Total ear canal ablation in the cat: indications, morbidity and long-term survival

Fifty-two total ear canal ablation (TECA) procedures in 44 cats were reviewed. The indication for surgery was neoplasia in 41 per cent of the cats, 86 per cent of which had ceruminous gland adenocarcinoma. Chronic inflammatory or polypoid disease accounted for 50 per cent of surgical procedures. Postoperative complications included Horner's syndrome (42 per cent) and facial paralysis (56 per cent) and these were permanent in 14 per cent and 28 per cent of cases, respectively, with the rest resolving in the ensuing weeks or months. The higher incidence of Horner's syndrome and facial paralysis in the cat, compared to the dog, was attributed to greater fragility of the feline tympanic plexus and facial nerve. The median survival time of cats with ceruminous gland adenocarcinoma was 50-3 months, and did not differ significantly from that for inflammatory or polypoid disease. A potential prognostic indicator for this tumour was the mitotic index (MI): cases with MI < or = 2 survived significantly longer than those with MI > or = 3.     

Cosmetic results of a ventrally based advancement flap for closure of total ear canal ablations in 6 cats: 2002-2003

OBJECTIVE: To report the outcome of a modified total ear canal ablation (TECA) technique to maintain normal ear carriage in cats. STUDY DESIGN: Case series. ANIMALS: Six cats with external ear canal disease. METHODS: Medical records were reviewed to identify cats in which a modified TECA using a single pedicle advancement flap was used to maintain normal ear carriage. Signalment, histopathologic diagnosis, complications, and outcome were retrieved. Owners were contacted to document long-term outcome. RESULTS: Modified TECA procedures (7) were performed in 6 cats. Normal ear carriage was present immediately after surgery and was preserved at follow-up interview. Owners were satisfied with cosmetic appearance. Histopathologic diagnosis of excised ear masses included ceruminous gland adenocarcinoma (2 cats), ceruminous gland adenoma (2 cats, 3 ears), and inflammatory polyp (2 cats). CONCLUSIONS: Modification of the TECA skin incision preserved normal ear carriage in all cats. Owners were satisfied with overall outcome and with cosmetic result. Rate and nature of complications were similar to previously published data. CLINICAL RELEVANCE: A simple modification of the TECA skin incision to create a single pedicle advancement flap maintains normal ear carriage in cats.     

Para-aural abscessation following traumatic ear canal separation in a dog

Traumatic ear canal separation is rare in animals, with only eight dogs and one cat reported with the condition in the English language literature. Para-aural abscessation occurred in six of these nine animals. Diagnosis was made on otoscopic observation of a shortened, abruptly ending external ear canal that was free from advanced disease. Radiographs in those cases which have been described showed a disruption of the normal air opacity of the affected ear canal. Drainage, by creating a separate opening for the horizontal ear canal, or total ear canal ablation and lateral bulla osteotomy (TECA/LBO), have led to resolution of the clinical signs. This report adds a further case to the literature in which TECA/LBO was employed successfully.     

Surgical management of 43 cases of chronic otitis externa in the dog

: Over a seven-year period, chronic otitis externa was surgically managed in 43 dogs at the University Veterinary Hospital of University College Dublin. Lateral ear canal resection (LECR) was undertaken in nine of the 43 dogs: results were unsatisfactory, with a failure of the surgery in five of eight dogs and one dog lost to follow-up. Once end-stage otitis externa, with or without otitis media, is diagnosed, total ear canal ablation and lateral bulla osteotomy (TECA/LBO) is the best treatment option. In this series, 37 of 43 dogs underwent TECA/LBO and of the 29 dogs for which follow-up results were obtained 27 (93%) had an excellent or improved outcome to surgery. Complications following all procedures were most common in cases with a concurrent dermatopathy; therefore, definitive diagnosis and medical treatment for skin and ear disease is essential.     

