title: Granulation formation following tracheal stenosis stenting: influence of stent position.
abstract: OBJECTIVE
  To determine whether stent-to-vocal fold distance influences morbidity following stent placement for tracheal stenosis.
  
  
  METHODS
  Fifty-five stent procedures (46 Montgomery T-tube [Boston Medical Products, Westborough, MA] and 9 Dumon stents [Novatech, Grasse, France]) were performed in 40 patients enrolled in this study.
  
  
  RESULTS
  The most common complication of stenting for tracheal stenosis was granulation (23 procedures, 41.82%). Of 43 procedures where the stent upper edge was located at or below the vocal folds, granulation occurred in 21 procedures (48.84%). Of 12 procedures where the stent edge was located above the vocal fold, granulation occurred in two procedures, or 16.67% (odds ratio = 4.773, P = .0458, chi(2) test). Among patients in whom the stent edge was located at or below the vocal folds, the granulation complication rate was higher in those with a stent-to-vocal fold distance of <10 mm. Multivariate analysis revealed that the stent-to-vocal fold distance independently predicted granulation formation; an inverse correlation was identified between stent-to-vocal fold distance and granulation severity (n = 43, r = -.501, P = .0006; Spearman ranking test). Receiver operating characteristic curve analysis further demonstrated that a stent-to-vocal fold distance cutoff value between 9.5 and 11 mm had the best accuracy in predicting granulation formation.
  
  
  CONCLUSIONS
  A stent-to-vocal fold distance of 10 mm was found to be a critical distance for discriminating granulation formation. Optimal stent-to-vocal fold distance should routinely be evaluated before stent placement.
authors.affiliation: Department of Surgery, Chang Gung Memorial Hospital, School of Medicine, Chang Gung University, Tao-Yuan, Taiwan.
authors.forename: Po-Jen
authors.initials: PJ
authors.lastname: Ko
authors.forename: Chien-Ying
authors.initials: CY
authors.lastname: Liu
authors.forename: Yi-Chen
authors.initials: YC
authors.lastname: Wu
authors.forename: Yin-Kai
authors.initials: YK
authors.lastname: Chao
authors.forename: Ming-Ju
authors.initials: MJ
authors.lastname: Hsieh
authors.forename: Ching-Yang
authors.initials: CY
authors.lastname: Wu
authors.forename: Chao-Jan
authors.initials: CJ
authors.lastname: Wang
authors.forename: Yun-Hen
authors.initials: YH
authors.lastname: Liu
authors.forename: Hui-Ping
authors.initials: HP
authors.lastname: Liu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006097:Granulation Tissue / Q000473:pathology*; D006801:Humans; D007829:Laryngostenosis / Q000209:etiology* / Q000473:pathology / Q000517:prevention & control; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications; D012372:ROC Curve; D012189:Retrospective Studies; D015607:Stents; D014135:Tracheal Stenosis / Q000473:pathology / Q000601:surgery*; D014827:Vocal Cords; D014945:Wound Healing; D055815:Young Adult