Development of a 3D-printed synthetic tracheal scaffold for partial tracheal wall reconstruction: an experimental...

Tracheal reconstruction remains a significant clinical challenge due to the difficulty of maintaining airway patency and promoting epithelial regeneration following tracheal injury or resection. Recent advances in tissue engineering have explored 3D-printed scaffolds as potential solutions; however, limitations remain regarding scaffold biocompatibility, mechanical stability, and integration with host tissue. This study evaluated the feasibility of a non-biodegradable polyurethane-polyvinyl chloride (PU-PVC) composite scaffold for partial tracheal wall reconstruction in a rabbit model.

Nine New Zealand white rabbits underwent anterior tracheal wall reconstruction using a customized half-pipe PU-PVC scaffold. Scaffold mechanical properties were characterized before implantation. Animals were monitored for 30 days, after which bronchoscopic evaluation was performed to assess luminal patency. Histological analysis was conducted to evaluate epithelialization and inflammatory response. Explanted scaffolds were also assessed for structural integrity and mechanical stability.

The 30-day survival rate was 88.9% (8/9; 95% CI 51.8%-99.7%), with one death occurring on postoperative day 14. Bronchoscopic examination demonstrated complete luminal patency in all surviving animals, with no evidence of stenosis, obstruction, or mucus plugging. Histological findings demonstrated variable epithelialization, with 50% (4/8) of rabbits showing favorable epithelial coverage accompanied by mild inflammation, while the remaining animals exhibited partial or minimal epithelialization associated with greater inflammatory responses. Post-explant evaluation demonstrated preservation of scaffold structure and mechanical properties, with only minor changes in tensile strength and porosity after implantation.

In this preliminary single-cohort feasibility study, the PU-PVC composite scaffold-maintained airway patency throughout the 30-day observation period and demonstrated acceptable short-term mechanical stability following partial tracheal wall reconstruction in a rabbit model. Although epithelialization outcomes were variable and no comparator group was included, the findings support further preclinical investigation of this scaffold platform; however, long-term safety, durability, and biological integration remain to be established. Future studies incorporating appropriate control groups, longer follow-up periods, quantitative assessments of airway patency, and bioactive modifications such as cell seeding or growth factors are warranted to enhance tissue regeneration and better define the scaffold's translational potential.