In-vivo efficacy of biodegradable ultrahigh ductility Mg-Li-Zn alloy tracheal stents for pediatric airway obstruction

Jingyao Wu,David Chi,Ali Mübin Aral,Leila J Mady,Humberto E Trejo Bittar,Ke Yang,William R Wagner,Feng Zheng,Boeun Lee,Prashant N Kumta,Youngjae Chun,Toma Catalin,Abhijit Roy

doi:10.1038/s42003-020-01400-7

Abstract

Pediatric laryngotracheal stenosis is a complex congenital or acquired airway injury that may manifest into a potentially life-threatening airway emergency condition. Depending on the severity of obstruction, treatment often requires a combination of endoscopic techniques, open surgical repair, intraluminal stenting, or tracheostomy. A balloon expandable biodegradable airway stent maintaining patency while safely degrading over time may address the complications and morbidity issues of existing treatments providing a less invasive and more effective management technique. Previous studies have focused on implementation of degradable polymeric scaffolds associated with potentially life-threatening pitfalls. The feasibility of an ultra-high ductility magnesium-alloy based biodegradable airway stents was demonstrated for the first time. The stents were highly corrosion resistant under in vitro flow environments, while safely degrading in vivo without affecting growth of the rabbit airway. The metallic matrix and degradation products were well tolerated by the airway tissue without exhibiting any noticeable local or systemic toxicity.

Highlights

Pediatric laryngotracheal stenosis is a complex congenital or acquired airway injury that may manifest into a potentially life-threatening airway emergency condition
For the first time, we demonstrate the superior response of a balloon-expandable ultra-high ductility (UHD) biodegradable magnesium tracheal stent contrasted with traditional nondegradable stents
We reported implantation success of prototype magnesium alloy stent in a rat tracheal bypass model[30] and Mg-Li-Zn multiphase UHD alloys for stent application[31] with Mg-6Li-1Zn (LZ61) demonstrating greatest clinical application potential owing to its superior mechanical properties, low degradation rate, UHD of ~50% and excellent biocompatibility

Summary

Introduction

Pediatric laryngotracheal stenosis is a complex congenital or acquired airway injury that may manifest into a potentially life-threatening airway emergency condition. The feasibility of an ultra-high ductility magnesium-alloy based biodegradable airway stents was demonstrated for the first time. Current biodegradable tracheal stents mimicking commercial non-degradable metallic stent design are ineffective for pediatric airway obstruction opening the doors for biodegradable metals for LTS and SGS treatment. For the first time, we demonstrate the superior response of a balloon-expandable ultra-high ductility (UHD) biodegradable magnesium tracheal stent contrasted with traditional nondegradable stents. We reported implantation success of prototype magnesium alloy stent in a rat tracheal bypass model[30] and Mg-Li-Zn multiphase UHD alloys for stent application[31] with Mg-6Li-1Zn (LZ61) demonstrating greatest clinical application potential owing to its superior mechanical properties, low degradation rate, UHD of ~50% and excellent biocompatibility. Our successful results provide early stage preclinical evidence validating the LZ61-KBMS stents potential for pediatric LTS treatment

Methods

Results

Conclusion