Cholesteatoma after lateral bulla osteotomy in two brachycephalic dogs

This report describes a French bulldog and a pug that presented to the authors' hospital following total ear canal ablation (TECA) and lateral bulla osteotomy (LBO), with signs of recurring otitis media and difficulty opening their mouths. The bulldog also had unilateral facial paralysis and sensory deficits of the trigeminal nerve on the ipsilateral side. Computed tomography and MRI scans suggested cholesteatoma in the bulldog, but showed only slight enlargement of the bulla in the pug. Histopathologic examination of samples yielded cholesteatoma in both cases. The authors suspect that development of the cholesteatomas was linked to the TECA/LBO surgery in both cases. Cholesteatomas may occur more frequently than currently thought. Even if only slight changes of the bulla wall are detected on CT, early-stage cholesteatoma should be considered. The narrow anatomic conditions in brachycephalic dogs possibly predispose such breeds to develop cholesteatoma after middle ear surgery because complete removal of all inflammatory and epithelial tissue can be more difficult than in other breeds. To the authors' knowledge, this is the first report of an aural cholesteatoma causing sensory deficits of the trigeminal nerve.     

Total Ear Canal Ablation Clinical Results in the Dog and Cat

The clinical results of 39 consecutive ear ablations (in 28 dogs and three cats) performed over a 15-year period were reviewed. Indications for ear canal ablation included hyperplastic tissue stenosis of the horizontal ear canal (23), failed lateral ear resections (13), and horizontal ear canal neoplasms (3). Ear ablation was successful in alleviating persistent signs of otitis in eight of 15 dogs with horizontal ear canal stenosis due to hyperplastic tissue, seven of 10 dogs with unsuccessful lateral ear resections, and two of five animals (three cats and two dogs) with horizontal ear canal neoplasms (follow-up time periods greater than 5 months). Surgical complications occurred following 82% of the ablations; wound infections (41%) and facial nerve damage (36%) were most common. Local wound and antibiotic therapy successfully treated prolonged drainage following ablation in five of nine dogs. Bulla osteotomy and drainage were successful in the treatment of three dogs (four ears) that were unresponsive to medical therapy with postoperative ear fistula following ablation, one of two dogs with prolonged ear drainage following ablation for failed lateral ear resection, and one dog with recurrence of signs of inner ear disease following ablation (follow-up period, 1 month to 4 years; mean, 3.4 years). Facial nerve damage caused by ablation was transient in nine of 14 ears, with most deficits returning to normal within 2 weeks.     

Total ear canal ablation and lateral bulla osteotomy in the dog

One hundred total ear canal ablation/lateral bulla osteotomy procedures were performed in 71 dogs over a four year period. The main indication for surgery was advanced disease of the aural canal or middle ear resulting from prolonged inflammatory disease of the outer ear. Complications of surgery included facial nerve injury, inner ear injury, retroglenoid vein haemorrhage and wound dehiscion. The incidence of complications (29 per cent) was, however, substantially lower than has previously been recorded following this procedure. Meticulous dissection technique and increasing familiarity with the procedure were thought to be responsible for lower complication rates than have previously been recorded. Surgery was considered to have resolved the original aural condition in 92 per cent of cases and only infrequently resulted in complete loss of hearing function.     

MAGNETIC RESONANCE IMAGING OF THE NORMAL AND DISEASED FELINE MIDDLE EAR

The magnetic resonance imaging appearance of the feline middle ear is described in three healthy cats and in five cats with middle ear disease. Owing to the good spatial resolution, multiplanar slice orientation as well as display high contrast resolution of soft tissue, in particular fluids, MR imaging was helpful prior to surgery. It is superior to radiography which failed to allow identification of the abnormality in two of our five cats. MR imaging for middle ear disease should include dorsal and transverse plane images using T1- and T2-weighted sequences. In the presence of a mass within the bulla or the external ear canal application of contrast medium is helpful.     

Effect of tympanic cavity evacuation and flushing on microbial isolates during total ear canal ablation with lateral bulla osteotomy in dogs

OBJECTIVE: To evaluate differences in bacterial numbers, identity, and susceptibility in samples obtained from the tympanic cavity on entry (preflush) and after evacuation and lavage (postflush) and assess perioperative and empiric antimicrobial selection in dogs that underwent total ear canal ablation (TECA) with lateral bulla osteotomy (LBO) or reoperation LBO. DESIGN: Prospective clinical study. ANIMALS: 34 dogs. PROCEDURE: TECA with LBO or reoperation LBO was performed on 47 ears. Pre- and postflush aerobic and anaerobic samples were obtained from the tympanic cavity. Isolates and antimicrobial susceptibility patterns were compared. RESULTS: Different isolates (31/44 [70%] ears) and susceptibility patterns of isolate pairs (6/44 [14%] ears) were detected in pre- and postflush samples from 84% of ears. Evacuation and lavage of the tympanic cavity decreased the number of bacterial isolates by 33%. In 26% of ears, bacteria were isolated from post-flush samples but not preflush samples. Only 26% of isolates tested were susceptible to cefazolin. At least 1 isolate from 53% of dogs that received empirically chosen antimicrobials postoperatively was resistant to the selected drugs. Anaerobic bacteria were recovered from 6 ears. CONCLUSIONS AND CLINICAL RELEVANCE: Accurate microbiologic assessment of the tympanic cavity should be the basis for selection of antimicrobials in dogs undergoing TECA with LBO. Bacteria remain in the tympanic cavity after evacuation and lavage. Cefazolin was a poor choice for dogs that underwent TECA with LBO, as judged on the basis of culture and susceptibility testing results.     

