Chapter 21: Table of Contents
Surgical options described in the literature include plication of the dorsal tracheal membrane, alternate ring chondrotomy, tracheal resection and anastomosis, and application of extra luminal prostheses. Of these, extraluminal stenting using rings is the surgical technique of choice. Extraluminal stenting is considered a good option for cervical and thoracic inlet collapse but not for intrathoracic or mainstem bronchus collapse. Using a cervical approach with cranial traction, prosthetic rings can generally be applied to the level of the second intercostal space.
Risks of iatrogenic trauma to the laryngeal nerves and tracheal blood supply can lead to laryngeal paralysis and tracheal necrosis. Rings can be purchased or cut from syringe casings or barrels of appropriate size and autoclaved prior to use. Retrospective evaluation of 90 cases of extraluminal polypropylene ring application revealed an overall success rate of 75-85% with 6% perioperative mortality rate, 31% immediate postoperative complication rate (24% coughing, 16% dyspnea, and 11% laryngeal paralysis). 19% of cases underwent permanent tracheostomy, half within 24 hours of the procedure. Results of this study suggested that age was the only prognostic factor with dogs less than 6 years old having worse tracheal collapse but a better outcome. Smaller studies have reported lower complication rates but it appears that dogs with cardiac or lung disease, with laryngeal paralysis (~30% of cases) and mainstem bronchus collapse (~50% of cases) have a worse prognosis. Dogs with tracheal and mainstem bronchus collapse may still benefit from extraluminal stents to correct the tracheal collapse but owners should be warned that improvement may be minimal. If laryngeal paralysis is documented, a laryngeal tie-back should also be performed.