Stephen J. Birchard DVM, MS, Diplomate ACVS

Monday, July 14, 2014

Surgical Correction of Enlongated Soft Palate in Dogs: Helping brachycephalics breathe.

The soft palate (SP) in the dog forms the partition between the oral and nasopharynx. The cranial border of the SP is attached to the hard palate, and the caudal border extends to the tip of the epiglottis.  Elongated soft palate is one aspect of brachycephalic syndrome and is common in dogs such as English bulldogs, pugs, and Boston terriers. The soft palate is considered elongated if it extends caudally beyond the articulation with the epiglottis. (Fig. 1) 
Fig. 1: Elongated soft palate in a bulldog. (the dog is in ventral recumbency).
Note the tonsils on each side of the palate.
It causes obstruction of the glottis and stertorous breathing which can be a significant respiratory problem in affected dogs. Concomitant stenotic nares worsen the condition by increasing inspiratory effort and causing further extension of the SP into the airway. (see blog on stenotic nares, May 10, 2014)

After obtaining a thorough history and performing a physical examination, take thoracic radiographs to rule out hypoplastic trachea and complications of upper airway obstruction such as pneumonia or pulmonary edema.

Surgical Procedure

A variety of surgical techniques have been described for correction of elongated SP.  The basic objective of surgery is to remove the portion of SP that is causing airway obstruction.  The amount of tissue to be resected is determined by either measuring the portion of SP that extends beyond the tip of the epiglottis, or by removing the portion of SP that extends beyond the caudal pole of the tonsils. (Fig. 2)  
Fig. 2: Incision line for removal of the excess soft palate.
The line connects the caudal pole of the tonsils.
Resection of too much tissue can result in nasal regurgitation of food and water with resultant aspiration pneumonia.

Since hemorrhage is a potential complication of resection, some authors recommend placing a clamp across the area to be removed, removing tissue using electrocautery, or injecting the tissue with epinephrine.  The author does not recommend these techniques since they encourage tissue edema that can be a life-threatening post-operative complication. Surgical laser and the Ligasure device have also been used for soft palate resection.  An atraumatic “cut and sew” technique described many years ago has been very successful in the author's experience and remains my procedure of choice.(1)

Place the animal in ventral recumbency with the head at the end of the table and the mouth held open with an oral speculum. (Fig. 3)  
Fig. 3: Patient positioning for soft palate surgery
Be sure that the endotracheal tube has a competent cuff that is appropriately inflated to prevent aspiration of blood during the procedure. Administer intravenous dexamethasone (0.1 mg/kg) to help control tissue edema secondary to surgical manipulation. Briefly remove the endotracheal tube to examine the soft palate and compare its length to the epiglottis. Replace the tube and secure it in place. Grasp the middle of the SP with an Allis tissue forceps and place stay sutures (4-0 PDS or Monocryl, taper needle) at the lateral aspects of the SP where the incision will be made. (Fig. 4)  
Fig. 4: Stay sutures have been place at the proposed site of incision (dotted line)
From: Bright RM, Wheaton LG (1983) A modified surgical technique for elongated soft palate.
J Am An Hosp Assoc 19: 288-92
Sharply incise the soft palate with long-handled curved Metzenbaum scissors. (Fig. 5)  
Fig. 5: Angled Metzenbaum scissors (above) are useful for incision of the soft palate.
Conventional scissors are shown below.
Incise half way across the palate; the mucosa of this cut portion is then sutured with the long end of the stay suture in a simple continuous pattern. (Fig. 6) 
Fig. 6: The soft palate has been partially incised and suture closure begun.
From: Bright RM, Wheaton LG (1983) A modified surgical technique for elongated soft palate.
 J Am An Hosp Assoc 19: 288-92
Then incise across the remaining palate and suture the mucosa in a similar fashion. (Fig. 7)
Fig.7: Completed excision and closure of the soft palate.
From: Bright RM, Wheaton LG (1983) A modified surgical technique for elongated soft palate.
J Am An Hosp Assoc 19: 288-92
Hemorrhage is usually not a significant problem once the incisions are closed.  The trachea is gently suctioned if hemorrhage was excessive. To check the soft palate for adequate resection of tissue, briefly remove the endotracheal tube to allow comparing the soft palate length to the epiglottis, then replace the tube for the remainder of the dog's recovery from anesthesia.

Postoperative Care
Post-operatively, leave the endotracheal tube in place as long as possible until the animal is fully awake.  The animal should recover in a cool environment and be observed closely for evidence of airway obstruction due to tissue edema.  Keeping the chin elevated seems to help brachycephalic dogs move air during anesthesia recovery. The intravenous steroids can be repeated if edema is suspected. Tramadol is administered for 5 days for analgesia.

Although most dogs recover without incident after soft palate resection, if complications occur they can be life threatening. Therefore recovery from surgery should be in a hospital that has 24 hour care at least for the first night after the procedure. Results of surgery are usually very good; some inspiratory noise may remain but respiratory function should be improved. One study found a good to excellent outcome in 34 dogs with long-term follow up after surgery for brachycephalic syndrome.(2)

1. Bright RM, Wheaton LG. A modified surgical technique for elongated soft palate. J Am An Hosp Assoc. 1983; (19): 288-92.
Riecks TW, Birchard SJ, Stephens JA. J Am Vet Med Assoc. 2007;230(9):1324-8.

No comments:

Post a Comment