Neoplasia involving the middle ear cavity of dogs

Eleven cases of neoplasia which involved the middle ear cavity of dogs are recorded. Eight of the tumours originated in the external ear canal and comprised four adnexal tumours, one squamous papilloma and three adenocarcinomas of the ceruminous glands. Papillary adenomas were recognised within the middle ear cavity of two dogs. In one animal the precise origin of an anaplastic carcinoma involving the middle ear could not be determined. Only five of the tumours were amendable to surgical excision and four dogs survived for more than eight months after surgery.     

Aural Cholesteatoma in Twenty Dogs

Objective— To determine the clinical course in dogs with aural cholesteatoma. Study Design— Case series. Animals— Dogs (n=20) with aural cholesteatoma. Methods— Case review (1998–2007). Results— Twenty dogs were identified. Clinical signs other than those of chronic otitis externa included head tilt (6 dogs), unilateral facial palsy (4), pain on opening or inability to open the mouth (4), and ataxia (3). Computed tomography (CT) was performed in 19 dogs, abnormalities included osteoproliferation (13 dogs), lysis of the bulla (12), expansion of the bulla (11), bone lysis in the squamous or petrosal portion of the temporal bone (4) and enlargement of associated lymph nodes (7). Nineteen dogs had total ear canal ablation–lateral bulla osteotomy or ventral bulla osteotomy with the intent to cure; 9 dogs had no further signs of middle ear disease whereas 10 had persistent or recurrent clinical signs. Risk factors for recurrence after surgery were inability to open the mouth or neurologic signs on admission and lysis of any portion of the temporal bone on CT imaging. Dogs admitted with neurologic signs or inability to open the mouth had a median survival of 16 months. Conclusions— Early surgical treatment of aural cholesteatoma may be curative. Recurrence after surgery is associated with advanced disease, typically indicated by inability to open the jaw, neurologic disease, or bone lysis on CT imaging. Clinical Relevance— Presence of aural cholesteatoma may affect the prognosis for successful surgical treatment of middle ear disease.     

Total Ear Canal Ablation Combined with Lateral Bulla Osteotomy for End-Stage Otitis in Dogs Results in Thirty Dogs

Thirty dogs with end-stage otitis were treated by either unilateral or bilateral total ear canal ablation and lateral bulla osteotomy. Otitis was considered end stage when the horizontal ear canal was collapsed, stenotic, or occluded in conjunction with chronic infection of the external and middle ear. The dogs were evaluated clinically and radiographically for 4 to 63 months. The frequency of scratching, head shaking, aural drainage, and para-aural fistulation was significantly decreased. Abnormal ear carriage and head tilt were not changed. The results in 23 dogs were graded as excellent or improved. One dog died of intraoperative hemorrhage. Complications during the period from suture removal to follow-up included para-aural fistulation (3 dogs), facial nerve paralysis (5 dogs), and head tilt (3 dogs).     

Separation of the Auricular and Annular Ear Cartilages: Surgical Repair Technique and Clinical Use in Dogs and Cats

Objective— To report a surgical technique for primary repair of separation of the annular and auricular cartilages of the ear and long-term outcome.
Study Design— Case series.
Animals— Cats (3) and dogs (2) with ear canal separation.
Methods— Medical records (1998–2007) of dogs and cats with ear canal separation were reviewed. Long-term outcome was obtained by telephone interview of owners or referring veterinarians.
Results— Three cats and 1 dog had ear canal separation after being hit by a car; there was no history of trauma in 1 dog. Successful repair was achieved by a caudal approach to the ear canal, identifying and debriding separated cartilage edges and using primary repair. A patent ear canal was confirmed in all animals by otoscopy 4–12 weeks later and by ear canalography in 3 animals. Long-term outcome was excellent with no reported complications 10–90 months later (median 24 months).
Conclusions— Both acute and chronic separation between the annular and auricular cartilages, in the absence of middle ear disease, can be successfully treated using primary repair via a caudal approach to the ear canal, with excellent long-term outcome.
Clinical Relevance— Primary repair should be considered in animals with separation of the annular and auricular cartilages.     

