Tracheal External Support Using a Parallel Loop Line Prosthesis for Tracheal Stent Fracture in a Dog: A Case Report.

Tracheal stent fracture is a major complication of endoluminal tracheal stent (ELS) for canine tracheal collapse, and optimal management strategies remain unclear. A 4-year-old Yorkshire Terrier presented with respiratory distress caused by complete ELS fracture. Imaging and bronchoscopy revealed intraluminal protrusion of fractured stent segments, ventral tracheal cartilage invagination, and marked luminal deformation. A parallel loop line prosthesis (PLLP) was selected as an external tracheal support. Its continuous band-like structure allowed broad and uniform reinforcement of the tracheal wall and redistribution of mechanical stress. PLLP placement successfully restored a near-normal tracheal contour and stabilized the fractured stent without introducing additional intraluminal material. Postoperative bronchoscopy confirmed improved tracheal patency, and no further deformation or stent damage was observed despite several months of altered airway dynamics associated with laryngeal paralysis. This case suggests that PLLP may represent a valid surgical option for managing tracheal stent fracture in dogs.