Balloon-Expandable Metallic Stent Placement for Benign Nasopharyngeal Stenosis in 4 Dogs and 3 Cats
Matthew J. Ryan Veterinary Hospital of the University of Pennsylvania
Philadelphia, PA, USA
Nasopharyngeal stenosis (NPS) is a pathologic narrowing within the nasopharynx caudal to the choanae, resulting in a variable degree of inspiratory stertor. This can occur as a congenital anomaly or be secondary to an inflammatory condition, surgery, trauma, or a space-occupying lesion. Traditional therapy involves surgery or serial balloon dilatation procedures. The purpose of the present study was to describe a novel, minimally invasive technique and clinical outcomes following balloon-expandable metallic stent (BEMS) placement for the treatment of benign NPS in veterinary patients.
Four dogs and three cats were diagnosed via computed tomography and rhinoscopy. Using fluoroscopy and retroflex rhinoscopy, a BEMS was advanced over a guidewire through the nares. The stenotic lesion was then dilated to restore patency.
All seven patients presented with severe inspiratory stertor and evidence of upper airflow obstruction. All patients had immediate resolution of signs after stent placement. The procedure took a median of 42 minutes (range 22-70 minutes). One patient had stricture in-growth into the stent resulting in stenosis recurrence, another patient with a very caudal stenosis needed the caudal aspect of the stent trimmed because of hairball entrapment and exaggerated swallowing four months after stent placement. All animals lacked signs of discomfort, had immediate resolution of stertor, and 6/7 were breathing normally at the time of this report (1-20 months after stent placement).
Transnasal BEMS placement represents a short, safe, non-invasive and effective treatment in animals with nasopharyngeal stenosis.