03:36 PM Abstract No. 407 Tracheobronchial bioabsorbable stent: experimental study in an animal model

Abstract

To study the tracheal pathology response after a polydioxanone bioabsorable stent (BAS) implantation in a rabbit model. Twenty two rabbits (4.61±0.52 Kg), divided into 3 groups with different survival time were compared: group 30 (30 days, n=7), group 60 (60 days, n=7) and group 90 (90 days, n=8); one rabbit in each group was a control animal. The bioabsorbable stents (8x30 mm) were implanted through a tracheotomy and fluoroscopy guidance. Respiratory tissue response was assessed by CT and tracheoscopy, and in all cases an hystopathological study was performed. The trachea was divided into five sections for analysis (A: central segment of the stent; B1: cranial stent ending; B2: caudal stent ending; C1: cranial fragment to the stent; C2: caudal fragment to the stent). Presence of radiopaque markers (RM) and granuloma were evaluated and the tracheal wall thickness and lumen were measured. Technical success was a 100%. RM were observed in CT images in all animals after 30 days; however only in 50% of all cases in 60 days and absence of RM at 90 days. Significant differences were observed regarding tracheal area and wall thickness when the stent was present. Granulomas were found in 7 animals (3 in group 30, 2 in group 60 and 2 in group 90), and they were located in: B1 (n=3), C1 (n=3), and A (n=1). BAS were degradated around 60 days after deployment, and no clinical complication were observed. In all animals the tracheal patency was 100%. BAS is a very promising alternative in airway obstruction; nevertheless, posterior studies are necessary.