Author

Stephen J. Birchard DVM, MS, Diplomate ACVS

Friday, December 19, 2014

Permanent Tracheostomy in Dogs: A life-saving surgical option for severe upper airway obstruction.

Permanent tracheostomy is a well-recognized surgical technique used in animals and humans as a salvage procedure to treat severe upper airway obstruction. Although the technique has been used for many years with success, there are many misconceptions among animal owners and veterinarians about the long-term care and complications. Many feel that dogs cannot have a good quality of life because of the problems associated with tracheostomy. Owners frequently expect that dogs with permanent tracheostomy will have an appliance, i.e. a metal or plastic tube that resides with in the trachea and needs constant care.

Indications for tracheostomy in dogs include: severe laryngeal obstruction due to laryngeal paralysis, collapse, neoplasia, or trauma, pharyngeal neoplasia that obstructs the larynx, and non-resectable proximal tracheal neoplasia.

Although cats may also develop disorders causing severe upper airway obstruction, permanent tracheostomy is associated with frequent, severe complications such as excessive mucous production and stoma stricture.(1) As a result, tracheostomy is rarely recommended in cats.

Preoperative Considerations

Dogs being considered for tracheostomy should be thoroughly evaluated with particular emphasis on the respiratory tract.  A complete history and physical examination followed by appropriate imaging such as thoracic radiographs are important before performing general anesthesia and surgery. Cervical radiographs and even tracheoscopy may be necessary to be certain that the respiratory tract downstream from the larynx is normal. Also, carefully examine the dogs’ ventral cervical area to determine suitability for creating a tracheostomy stoma. Some dogs, such as brachycephalic breeds, have very short necks with excessive skin that can cause problems with skin flaping over the stoma causing obstruction.

Surgical Technique

The dog is placed in ventral recumbency with the neck hyperextended over a soft towel and the front legs extended caudally. The ventral cervical area is clipped and prepared for aseptic surgery. A ventral midline skin incision is made from the larynx to just cranial to the manubrium.  The paired sternohyoideus muscles are divided on their midline using sharp dissection. A large horizontal mattress suture of 2-0 or 3-0 PDS is placed across the sternohyoideus muscles, dorsal to the trachea, to allow retraction of the muscles and cause ventral displacement of the trachea.(Fig. 1) 
Fig. 1: Ventral midline cervical approach for permanent tracheostomy.
The sternohyoideus muscles have been divided and a horizontal mattress suture
is being placed in the muscles to tuck the muscle under the trachea.
Care is taken to avoid trauma to the recurrent laryngeal nerves during passage of the suture. A rectangular window is created in the trachea from the 3rd to the 7th ring (4 rings included in the tracheal opening).(Fig. 2) 
Fig. 2: The rectangular window is being created in the tracheal wall.
Note the endotracheal tube present in the tracheal lumen.
The tracheal incisions are begun by incising between rings 3 and 4, then between rings 7 and 8. Be careful not to puncture the cuff of the endotracheal tube when making the initial tracheal incisions. These parallel incisions are then connected using scissors to complete the rectangular shaped defect in the trachea.(Fig. 2)

Close the tracheal wall to the skin in a simple interrupted pattern to create the tracheostomy stoma. Excise a rectangular shaped section of skin on each side of the tracheostomy site to allow the skin incsion to match the rectangular window in the trachea. The suture bites of trachea include the cartilage, and the bites of the skin are placed split thickness, entering the dermal layer and exiting the epidermis.  This allows for accurate apposition of the epidermis to the tracheal mucosa. As in urethrostomy closure, take suture bites from inside out, i.e., start in the tracheal lumen and then take the bite of the skin. The corners of the window are closed first (Fig. 3,4); then the remaining areas are closed in a similar fashion.(Fig. 5) Absorbable suture such as 3-0 or 4-0 PDS is used to avoid having to remove them once the stoma has healed. The skin incisions cranial and caudal to the stoma are then closed routinely.
Fig. 3: The 4 corners of the rectangular tracheal window are closed first.
Note the "inside-out" sequence of suture placement.
Fig. 4: The corner sutures have been placed.

Fig. 6: Completed suture closure of the tracheal stoma. 
Postoperative Care

Alleviation of inspiratory dyspnea is immediate after permanent tracheostomy. See below video of an elderly labrador with laryngeal paralysis before and after permanent tracheostomy. Although laryngeal tie-back is the treatment of choice for most dogs with laryngeal paralysis, permanent tracheostomy was chosen in this dog due to high risk for aspiration pneumonia.
Besides routine postoperative care such as analgesics, cleansing of the stoma is important to prevent build up of discharge and debris. (Fig. 6) Gently wiping the skin around the stoma with moistened gauze sponges is sufficient.


Fig. 6: Typical appearance of a recently preformed permanent tracheostomy
in a Yorkshire Terrier with severe laryngeal collapse.
Owners should be advised to avoid putting anything inside of the trachea and to not use any irritating materials around the stoma such as peroxide or other antiseptics. Small amounts of a petroleum-based ointment (e.g., triple antibiotic ointment) can be placed on the skin around the stoma to prevent discharge from adhering to the skin and make cleaning easier. Discharge from the tracheal stoma tends to gradually decrease over the first few weeks postoperatively. Systemic antibiotics are not routinely prescribed since incisional infections are very rare.

Life Style Limitations
Dogs with a permanent tracheostomy cannot go swimming and should avoid very dusty environments or running in tall grass or weeds. These dogs will also will have difficulty barking or at least have a softer sound than pre-operatively. In rare cases dogs with long hair will need clipping of the hair around the stoma to prevent irritation of the tracheal mucosa and accumulation of debris.

Prognosis

Most dogs with permanent tracheostomy do well and have minimal chronic problems. The most common long-term postoperative problems are pneumonia and stricture of the stoma requiring surgical revision.(2) In a recent study sudden death occurred after tracheostomy in 5 of 19 dogs at variable times after surgery, presumably due to obstruction of the trachea although necropsy was not performed in any of the cases.(2)

Permanent tracheostomy is considered an appropriate surgical option for dogs with severe upper airway obstruction. Complications can occur but some, like stoma stricture and skin fold occlusion, can be treated by revision surgery. Owner education is important to explain potential risks and life style limitations.

References

1. Stepnik MW1, Mehl ML, Hardie EM et. al. Outcome of permanent tracheostomy for treatment of upper airway obstruction in cats: 21 cases (1990-2007). J Am Vet Med Assoc. 2009 Mar 1;234(5):638-43.


2. Lindsay L. Occhipinti and Joe G. Hauptman. Long-term outcome of permanent tracheostomies in dogs: 21 cases (2000–2012) Can Vet J. Apr 2014; 55(4): 357–360.

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