COMPUTED TOMOGRAPHIC APPEARANCE OF INFLAMMATORY POLYPS IN THREE CATS

This report describes the use of computed tomography (CT) to evaluate the inner ear, tympanic bullae, nasopharyngeal area, and external ear canals of three cats. All cats presented for evaluation of upper respiratory signs or chronic ear infection. Nasopharyngeal masses were present in two cats, and a mass in the external ear canal was present in the third cat. In all three cats, CT was able to define the extent of osseous bulla involvement, which was confirmed at surgery. Computed tomography also defined the extent of the polyp in the nasopharyngeal area in two cats, and in the external ear canal in one cat. Surgical removal of the polyps was accomplished with a combined oral approach and ventral bulla osteotomy in cats 1 and 2. The polyp was removed from cat 3 using a combination of ventral bulla osteotomy and excision of the mass through the external ear canal. Microscopic examination confirmed all masses as nasopharyngeal (inflammatory) polyps.     

Prevalence of clinical and subclinical middle ear disease in cats undergoing computed tomographic scans of the head

Three hundred and ten cats that had CT imaging of the head between January 2000 and December 2007 were evaluated retrospectively. Data that were recorded included signalment, presenting complaint, clinical signs, presence of upper respiratory tract disease, and CT findings. One hundred and one cats had evidence of middle ear disease on CT. Thirty-four of the 101 cats (34%) did not have a primary complaint of ear-related disease, clinical signs or physical findings consistent with ear disease, suggesting that the middle ear disease was subclinical. Twenty-seven of the 34 cats (79%) had concurrent nasal disease. Middle ear lesions were chronic in appearance. With the exception of tympanic bulla lysis, CT findings were similar in cats presenting with primary aural disease versus cats with presumptive subclinical middle ear disease. The majority of the cats did not return for treatment of the identified middle ear abnormalities. Subclinical middle ear disease is relatively frequent in cats undergoing CT imaging of the head. Few cats required subsequent treatment for ear disease although follow up was limited. Identification of subclinical middle ear abnormalities on CT should prompt acquisition of a detailed patient history and bilateral otoscopic examination.     

Malassezia spp. overgrowth in allergic cats

A series of 18 allergic cats with multifocal Malassezia spp. overgrowth is reported: atopic dermatitis was diagnosed in 16, an adverse food reaction in another and one was euthanized 2 months after diagnosis of Malassezia overgrowth. All the cats were otherwise healthy and those tested (16 out of 18) for feline leukaemia or feline immunodeficiency virus infections were all negative. At dermatological examination, multifocal alopecia, erythema, crusting and greasy adherent brownish scales were variably distributed on all cats. Cytological examination revealed Malassezia spp. overgrowth with/without bacterial infection in facial skin (n = 11), ventral neck (n = 6), abdomen (n = 6), ear canal (n = 4), chin (n = 2), ear pinnae (n = 2), interdigital (n = 1) and claw folds skin (n = 1). Moreover, in two cats Malassezia pachydermatis was isolated in fungal cultures from lesional skin. Azoles therapy alone was prescribed in seven, azoles and antibacterial therapy in eight and azoles with both antibacterial and anti-inflammatory therapy in three of the cats. After 3-4 weeks of treatment, substantial reduction of pruritus and skin lesions was observed in all 11 cats treated with a combined therapy and in five of seven treated solely with azoles. Malassezia spp. overgrowth may represent a secondary cutaneous problem in allergic cats particularly in those presented for dermatological examination displaying greasy adherent brownish scales. The favourable response to treatment with antifungal treatments alone suggests that, as in dogs, Malassezia spp. may be partly responsible for both pruritus and cutaneous lesions in allergic cats.     

