Total Ear Canal Ablation and Bulla Osteotomy
Diseases of the external ear canal are common in dogs. Certain breeds (such as Cocker spaniels) have a higher incidence of severe disease. Despite the best efforts by primary care veterinarians to control these diseases, some dogs progress to an unrelenting stage of pain, odor, and decreased quality of life. Dogs that have reached an end-stage of disease (that is, have become refractory to all medical treatment) can be helped substantially by surgery. There are a number of surgeries available for assisting in the medical management of chronic ear disease, including the lateral ear canal resection (also called a Zepp or Lacroix-Zepp procedure), whereby the outer wall of the external ear canal is permanently flapped downward to create a larger, deeper opening into the ear canal.
However, dogs that have reached an end-stage of otitis externa, and especially those breeds where progression is almost certain despite stop-gap procedures such as lateral ear canal resection, are better served by total ear canal ablation (TECA). We define TECA as a “salvage surgery”, which means the ear canal cannot be saved, and this surgery should permanently relieve the clinical signs associated with the chronic disease. Ablation means complete removal. In TECA surgery the entire ear canal is removed, from the base of the pinna (ear flap) to where the ear canal enters the middle ear cavity at the base of the skull. Because infection has usually caused rupture of the tympanum (eardrum), and extended into the middle ear cavity, TECA is usually accompanied by surgery to remove any disease from the middle ear cavity as well. The bony cavity of the middle ear is called the tympanic bulla, and so a bulla osteotomy (enlarging the opening into the middle ear cavity) is typically performed in conjunction with the TECA. For shorthand, we term the combined operation “TECA-(L) BO” (the “L” refers to lateral, or outer wall, osteotomy of the bulla).
Besides chronic infection, the other major indicator for TECA surgery is for cancerous growths in the ear canal. This can occur in any breed, and is also the most common indication for TECA surgery in cats.
Common questions and potential complications associated with TECA-LBO:
- Will you need to cut my dog’s ear(s) off? No! The pinna, or ear flap, is NOT removed when we ablate the ear canal. However, animals with erect ears may have a less erect ear after surgery.
- What medical therapy will my dog’s ear(s) need after surgery? Will I still need to clean the ears and place medicine in them? Since we are removing the entire ear canal, we close up the skin where the opening to the ear canal used to be. There is no longer a hole there, and therefore no need to treat! This generally makes patients and owners much happier than they were prior to TECA surgery. Some dogs do still have allergic or other skin problems that affect the pinna, so treatment for that might continue if needed.
- Will my dog be deaf? Most dogs that are candidates for TECA surgery in the first place have already had such chronic damage to their ear canals and eardrums that they suffer diminished hearing acuity well before any surgery. Removal of the ear canals in these patients, even bilaterally, does not usually result in a noticeable worsening in most instances. Most dogs can still conduct some sound to the inner ear by transmission of sound waves/vibration through the bone adjacent to the inner ear. And even when dogs do seem to hear less well after surgery than they did before surgery, this does not adversely affect their quality of life. In some cases, clients are happier, since the dog no longer becomes agitated by thunderstorms and firecrackers!
- What are the side-effects or complications of TECA surgery? There are several potential complications that can occur, some in the short-term and some long-term. The deepest aspect of the ear canal lies in an area where there are major blood vessels and branches of the 7th cranial nerve (facial nerve). During surgery it is possible to injure these structures, especially since dogs with chronic ear canal disease often have mineralization and scarring of the ear canals that can entrap the nerve branches. Every effort is made by the surgeon to identify these nerves and vessels, and to protect them from injury during the TECA operation. However, intra-operative hemorrhage can occur if a blood vessel is damaged. This can be severe enough to require a blood transfusion, and could potentially be fatal, but in most cases, even when it occurs, it is managed without extraordinary means. More common is injury to the facial nerve. In published studies this is reported to occur in about 30% of TECA operations, so it is a common complication. The result of facial nerve injury is decreased or absent ability to blink the eyelid on that side, and some droop to the upper lip on that side. In most cases this nerve deficit (analogous to Bell’s palsy in people) is transient. But even in dogs where the problem is permanent, it does not cause pain, and usually requires no extra care or treatment. Dogs have a third eyelid (nictitating membrane) in the inner corner of their eye that helps protect the cornea and spread the tear film over the eye. So, unless the dog has a missing third eyelid or produces insufficient amounts of tears, the eye is well protected even though the outer lids aren’t blinking. The droopy lip may make the dog a bit sloppier when drinking and eating, but not usually to any severe degree. A far less common short-term complication is a balance problem owing to inflammation of the inner ear. It is actually much more common to see this type of vestibular problem occur spontaneously in dogs with chronic ear disease than it is as a consequence of TECA surgery.
Potential long-term complications, besides the diminished hearing acuity in dogs with bilateral TECA, include late infection of the surgery site. Even though every effort is made to remove all diseased tissue during the operation, it is possible that a tiny nidus of infection may be left behind. There are lots of “nooks and crannies” where bacteria can hide, and we have to remember that the germs in these dogs have been bombarded – often for years prior to TECA surgery – with antibiotics of various sorts. So they are often very antibiotic-resistant strains. Therefore, these small clusters of resistant bacteria may find a place to hide despite surgery and flushing, and then fester. Eventually this festering process could result in an area of swelling and tenderness under the skin where surgery was performed. When this uncommon complication occurs it can often be treated with topical compressing and antibiotics. But if it continues or recurs, additional surgery may be needed to explore for and remove any residual diseased tissue, and to place drain tubes for a short duration. Regardless, even in those few dogs that have a late infection, and even those that require an additional surgical procedure, most clients will report that the dog’s and their quality of life is still far superior to what it had been when they were trying to medically manage the dog’s ear canal disease.