title: An outcome analysis of self-expandable metallic stents in central airway obstruction: a cohort study.
abstract: BACKGROUND
  Self-expandable metallic stents (SEMSs) have provided satisfactory management of central airway obstruction. However, the long-term benefits and complications of this management modality in patients with benign and malignant obstructing lesions after SEMS placement are unclear. We performed this cohort study to analyze the outcomes of Ultraflex SEMSs in patients with tracheobronchial diseases.
  
  
  METHODS
  Of 149 patients, 72 with benign and 77 with malignant tracheobronchial disease received 211 SEMSs (benign, 116; malignant, 95) and were retrospectively reviewed in a tertiary hospital.
  
  
  RESULTS
  The baseline characteristics of patients who received SEMS implantation for benign conditions and those who underwent implantation for malignant conditions were significantly different. These characteristics included age (mean, 63.9 vs. 58; p < 0.01), gender (male, 62% vs. 90%; p < 0.0001), smoking (47% vs. 85%; p < 0.0001), forced expiratory volume in 1 second (mean, 0.9 vs. 1.47 L/s; p < 0.0001), follow-up days after SEMS implantation (median; 429 vs. 57; p < 0.0001), and use of covered SEMS (36.2% vs. 94.7%; p < 0.0001). Symptoms improved more after SEMS implantation in patients with benign conditions than in those with malignant conditions (76.7% vs. 51.6%; p < 0.0001). The overall complication rate after SEMS implantation in patients with benign conditions was higher than that in patients with malignancy (42.2% vs. 21.1%; p = 0.001). Successful management of SEMS migration, granulation tissue formation, and SEMS fracture occurred in 100%, 81.25%, and 85% of patients, respectively.
  
  
  CONCLUSIONS
  Patients who received SEMS implantation owing to benign conditions had worse lung function and were older than those who received SEMS for malignancies. There was higher complication rate in patients with benign conditions after a longer follow-up period owing to the nature of the underlying diseases.
authors.affiliation: Department of Thoracic Medicine, Chang Gung Memorial Hospital, Chang Gung University, College of Medicine, No, 199 Tun Hwa N, Rd, Taipei City 10507, Taiwan.
authors.forename: Fu-Tsai
authors.initials: FT
authors.lastname: Chung
authors.forename: Hao-Cheng
authors.initials: HC
authors.lastname: Chen
authors.forename: Chun-Liang
authors.initials: CL
authors.lastname: Chou
authors.forename: Chih-Teng
authors.initials: CT
authors.lastname: Yu
authors.forename: Chih-Hsi
authors.initials: CH
authors.lastname: Kuo
authors.forename: Han-Pin
authors.initials: HP
authors.lastname: Kuo
authors.forename: Shu-Min
authors.initials: SM
authors.lastname: Lin
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000402:Airway Obstruction / Q000175:diagnosis / Q000209:etiology / Q000628:therapy*; D001999:Bronchoscopy; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D015607:Stents; D016896:Treatment Outcome