Management of feline ent neoplasia

摘要

Feline ear surgery is most commonly indicated in the treatment of neoplasia, notably ceruminous adenocarcinoma and squamous cell carcinoma (SCC). The lesion may be restricted to the pinna, and, in the case of SCC may be secondary to actinic keratitis seen primarily in white haired cats. Wide local resection in the form of a pinnectomy can be performed using sharp dissection or carbon dioxide laser. Lateral wall resection may be indicated in the treatment of neoplasia limited to the lateral verticalcanal wall. If the medial vertical canal wall, or the entire vertical canal is diseased, and the horizontal canal is normal, a vertical canal ablation can be performed. This scenario is not particularly common. Total Ear Canal ablation is indicated forneoplasia involving both these portions of the ear canal or where a less aggressive surgical procedure may risk duly surgical margins. A thorough knowledge of the local anatomy is essential, particularly the course of the facial nerve. Facial nerve paralysis following surgery is a known but uncommon complication, however neuropraxia and paresis following canal dissection is not uncommon and should be discussed with the owner prior to surgery as the ipsilateral eye may require temporary corneal lubrication. It can last anywhere from a few days to a few weeks. Meticulous resection of all soft tissue associated with the junction between bulla and horizontal canal is imperative to prevent the formation of para-aural abscesses or fistulous tracts. A lateralbulla osteotomy is routinely performed and the epithelial lining, inflammatory debris and any neoplastic tissue from within the bulla completely removed. Neoplastic invasion of the bulla will limit the surgical margin and potentially necessitate postoperative radiotherapy. Cultures should be taken from the bulla where appropriate. Vestibular signs or Horner's syndrome are usually transient complications when they occur and can often benefit from a course of oral steroids.