Castellated Laryngofissure in Dogs

Castellated laryngofissure is a surgical procedure veterinary surgeons use to treat dogs with congenital or acquired laryngeal paralysis. The larynx is a collection of cartilage flaps that sit at the back of the throat over the entrance of the trachea. Muscles are attached to the larynx to allow it to open and let air pass into the lungs, but also allow it to close off the trachea when eating or drinking. If the larynx is paralyzed, the muscles keep the opening to the trachea shut and the dog cannot breathe properly. There are several surgical techniques available to correct paralysis of the larynx in dogs, one of which is castellated laryngofissure. Performed by a specialized surgeon, a castellated laryngofissure procedure entails a stepped incision into the thyroid cartilage, re-sectioning of the vocal cords and stabilization of the arytenoid cartilages. 

The clinical signs association with laryngeal paralysis suggest complications with the larynx, however, the veterinarian will want to evaluate the organ with a laryngeal examination. The motion of arytenoid cartilages will be observed during aspiration, revealing the immobilization of the vocal cords. Prior to scheduling the surgery, a radiograph of the chest will be taken to detect aspiration pneumonia, as this is a common illness paired with laryngeal paralysis. Any illness will be treated before conducting the surgery. 

On the day of the surgery, the dog will be evaluated to ensure he/she is fit to undergo surgery. The technique veterinary surgeons use to complete a castellated laryngofissure procedure entails castellating an incision through the thyroid cartilage. A step-by-step summary is describing the procedure is provided below: 

1. The canine is placed in dorsal recumbency and secured on the surgical table. 
2.  Tracheostomy tube is then placed to provide gas anesthetic and supplement oxygen. 
3. A ventral approach to the larynx will be performed as each section of thyroid cartilage is measured and divided into three separate segments. 
4. The middle segment of cartilage will be used to create a square central flap. 
5. Cautery marks the castellated line on the ventral aspect of the thyroid cartilage. 
6. The thyroid is then incised along the castellated line using a number 11 scalpel blade. The veterinarian will use this same blade to incise the cricothyroid membrane. 
7. Both vocal cords are removed.
8. The laryngeal mucosa is sutured. 
9. The central flap of cartilage is moved cranially, aligning with the opposite cranial thyroid segment. The vet maintains this central flap by suturing the cartilage in place with non-absorbable material.  
10.  As closure of the laryngeal mucosa is not attempted over the defect, the sternohyoid muscles are positioned over the defect and sutured in place. 
11.  Routine closure of the tissue and skin. 

The efficacy of a castellated laryngofissure procedure in dogs is variable. Some veterinarians prefer other surgical options to correct a dog with laryngeal paralysis, but castellated laryngofissure technique has proven to be effective. The choice is often determined by the size of the dog, severity of the condition, and the personal preference of the surgeon. 

Following a castellated laryngofissure surgery, a temporary tracheostomy tube will remain in the patient for three to four days post operatively. Patients will not be allowed to eat or drink for 24 hours unless otherwise directed by the veterinarian. Sedatives and heavy analgesics will be administered on a routine basis in order to maintain the dog’s swallowing reflex without pain. Hand feeding the canine small amounts of soft food will be carried out by the dog owner at home and continue for up to two weeks after surgery. Dogs should not use neck collars. Physical activities will be limited as the dog rests and recovers for the next four to six weeks. 

The average cost to have a castellated laryngofissure surgery performed on a dog is roughly $2,000 to $3,000. The cost of the surgery depends on the severity of the dog’s condition and aftercare.

Following a castellated laryngofissure surgery, a temporary tracheostomy tube will remain in the patient for three to four days post operatively. That being said, the patient will require at least a week in the hospital before returning home, which can be costly. The effectiveness of this surgery is debatable. 

Most forms of laryngeal paralysis are hereditary and occur for unknown reasons, therefore, prevention is unobtainable. Trauma to the throat, head and chest can cause this condition in other canines, so take the appropriate canine safety measures to prevent the need for castellated laryngofissure surgery.