Laryngeal paralysis in dogs and cats (Proceedings) - Veterinary Healthcare
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Laryngeal paralysis in dogs and cats (Proceedings)


CVC IN SAN DIEGO PROCEEDINGS


Treatment

Initial management of animals with laryngeal paralysis should include symptomatic therapy to enable normal ventilation. Most animals with laryngeal paralysis are not dyspneic and may be managed conservatively by minimizing exposure to high temperature and the stress of exercise, use of a harness rather than a neck leash, and avoidance of obesity. Hyperthermia is treated by cooling the patient with wet towels or alcohol applied to the trunk and/or extremities. If the animal is dyspneic at presentation, oxygen is administered by face mask, nasal oxygen catheter, or in an oxygen cage. Corticosteroids and tranquilizers may also assist in preoperative stabilization of the patient. Rarely, temporary tracheostomy may be necessary to stabilize the animal prior to clinical work-up and definitive surgery.

Although not ideal, some dogs can be managed conservatively by owners if they keep the dog quiet and cool. These are dogs that are not overtly dyspneic on presentation. Dogs that are dypsneic need surgical intervention for relief of signs.

Surgical Treatment

Surgery is the treatment of choice for dogs with laryngeal paralysis. Laryngoplasty techniques include partial arytenoidectomy and vocal fold excision, castellated laryngofissure, and arytenoid lateralization or "tie-back" procedures. Although there is no consensus as to which surgical procedure is best most surgeons prefer to perform an arytenoid lateralization ("Tieback") technique. The goal of any surgical procedure is to widen the glottis enough to prevent dyspnea in normal semi-restricted activity. Most animals have acceptable exercise tolerance following surgery however athletic performance should not be expected. Most surgeons also agree that partial arytenoidectomy and vocal fold excision performed per os is NOT an acceptable surgical procedure. This procedure can cause "webbing" and excessive granulation tissue formation necessitating permanent tracheostomy for salvage. Castellated laryngofissure is more complicated surgical procedure that is successful in treatment of this disease. Because of the more complex nature and the fact that tracheostomy is necessary during surgery this technique is rarely performed.

Unilateral arytenoid lateralization is performed by retracting the arytenoid cartilage laterally and attaching it to the cricoid or thyroid cartilage cartilage. I prefer to suture the muscular process to the cricoid. Specifically, the muscular process of the arytenoids is sutured to the caudodorsal border of the cricoid cartilage with non-absorbable suture. Tieback procedures are performed unilaterally to decrease the incidence of aspiration pneumonia following surgery. A recent study of a large number of tieback cases revealed that about 25% of animals develop aspiration pneumonia following surgery. This may occur in the perioperative period or up to a year later. Overall success with the surgical procedure is reported to be 80-100%. Aspiration pneumonia can potentially be a serious consequence of the disease or following surgery. This risk seems to be present life-long with this disease.

Arytenoid Lateralization Procedure

     1. Place the animal in right lateral recumbency if the surgeon is right-handed. A towel is placed ventral to the neck to cause elevation of the cervical area.

     2. A 10-12 cm skin incision is made from the angle of the mandible to the jugular furrow.

     3. Subcutaneous tissue and superficial muscle is incised and the jugular vein retracted dorsally. Electrocautery is used to coagulate small bleeders.

     4. The wing of the thyroid cartilage is palpated and a "stay suture'" placed to allow lateral traction.

     5. The thyropharyngeus muscle is incised to expose pharyngeal membrane which is also incised.

     6. The cricoarytenoid articulation is palpated and separated.

     7. The cricoid cartilage on the posterior larynx is palpated and a suture of 2-0 or 0 polypropylene placed around the cricoid and then through the disarticulated muscular process.

     8. The suture is tied snugly but NOT over tightened. Remember, the animal already has an endotracheal tube in place thus the glottis is relatively open.

     9. If desired, the tube may be removed and the glottis checked for appropriate opening.

     10. The thryopharyngeus muscle and other soft tissues are closed routinely.

Postoperatively, we typically start the dog on ice-chips and then small meat balls of food to see how the animal tolerates alimentation.


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Source: CVC IN SAN DIEGO PROCEEDINGS,
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