Endoscopic management of tissue-engineered tracheal graft stenosis in an ovine model

To evaluate the safety and efficacy of bronchoscopic interventions in the management of tissue-engineered tracheal graft (TETG) stenosis.

Animal research study.

TETGs were constructed with seeded autologous bone marrow-derived mononuclear cells on a bioartificial graft. Eight sheep underwent tracheal resection and orthotopic implantation of this construct. Animals were monitored by bronchoscopy and fluoroscopy at 3 weeks, 6 weeks, 3 months, and 4 months. Bronchoscopic interventions, including dilation and stenting, were performed to manage graft stenosis. Postdilation measurements were obtained endoscopically and fluoroscopically.

Seven dilations were performed in six animals. At the point of maximal stenosis, the lumen measured 44.6 ± 8.4 mm² predilation and 50.7 ± 14.1 postdilation by bronchoscopy (P = 0.3517). By fluoroscopic imaging, the airway was 55.9 ± 12.9 mm² predilation and 65.9 ± 22.4 mm² postdilation (P = 0.1303). Stents were placed 17 times in six animals. Pre- and poststenting lumen sizes were 62.8 ± 38.8 mm² and 80.1 ± 54.5 mm² by bronchoscopy (P = 0.6169) and 77.1 ± 38.9 mm² and 104 ± 60.7 mm² by fluoroscopy (P = 0.0825). Mortality after intervention was 67% with dilation and 0% with stenting (P = 0.0004). The average days between bronchoscopy were 8 ± 2 for the dilation group and 26 ± 17 in the stenting group (P = 0.05). One hundred percent of dilations and 29% of stent placements required urgent follow-up bronchoscopy (P = 0.05).

Dilation has limited efficacy for managing TETG stenosis, whereas stenting has a more lasting clinical effect.

NA. Laryngoscope, 127:2219-2224, 2017.