title: Experimental absorbable stent permits airway remodeling.
abstract: OBJECTIVE
  Despite metallic and silicone stents being effective in treating various airway lesions, many concerns still remain. A bioresorbable stent that scaffolds the airway lumen and dissolves after the remodeling process is completed has advantages over metallic and silicone stents. We designed and fabricated a new mesh-type bioresorbable stent with a backbone of polycaprolactone (PCL), and evaluated its safety and biocompatibility in a rabbit trachea model.
  
  
  METHODS
  The PCL stent was fabricated by a laboratory-made microinjection molding machine. In vitro mechanical strength of the PCL stents was tested and compared to that of commercial silicone stents. The bioresorbable stents were surgically implanted into the cervical trachea of New Zealand white rabbits (n=6). Animals received bronchoscopic examination at 1, 2, 4, 8, and 12 weeks after surgery. Histological examination was completed to evaluate the biocompatibility of the stents.
  
  
  RESULTS
  No animals died during the period of study. Distal stent migration was noted in 1 rabbit. In-stent secretion accumulation was found in 2 rabbits. Histological examination showed intact ciliated epithelium and marked leukocyte infiltration in the submucosa of the stented area at 10 and 28 weeks. Stent degradation was minimal, and the mechanical strength was well preserved at the end of 33 weeks.
  
  
  CONCLUSIONS
  These preliminary findings showed good safety and biocompatibility of the new PCL stent when used in the airway remodeling. PCL could be a promising bioresorbable material for stent design if prolonged degradation time is required.
authors.affiliation: Department of Mechanical Engineering, Chang Gung University, and Department of Thoracic and Cardiovascular Surgery, Chang Gung Memorial Hospital, Kwei-Shan, Tao-Yuan, Taiwan.
authors.forename: Kuo-Sheng
authors.initials: KS
authors.lastname: Liu
authors.forename: Yun-Hen
authors.initials: YH
authors.lastname: Liu
authors.forename: Yi-Jie
authors.initials: YJ
authors.lastname: Peng
authors.forename: Shih-Jung
authors.initials: SJ
authors.lastname: Liu
mesh_terms: D020341:Absorbable Implants; D056151:Airway Remodeling; D000818:Animals; D001999:Bronchoscopy; D005548:Foreign-Body Migration / Q000209:etiology; D008422:Materials Testing; D011091:Polyesters; D011474:Prosthesis Design; D011817:Rabbits; D015607:Stents / Q000009:adverse effects; D013314:Stress, Mechanical; D013997:Time Factors; D014132:Trachea / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*
chemical_list: D011091:Polyesters; C016240:polycaprolactone