A Young Cat with Nasopharyngeal Stenosis

A 1-year old spayed female domestic shorthair cat was evaluated for an 8-month history of increased respiratory and nasal noise which was partially responsive to several courses of antibiotic therapy.  Her signs would improve while on a course of antimicrobials, then recur within a week of cessation of treatment.

Physical examination was normal aside from purulent nasal discharge from her right nostril and increased inspiratory upper airway noise referred upon thoracic auscultation.

CT examination was performed, and a longitudinal section at the level of the mid-skull is shown below.   Describe the pathology seen on CT.

Retroflexed rhinoscopy was performed.  In the image below, the soft palate is on the left side of the image and the dorsal aspect of the oropharynx is on the right side of image.  Describe the pathology seen on retroflexed rhinoscopy.

A 5 French red rubber catheter was passed through the nostril, but could not be advanced through the nasopharynx, which is shown below.

Based on the CT and retroflexed rhinoscopy findings, what is the diagnosis for this patient?

What are the treatment options for this patient?

The red rubber catheter was removed from the patient’s nasal passage and the closed tip was cut.  The catheter was replaced into the nasal passage and advanced as far caudally as possible, as seen in the previous image.  The stiff end of a 0.025” hydrophilic guidewire was passed through the cut red rubber catheter and used to puncture the strictured nasopharyngeal tissue under retroflexed rhinoscopic visualization. Once through the wire punctured the tissue, the wire was withdrawn, and the flexible end of the hydrophilic guidewire advanced through the cut red rubber catheter and through the punctured nasopharyngeal tissue.  The wire was manually grasped and pulled out of the oral cavity, as shown below.

The stenosis was dilated progressively using 6mm, 8mm and 10mm balloon dilation catheters over the wire spanning the oral cavity, nasopharyngeal stenosis and nasal cavity.  Each size balloon was kept expanded for 90 seconds as shown below.  The progressive stenosis dilation pictures are shown below.

Are there other techniques that can be used to dilate the nasopharyngeal stenosis?

Are there additional therapies that can de done at the time of dilation?  What is the evidence for the use of this treatment?

What is the evidence of use steroids in patients with nasopharyngeal stenosis?

How many patients need additional dilation procedures?  How many are generally needed?

Two weeks after the initial balloon dilation, the patient’s clinical signs recurred. Repeat retroflexed rhinoscopy of the patient’s nasopharynx is show below.

The procedure was repeated with 6mm, 8mm, 10mm, and 12mm balloon dilation catheters.  After dilation, the following image was obtained.

 

Since the stenosis was significantly dilated compared to the start of the procedure, the flexible scope was able to be advanced above the palate, and the choana were seen, as shown below.

Mitomycin was infused onto the dilated tissue via the red rubber catheter after packing the oropharynx with gauze to collect any excess mitomycin.

The patient was evaluated one month later, during which time the cat was doing clinically at home.  Repeat retroflexed rhinoscopy revealed the following image.  Since the patient was doing well clinically, and the area had not restructured, a repeat balloon dilation was not performed.

If the area re-strictures after several dilation procedures, what are the management options for the patient?

Category: Cases, Endoscopy, Head and Neck, Respiratory