Bulla Osteotomy in Rabbits (Disease Investigation & Management - Treatment and Care)

Summary Information
Type of technique Health & Management / Disease Investigation & Management / Techniques:
Synonyms and Keywords --
Description Based predominantly on the description given by Mehler (2006). (B601.17.w17)
  • Anaesthetise the rabbit. See: Treatment and Care - Anaesthesia and Chemical Restraint - Lagomorph Anaesthesia
  • Shave and aseptically prepare the area around the base of the ear.
    • Transparent drapes may be placed around the surgical site.
  • Place the rabbit in dorsal recumbency with support under the neck so the neck can be extended.
  • Use palpation to identify the angle of the caudal mandible, the wings of the atlas, and the tympanic bulla.
    • The tympanic bulla is found below the cartilaginous floor of the external canal of the ear. (B615.8.w8)
  • Make a skin incision from just caudal to the angle of the mandible to just cranial to the wing of the atlas.
  • Continue the incision through the subcutaneous tissue.
  • Identify the digastricus muscle, hypoglossal muscle and hypoglossal nerve.
  • Gently retract the hypoglossal nerve away from the surgical field.
  • Bluntly dissect down to the ventral wall of the tympanic bulla.
    • Keep directly over the bulla during the blunt dissection.
    • Identify the tendon crossing over the ventral surface of the bulla - entry into the bulla should take place medial to the tendon.
  • Make a hole in the ventromedial aspect of the bulla using a pneumatic burr or a small Steinmann pin. (B601.17.w17, B615.8.w8)
  • Use small rongeurs to enlarge the hole on the ventromedial aspect of the bulla.
  • Take samples for bacterial culture, cytology and histopathology,
  • Gently lavage the bulla using copious quantities of sterile fluid.
  • Remove the inner epithelial lining of the bulla by careful scraping with a bone curette.
    • Removal of all the lining is important to avoid recurrence of infection
    • Avoid the dorsomedial compartment of the bulla, to ensure that the inner ear is not damaged during this process.
  • Lavage the bulla.
  • If required, implant a ventrally draining silicone tube drain. (B615.8.w8)
    • Flush the drain daily for 3-5 days, then remove the tube. (B615.8.w8)
    • An Elizabethan collar may be needed to avoid the rabbit scratching out the tube. (B615.8.w8)
  • Close the subcutaneous tissue.
  • Close the skin.

(B601.17.w17, B615.8.w8, P3.2008a.w1)

Post-operative care
  • See: Treatment and Care - Surgery - Post-operative care
  • Initiate or continue analgesia, antibiotic treatment, anti-nausea treatment and medical management of ileus. (B601.17.w17)
  • Monitor for signs of: (B601.17.w17)
    • Horner's syndrome
    • Hypoglossal nerve defects.
    • Increased head tilt.
    • Torticollis
    • Progressive ileus.
Appropriate Use (?)
  • Otitis media associated with signs such as head tilt, opisthotonus, horizontal nystagmus and anorexia (B600.12.w12) which is not improving with medical treatment. (B601.17.w17)
  • Neoplasia affecting the bulla. (B601.17.w17)
Notes --
Complications/ Limitations / Risk
  • There is a high risk of post-operative complications. (J15.28.w1) These may include:
    • Horner's syndrome. (J15.28.w1)
    • Hypoglossal nerve defects. (J15.28.w1)
    • Increased head tilt. (J15.28.w1)
    • Torticollis. (J15.28.w1)
    • Progressive ileus. (J15.28.w1)
    • Self-mutilation. (B601.17.w17)
    • Cellulitis. (B601.17.w17)
Equipment / Chemicals required and Suppliers
  • Standard anaesthetic equipment

  • Surgical equipment, including a pneumatic burr or a small Steinmann pin, small rongeurs and a bone curette of appropriate size.

  • Suture materials.

Expertise level / Ease of Use
  • This procedure should only be carried out by an individual with appropriate clinical training and practical experience.
Cost / Availability
  • Availability of an appropriately trained veterinary surgeon.
  • Costs of anaesthesia and surgery.

The costs of a surgical operation include those associated with: (J15.30.w1)

  • Pre-operative diagnostics (e.g. radiography, ultrasonography, blood tests)
  • Anaesthesia.
  • Perioperative medication (e.g. analgesics, antibiotics, fluids).
  • Surgical preparation (of the operating theatre and the patient, including staff time).
  • Consumables and equipment.
  • Time of the surgeon and assistant(s).
  • Post-operative hospitalisation.
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 B600.12.w12, B601.17.w17, B615.8.w8, J15.28.w1, J15.30.w1, P3.2008a.w1

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