Ventral Bulla Osteotomy in Cats

The bulla is the middle ear cavity. When this cavity becomes severely infected, or when a foreign item, polyp, or tumor is located in it, severe discomfort can result for a cat. The cat will likely begin to scratch at its ears, circle, or tilt its head. Discharge may drain from the ear and if a large enough growth is present, the cat may begin to experience difficulty breathing. 

When all these signs are present, blood tests will be run to diagnose the issue. In most cases, the eardrum will first be flushed in an attempt to clean out the cavity. If symptoms persist, the middle ear will have to be surgically opened in a process called a “ventral bulla osteotomy’. Once the bulla has been opened, infected tissue, polyps, tumors or foreign bodies will be removed. This surgery is very complicated and should only be performed by an ACVS board-certified veterinary surgeon. 

Blood work will need to be run, both to confirm the cat's condition and to establish whether it will be a good candidate for general anesthesia or not. X-rays of the middle ear cavity will be taken to locate infected tissue or growths. If possible, a CT scan should be used, as it will offer far more detail for surgical planning. Biopsy of any growths may need to be taken and evaluated at a lab. 

If surgery is deemed necessary, a date for the procedure will be booked. To begin the operation, an incision will be made behind the jaw, under the neck. The pterygoid muscle will be separated with a scalpel so that the bulla is accessible. The bulla will then be opened and inspected. If polyps, tumors or foreign bodies are present, they will be removed at this time. If only infection is present, the lining of the bulla will be removed. The cavity will then be flushed with saline solution to clean out all other materials. A suture is then placed in the cat's septum. The septum will then removed along with the wall of the bulla. A tube will be added to the middle ear cavity to allow it to drain for several days post-surgery. The neck incision will then be sutured shut.

Although complex, this surgery carries a fairly good prognosis for the cat, with 80% of animals being cured after receiving the treatment. The same percentage of cats will go on to develop a short-lived case of Horner's Syndrome, which will generally clear up on its own. In some instances, the polyp may be plucked out of the bulla manually. There are risks associated with this, with only 50% of these removals being successful. This is due to the likelihood of the polyp base remaining in the bulla and regrowing in the cavity.

The cat should be monitored as it comes off of the anesthesia to ensure that no complications arise. A drain will be used for several days to eliminate the contents of the bulla. It will then be removed by the veterinary surgeon. The wound will be bandaged during this time. An Elizabethan collar will be needed to prevent the cat from scratching at its ears and neck during recovery. To get the cat to resume eating, it may need to be coaxed using warm, aromatic foods. A course of antibiotics will likely be prescribed, especially if an infection was present in the animal. This prescription may last as long as five weeks. 

As this procedure is complicated and involves the use of high-tech veterinary equipment, it often ranges in cost from $2,000 to $4,000. A highly skilled veterinary surgeon is needed, and they often charge higher prices for their expertise. If CT scans or biopsies are needed, these will further increase the price. Any medications used will also cause the total cost to go up. 

Complications after this procedure are rare, but do happen. Reactions from the general anesthesia can be life-threatening. In some cases, polyps or tumors may continue to grow after being removed. Further infection may develop in the animal. Facial nerve paralysis is possible, but very unlikely. Horner's Syndrome develops in many cats after receiving a ventral bulla osteotomy but is generally mild and resolves on its own within a month or so. The overall prognosis for this procedure is usually very good and few long-term risks are associated with it. 

It is hard to prevent the development of infections, inflammatory polyps or cancer, but certain precautions can be taken. There has been a link found between upper respiratory infections and polyp development, so getting prompt treatment may help fix the issue before polyps are present. Feline leukemia virus and feline immunodeficiency virus have also been connected to inflammatory polyps, so vaccinating your cat and keeping it indoors, away from any infected cats can help prevent these incurable diseases from spreading. 

Polyps are generally found in younger cats, while cancerous tumors are more common in older cats. Many cancers may be genetic, but limiting exposure to known cancer-causing carcinogens and toxins such as cigarette smoke or car exhaust may help delay cancer growth.  Take your cat in for treatment as soon as signs of an ear infection are seen.