing the tube
  • Make a 3 mm incision 7.5 mm caudoventral to the greater curvature of the 12th rib to identify the site of cannula placement.
  • Lubricate the bronchoscope with 2% lidocaine hydrochloride gel.
    • This prevents activation of the hypersensitive pharyngeal reflex.
  • Insert the bronchoscope through the mouth and advance it through the oesophagus into the stomach.
  • Connect a hose to the biopsy port of the endoscope and, using a pump (aquarium air pump), distend the stomach with air.
    • Distending the stomach brings the stomach wall into contact with the left abdominal wall and displaces the liver, spleen and caecum away from the intended gastrotomy site.
  • Pass a 16-gauge Medicut tapered intravenous cannula through the skin incision and push it through the abdominal wall and gastric wall.
  • Remove the stylet.
  • Pass a polyester suture through the cannula into the stomach.
  • Visualise the suture in the stomach using the bronchoscope.
  • Grasp the suture with the snare of the bronchoscope.
  • Bring the end of the snare and suture to just inside the bronchoscope channel.
  • Bring the bronchoscope, with snare and suture, back out of the rabbit's mouth.
  • Remove the Medicut cannula from the abdominal wall and pass it over the end of the polyester suture.
  • Produce a 60 degree taper on the gastrostomy tube.
  • Suture the gastrostomy tube to the suture material.
  • Pull on the gastrostomy tube using the suture material, to stretch it, so that the funnel end of the Medicut cannula can fit over the tapered end of the tube..
  • Lubricate the cannula and gastrostomy tube.
  • Place tension on the suture from outside the body wall and pull the suture, cannula and attached gastrostomy tube through the mouth, oesophagus, stomach, gastric wall and abdominal wall.
  • Reintroduce the bronchoscope into the stomach and confirm the placement of the gastrostomy tube.
  • Apply traction on the gastrostomy tube to ensure the gastric wall and abdominal wall are in contact.
  • Fix the tube externally by passing a flange (made from the wide connecting end of the catheter) over the tube and in close contact with the abdominal wall.
    • This prevents inward movement of the tube.
  • Place tape around the gastrotomy tube next to the flange to keep it in position.
  • Close the tube with a three-way stopcock.
Protecting the tube
  • Place a stockinette jacket (4 inch stockinette, doubled and with holes cut for the forelimbs and the tube) onto the rabbit.
  • Or It may be possible to shorten the tube, fit an intermittent injection port and not use a stockinette jacket.
  • Consider fitting a collar (Elizabethan or soft collar). See: Treatment and Care - Wound Management
    • Elizabethan collars appear to depress rabbits.
    • A collar may not be needed; experimentally, most rabbits did not remove bother the tube.
  • Monitor the PEG incision site and clean the skin around the site daily.
  • Keep the rabbit in a smooth-sided cage lacking sites on which the tube could catch.
  • Consider giving appropriate systemic broad-spectrum antibiotics 
Feeding
  • Feed through the tube.
    • Food must be well-blended and warmed to at least room temperature before feeding.
  • N.B. consider the maximum stomach capacity of the rabbit when considering how much to give at one time.
  • Offer food as well.
Removal of the tube
  • Sedation is not required.
  • Remove the tube by pulling with steady traction while placing firm counter-pressure on the adjacent skin.
    • This may require more pressure than expected.
    • Rabbits did not show signs of discomfort during this procedure.
  • Leave the tube for sufficiently long (14 days) that fibrous adhesions will have formed between the stomach and abdominal wall, preventing peritonitis when the tube is withdrawn.

(J521.22.w1, J521.33.w1)

Appropriate Use (?)
  • To allow enteral nutritional support of anorectic rabbits, e.g. in the medical management of gastric stasis. (J521.33.w1)
  • For long-term, large-volume or frequent gastric dosing of medication. (J521.33.w1)
Notes --
Complications/ Limitations / Risk In experimental use of a percutaneously placed gastrotomy tube in five rabbits:
  • The skin around the tube was warm and reddened for about 5-6 days after tube insertion.
  • The flange tended to become adherent to the skin; daily cleaning was needed.
  • In two rabbits, superficial necrosis developed on the skin under the flange; the affected area was cleaned with hydrogen peroxide and the flange slightly loosened.
  • In all rabbits, a rim of granulation tissue formed around the tube by one week, with increased superficial scaling of the surrounding skin.
  • In two rabbits, a small amount of purulent exudate developed around the tube at day 10; culture revealed Staphylococcus aureus and, in one rabbit, Escherichia coli.
    • Cleaning with hydrogen peroxide resolved the infections.
  • Rabbits started eating pellets voluntarily within three days of tube placement.
  • Rabbits showed a slight weight loss initially, then regained weight to pre-operative values by three to eight days post operation.
  • After the tubes were removed, wound closure was immediate but with serum leakage and, in two cases purulent exudate for one day.
    • Cleaning with hydrogen peroxide was effective.
  • At necropsy, fibrous adhesions were confirmed, connecting the stomach wall to the abdominal wall.

(J521.33.w1)

Equipment / Chemicals required and Suppliers
  • 16-French de Pezzer (mushroom) catheter, modified by cutting the small, bulb end off to improve passage of food through the catheter, and by cutting off the wide connecting end. (J521.33.w1)

  • 16-gauge tapered intravenous catheter. (J521.33.w1)

  • Bronchofibrescope with biopsy forceps. (J521.33.w1)

  • 1 m of 0 polyamide. (J521.33.w1)

Expertise level / Ease of Use
  • This procedure should only be carried out by an individual with appropriate clinical training and practical experience.
Cost/ Availability --
Legal and Ethical Considerations In some countries there may be legislation restricting the use of this type of technique to licensed veterinarians. For example in the UK: "The Veterinary Surgeons Act 1966 (Section 19) provides, subject to a number of exceptions, that only registered members of the Royal College of Veterinary Surgeons may practice veterinary surgery." (See: LCofC1 - RCVS Guide to Professional Conduct 2000 - Treatment of Animals by Non-Veterinary Surgeons).
Author Debra Bourne MA VetMB PhD MRCVS (V.w5)
Referee Frances Harcourt-Brown BVSc FRCVS (V.w140)
References J521.33.w1

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