title: Granulation tissue formation following Dumon airway stenting: the influence of stent diameter.
abstract: OBJECTIVE
  The present study aimed to determine whether stent diameter influences granulation tissue formation following stent placement for major airway stenosis.
  
  
  METHODS
  Forty-two stent procedures (32 tracheal stents, 3 carinal stents, and 7 bronchial stents) were performed in 40 patients. Seventy-nine stent edge regions (62 tracheal, 17 bronchial stents) were evaluated in this study.
  
  
  RESULTS
  Granulation tissue formation was encountered in 11 patients (28.21%). Of the 34 upper ends of evaluated tracheal stents, granulation tissue formation was observed in 6 (17.65%), whereas granulation tissue formation was observed in 2 (7.14%) of the 28 lower ends of tracheal stents evaluated. Of the 17 bronchial stent edge regions, granulation tissue formation occurred in 3 (17.65%) ( P = 0.4352). The rate of granulation tissue formation was higher in those patients with a stent-to-airway diameter ratio of > 90% ( P < 0.0001). Receiver operating characteristic curve analysis further demonstrated that a cut-off stent-to-airway diameter ratio of 90% was effective in predicting granulation tissue formation (AUC: 0.897, Std. error = 0.036, P < 0.0001, 95% CI = 0827-0.968, n = 79).
  
  
  CONCLUSIONS
  A stent-to-airway diameter ratio of 90% was found to be the critical cut-off point for predicting granulation tissue formation. Therefore, the optimal stent-to-airway diameter ratio should be ascertained before stent placement.
authors.affiliation: Department of Thoracic Medicine, Chang Gung Memorial Hospital, Taipei, Taiwan, Province of China.
authors.forename: H-C
authors.initials: HC
authors.lastname: Hu
authors.forename: Y-H
authors.initials: YH
authors.lastname: Liu
authors.forename: Y-C
authors.initials: YC
authors.lastname: Wu
authors.forename: M-J
authors.initials: MJ
authors.lastname: Hsieh
authors.forename: Y-K
authors.initials: YK
authors.lastname: Chao
authors.forename: C-Y
authors.initials: CY
authors.lastname: Wu
authors.forename: P-J
authors.initials: PJ
authors.lastname: Ko
authors.forename: C-Y
authors.initials: CY
authors.lastname: Liu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003251:Constriction, Pathologic; D005260:Female; D006097:Granulation Tissue; D006801:Humans; D008297:Male; D008875:Middle Aged; D012140:Respiratory Tract Diseases / Q000473:pathology*; D015607:Stents