Per-endoscopic trans-tympanic traction for the management of feline aural inflammatory polyps: a case review of 37 cats

Abstract

Feline aural inflammatory polyps are benign growths originating from the tympanic cavity or the Eustachian tube. They usually occur in young cats, which present either signs of otitis externa and otitis media, or respiratory signs, depending on the direction of polyp growth. Neurological signs are also reported. Simple traction and ventral bulla osteotomy (VBO) are the most common techniques used for treating this condition in cats; corticosteroids are recommended to reduce risk of recurrence given the inflammatory nature of the disease. The most common complications after treatment are Horner's syndrome, polyp recurrence and facial nerve paralysis. The aim of this report is to describe the per-endoscopic trans-tympanic traction (PTT) technique for treating feline aural inflammatory polyps and to report the short- and long-term follow-up of this procedure. PTT allowed resolution of the aural inflammatory polyps in 94% of cats during a mean long-term outcome of 19 months. Three cats (8%) developed Horner's syndrome immediately after the PTT procedure, which resolved within a few weeks, and five cats had polyp recurrence (13.5%). Only two cats had a poor outcome and were diagnosed with chronic otitis media at 22 months, and chronic otitis media and polyp recurrence at 46 months after the PTT procedure, respectively. PTT was shown to be an effective technique for treating aural inflammatory polyps and registered fewer neurological complications (8%) than VBO (57-81%) or simple traction (43%), and a recurrence percentage (13.5%) similar to VBO (0-33%) and much lower than traction alone (57%).

Figure 1

Radiological scoring of feline aural inflammatory polyps (10° rostrocaudal ventrodorsal view of the tympanic cavity). (a) Note the increased radiopacity of the left ear canal (white arrow) and middle ear cavity (thick black arrow) (case classified as ‘mild’); (b) Note the increased radiopacity of the left ear canal (white arrow) and middle ear cavity (thick black arrow), and the thickening of the bulla contour (thin black arrow) (case classified as ‘moderate’); (c) Note the increased radiopacity of the right ear canal (white arrow) and middle ear cavity, the severe bulla enlargement, the thickening of the septum (thin black arrow), and remodelling and the petrous bone involvement (short black arrow) (case classified as ‘severe’). The contralateral ear in every image is normal (courtesy of M Di Giancamillo)

Figure 2

(a) Endoscopic appearance of a feline aural inflammatory polyp: note the presence of a pinkish round mass occluding the horizontal ear canal. (b) Free ear canal after per-endoscopic trans-tympanic traction and at the top of the image the white aspect of the tympanic cavity after curettage; a moderate quantity of blood is still notable around the tympanic cavity and along the ear canal. On the left side within the bulla there is an artefact from saline solution reflecting the light of the endoscope