Carbon dioxide laser surgery for chronic proliferative and obstructive otitis externa in 26 dogs.

Abstract

Some dogs with chronic otitis externa (OE) develop proliferation of the tissues surrounding the opening of the external ear canal, resulting in obstruction. Traditionally total ear canal ablation with bulla osteotomy (TECABO) has been recommended. To evaluate the efficacy of a novel treatment using carbon dioxide (CO2 ) laser surgery and to describe the histopathological features of chronic proliferative and obstructive OE. Twenty-six dogs were included, 16 with bilateral and 10 with unilateral disease (42 ears were treated). Dogs with nonpatent horizontal ear canal or macroscopic calcification of the ear canal were excluded. For histopathological evaluation, tissue samples were collected from 11 dogs (17 ears). Hyperplastic tissue around the canal opening and within the vertical ear canal was dissected and ablated using a CO2 laser. Biopsy samples were evaluated for sebaceous and ceruminous gland hyperplasia, epidermal hyperplasia, inflammation and fibrosis. Following CO2 laser surgery there was a good or excellent outcome with substantial resolution of proliferative changes in 39 of 42 ears from 24 of 26 dogs. One surgery was sufficient in 21 dogs and three dogs had two surgeries. Two dogs had recurrence of proliferative tissue after one surgery and underwent TECABO. Two dogs had no recurrence of proliferative tissue after surgery, yet had persistent luminal infection and underwent TECABO. The remainder of the dogs were effectively medically managed long-term following surgery. Histologically, eight ears had a predominantly sebaceous gland response, three had a predominantly ceruminous response and six had a mixed glandular pattern. Epidermal hyperplasia, inflammation and fibrosis varied from mild to severe. Carbon dioxide laser surgery is an effective treatment of proliferative OE causing obstruction of the ear canal opening and vertical canal, and should be considered as an alternative to TECABO whenever possible.