Reactivity Study of a Biodegradable Polydioxanone Tracheal Stent in a Rabbit Model. / Stent traqueal biodegradable de polidioxanona. Estudio de la reactividad en conejo.

INTRODUCTION: The objective of this study was to evaluate tracheal reactivity induced by a biodegradable polydioxanone tracheal stent. MATERIALS AND METHODS: Twenty-two rabbits were divided into 3 groups assigned to different survival times (30, 60 and 90days post-implantation). A biodegradable stent was implanted in each animal, except for 1 of each group (negative control). Implantation was performed through a small tracheotomy under fluoroscopic control. CT and histopathological studies were scheduled at the end of survival times. RESULTS: No animal died during the procedure or follow-up. The stent had disappeared in 100% of the cases at 90days, in 50% at 60days, and in none at 30days. CT studies revealed a greater tracheal wall thickness at 30days than at 60 and 90days (1.60±0.41mm in the central part of the stent versus 1.11±0.18 and 0.94±0.11; P=.007, respectively). No granulomas were observed on histopathology. Some degree of histological changes were noted at 30days, which had reduced at 60 and 90days. Differences were also found in both CT and histology between animals in which the stent was present and animals in which it had degraded. CONCLUSIONS: Polydioxanone stents produce a mild reaction that reverts with tracheal degradation. The use of these biodegradable stents in benign tracheal disease is promising.