Nitinol wire stent relieves severe tracheal narrowing in eclectus

Abstract

A 25-year-old, female eclectus parrot (Eclectus roratus) presented for dyspnea 3 weeks after anesthesia and surgery for egg yolk coelomitis. Radiography, computed tomography, and tracheoscopy revealed multiple tracheal strictures spanning a length of 2.6 cm in the mid to distal trachea. Histopathologic examination revealed mild fibrosis, inflammation, and hyperplasia consistent with acquired tracheal strictures. Tracheal resection was not considered possible because of the length of the affected trachea. The strictures were resected endoscopically, and repeated balloon dilation under fluoroscopic guidance over the course of 10 months resulted in immediate but unsustained improvement. Computed tomography was used to measure the stenotic area. A 4 × 36-mm, custom-made, nitinol wire stent was inserted into the trachea under fluoroscopic guidance. After stent placement, intermittent episodes of mild to moderate dyspnea continued, and these responded to nebulization with a combination of saline, acetylcysteine, and dexamethasone. Multiple attempts to wean the patient off nebulization therapy and to switch to a corticosteroid-free combination were unsuccessful. The parrot eventually developed complications, was euthanatized, and necropsy was performed. Histologically, the tracheal mucosa had widespread erosion to ulceration, with accumulation of intraluminal exudate and bacteria, severe degeneration of skeletal muscle and tracheal rings, prominent fibrosis, and mild to moderate, submucosal inflammation. Clinicopathologic findings in this case suggested tracheomalacia, which has not been previously described in birds. Custom-made tracheal stents can be used for severe tracheal stenosis in birds when tracheal resection and anastomosis is not possible. Complications of tracheal stent placement in birds may include tracheitis and tracheomalacia. To our knowledge, this is the first report of tracheal stent placement in an avian species.