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

Abstract

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

Study design: Animal research study.

Methods: 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.

Results: 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).

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

Level of evidence: NA. Laryngoscope, 127:2219-2224, 2017.

Keywords: TETG; Tissue-engineered trachea; tissue engineering; tracheal dilation; tracheal stenosis; tracheal stenting.