Balloon dilation for the treatment of nasopharyngeal stenosis in seven cats

Clinical and computed tomography findings in cats with nasopharyngeal stenosis

OBJECTIVES

Concurrent anomalies are often found in nasopharyngeal stenosis and choanal atresia; some seem to be of primary nature, whereas others may be coincidental. This study aimed to report the computed tomography features and related comorbidities of these diseases.

MATERIALS AND METHODS

A cross-sectional retrospective study was performed using case and control groups defined according to the presence of signs of upper airway disease and the presence/absence of nasopharyngeal stenosis, respectively. The inclusion criteria were full-head tomography scans and access to clinical records. The exclusion criteria were brachycephalic breed, head trauma and neoplasm. Clinical and computed tomographic findings and relevant comorbidities were recorded.

RESULTS

Forty-three cats were included, 23 cases and 20 controls. The case group was significantly younger, had more paranasal sinus anomalies and never had turbinate lysis, also, had significantly more soft palate anomalies, which was significantly shorter. Nasopharyngeal stenosis varied from membrane appearance to partial or complete adhesion of the soft palate to the nasopharynx, was mainly located in the caudal region of the nasopharynx and was imperforated in approximately half of the cases. Imperforated membranes were significantly thicker in the sagittal plane and were significantly associated with nasal obstruction and soft tissue attenuation of the tympanic bulla. Hiatal hernia and ventricular asymmetry were only encountered in three and two cases, respectively, with nasopharyngeal stenosis.

CLINICAL SIGNIFICANCE

Computed tomography in cats with nasopharyngeal stenosis can identify concurrent anomalies, can help to differentiate a possible choanal atresia and evaluate the magnitude of its significance.

A case of epiglottic entrapment in a cat

OBJECTIVE

The objective of this study was to describe a case of epiglottic entrapment in a cat.

CASE SUMMARY

A 5-month-old male neutered Russian Blue cat was evaluated for progressive stertorous upper airway sounds, acute onset vestibulopathy and abnormal laryngeal anatomy. Endotracheal intubation was only able to be achieved using videoscopic guidance and identified concern for severe nasopharyngeal stenosis. A computerized tomography scan revealed otitis interna, narrowed nasopharynx and no definitive cause for the stertorous breathing. The cat recovered very slowly from anaesthesia due to concern for airway obstruction following extubation. It was discharged the following day and then passed away at home 2 weeks later. Necropsy revealed that the epiglottis was obscured by 2 cm of redundant mucosal tissue extending from the base of the tongue to the larynx resulting in epiglottic entrapment. Also noted was chronic, severe otitis interna and externa. Upper airway obstruction is suspected to be the cause of sudden death.

NEW OR UNIQUE INFORMATION

To the authors' knowledge, this is the first report of these oropharyngeal anatomic abnormalities in a cat.

Treatment of acute traumatic nasopharyngeal stenosis with balloon dilation in two dogs

CASE HISTORY

Two dogs were referred to Veterinary Specialists Aotearoa for evaluation and treatment after sustaining significant head trauma. Case 1 was a 7-month-old, female Staffordshire Bull Terrier who was hit by a car at low speed. Case 2 was a 2-year old, male neutered German Shepherd who sustained a gunshot wound to the head whilst on duty for the New Zealand Police Dog Unit.

CLINICAL FINDINGS

The dog in Case 1 suffered numerous facial fractures which caused collapse of the ventral nasal meatus and dorsal nasopharyngeal wall. The dog in Case 2 had extensive osseous and soft tissue damage to the nose, nasopharynx and cervical region with severe narrowing of the ventral meatuses, nasopharyngeal meatus and rostral nasopharynx due to multiple fracture fragments and shrapnel pieces. A diagnosis of traumatic nasopharyngeal stenosis was made in each case by computed tomography. Mechanical balloon dilation was used to treat the stenosis in both dogs. The balloon dilations were performed using a 12-mm balloon dilation catheter inserted in an antegrade fashion. In the first dog, the procedure was performed blind and was repeated three times with 5 and 9-day intervals between dilations. In the second dog, the procedure was performed under endoscopic guidance and again, was repeated three times with a 7-day interval between dilations. Clinical success was reported in both patients following treatment and the second dog also underwent a follow-up computed tomography scan which confirmed resolution of the stenosis.

DIAGNOSIS

Traumatic nasopharyngeal stenosis that was successfully treated with balloon dilation.

CLINICAL RELEVANCE

Findings suggest that balloon dilation may be an effective technique for the treatment of traumatic nasopharyngeal stenosis in dogs. Multiple dilation procedures are likely required, but the procedure can ultimately result in long term clinical resolution.