Cricopharyngeal Myotomy and Myectomy in Cats

Cricopharyngeal myotomy and myectomy are surgical procedures commonly used to treat cricopharyngeal dysphagia, a condition that is characterized by difficulty swallowing, that does not respond to medical treatment. Dysphagia may occur as a primary or secondary condition. If dysphagia is secondary to another condition, the other condition must be treated as well. For these cases, the success of cricopharyngeal myotomy and myectomy may be limited. Cats that have secondary dysphagia benefit less from surgery than those with primary cricopharyngeal dysphagia.

Cricopharyngeal myotomy and myectomy are often performed together. Cricopharyngeal myotomy refers to the process of incising the cricopharyngeal muscle. Cricopharyngeal myectomy involves removing a small portion of this muscle. The general procedure steps are outlined below.

1. The cat will be anesthetized and prepped for surgery. The underside of the jaw and neck will be shaved, and a sterile drape will be placed. The head may be secured to the operating table.
2. The surgeon will make the initial incision into the skin.
3. The sternohyoidus muscles will be separated, and the larynx and trachea are retracted and held in place using stay sutures so that the cricopharyngeal muscle can be visualized.
4. The cricopharyngeal muscle will be incised. The muscle will then be elevated, and its fibers incised. (This comprises myotomy.)
5. During this time, the thyropharyngeus muscle may also be incised, particularly if achalasia is present.
6. A small portion of the cricopharyngeal muscle, no larger than 1 cm, will then be removed.
7. The surgery site will then be lavaged, or flushed, thoroughly with a saline solution.
8. The sternohyoidus muscles are then sutured before the skin incision is also sutured.
9. Cats that have concurrent aspiration pneumonia may be hospitalized following surgery and given supportive care.

Cricopharyngeal myotomy and myectomy are considered effective treatments for cricopharyngeal dysphagia and achalasia. Surgery typically resolves the inability to swallow. Additional treatments may be required to treat the underlying condition responsible for cricopharyngeal dysphagia. The success rate of cricopharyngeal myotomy and myectomy is approximately 65%. Animals that are diagnosed with underlying neurological disorders are less likely to benefit from surgery. However, the difficulty swallowing has a better chance of resolving if the underlying condition is identified and treated. Cats that have aspiration pneumonia have a more guarded prognosis.

For the first forty-eight hours following surgery, cats should eat soft or blended foods. Cats may return to their normal diet gradually over the course of three weeks following surgery or as instructed by the surgeon. If the condition persists after surgery, this is a sign that the surgery was unsuccessful, the diagnosis was wrong, or that the procedure was incomplete. Achalasia typically resolves immediately following surgery. 

The cost of cricopharyngeal myotomy and myectomy will vary based on standards of living and additional costs incurred. The cost of cricopharyngeal myotomy and myectomy is approximately $1,800.

Cricopharyngeal myotomy and myectomy are expensive, complex procedures and are not typically the first line of treatment for cricopharyngeal dysphagia. The veterinarian will first attempt to treat this condition using conservative methods, most commonly medication. Chronic cricopharyngeal dysphagia may be treated with cricopharyngeal myotomy and myectomy. Cricopharyngeal achalasia must be treated surgically.

This procedure should not be performed in cats that have pharyngeal dysphagia as opposed to cricopharyngeal dysphagia as this may lead to worsening of symptoms and possibly aspiration pneumonia.

Complications of cricopharyngeal myotomy and myectomy include, but may not be limited to:

• Damage to the oesophageal wall
• Recurrence of the condition
• Laryngeal paralysis: Abnormal function of the laryngeal muscles, which control breathing
• Fibrosis
• Pharyngocutaneous fistulation/infection: A passage in the pharynx through which saliva leaks.
• Aspiration pneumonia

The most common complication of cricopharyngeal myotomy and myectomy is aspiration pneumonia. Laryngeal paralysis and pharyngocutaneous fistulation will require additional surgery to correct. Infection is not very common with this procedure.

Some causes of cricopharyngeal dysphagia cannot be prevented, particularly those that are attributed to congenital defects. Owners should make sure their cats stay up-to-date on vaccinations against neurological disorders, particularly rabies. Exposure to wild animals that are possible carriers of rabies should be avoided. Cats that experience cricopharyngeal dysphagia due to congenital defect should not be bred.