# The Local Damage and Systemic Inflammation Induced by a Biodegradable Polydioxanone Stent Implanted in the Rabbit Trachea Decreases Markedly with Stent Degradation

## TL;DR

A biodegradable tracheal stent causes less inflammation and damage over time as it degrades in rabbits.

## Contribution

This study shows that inflammation and local damage from a polydioxanone stent decrease as the stent degrades.

## Key findings

- Tracheoscopic findings showed reduced congestion, inflammation, and secretions after stent degradation.
- IL-8 levels in tracheal lavage decreased significantly after stent degradation.
- Blood IL-8 levels increased initially but decreased over time.

## Abstract

Biodegradable tracheal stents have been developed to overcome the limitations of metallic and removable stents in benign airway disease. This study evaluated the local and systemic inflammatory response induced by a biodegradable polydioxanone tracheal stent in a rabbit model. Twenty-one rabbits were assigned to three follow-up groups (30, 60, and 90 days). In each group, six animals received a tracheal stent, and one served as a sham control. Clinical status and respiratory symptoms were monitored, and serial peripheral blood interleukin-8 (IL-8) levels were measured. At the end of follow-up, tracheoscopy, IL-8 quantification in tracheal lavage, and necropsy were performed. No deaths or severe respiratory symptoms occurred. Tracheoscopic findings were significantly less severe after stent degradation, with reduced congestion (p = 0.030), inflammation (p = 0.003), and secretions (p = 0.030). Two granulomas and two cases of stenosis were identified. Mean IL-8 expression in tracheal lavage (relative quantification, RQ) was 14,129 ± 3007 when the stent was present and 426 ± 100 after degradation (p = 0.003). Blood IL-8 expression increased significantly on day 1 compared with baseline (p = 0.022) and subsequently decreased (p = 0.034). Inflammatory and structural alterations induced by a polydioxanone tracheal stent decrease after stent degradation.