Amniotic Membrane (AM) Covered Airway Stent Mitigates Airway Injury and Complications: A Comparative In Vivo Study in a Porcine Model

BACKGROUND: Airway stenting is a critical intervention to restore airway patency, yet complications such as stent migration, mucostasis, airway injury, and granulation tissue formation remain major concerns. Although various covering materials have been explored, the effectiveness of amniotic membrane (AM) as a stent cover has not been evaluated. This study is the first to assess airway-related complications of a novel AM-covered self-expandable metallic stent (SEMS) compared with a commercially available synthetic polymer-covered SEMS. To compare the incidence of stent-related complications between AM-covered SEMS and synthetic polymer-covered SEMS over a 90-day in vivo survival period. METHODS: Eight adult Yucatan miniswine were implanted with either an AM-covered or control stent and monitored over 90 days with bronchoscopic evaluations at 4 timepoints. Histologic assessments were performed at termination. RESULTS: Seven animals completed the study (4 AM stents, 3 controls). One control animal was terminated early due to stent expectoration. AM-covered stents were associated with reduced stent migration, mucostasis, and granulation tissue formation compared with controls. Histologic analysis revealed significantly less airway injury and evidence of re-epithelialization with cilia in the AM group; a feature absent in control stents. One animal was excluded at implantation and replaced due to a procedural complication unrelated to the stent. CONCLUSION: This is the first study to evaluate stent-related complications of AM-covered airway stents. The results demonstrate that AM-covered SEMS reduce airway injury and common complications associated with synthetic polymer-covered stents. These findings suggest that AM-coverings may enhance biocompatibility and integration while mitigating adverse airway responses. Larger studies and human clinical trials are needed to validate these results and explore clinical application.