Your 4 pearls for oronasal fistula repair in dogs and cats

An oronasal fistula is an opening, known as a communication, between the oral and nasal cavity. This can lead to chronic rhinitis, nasal infections, sneezing, bad breath, and nasal discharge. Oronasal fistulas are most commonly a result of periodontal disease.¹

“For me, when I extract a canine tooth—no matter what degree of periodontal disease, even if I remove it with my fingers—I always assume I have oronasal fistula that I’m going to fix,” noted Mark Smith, VMD, DACVS, DAVDC of the Center for Veterinary Dentistry and Oral Surgery in Gaithersburg, Maryland. According to Smith, acute oronasal fistula normally occurs following canine tooth extraction or extraction of teeth with severe periodontal disease, leading to direct communication with the nasal cavity.

During his presentation at New York Vet 2021, he offered up a few pearls of wisdom on this topic.

1. The single flap technique is all you need

Smith said that acquired palatal defects are typically repaired with a single layer transposition flap. However, a double flap technique may be needed for the revision of failed single-flap procedures. Smith recommended mastering the single flap technique.

He said that he “hardly ever” uses a double flap technique, in cases where another surgeon has operated on the fistula and failed, and he needs to “guarantee” that the repair is going to work. He asserted: “The single flap technique should work all the time. That’s all you need to know how to do. If you know how to do this, you should be good.”

2. Palatal defects can be congenital

Smith further discussed congenital palatal defects, which he states are more common in brachycephalic and purebred dogs. These patients may have a number of issues, including difficulty nursing, rhinitis, nasal discharge, and aspiration pneumonia. He advised: “Upon diagnosis, puppies and kittens should receive a thorough examination and workup to determine the presence of other congenital defects. It is recommended that patients be managed by tube feeding only until old enough to safely be administered general anesthesia.”

3. The bipedicle flap technique has 2 disadvantages

According to Smith, the bipedicle flap is 1 of the 2 most common repair techniques for congenital hard palate defects. However, it may come with downsides. He explains, “The primary disadvantages of this technique include wound closure unsupported by bone, and the subsequent potential exposure of the nasal cavity on the lateral aspect(s).”

Smith says the potential exposure of the nasal cavity can consequently be repaired from 2 to 3 weeks after the initial procedure and usually can be done using the single flap technique. Conversely, Smith states the overlapping flap technique has the advantage of flap support by underlying bone and the avoidance of lateral defects after midline repositioning.

4. “Tension is the killer…”

When performing these procedures, Smith stressed the importance of avoiding tension on the flap. He told attendees: “The surgical principles are simple, no tension on your flap. You’ve heard that time and time again from surgeons. Tension is a killer, because tension often leads to dehiscence, and that’s the main cause of dehiscence. It’s not infection; it’s tension.”

Reference:

Oronasal Fistulas. Veterinary Dental Center. Accessed November 3, 2021. https://www.veterinarydentalcenter.com/oral-conditions/infection-inflammation/oronasal-fistula/