Composite Biosynthetic Graft for Repair of Long-Segment Tracheal Stenosis: A Pilot In Vivo and In Vitro Feasibility Study

Abstract

Pediatric patients who undergo surgery for long-segment congenital tracheal stenosis (LSCTS) have suboptimal outcomes and postsurgical complications. To address this, we propose a biosynthetic graft comprising (1) a porcine small intestinal submucosa extracellular matrix (SIS-ECM) patch for tracheal repair, and (2) a resorbable polymeric exostent for biomechanical support. The SIS-ECM patch was evaluated in vivo in an ovine trachea model over an 8 month period. Concurrently, the biosynthetic graft was evaluated in a benchtop lamb trachea model for biomechanical stability. In vivo results show that SIS-ECM performs better than bovine pericardium (control) by preventing granulation tissue/restenosis, restoring tracheal architecture, blood vessels, matrix components, pseudostratified columnar and stratified epithelium, ciliary structures, mucin production, and goblet cells. In vitro tests show that the biosynthetic graft can provide the desired axial and flexural stability, and biomechanical function approaching that of native trachea. These results encourage future studies to evaluate safety and efficacy, including biomechanics and collapse risk, biodegradation, and in vivo response enabling a stable long-term tracheal repair option for pediatric patients with LSCTS and other tracheal defects.