Treatment of Traumatic Separation of the Auricular and Annular Cartilages Without Ablation: Results in Five Dogs

Five dogs were diagnosed as having unilateral separation of the otic cartilages (auricular and annular). Four dogs had sustained prior trauma (hit by a car). Clinical signs were typical of ear canal stenosis and included swelling at the base of the ear (n = 2), periotic fistulation (n = 2), head tilt toward the affected side (n = 2), and pain when opening the mouth (n = 1). Palpation revealed separation of the horizontal and vertical ear canals. Otoscopic findings included a shallow ear canal and a pseudotympanic membrane across the proximal end of the auricular cartilage. Findings at surgery confirmed the diagnosis of cartilage separation and included an exudate-filled horizontal ear canal and a blind-ending vertical ear canal. Surgical treatment involved isolating the distal end of the annular cartilage (horizontal ear canal), opening and evacuating the horizontal ear canal, and suturing the open end of the annular cartilage to the skin. The length of annular cartilage was variable among the dogs, although each dog had sufficient horizontal canal to appose skin to otic epithelium. The vertical ear canal was not surgically dissected or manipulated. The mean follow-up period was 46 ± 14 months (range, 31 to 68 months). All five dogs had patent horizontal ear canals when examined at the follow-up examination.     

Fine-needle biopsy of external ear canal masses in the cat: cytologic results and histologic correlations in 27 cases

BACKGROUND: The cytologic diagnosis of ear canal tumors is difficult or impossible by swab alone because cell exfoliation may be poor and neoplastic cells may be masked by associated inflammation. Fine-needle biopsy (FNB) can be used to obtain a higher yield of cells for diagnosis. OBJECTIVE: The purpose of this study was to assess the efficacy and diagnostic value of FNB and cytologic examination in providing an accurate diagnosis of masses growing in the external ear canal of cats. METHODS: Cytologic specimens from masses in the external ear canal, taken under inhaled, general anesthesia, were classified into 4 groups: 1) ceruminous gland hyperplasia or adenoma, 2) ceruminous gland adenocarcinoma, 3) inflammatory polyps, and 4) other neoplastic and non-neoplastic masses. Cytopathologic diagnoses were compared with the final histopathologic diagnoses, and indices of diagnostic test accuracy (sensitivity, specificity, likelihood ratios, diagnostic-odds ratios) were calculated. RESULTS: Twenty-seven masses (from 25 cats, including 2 cats affected bilaterally) were included in the study. The results showed good correspondence between cytologic and histologic diagnoses with an overall agreement index (kappa) of .74, a diagnostic odds ratio of 22, and 100% (27/27) agreement in the diagnosis of inflammatory polyps versus neoplasia (both benign and malignant). CONCLUSIONS: FNB cytopathology of external ear masses in the cat was sufficiently accurate for distinguishing inflammatory polyps from neoplasia. For differentiation of benign proliferation and malignant neoplasia, however, histopathologic confirmation is recommended.     

Nasopharyngeal and Middle Ear Polypoid Masses in Five Cats

Five cats with nasopharyngeal and middle ear polypoid masses are presented. The clinical signs included nasal discharge, sneezing, labored breathing, swallowing difficulty, and voice changes. Diagnosis was made by radiography and oropharyngeal examination. Surgical mangement consisted of local nasopharyngeal polyp resection in all cats, combined with ventral bulla osteotomy in three cats. Recurrence resulted in two of the five cats in which incomplete nasopharyngeal removal was performed initially, but not in the cats treated by bulla osteotomy. Four of the five cats were clinically normal 7 to 14 (median 13) months following surgery. The fifth cat had mild upper respiratory airway noise at 7 months. The histopathologic diagnosis of these growths was inflammatory tissue.     

RADIOGRAPHIC APPEARANCE OF THE MIDDLE EAR AFTER VENTRALBULLA OSTEOTOMY IN FIVE DOGS WITH OTITIS MEDIA

Radiographs of the middle ear were made in five dogs 60 to 70 months after ventral bulla osteotomy was performed to treat otitis media. The clinical results of surgery were considered satisfactory in four dogs and unsatisfactory in one. In 4 dogs with satisfactory results, radiographs demonstratd complete reformation of the bulla in 3 operated middle ears (3 dogs), with partial bulla reformation in the three middle ears (3 dogs). Radiographs in one dog with unsatisfactory results showed complete bulla reformation with no increase in lumen opacity. The proliferative bony response obilerating the middle ear previously reported in normal dogs after ventral bulla osteotomy was not seen in any of these patients.