Use of internal bioabsorbable PLGA "finger-type" stents in a rabbit tracheal reconstruction model

Objectives: To design and develop a biodegradable tracheal stent that can b e used internally to stabilize and support surgically reconstructed airways . Design: In vitro mechanical and degradative properties of 80:20 poly(D,L-la ctide-co-glycolide) (PLGA) "finger-like" stents were determined. The stents were then tested in vivo in rabbits that underwent anterior patch tracheop lasties with fascia lata grafts. Comparisons were made between a control gr oup and an internal stent group for strider development, overall group mort ality, reconstructed airway lumen size, and histological findings. Subjects: Twenty-five New Zealand white rabbits. Results: The average dry modulus for the internal stents was 6800 kPa. All of the internal stents cracked by 4 weeks in buffer solution. Significant m ass loss was not noted in vitro until after 5 weeks in buffer solution. By 14 weeks, the stents were nearly 100% degraded. The attrition rate for the control group was 23% compared with 17% for the experimental group. The str ider rate for the control group was also higher at 38% compared with 17% fo r the stented group. The stented rabbits had a significantly smaller averag e stenosis (23%) across the entire reconstruction site than the control gro up (34%) (P<.05). Conclusion: Biodegradable PLGA stents degrade in a predictable fashion-and have a statistically significant effect in augmenting anterior patch trache oplasties with fascia lata grafts in rabbits.