Mechanical characteristics of different braiding methods used in canine self-expanding tracheal stents

Tracheal collapse is a common respiratory disorder in small-breed dogs. Endoluminal stenting has become an important minimally invasive treatment option, particularly when medical management fails. Nevertheless, stent fracture remains a major postoperative complication, prompting the development of stents with alternative braided structures to improve durability and mechanical performance.

This study compared the mechanical properties of two self-expanding nitinol tracheal stents with different braided patterns-a conventional cross-braided design and a cross-and-hook braided design-to assess their mechanical characteristics and potential suitability for use in dogs.

Mechanical testing was performed on two commercial veterinary tracheal stents: a cross-braided stent and a cross-and-hook braided stent (Fauna stent; M.I.TECH. Co. Ltd, Korea). The flexural stiffness was assessed using a three-point bending test, while the radial and axial mechanical strengths were evaluated using compression and tensile tests, respectively.

The cross-and-hook braided stent showed greater bending flexibility and slightly higher radial stiffness than the cross-braided stent. Both stents showed comparable tensile resistance within the physiological deformation ranges. The cross-and-hook structure also retained its cell geometry under compression and resisted permanent deformation more effectively.

The cross-and-hook braided stent showed trends toward improved mechanical properties relevant to the clinical performance in dogs, with possible benefits in reducing stent fatigue and rupture. These findings highlight its potential suitability for managing tracheal collapse in dogs and may help guide future development of veterinary and human stents.